Water treatment and desalination

Abstract

Embodiments of the present invention provide systems and methods for water treatment and / or desalination.

Description

Water treatment and desalination Due to the well-known increasing shortage of water resources, the urban distribution system of drinking water degrades over time, and the increased use of water causes wear and tear on wells and storage tanks, resulting in the pollution of physiological saline water. Therefore, water purification technology has quickly become a necessary aspect of modern life. In addition, water sources are further polluted by various activities, including, for example, intensive agriculture, gasoline additives, and toxic heavy metals. These problems have led to an increasing and unpleasant content of germs, bacteria, salts, MTBE, chlorates, perchlorates, arsenic, mercury, and even chemicals used to sterilize drinking water in water systems. Well-known desalination and water treatment technologies, such as filtration systems (such as reverse osmosis (RO) and forward osmosis (FO)) and thermal distillation systems (such as multi-effect distillation (MED), multi-stage flash distillation (MSF), membrane distillation, or vapor compression distillation (VC)), rarely can handle the various ranges of water pollution seen in physiological saline water and other industrial and urban environments. In addition, although it is available, it usually requires multiple treatment stages or a combination of various technologies to obtain acceptable water quality. Therefore, a complex distillation system that operates continuously, resists corrosion, compaction, can recover the main input water part, is relatively inexpensive, and requires less maintenance will be the longest-term option for solving the increasing water pollution problem and water scarcity worldwide. There is also a need for industrial and urban desalination and water treatment systems with the aforementioned characteristics, which can also produce high-concentration waste brine / concentrate / solution that crystallizes into a slurry or solid salt cake for disposal or recovery of solids. The present invention relates to heat pipes or other similar phase change devices such as heat syphons, heat plates, annular heat pipes, pulsating heat pipes, or combinations of such devices as basic elements for heat transfer in distillation, water purification, feed water concentration, and steam generation systems. When referring to the systems in this specification, the term "distillation system" may be used and may include all of the前述 types of systems. Embodiments of the present invention cost-effectively produce water with a purity sufficient for reuse applications that are significantly more beneficial than many prior art techniques (such as high-pressure boilers, agriculture, etc.). Although the ability of any system to remove contaminants from the inlet feed water is to some extent a function of the total impurity content in the inlet feed water, the systems of the present invention are particularly well-suited to removing multiple different types of contaminants from a single feed stream, thereby producing water comparable to distilled water obtained from prior art techniques and in some cases comparable to ultrapure water. Embodiments of the present invention can produce concentrated brine or valuable concentrated chemical solutions or both for use in food, commercial, industrial, and other applications. Embodiments of the present invention can also produce concentrates that are easier and less costly to recover or process than the more dilute solutions from which they are derived. Embodiments of the present invention can produce crystalline solids that are disposed of or recovered when the solids are valuable. Embodiments of the present invention can produce steam for various industrial and commercial applications such as heating, other HVAC, food processing and canning, cleaning, power generation, paper making, enhanced oil recovery, beer production, brick production, reagent production for chemicals, and / or the like. The energy source of the system of the present invention can be any available energy source or combination of energy sources, including (but not limited to) any one or any combination of the following: steam, electricity, natural gas furnaces, oil furnaces, coal furnaces, chemicals, chemical reactions, solar energy, nuclear energy, geothermal energy, molten salts, heat transfer fluids, biomass, compost, fermentation, microwaves, flue gases, solid waste, alcohol furnaces, incinerators, hydrocarbon furnaces, and waste heat from industrial or other processes. The feed solution entering embodiments of the present invention can be an aqueous solution with contaminants to be purified. It can also be an aqueous solution to be concentrated, where the final product of the system is the final concentrate rather than purified water or other than purified water. The feed solution can also be non-aqueous. The term feed water in the present invention can include all such cases. In water purification applications, the system is capable of removing one or more types of contaminants from a contaminated water sample, including microbial contaminants, radiological contaminants, metals, salts, volatile organic compounds, suspended solids, non-volatile organic compounds, and / or the like. Embodiments of the present invention relate to water purification and / or desalination systems that include a plurality of fluid processing components and heat transfer components in at least one stage and a control system. In some embodiments, the fluid processing components of at least one stage can define a fluid processing path for the fluid flow from one or more water inlets to at least one outlet of at least one product and at least one waste product of at least one waste product.In some embodiments, each component along the fluid processing path may be in fluid communication with at least one adjacent fluid processing component stream, and the fluid processing components in the order of fluid flow may include: a water inlet, an evaporation chamber, a purified water condensation chamber, and the outlets. In operation, the heat transfer component may provide distillation energy. The heat transfer component may include at least one of the following: a heat pipe, a hot plate, a radiator, an annular heat pipe, or a pulsating heat pipe, or a combination of such devices, and wherein the heat transfer component defines a heat recovery mechanism. The system may further include at least one additional feature selected from the following: (a) process variations; (b) hardware configurations in stages; (c) adaptations for scale prevention, cleaning, or maintenance; (d) adjuvant purification schemes; and (e) any combination thereof. In some embodiments, the process variations may be selected from the group consisting of: applying a vacuum, vapor recompression, product water feedback, single-stage core, vapor compression evaporation, and / or any combination thereof. In some embodiments, the hardware configuration may be in at least one stage. In some embodiments, the configuration may be selected from the group consisting of: water spray, annular heat pipe, horizontal orientation, at an angle between horizontal and vertical, or oriented along an axis different from the horizontal and vertical axes, heat pipes of unequal height, heat pipes at unequal positions in at least one chamber of a stage, steam injection variations, heat pipe installation schemes, heat pipes in a plate configuration, a hot plate as a chamber wall, and any combination thereof. In some embodiments, the adaptations for scale prevention, cleaning, or maintenance may be selected from the group consisting of: softening by ultrafiltration or nanofiltration, softening by ion exchange, softening by precipitation, removal from the operation of one stage, chemical treatment, dual degasser, thermal shock, robotic cleaning, coating, electrical biasing on the heat pipe, and any combination thereof. In some embodiments, the adjuvant purification schemes may be selected from the group consisting of: multi-effect distillation (MED), multi-stage flash (MSF), freezing, membrane distillation, reverse osmosis, forward osmosis, and any combination thereof. In some embodiments, the system may include at least two additional features. In some embodiments, the at least two additional features may be selected from the same group. In some embodiments, the at least two additional features may be selected from different groups. In some embodiments, the system may include at least one additional feature from each group. For a system for purifying water, when the content of the types of contaminants in the contaminated water is 25 times or greater than the content shown in the MCL column of Table 1, the system may be operated such that the content of all types of contaminants in the water purified in the system is lower than the content shown in the MCL column of Table 1. However, when the system is used for industrial waste streams or desalinated seawater, for example, the feed water contaminant content may be significantly higher than that shown in Table 1, but the purified water contaminant content after system treatment may be similar to that shown. Although the ability of any system to remove contaminants from the inlet water is to some extent a function of the total impurity content in the inlet water, the system of the present invention may be particularly well-suited to removing multiple different types of plural different contaminants from a single feed stream, thereby producing water equivalent to distilled water obtained from conventional techniques and in some cases equivalent to ultrapure water.Note that the "Challenge Water" column in Table 1 contains the pollutant concentration levels of the water used in the EPA tests. Embodiments of the water purification system of the present invention can generally remove a greater amount of initial pollutants than the amounts listed in this column. The contaminant levels corresponding to those mentioned in the "Challenge Water" column are also well within the capabilities of embodiments of the present invention. Table 1 - EPA Test Water. The determination of water purity and / or purification performance efficiency can be based on the system's ability to remove a large number of contaminants. For many biological contaminants, the goal is to remove substantially all live contaminants. Table 2 lists additional common contaminants in the water source and the standard protocols for testing contaminant levels. The protocols listed in Tables 1 and 2 are publicly available at the U.S. Environmental Protection Agency website (http: / / www.epa.gov / safewater / mcl.html #mcls) regarding common water contaminants; Methods for the Determination of Organic Compounds in Drinking Water, EPA / 600 / 4-88-039, December 1988, revised July 1991. Methods 547, 550, and 550.1 are found in Methods for the Determination of Organic Compounds in Drinking Water - Supplement I, EPA / 600-4-90-020, July 1990. Methods 548.1, 549.1, 552.1, and 555 are found in Methods for the Determination of Organic Compounds in Drinking Water - Supplement II, EPA / 600 / R-92-129, August 1992. Methods 502.2, 504.1, 505, 506, 507, 508, 508.1, 515.2, 524.2, 525.2, 531.1, 551.1, and 552.2 are found in Methods for the Determination of Organic Compounds in Drinking Water - Supplement III, EPA / 600 / R-95-131, August 1995. Method 1613 is titled "Tetra-through OctaChlorinated Dioxins and Furans by Isotope- Dilution HRGC / HRMS", EPA / 821- B-94-005, October 1994. Each of the foregoing is incorporated herein by reference in its entirety. Table 2 - Additional Common Contaminants Embodiments of the system can produce a certain volume of purified water, which can be between about 10% and about 99% of the feed volume. In the case of concentrating the feed stream using the system, depending on the system operating configuration and the solute or solid species involved, the feed can be concentrated from a concentration of less than one percent to a concentration of 50% or greater. The system can be configured in a vertical stack configuration, a horizontal configuration, a combination of vertical stack and horizontal configuration, or a horizontal configuration of an evaporation chamber, a condensation chamber, and a preheater, all of which are in a fixed or mobile device of any system size from less than 5 gallons per day to hundreds of millions of gallons per day or more of the feed water being processed. Component parts of the system By using heat pipes or other phase change heat transfer elements (such as thermosyphons, hot plates, annular heat pipes, etc.), embodiments of the present invention provide a water purification system and a feed water concentration system that include some or all of a combination of components selected from the following list: a pretreatment system, one or more degassers, one or more preheaters, one or more evaporation chambers, one or more demisters, one or more product condensation chambers, one or more energy input pipes, one or more inlets and outlets for liquid, solid, and gas flows, a control system, one or more heat recovery units, and one or more energy sources. The system can also include one or more heat exchangers for capturing and reusing the heat contained in various internal concentrated streams, vapor streams, and purified water streams. The system can also include one or more cooling water sources and a heat exchange system for supplying the cooling water to some or all of the heated concentrate, vapor stream, or purified water stream. The goal of the pretreatment system can be to reduce the scale-forming compounds to a level that does not interfere with the performance of the system by forming scale in subsequent treatment and desalination equipment, or to reduce the effect of the scale-forming compounds during desalination. Water hardness is usually defined as the amount of calcium (Ca++), magnesium (Mg++), and other divalent ions present in water, and is usually expressed as parts per million (ppm) of these ions or their equivalents (such as calcium carbonate (CaCO3)). In some environments, scale forms because water dissolves carbon dioxide from the atmosphere, and this carbon dioxide provides carbonate ions that combine to form calcium carbonate and magnesium carbonate. When heated, the solubility of calcium carbonate and magnesium carbonate decreases significantly, and they precipitate as scale. In fact, scale includes any chemical compound that precipitates from solution. Thus, iron phosphate and calcium sulfate (gypsum) also produce scale. The following table (Table 3) lists various compounds that exhibit low water solubility and can therefore form scale. In this case, low solubility is defined by the solubility product, that is, by the product of the ionic concentrations of the cations and anions of a particular chemical substance; solubility is usually expressed in moles per liter (mol / L). Table 3: Solubility products of various compounds Embodiments of the system may include all or only some of the components from the previous component list. For example, when the water to be treated does not contain volatile organic compounds, a degasser may not be required. As another example, when the water to be treated is already at a high temperature, a preheater may not be required. As another example, the product water may be directed back to a previous stage and collected at a single product outlet rather than multiple outlets. There are many other examples where only some of the previously listed components are needed. However, the basis of the system includes at least one evaporation chamber and one heat pipe or a set of heat pipes. This application claims the benefit of U.S. Provisional Patent Application No. 62 / 456,064, filed Feb. 7, 2017, and U.S. Provisional Patent Application No. 62 / 468,819, filed Mar. 8, 2017, the entire disclosures of which are incorporated herein by reference in their entirety. Typical System Configuration In some embodiments of the present invention, the feed water or solution to be concentrated is delivered to a preheater to bring it from ambient temperature to near boiling temperature. The feed water is delivered from the preheater to a degasser to remove unwanted volatile compounds. The feed water is delivered from the degasser to the first steam generation stage of the system. In this stage, heat is applied to the feed water using a heat pipe (or other phase change heat transfer device) until the feed water boils. The steam generated in this first "stage" is delivered to the condensation chamber of the preheater stage, where it condenses into purified water. The energy to vaporize this steam is transferred from the steam to the feed water in the preheater. Some of the concentrates in the first boiling point are delivered to the next stage, where it boils again to produce steam, which then condenses and its energy is transferred to another volume of concentrate, etc. The repetition of the energy transfer allows the original energy supplied to the system to be reused, thus making the present invention energy efficient. It should be noted that the feed water can travel in the same direction as the energy in the heat pipe or in the opposite direction between the stages. Similarly, the feed water can be fed independently into individual stages. The purified water can be collected individually from each condensation chamber, or it can be transferred between the stages to capture the heat it contains. The concentrates and purified product water can be transferred between the stages using pumps, hydrostatic pressure, or the internal pressure of the higher temperature stages. In addition, it should be noted that not all systems need to have all of the listed components, and some systems may have more. For example, in a stage, when the feed water contains scale-forming compounds that need to be removed before treatment, a pretreatment system can be added. As a second example, when the concentrate is the desired final product, a demister may not be required. As a third example, for applications that require balancing energy efficiency and capital cost, the number of stages can be any number selected from one to twenty or greater. Typical Embodiment An embodiment of a water purification and desalination system is shown in FIG. 1. This embodiment consists of: a preheater 10 , a degasser 15 , two evaporation chambers (boilers) 20 , heat pipes 25 , two demisters 30 , two condensation chambers 35 and an energy input container 40, in which case the energy input container is another condensation chamber. Feed water to be purified or concentrated 45 is introduced into the preheater 10. After preheating, the feed water 45 is delivered via a deaerator 15 to the first evaporation chamber 20, in which the heat energy transferred from the corresponding condensation chamber 25 via the heat pipes causes steam to be generated 35 from some of the deaerated feed water 75. The remaining feed water (intermediate concentrate 50. The remaining feed water (intermediate concentrate 70) is delivered to the next evaporation chamber, where some of the remaining feed water is again converted into steam by the energy of the heat pipes from another corresponding condensation chamber. The feed water and the intermediate concentrate are concentrated in each evaporation chamber until the final concentrate stream 55 (produced in the last evaporation chamber) is discharged from the system via the concentrate outlet. The energy of the system 60 is provided to the energy input container 40. This energy is used to generate steam 20 from the intermediate concentrate stream 70 in the corresponding evaporation chamber 30. The steam thus generated is transferred via the demister 35 to the condensation chamber 25, where the energy in the steam is recovered by the heat pipes 65 when the steam condenses. The condensed steam leaves the condensation chamber as purified water 25. The heat pipes in the condensation chamber 20, where more steam is generated. Repeat this process until the condensation chamber connected to the preheater transfers its condensed steam energy to the preheater to preheat the feed water. Many other embodiments are possible. For example, feed water can be introduced at the other end of the system to create a "cocurrent" system. As another example, the feed water can be introduced directly into each evaporation chamber rather than flowing between the chambers. Many other configurations are possible. Another embodiment of the water purification system is shown in FIG. 2. Here, the system includes a pretreatment section, a deaerator, a preheater, one or more evaporation chambers and demisters, one or more product condensation chambers, inlets and outlets for liquid and gas flows, a control system, one or more heat recovery units, equipment for regulating and in-place cleaning procedures, and equipment for removing solids. It is obvious to anyone skilled in the art that although FIG. 2 includes all these steps, a system without one or more of these steps is also possible. The feed water to be purified 45 is fed into one or more pretreatment units 115, such as softening the water by ion exchange resins, precipitation, (by adding chemicals or by adjusting the pH value), filtration, coagulation, sedimentation, or centrifugation. After pretreatment, the pretreated feed water 80 is transferred to the next stage by the action of a pump or hydrostatic pressure, while solids can be removed from the unit 85. The pretreatment step can be used to separate scale-forming impurities from the feed water to inhibit scale formation on the inner surfaces of the units downstream of the pretreatment unit. In some embodiments, the feed water is not pretreated. The pretreated feed water 80 is transferred to one or more preheater units 10. The preheater unit transfers heat from the process stream or an external heat source to the feed water. The preheater unit can include a heat exchanger, a hot plate, a heat pipe, a pipe, or a rod. Some examples of heat sources are the steam generated in the evaporation chamber, the steam generated from the flashing pressurized water in the process vessel, the steam from an external supply, purified water, the concentrate, or a combination of these substances. In a typical setup, the feed water is preheated to a temperature between the starting temperature of the feed water and the boiling point of the feed water in the first evaporation chamber (including the boiling point elevation caused by the dissolved solids in the feed water). In one embodiment, the first preheater is a heat exchanger with purified water 65 as the energy source, and the second preheater is a container with heat pipes, and the energy source is the steam from evaporation chamber 90A with the lowest temperature in the water purification system. The preheated feed water 95 may include chemical species with relatively low vapor pressures, such as volatile organic compounds, other organic liquids, or ammonia, which can evaporate from the feed water simultaneously with the vapor in the evaporation chamber and thus can end the contamination of the purified water produced by condensing the gas. These species can be removed in one or more deaerators Self-sufficient water separation in 15, and these degassers can be packed towers, towers with multiple discrete plates, one of the stages in a multi-stage evaporator, empty towers with nozzles, or any other container that further brings the liquid flow into contact with the gas flow. The water to be treated 95 is fed into the container at one location, and the gas flow 100 is fed into the container at the same or another location. The gas can be water vapor (steam), air, nitrogen, argon, a mixture of these gases, or any other non-condensable gas condensed from the product water downstream of the degasser in the evaporation chamber. The feed water and the gas are in contact at least for a part of their paths through the degassing chamber. The degasser has an outlet for the gas 105 mixture, which contains the species removed from the self-sufficient water, and an outlet for the degassed feed water 75. The feed water 75, after undergoing any combination of the above-mentioned pre-treatment, degassing, and pre-heating steps or without any prior steps, can be transferred to one or more evaporation chambers 90A , 90B , 90C. The evaporation chamber 90A, 90B, 90C can be a closed container made of metal, metal alloy, composite, ceramic, polymer, or a combination thereof (such as a metal alloy container with a polymer lining). The evaporation chamber 90A, 90B, 90C can include heat transfer means 110 , such as heat pipes, thermosyphons, hot plates, rods, or a combination thereof. The heat transfer means 110 transfers the energy from an external source 60 to the intermediate concentrate 70, and the energy causes the water to evaporate (a part of the energy can be used to heat the feed water to the boiling point at the operating pressure of the container, and the other part corresponding to the latent heat of evaporation of the feed water can be used to boil the water). The external energy source 60 can be the steam condensed on the hot end of the heat transfer means 110. The steam can come from another evaporation chamber or from an external source. The evaporation chamber 90A, 90B, 90C can contain one or more demisters 30, such as a sieve, a mesh, a baffle, a vortex generator, or a combination thereof. The demister separates droplets from the feed water by the steam released due to evaporation. These droplets contain impurities present in the feed water, and if they are not separated, they will transfer these impurities to the purified water distilled by the evaporation chamber. The droplets typically return to the boiling concentrate pool by gravity after being separated from the steam. Alternatively, they can be collected in an individual stream in the system. The feed water and / or the concentrate are transferred through a series of evaporation chambers 90A, 90B, 90C, and the concentration of dissolved species in the water increases due to water evaporation at each stage. The final concentrate 55 stream is obtained from the last evaporation chamber. Alternatively, the feed water 45 can be supplied in parallel to several or all of the evaporation chambers 90A, 90B, 90C, and the final concentrate 55 can be obtained from several or all of the evaporation chambers. The system can have one or more condensation chambers 35A, 35B, 35C. In one configuration, steam is fed into the condensation chambers 35A, 35B, 35C, and it condenses on the inner surface, including the surface of the heat transfer device 110 (such as heat pipes and other devices listed in the description of the evaporation chamber). The latent heat of vaporization and to a lesser extent some sensible heat from the steam are transferred into the heat transfer device and carried through it to one or more of the evaporation chambers. The condensation chambers 35A, 35B, 35C can be containers made of the same materials as those listed for the evaporation chambers 90A, 90B, 90C. In some configurations, the condensation chambers 35A, 35B, 35C can be adjacent to the evaporation chambers 90A, 90B, 90C. In some configurations, the condensation chambers 35A, 35B, 35C and the evaporation chamber 90A, 90B, 90C may share one or more of the container walls. For example, a pair of evaporation chambers and condensation chambers can be part of the same container and are separated by a perforated plate 115, so that part of these devices is in the condensation chamber and part is in the evaporation chamber, but proper sealing will prevent liquid or gas transfer between the chambers. As another example, multiple evaporation chambers and condensation chambers share a wall and are vertically stacked in a tower or are horizontally adjacent. The system may have the feature of adding in-situ cleaning solution 90A, 90B, 90C. Adding in-situ cleaning solution 120. Adding in-situ cleaning solution 120 can be achieved by pumping it directly into the evaporation chamber 90A, 90B, 90C or by pumping it into the pipeline that introduces the intermediate concentrate 70 into the evaporation chamber 90A, 90B, 90C. Due to the in-situ cleaning procedure, scale debris suspension in the evaporation chamber 90A, 90B, 90C is suspended in the aqueous solution. Small debris can be achieved from the intermediate concentrate 70 through several stages. The larger settled debris can be collected at the bottom of the evaporation chamber 90A, 90B, 90C and removed from the container using a standard valve designed for this purpose in a manner similar to that in a sedimentation tank in a wastewater treatment facility. Alternatively, filters can be used to separate solids between stages. The system may have pipes for carrying fluids into the system, carrying fluids out of the system, or carrying fluids between different parts of the system. Fluids can be moved by the action of pumps, hydrostatic pressure, or the pressure difference generated by boiling aqueous solutions at different temperatures. For example, feed water 45 is pumped to the pretreatment step, then pumped into the preheater, then pumped into the degasser, then pumped into an evaporator, then passed through a series of evaporators, and finally leaves the system via the heat recovery unit. For example, steam is supplied as the energy source for evaporation to the first condensation chamber, the steam generated in the adjacent evaporation chamber is transferred to another condensation chamber, and this is repeated through multiple sets of condensers and evaporators to reuse the energy multiple times, and purified water is obtained when the steam condenses into liquid water. For example, the energy in the first or other condensation chamber is provided by a heat fluid, hot gas, electric heater, combustion of fuel, chemical reaction, or another energy source. The system can have multiple sensors, including temperature sensors, pressure sensors, level sensors, flow sensors, conductivity probes, ion-selective electrodes, colorimetric sensors, spectroscopic sensors, weighing scales, viscosity sensors, and other typical sensors in chemical equipment. The system can have manually or automatically operated valves and pumps. The system can have sampling orifices. The system can have a control unit that operates pumps, operates valves, turns on or off the power of the devices in the system and / or sends an alarm to the operator. The system can automatically record data. In a typical setup, the evaporation chamber 90A, 90B, The temperature in 90C can be in the range of 40 - 200 °C. For example, the temperature can be 50 - 120 °C, 60 - 120 °C, 70 - 120 °C, 100 - 200 °C, 100 - 180 °C, 100 - 160 °C, 100 - 140 °C, 100 - 120 °C, 100 - 110 °C, or approximately 70 °C, 80 °C, 90 °C, 100 °C, 105 °C, 110 °C, 120 °C, 140 °C, 160 °C, 180 °C, 200 °C. The evaporation chamber 90A, 90B, The pressure in 90C can be in the range of 7000 - 1.6×10 6 Pa. For example, the pressure can be 7000 - 105000 Pa, 50000 - 105000 Pa, 100000 - 1.6×10 6 Pa, 100000 - 1×10 6 Pa, 100000 - 800000 Pa, 100000 - 600000 Pa, 100000 - 400000 Pa, 100000 - 200000 Pa, or approximately 7000 Pa, 50000 Pa, 100000 Pa, 200000 Pa, 400000 Pa, 600000 Pa, 800000 Pa, 1×10 6 Pa or 1.6×10 6 Pa. Feed water The concentration of impurities in 45 can be in the range of 50 - 250000 mg / L. For example, the concentration can be concentrated to 50 - 150000 mg / L, 50 - 50000 mg / L, 500 - 20000 mg / L, or approximately 50 mg / L, 500 mg / L, 5000 mg / L, 10000 mg / L, 20000 mg / L, 50000 mg / L, 100000 mg / L, 150000 mg / L, 200000 mg / L, 250000 mg / L or 300000 mg / L. Degassed feed water The concentration of volatile species in 75 can be in the range of 0.01 - 100 mg / L. For example, the concentration can be 0.1 - 50 mg / L, 1 - 50 mg / L, 1 - 10 mg, or approximately 1 mg / L, 5 mg / L, 10 mg / L, 20 mg / L, 30 mg / L, 40 mg / L, 50 mg / L. Final concentrate The concentration in 55 can be in the range of 500 - 750000 mg / L. For example, the concentration can be concentrated to 5000 - 750000 mg / L, 25000 - 500000 mg / L, 50000 - 350000 mg / L, 100000 - 350000 mg / L, or approximately 50000 mg / L, 100000 mg / L, 150000 mg / L, 200000 mg / L, 250000 mg / L, 300000 mg / L, 350000 mg / L, 500000 mg / L. Purified water The concentration in 65 can be in the range of 0.01 - 100 mg / L. For example, the concentration can be concentrated to 0.1 - 50 mg / L, 1 - 50 mg / L, 1 - 20 mg / L, 1 - 10 mg / L, or approximately 0.1 mg / L, 1 mg / L, 5 mg / L, 10 mg / L, 20 mg / L, 30 mg / L, 40 mg / L, 50 mg / L. Evaporation chamber 90A, 90B, 90C and condensation chamber 35A, 35B, The number of 35C can be in the range of 1 - 20. For example, the number can be 1 - 10, 1 - 8, 1 - 6, 1 - 4 or approximately 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. Feed water The flow rate of 113 can range from 0.5 to 10000 L / min. For example, the flow rate can be 100 - 10000 L / min, 100 - 1000 L / min, or approximately 100 L / min, 1000 L / min, 5000 L / min, 1000 L / min. The recovery rate (the percentage of the feed water recovered in the form of purified water) can range from 10 - Ca++. For example, the recovery rate can be 50 - 99%, 75 - 99%, 80 - 99%, 90 - 99% or approximately 50%, 60%, 70%, 80%, 90%, 95%, 99%. The temperature difference between the condensation chamber and the evaporation chamber (along the heat transfer device) can range from 2 to 15 °C. For example, the temperature difference can be 2 - 10 °C, 2 - 6 °C, 2 - 4 °C or approximately 2 °C, 3 °C, 4 °C, 5 °C, 6 °C, 7 °C, 8 °C, 9 °C, 10 °C. Demister The pressure drop at 30 can range from 100 to 20000 Pa. For example, the pressure drop can be 100 - 5000 Pa, 100 - 1000 Pa or approximately 100 Pa, 250 Pa, 500 Pa, 1000 Pa, 2000 Pa, 5000 Pa. The surface cleaning frequency of the heat transfer device can range from 1 to 365 days or longer. For example, the frequency can be 1 - 180 days, 1 - 120 days, 1 - 90 days, 1 - 60 days, 1 - 30 days, 1 - 15 days, 1 - 7 days, 1 - 3 days or approximately 1 day, 2 days, 3 days, 4 days, 7 days, 15 days, 30 days, 60 days, 90 days, 180 days, 365 days. Figure 3 shows a schematic diagram of a desalination system or a concentration system with two stages, where one stage is defined as an evaporation chamber or a preheater and a condensation chamber connected by a heat transfer device (such as a heat pipe and its analogs), or defined as an energy input container and an evaporation chamber. In this embodiment, the evaporation chamber 20 does not share any walls with the condensation chamber. The embodiment also does not have a perforated plate containing a heat pipe as part of the stage. Heat pipe 25 are individually installed on the top of the condensation chamber 35 and the bottom of the evaporation chamber 20. In the embodiment illustrated in Figure 3, the pump 125 moves the preheated feed water 95 and the intermediate concentrate 70 from the evaporation chamber to the next one. Also in this embodiment, the demister 30 is located inside the evaporation chamber 20. In other embodiments, the demister can be located outside the evaporation chamber or can be eliminated together. The purified water 65 flowing from the condensation chamber is combined together. Its flow rate is controlled by a valve 130 Control. FIG. 4 shows an embodiment for stage 90 of a water purification or feed water concentration system. In this embodiment, the intermediate concentrate 70 from the evaporation chamber is moved between the chambers using a pump 125. However, the purified water 65 leaves each condensation chamber individually. The demister of this embodiment 30 consists of a tortuous path generated by baffles 135. FIG. 5 shows an embodiment having five stages. The feed water 45 is pumped 125 to the preheater 10. The steam from the evaporation chamber is used as the stripping gas 15 in the degasser 100. The intermediate concentrate is pumped between the stages. The purified water leaves each evaporation chamber individually. FIG. 6 shows a schematic diagram of a two (2) water production stage system, where the purified water 65B from the hotter condensation chamber 35B is fed into the colder condensation chamber 35A to capture the heat in the purified water before it leaves the system as the total purified water flow 65A. In this embodiment, the system is driven by steam 140 from a steam generator 150. The condensate from the energy input vessel 40 is returned to the steam generator to be reused as boiler feed. FIG. 7 shows a perforated plate 115, a heat pipe or other phase change heat transfer device installed to the perforated plate via a heat pipe mounting hole 160 (see those devices listed previously). The plate also forms the wall between the condensation chamber and the evaporation in the configuration where the two chambers are connected together. FIG. 8 shows the use of a downcomer 165 in a multi-stage system to transfer the intermediate concentrate 70 from one evaporation chamber to the next evaporation chamber 70 Example of the 20-stage. The downcomer relies on gravity to make the intermediate concentrate flow from one chamber to the next. To make the flow overcome the pressure difference between the two evaporation chambers, the chamber supplying the intermediate concentrate must be raised relative to the chamber receiving the concentrate. When using gravity as the driving force for the intermediate concentrate, the previous evaporation chamber of sufficient height will generate a hydraulic overpressure of several inches of water, sufficient to maintain a boiling temperature usually 2-25 °C higher than the previous evaporation chamber, thus ensuring effective heat transfer between the individual distillation stages. Figure 8 also shows the demister. 30 , steam from the lower evaporation chamber 50 , the condensation chamber 35 and the perforated plate 115. The outer shell Figure 9 illustrates an example including evaporation chambers arranged in a vertically stacked configuration 20A, 20B, 20C and 20D and the condensation chamber 35A, 35B, 35C thus providing a heat source at the bottom of the stack, providing a plurality of demisters 30 to remove contaminated fog particles from each evaporation chamber, providing a single heat pipe or a plurality of heat pipes 25 to recover heat from each condensation chamber and transfer such heat to the upper evaporation chamber, and providing an outlet to remove the final concentrate from the last evaporation chamber 20A 55. In such embodiments, all evaporation chambers, condensation chambers, and preheaters are enclosed in the outer shell 170, and the individual chambers are separated by plates, some of which are perforated plates 115 to accommodate the heat pipes 25 to pass through. In the embodiment of Figure 9, the system is in a "cocurrent" configuration, where the feed water 45 enters the system in the hottest evaporation chamber 20D, and proceeds to the coldest evaporation chamber 20A. The pressure difference between adjacent evaporation chambers drives the intermediate concentrate from one evaporation chamber to the next. The flow rate is controlled by a valve 130. The vortex-type demister 30 is located in the evaporation chambers 20A, 20B, 20C and 20D. The purified water 65 leave each evaporation chamber individually. By means of a gas or oil burner 175 supplies the energy of the system to the energy input vessel 40. The chamber at the top of the stack 190 captures the steam from the top evaporation chamber 20A 50, and feeds it into an external condenser (not shown in the figure). Figure 10 shows an embodiment similar to Figure 9, but in which the concentrate 70 is in a "countercurrent" configuration. The pump 125 drives the intermediate concentrate 70 from the coldest evaporation chamber through the other evaporation chambers 20B and 20C, to the hottest evaporation chamber 20D, and the purified water 65 is fed back into the system to capture its energy. Its flow rate is controlled by a valve 130. The energy in the form of steam is supplied to the energy input vessel via a steam ejector 180 40. For systems of certain sizes, these shell-less embodiments provide a cost advantage in manufacturing and offer a simpler configuration that minimizes heat loss. Pretreatment System The pretreatment system can be used to separate scale-forming impurities from the water to be treated or to inhibit scale formation on the inner surfaces of components downstream of the pretreatment system. The pretreatment system can include water softening by ion exchange resins, precipitation (by adding chemicals or by adjusting the pH value), filtration, coagulation, sedimentation, centrifugation, or a combination of these methods. After pretreatment, the feed water is transferred to the next part of the system by the action of a pump, by hydrostatic pressure, or by internal pressure associated with a higher temperature section. In some embodiments, no pretreatment system is used. These embodiments are suitable for applications where the feed water does not contain scale-forming impurities or where the overall purification or concentration system operates at a temperature regime that mediates scale formation. Pretreatment Details One embodiment of the present invention provides a method for removing scale-forming compounds from tap water, contaminated aqueous solutions, seawater, produced water, and physiological saline, concentrates, and other contaminated water (such as contaminated water generated by urban, agricultural / farming, mining, and other industrial processes and activities), which involves initially removing magnesium ions by precipitating magnesium hydroxide (Mg(OH)2) at a high pH value, followed by removing the precipitate by sedimentation or filtration. Generally, Mg(OH)2 precipitates at a high pH value (about 11.0), but in many cases magnesium hydroxide precipitates at a low pH value. After the precipitation of Mg(OH)2, carbonate ions are added in the form of bubbling CO2 by adding a soluble carbonate or bicarbonate whose amount is subsequently adjusted to precipitate calcium, barium, and other divalent cations as carbonates by adjusting the pH value to about 10.2 or greater. This process has the net effect of permanently chelating CO2 from the atmosphere and then removing the precipitate by sedimentation or filtration. The detailed description of this pretreatment embodiment follows the flowchart of FIG. 11. In FIG. 11, the filtered and degreased contaminated water 855 enters the pretreatment system via a line booster pump that delivers the incoming water to the mixer-settler vessel 865A. The pH value of the vessel 865A is maintained at about 11 by the continuous addition of an alkali metal additive in the form of sodium hydroxide, calcium hydroxide, or a similar chemical. The control of the pH value in the vessel 865A is achieved via a metering pump 870, which delivers the caustic solution from the storage tank 875 through a variable valve 880A. The precipitated Mg(OH)2 slurry in the vessel 865A settles and exits near the bottom and is filtered in the filter 885 and leaves near the bottom, and in the filter Continuous filtration in 700A thus produces a magnesium hydroxide filter cake 890. In the vessel After Mg(OH)2 precipitation in 865A, the clarified solution exits near the top and flows into a static mixer 895A, in which it is mixed with additional clarified filtrate from filter 700A and pump 125A and a source of carbonate ions, which can be pressurized CO2 gas from storage tank 900 or a solution of a soluble carbonate or bicarbonate. The aqueous solution then flows into a second static mixer 895B, in which additional caustic or alkali metal chemical is added from variable valve 870A to adjust the pH to about 10.2, at which point most divalent cations in the solution precipitate as insoluble carbonates. The precipitate slurry then enters a mixer-settler 865B, in which the insoluble carbonates settle and flow into a filter 700B, in which a second filter cake is removed 905. The filtrate from filter 700B enters a pump 125B, which feeds into a variable valve 880B, which allows a portion of the detergent water product 910 is recycled back into the carbonation cycle. In another aspect, especially when the feed water contains excessive carbonate or bicarbonate ions, calcium or magnesium can be added to provide the requirements for carbonate precipitation. Alternatively, calcium and magnesium can replace other divalent cations such as barium, cadmium, cobalt, iron, lead, manganese, nickel, strontium, or zinc, which have low solubility products in the form of carbonates. In another aspect, calcium or magnesium additives replace trivalent cations such as aluminum or neodymium, which have solubility products in the form of carbonates or hydroxides. In another aspect, CO2 bubbling is replaced by adding soluble bicarbonate ions such as sodium bicarbonate, potassium bicarbonate, or ammonium bicarbonate. In another aspect, carbonate and scale precipitates are removed by means other than sedimentation or filtration such as centrifugation. In another aspect, CO2 is permanently chelated from the atmosphere and achieved in conventional desalination systems such as MSF devices, MED devices, vapor compression evaporators, membrane distillation systems, reverse osmosis, forward osmosis, and other desalination systems. In another aspect, scale-forming salts are permanently removed from conventional desalination systems. In another aspect, tap water, seawater, gray water from residential systems, agricultural water, industrial process water, municipal water, or well water containing unpleasant hard water components such as calcium or magnesium are descaled in a water purification system. In another aspect, valuable scale-forming salts such as magnesium, barium, and other salts are recovered. In another aspect, scale-forming compounds precipitate in a non-adherent, easily filterable, or sedimentable solid form and are ultimately removed. In another aspect, CO2 is emitted from a power plant and permanently chelated similar to flue gas. In another aspect, scale-forming compounds precipitate and are removed sequentially so that they can be utilized and reused in downstream industrial processes. Another embodiment of the present invention provides a method for removing scale-forming compounds from an aqueous solution, involving: adding at least one ion in an amount sufficient to precipitate a first scale-forming compound at an alkaline pH value to the solution; adjusting the pH value of the solution to an alkaline pH value, thereby precipitating the first scale-forming compound; removing the first scale-forming compound from the solution; heating the solution to a temperature sufficient to precipitate a second scale-forming compound from the solution; and removing the second scale-forming compound from the solution. In another aspect, the ion is selected from the group including carbonate ions and divalent cations. In another aspect, the carbonate ion is HCO3-. In another aspect, the divalent cation is selected from the group including Ca2+ and Mg2+. In another aspect, the amount is sufficient to replace the divalent cation selected from the group including the following in the first scale-forming compound: barium, cadmium, cobalt, iron, lead, manganese, nickel, strontium, and zinc. In another aspect, the amount is sufficient to replace the trivalent cation selected from the group including aluminum and neodymium in the first scale-forming compound. In another aspect, adding at least one ion includes bubbling the solution with CO2 gas. In another aspect, the CO2 is atmospheric CO2.In another aspect, adding at least one ion comprises adding soluble bicarbonate ions selected from the group consisting of sodium bicarbonate, potassium bicarbonate, and ammonium bicarbonate to the solution. In another aspect, adding at least one ion comprises adding a compound selected from the group consisting of CaO, Ca(OH)2, Mg(OH)2, and MgO to the solution. In another aspect, the alkaline pH value is a pH value of approximately 9.2 or greater. In another aspect, the first scale-forming compound is selected from the group consisting of CaCO3 and MgCO3. In another aspect, adjusting the pH value of the solution comprises adding a compound selected from the group consisting of CaO and NaOH to the solution. In another aspect, removing the first scale-forming compound comprises at least one of filtration, sedimentation, and centrifugation. Avoiding scale-forming compounds An embodiment of the present invention provides a method for obtaining scale-forming compounds, involving: providing an aqueous solution; adding an alkali metal chemical in an amount sufficient to precipitate the first scale-forming compound at an alkaline pH value; adjusting the pH value of the solution to an alkaline pH value, thereby precipitating the first scale-forming compound; removing the first scale-forming compound from the solution; adding carbonate ions while maintaining an alkaline pH value sufficient to precipitate the second scale-forming compound from the solution; removing the second scale-forming compound from the solution; recovering the first scale-forming compound; and recovering the second scale-forming compound. In another aspect, the first and second scale-forming compounds are selected from the group of compounds listed in Table 3. CO. 2Chelation One embodiment of the present invention provides a method for chelating atmospheric CO2, involving: providing an aqueous solution containing at least one ion capable of forming a CO2 chelating compound in the presence of carbonate ions; adding carbonate ions in an amount sufficient to precipitate the CO2 chelating compound at an alkaline pH value to the solution; adjusting the pH value of the solution to an alkaline pH value, thereby precipitating the CO2 chelating compound; and removing the CO2 chelating compound from the solution; wherein adding carbonate ions includes adding atmospheric or concentrated CO2 (such as from combustion flue gas) to the solution, and wherein CO2 is chelated as a CO2 chelating compound. Settler The system may further include a settler capable of removing sediment from the inlet feed water, thereby avoiding premature fouling of the system by such sediment. Various types of settlers are known in the art and can be selected for use with the system of the present invention. Similarly, to minimize user intervention and the need for cleaning, the settler itself may have self-cleaning features. For example, the settler may have an alternating sand filter or a rotary screen, where the rotation from a fouled screen to a fresh screen can be driven by a water pressure difference on the device such that when the screen reaches a certain saturation point with respect to the accumulated sediment, it is switched to a screen with unfouled sediment. In some embodiments, the fouled screen or sand filter may be placed in the water flow path such that water flows through the sand filter or screen in a direction opposite to the original flow on the screen, thus moving the sediment to a waste path or discharge port. Therefore, the systems disclosed herein encompass the use of conventional as well as self-cleaning settlers. Additionally, the system may include conventional pretreatment steps such as flocculation, followed by sedimentation (such as in a clarifier tank), sterilization by chlorination, UV, or other means, and pH adjustment by adding acid or base. Preheater The pretreated or untreated feed water can be transferred to one or more preheater units. The preheater units transfer heat from the process stream to the feed water. The preheater units may include heat exchangers, hot plates, heat pipes, pipes, or rods. The process stream serving as the heat source in the preheater can be steam generated in an evaporation chamber, steam generated from flashed pressurized water within a process vessel, steam from an external supply, purified water, concentrate, or a combination of such substances. In a typical setup, the feed water is preheated to a temperature between the starting temperature of the feed water and the boiling point of the feed water to the first evaporation chamber (including the boiling point elevation due to dissolved solids in the feed water). The feed water is introduced into the preheater, heated until the desired temperature is reached, and exits the preheater via a downcomer, a conduit with a valve, or a pump connecting to a deaerator or an evaporation chamber (if deaeration is not required). The preheating function can be carried out in many different ways, with the limitation that the result is that the feed water, physiological saline, or seawater flowing into the system reaches the deaerator at a temperature of approximately less than 50°C to 90°C or greater. Therefore, the preheating function can be implemented in many different forms, including, for example, cylindrical tanks, rectangular tanks, or any type of different configurations with a design allowing a high surface area to internal volume ratio and the like.In some embodiments, as illustrated by FIG. 12, the preheater is heated by a plurality of heat pipes that penetrate the preheater from the bottom. The heat pipes transfer the condensation heat of the steam entering the condensation chamber 50 to the introduced feed water 45. When the feed water 45 enters the preheater inlet 155, it is gradually heated by the heat pipes 25 to a temperature close to the boiling point. When the feed water reaches a temperature close to the boiling point, it exits as preheated feed water 95 via a pipe 185 exits the preheater. The size and configuration of the preheater are such that sufficient residence time is allowed to raise the temperature of the water in the preheater to about less than 50°C to 90°C or greater. Depending on the scale in the system and the ability of the system to transport water, the preheating function can benefit from materials and configurations that allow for efficient heat exchange. Alternatively, in some embodiments, the durability of the structure, space considerations, ease of maintenance, availability or cost of materials, and other considerations can all affect the design choices for this aspect of the present invention. In some embodiments, the preheater can use conventional heat exchangers, such as shell and tube configurations. Deaerator The feed water to be treated may include unwanted chemical species having a relatively low vapor pressure, such as volatile organic compounds, other organic liquids, or ammonia. These unwanted species can evaporate simultaneously with the vapor in the evaporation chamber and can thus end the contamination of the purified water produced by condensing the vapor. These species can be separated from the feed water by passing the feed water through one or more deaeration vessels. The deaeration vessel can include a packed tower, a tower with multiple discrete plates, one of the stages in a multi-stage evaporator, an empty tower with nozzles, or any other vessel that brings the liquid flow into contact with the gas flow. The feed water to be deaerated is fed into the vessel at one location, and the gas stream is fed into the vessel at the same or another location. The gas can be water vapor (steam), air, nitrogen, argon, methane, a mixture of these gases, or any other non-condensable gas that is condensed from the purified water downstream of the deaerator in the evaporation chamber. The feed water and the gas are in contact at least for a portion of their paths through the deaeration chamber. During their contact, the gas strips volatiles, organics, ammonia, and dissolved gases from the feed water. The deaerator has an outlet for the mixture of gases that contains the species removed from the feed water, and an outlet for the deaerated feed water. The deaerator can be generally vertically oriented, having an upper end and a lower end. In one embodiment, steam from the nearest evaporation chamber (or other steam source) can enter the deaerator near the lower end, can strip the feed water with unwanted compounds, and can leave the deaerator near the upper end together with those compounds. Other orientations of the deaerator are also possible, such as a horizontal configuration, a vacuum deaerator, or a conical spray type configuration. FIG. 13 shows a schematic diagram of an embodiment of the deaerator. In this embodiment, the preheated feed water 95 enters the deaerator at the top of 15. The gas stream 100 enters the deaerator near the bottom. The waste gas 105 leaves near the top. The deaerated feed water 75 exits near the bottom. The deaerator may include a matrix adapted to facilitate water and steam mixing by subjecting the inlet feed water to a countercurrent stripping of the gas with respect to the reverse flow of the inlet feed water having substantially all of the organic matter, volatiles, and gases. The matrix may include substantially spherical particles. However, the matrix may also include non-spherical particles, rings, other mixing elements, trays, and the like. The matrix may include particles sized to allow for uniform packing within the deaerator. The matrix may also include particles having unique sizes, and the particles may be arranged in a size gradient within the deaerator to improve the interaction between the gas and the liquid. Non-condensable dissolved gases may also be removed in the first evaporation chamber using available devices designed for non-condensable gas removal. FIG. 14 shows a cross-section of an embodiment of the deaerator. The preheated feed water 95 enters the deaerator at the top of 15 and is dispersed by a spray head The preheated feed water travels through a particle-packed column including larger particles 195, medium-sized particles 200, and smaller particles 205. At the same time, a gas stream stripping volatiles and organic matter 100 enters from near the bottom of the deaerator 15. The preheated feed water 95 flows through the particles 195, 200, and 205, mixing with the gas stream stripping volatiles and organic matter from the preheated feed water 95. The deaerated feed water 75 exits the deaerator near the bottom. Waste gases including volatiles and organic matter 105 exits the degasser near the top. Feed water can be transferred to one or more evaporation chambers after undergoing any combination of the above-mentioned pretreatment, degassing, and preheating steps. Alternatively, the feed water can be transferred to one or more evaporation chambers without undergoing any prior steps. The evaporation chamber can be a closed container made of metal, metal alloy, composite, ceramic, polymer, or combinations thereof (such as a metal alloy container with a polymer lining). The evaporation chamber can include heat transfer devices such as heat pipes, thermosyphons, annular heat pipes, hot plates, rods, or combinations thereof. The heat transfer devices transfer energy from an external source or from a condensation chamber to the feed water. This energy evaporates the feed water. A portion of the energy is used to heat the feed water to the boiling point at the operating pressure of the container, and a portion corresponding to the latent heat of evaporation of the feed water is used to boil the water. The evaporation chamber can include a cylindrical or rectangular reservoir with a porous bottom that houses multiple heat pipes or other heat transfer devices. The evaporation chamber can also include an outlet or downcomer or both for the intermediate concentrate, with or without a pump, that is in fluid communication with a subsequent evaporation chamber. The intermediate concentrate outlet can be located in the sidewall of the chamber or at the center or off-center in the bottom of the chamber. Residence time in the evaporation chamber Based on the nature of the inlet feed water and the desired system performance, the residence time of water in the evaporation chamber can vary within a range. The suitable range is determined by various factors, including whether biological contaminants are present in the feed water. Effective removal of biological contaminants may require different amounts of time exposed to high temperatures in the evaporation chamber. Some biological contaminants are affected by high heat more rapidly than others. In multiple embodiments, a residence time as short as 10 minutes is sufficient to kill most biological contaminants. In other embodiments, longer residence times may be required to more thoroughly eliminate a broader spectrum of biological contaminants. In situations where biological contaminants are not a problem, shorter dwell times are appropriate. The upper end of the residence time range in the evaporation chamber is typically specified by efficiency considerations related to the energy required to maintain a selected volume of water at the boiling temperature compared to the desired production rate of the product water or concentrate solution. Thus, the residence time in the evaporation chamber can be as little as approximately the minimum time required for the water to reach the boiling point and be released as steam, and time points beneficial for removing biological contaminants are such as 10, 15, 20, 25, 30, 35, 40, 45 minutes and similar times. Additionally, in some embodiments, higher residence times can be selected, such as 50, 60, 70, 80, and 90 minutes or higher. As shown in FIGS. 15 and 16, the introduced feed water 45 flows into the evaporation chamber by gravity, by different chamber pressures, and / or by pumping 20. FIG. 15 shows the degasser 20 on top of the evaporation chamber 15. If the feed water has not been degassed, then this preheated feed water 80 first flows into the degasser 15, and the configuration therein can be used for the first evaporation chamber. FIG. 16 shows the feed water 45. Preheated feed water 80 or intermediate concentrate 70 flows into the evaporation chamber configuration. This configuration is used in the evaporation chamber that appears after degassing or does not require degassing. The demisted steam from the previous evaporation chamber 50A condenses on the heat pipe 25, and the heat pipe transfers the condensation heat to the intermediate concentrate in the evaporation chamber. Demisted steam 50B from the demister 30 flows into the next condensation chamber. The waste stream from the demister 30 220 can flow into the next evaporation chamber together with the intermediate concentrate. Depending on the required throughput of the system and other design choices based on factors affecting the system design, the evaporation chamber can have substantially any size and configuration. For example, the evaporation chamber can have a capacity in the range of less than 10 gallons to greater than 100,000 gallons or more. Since the system of the present invention is fully scalable, the size of the evaporation chamber can be variable and selected as needed. Similarly, the configuration of the evaporation chamber can be changed as needed. For example, the evaporation chamber can be cylindrical, spherical, rectangular, or any other shape. In a typical embodiment, the evaporation chamber 20 is cylindrical, including one or more heat pipes installed on the perforated plate 115 and extending into the evaporation chamber 25, having an intermediate concentrate 70 for transporting the intermediate concentrate 70 to the next evaporation chamber 215, and having a demister 30 installed on the top of the evaporation chamber. In this configuration, the degasser waste stream carrying the volatile components from the degasser 105 is shown close to the top of the degasser 15. Since the operation of the purification system is continuous, the feed water is partially concentrated by boiling, and the degree of concentration in the evaporation chamber 20 is determined by the number of distillation stages and the boiling rate of each stage. In a simple example, if seawater is used in two distillation stages, the salinity in the evaporation chamber can be maintained at approximately half of the value of the waste concentrate to be discarded or about 12%. In another example, if three distillation stages are used, the evaporation chamber The salinity in 20 reaches about one-third of the final concentrate concentration of about 23%, or the maximum solubility limit of the solutes in the specific feed water being treated. As pointed out above, because the evaporation chamber can have significantly different boiling rates depending on, for example, the number of heat pipes it contains, or the temperature difference between the condensation chamber and the evaporation chamber, or the feed water flow rate, etc., these concentration numbers are only rough estimates to merely illustrate the concept. They are just two examples of many different possible intermediate concentrate concentrations. In one embodiment, the evaporation chamber is discharged only by gravity via a downcomer. In other embodiments, the discharge of the evaporation chamber is driven by a pumping device. The continuous discharge of the evaporation chamber maintains a constant liquid level of the boiling fluid in the chamber, and such continuous discharge also avoids the precipitation of sediment, salts, and other particulates in the evaporation chamber. Demister The evaporation chamber may include one or more demisters, including screens, meshes, baffles, vortexers, or combinations thereof. The demister prevents droplets that may be present in the steam generated in the evaporation chamber from being carried with the steam into the corresponding condensation chamber, where impurities in the droplets would contaminate the purified water produced by condensing the steam. After being separated from the steam by the demister, the droplets typically return to the boiling feed water pool by gravity. Alternatively, they can be collected in individual streams in the system. The demister can be disposed close to the upper surface of the evaporation chamber. The steam from the evaporation chamber can enter the demister under pressure. The demister then separates small mist-like droplets from the steam flow and returns the droplets to the evaporation chamber. The steam can also condense into droplets on the lower surface of 250, as shown in FIG. 17. Such droplets 235 can migrate laterally and can follow the steam 245 flow into the demister device 30. In one embodiment, one or more metal grooves 230 prevent such droplets from migrating and contaminating the steam flow. Additionally, a protective baffle 240 can also provide a barrier for the mist-like particles carried by the steam. Finally, a mesh-lined demister 225 can be added to the configuration to capture any final mist. Other types of demisters are those that operate based on different densities using cyclones to separate the steam from the mist. The vortexer operates based on the principle of moving a fluid or gas in a radial motion at a high speed, applying a centrifugal force to the components of the fluid or gas. Conventional vortexers have a conical section, which can contribute to angular acceleration in some cases. The key parameters that control the separation efficiency of the vortexer are the size of the steam inlet, the sizes of the two outlets (for the clean steam and the mist carrying contaminants), and the pressure difference between the inlet point and the outlet point. As shown in FIGS. 18 and 19, the demister can be disposed inside, adjacent to, or on the evaporation chamber 20, allowing the steam from the chamber to pass through the inlet orifice 260 enters the demister. The steam entering the demister through such orifices has an initial velocity that is mainly due to the pressure difference between the evaporation chamber and the demister and the configuration of the orifices. Generally, the pressure difference across the demister is about 0.5 to 10 inches of water column, i.e., about 125 to 2500 Pa. The inlet orifices are generally designed to minimize the resistance to the entry of steam into the vortex. At high velocities, such as in the conical region 265 of the vortex, the clean steam, which is relatively less dense than the mist, migrates towards the center of the vortex machine, while the mist moves towards the periphery. The clean steam outlet 270 located at the center of the vortex provides a point for the clean steam to leave, while the mist outlet 275 located near the bottom of the vortex machine allows the mist flows out of the 220 demister. The clean steam flows into the condensation chamber from the demister, while the mist is guided into the evaporation chamber. In typical operation, the ratio of clean steam to mist is at least about 2:1; more typically 3:1, 4:1, 5:1, or 6:1; preferably 7:1, 8:1, 9:1, or 10:1, and greater than 100:1 or more. The demister can optionally be adjusted based on several factors, including, for example, the position and size of the opening through which the clean steam exits, the pressure differential across the demister, the configuration and size of the demister, and the like. Other information regarding demister design is provided in U.S. Provisional Patent Application No. 60 / 697,107, filed on July 6, 2005, entitled IMPROVED CYCLONE DEMISTER, which is incorporated herein by reference in its entirety. In another aspect, the demister can use separation, for example, by increasing the cross-sectional area of the container or conduit to separate the mist droplets from the clean steam. In another aspect, the evaporation chamber is protected from condensate droplets entering the demister by means of a protective baffle and a metal groove. In another aspect, the ratio of clean steam to mist droplets is greater than about 10:1. In another aspect, the steam quality includes at least one parameter selected from the group consisting of: clean steam purity, the ratio of clean steam to mist droplets, and the total clean steam volume. Condenser The system can have one or more condensation chambers. In a typical configuration, steam is fed into the condensation chamber, where it condenses on the inner surface, including the surface of heat transfer devices (such as heat pipes, annular heat pipes, heat plates, rods, or combinations of such devices). The latent heat of vaporization and some sensible heat from the steam are transferred into the heat transfer devices and carried via them to the concentrate in one or more of the evaporation chambers. The condensation chamber can be a container made of metal, metal alloy, composite, ceramic, polymer, or combination (such as a metal alloy container with a polymer liner) or other materials suitable for handling steam. In some configurations, the condensation chamber can be adjacent to the evaporation chamber. In some configurations, one or more of the container walls can be shared between the condensation chamber and the evaporation chamber. For example, the evaporation chamber and the condensation chamber pair can be part of the same container separated by a plate with heat transfer devices installed. Part of these heat transfer devices will be in the condensation chamber and part will be in the evaporation chamber. Appropriate seals prevent transfer between the liquid or gas chambers. As another example, multiple evaporation chambers and condensation chambers share a wall and are vertically stacked in a tower. In another example, the evaporation chamber and the condensation chamber are horizontally adjacent. The condensation chamber can include vanes that impart circular motion to the steam entering it from the evaporation chamber or an external source. This circular motion will increase the velocity of the steam and direct the steam towards the heat pipes to ensure complete steam condensation. The steam can also be injected into the condensation chamber by means of an open-ended pipe or by means of a steam injection configuration that also increases the steam velocity or directs the steam towards the heat transfer devices or both, to more effectively use the steam. These steam injectors can be introduced through the bottom, side, or top of the condensation chamber.Steam ejectors may also be present that introduce steam from some or all of the above locations. The condensation chamber can be cylindrical, oval, rectangular, or other suitable shapes. Purified water can leave the condensation chamber via the purified water outlet. In a typical embodiment, heat is removed from the condensation chamber by a heat pipe, a thermosyphon, or other phase change heat transfer devices. The transfer of heat from the condensing steam to the inlet feed water by a heat pipe is described in U.S. Provisional Patent Application No. 60 / 727,106, entitled ENERGY-EFFICIENT DISTILLATION SYSTEM, filed on Oct. 14, 2005, and U.S. Patent Application No. 12 / 090,248, also entitled ENERGY-EFFICIENT DISTILLATION SYSTEM, filed on Sep. 9, 2008 and published as U.S. Patent Application Publication No. 2009 / 0218210, the disclosures of which are incorporated herein by reference in their entireties. In the embodiments shown in FIGS. 20 and 21(a), the clean steam enters the condensation chamber from the demister or from the evaporation chamber via a pipe. 285 enters the condensation chamber 35. When the steam enters the condensation chamber, it rotates in a spiral manner that increases the steam velocity or directs the steam towards the heat pipe or both to make the condensation most efficient. The spiral movement of the steam in the condensation chamber is generated by spiral vanes. The condensation heat is removed by a plurality of heat pipes installed such that a part of them extends into the condensation chamber and a part extends into the evaporation chamber or the preheater 25. When the heat is removed by the heat pipes and transferred to the evaporation chamber or the preheater, the steam condenses into purified water, which leaves via the purified water outlet 290. In the embodiment of FIG. 21(b), a plurality of steam ejectors 180 are used to transfer the steam into the spiral configuration of the condensation chamber to further increase the steam velocity and its direction towards the heat pipe 25 or other heat transfer devices in the condensation chamber. Detailed description of the heat pipe FIG. 22 illustrates a conventional heat pipe, which is the principle of operation of a type of heat transfer device used in a typical embodiment. The heat pipe consists of a sealed tube 355 with a partial vacuum that is partially filled with a small volume of a working fluid 350. The working fluid can be water or other fluids with a boiling temperature within the range of the entire system. The pipe is also usually filled with a capillary wick 360 or capillary grooves. The heat source 365 causes the working fluid Energy is provided at one end of the evaporation heat pipe for all or part of 355. The vapor thus immediately generated fills the pipe. Once this working fluid vapor reaches the opposite end of the heat pipe where the temperature is slightly lower, it condenses and provides its energy in the form of the heat of condensation leaving the heat pipe. When the working fluid condenses into a liquid, it is carried back to the starting point by the capillary wick 360 adsorption. In some cases, other forms of wicks or simply gravity provide the required power to carry the liquid back to the starting point. Since by definition the heat of evaporation is equal to the heat of condensation, the heat pipe transfers heat very effectively, with no significant temperature loss except for heat loss through the walls. It should be noted that the thermosyphon operates in the same way but without a wick. Heat pipes of other configurations (annular heat pipes, plate heat pipes, radiators, etc.) also act in a similar manner and can be used as heat transfer devices in embodiments of the present invention. An example of a high-performance heat pipe is shown in FIG. 23. Vibration energy 370 is provided for the heat pipe in the form of mechanical vibration, electromechanical vibration, or high-frequency ultrasonic 25. This vibration is transmitted along the length of the heat pipe and disturbs the vapor or fluid layer adjacent to the heat pipe. The disruption of this layer promotes micro-turbulence in the layer, thus resulting in improved heat transfer. Additionally, a hydrophobic coating 375 is provided on the outside of the heat pipe, especially in the areas where external condensation occurs. The hydrophobic coating can consist of a single layer of stearic acid or a similar hydrocarbon, or it can be a thin hydrophobic chlorofluorocarbon layer. The hydrophobic surface on the outside of the heat pipe minimizes the area required for condensation and evaporation, thus reducing the resistance to heat transfer. The heat transfer resistance is also minimized by using an extremely thin metal foil 380 instead of the solid metal pipe of most heat pipes. The mechanical support of the metal foil must be sufficient to maintain a medium vacuum and is provided by a metal mesh 385, which provides an additional function by increasing the internal surface area required to provide the necessary heat of condensation / evaporation. Improved working fluid distribution is achieved by the wick It is oriented along the axis of the 360-degree heat pipe, so the heat transfer from the heat pipe wall reduces the thermal interference of the condensate. The wick material can be any hydrophilic porous medium that can transfer the working fluid by capillary action, such as metal oxides, some ceramics, surface-treated cellulose materials, and the like. Examples of high-performance heat pipes can include any one, several, or all of the above features. Materials of the structure The materials for the structures of the evaporation chamber, condensation chamber, degasser, demister, preheater, and other containers and pipes can be any materials that resist corrosion in physiological saline, industrial wastewater, chemical substances, or pure water environments. In one embodiment, the evaporation chamber and the preheater are made of titanium or titanium alloys such as Ti-CP1 or Ti-CP2, which are known to resist corrosion by hot physiological saline solutions. Alternatively, stainless steel alloys, nickel alloys, copper alloys, or other corrosion-resistant alloys can be used. Alternatively, conventional carbon steel or other metal alloys can be used when coated with specific chlorofluorocarbon polymers (such as Teflon®) or various polymer materials that resist boiling temperatures and physiological saline or chemical environments. Additionally, metal, ceramic, or metal-ceramic composite coatings, or both, can be deposited on the container walls to prevent their corrosion. The materials of these structures are illustrative and are not intended to limit the scope of the present invention. Those skilled in the art can consider alternative materials and coatings, such as other metals, alloys, and polymers, which are within the spirit of the present invention and are defined by the scope of the present invention. Pipes, flow, and configuration The system can have pipes that carry fluids into the system, out of the system, or between different parts of the system. The fluid can be moved by the action of a pump, hydrostatic pressure, or the pressure difference generated by boiling aqueous solutions at different temperatures. For example, the feed water pump can be drawn into the pretreatment step, then pumped into the degasser, then pumped into the preheater, then pumped into an evaporator, then through a series of evaporators, and finally leave the system via the heat recovery unit. The purified water can be discharged or pumped out from the condensation chamber, or it can be fed from one condensation chamber into another condensation chamber to utilize the energy stored therein due to its high temperature. Control system The entire system can be manually controlled, automatically controlled by the operator using the control panel to input controls, or based on the control system feedback from various sensors during operation. Such controls can include valve settings, feed water flow settings, energy input settings (such as for steam, electricity, heat, or others), etc.Feedback control can be based on, for example, feed water flow rate, feed water quality, feed water temperature, feed water pressure, temperature in one or more evaporation chambers, temperature in one or more condensation chambers, pressure in one or more evaporation chambers, pressure in one or more condensation chambers, feed water content in one or more evaporation chambers, purified water content in one or more condensation chambers, one or more purified water qualities (such as total dissolved solids, conductivity, pH value, temperature, pressure), concentrate quality (such as total dissolved solids, conductivity, pH value, temperature, pressure), one or more purified water flow rates, one or more concentrate flow rates, one or more flow rates between evaporation chambers, flow rates between condensation chambers (steam or purified water or both), amount of purified water in the purified water collection reservoir, amount of concentrate in the final concentrate collection reservoir, time of feed water or concentrate flow, time of no feed water or concentrate flow, pressure difference between evaporation chambers or condensation chambers, temperature difference between evaporation chambers or condensation chambers, pressure or temperature drop through the pipeline, leak detection and the like. In another aspect, the system can include shutdown control. In another aspect, the control system can shut down based on feedback control from the system or from another system that delivers feed water to the system. The shutdown control can be selected from the group consisting of: manual control, leak detector, reservoir capacity control, evaporation chamber capacity control, condensation chamber capacity control, feed water quality, concentrate quality, temperature or pressure sensors or similar control devices. In another aspect, the system can include a flow controller for the feed water entering the system and between the evaporation chambers. The flow controller can include means selected from the group consisting of: pressure regulating factor, pump, solenoid, valve, orifice and the like. In another aspect, the pressure regulating factor can maintain the inlet and vessel pressures between about 0 kPa and 1,000 kPa (0 to 150 psi) or more above the pressure in the vessel into which the feed water is injected. In another aspect, the flow controller can maintain the flow rate between 0.5 and 35,000 gallons per minute or greater. In another aspect, the flow regulating factor is controlled by the control system. Such control can provide an on / off signal to the flow regulating factor, or it can continuously provide a variable flow control signal.In another aspect, the control system can control the feed water flow based on at least one of the following: feed water quality, feed water temperature, feed water pressure, temperature in one or more evaporation chambers, temperature in one or more condensation chambers, pressure in one or more evaporation chambers, pressure in one or more condensation chambers, feed water content in one or more evaporation chambers, purified water content in one or more condensation chambers, one or more purified water qualities (such as total dissolved solids, conductivity, pH value, temperature, pressure), concentrate quality (such as total dissolved solids, conductivity, pH value, temperature, pressure), one or more purified water flow rates, one or more concentrate flow rates, one or more flow rates between evaporation chambers, flow rates between condensation chambers (steam or purified water or both), amount of purified water in the purified water collection reservoir, amount of concentrate in the final concentrate collection reservoir, time of feed water or concentrate flow, time without feed water or concentrate flow, pressure difference between evaporation chambers or condensation chambers, temperature difference between evaporation chambers or condensation chambers, pressure or temperature drop through the pipeline, leakage detection. The control system can allow the entire system to operate continuously or in batches. An example of a control system is shown in FIG. 24. For example, the system can include a human-machine interface (HMI) that can be involved in control and status, operating mode, status level, and alarms. The HMI can be associated with a supervisory control system that can be involved in set points. The supervisory control system can be associated with a microcontroller or a state machine-based computer that can be involved in one or more control elements, water control valves, steam control valves, drain solenoids, and / or heat control valves. The microcontroller or the state machine-based computer can be associated with the desalination machine. The machine and the controller can be involved in sensors, chamber temperature, chamber pressure, water flow rate, water TDS, water content, etc. The microcontroller and the supervisory control system can be involved in status and alarms. Sensors The system can have multiple sensors, including temperature sensors, pressure sensors, level sensors, flow sensors, conductivity probes, ion-selective electrodes, colorimetric sensors, spectroscopic sensors, weight scales, viscosity sensors, and other typical sensors in chemical equipment. The system can have manually or automatically operated valves and pumps. The system can have sampling orifices. The control unit of the system can operate pumps and valves, turn on or off the power of the devices in the system, send alarms to the operator, and provide feedback to the operator about the system status. The control system can also automatically record data. The following discussion is assisted with reference to FIG. 24, which is an example of a control system and operating mode for a water purification or feed water concentration system. The control system for this and other embodiments can be suitable for the specific needs of the current application. In this example, when the main power switch is energized, the control circuit determines the startup procedure and then operates continuously. First, power is delivered to the intake pump, which begins to transfer the feed water to the entire system at a continuous flow rate. User inputs include "start", "pause / hold", stop, and maintenance mode, and the user status can display the operating mode and sensor status via a display, remote terminal, or via the Internet.The sensor inputs include preheater temperature, evaporation chamber temperature, degasser temperature, demister temperature, inlet feed water turbidity (total dissolved solids), purified water turbidity (total dissolved solids), concentrate material (such as total dissolved solids), purified water storage tank level, and leak detection. Upon startup, the temperature sensor at the preheater detects a temperature less than that required for effective degassing, which activates a solenoid valve that diverts all outputs from the condensation chambers to the waste discharge port. At the same time, the same temperature sensor activates an energy input switch, which activates an energy input into an energy input vessel. Depending on which heat source is being used, the input switch can turn on the power to an electric coil, open a fuel supply, open a steam valve, ignite a burner, or open a waste heat supply, or any combination of these actions. When the system reaches a certain temperature, the sensor in the preheater reaches the effective degassing temperature, at which time the control system activates a solenoid valve that closes the discharge of the condensation chambers and allows the collection and ultimate transfer of purified water. The control circuit includes multiple safety features, all of which can shut off the power to the system while activating a warning light or an audible signal. A conductivity sensor located at the purified water outlet continuously monitors the water quality and, if such quality drops below a predetermined point, alarms or shuts down the system. The operating status can include water quality alarms, water quality errors, and operating modes such as startup, normal, maintenance, and shutdown. External system control can be achieved by the source feed water flow or by the evaporation chamber heat. Similarly, in one embodiment, a temperature sensor at the energy input vessel prevents the system from overheating. A conductivity probe located in the waste discharge stream measures the concentration of the waste concentrate and, if such concentration exceeds the solubility limit of the solute, shuts down the system, thus preventing crystallization problems within the system. Similar control systems can be developed for use with a brine / solution concentration system, where the final concentration of the concentrate output provides one of the main control parameters. Phase Description In some embodiments, only one water generation or feed water concentration phase is required. In other embodiments, multiple boiling and condensation phases can be provided, thus providing recycled heat for multiple distillation phases. Each phase can include an evaporation chamber, a demister, a condensation chamber, and multiple heat pipes, all as described above. Other embodiments may not have a demister. Other embodiments may have a single heat pipe. Other embodiments may have different numbers of heat pipes or different types of heat pipes, or a combination of different numbers and different types, in different phases. In another aspect, the system includes a heat pipe for cooling the condensation chamber product. In another aspect, purified water leaves the condensation chamber via the purified water outlet. In another aspect, the concentrate leaves the system via the concentrate outlet. In another aspect, the control system diverts the purified water to the waste discharge port until the system reaches stable operating temperature, pressure, and purified water or concentrate material. Energy Input Vessel To allow energy to enter the system, an energy input vessel is used.The energy supplied to the container can be in the following forms: electrical energy, steam, solar energy, energy from chemical reactions, geothermal energy, molten salts, energy from the combustion of fuels (such as natural gas, oil, or other hydrocarbon fuels), other heat sources, including waste heat from industrial, chemical, power generation, or commercial operations. In another aspect, the energy input to the container further includes an electric heater, a fuel burner, and / or a heat pipe that transfers heat from: electricity, steam, solar energy, chemical reactions, nuclear reactions, geothermal sources, molten salts, waste heat from industrial and other processes, flue gas, solid waste energy, heated heat transfer fluids, microwaves, and / or the combustion of oil, hydrocarbons, biofuels, alcohols, or natural gas, and wherein the energy input container is thermally connected to the evaporation chamber by a heat pipe. Several embodiments are shown in FIG. 25, illustrating various different configurations for providing energy. The energy for distillation is provided by an energy input container disposed adjacent to the evaporation chamber. 40. FIG. 25(a) illustrates the fact that the subject matter of the present invention is energy agnostic. The proposed system for desalination or water concentration can use any form of energy as an energy source 60, including electricity, natural gas, oil or hydrocarbons, steam, flue gas, solar energy, geothermal, chemicals, and chemical reaction energy, waste heat, heat transfer fluids, or other industrial heat sources. FIG. 25(b) illustrates the simplest configuration, which consists of an oil or gas burner 175. Heat is transferred to the adjacent evaporation chamber by heat conduction. FIG. 25(c) depicts an electric heater equipped with a power supply and a resistance heater 390. Heat is transferred to the adjacent evaporation chamber by heat conduction. FIG. 25(d) illustrates the use of a resistance heater 395 surrounded by an insulating sleeve and connected to a power supply 400 and then transferring heat to the evaporation chamber via a heat pipe 25. FIG. 25(e) illustrates the use of a heat pipe 25 to utilize waste heat or other heat sources 405 to transfer heat to the evaporation chamber. FIG. 25(f) illustrates a steam source 140 together with a heat pipe 25 for transferring heat to the evaporation chamber. FIG. 25(g) illustrates a heat transfer fluid 410 together with a heat pipe 25 25 is used together to transfer heat into the evaporation chamber. Exemplary Method In some embodiments, the present invention relates to a method for purifying, desalinating, and / or concentrating feed water. Although this section of the present invention is labeled "Exemplary Method" and is described to describe certain methods of applying the concepts disclosed throughout this document, it is expressly provided that the various methods and steps disclosed in this section do not limit the present invention or what may be covered in one or more method claims. An exemplary method of some embodiments of the present invention may include the steps of: providing an inlet feed water source including at least one contaminant at a first concentration; passing the inlet feed water through a preheater capable of raising the temperature of the inlet feed water above that required for effective degassing; stripping the inlet feed water having substantially all of the organic matter, volatiles, and gases by flowing the inlet feed water relative to a reverse gas flow in a degasser; maintaining the water in the evaporation chamber for an average residence time between less than one minute and 90 minutes, or longer under conditions allowing steam formation; discharging the steam from the evaporation chamber into a demister; separating the clean steam from the waste mist droplets containing contaminants in the demister such that the yield of the clean steam is at least about 2 times the waste yield from the demister; condensing the clean steam to produce purified water having at least one contaminant at a second concentration; and recovering the heat from the condensation chamber and transferring it to the evaporation chamber or the preheater such that the recovered heat is at least 20% to 95% or more of the condensation heat. Contaminants In some embodiments, the feed water contains at least one contaminant selected from the group consisting of: microorganisms, radionuclides, salts, and organic matter; and wherein the second concentration is not greater than the concentration shown in Table 4, and wherein the first concentration is at least about 10 times the second concentration. Table 4 - Exemplary Contaminants for System Verification 1 MCLG = Maximum Concentration Level Guidance 2 MFL = Million Fibers per Liter 3 pCi / l = picocuries per liter 4 Substantially no detectable biological contaminants In another aspect, the first concentration is at least about 25 times the second concentration. In another aspect, the second concentration is less than the amount permitted by the EPA or other industrial specifications for the industry in which the operating system is used. In another aspect, the gas is selected from the group consisting of: vapor, air, methane, CO2, argon, helium, flue gas, natural gas, flue gas, and flare gas, and mixtures thereof. Self-cleaning In some embodiments, the processing steps are automatically repeated for at least about one day without the need for cleaning or maintenance. In another aspect, the processing steps are automatically repeated for at least one week without the need for cleaning or maintenance. In another aspect, the processing steps are automatically repeated for at least one month without the need for cleaning or maintenance. In another aspect, the processing steps are automatically repeated for at least three months without the need for cleaning or maintenance. In another aspect, the processing steps are automatically repeated for at least about one year without the need for cleaning or maintenance. In another aspect, the system can be cleaned in one stage at a time or in multiple stages at a time in such a way that the entire water treatment system does not necessarily have to be stopped for maintenance. Configuration of the chamber In some embodiments, the evaporation chamber, the condensation chamber, and the preheater in a stacked configuration are enclosed in a metal housing, where a perforated plate separates the evaporation chamber and the condensation chamber. In another aspect, the perforated plate allows the heat pipe, the degasser, the demister, the concentrate overflow pipe, and the waste stream pipe to pass through. In another aspect, the stacked evaporation chamber, condensation chamber, and preheater are composed of individual stages, each stage consisting of: an evaporation chamber, a perforated plate with a heat pipe, and a condensation chamber; or an evaporation chamber, a perforated plate with a heat pipe, and an energy input container; or a condensation chamber, a perforated plate with a heat pipe, and a preheater. In another aspect, the configuration is vertical, horizontal, or at an angle between vertical and horizontal. Materials of the structure In some embodiments, the materials of the structures of the evaporation chamber, the preheater, and the heat pipe are made of a non-corrosive titanium alloy. In another aspect, the non-corrosive titanium alloy is Ti-CP1 alloy. In another aspect, the evaporation chamber, the preheater, and the heat pipe are made of one or more of the following: common steel, stainless steel alloy, nickel alloy, copper alloy, titanium alloy, or other corrosion-resistant alloys, or other metals or metal alloys coated with a non-corrosive chlorofluorocarbon or other non-corrosive polymer. Operation under vacuum In some embodiments, the system can advantageously operate under non-standard environmental conditions, such as some or all of the stage pressures being under vacuum. At pressures less than atmospheric pressure, the boiling point of water, including physiological saline or seawater, is less than 100°C. This low temperature has two basic effects. First, scale formation is greatly reduced at low temperatures. Second, the heat of vaporization / condensation of the solution is greater, meaning that more energy can be transferred from the condensation chamber to the boiler for the same amount of steam. In such embodiments, the preheating temperature can also be significantly affected.If the evaporation chamber temperature is relatively low and the condensation chamber temperature is relatively low, preheating to the desired temperature can be achieved by having a relatively short residence time of water in the preheater, such as by configuring the preheater to be of a smaller volume with the same flow rate, or a higher flow rate with the same volume. In other cases, little or no preheating is required because the stage temperature is relatively low. Combinations with Other Devices In some embodiments, the systems for purifying water, examples of which are disclosed herein, can be combined with other systems and devices to provide other beneficial features. For example, the system can be used in combination with a solar alignment system and device. For example, the system can be used in combination with any one of the devices or methods disclosed in: U.S. Provisional Patent Application No. 60 / 676,870, filed May 2, 2005, entitled SOLAR ALIGNMENT DEVICE; U.S. Provisional Patent Application No. 60 / 697,104, filed Jul. 6, 2005, entitled VISUAL WATER FLOW INDICATOR; U.S. Provisional Patent Application No. 60 / 697,106, filed Jul. 6, 2005, entitled APPARATUS FOR RESTORING THE MINERAL CONTENT OF DRINKING WATER; U.S. Provisional Patent Application No. 60 / 697,107, filed Jul. 6, 2005, entitled IMPROVED CYCLONE DEMISTER; PCT Application No. US2004 / 039993, filed Dec. 1, 2004; PCT Application No. US2004 / 039991, filed Dec. 1, 2004; PCT Application No. US06 / 40103, filed Oct. 13, 2006; PCT Application No. US06 / 40553, filed Oct. 16, 2006; PCT Application No. US2007 / 005270, filed Mar. 2, 2007; PCT Application No. US2008 / 003744, filed Mar. 21, 2008; U.S. Provisional Patent Application No. 60 / 526,580, filed Dec. 2, 2003; and U.S. Provisional Patent Application No. 62 / 456,064, filed Feb. 7, 2017; each of the foregoing applications is incorporated herein by reference in its entirety. Those skilled in the art will understand that these methods and devices are adapted and can be adapted to achieve the purpose, and obtain the results and advantages mentioned, as well as various other advantages and benefits. The methods, procedures, and devices described herein currently represent some embodiments, and are illustrative, and are not intended to limit the scope of the invention. Those skilled in the art will envision variations and other uses that are within the spirit of the invention and are defined by the scope of the invention.External Configuration: Systems with Vacuum In some embodiments, it may be necessary to operate the system at a temperature in one or more of the evaporation chambers such that scale does not form in the chambers due to the evaporation of the feed water in the chambers. The temperature at which scale formation is prevented is typically lower than the standard water boiling point, i.e., 212°F (100°C). One way to achieve a low temperature but still boiling in the evaporation chamber is to create a vacuum in the chamber. By selecting an appropriate vacuum level, the boiling temperature in the chamber can be controlled to remain below the temperature at which scale formation occurs. For such systems, the top brine / concentrate temperature at all stages under vacuum will be <212°F, or less than the temperature at which scale formation occurs for the specific feed water being processed. Another benefit of using a vacuum is that it allows for more stages in the system at the same top brine / concentrate temperature. Vacuum generation can be implemented using a vacuum pump, a vacuum ejector, or a condenser chamber, or a combination of these components. Figure 26 shows an embodiment of a system operating under vacuum. In this embodiment, the evaporation chamber at the top of the stack... generates steam at 20°C, which is fed into the steam ejector 415. In the ejector, the steam from the evaporation chamber is mixed with motive steam at a higher temperature and pressure 420, thereby generating steam at a temperature and pressure high enough to be fed into the energy input vessel 40. This "recompressed" steam 425 is combined with steam from another source 150 to provide enough energy for the condenser chamber 40 to drive the system. The steam ejector 415 creates a vacuum condition in the evaporation chamber 20°C. Boiling occurs, but at a temperature low enough to avoid scale formation. The low temperature of the top evaporation chamber results in low temperatures in all the evaporation chambers and condenser chambers of the system. The steam ejector system is a thermal vapor compression (TVC) system. Figure 27 shows an embodiment similar to Figure 28, but in which instead of using a TVC, a mechanical vapor compression (MVC) 430 is used to compress the steam for reuse. The MVC also creates a vacuum in the evaporation chamber A vacuum is generated at 20°C, thereby generating a low temperature throughout the system and preventing the formation of scale. In another aspect, the system operates with one or more containers at a pressure below atmospheric pressure and one or more containers at or above atmospheric pressure. In another aspect, the system has a deaerator. In another aspect, the system does not have a deaerator. In another aspect, the system has one or more demisters. In another aspect, the system does not have a demister. In another aspect, a pump moves the feed water or the concentrate or both between the stages. In another aspect, the feed water or the concentrate or both move between the stages by gravity. In another aspect, the feed water or the concentrate or both move between the stages using the pressure difference generated by the temperature difference between the stages. In another aspect, the purified water is delivered one or more times between the condensation chambers. In another aspect, the purified water leaves each condensation chamber individually. In another aspect, in some condensation chambers the purified water is delivered between the condensation chambers and directly leaves other condensation chambers. In another aspect, the feed water is first fed into the evaporation chamber with the lowest temperature. In another aspect, the feed water is first fed into the evaporation chamber with the highest temperature. In another aspect, the feed water is fed individually into one or all of the evaporation chambers. In another aspect, the system includes means for steam recompression or steam reheating or both. In another aspect, the steam recompression system is mechanical vapor compression (MVC) or thermal vapor compression (TVC). In another aspect, the steam for recompression or reheating comes from the evaporation chamber with the lowest temperature. In another aspect, the steam for recompression or reheating comes from one or more of the evaporation chambers with intermediate temperatures. In another aspect, the steam for recompression or reheating is delivered to the condensation chamber with the highest temperature. In another aspect, the steam for recompression or reheating is delivered to one or more intermediate condensation chambers. In another aspect, the system includes one or more steam recompressors or reheaters between the evaporation chamber and the condensation chamber. In another aspect, the system has one condensation chamber for generating purified water. In another aspect, the system has multiple condensation chambers for generating purified water. In another aspect, the condensate from the energy input container is recycled to the steam generator. In another aspect, the condensate from the energy input container is combined with the purified water from one or more of the other stages. In another aspect, the stages are stacked vertically. In another aspect, the stages are arranged in parallel. In another aspect, some stages are stacked vertically and some are arranged in parallel. In another aspect, one or more of the stages are horizontally oriented. In another aspect, one or more of the stages are oriented at an angle to the horizontal. In another aspect, one or more of the containers are in the shape of a cylinder, or a sphere, or a cube or a cuboid or a conical solid or a pyramid. In another aspect, the feed water is preheated using purified water or concentrate or both. In another aspect, the system has a pretreatment system. In another aspect, the system does not have a pretreatment system. In another aspect, the system has a post-treatment system.In another aspect, the system does not have a post-treatment system. In another aspect, purified water or concentrate is flash-vaporized and the vapor is delivered to a degasser. In another aspect, the system includes a condenser for air-cooling, water-cooling, or cooling with other chemicals of purified water or concentrate or both. In another aspect, one or more of the condensation chambers are below their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers are above their corresponding evaporation chambers. In another aspect, some of the condensation chambers are below their corresponding evaporation chambers and some are above their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers include one or more steam injectors. In another aspect, none of the condensation chambers include one or more steam injectors. In another aspect, one or more of the steam injectors rotate. In another aspect, the evaporation chambers operate under pool boiling. In another aspect, feed water or concentrate is sprayed onto the heat pipes in one or more of the evaporation chambers. In another aspect, the steam is a source of energy for the energy input vessel. In another aspect, the energy input vessel includes an electric heater, a fuel burner, or a heat pipe that transfers heat from: electricity, solar energy, chemical reactions, nuclear reactions, geothermal sources, molten salts, waste heat from industrial and other processes, flue gas, solid waste energy, heated heat transfer fluids, microwaves, or the combustion of oil, hydrocarbons, biofuels, alcohols, or natural gas, and wherein the energy input vessel is adjacent to or near the evaporation chamber and the two are thermally connected by a heat pipe. In another aspect, combinations of the above energy sources can be used together. In another aspect, the system includes only one stage. In another aspect, the system includes a heat exchanger that captures energy in an intermediate fluid or a fluid leaving the system or both. In another aspect, a portion of the final concentrate leaving the system is recycled back into the system with the feed water to further increase its concentration. In another aspect, some or all of the concentrate leaving the evaporation chamber is recycled back into the evaporation chamber to help reduce scale formation. In another aspect, one or more heat pipes are installed perpendicular to the porous plate. In another aspect, one or more heat pipes are installed at a non-ninety-degree angle to the porous plate. In another aspect, the heat pipes diverge. In another aspect, the heat pipes are all installed at the same height. In another aspect, the heat pipes are installed at different heights. In another aspect, the heat pipes have different lengths. In another aspect, the heat pipes are all of the same length. In another aspect, the system includes annular heat pipes of different lengths. In another aspect, some or all of the system is constructed of titanium or a titanium alloy such as Ti-CP1 or Ti-CP2. In another aspect, some or all of the system is constructed of stainless steel alloys, nickel alloys, copper alloys, or other corrosion-resistant alloys. In another aspect, some or all of the system is constructed of conventional carbon steel or other metal alloys coated with a specific chlorofluorocarbon polymer (e.g., Teflon®) or various polymeric materials resistant to boiling temperatures and physiological saline or chemical environments.In another aspect, some or all of the system is constructed of a metal, ceramic, or cermet composite coating deposited on the walls of the container to prevent corrosion of the container. In another aspect, the hot plate forms some or all of the walls of the system. Systems with vapor recompression In certain embodiments of the present invention, the vapor is obtained from one stage and its pressure is increased such that it can be reinjected back into the previous stage and used again to drive the system. Alternatively, some of the vapor from the system can be "reheated" to increase its temperature and pressure and then reinjected back into the previous stage and used again. Such vapor "recompression" or "reheating" is performed because recompressing or reheating the vapor requires less energy to reach a certain temperature and pressure than generating fresh vapor from liquid water. Energy still needs to be added to the vapor to reach the desired temperature and pressure, but the vaporization energy does not necessarily have to be added at the top. FIG. 26 shows such a system using thermal vapor compression. FIG. 27 shows such a system using mechanical vapor compression. These can be operated by a compression system that generates a vacuum as previously described, or by some or all of the evaporation and condensation chambers of a system operating above atmospheric pressure. In another aspect, the system operates at some or all container pressures at or above atmospheric pressure. In another aspect, the system operates at some or all container pressures under vacuum (less than atmospheric pressure) conditions. In another aspect, the system operates with one or more containers below atmospheric pressure and one or more containers at or above atmospheric pressure. In another aspect, the system has a degasser. In another aspect, the system does not have a degasser. In another aspect, the system has one or more demisters. In another aspect, the system does not have a demister. In another aspect, a pump moves the feed water or concentrate or both between stages. In another aspect, the feed water or concentrate or both move between stages by gravity. In another aspect, the feed water or concentrate or both move between stages using the pressure difference generated by the temperature difference between stages. In another aspect, the purified water is delivered one or more times between the condensation chambers. In another aspect, the purified water leaves each condensation chamber individually. In another aspect, in some condensation chambers the purified water is delivered between the condensation chambers and directly leaves other condensation chambers. In another aspect, the feed water is first fed into the evaporation chamber with the lowest temperature. In another aspect, the feed water is first fed into the evaporation chamber with the highest temperature. In another aspect, the feed water is fed individually into one or all of the evaporation chambers. In another aspect, the vapor recompression system is mechanical vapor compression (MVC) or thermal vapor compression (TVC). In another aspect, the vapor used for recompression / reheating comes from the evaporation chamber with the lowest temperature. In another aspect, the vapor used for recompression / reheating comes from one or more of the evaporation chambers with intermediate temperatures. In another aspect, the recompressed or reheated vapor is delivered to the condensation chamber with the highest temperature. In another aspect, the recompressed or reheated vapor is delivered to one or more intermediate condensation chambers.In another aspect, the system includes one or more steam recompressors or reheaters between the evaporation chamber and the condensation chamber. In another aspect, the system has a condensation chamber that produces purified water. In another aspect, the system has multiple condensation chambers that produce purified water. In another aspect, condensate from the energy input vessel is recycled to the steam generator. In another aspect, condensate from the energy input vessel is combined with purified water from one or more of the other stages. In another aspect, the stages are stacked vertically. In another aspect, the stages are arranged in parallel. In another aspect, some stages are stacked vertically and some are arranged in parallel. In another aspect, one or more of the stages are horizontally oriented. In another aspect, one or more of the stages are oriented at an angle to the horizontal. In another aspect, one or more of the vessels are in the shape of a cylinder, or a sphere, or a cube or a cuboid or a conical solid or a pyramid. In another aspect, purified water or concentrate or both are used to preheat the feed water. In another aspect, the system does not have a pretreatment system. In another aspect, the system has a pretreatment system. In another aspect, the system has a post-treatment system. In another aspect, the system does not have a post-treatment system. In another aspect, purified water or concentrate is flashed and the steam is delivered to a deaerator. In another aspect, the system includes a condenser for air cooling, water cooling or cooling with other chemicals for purified water or concentrate or both. In another aspect, one or more of the condensation chambers are below their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers are above their corresponding evaporation chambers. In another aspect, some condensation chambers are below their corresponding evaporation chambers and some are above their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers include one or more steam ejectors. In another aspect, none of the condensation chambers include one or more steam ejectors. In another aspect, one or more of the steam ejectors rotate. In another aspect, the evaporation chamber operates under pool boiling. In another aspect, the feed water or concentrate is sprayed onto the heat pipes in one or more of the evaporation chambers. In another aspect, the steam is the source of energy for the energy input vessel. In another aspect, the energy input vessel includes an electric heater, a fuel burner or a heat pipe that transfers heat from: electricity, steam, solar energy, chemical reactions, nuclear reactions, geothermal sources, molten salts, waste heat from industrial and other processes, flue gas, solid waste energy, heated heat transfer fluids, microwaves or the combustion of oil, hydrocarbons, biofuels, alcohols or natural gas, and wherein the energy input vessel is adjacent to or near the evaporation chamber and the two are thermally connected by a heat pipe. In another aspect, a combination of the above energy sources can be used together. In another aspect, the system includes only one stage. In another aspect, the system includes a heat exchanger that captures energy in the intermediate fluid or the fluid leaving the system or both. In another aspect, a portion of the final concentrate leaving the system is recycled back into the system with the feed water to further increase its concentration.In another aspect, some or all of the concentrate leaving the evaporation chamber is recycled back into the evaporation chamber to help reduce scale formation. In another aspect, one or more heat pipes are installed perpendicular to the porous plate. In another aspect, one or more heat pipes are installed at an angle other than ninety degrees to the porous plate. In another aspect, the heat pipes diverge. In another aspect, the heat pipes are all installed at the same height. In another aspect, the heat pipes are installed at different heights. In another aspect, the heat pipes have different lengths. In another aspect, the heat pipes are all of the same length. In another aspect, the system includes annular heat pipes of different lengths. In another aspect, some or all of the system is constructed of titanium or a titanium alloy such as Ti-CP1 or Ti-CP2. In another aspect, some of all of the system is constructed of a stainless steel alloy, a nickel alloy, a copper alloy, or other corrosion-resistant alloy. In another aspect, some or all of the system is constructed of conventional carbon steel or other metal alloys coated with a specific chlorofluorocarbon polymer (e.g., Teflon®) or various polymeric materials resistant to boiling temperatures and physiological saline or chemical environments. In another aspect, some or all of the system is constructed of a metal, ceramic, or cermet composite coating deposited on the container wall to prevent container corrosion. In another aspect, the hot plate forms some or all of the walls of the system. Systems with a single water production condensation chamber One embodiment of the system includes a single purified water production condensation chamber. In this configuration, the capital cost of the system can be minimized. The top brine / concentrate / solution temperature is also minimized. Figure 28 shows the use of a steam generator. 140 via the energy input vessel 40 to drive one such embodiment of the system. Feed the feed water 45 into the preheater 10. Then feed the preheated feed water 80 into the evaporation chamber 20. The condensation chamber 35 produces purified water. Condensate from the energy input vessel 40 435 is fed back to the steam generator In 140, water and energy are saved. In this embodiment, heat pipes or other phase change heat transfer devices are used in all stages and the energy input container. A single-stage feed water concentrator can also be designed. In such a system, the feed water will be directly delivered to the evaporation chamber of the energy input container. No purified water is produced. However, when the evaporation chamber uses the energy from the energy input container to boil the feed water, a concentrate will be produced. This energy will be transferred to the evaporator using a heat pipe or other phase change heat transfer device. In another aspect, the system operates with some or all of the container pressures at or above atmospheric pressure. In another aspect, the system operates with some or all of the container pressures under vacuum (less than atmospheric pressure) conditions. In another aspect, the system operates with one or more containers below atmospheric pressure and one or more containers at or above atmospheric pressure. In another aspect, the system has a deaerator. In another aspect, the system does not have a deaerator. In another aspect, the system has one or more demisters. In another aspect, the system does not have a demister. In another aspect, a pump moves the feed water or the concentrate or both. In another aspect, the feed water or the concentrate or both move by gravity. In another aspect, the feed water or the concentrate or both move using the pressure difference generated by the temperature difference between the stage and the ambient atmosphere. In another aspect, the system includes means for steam recompression or steam reheating or both. In another aspect, the steam recompression system is mechanical vapor compression (MVC) or thermal vapor compression (TVC). In another aspect, the condensate from the energy input container is recovered to the steam generator. In another aspect, the condensate from the energy input container is combined with the purified water from the condensate chamber of the produced water. In another aspect, the stages are stacked vertically. In another aspect, the stages are arranged in parallel. In another aspect, one or more of the stages are horizontally oriented. In another aspect, one or more of the stages are oriented at an angle to the horizontal. In another aspect, one or more of the containers are in the shape of a cylinder, or a sphere, or a cube or a cuboid or a conical solid or a pyramid. In another aspect, the feed water is preheated using purified water or the concentrate or both. In another aspect, the system does not have a pretreatment system. In another aspect, the system has a pretreatment system. In another aspect, the system has a post-treatment system. In another aspect, the system does not have a post-treatment system. In another aspect, the purified water or the concentrate is flashed and the steam is delivered to the deaerator. In another aspect, the system includes a condenser for air cooling, water cooling or other chemical cooling of the purified water or the concentrate or both. In another aspect, the condenser is below the corresponding evaporation chamber. In another aspect, the condenser is above the corresponding evaporation chamber. In another aspect, some of the condensate chambers are below their corresponding evaporation chambers and some of the condensate chambers are above their corresponding evaporation chambers. In another aspect, the condenser includes one or more steam ejectors. In another aspect, the condenser does not include one or more steam ejectors.In another aspect, one or more steam injectors rotate. In another aspect, the evaporation chamber operates under pool boiling. In another aspect, feed water or concentrate is sprayed onto the heat pipes in the evaporation chamber. In another aspect, the steam is a source of energy for the energy input vessel. In another aspect, the energy input vessel includes an electric heater, a fuel burner, or a heat pipe that transfers heat from: electricity, steam, solar energy, chemical reactions, nuclear reactions, geothermal sources, molten salts, waste heat from industrial and other processes, flue gas, solid waste energy, heated heat transfer fluids, microwaves, or the combustion of oil, hydrocarbons, biofuels, alcohols, or natural gas, and wherein the energy input vessel is adjacent to or near the evaporation chamber and the two are thermally connected by a heat pipe. In another aspect, combinations of the above energy sources can be used together. In another aspect, the system includes only one stage. In another aspect, the system includes a heat exchanger that captures energy in an intermediate fluid or a fluid leaving the system or both. In another aspect, a portion of the final concentrate leaving the system is recycled back into the system with the feed water to further increase its concentration. In another aspect, some or all of the concentrate leaving the evaporation chamber is recycled back into the evaporation chamber to help reduce scale formation. In another aspect, one or more heat pipes are installed perpendicular to the porous plate. In another aspect, one or more heat pipes are installed at a non-ninety-degree angle to the porous plate. In another aspect, the heat pipes diverge. In another aspect, the heat pipes are all installed at the same height. In another aspect, the heat pipes are installed at different heights. In another aspect, the heat pipes have different lengths. In another aspect, the heat pipes are all of the same length. In another aspect, the system includes annular heat pipes of different lengths. In another aspect, some or all of the system is constructed of titanium or titanium alloys such as Ti-CP1 or Ti-CP2. In another aspect, some of all of the system is constructed of stainless steel alloys, nickel alloys, copper alloys, or other corrosion-resistant alloys. In another aspect, some or all of the system is constructed of conventional carbon steel or other metal alloys coated with specific chlorofluorocarbon polymers (such as Teflon®) or various polymeric materials resistant to boiling temperatures and physiological saline or chemical environments. In another aspect, some or all of the system is constructed of metal, ceramic, or cermet composite coatings deposited on the container walls to prevent container corrosion. In another aspect, the hot plate forms some or all of the walls of the system. Heat pipes in a vapor compression evaporator One embodiment of the system includes a variation of a vapor compression evaporator where heat transfer is achieved using heat pipes instead of standard falling or rising film and tubes. This system has a single stage of vapor recompression and typically includes concentrate recycling. Figure 29 shows such a system. Feed water 45 is fed into the evaporation chamber 20, where steam is generated. After passing through the demister, the clean steam 50 is delivered to the mechanical vapor compressor in 430, where its temperature and pressure increase. This recompressed steam combines with the steam from the steam generator 140 or the steam from another steam source 150. The purified water condenses in the condenser 35 and leaves the system. The concentrate 55 leaves the evaporation chamber. Some of the concentrate can be recycled and added to the feed water to enable the system to produce a more concentrated final concentrate 55 It is possible. In another aspect, the system operates with the container pressure at or above atmospheric pressure. In another aspect, the system operates with the container pressure under vacuum (less than atmospheric pressure) conditions. In another aspect, the system operates with one or more containers below atmospheric pressure and one or more containers at or above atmospheric pressure. In another aspect, the system has a degasser. In another aspect, the system does not have a degasser. In another aspect, the system has one or more demisters. In another aspect, the system does not have a demister. In another aspect, a pump moves the feed water or the concentrate or both. In another aspect, the feed water or the concentrate or both move by gravity. In another aspect, the feed water or the concentrate or both move using the pressure difference generated by the temperature difference between the containers. In another aspect, the system includes means for steam recompression or steam reheating or both. In another aspect, the steam recompression system is mechanical vapor compression (MVC) or thermal vapor compression (TVC). In another aspect, the condensate from the energy input container is recycled to the steam generator. In another aspect, the system is horizontally oriented. In another aspect, the system is oriented at an angle to the horizontal. In another aspect, one or more of the containers are in the shape of a cylinder, or a sphere, or a cube or a cuboid or a conical solid or a pyramid. In another aspect, purified water or concentrate or both are used to preheat the feed water. In another aspect, the system does not have a pretreatment system. In another aspect, the system has a pretreatment system. In another aspect, the system has a post-treatment system. In another aspect, the system does not have a post-treatment system. In another aspect, the purified water or concentrate is flashed and the steam is delivered to the degasser. In another aspect, the system includes a condenser for air cooling, water cooling or cooling with other chemicals for the purified water or concentrate or both. In another aspect, the condenser is below its corresponding evaporation chamber. In another aspect, the condenser is above its corresponding evaporation chamber. In another aspect, the condenser includes one or more steam ejectors. In another aspect, the condenser does not include one or more steam ejectors. In another aspect, one or more of the steam ejectors rotate. In another aspect, the evaporation chamber operates under pool boiling. In another aspect, the feed water or concentrate is sprayed onto the heat pipes in the evaporation chamber. In another aspect, the steam is the source of energy for the energy input container. In another aspect, the energy input container includes an electric heater, a fuel burner or a heat pipe that transfers heat from: electricity, steam, solar energy, chemical reactions, nuclear reactions, geothermal sources, molten salts, waste heat from industrial and other processes, flue gas, solid waste energy, heated heat transfer fluid, microwaves or the combustion of oil, hydrocarbons, biofuels, alcohols or natural gas, and wherein the energy input container is adjacent to or near the evaporation chamber and the two are thermally connected by a heat pipe. In another aspect, a combination of the above energy sources can be used together. In another aspect, the system includes only one stage.In another aspect, the system includes a heat exchanger that captures energy in the intermediate fluid or the fluid leaving the system or both. In another aspect, a portion of the final concentrate leaving the system is recycled back to the system with the feed water to further increase its concentration. In another aspect, one or more heat pipes are installed perpendicular to the porous plate. In another aspect, one or more heat pipes are installed at an angle other than ninety degrees to the porous plate. In another aspect, the heat pipes are splayed. In another aspect, the heat pipes are all installed at the same height. In another aspect, the heat pipes are installed at different heights. In another aspect, the heat pipes have different lengths. In another aspect, the heat pipes are all of the same length. In another aspect, the system includes annular heat pipes of different lengths. In another aspect, some or all of the system is constructed of titanium or a titanium alloy such as Ti-CP1 or Ti-CP2. In another aspect, some of all of the system is constructed of a stainless steel alloy, a nickel alloy, a copper alloy, or other corrosion-resistant alloy. In another aspect, some or all of the system is constructed of conventional carbon steel or other metal alloys coated with a specific chlorofluorocarbon polymer (e.g., Teflon®) or various polymeric materials resistant to boiling temperatures and physiological saline or chemical environments. In another aspect, some or all of the system is constructed of a metal, ceramic, or cermet composite coating deposited on the container walls to prevent container corrosion. In another aspect, the hot plate forms some or all of the walls of the system. In another aspect, the feed water can be "seeded" to produce scale on which additional scale formed during the evaporation process adheres. System in horizontal configuration Figure 30 shows a stage configured with heat pipes in a horizontal position. Examples of 25 (or other heat transfer devices), the evaporation chamber, and the condensation chamber. Feed water 45 is introduced into the preheater, sprayed onto the heat pipes and with the preheated feed water 80 and the intermediate concentrate 70 is transferred between the evaporation chambers. Purified water 65 is removed from the condenser of each stage and the final concentrate 55 is removed from the final evaporation chamber. Steam generator 140 with steam 150 supplies energy to the system. The condensate from the energy input vessel returns to the steam generator. In another aspect, the system operates with some or all of the vessel pressures at or above atmospheric pressure. In another aspect, the system operates with some or all of the vessel pressures under vacuum (less than atmospheric pressure) conditions. In another aspect, the system operates with one or more vessels below atmospheric pressure and one or more vessels at or above atmospheric pressure. In another aspect, the system has a deaerator. In another aspect, the system does not have a deaerator. In another aspect, the system has one or more demisters. In another aspect, the system does not have a demister. In another aspect, a pump moves feed water or concentrate or both between stages. In another aspect, the feed water or concentrate or both move between evaporation chambers by gravity. In another aspect, the feed water or concentrate or both move between evaporation chambers using the pressure difference generated by the temperature difference between the evaporation chambers. In another aspect, purified water is delivered one or more times between condensation chambers. In another aspect, purified water leaves each condensation chamber individually. In another aspect, in some condensation chambers, purified water is delivered between condensation chambers and directly leaves other condensation chambers. In another aspect, the feed water is first fed into the evaporation chamber with the lowest temperature. In another aspect, the feed water is first fed into the evaporation chamber with the highest temperature. In another aspect, the feed water is fed individually into one or all of the evaporation chambers. In another aspect, the system includes means for steam recompression or steam reheating or both. In another aspect, the steam recompression system is mechanical vapor compression (MVC) or thermal vapor compression (TVC). In another aspect, the steam for recompression or reheating or both comes from the evaporation chamber with the lowest temperature. In another aspect, the steam for recompression or reheating or both comes from one or more of the intermediate temperature evaporation chambers. In another aspect, the steam for recompression or reheating is delivered to the condensation chamber with the highest temperature. In another aspect, the steam for recompression or reheating is delivered to one or more intermediate condensation chambers. In another aspect, the system includes one or more steam recompressors or reheaters between the evaporation chamber and the condensation chamber. In another aspect, the system has one condensation chamber for producing purified water. In another aspect, the system has multiple condensation chambers for producing purified water. In another aspect, the condensate from the energy input vessel is recycled to the steam generator. In another aspect, the condensate from the energy input vessel is combined with purified water from one or more of the other stages. In another aspect, the stages are stacked vertically. In another aspect, the stages are arranged in parallel. In another aspect, some stages are stacked vertically and some are arranged in parallel. In another aspect, one or more of the stages are oriented at an angle to the horizontal. In another aspect, one or more of the vessels are in the shape of a cylinder, or a sphere, or a cube or a cuboid or a conical solid or a pyramid. In another aspect, purified water or concentrate or both are used to preheat the feed water.In another aspect, the system does not have a pre-treatment system. In another aspect, the system has a pre-treatment system. In another aspect, the system has a post-treatment system. In another aspect, the system does not have a post-treatment system. In another aspect, purified water or concentrate is flashed and the steam is delivered to a degasser. In another aspect, the system includes a condenser for air-cooling, water-cooling, or cooling with other chemicals of purified water or concentrate or both. In another aspect, one or more of the condensation chambers are below their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers are above their corresponding evaporation chambers. In another aspect, some of the condensation chambers are below their corresponding evaporation chambers and some of the condensation chambers are above their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers include one or more steam injectors. In another aspect, none of the condensation chambers include one or more steam injectors. In another aspect, one or more of the steam injectors rotate. In another aspect, the evaporation chambers operate under pool boiling. In another aspect, feed water or concentrate is sprayed onto the heat pipes in one or more of the evaporation chambers. In another aspect, the steam is the source of the energy of the energy input vessel. In another aspect, the energy input vessel includes an electric heater, a fuel burner, or a heat pipe that transfers heat from: electricity, steam, solar energy, chemical reactions, nuclear reactions, geothermal sources, molten salts, waste heat from industrial and other processes, flue gas, solid waste energy, heated heat transfer fluids, microwaves, or the combustion of oil, hydrocarbons, biofuels, alcohols, or natural gas, and wherein the energy input vessel is adjacent to or near the evaporation chamber and the two are thermally connected by a heat pipe. In another aspect, combinations of the above energy sources can be used together. In another aspect, the system includes only one stage. In another aspect, the system includes a heat exchanger that captures energy in the intermediate fluid or the fluid leaving the system or both. In another aspect, a portion of the final concentrate leaving the system is recycled back to the system with the feed water to further increase its concentration. In another aspect, some or all of the concentrate leaving the evaporation chamber is recycled back to the evaporation chamber to help reduce scale formation. In another aspect, one or more heat pipes are installed perpendicular to the porous plate. In another aspect, one or more heat pipes are installed at an angle other than ninety degrees to the porous plate. In another aspect, the heat pipes flare. In another aspect, the heat pipes are all installed at the same distance from the porous plate at the ends of the heat pipes. In another aspect, the heat pipes are installed at different distances from the porous plate at the ends of the heat pipes. In another aspect, the heat pipes have different lengths. In another aspect, the heat pipes are all of the same length. In another aspect, the system includes annular heat pipes of different lengths. In another aspect, some or all of the system is constructed of titanium or titanium alloys such as Ti-CP1 or Ti-CP2. In another aspect, some of all of the system is constructed of stainless steel alloys, nickel alloys, copper alloys, or other corrosion-resistant alloys.In another aspect, some or all of the system is constructed of conventional carbon steel or other metal alloys coated with a specific chlorofluorocarbon polymer (such as Teflon®) or various polymeric materials resistant to boiling temperatures and physiological saline or chemical environments. In another aspect, some or all of the system is constructed of a metal, ceramic, or cermet composite coating deposited on the walls of the container to prevent corrosion of the container. In another aspect, the hot plate forms some or all of the walls of the system. Internal Configuration Systems with Water Spray / Film Boiling The feed water or intermediate concentrate can be sprayed onto heat pipes, thermosyphons, annular heat pipes, etc., rather than leaving those elements sitting in a pool of feed water or intermediate concentrate. In these embodiments, the spray of the feed water or intermediate concentrate is directed onto the heat pipes in the evaporation chamber to create film boiling or evaporation conditions. Figure 31(a) shows the evaporation chamber 345 via a nebulizer with the intermediate concentrate 20 in the evaporation chamber 70 sprayed onto the heat pipe 25 in the embodiment shown. Figure 31(b) shows the use of a "spray head" type spreader 345 to spray the feed water or intermediate concentrate Example on a 25 - array. Figure 31(c) shows a similar configuration with a horizontally - arranged evaporation chamber and condenser. In another aspect, the system operates with some or all of the container pressures at or above atmospheric pressure. In another aspect, the system operates with some or all of the container pressures under vacuum (less than atmospheric pressure) conditions. In another aspect, the system operates with one or more containers at a pressure lower than atmospheric pressure and one or more containers at or above atmospheric pressure. In another aspect, the system has a deaerator. In another aspect, the system does not have a deaerator. In another aspect, the system has one or more demisters. In another aspect, the system does not have a demister. In another aspect, a pump moves the feed water or the concentrate or both between the stages. In another aspect, the feed water or the concentrate or both move between the stages by gravity. In another aspect, the feed water or the concentrate or both move between the stages using the pressure difference generated by the temperature difference between the stages. In another aspect, the purified water is delivered one or more times between the condensation chambers. In another aspect, the purified water leaves each condensation chamber individually. In another aspect, in some condensation chambers the purified water is delivered between the condensation chambers and directly leaves other condensation chambers. In another aspect, the feed water is first fed into the evaporation chamber with the lowest temperature. In another aspect, the feed water is first fed into the evaporation chamber with the highest temperature. In another aspect, the feed water is fed individually into one or all of the evaporation chambers. In another aspect, the system includes means for steam recompression or steam reheating or both. In another aspect, the steam recompression system is mechanical vapor compression (MVC) or thermal vapor compression (TVC). In another aspect, the steam for recompression or reheating or both comes from the evaporation chamber with the lowest temperature. In another aspect, the steam for recompression or reheating or both comes from one or more of the evaporation chambers with intermediate temperatures. In another aspect, the steam for recompression or reheating is delivered to the condensation chamber with the highest temperature. In another aspect, the steam for recompression or reheating is delivered to one or more intermediate condensation chambers. In another aspect, the system includes one or more steam recompressors or reheaters between the evaporation chamber and the condensation chamber. In another aspect, the system has one condensation chamber for producing purified water. In another aspect, the system has multiple condensation chambers for producing purified water. In another aspect, the condensate from the energy - input container is recycled to the steam generator. In another aspect, the condensate from the energy - input container is combined with the purified water from one or more of the condensation chambers. In another aspect, the stages are stacked vertically. In another aspect, the stages are arranged in parallel. In another aspect, some stages are stacked vertically and some are arranged in parallel. In another aspect, one or more of the stages are horizontally oriented. In another aspect, one or more of the stages are oriented at an angle to the horizontal. In another aspect, one or more of the containers are in the shape of a cylinder, or a sphere, or a cube, or a cuboid, or a conical solid, or a pyramid.In another aspect, purified water or concentrate or both are used to preheat the feed water. In another aspect, the system does not have a pretreatment system. In another aspect, the system has a pretreatment system. In another aspect, the system has a post-treatment system. In another aspect, the system does not have a post-treatment system. In another aspect, the purified water or concentrate is flashed and the steam is delivered to a deaerator. In another aspect, the system includes a condenser for air-cooling, water-cooling or cooling with other chemicals for purified water or concentrate or both. In another aspect, one or more of the condensation chambers are below their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers are above their corresponding evaporation chambers. In another aspect, some of the condensation chambers are below their corresponding evaporation chambers and some are above their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers include one or more steam ejectors. In another aspect, none of the condensation chambers include one or more steam ejectors. In another aspect, one or more steam ejectors rotate. In another aspect, the evaporation chambers operate under pool boiling. In another aspect, the feed water or concentrate is sprayed onto the heat pipes in one or more of the evaporation chambers. In another aspect, the steam is the source of the energy of the energy input vessel. In another aspect, the energy input vessel includes an electric heater, a fuel burner or a heat pipe that transfers heat from: electricity, steam, solar energy, chemical reaction, nuclear reaction, geothermal source, molten salt, waste heat from industrial and other processes, flue gas, solid waste energy, heated heat transfer fluid, microwave or combustion of oil, hydrocarbon, biofuel, alcohol or natural gas, and wherein the energy input vessel is adjacent or close to the evaporation chamber and the two are thermally connected by a heat pipe. In another aspect, combinations of the above energy sources can be used together. In another aspect, the system includes only one stage. In another aspect, the system includes a heat exchanger that captures energy in the intermediate fluid or the fluid leaving the system or both. In another aspect, a portion of the final concentrate leaving the system is circulated back into the system with the feed water to further increase its concentration. In another aspect, some or all of the concentrate leaving the evaporation chamber is circulated back into the evaporation chamber to help reduce scale formation. In another aspect, one or more heat pipes are installed perpendicular to the porous plate. In another aspect, one or more heat pipes are installed at an angle other than ninety degrees to the porous plate. In another aspect, the heat pipes diverge. In another aspect, the heat pipes are all installed at the same height. In another aspect, the heat pipes are installed at different heights. In another aspect, the heat pipes have different lengths. In another aspect, the heat pipes are all of the same length. In another aspect, the system includes annular heat pipes of different lengths. In another aspect, some or all of the system is constructed of titanium or a titanium alloy such as Ti-CP1 or Ti-CP2. In another aspect, some of all of the system is constructed of a stainless steel alloy, a nickel alloy, a copper alloy or other corrosion-resistant alloy.In another aspect, some or all of the system is constructed of conventional carbon steel or other metal alloys coated with a specific chlorofluorocarbon polymer (such as Teflon®) or various polymeric materials resistant to boiling temperatures and physiological saline or chemical environments. In another aspect, some or all of the system is constructed of a metal, ceramic, or cermet composite coating deposited on the walls of the container to prevent corrosion of the container. In another aspect, the hot plate forms some or all of the walls of the system. Systems with annular heat pipes Figure 32(a) shows a configuration of an annular heat pipe. One embodiment of the present invention at 640, one per stage, in the stage condensation chamber 35 and the stage evaporation chamber 20. Figure 32(b) shows a second embodiment of the present invention, where the annular heat pipe not only extends from the condensation chamber 35 to its corresponding evaporation chamber 20, but also from the condensation chamber 35 to the previous evaporation chamber One of the 20 operates to produce water more similarly at all stages. Note: These embodiments are illustrative and not intended to limit the spirit of the invention. In another aspect, the system operates with some or all of the container pressures at or above atmospheric pressure. In another aspect, the system operates with some or all of the container pressures under vacuum (less than atmospheric pressure) conditions. In another aspect, the system operates with one or more containers below atmospheric pressure and one or more containers at or above atmospheric pressure. In another aspect, the system has a degasser. In another aspect, the system does not have a degasser. In another aspect, the system has one or more demisters. In another aspect, the system does not have a demister. In another aspect, a pump moves the feed water or the concentrate or both between the stages. In another aspect, the feed water or the concentrate or both move between the stages by gravity. In another aspect, the feed water or the concentrate or both move between the evaporation chambers using the pressure difference generated by the temperature difference between the evaporation chambers. In another aspect, the purified water is delivered one or more times between the condensation chambers. In another aspect, the purified water leaves each condensation chamber individually. In another aspect, in some condensation chambers the purified water is delivered between the condensation chambers and directly leaves the other condensation chambers. In another aspect, the feed water is first fed into the evaporation chamber with the lowest temperature. In another aspect, the feed water is first fed into the evaporation chamber with the highest temperature. In another aspect, the feed water is fed individually into one or all of the evaporation chambers. In another aspect, the system includes means for steam recompression or steam reheating or both. In another aspect, the steam recompression system is mechanical vapor compression (MVC) or thermal vapor compression (TVC). In another aspect, the steam for recompression or reheating or both comes from the evaporation chamber with the lowest temperature. In another aspect, the steam for recompression or reheating or both comes from one or more of the intermediate temperature evaporation chambers. In another aspect, the steam for recompression or reheating is delivered to the condensation chamber with the highest temperature. In another aspect, the steam for recompression or reheating is delivered to one or more intermediate condensation chambers. In another aspect, the system includes one or more steam recompressors or reheaters between the evaporation chamber and the condensation chamber. In another aspect, the system has one condensation chamber for producing purified water. In another aspect, the system has multiple condensation chambers for producing purified water. In another aspect, the condensate from the energy input container is recycled to the steam generator. In another aspect, the condensate from the energy input container is combined with the purified water from one or more of the other stages. In another aspect, the stages are stacked vertically. In another aspect, the stages are arranged in parallel. In another aspect, some stages are stacked vertically and some are arranged in parallel. In another aspect, one or more of the stages are horizontally oriented. In another aspect, one or more of the stages are oriented at an angle to the horizontal.In another aspect, one or more of the containers are in the shape of a cylinder, or a sphere, or a cube or a cuboid or a conical solid or a pyramid. In another aspect, purified water or concentrate or both are used to preheat the feed water. In another aspect, the system does not have a pretreatment system. In another aspect, the system has a pretreatment system. In another aspect, the system has a post-treatment system. In another aspect, the system does not have a post-treatment system. In another aspect, the purified water or concentrate is flashed and the steam is delivered to a deaerator. In another aspect, the system includes a condenser for air cooling, water cooling or cooling with other chemicals for purified water or concentrate or both. In another aspect, one or more of the condensation chambers are below their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers are above their corresponding evaporation chambers. In another aspect, some of the condensation chambers are below their corresponding evaporation chambers and some of the condensation chambers are above their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers include one or more steam injectors. In another aspect, none of the condensation chambers include one or more steam injectors. In another aspect, one or more of the steam injectors rotate. In another aspect, the evaporation chamber operates under pool boiling. In another aspect, the feed water or concentrate is sprayed onto the heat pipes in one or more of the evaporation chambers. In another aspect, the steam is the source of the energy input to the container. In another aspect, the energy input container includes an electric heater, a fuel burner or a heat pipe that transfers heat from: electricity, steam, solar energy, chemical reactions, nuclear reactions, geothermal sources, molten salts, waste heat from industrial and other processes, flue gas, solid waste energy, heated heat transfer fluids, microwaves or the combustion of oil, hydrocarbons, biofuels, alcohols or natural gas, and wherein the energy input container is adjacent to or near the evaporation chamber and the two are thermally connected by a heat pipe. In another aspect, combinations of the above energy sources can be used together. In another aspect, the system includes only one container. In another aspect, the system includes a heat exchanger that captures energy in the intermediate fluid or the fluid leaving the system or both. In another aspect, a portion of the final concentrate leaving the system is recycled back to the system with the feed water to further increase its concentration. In another aspect, some or all of the concentrate leaving the evaporation chamber is recycled back to the evaporation chamber to help reduce scale formation. In another aspect, one or more of the heat pipes are installed perpendicular to the perforated plate. In another aspect, one or more of the heat pipes are installed at an angle other than ninety degrees to the perforated plate. In another aspect, the heat pipes are flared. In another aspect, the system includes annular heat pipes of different lengths. In another aspect, some or all of the system is constructed of titanium or titanium alloys such as Ti-CP1 or Ti-CP2. In another aspect, some of all of the system is constructed of stainless steel alloys, nickel alloys, copper alloys or other corrosion-resistant alloys.In another aspect, some or all of the system is constructed of conventional carbon steel or other metal alloys coated with a specific chlorofluorocarbon polymer (such as Teflon®) or various polymeric materials resistant to boiling temperatures and physiological saline or chemical environments. In another aspect, some or all of the system is constructed of a metal, ceramic, or cermet composite coating deposited on the walls of the container to prevent corrosion of the container. In another aspect, the hot plate forms some or all of the walls of the system. Systems with angled heat pipes In some embodiments, some forms of heat pipes function more effectively when they are at an angle slightly off vertical. FIG. 33(a) shows one such embodiment of the present invention. In this embodiment, the heat pipe... 25 by an angle ϴ 440 tilting the entire stage (evaporation chamber 20 and condenser 35) is arranged at an angle off vertical. In another embodiment, the heat pipes in the stage are installed at an angle off vertical. In another embodiment, FIG. 33(b), in the evaporation chamber 20 or the heat pipes in the preheater are formed in an open configuration. In another aspect, the system operates with some or all of the container pressures at or above atmospheric pressure. In another aspect, the system operates with some or all of the container pressures under vacuum (less than atmospheric pressure) conditions. In another aspect, the system operates with one or more containers at less than atmospheric pressure and one or more containers at or above atmospheric pressure. In another aspect, the system has a degasser. In another aspect, the system does not have a degasser. In another aspect, the system has one or more demisters. In another aspect, the system does not have a demister. In another aspect, a pump moves the feed water or the concentrate or both between the stages. In another aspect, the feed water or the concentrate or both move between the stages by gravity. In another aspect, the feed water or the concentrate or both move between the stages using the pressure difference generated by the temperature difference between the stages. In another aspect, the purified water is delivered between the condensation chambers one or more times. In another aspect, the purified water leaves each condensation chamber individually. In another aspect, in some condensation chambers the purified water is delivered between the condensation chambers and directly leaves the other condensation chambers. In another aspect, the feed water is first fed into the evaporation chamber with the lowest temperature. In another aspect, the feed water is first fed into the evaporation chamber with the highest temperature. In another aspect, the feed water is individually fed into one or all of the stages. In another aspect, the system includes means for steam recompression or steam reheating or both. In another aspect, the steam recompression system is mechanical vapor compression (MVC) or thermal vapor compression (TVC). In another aspect, the steam for recompression or reheating or both comes from the evaporation chamber with the lowest temperature. In another aspect, the steam for recompression or reheating or both comes from one or more of the intermediate temperature stages. In another aspect, the steam for recompression or reheating is delivered to the condensation chamber with the highest temperature. In another aspect, the steam for recompression or reheating is delivered to one or more intermediate condensation chambers. In another aspect, the system includes one or more steam recompressors or reheaters between the evaporation chamber and the condensation chamber. In another aspect, the system has one condensation chamber for producing purified water. In another aspect, the system has multiple condensation chambers for producing purified water. In another aspect, the condensate from the energy input container is recycled to the steam generator. In another aspect, the condensate from the energy input container is combined with the purified water from one or more of the other stages. In another aspect, the stages are stacked vertically. In another aspect, the stages are arranged in parallel. In another aspect, some stages are stacked vertically and some are arranged in parallel. In another aspect, one or more of the stages are horizontally oriented. In another aspect, one or more of the stages are oriented at an angle to the horizontal. In another aspect, one or more of the containers are in the shape of a cylinder, or a sphere, or a cube or a cuboid or a conical solid or a pyramid. In another aspect, the feed water is preheated using purified water or concentrate or both.In another aspect, the system does not have a pre-treatment system. In another aspect, the system has a pre-treatment system. In another aspect, the system has a post-treatment system. In another aspect, the system does not have a post-treatment system. In another aspect, purified water or concentrate is flashed and the steam is delivered to a deaerator. In another aspect, the system includes a condenser for air cooling, water cooling, or cooling with other chemicals for purified water or concentrate or both. In another aspect, one or more of the condensation chambers are below their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers are above their corresponding evaporation chambers. In another aspect, some of the condensation chambers are below their corresponding evaporation chambers and some are above their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers include one or more steam injectors. In another aspect, none of the condensation chambers include one or more steam injectors. In another aspect, one or more steam injectors rotate. In another aspect, the evaporation chambers operate under pool boiling. In another aspect, feed water or concentrate is sprayed onto the heat pipes in one or more evaporation chambers. In another aspect, the steam is a source of the energy of the energy input vessel. In another aspect, the energy input vessel includes an electric heater, a fuel burner, or a heat pipe that transfers heat from: electricity, steam, solar energy, chemical reactions, nuclear reactions, geothermal sources, molten salts, waste heat from industrial and other processes, flue gas, solid waste energy, heated heat transfer fluids, microwaves, or the combustion of oil, hydrocarbons, biofuels, alcohols, or natural gas, and wherein the energy input vessel is adjacent to or near the evaporation chamber and the two are thermally connected by a heat pipe. In another aspect, combinations of the above energy sources can be used together. In another aspect, the system includes only one stage. In another aspect, the system includes a heat exchanger that captures energy in the intermediate fluid or the fluid leaving the system or both. In another aspect, a portion of the final concentrate leaving the system is recycled back into the system with the feed water to further increase its concentration. In another aspect, some or all of the concentrate leaving the evaporation chamber is recycled back into the evaporation chamber to help reduce scale formation. In another aspect, one or more heat pipes are installed perpendicular to the porous plate. In another aspect, one or more heat pipes are installed at an angle other than ninety degrees to the porous plate. In another aspect, the heat pipes diverge. In another aspect, the heat pipes are all installed at the same height. In another aspect, the heat pipes are installed at different heights. In another aspect, the heat pipes have different lengths. In another aspect, the heat pipes are all of the same length. In another aspect, the system includes annular heat pipes of different lengths. In another aspect, some or all of the system is constructed of titanium or a titanium alloy such as Ti-CP1 or Ti-CP2. In another aspect, some of all of the system is constructed of stainless steel alloys, nickel alloys, copper alloys, or other corrosion-resistant alloys.In another aspect, some or all of the system is constructed from conventional carbon steel or other metal alloys coated with a specific chlorofluorocarbon polymer (such as Teflon®) or various polymeric materials resistant to boiling temperatures and physiological saline or chemical environments. In another aspect, some or all of the system is constructed from metal, ceramic, or cermet composite coatings deposited on the walls of the container to prevent corrosion of the container. In another aspect, the hot plate forms some or all of the walls of the system. Systems with heat pipes of different heights In some embodiments of the system, the heat pipes can be configured such that they are at different heights in the evaporation chamber, where the central heat pipe is higher or lower, or in some random configuration, or in an ordered configuration (such as alternating rows). Figure 34(a) shows the heat pipes in the evaporation chamber 20 with the central heat pipe installed higher than the further away heat pipes 25. In this configuration, the steam spray from the steam injector 295 can more easily reach the heat pipes in the outer rows in 35. Figure 34(b) shows a configuration with heat pipes where the central heat pipe is lower than the further away heat pipes 25. In the evaporation chamber When the heat pipes in the center of 35 are relatively low, the bubbles formed in the central part of the chamber can more easily float to the top without drying out the adjacent heat pipes. In another aspect, the system operates at some or all of the container pressures at or above atmospheric pressure. In another aspect, the system operates at some or all of the container pressures under vacuum (less than atmospheric pressure) conditions. In another aspect, the system operates with one or more containers below atmospheric pressure and one or more containers at or above atmospheric pressure. In another aspect, the system has a degasser. In another aspect, the system does not have a degasser. In another aspect, the system has one or more demisters. In another aspect, the system does not have a demister. In another aspect, a pump moves the feed water or the concentrate or both between the stages. In another aspect, the feed water or the concentrate or both move between the stages by gravity. In another aspect, the feed water or the concentrate or both move between the stages using the pressure difference generated by the temperature difference between the stages. In another aspect, the purified water is delivered one or more times between the condensation chambers. In another aspect, the purified water leaves each condensation chamber individually. In another aspect, in some of the condensation chambers, the purified water is delivered between the condensation chambers and directly leaves the other condensation chambers. In another aspect, the feed water is first fed into the evaporation chamber with the lowest temperature. In another aspect, the feed water is first fed into the evaporation chamber with the highest temperature. In another aspect, the feed water is fed individually into one or all of the evaporation chambers. In another aspect, the system includes means for steam recompression or steam reheating or both. In another aspect, the steam recompression system is mechanical vapor compression (MVC) or thermal vapor compression (TVC). In another aspect, the steam for recompression or reheating or both comes from the evaporation chamber with the lowest temperature. In another aspect, the steam for recompression or reheating or both comes from one or more of the evaporation chambers with intermediate temperatures. In another aspect, the steam for recompression or reheating is delivered to the condensation chamber with the highest temperature. In another aspect, the steam for recompression or reheating is delivered to one or more intermediate condensation chambers. In another aspect, the system includes one or more steam recompressors or reheaters between the evaporation chamber and the condensation chamber. In another aspect, the system has one condensation chamber for producing purified water. In another aspect, the system has multiple condensation chambers for producing purified water. In another aspect, the condensate from the energy input container is recycled to the steam generator. In another aspect, the condensate from the energy input container is combined with the purified water from one or more of the other stages. In another aspect, the stages are stacked vertically. In another aspect, the stages are arranged in parallel. In another aspect, some of the stages are stacked vertically and some are arranged in parallel. In another aspect, one or more of the stages are horizontally oriented. In another aspect, one or more of the stages are oriented at an angle to the horizontal. In another aspect, one or more of the containers are in the shape of a cylinder, or a sphere, or a cube or a cuboid or a conical solid or a pyramid.In another aspect, purified water or concentrate or both are used to preheat the feed water. In another aspect, the system does not have a pretreatment system. In another aspect, the system has a pretreatment system. In another aspect, the system has a post-treatment system. In another aspect, the system does not have a post-treatment system. In another aspect, the purified water or concentrate is flashed and the steam is delivered to a deaerator. In another aspect, the system includes a condenser for air cooling, water cooling, or other chemical cooling of purified water or concentrate or both. In another aspect, one or more of the condensation chambers are below their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers are above their corresponding evaporation chambers. In another aspect, some of the condensation chambers are below their corresponding evaporation chambers and some are above their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers include one or more steam injectors. In another aspect, none of the condensation chambers include one or more steam injectors. In another aspect, one or more of the steam injectors rotate. In another aspect, the evaporation chambers operate under pool boiling. In another aspect, the feed water or concentrate is sprayed onto the heat pipes in one or more of the evaporation chambers. In another aspect, the steam is the source of energy for the energy input vessel. In another aspect, the energy input vessel includes an electric heater, a fuel burner, or a heat pipe that transfers heat from: electricity, steam, solar energy, chemical reactions, nuclear reactions, geothermal sources, molten salts, waste heat from industrial and other processes, flue gas, solid waste energy, heated heat transfer fluids, microwaves, or the combustion of oil, hydrocarbons, biofuels, alcohols, or natural gas, and wherein the energy input vessel is adjacent to or near the evaporation chamber and the two are thermally connected by a heat pipe. In another aspect, combinations of the above energy sources can be used together. In another aspect, the system includes only one stage. In another aspect, the system includes a heat exchanger that captures energy in the intermediate fluid or the fluid leaving the system or both. In another aspect, a portion of the final concentrate leaving the system is recycled back to the system with the feed water to further increase its concentration. In another aspect, some or all of the concentrate leaving the evaporation chamber is recycled back to the evaporation chamber to help reduce scale formation. In another aspect, one or more heat pipes are installed perpendicular to the perforated plate. In another aspect, one or more heat pipes are installed at an angle other than ninety degrees to the perforated plate. In another aspect, the heat pipes diverge. In another aspect, the heat pipes have different lengths. In another aspect, the heat pipes are all of the same length. In another aspect, some or all of the system is constructed of titanium or a titanium alloy such as Ti-CP1 or Ti-CP2. In another aspect, some of all of the system is constructed of stainless steel alloys, nickel alloys, copper alloys, or other corrosion-resistant alloys. In another aspect, some or all of the system is constructed of conventional carbon steel or other metal alloys coated with a specific chlorofluorocarbon polymer (such as Teflon®) or various polymeric materials resistant to boiling temperatures and physiological saline or chemical environments.In another aspect, some or all of the system is constructed of a metal, ceramic, or cermet composite coating deposited on the walls of the container to prevent corrosion of the container. In another aspect, the hot plate forms some or all of the walls of the system. Systems with alternative steam injectors In some embodiments of the system, a steam injector / jet directs steam towards a heat pipe in the condensation chamber to enhance heat transfer between the steam and the heat pipe. In one embodiment (see FIG. 35), the injector... 180 is located at the top of the condenser 20 and directs a steam spray 295 across and along the heat pipe 25 is downward to help the condensate droplets leave the tube, making more surface available for heat transfer. In other embodiments, there may be multiple steam injectors to help distribute the steam throughout the condenser. In other embodiments, the injector may have multiple outlets to spread the steam across the heat pipe. In another aspect, the system operates at some or all of the vessel pressures at or above atmospheric pressure. In another aspect, the system operates at some or all of the vessel pressures under vacuum (less than atmospheric pressure) conditions. In another aspect, the system operates with one or more vessels below atmospheric pressure and one or more vessels at or above atmospheric pressure. In another aspect, the system has a deaerator. In another aspect, the system does not have a deaerator. In another aspect, the system has one or more demisters. In another aspect, the system does not have a demister. In another aspect, a pump moves the feed water or the concentrate or both between the stages. In another aspect, the feed water or the concentrate or both move between the stages by gravity. In another aspect, the feed water or the concentrate or both move between the stages using the pressure difference generated by the temperature difference between the stages. In another aspect, the purified water is delivered from the condensation chamber to the condenser one or more times. In another aspect, the purified water leaves each condensation chamber individually. In another aspect, in some condensation chambers the purified water is delivered between the condensation chambers and directly leaves other condensation chambers. In another aspect, the feed water is first fed into the evaporation chamber with the lowest temperature. In another aspect, the feed water is first fed into the evaporation chamber with the highest temperature. In another aspect, the feed water is fed individually into one or all of the evaporation chambers. In another aspect, the system includes means for steam recompression or steam reheating or both. In another aspect, the steam recompression system is mechanical vapor compression (MVC) or thermal vapor compression (TVC). In another aspect, the steam for recompression or reheating or both comes from the evaporation chamber with the lowest temperature. In another aspect, the steam for recompression or reheating or both comes from one or more of the intermediate temperature evaporation chambers. In another aspect, the steam for recompression or reheating is delivered to the condensation chamber with the highest temperature. In another aspect, the steam for recompression or reheating is delivered to one or more intermediate condensation chambers. In another aspect, the system includes one or more steam recompressors or reheaters between the evaporation chamber and the condensation chamber. In another aspect, the system has one condensation chamber that produces purified water. In another aspect, the system has multiple condensation chambers that produce purified water. In another aspect, the condensate from the energy input vessel is recycled to the steam generator. In another aspect, the condensate from the energy input vessel is combined with the purified water from one or more of the other stages. In another aspect, the stages are stacked vertically. In another aspect, the stages are arranged in parallel. In another aspect, some stages are stacked vertically and some are arranged in parallel. In another aspect, one or more of the stages are horizontally oriented.In another aspect, one or more of the stages are oriented at an angle to the horizontal. In another aspect, one or more of the containers are in the shape of a cylinder, or a sphere, or a cube or a cuboid or a conical solid or a pyramid. In another aspect, purified water or concentrate or both are used to preheat the feed water. In another aspect, the system does not have a pretreatment system. In another aspect, the system has a pretreatment system. In another aspect, the system has a post-treatment system. In another aspect, the system does not have a post-treatment system. In another aspect, the purified water or concentrate is flashed and the steam is delivered to a deaerator. In another aspect, the system includes a condenser for air cooling, water cooling or cooling with other chemicals for purified water or concentrate or both. In another aspect, one or more of the condensation chambers are below their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers are above their corresponding evaporation chambers. In another aspect, some of the condensation chambers are below their corresponding evaporation chambers and some of the condensation chambers are above their corresponding evaporation chambers. In another aspect, only some of the condensation chambers include one or more steam injectors. In another aspect, one or more of the steam injectors rotate. In another aspect, the evaporation chamber operates under pool boiling. In another aspect, the feed water or concentrate is sprayed onto the heat pipes in one or more of the evaporation chambers. In another aspect, the steam is the source of energy for the energy input container. In another aspect, the energy input container includes an electric heater, a fuel burner or a heat pipe that transfers heat from: electricity, steam, solar energy, chemical reactions, nuclear reactions, geothermal sources, molten salts, waste heat from industrial and other processes, flue gas, solid waste energy, heated heat transfer fluids, microwaves or the combustion of oil, hydrocarbons, biofuels, alcohols or natural gas, and wherein the energy input container is adjacent to or near the evaporation chamber and the two are thermally connected by a heat pipe. In another aspect, a combination of the above energy sources can be used together. In another aspect, the system includes only one stage. In another aspect, the system includes a heat exchanger that captures energy in the intermediate fluid or the fluid leaving the system or both. In another aspect, a portion of the final concentrate leaving the system is recycled back to the system with the feed water to further increase its concentration. In another aspect, some or all of the concentrate leaving the evaporation chamber is recycled back to the evaporation chamber to help reduce scale formation. In another aspect, one or more of the heat pipes are installed perpendicular to the perforated plate. In another aspect, one or more of the heat pipes are installed at an angle other than ninety degrees to the perforated plate. In another aspect, the heat pipes are splayed. In another aspect, the heat pipes are all installed at the same height. In another aspect, the heat pipes are installed at different heights. In another aspect, the heat pipes have different lengths. In another aspect, the heat pipes are all of the same length. In another aspect, the system includes annular heat pipes of different lengths. In another aspect, some or all of the system is constructed of titanium or a titanium alloy such as Ti-CP1 or Ti-CP2.In another aspect, some of all the systems are constructed of stainless steel alloys, nickel alloys, copper alloys, or other corrosion-resistant alloys. In another aspect, some or all of the systems are constructed of conventional carbon steel or other metal alloys coated with specific chlorofluorocarbon polymers (such as Teflon®) or various polymeric materials resistant to boiling temperatures and physiological saline or chemical environments. In another aspect, some or all of the systems are constructed of metal, ceramic, or cermet composite coatings deposited on the walls of the containers to prevent corrosion of the containers. In another aspect, the hot plate forms some or all of the walls of the system. Design of installing heat pipes in the process enclosure In some embodiments, heat pipes and / or thermosyphons can be used in applications where the heat pipes must pass through the walls of the process container or enclosure. The wall separates fluids, liquids, vapors, or combinations of liquids and vapors at different temperatures and pressures. In one embodiment, the enclosure is a pressure vessel. The pressure vessel can be made of metal or non-metal elements or a combination of both. Depending on the operating conditions, the pressure vessel can be characterized as fired or unfired. The pressure vessel can contain fluids, vapors, or a combination of two phases. The temperature and pressure inside the pressure vessel are different from the ambient temperature. In another aspect, the process enclosure is a metal or non-metal fluid conduit. The fluid can be a liquid, a gas, or a mixture of two phases. In another aspect, the wall can be the skin of an aircraft fuselage or the hull of a ship. The heat pipe mounting hardware has several functions, including (but not limited to) - 1. Mechanical support 2. Liquid-tight or gas-tight environmental sealing between opposite sides of the enclosure wall. 3. Preventing contact between different metals or alloys. The installation method is shown in a cross-sectional view in the drawings. Figure 36 shows the heat pipe. 25 and the perforated plate 115. The heat pipe can have a circular or non-circular cross-section. The heat pipe 25 can be installed perpendicular to the mounting surface (perforated plate 115) as shown in Figure 43, or installed at any angle ϴ with the mounting surface (perforated plate 115) as shown in Figure 44. Figure 37 shows the heat pipe 25, the wall, or the perforated plate 115, which has a machined groove to hold a flexible seal 445 held in place by a retainer 335. In another aspect, the flexible seal is held in place by a machined groove. Figure 38 shows the heat pipe held by a threaded insert 450 combined into the threaded wall or perforated plate 115. The threaded insert 450 holds the flexible seal 335. In another aspect, the threaded insert 450 is welded or brazed to the heat pipe 25. In another aspect, the threaded insert 450 is injection molded around the heat pipe 25. In another aspect, the threaded insert 450 is made of a non-conductive material to electrically isolate the heat pipe 25 from the wall or the perforated plate 115. In another aspect, the threads on the threaded insert 450 form a liquid-tight and gas-tight seal. FIG. 39 shows the heat pipe 455 electrically isolated from the perforated plate 115 by the insulating sleeve 25. The heat pipe 25 is sealed by one or more flexible seals 335. FIG. 40 shows another aspect of the heat pipe 25 held by the insulating sleeve 455. The insulating sleeve 455 is sealed by one or more flexible seals 335. The insulating sleeve 455 is held in place by a retainer 445 by means of a friction fit. In another aspect, the insulating sleeve 455 is threaded and held in place by a threaded retainer 445. FIG. 41 shows the heat pipe 25 held, sealed, and insulated by a sleeve 460 inserted into the perforated plate 115 or the wall. In another aspect, the sleeve 460 is molded around the heat pipe 25. In another aspect, the sleeve 460 is molded into an opening in the wall or the perforated plate 115. FIG. 42 shows the heat pipe 25 and the perforated plate 115 or the wall, which are coated with the same coating material 465 to eliminate the possibility of corrosion of the electrochemical cell. The coating material 465 can be applied by multiple processes, including (but not limited to) electroplating, painting, flame spraying, and vapor deposition. FIG. 45 shows the sleeve 460 fixed to the heat pipe 470, the metal connection includes (but is not limited to) welding, brazing, or soldering of various metals, alloys, or combinations of metals and alloys. In another aspect, the sleeve 470 is fixed to the heat pipe by a press fit with dimensional interference 25. In another aspect, the sleeve 470 is fixed to the heat pipe by a non-metallic material or mixture 475. The sleeve 470 is fixed to the wall or perforated plate 115 by a metal or non-metal connection or a press fit with dimensional interference as shown above. FIG. 46 shows a sleeve 470 having a conical or wedge-shaped outer surface, which is fixed to a similar conical container or wedge in the wall or perforated plate 115 by a friction fit. In another aspect, the conical sleeve 470 is fixed to the perforated plate 115 or wall by a metal or non-metal connection. The heat pipe 25 is fixed to the sleeve 470, which is part of FIG. 45, by any of the multiple methods listed. FIG. 47 shows a heat pipe 25 fixed to the perforated plate or wall 115 by a local deformation 480 of the perforated plate or wall 115. FIG. 48 shows a method of installing multiple heat pipes 25 in the perforated plate or wall 115. The perforated plate or wall 115, the flexible material sheet 485, and the fixing plate 490 are formed with coaxial holes. When the fixing plate 490 is fastened to the perforated plate or wall 115, compressing the flexible material, the heat pipe 25 is held by the flexible material 485. In another aspect, FIG. 49 shows a configuration of installing multiple heat pipes 25 on the mounting plate or pipe segment 495. The mounting plate or pipe segment includes one or several individual perforated plate sections 115, each section 115 containing one or multiple heat pipes. Each individual section can be independently used with fixing parts 500 combinations or disassemblies from a complete mounting plate assembly. The advantage of this geometry is that it is not necessarily required to remove the entire mounting plate or segment to service or replace individual heat pipes or groups of heat pipes. In another aspect, individual mounting plate sections may have a non-circular shape factor, such as rectangular, hexagonal, or elliptical, as required for the complete assembly. Systems with a hot plate FIG. 50 shows an embodiment of a system using a hot plate as a heat transfer device. A hot plate is a heat pipe with a cross-section that is not cylindrical or rectangular. A cylindrical hot plate with an annular cross-section can replace the wall of the stage vessel, thus eliminating the need for individual heat pipes and making cleaning easier. Feed water 45 enters the evaporation chamber 20 and is heated by energy entering through the hot plate wall 510. The energy is supplied by the demister from the previous evaporation chamber 30 of the steam 50 in the condensation chamber 35 on the hot plate wall for condensation supply. Purified water 65 leaves the condensation chamber. The plate 505 makes the condensation chamber 35 communicate with the evaporation chamber 20 Separation. In another aspect, a single hot plate forms a condensation chamber and extends into the corresponding evaporation chamber. The outer wall of the hot plate is made of insulating material, while the inner wall of the hot plate is made of heat-conducting material. In another aspect, the system operates at some or all container pressures at or above atmospheric pressure. In another aspect, the system operates at some or all container pressures under vacuum (less than atmospheric pressure) conditions. In another aspect, the system operates with one or more containers at less than atmospheric pressure and one or more containers at or above atmospheric pressure. In another aspect, the system has a degasser. In another aspect, the system does not have a degasser. In another aspect, the system has one or more demisters. In another aspect, the system does not have a demister. In another aspect, a pump moves the feed water or the concentrate or both between the stages. In another aspect, the feed water or the concentrate or both move between the stages by gravity. In another aspect, the feed water or the concentrate or both move between the stages using the pressure difference generated by the temperature difference between the stages. In another aspect, the purified water is delivered between the condensation chambers one or more times. In another aspect, the purified water leaves each condensation chamber individually. In another aspect, in some condensation chambers the purified water is delivered between the condensation chambers and directly leaves the other condensation chambers. In another aspect, the feed water is first fed into the evaporation chamber with the lowest temperature. In another aspect, the feed water is first fed into the evaporation chamber with the highest temperature. In another aspect, the feed water is fed individually into one or all of the evaporation chambers. In another aspect, the system includes means for steam recompression or steam reheating or both. In another aspect, the steam recompression system is mechanical vapor compression (MVC) or thermal vapor compression (TVC). In another aspect, the steam for recompression or reheating or both comes from the evaporation chamber with the lowest temperature. In another aspect, the steam for recompression or reheating or both comes from one or more of the evaporation chambers with intermediate temperatures. In another aspect, the recompressed or reheated steam is delivered to the compression chamber with the highest temperature. In another aspect, the recompressed or reheated steam is delivered to one or more intermediate condensation chambers. In another aspect, the system includes one or more steam recompressors or reheaters between the evaporation chamber and the condensation chamber. In another aspect, the system has one condensation chamber for producing purified water. In another aspect, the system has multiple condensation chambers for producing purified water. In another aspect, the condensate from the energy input container is recycled to the steam generator. In another aspect, the condensate from the energy input container is combined with the purified water from one or more of the other stages. In another aspect, the stages are stacked vertically. In another aspect, the stages are arranged in parallel. In another aspect, some stages are stacked vertically and some are arranged in parallel. In another aspect, one or more of the stages are horizontally oriented. In another aspect, one or more of the stages are oriented at an angle to the horizontal.In another aspect, one or more of the containers are in the shape of a cylinder, or a sphere, or a cube or a cuboid or a conical solid or a pyramid. In another aspect, purified water or concentrate or both are used to preheat the feed water. In another aspect, the system does not have a pretreatment system. In another aspect, the system has a pretreatment system. In another aspect, the system has a post-treatment system. In another aspect, the system does not have a post-treatment system. In another aspect, the purified water or concentrate is flashed and the steam is delivered to a deaerator. In another aspect, the system includes a condenser for air cooling, water cooling or cooling with other chemicals for purified water or concentrate or both. In another aspect, one or more of the condensation chambers are below their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers are above their corresponding evaporation chambers. In another aspect, some of the condensation chambers are below their corresponding evaporation chambers and some of the condensation chambers are above their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers include one or more steam injectors. In another aspect, none of the condensation chambers include one or more steam injectors. In another aspect, one or more of the steam injectors rotate. In another aspect, the evaporation chamber operates under pool boiling. In another aspect, the feed water or concentrate is sprayed onto a hot plate in one or more of the evaporators. In another aspect, the steam is the source of the energy input to the container. In another aspect, the energy input container includes an electric heater, a fuel burner or a hot plate that transfers heat from: electricity, solar energy, chemical reactions, nuclear reactions, geothermal sources, molten salts, waste heat from industrial and other processes, flue gas, solid waste energy, heated heat transfer fluids, microwaves or the combustion of oil, hydrocarbons, biofuels, alcohols or natural gas, and wherein the energy input container is adjacent to or near the evaporation chamber and the two are thermally connected by the hot plate. In another aspect, a combination of the above energy sources can be used together. In another aspect, the system includes only one stage. In another aspect, the system includes a heat exchanger that captures energy in the intermediate fluid or the fluid leaving the system or both. In another aspect, a portion of the final concentrate leaving the system is recycled back to the system with the feed water to further increase its concentration. In another aspect, some or all of the concentrate leaving the evaporation chamber is recycled back to the evaporation chamber to help reduce scale formation. In another aspect, some or all of the system is constructed of titanium or a titanium alloy such as Ti-CP1 or Ti-CP2. In another aspect, some of all of the system is constructed of a stainless steel alloy, a nickel alloy, a copper alloy or other corrosion-resistant alloy. In another aspect, some or all of the system is constructed of conventional carbon steel or other metal alloys coated with a specific chlorofluorocarbon polymer (such as Teflon®) or various polymer materials resistant to boiling temperatures and physiological saline or chemical environments. In another aspect, some or all of the system is constructed of a metal, ceramic or cermet composite coating deposited on the container walls to prevent container corrosion.In another aspect, the system includes a hot plate and a heat pipe as heat transfer devices. In another embodiment, the hot plate can be used as a wall of a nested configuration. A hot plate for increasing turbulence in the evaporation chamber FIG. 51 shows an embodiment of a system that uses a hot plate to increase turbulence in the evaporation chamber of the system. The boiling efficiency is increased due to the turbulence (higher Reynolds' number). This embodiment uses a corrugated shape to increase the Reynolds number in the evaporation chamber. A hot plate with a Reynolds number in 20 510, thus increasing the boiling efficiency. Flat or corrugated hot plates can also be stacked closer together than circular heat pipes, further increasing turbulence and the Reynolds number. The hot plate extends to the condenser Heat is captured with self-condensing steam in 35. In another aspect, grooves are incorporated into the hot plate to increase the surface area and thus increase the heat transfer efficiency. In another aspect, a sintered core is used on the outside of the hot plate to increase the surface area and the Reynolds number. In another aspect, the system operates at some or all container pressures at or above atmospheric pressure. In another aspect, the system operates at some or all container pressures under vacuum (less than atmospheric pressure) conditions. In another aspect, the system operates with one or more containers below atmospheric pressure and one or more containers at or above atmospheric pressure. In another aspect, the system has a degasser. In another aspect, the system does not have a degasser. In another aspect, the system has one or more demisters. In another aspect, the system does not have a demister. In another aspect, a pump moves the feed water or the concentrate or both between the stages. In another aspect, the feed water or the concentrate or both move between the stages by gravity. In another aspect, the feed water or the concentrate or both move between the stages using the pressure difference generated by the temperature difference between the stages. In another aspect, the purified water is delivered one or more times between the condensation chambers. In another aspect, the purified water leaves each condensation chamber individually. In another aspect, in some condensation chambers the purified water is delivered between the condensation chambers and directly leaves other condensation chambers. In another aspect, the feed water is first fed into the evaporation chamber with the lowest temperature. In another aspect, the feed water is first fed into the evaporation chamber with the highest temperature. In another aspect, the feed water is fed individually into one or all of the evaporation chambers. In another aspect, the system includes means for steam recompression or steam reheating or both. In another aspect, the steam recompression system is mechanical vapor compression (MVC) or thermal vapor compression (TVC). In another aspect, the steam for recompression or reheating or both comes from the evaporation chamber with the lowest temperature. In another aspect, the steam for recompression or reheating or both comes from one or more of the evaporation chambers with intermediate temperatures. In another aspect, the recompressed or reheated steam is delivered to the condensation chamber with the highest temperature. In another aspect, the recompressed or reheated steam is delivered to one or more intermediate condensation chambers. In another aspect, the system includes one or more steam recompressors or reheaters between the evaporation chamber and the condensation chamber. In another aspect, the system has one condensation chamber that produces purified water. In another aspect, the system has multiple condensation chambers that produce purified water. In another aspect, the condensate from the energy input container is recycled to the steam generator. In another aspect, the condensate from the energy input container is combined with the purified water from one or more of the other stages. In another aspect, the stages are stacked vertically. In another aspect, the stages are arranged in parallel. In another aspect, some stages are stacked vertically and some are arranged in parallel. In another aspect, one or more of the stages are horizontally oriented. In another aspect, one or more of the stages are oriented at an angle to the horizontal.In another aspect, one or more of the containers are in the shape of a cylinder, or a sphere, or a cube or a cuboid or a conical solid or a pyramid. In another aspect, purified water or concentrate or both are used to preheat the feed water. In another aspect, the system does not have a pretreatment system. In another aspect, the system has a pretreatment system. In another aspect, the system has a post-treatment system. In another aspect, the system does not have a post-treatment system. In another aspect, the purified water or concentrate is flashed and the steam is delivered to a deaerator. In another aspect, the system includes a condenser for air cooling, water cooling or cooling with other chemicals for purified water or concentrate or both. In another aspect, one or more of the condensation chambers are below their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers are above their corresponding evaporation chambers. In another aspect, some of the condensation chambers are below their corresponding evaporation chambers and some of the condensation chambers are above their corresponding evaporation chambers. In another aspect, one or more of the condensation chambers include one or more steam injectors. In another aspect, none of the condensation chambers include one or more steam injectors. In another aspect, one or more of the steam injectors rotate. In another aspect, the evaporation chamber operates under pool boiling. In another aspect, the feed water or concentrate is sprayed onto a hot plate in one or more of the evaporators. In another aspect, the steam is the source of the energy input to the energy input container. In another aspect, the energy input container includes an electric heater, a fuel burner or a hot plate that transfers heat from: electricity, solar energy, chemical reactions, nuclear reactions, geothermal sources, molten salts, waste heat from industrial and other processes, flue gas, solid waste energy, heated heat transfer fluids, microwaves or the combustion of oil, hydrocarbons, biofuels, alcohols or natural gas, and wherein the energy input container is adjacent to or near the evaporation chamber and the two are thermally connected by the hot plate. In another aspect, a combination of the above energy sources can be used together. In another aspect, the system includes only one stage. In another aspect, the system includes a heat exchanger that captures energy in the intermediate fluid or the fluid leaving the system or both. In another aspect, a portion of the final concentrate leaving the system is recycled back to the system with the feed water to further increase its concentration. In another aspect, some or all of the concentrate leaving the evaporation chamber is recycled back to the evaporation chamber to help reduce scale formation. In another aspect, one or more of the hot plates are installed perpendicular to the porous plate. In another aspect, one or more of the hot plates are installed at an angle other than ninety degrees to the porous plate. In another aspect, the hot plates are spread apart. In another aspect, the hot plates are all installed at the same height. In another aspect, the hot plates are installed at different heights. In another aspect, the hot plates have different lengths. In another aspect, the hot plates are all of the same length. In another aspect, some or all of the system is constructed of titanium or a titanium alloy such as Ti-CP1 or Ti-CP2. In another aspect, some of all of the system is constructed of a stainless steel alloy, a nickel alloy, a copper alloy or other corrosion-resistant alloy.In another aspect, some or all of the system is constructed of conventional carbon steel or other metal alloys coated with a specific chlorofluorocarbon polymer (such as Teflon®) or various polymeric materials resistant to boiling temperature and physiological saline or chemical environment. In another aspect, some or all of the system is constructed of a metal, ceramic, or cermet composite coating deposited on the container wall to prevent container corrosion. In another aspect, the hot plate forms some or all of the walls of the system. Scale inhibition, reduction, or removal Design for reducing water hardness using ultrafiltration (UF) or nanofiltration (NF) In some embodiments, the present invention can use the waste heat from the above water purification or concentration system to warm the feed water flow to the optimal membrane treatment temperature depending on the membrane temperature specification, and then further raise the temperature of the hardness-reduced feed water flow before it enters the water purification or concentration system. Embodiments include using NF to reduce or eliminate the addition of pretreatment water softening chemicals to the feed water flow. Embodiments include methods for capturing the waste heat of the water purification or concentration system to improve the purified water output of the water purification system or the efficiency of the concentration system. One embodiment is shown in FIG. 52. In this embodiment, the feed water flow... 45 is at a temperature below 40 °C when it flows or is pumped to the inlet heat exchanger 515. The heated feed water flow 95 leaves the inlet heat exchanger 515 at the optimal operating temperature of a given filter or process, and then enters the UF or NF system 520 at the optimal operating temperature. Hardness ions are captured in the UF / NF system and eliminated in the concentrate waste stream 530 flowing into the waste concentrate discharge 525. The hardness-reduced feed water 535 flows into the waste concentrate heat exchanger 515, where the temperature of the treated feed water is further raised by energy transfer from the water purification or feed concentration system or the final concentrate fluid 55. The high-temperature UF / NF-treated feed water flow 540 enters the water purification or concentration system 545. The system output includes the final concentrate stream 55 and the purified water stream 65. In a second embodiment, the final concentrate stream 55 from the water purification or concentration system is pumped or flows through the waste concentrate heat exchanger 515 and reaches the temperature bypass control valve 550. The temperature bypass control valve The setting of 550 is controlled by the temperature probe in 515 via the inlet heat exchanger in 515 555 to transfer the hot concentrate stream 55 through the inlet heat exchanger 515 to obtain the feed water stream at the optimal temperature of 45 (35 - 40 °C). Once the concentrate stream 55 is passed through the inlet heat exchanger 515, the stream is directed to the concentrate outlet 530. Any concentrate that does not flow through the inlet heat exchanger 515 is delivered to the concentrate outlet 530. In another aspect, an alternative method uses the purified water stream 65 instead of the waste heat in the final concentrate stream 55. In another aspect, if there is a degasser, the UF / NF filtration system is located between the water purification or concentration system preheater and the degasser, or if there is no degasser, it is located between the water purification or concentration system preheater and the next stage. In another aspect, when the temperature of the incoming stream is 40 °C or greater than 40 °C, a heat exchanger or other heat transfer mechanism is used to reduce the temperature of the feed water stream to 40 °C or less. Once the feed water stream is passed through the UF / NF filtration system 520, the treated feed water 535 is passed through the heat exchanger 515 to increase the temperature of the treated feed water before it enters the water purification or concentration system 540 in 545. In another aspect, the inlet heat exchanger The energy input of 515 can be provided by other energy sources, such as solar energy, geothermal energy, and waste heat from other sources. Self-cleaning and in-situ cleaning methods Self-cleaning medium The evaporation chamber may also include a self-cleaning medium including a plurality of particles. In such embodiments, the intermediate concentrate has one or more openings with dimensions that do not permit the particles to pass through the intermediate concentrate outlet. The openings may further have a shape that is not complementary to the shape of the particles. The particles may be generally spherical, or may be other shapes selected for optimal cleaning efficiency. The particles may also include features that allow the particles to be agitated substantially continuously by the boiling of water in the evaporation chamber. The features may be, for example, specific gravity, size, morphology, population number, and the like. The particles may have a selected hardness such that the hardness allows the evaporation chamber and the heat transfer device to be rubbed by the particles, and substantially does not erode the particles or the evaporation chamber or the heat transfer device. In addition, the particles may be composed of ceramic, metal, glass, or stone. The specific gravity of the particles may be greater than about 1.0 and less than about 8.0. FIG. 53 shows an embodiment using such particles, where the particles 560 are enclosed within a concentric perforated cylinder 25 surrounding each heat pipe 565. The heat pipes extend into the intermediate concentrate 20 in the evaporation chamber In another aspect, the evaporation chamber includes a self-cleaning medium for disturbing the accumulation of deposits in the evaporation chamber, at least in the region close to the heat pipe. In another aspect, the medium includes a plurality of particles. In another aspect, the particles are generally spherical. In another aspect, the particles include features that allow the particles to be agitated substantially continuously by the boiling of water in the evaporation chamber. In another aspect, the features are selected from the group consisting of specific gravity, size, morphology, number of the group, and composition. In another aspect, the particles have a selected hardness, where the hardness allows the evaporation chamber to be rubbed by the particles, and substantially does not erode the particles or the evaporation chamber. In another aspect, the particles are composed of ceramics, metals, glass, stones, or combinations of such materials. In another aspect, the specific gravity of the particles is greater than about 1.0 and less than about 8.0. In another aspect, the specific gravity of the particles can be between about 2.0 and about 5.0. The self-cleaning medium can be selected from any of a variety of suitable alternatives. Such alternatives include glass or ceramic beads or balls, stones, synthetic structures in any of a variety of shapes, and the like. In each case, the characteristics of the self-cleaning medium are selected such that the individual particles of the self-cleaning medium will be displaced by the agitation of boiling water, but such displacement will be overcome by the physical characteristics of the self-cleaning medium, so that each particle will fall again on the side of each heat pipe and the bottom of the evaporation chamber, hitting and removing any deposits or scale. For example, a self-cleaning medium with a relatively high specific gravity but a relatively small surface / volume ratio can act in a manner substantially equivalent to a second self-cleaning medium with a relatively low specific gravity but a relatively high surface / volume ratio. In each case, those skilled in the art can select a combination of morphology and composition to obtain the desired results. In some embodiments, alternative methods of self-cleaning are used, such as applying ultrasonic energy. Another consideration in the design selection of the self-cleaning medium is its hardness. Generally, the hardness should be substantially equivalent to the hardness of the material constituting the evaporation chamber. This allows the continuous use of the self-cleaning medium for a long period of time without significantly eroding the medium or the walls or bottom of the evaporation chamber. In some embodiments, where the heating element of the evaporation chamber is located inside the chamber, such as in the case of having a heat pipe, the hardness and other characteristics of the self-cleaning medium can be selected to avoid erosion or other damage to the heating element as well as the evaporation chamber itself. Some embodiments provide broad-spectrum water purification that is fully automated and does not require cleaning or user intervention for extremely long periods. For example, the systems disclosed herein can operate for 1, 2, 4, 6, 8, 10, or 12 months or longer without user control or intervention. In some embodiments, the system can operate automatically for 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 years or longer. In other cases, the system can be cleaned one stage at a time or multiple stages at a time, in such a way that the entire water treatment system does not necessarily have to stop operating for maintenance. In another aspect, the system does not require cleaning for at least about two months. In another aspect, the system does not require cleaning for at least about one year or longer.Alternatively, the system may be cleaned relatively frequently in one or more stages at a time, such that the entire water treatment system does not necessarily have to be stopped for maintenance. One or more stages are taken out of service and cleaned in place while other stages remain in operation. Some examples are illustrated in FIGS. 54 and 55. In a multi-stage evaporation system, each stage has different temperatures or different concentrations of chemicals or both. A high concentration of salts in water can increase the rate of formation of scale such as calcium carbonate, calcium sulfate, or magnesium silicate. Different temperatures can change the type of chemical precipitation, the specific polymorph of a crystal, or the degree of hydration of a compound. Different temperatures and chemical compositions can result in different corrosion rates for parts of the system. Thus, the frequency and type of maintenance may be different in each stage. Embodiments of the present invention provide systems and methods for multi-stage water purification or feed water concentration systems where a single chamber or multiple chambers may be under repair while others remain in operation. In one embodiment, the water purification or feed water concentration system includes two or more stages. 90, each stage containing a condensation chamber 35 and an evaporation chamber 20, one or more heat transfer devices including (but not limited to) heat pipes 25, pipes, rods, plates, or heat exchangers, pipes for transferring fluid between stages, pumps for pumping fluid between stages if present, a series of valves for directing fluid to different locations in the system, a set of sensors including (but not limited to) sensors for temperature, pressure, liquid level, conductivity, and control systems for operating pumps, valves, and other drive devices common in chemical equipment. A single stage or multiple stages may be under repair by redirecting any vapor supplied to the condensation chamber of that or those stages into the condensation chambers of one or more different stages and redirecting any liquid supplied to that or those stages into the condensation chambers or evaporation chambers of one or more different stages. In some embodiments, the redirection of flow may be accomplished by manually operating valves It is implemented by 130. In other embodiments, the redirection of the flow can be achieved by controlling system valves. Adjustment and in-situ cleaning As previously mentioned, water purification or feed water concentration technologies are hindered in their effectiveness by the formation of scale. In membrane-based processes, this scale can lead to membrane fouling. In heat-based water purification or feed water concentration methods, the formation of scale creates additional resistance to the heat flow in heat transfer devices such as heat exchangers, hot plates, heat pipes, and other devices. The most common scale is the inorganic salts of calcium and magnesium deposited on the inner surface of the device. The formation of such scale can be enhanced due to the increased concentration of constituent ions during water evaporation, or such formation can be enhanced due to the change in solubility of some chemical species when the temperature of the aqueous solution changes, or both of these effects. Two common types of scale in industrial water streams are calcium sulfate and calcium carbonate. To avoid problems associated with scale formation, pretreatment steps are required, including one or more of the following steps: flocculation, sedimentation, filtration, ion exchange resins and nanofiltration, centrifugation, and other steps. Alternatively, the reduction of the scaling rate can be achieved by adding chelating agents such as EDTA or crystal growth modifiers such as polyacids. These steps increase the capital and operating costs in wastewater treatment operations. Water purification technologies that reduce or eliminate pretreatment steps are highly desirable. Embodiments of the present invention provide an improved method for operating a water purification or feed water concentration system without pretreatment even in feed water streams that are prone to scale formation, such as those with high levels of ions (such as calcium, magnesium, carbonate, bicarbonate, silicate, and sulfate). Embodiments of the present invention provide a method for removing scale from the surfaces of such heat transfer devices, including (but not limited to) heat pipes, pipes, rods, plates, or heat exchangers, without having to physically access the surfaces of the heat transfer devices, thus eliminating the need to open the containers containing the devices. In some embodiments, the method includes an adjustment step in which a thin layer is deliberately formed on the surface of a heat transfer device such as a heat pipe, pipe, or plate; the method also includes the step of routinely operating the heat transfer device or devices, in which scale can form on top of the thin layer; the method also includes an in-situ cleaning step in which the thin layer is removed chemically, causing any scale formed on top of the thin layer to fall off. In some embodiments, the method includes heat management to mechanically reduce scale. Heat transfer devices and scale typically have different coefficients of thermal expansion. For example, if a cold mixture is added to the system, the heat transfer device and the scale contract by different fractions of their original volumes. The adhesion of the scale to the surface of the heat transfer device is weakened, and the mechanical stress in the scale is increased, resulting in the fracture of the scale and the re-exposure of the surface of the heat transfer device. Mechanical energy can be applied to the heat transfer device to enhance scale fracture. A heat fluid can be supplied to the condenser side of the heat transfer device to increase the heat gradient along the device. In some embodiments, the method includes a combination of an adjustment step, reducing scale by heat management, and in-situ cleaning.Embodiments of the present invention provide a water purification or feed water concentration system, which may include pretreatment, a deaerator, a preheater, one or more evaporation chambers and demisters, one or more product condensation chambers, inlets and outlets for liquid and gas flows, a control system, one or more heat recovery units, equipment for regulating and in-situ cleaning procedures, and equipment for removing solids. FIG. 56 is a diagram of the adjustment, fouling, and in-situ cleaning steps on a heat transfer device in a water purification and feed water concentration system. In a first aspect, as shown in FIG. 56, the method is carried out on a heat transfer device in a water purification system... ...in the evaporation chamber of 25 (heat pipes, heat exchangers, hot plates, and others). ...a calcium carbonate thin layer is deliberately formed on the 20 side surface. ...starting at 305. This is called the adjustment step. In some embodiments, the method can be used on components that are prone to scale formation, such as parts of preheaters, deaerators, demisters, and heat exchangers. The layer ...305 is thin enough, i.e., it only imposes a small resistance on the heat flow in and out of the heat transfer device ...25. In one aspect, the thickness of the layer ...305 is less than one nanometer. In another aspect, the thickness of the layer ...305 is less than 10 nanometers. In another aspect of pH, it is less than 100 nanometers. In another aspect, it is less than 1 micron. In another aspect, it is less than 10 microns. In another aspect, it is less than 100 microns. In another aspect, it is less than 1 millimeter. In another aspect, it is less than 1 centimeter. The layer ...305 can be formed by adding an aqueous solution containing calcium and carbonate ions and evaporating water from this solution, so that the product of the molar concentrations of calcium and sulfate ions is higher than the solubility product, and a solid phase is formed. The evaporation of water can be achieved by supplying heat to the aqueous solution, for example (but not limited to) by feeding steam into the condenser side of the heat transfer element ...25 ...35. In another aspect, other heat transfer mechanisms, or heat transfer fluids, or combinations of fluids can be used, and these fluids include (but not limited to) hot air, water, oil, silicone, flue gas, and molten salt. In another aspect, evaporation can be achieved by applying a vacuum to the evaporation chamber side of the stage. In another aspect, evaporation can be achieved by combining heat and vacuum. In another aspect, the calcium carbonate layer ...305 can be formed by is formed by precipitation from an aqueous solution in the evaporation chamber side of 25, which occurs when the product of the molar concentrations of calcium and sulfate ions is higher than the solubility product. This can be achieved by the following combinations: adding a calcium-containing chemical species to the solution, adding a carbonate-containing chemical species to the solution, adding a bicarbonate-containing chemical species and a base to the solution so that the pH value of the solution increases to a range where the carbonate-bicarbonate equilibrium starts to shift towards carbonate, adding a base to increase the pH value and feeding carbon dioxide gas into the chamber, and thus absorbing it in the solution. In another aspect, the thin calcium carbonate layer 305 can be formed by a combination of two methods: precipitation and evaporation after adding chemicals to form a solid. After forming the thin calcium carbonate layer 305, a water treatment or water supply concentration process (conventional operation) can usually be carried out until the formation of scale 300 reaches the maximum allowable thickness of the process, which can be determined by the technical and economic analysis of various water purification technologies, or until the scale needs to be removed for other reasons. To remove the scale, an acidic aqueous solution is supplied to the evaporation chamber. This solution penetrates through the pores and cracks in the scale 300 and reacts with the thin calcium carbonate layer 305. After the thin layer 305 dissolves, the scale 300 usually physically separates from the surface of the heat transfer device in fragments, so it no longer offers resistance to the heat flow. The scale 300 fragments can be collected at the bottom of the container or left as a suspension in the liquid. The acidic solution can contain one or more of the following acids: citric acid, hydrochloric acid, nitric acid, formic acid, hydrobromic acid, and other acids stronger than carbonic acid. In one aspect, the pH value of the acidic solution is less than 7. In another aspect, it is less than 6. In another aspect, it is less than 5. In another aspect, it is less than 4. In another aspect, it is less than 3. In another aspect, it is less than 2. In another aspect, it is less than 1. In another aspect, the selected acid or mixture of acids is slowly dosed into the aqueous solution, and the evaporation chamber is filled with the feed solution during normal operation. Alternatively, the water supply can be partially or completely discharged from the container before adding the in-situ cleaning solution. In some aspects, the heat transfer device can be dried before adding the in-situ cleaning solution. In another aspect of the present invention, a similar thin layer 305 can be formed from one or more water-insoluble carbonates such as magnesium carbonate, strontium carbonate, barium carbonate, and other carbonates. As described above for the calcium carbonate layer, this layer 305 can be formed by evaporation and crystallization, precipitation, or a combination of both. After normal operation, the scale 300 can be removed by the same in-situ cleaning process described above. In another aspect of the present invention, a source of carbonate ions is added to the feed water containing sulfate anions to promote the formation of carbonate-based scale rather than sulfate-based scale. The source of carbonate can be a carbonate, such as sodium carbonate (soda ash). In another aspect, a combination of bicarbonate and base, such as sodium bicarbonate (baking soda), can be added to raise the pH high enough to convert most of the bicarbonate ions to carbonate ions. The addition of carbonate can result in the formation of solid carbonates, such as calcium carbonate, magnesium carbonate, strontium carbonate, and others. In this case, the resulting solids can be separated from the feed water by filtration, sedimentation, centrifugation, or any other standard separation technique. The resulting aqueous solution can then be fed into a water treatment system, such as an evaporation chamber. As the solution concentrates due to water evaporation, the precipitated carbonate scale (magnesium carbonate, calcium carbonate, and strontium carbonate) will occur before any of the corresponding sulfate scale precipitates. As described above, the scale can be removed by the action of an acidic aqueous solution supplied to the evaporation chamber. In another aspect of the present invention, the feed stream containing sulfate anions is treated with a source of carbonate ions within the distillation system before water removal by evaporation begins. The resulting carbonate precipitate is not separated from the aqueous solution. In fact, these solids are suspended in the feed water circulated through one or more stages in the distillation system and leave the system with the concentrated stream. In one embodiment, an excess of carbonate ions is added, so that all the precipitate forms at the beginning of the distillation system, and thus scale formation on the surface of the heat transfer device is avoided. In another aspect, the minimum amount of carbonate ions is added so that when water evaporates in the system, carbonate scale is preferably formed rather than sulfate scale. As described above, these carbonate scales can be removed by treatment with an acidic solution. In another aspect, only a small amount of carbonate ions is added so that the scale formed has calcium carbonate regions embedded in the scale (mainly composed of sulfate); these carbonate regions can act as break points when treated with an acid solution as described above. In another aspect, carbonate ions are present in the feed stream. In another aspect, bicarbonate ions are present in the feed stream and increase the pH to shift the bicarbonate / carbonate equilibrium towards the second species. As shown in the above description, the methods presented in this section can be applied to systems where the heat transfer device is a heat pipe. However, this method can also be applied to other types of heat transfer devices, such as annular heat pipes, thermosyphons, hot plates, heat exchangers, falling film evaporators, rising film evaporators, crystallizers, multi-effect distillation systems, multi-stage flash distillation systems, reverse osmosis systems without feed water preheating, etc. Multiple degassers - one or more are cleaned at a time Evaporation-based water purification and feed water concentration techniques separate clean water from contaminated water by releasing vapor from the feed water by adding thermal or mechanical energy. The feed water to be treated can contain chemical species with relatively low vapor pressures, such as ammonia or volatile organic compounds that can evaporate simultaneously with steam from the feed water, and thus contamination of the product water produced by gas condensation can be aborted.Referring to FIG. 57, an embodiment of the present invention provides a system and method for removing volatile species from a water feed prior to purification of the water feed by a thermal process. In a first aspect, the feed water... 45 or pretreated feed water 80 is passed through a first of two degassing chambers positioned in parallel in the process flow, while a second degassing chamber is idle. In another aspect, more than two degassing chambers 15 may be in parallel or in series. At least one chamber is idle or removed from the process flow for cleaning, while the other or others remain in the system for degassing. The chamber 15 may be a packed tower, a tower with multiple discrete plates, one of the stages in a multi-stage evaporator, an empty tower with nozzles, or any other vessel that brings a liquid stream into contact with a gas stream. The water to be treated 15 is fed into the vessel at one location, and a gas stream 45 / 80 is fed into the vessel at the same or another location. The gas 100 may be steam, air, nitrogen, argon, methane, a mixture of such gases, or any other non-condensable gas that is condensed from the product water downstream of the degasser in the evaporation chamber. In one aspect, the gas 100 is fed in at room temperature. In another aspect, the gas 100 is preheated to a temperature above ambient. In another aspect, the gas 100 is preheated to a temperature above the boiling point of the feed water 100 is preheated to a temperature above the boiling point of the feed water 45 / 80. The feed water 45 or pretreated feed water 80 and the gas 100 come into contact as they flow through the degassing chamber 15, at least a portion of their path being inside the degasser. In one aspect, the gas 100 and the feed water 45 / 80 follows a parallel path. In another aspect, it has a convective flow. In one aspect, the liquid first contacts one or more gases (such as air, to remove volatile organic compounds), and then the liquid is contacted with another gas (such as steam, to remove air from the liquid). In one aspect, two or more gases are each used for different parts of a degasser. In another aspect, two or more gases are each used in different degassers. In another aspect, only one gas is used in all degassers. Feed water 45 or pretreated feed water 80 and the gas The flow of 100 can be switched from the first chamber to the second or additional chamber at any time, thus leaving the first chamber idle for cleaning or maintenance. During operation, the flow of feed water and gas can be directed to any one of two or more degassing chambers, thus leaving the other degassing chambers idle for cleaning or maintenance. In another aspect, the first chamber and the second chamber or additional chamber have different sizes or designs, so that the system is preferably suitable for treating various feed waters with different types or concentrations of volatile compounds. In another aspect, the injection points in the degasser can vary with the type and concentration of volatile compounds in the feed water. This can be done, for example, to reduce the energy consumption of the degassing step. Thermal and mechanical shock cleaning As previously discussed, water purification and feed water concentration technologies are hindered in their effectiveness by the formation of scale. In membrane-based processes, this can lead to membrane fouling. In heat-based processes, the formation of scale creates an additional resistance to the heat flow in heat transfer devices such as heat exchangers, hot plates, heat pipes, and other devices. Removing scale is expensive and slow. Referring to FIG. 58, an embodiment of the present invention provides a method for removing scale from the surfaces of heat transfer devices, including (but not limited to) heat pipes, pipes, rods, plates, or heat exchangers, without having to physically reach the surface of the heat transfer device, so that it is not necessary to open the container containing the device. Heat transfer device 25 and the scale 300 generally have different coefficients of thermal expansion, and when the mixture is added to the system, they contract different fractions of their original volume. The scale 300 and the heat transfer device The adhesion of 25 to the surface is weakened, and the mechanical stress of the scale is increased, resulting in the scale cracking and exposing the surface of the heat transfer device again. Referring to FIG. 58, the first method starts by feeding a liquid, a mixture of liquids, or a solid and a mixture of liquids into a chamber containing a heat transfer device 25 with scale 20 in such a way that the added liquid or mixture contacts the surface of the scale 300. The temperature of the liquid or mixture is less than that of the heat transfer device 25 and scale A temperature of 300. In one aspect, the temperature is less than 10°C. In another aspect, the temperature is less than 0°C. In another aspect, the temperature is less than -40°C. In another aspect, the temperature is less than -75°C. The following table lists several possible mixtures and their temperatures. In another aspect, after generating the thermal shock described above, mechanical energy is applied to the heat transfer device 25 To enhance scale 300 ruptures. Apply energy in the form of vibration, tapping, or use any other suitable process, such as a sound that generates resonance (close to the natural vibration frequency of the scale). In another aspect, while adding a cold liquid or mixture as described above, heat is provided to the heat transfer device The condenser of 25 35 side. This promotes the flashing of the mixture, generating a local rapid pressure swing that provides mechanical energy to cause the scale 300 to rupture. In another aspect, a cold liquid or mixture is added to the heat transfer device The condenser of 25 35 side. In another aspect, a cold liquid or mixture is added to the heat transfer device The condenser of 25 35 side, and the heat transfer fluid is fed into the heat transfer device The evaporation chamber of 25 20 side. In other embodiments of the present invention, the scale is removed by a combination of adjustment, in-situ cleaning, and thermal and mechanical treatments as described in the 'Adjustment and In-Situ Cleaning' section and shown in Figure 56. Table 7 - Typical Cooling Mixtures Robot cleaner Referring to Figure 59, an embodiment of the present invention provides a method for removing scale from the surfaces of heat transfer devices, including (but not limited to) heat pipes, without having to open the container containing the heat transfer devices 25, pipes, rods, plates, or heat exchangers. In a first aspect, the device for removing scale 310 circulates between heat transfer devices 25, which include (but are not limited to) heat pipes, pipes, rods, plates, or heat exchangers. The device 310 makes physical contact with the scale. In one aspect, the device 310 has an attachment for transferring mechanical energy to the fouled surface, such as (but not limited to) a rotary brush, a vibrating motor, an ultrasonic horn, a speaker that generates a sound with a frequency close to the natural vibration frequency of the scale, or a combination of such attachments. In another aspect, the device 310 moves along the surface of the heat transfer device, dragging one or more sharp tips that contact the water scale. In one aspect, the tips are made of a material softer than the surface of the heat transfer device 25 so as not to scratch it. In another aspect, the device 310 applies pressure to the tips by means of springs, hydraulic pistons or similar devices. In another aspect, the applied pressure can be controlled, for example, by changing the pressure of the hydraulic fluid. In another aspect, the device 310 when placing the heat transfer device The interior of the container of 25 moves autonomously along a pre-programmed path. In another aspect, an external signal is sent to the device to control its trajectory. In another aspect, the device is physically connected to a moving mechanism, such as a rod, cable or similar umbilical cable, and the mechanism is driven by one or more electric motors that may be located inside or outside the container. In another aspect, a plate having an orifice moves along a heat transfer device inside the orifice. In one aspect, the periphery of the orifice has a brush, tip or other structure that can break the mechanical integrity of scale. In another aspect, the plate vibrates. Coated heat pipes are extremely effective heat transfer devices for heat-based water purification systems. Heat pipes are also extremely effective heat transfer devices when used to improve the performance of non-heat-based water purification systems such as filtration systems, osmosis systems and other membrane-based systems. The materials of the structures of commercially available heat pipes are selected based on heat transfer characteristics and ease of manufacture, but generally they do not meet the performance requirements of water purification, such as corrosion resistance or anti-scaling ability. Embodiments of the present invention provide systems and methods for modifying the surface of heat pipes to be used for water purification. In a first aspect, a coating is deposited on the surface of the entire heat pipe. In one aspect, the function of the coating can be to increase corrosion resistance in aqueous solutions having high salt concentration, high pH, low pH, high oxidation potential or any combination thereof. In another aspect, the function of the coating can be to promote the formation of bubbles during boiling. In another aspect, the function of the coating can be to increase the hydrophobicity of the surface to enhance the condensation of steam on the surface. In another aspect, for example, if the nature of the coating is such that solids do not adhere to it, the function of the coating can be to avoid the formation of scale. In another aspect, the coating can have more than one of the functions listed above. The coating can be deposited by electroplating, vapor deposition, thermal or plasma spraying, painting, coating or any other suitable method. In another aspect, only a part of the heat pipe surface is coated. The purpose of the coating can be one or more of the functions mentioned above. For example, the evaporation chamber part of the heat pipe in a water purification or feed water concentration system can be coated to increase corrosion resistance. As another example, the condenser part of the heat pipe in a water purification system can be coated to increase the condensation rate. In another aspect, different regions of the heat pipe can be coated with different materials to achieve different purposes. For example, the evaporation chamber part of the heat pipe in a water purification or feed water concentration system can be coated to increase corrosion resistance, and the condenser part of the same heat pipe can be coated to increase the condensation rate. In another aspect, the coating can be applied to the container wall, one or more surfaces of the heat pipe mounting plate, inserts or any other part for mounting the heat pipe on the plate, baffles, screens or any other part in the water purification or feed water concentration system that comes into contact with feed water or product water. In another aspect, the coating can be applied to other heat transfer devices, including radiators, annular heat pipes, flat heat pipes, pulsating heat pipes and others.Electric Bias on Heat Pipe Referring to FIGS. 60 and 61, an embodiment of the present invention is shown that provides a system and method for a heat pipe-based water purification or feed water concentration system, where scale formation on the surface of the heat pipe is slowed or terminated by applying an electric bias on the surface of the heat pipe. In one aspect, on the surface of the heat pipe... A positive voltage is generated between the surface of 25 and another point in the system, such as the container wall or one or more electrodes 315 placed in the aqueous solution (feed water) being purified. An electrical insulator 320 can be used to mount the heat pipe. The positive charge on the heat pipe surface attracts negatively charged ions in the solution, thereby generating an anion-rich layer around the heat pipe. When cations reach near the heat pipe, due to the high density of anions, the possibility of homogeneous precipitation (forming crystals in the suspension) rather than heterogeneous precipitation of scale on the surface of the heat pipe is high. In another aspect, different ranges of voltages can be used depending on the characteristics of the feed water and the material of the container structure. In another aspect, different configurations of electrodes can be used. In another aspect, a positive voltage can be applied to some heat pipes to attract anions and a negative voltage can be applied to other heat pipes to attract cations. In another aspect, a voltage can be applied to a system using other types of heat devices including hot plates, annular heat pipes, pulsating heat pipes, flat heat pipes, and radiators. Heat Pipe-Based Systems Using Heat Pipes in MSF and MED in Alternative Configurations Conventional MSF and MED designs use hollow pipes for heat transfer, where one fluid flows inside the pipe and another fluid surrounds the pipe, usually sprayed on the pipe assembly (pipe bundle). A heat pipe as a sealed system can operate more effectively with different means of dispersing the fluid around the heat pipe or heat pipe bundle. Referring to FIG. 62, the left figure is a partial reproduction of a figure from U.S. Patent 9,393,502 B1 of MSF, which is incorporated herein by reference in its entirety, and the notes on alternative configurations are described below. The right figure is a partial reproduction of a figure from U.S. Patent 9,309,129 B1 of MED, where the notes on alternative configurations are described below. One embodiment relates to using a steam ejector or an array of ejectors from a demister 30 to direct the steam flow in the condensation chamber 35 to the heat pipe 25 array. The improvement is to direct the steam flow to the heat pipe 25 bundle to improve the vapor-to-metal heat transfer coefficient, for example, by reducing the gas boundary layer at high vapor linear velocities. An embodiment relates to improving the configuration of the condensation chamber for steam condensation in a pipe bundle (circular, not rectangular). An embodiment relates to a cylindrical condenser chamber surrounding a heat pipe bundle, which is more effective than the rectangular chamber shown in existing patents. Referring to FIG. 62 (left figure), an embodiment relates to a non-immersed evaporation chamber in the configuration of vertical heat pipes 25 35, including a spray nozzle of the heat pipe 345 film boiling on the vertical bundle 25. Other embodiments include systems made using radiators, annular heat pipes, pulsating heat pipes, and flat heat pipes. Freeze purification When an aqueous solution is frozen at a slow rate, the dissolved species and suspended solids preferably remain in the solution. Thus, the formed ice layer can be separated and remelted to obtain clean water. Embodiments of the present invention provide systems and methods for separating water from a mixture by freezing, where the heat pipe acts as a heat transfer device. In a first aspect, referring to FIG. 63, a heat pipe 25 is used as a heat transfer device to freeze a mixture of water 45 and other chemical species slowly. One end of the heat pipe is brought into contact with the water mixture 45, and the other end of the heat pipe is brought into contact with a fluid or surface having a temperature lower than the melting point of water, which is lower than the melting point of pure water, and the water is in a mixture with the solute concentrate. The two ends are separated by a plate 115. In one aspect, the cold end of the heat pipe is kept cold by means of a vapor-based refrigerator, a thermoelectric refrigerator, using ice, and using any other fluid such as cold air. In another aspect, the water mixture is periodically discharged and the ice 325 on the heat pipe is melted to recover purified water 65. In another aspect, the melting of the purified water is accelerated by applying heat to the other end of the heat pipe. In another aspect, the ice is only partially melted to detach it from the heat pipe, and then collected in the form of a liquid-solid mixture. In another aspect, the ice is periodically scraped off the heat pipe mechanically. In another aspect, the ice is continuously scraped off the heat pipe. In another aspect, the hot end of the heat pipe is in close contact with or welded to a flat or circular surface forming an ice shell. In another aspect, the plate is continuously moved, such as rotated. In one aspect, the aqueous solution is wastewater. In another aspect, it is seawater. In another aspect, it is a mixture produced by biomass fermentation. Using a heat pipe to preheat water for ultrafiltration and nanofiltration Ultrafiltration (UF) and nanofiltration (NF) membrane filtration processes are proven water hardness reduction processes (see, for example, Izadpaneh / Javidnia, Water 2012, 4, 283-294). Both membrane filtration processes most effectively remove water hardness ions (such as Ca++ and SO4-) at a slightly higher temperature between 35 °C and 40 °C. The present invention can use a heat pipe to capture heat from a single source or from multiple sources, and transfer the heat to warm the incoming liquid stream to the optimal membrane treatment temperature (roughly 15 °C to 80 °C, depending on the membrane temperature specifications). Referring to FIG. 64, in some embodiments, one or more heat pipes a portion of its length (the hot portion) of 25 570 is exposed to a heat source, and different portions of its length (cold portions) 575 are exposed to cooler feed water 45 flows. Heat transfers from the heat source 580 (hot portion) to the feed water 45 flows (cold portion) to produce a preheated feed water stream to be fed into a nanofiltration or ultrafiltration system 540. The heat pipes are installed on a perforated plate 585 that is part of a housing 115. The heat pipes 25 can be installed in any orientation (vertical, horizontal or any other angle). The lengths of the heat pipes can vary. The lengths of the heat pipes in the hot portion can vary. The lengths of the heat pipes in the cold portion can vary. The installation orientation of the heat pipes in the hot portion can be the same as or different from the installation orientation of the heat pipes in the cold portion. For the hot portion or the cold portion or both, the housing can be closed and pressurized or open to the atmosphere. The cold portion can be adjacent to the hot portion, or the two portions can be separated. The heat can be provided by a single or multiple sources, i.e., a hot fluid or gas, steam, hot water, flue gas, exhaust gas, thermal fluid, geothermal fluid or gas, molten salt, an electric heat source, solar heating captured via radiation or photovoltaics or a combination of such sources. Using heat pipes to preheat water for a reverse osmosis (RO) system The reverse osmosis membrane filtration process is a proven water hardness reduction process (see e.g. Izadpaneh / Javidnia, Water 2012, 4, 283 - 294). The RO membrane filtration process most effectively removes water hardness ions (such as Ca++ and SO4-) at a slightly elevated temperature between 35 °C and 40 °C. The present invention can use heat pipes to capture heat from a single source or from multiple sources, and transfer the heat to warm a liquid feed water stream to an optimal membrane treatment temperature (roughly 15 °C to 80 °C, depending on the membrane temperature specifications). Referring also to Figure 64, in some embodiments, one or more heat pipes 25, a portion of its length (hot portion) 570 is exposed to a heat source, and different portions of its length (cold portions) 575 are exposed to cooler feed water 45 flows. Heat transfers from the heat source 580 (hot portion) to the feed water 45 flows (cold portion) to produce a preheated feed water stream to be fed into a reverse osmosis system 540. The heat pipes are installed on a perforated plate 585 that is part of a housing on 115. Heat pipe 25 can be installed in any orientation (vertical, horizontal, or any other angle). The length of the heat pipe can vary. The hot section The length of the heat pipe in 570 can vary. The cold section The length of the heat pipe in 575 can vary. The installation orientation of the heat pipe in the hot section can be the same as or different from that in the cold section. The cold section can be adjacent to the hot section, or the two sections can be separated. Heat can be provided by a single or multiple sources, namely hot fluid or gas, steam, hot water, flue gas, exhaust gas, thermal fluid, geothermal fluid or gas, molten salt, electric heat source, solar energy captured via radiation or photovoltaic. Annular heat pipe for flue gas type water purification or feed water concentration system Flue gas is well known. Flue gas generated by fossil fuel combustion or industrial heating reactions contains a large amount of thermal energy. The temperature of the flue gas can range from 20°C or lower to 300°C or higher. It is usually necessary to reduce the temperature of the flue gas. A typical solution for cooling flue gas is to insert a certain length of metal pipe into the flue gas pipe, where the flue gas transfers thermal energy through the pipe wall to increase the temperature of the fluid flowing through the pipe. In one aspect of the present invention, an annular heat pipe can be used instead of a pipe to recover heat from the flue pipe. The recovered heat can then be applied elsewhere. In some embodiments, where the recovered heat is used to provide thermal energy for a water purification system (as shown in Figure 65), one or more annular heat pipes A part of its length (hot section) of 640 is in the flue gas pipe 610. The annular heat pipe Another part of the length of 640 (cold section) is in the evaporation chamber as described elsewhere in the present invention 20 in contact with the feed water 45. The evaporation chamber 20 The pressure can be set such that boiling occurs at the temperature of the cold section of the annular heat pipe. The evaporation chamber 20 The steam generated in 50 is guided as described elsewhere in the present invention to another one or more stages (Figure 65) composed of the condensation chamber 35, the heat pipe 25 assembly and the evaporation chamber 20. In other aspects, other types of heat pipes are used. In another aspect of the present invention (Figure 66), the steam 20 generated in 50 can be guided to the demister 30 and the condensation chamber 35, or directly guided to the condensation chamber 35 so that the steam condenses to produce purified water 65. In another aspect, the steam from the evaporation chamber 20 (with or without a demister 30) can be directly used in applications such as heating in the chemical industry or other industrial applications that require steam. Annular heat pipes for geothermal energy capture In one aspect of the present invention, the annular heat pipe can be used as a heat transfer device to transfer heat from a geothermal source to a location at a distance (including the earth's surface) so that the recovered heat can be applied to other processes. The efficiency of the annular heat pipe allows for more energy transfer over longer distances than conventional geothermal capture techniques. The annular heat pipe allows for heat transfer over distances in the range of less than 2 m to greater than 20 km with minimal losses. In one embodiment, a portion of the length (the hot portion) of one or more annular heat pipes is in contact with the geothermal source. Another portion of the annular heat pipe length (the cold portion) is in contact with the feed water inside the evaporation chamber as described elsewhere in the present invention. The feed water can be boiler feed water for producing steam for beneficial use, or feed water for a water purification system as described elsewhere in the present invention. In another embodiment, the cold portion of the annular heat pipe can be in a container containing hot oil so that the geothermal heat is transferred into the hot oil for storage or for other processes that require heat energy. Annular heat pipes for low-level long-distance heat capture for water purification or feed water concentration systems In another aspect of the present invention, a system for water purification can use an annular heat pipe to be operated by heat energy from a location at a distance. The efficiency of the annular heat pipe allows for more energy transfer over longer distances than conventional heat energy transfer techniques. The annular heat pipe allows for heat transfer over distances in the range of less than 2 m to greater than 20 km with minimal losses. In one embodiment, a portion of the length (the hot portion) of one or more annular heat pipes is in contact with the heat source. The heat source can be steam, electricity, natural gas furnace, oil furnace, coal furnace, chemical substances, chemical reactions, solar energy, nuclear energy, geothermal energy, molten salt, heat transfer fluid, biomass, compost, fermentation, microwave, flue gas, solid waste, or other waste heat from industrial or other processes. The hot portion can be inside a first chamber, underground, or inside a container open to the atmosphere. Another portion of the annular heat pipe length (the cold portion) is in contact with the feed water inside the first evaporation chamber of the water purification system as described elsewhere in the present invention. Heat pipes in a once-through steam generator In one aspect of the present invention, heat pipes are used as heat transfer devices in a once-through steam generator. In one embodiment, a portion of the length of one or more heat pipes (the hot portion) is in contact with a heat source. The heat source can be steam, electricity, natural gas furnace, oil furnace, coal furnace, chemical substances, chemical reactions, solar energy, nuclear energy, geothermal energy, molten salt, heat transfer fluid, biomass, compost, fermentation, microwave, flue gas, solid waste, alcohol furnace, and waste heat from industrial or other processes. The hot portion can be inside a first chamber, underground, or inside a container open to the atmosphere. Another portion of the heat pipe length (the cold portion) is in contact with water inside an evaporation chamber. This portion can be in any orientation (vertical, horizontal, or at an angle). The orientation of the heat pipes in the evaporation chamber does not need to be the same as the orientation of the hot zone. If multiple heat pipes are used, they can have different orientations. The cold portion can be submerged in a pool of water, or water can be sprayed onto the cold portion, or a water film can flow over the surface of the cold portion. Water from the spray or falling film can be recovered and reused for spraying or to form a falling film. Heat is transferred from the hot portion to the cold portion. In the cold portion, the heat is transferred to the water, causing the water to evaporate and steam to form. Water can be fed continuously or at intervals to maintain the water content in the evaporation chamber within a specified value. Fluids other than water can be used in the evaporation chamber. In addition to the hot and cold portions, the heat pipe can have one or more intermediate portions, such as a portion that operates through the wall of the evaporation chamber or an insulated portion that connects hot and cold zones that do not directly contact each other, so that a heat source far from the evaporation chamber can be used. Heat pipes in a single-stage boiler for driving a distillation column and heat pipes in a reboiler In one aspect of the present invention, heat pipes are used as heat transfer devices in a reboiler to supply heat to a distillation column. In one embodiment, a portion of the length of one or more heat pipes (the hot portion) is in contact with a heat source. The heat source can be steam, electricity, natural gas furnace, oil furnace, coal furnace, chemical substances, chemical reactions, solar energy, nuclear energy, geothermal energy, molten salt, heat transfer fluid, biomass, compost, fermentation, microwave, flue gas, solid waste, alcohol furnace, and waste heat from industrial or other processes. The hot portion can be inside a first chamber, underground, or inside a container open to the atmosphere. Another portion of the heat pipe length (the cold portion) is in contact with the fluid at the bottom of the distillation column inside an evaporation chamber. In one aspect, the hot portion is inside the bottom of the distillation column. Due to the high efficiency of heat transfer associated with the heat pipe, compared to the case of a reboiler using a conventional heat exchanger, a small tower size is unlikely to be a limiting factor. In another aspect, the hot portion is in a chamber adjacent to the bottom of the distillation column, where at least two pipes connect the two containers, one pipe transfers the distillation bottoms to the evaporation chamber, and the other pipe transfers the vapor or vapor-liquid mixture from the evaporation chamber to the distillation column. The cold portion can be submerged in a liquid pool of the distillation bottoms, or liquid can be sprayed onto the cold portion, or a liquid film can flow over the surface of the cold portion. Liquid from the spray or falling film can be recovered and reused for spraying or to form a falling film. Heat is transferred from the hot portion of the heat pipe to the cold portion.In the cold part, heat is transferred to the bottoms liquid of the distillation, resulting in evaporation. The liquid may be fed continuously or at intervals to maintain the liquid content in the evaporation chamber within a specified value. In addition to the hot and cold parts, the heat pipe may have one or more intermediate parts, such as parts operating through the wall of the evaporation chamber or insulating parts connecting hot and cold zones that do not directly contact each other, so that heat sources remote from the evaporation chamber can be used. Heat pipes for ammonia removal systems In another aspect of the present invention, a system for water purification can operate without passing feed water through an evaporation chamber. The system can include pretreatment, a preheater, and a deaerator. The function of the deaerator can be to separate volatile species from the feed water. In one aspect, the volatile species can be ammonia, volatile organic compounds, or a mixture of such species. The pretreatment can include the same steps as described in other embodiments of the present invention. The preheater can include a heat pipe, a hot plate, a heat exchanger, or other heat transfer devices. For example, the preheater can include a container having heat pipes, where a portion of each heat pipe can be in contact with the feed water, and the remaining portion of the heat pipe is in contact with a heat source outside the container, the heat source including (but not limited to) steam, electricity, natural gas furnace, oil furnace, coal furnace, chemical substances, chemical reactions, solar energy, nuclear energy, geothermal energy, molten salt, heat transfer fluid, biomass, compost, fermentation, microwave, flue gas, solid waste, alcohol furnace, other waste heat from industrial or other processes. The deaerator can include one or more containers, such as the containers described in other embodiments of this application, including packed towers, containers with plates, empty towers with nozzles, or other gas-liquid contactors. An air stream is used to separate the species removed from the water and carry them away from the deaerator. The gas can be steam, air, inert gas, CO2, methane, natural gas, flue gas, and mixtures of such gases. The gas can be injected at one or more locations in the deaeration chamber. Heat pipes for fruit juices and other concentrators In some embodiments of the present invention, a system for concentrating a liquid feed can include pretreatment, a deaerator, a preheater, one or more evaporation chambers and demisters, one or more product condensation chambers, inlets and outlets for liquid and gas flows, a control system, and one or more heat recovery units. These components can be used in the same configuration as described in the system for water purification. Other embodiments of the present invention do not necessarily include all of the listed components, and the omitted components will be specified by the nature of the purification being carried out, including the nature of the feed water, the intended use of the product and the concentrate, and the like. The liquid feed is passed through one or more evaporation chambers to separate a portion (or all) of one or more species in gaseous form; thus, the concentration of other species in the feed increases, and a fluid product can be obtained from the system by gravity, by pumping action, by hydrostatic pressure, or by any other suitable process. For example, fruit juice can be the liquid feed and fruit juice concentrate is the product. As another example, milk can be the feed and concentrated milk is the product. Heat pipes in crystallizers A crystallizer is a unit where solute mass transfer from a liquid solution to a solid crystalline phase occurs. In some applications, the crystallizer separates the solute from the brine / concentrate by evaporating water, so that the resulting wet solid can be easily processed (with or without further drying) in zero liquid discharge (ZLD) applications. A feed water concentrator and an evaporator are units that concentrate the feed water by evaporating a portion of the solute. The crystallizer, the feed water concentrator, and the evaporator can be operated by several energy sources, including steam recompression, steam from other units, electric heaters, or conventional heat exchangers.In one embodiment shown in FIG. 67, the heat required for evaporating the solvent and inducing crystallization is provided by a heat pipe. A portion (the hot portion) of the length of the heat pipe is in contact with a heat source 25. The heat source 580 can be steam, electricity, a natural gas furnace, an oil furnace, a coal furnace, a chemical substance, a chemical reaction, solar energy, nuclear energy, geothermal energy, molten salt, a heat transfer fluid, biomass, compost, fermentation, microwaves, flue gas, solid waste, an alcohol stove, and waste heat from an industrial or other process. The hot portion can be inside a first chamber, underground, or inside a container open to the atmosphere. Another portion (the cold portion) of the length of the heat pipe is inside the crystallizer 590. The cold portion can be placed in a recirculation loop in the crystallizer or the main crystallization chamber or both. The crystallizer feed 625 is fed into the crystallizer, where it is further concentrated by evaporation. The steam 245 generated is sent to a condenser 595 that produces purified water 65. The slurry leaving the crystallizer is fed into a filter 700, where more water is removed, thereby forming a filter cake 705 that is more easily disposable. In other embodiments, the slurry can be centrifuged, dried in a pond, reused for other applications, or processed in any other conventional manner. In other embodiments, the heat recovered in the condenser 595 can be used to preheat the crystallizer feed 625 by means of a heat pipe, a heat exchanger, or other heat transfer device. In other embodiments, the solution or suspension in the crystallizer can be recycled via a heat exchanger or a heat pipe heat exchanger. In other embodiments, baffles and flow deflectors can be used to control the crystal growth rate and crystal size distribution. The crystallizer can also be used as part of a water purification system. In this case, the concentrated brine / solution fed into the crystallizer is the final concentrate from the water purification system as described above. The output stream of the crystallizer is the steam to be converted into purified water and solids. The crystallizer can have a heat pipe, a heat exchanger, or vapor recompression. In another embodiment shown in FIG. 68, the heat pipe 25 is used in the condenser 595 to recover the heat of vaporization of the steam 245 released from the crystallizer 590 to preheat the final concentrate 55 from the water purification system before it enters the crystallizer 590 as the crystallizer feed 625. In addition, the condensed water ​ 65 can be used as a product. In the illustrated embodiment, some of the solution or suspension leaving the crystallizer 590 is recycled via a recycle loop 620 for input into the crystallizer 590. Heat pipes may be present in the main body of the crystallizer 590, the heat pipe heat exchanger in the recycle loop 620, 615 and the condenser 595. It may also be present in only some of these locations. The heat source 580 can be any of those listed in the description of FIG. 69. FIG. 69 shows the heat pipe heat exchanger 615 in more detail. The heat pipe heat exchanger 615 has two parts separated by a perforated plate 115 and heat pipes 25 operating through the perforated plate 115 such that it fills the orifices in the perforated plate, seals the voids and there is no fluid communication between the two parts. In one part of the heat pipe heat exchanger 615, the heat source 580 contacts the heat pipe 25. The heat source 580 can be any of those listed in the description of FIG. 69. The heat pipe 25 transfers heat to the fluid circulating in the other part of the heat pipe heat exchanger 615, and the fluid carries some of the solution or suspension recycled via the recycle loop 620 leaving the crystallizer 590. This part of the heat pipe heat exchanger 615 has a sleeve 460 surrounding the heat pipe 25. The sleeve 460 reduces the cross-sectional area of the fluid flow, resulting in a higher linear velocity of the fluid, a thinner boundary layer in the fluid, a higher Reynolds number in the fluid, a better heat transfer coefficient from the heat pipe 25 to the fluid and a lower scale formation rate on the surface of the heat pipe 25. The outer surface of the heat pipe 25 and the sleeve The typical distance between the inner surfaces of 460 can be less than 1 mm. In other embodiments, it can be less than 1 cm. In other embodiments, it can be less than 5 cm. In another embodiment shown in FIG. 70, the final concentrate from the water purification system 55 is fed into the flash chamber 635, where it undergoes flashing. The flash chamber The steam generated in 635 245 is separated from the final concentrate 55. In the condenser 595, heat pipes 25 are used to recover the heat of vaporization of the steam released from the crystallizer 590 and the flash chamber 635, and this heat is used to preheat the feed water 245. The preheated feed water 95 is delivered to the water purification system. The condensate 65 can be used as a product. The final concentrate 55 is further concentrated in the flash chamber 635 and leaves as crystallizer feed 625, which can be a solution (supersaturated in some cases) or a suspension. In the illustrated embodiment, some of the solution or suspension leaving the crystallizer 590 is recycled via the recycle loop 620 for input into the crystallizer 590. Heat pipes can be present in the main body of the crystallizer 590, in the heat pipe heat exchanger 620 in the recycle loop 615 and in the condenser 595. It can also be present in only some of these locations. The heat source 580 can be FIG Any of those listed in the description of 69. Feed water in the membrane distillation heating membrane distillation system can improve the overall efficiency of the distillation process. Additionally, controlling the temperature along the membrane can also improve efficiency by keeping the feed water at an optimal temperature throughout the system. Figure 71 (source: "Advances in Membrane Distillation for Water Desalination and Purification Applications", Camacho et al.) shows various different types of membrane distillation configurations that can be used in embodiments of the present invention. Configuration (a) is direct contact membrane distillation, where 590 is the membrane, 715 are the membrane pores, 45 is the feed water and 654 is the purified water. Configuration (b) is Gore-Tex membrane distillation, where 720 is the hot feed water, 45 is the cold feed water, 725 is the cooling plate and 65 is the purified water. Configuration (c) is vacuum membrane distillation, where 45 is the feed water, 730 is the vacuum environment, and 65 is the purified water. Configuration (d) is sweep gas membrane distillation, where 45 is the feed water, 735 is the sweep gas and 740 is the purified water vapor. The standard membrane distillation configuration assumes that the feed water is hotter than the purified water. A larger temperature difference results in an efficiency improvement. Figure 72 shows two types of membrane configurations, hollow fiber (a) and flat sheet (b), that can be used in some embodiments of the present invention. The membrane in the hollow fiber configuration is the cylindrical wall 745. The flat sheet configuration has two components, the active layer 750 and the support layer 755. For compactness, the flat sheet can also be rolled into a roll. Two basic ways of using heat pipes under membrane distillation can be as follows: i) Replace the conventional heat exchanger with a heat pipe heat exchanger to heat the feed water. ii) Use one or more heat pipes in the rolled membrane to achieve a better distribution of the heated liquid. Figure 73 shows a typical membrane roll with a feed water pipe 760 and purified water 65 flowing out of the roll 765. Figure 74 shows this type of configuration, where one or more heat pipes placed in the membrane roll 765 to maintain a relatively constant temperature along the axis of the roll. Figure 74 shows a similar configuration, but in which the heat pipe 25 is inserted into the feed water pipe 760. Heat 580 is applied to the heat pipe 25 so that the heat pipe can raise the temperature of the feed water to improve the membrane roll 765 efficiency. A hot plate can also be used in a membrane distillation system to maintain a relatively constant temperature on the thin film membrane or preheat the feed water. Since heat pipes and hot plates can also be used to remove heat, one or more heat pipes or one or more hot plates can be constructed as cooling plates 725 or used to cool the cold plate (see Figure 71). The configurations described above can be used in single membrane systems or multi-effect membrane distillation systems. Heat pipes, pulsating heat pipes, hot plates, radiators, thermosyphons, and heat rods are all candidates for these embodiments. The heat used for heat pipes and hot plates can come from a variety of sources, including steam, electricity, natural gas furnaces, oil furnaces, coal furnaces, chemicals, chemical reactions, solar energy, nuclear energy, geothermal energy, molten salts, heat transfer fluids, biomass, compost, fermentation, microwaves, flue gas, solid waste, or other waste heat from industrial or other processes. Cooling can come from pressurized air, water evaporation, refrigeration, and other sources. Heat pipes used in electrodialysis systems The electrodialysis efficiency improves as the feed water temperature increases. High-temperature electrodialysis is a well-studied field. Electrodialysis can be carried out by a single set of units or multiple unit groups. Electrodialysis can also be carried out in a process in which a gas is injected into the unit to help prevent scale buildup on the membrane (see, for example, U.S. Patent 4,311,575). In some embodiments of the present invention, heat pipes and hot plates can be used in an electrodialysis system in various ways. Figure 75 shows an electrodialysis, which includes an anode 770, a cathode 775, purified water 65, final concentrate 55, anode electrolyte 795, cathode electrolyte 800, feed water 45, concentrate solution 790, anion exchange membrane 785 and cation exchange membrane 780. In this embodiment, a heat pipe (or hot plate) heat exchanger 615 replaces a standard heat exchanger to heat the solution 45 and 790, and then injecting it into the unit. Another embodiment also shown in FIG. 75 includes a hot plate (or heat pipe) within the unit to maintain a relatively constant temperature throughout the unit to improve overall efficiency. These embodiments can be used together or individually. FIG. 76 shows another embodiment of an electrodialysis system where a gas 805 is injected into the unit to reduce scale formation. In this embodiment, a heat pipe (or hot plate) heat exchanger 615 is used to heat the gas 805, and then injecting it into the unit. A hot plate (or heat pipe) 25 is also shown inside the unit to maintain a relatively constant temperature throughout the unit. Additionally, in one embodiment, the heat pipe heat exchanger 615 and the hot plate 25 can be used together, or in other embodiments either one can be used individually. Heat pipes, hot plates, radiators, or heat rods are all candidates for use in these embodiments. Hot plates in dew evaporation The process of dew evaporation uses air as a carrier gas, which transfers water vapor from the rising evaporation channels to adjacent descending dew formation channels. The heat flowing through the barrier allows the heat released by condensation on the dew formation side to fully meet the evaporation energy requirements. A small pressure difference is maintained to keep the condensed colder air on the cold side. The present invention uses a hot plate in a dew evaporation system. A detailed description of the dew evaporation system can be found, for example, in U.S. Patent US 8444829 B2, "Systems, Processes and Methodologies for Producing Clean Water", which is incorporated herein by reference. FIG. 77 shows a possible embodiment of the present invention. The dew evaporation housing 510 is divided into an evaporation section 820 and a condensation section 825 by a hot plate . The hot plate is composed of one or a plurality of heat transfer elements of a sealed metal structure. Depending on the corrosion resistance requirements, the metal housing can be inoculated or not. Each element is sealed and contains a partial vacuum, one or a plurality of core structures, and a working fluid. The hot plate can be installed vertically or at an alternative angle. Hot air 835 or a mixture of air and other gases or gas mixtures enters the housing 815. The inlet air stream can be heated by: steam, electricity, natural gas furnace, oil furnace, coal furnace, alcohol furnace, chemical substances, chemical reactions, solar energy, nuclear energy, geothermal energy, molten salt, heat transfer fluid, biomass, compost, fermentation, microwave, flue gas, solid waste, or waste heat from industrial or other processes. When the hot air stream rises, it contacts the hot plate Water supply on the evaporation surface of 510 45 Falling film. The water supply can also be heated by one or more of the same sources listed above. The water supply temperature can vary between 20 °C and 99 °C. Some portions of the falling film water are evaporated by the hot air stream, and the resulting humid air stream 840 is carried across the hot plate / heat transfer wall To the top of 510. When the humid air stream flows downward on the condensation side of the hot plate 825, some portions of the water vapor will condense on the condensation surface of the hot plate. The condensation enthalpy or heat will be transferred through the hot plate to the evaporation side of the hot plate Of 510 820. The energy transfer mechanism in the hot plate is similar to the energy transfer mechanism in the heat pipe. The energy can then be used to evaporate the falling film of the water supply. The cooler air or gas mixture 845 can be reheated and returned to the evaporation side of the housing, transferred to an adjacent housing, or released to the surrounding environment. The concentrated stream 850 and the purified water 65 are collected from the respective sides of their mounting plates. Heat pipes in dew evaporation Some embodiments of the present invention use heat pipes installed in a mounting plate that provides a heat transfer wall with an evaporation side and a dew formation side in a dew evaporation system. A detailed description of the dew evaporation system can be found, for example, in U.S. Patent US 8444829 B2, "Systems, Processes and Methodologies for Producing Clean Water", which is incorporated herein by reference. FIG. 78 shows a possible embodiment. The dew evaporation housing 830 is divided into an evaporation part 820 and a condensation part 825 by the mounting plate 825. The mounting plate can be made of metal, non-metal, or a combination of materials. The heat pipe 25 is installed in the mounting plate at an angle that can range from horizontal to vertical. The lengths of the heat pipes can vary. The lengths of the heat pipes in the evaporation part can vary. The lengths of the heat pipes in the condensation part can vary. The diameters of the heat pipes can be equal or the diameters can vary. The mounting plate is formed to guide the falling water film to cover the surface of the heat pipes in the evaporation part. The hot air 835 or a mixture of air and other gases or gas mixtures enters the housing In 815. The inlet air stream can be heated by: steam, electricity, natural gas furnace, oil furnace, coal furnace, alcohol furnace, chemical substances, chemical reactions, solar energy, nuclear energy, geothermal energy, molten salt, heat transfer fluid, biomass, compost, fermentation, microwave, flue gas, solid waste or waste heat from industrial or other processes. When the hot air stream rises, it contacts the water feed falling film on the heat pipe surface on the evaporation side of the mounting plate 830. The water feed 45 can also be heated by one or more of the same sources listed above. The water feed temperature can vary between 20°C and 99°C. Some portions of the falling film water will be evaporated by the rising hot air stream, and the resulting moist air stream 840 will be carried over the mounting plate 830 at the top. When the moist air stream 840 flows downward on the condensation side of the mounting plate 825, some portions of the water vapor will condense on the condensation surface of the mounting plate, and some portions will condense on the condensation side of the heat pipe. The condensation enthalpy or heat will be mainly transferred through the heat pipe to the evaporation side of the heat pipe 25 820. The energy from the condensation can then be used to evaporate the water feed falling film. The cooler air or mixed gas 845 can be reheated and returned to the evaporation side of the housing, transferred to an adjacent housing, or released to the surrounding environment. The concentrated stream 850 and the purified water 65 are collected from the respective sides of their mounting plates. The invention described illustratively herein can be practiced suitably without any one or more elements, one or more limitations not specifically disclosed herein. The terms and expressions used are used as terms of description and are not restrictive, and in using such terms and expressions, it is not intended to exclude equivalents or portions thereof of the features shown and described. It should be recognized that various modifications are possible within the scope of the invention. Accordingly, it should be understood that although the invention has been specifically disclosed by way of preferred embodiments and features selected as appropriate, those skilled in the art may adopt modifications and variations of the concepts disclosed herein, and such modifications and variations are considered to be within the scope of the invention as defined by the invention. Those skilled in the art recognize that the aspects and embodiments of the invention described herein can be practiced separately from each other or in combination with each other. Accordingly, combinations of individual embodiments are within the scope of the invention as disclosed herein. All patents and publications are incorporated herein by reference to the extent as if each individual publication was specifically and individually incorporated by reference. 10: Preheater 15: Degasser 20: Evaporation chamber 25: Heat pipe or thermosyphon 30: General demister 35: Condenser 40: Energy input container 45: Feed water 50: Steam from evaporation chamber 55: Final concentrate 60: Energy input to system 65: Purified water 70: Intermediate concentrate 75: Degassed feed water 80: Pretreated feed water 85: Solids 90: Stage 95: Preheated feed water 100: Airflow into degasser 105: Degasser waste 110: Heat transfer device 115: Perforated plate 120: In-situ cleaning solution 125: Pump 130: Valve 135: Zigzag path 140: Steam generator 145: Condensate from energy input container 150: Steam from steam generator 155: Feed water inlet 160: Mounting hole for heat pipe 165: Downcomer 170: Outer shell 175: Oil or gas burner 180: Steam ejector 185: Preheated feed water outlet 190: Steam capture chamber (Figure 9) 195: Large degasser particles 200: Medium degasser particles 205: Small degasser particles 210: Degasser nozzle 215: Discharge pipe for intermediate concentrate 220: Demister waste 225: Pad demister 230: Groove 235: Demister droplets 240: Baffle 245: Contaminated steam 250: Top evaporation chamber 255: Vortex demister 260: Vortex demister inlet 265: Vortex region 270: Demisted and cleaned steam outlet 275: Demister waste outlet 280: Heat flow 285: Condenser inlet 290: Purified water outlet 295: Steam spray 300: Scale 305: Thin layer (regulation) 310: Device for scale removal (also known as robotic cleaner) 315: Electrode 320: Electrical insulator 325: Purified ice 330: Intermediate concentrate outlet 335: Flexible seal 340: Intermediate concentrate inlet 345: Intermediate concentrate sprayer 350: Heat pipe seal tube 355: Heat pipe working fluid 360: Capillary wick 365: Heat pipe heat source 370: Vibration energy 375: Hydrophobic coating 380: Thin foil 385: Metal screen 390: Resistance heater 395: Insulating sleeve 400: Power supply 405: Waste heat 410: Heat fluid 415: Steam ejector 420: Motive steam 425: Steam from ejector 430: Mechanical vapor compressor 435: Condensate entering steam generator 440: Inclination angle 445: Retainer 450: Threaded insert 455: Flexible insulating sleeve 460: Sleeve 465: Coating 470: Metal sleeve 475: Connecting material 480: Deformation 485: Flexible material 490: Fixed plate 495: Mounting plate 500: Fastening piece 505: Separation plate 510: Heat plate 515: Heat exchanger520: NF or UF system 525: Concentrate waste stream 530: Disposal concentrate discharge port 535: Feed water for NF / UF treatment 540: Feed water preheated by NF / UF 545: Water purification concentrate system 550: Temperature bypass control valve 555: Temperature probe 560: Cleaning particles 565: Porous cylinder 570: Length exposed to heat 575: Length exposed to feed water 580: Universal heat source 585: Heating housing 590: Crystallizer 595: Universal condenser 600: Flue gas inlet 605: Flue gas outlet 610: Flue gas pipe 615: Heat pipe heat exchanger 620: Recirculation loop 625: Heat input section outlet 630: Flash chamber 635: Annular heat pipe 700: Filter 705: Solid 710: Membrane 715: Pore 720: MD preheated feed 725: Cooling plate 730: Vacuum 735: Sweep gas 740: Purified water vapor 745: Membrane wall 750: Active layer 755: Support layer 760: Feed water pipe 765: Membrane roll 770: Anode 775: Cathode 780: Cation exchange membrane K 785: Anion exchange membrane A 790: Electrodialysis concentrate 795: Anolyte 800: Catholyte 805: Injection gas ED 810: Injection gas ED heater 815: Dew evaporation housing 820: Evaporation part of dew evaporation 825: Condensation part of dew evaporation 830: Dew evaporation mounting plate 835: Hot air 840: Humid air 845: Cooling air 850: Dew evaporation concentrate 855: Filtered and desalinated water 860: In-line booster pump 865: Mixer-settler vessel 870: Metering pump 875: Caustic soda storage tank 880: Variable valve 885: Mg(OH)2 slurry 890: First filter cake 895: Static mixer 900: CO2 storage tank 905: Second filter cake 910: Detergent water In some cases, embodiments of the present invention are disclosed herein in an illustrative form or with reference to one or more figures. However, any such disclosure of a particular embodiment is merely illustrative and does not indicate the full scope of the present invention. FIG. 1 is a schematic diagram of a typical embodiment of a purification or feed water concentration system. FIG. 2 shows a general configuration of a purification system. FIG. 3 is a schematic diagram of a water purification or feed water concentration system having two purified water production stages. FIG. 4 is a schematic diagram of a stage of a water purification or feed water concentration system. FIG. 5 is a schematic diagram of a water purification or feed water concentration system having five purified water production stages. FIG. 6 is a schematic diagram of a water purification or feed water concentration system having two purified water production stages and purified water feedback. FIG. 7 is a diagram of a perforated plate. FIG. 8 is a diagram of a stage of a water purification or feed water concentration system having a downcomer. FIG. 9 shows a front view of a purification or feed water concentration system having stacked stages. FIG. 10 shows a front view of a purification or feed water concentration system operating in a countercurrent mode and having stacked stages. FIG. 11 is a schematic flowchart of a pretreatment process. FIG. 12 is a schematic diagram of a feed water preheating chamber in a purification or feed water concentration system. FIG. 13 is a schematic diagram of a feed water deaerator in a purification or feed water concentration system. FIG. 14 shows a cross-sectional view of a feed water deaerator in a purification or feed water concentration system. FIG. 15 is a schematic diagram of an evaporation chamber having a deaerator in a purification or feed water concentration system. FIG. 16 is a schematic diagram of an evaporation chamber without a deaerator in a purification or feed water concentration system. FIG. 17 shows a demister configuration having a protective baffle, grooves, and a demisting pad. FIG. 18 is a schematic diagram of an evaporation chamber. FIG. 19 is a schematic diagram of a vortex demister. FIG. 20 is a schematic diagram of a condensation chamber having a helical blade. FIG. 21 is a schematic top view of a condenser chamber having a helical blade. FIG. 22 is a schematic diagram of a conventional heat pipe. FIG. 23 is a schematic diagram of a high-efficiency heat pipe. FIG. 24 is a diagram of a control circuit in a purification or feed water concentration system. FIG. 25 shows several energy input configurations. FIG. 26 shows a schematic diagram of a purification or feed water concentration system operating under vacuum and using thermal vapor compression. FIG. 27 shows a schematic diagram of a purification or concentration system operating under vacuum and using mechanical vapor compression. FIG. 28 shows a schematic diagram of a purification or concentration system having a single water production evaporation chamber. FIG. 29 shows a schematic diagram of a purification or concentration system using heat pipes and mechanical vapor compression. FIG. 30 shows a schematic diagram of the operation of a purification or concentration system in a horizontal configuration. FIG. 31 is a schematic diagram of an evaporation chamber for spraying feed water or intermediate concentrate onto the surface of a heat pipe. FIG. 32 shows a schematic diagram of a purification or concentration system using annular heat pipes in and between stages. FIG. 33 is a schematic diagram of a stage of a water purification or feed water concentration system having inclined heat pipes. FIG. 34 is a schematic diagram of a stage of a water purification or feed water concentration system having heat pipes of different heights. FIG. 35 is a schematic diagram of a stage of a water purification or feed water concentration system having alternative steam injection. FIG. 36 shows a schematic diagram of a heat pipe installed on a perforated plate.Figure 37 shows a schematic diagram of a heat pipe installed on a perforated plate with a machined groove. Figure 38 shows a schematic diagram of a heat pipe held by an insert penetrating the perforated plate. Figure 39 shows a schematic diagram of a heat pipe held by an electrical insulation sleeve installed on the perforated plate. Figure 40 shows a schematic diagram of a heat pipe held by another electrical insulation sleeve installed on the perforated plate. Figure 41 shows a schematic diagram of a heat pipe held by another sleeve installed on the perforated plate. Figure 42 shows a schematic diagram of a heat pipe installed on a coated perforated plate. Figure 43 shows a schematic diagram of a heat pipe installed vertically on a perforated plate. Figure 44 shows a schematic diagram of a heat pipe installed on a perforated plate at an angle. Figure 45 shows a schematic diagram of a heat pipe connected to a sleeve installed on a perforated plate. Figure 46 shows a schematic diagram of a heat pipe held by a conical sleeve installed on the perforated plate. Figure 47 shows a schematic diagram of a heat pipe held by local deformation of the perforated plate. Figure 48 shows a configuration of multiple heat pipes installed on a perforated plate. Figure 49 shows a configuration of multiple heat pipes installed on a perforated plate. Figure 50 is a schematic diagram of a water purification or feed water concentration system using a hot plate. Figure 51 is a schematic diagram of a stage of a water purification or feed water concentration system using a corrugated hot plate. Figure 52 shows a system for reducing water hardness using an ultrafiltration or nanofiltration process. Figure 53 is a diagram illustrating the self-cleaning feature of a heat pipe. Figure 54 is a diagram showing the pipeline and valve configuration when a stage of a purification or concentration system stops working for cleaning or maintenance work. Figure 55 is a diagram showing the pipeline and valve configuration when a stage of a purification or concentration system stops working for cleaning or maintenance work. Figure 56 is a schematic diagram of an adjustment and in-situ cleaning process for cleaning scale deposited on the surface of a heat transfer device. Figure 57 is a diagram showing the pipeline and valve configuration when a degasser stops working for cleaning or maintenance work. Figure 58 is a schematic diagram of a thermal shock process for cleaning scale deposited on the surface of a heat transfer device. Figure 59 is a schematic diagram of a robot for cleaning scale deposited on the surface of a heat transfer device. Figure 60 is a schematic diagram of a configuration for applying an electric bias voltage to a heat pipe to reduce the rate of scale formation on the surface of a heat transfer device. Figure 61 is a schematic diagram of a configuration for applying an electric bias voltage to a heat pipe to reduce the rate of scale formation on the surface of a heat transfer device. Figure 62 is a schematic diagram of a multi-stage flash evaporator and multi-effect distillation system with heat pipes. Figure 63 is a schematic diagram of a refrigeration-desalination process using heat pipes. Figure 64 is a schematic diagram of a system using a heat pipe as a heater for nanofiltration, ultrafiltration, or reverse osmosis. Figure 65 is a schematic diagram of a system using a ring-shaped heat pipe for a pipeline gas type water purification or solution concentration system. Figure 66 is another schematic diagram of a system using a ring-shaped heat pipe for a pipeline gas type water purification or solution concentration system. Figure 67 is a schematic diagram of a crystallizer with heat pipes. Figure 68 is a schematic diagram of a crystallizer with heat pipes, liquid recirculation by a heat pipe heat exchanger, and steam energy recovery for preheating the crystallizer feed.Figure 69 shows a schematic diagram of a heat pipe heat exchanger. Figure 70 is a schematic diagram of a crystallizer having heat pipes, liquid recirculation by the heat pipe heat exchanger, steam energy recovery for preheating feed water for a purification or concentration system, and a flash chamber for evaporating some water from the final concentrate of the purification or concentration system. Figure 71 is a schematic diagram of a membrane distillation configuration. Figure 72 shows a schematic diagram of two types of membranes. Figure 73 is a schematic diagram of a wound membrane without heat pipes. Figure 74 is a schematic diagram of a wound membrane with heat pipes. Figure 75 is a schematic diagram of a system using heat pipes in electrodialysis. Figure 76 is a schematic diagram of a system using heat pipes in electrodialysis under an injected gas. Figure 77 is a schematic diagram of a system using heat pipes in dew evaporation. Figure 78 is another schematic diagram of a system using heat pipes in dew evaporation. 10: Preheater 15: Degasser 20: Evaporation chamber 25: Heat pipe or thermosyphon 30: Universal demister 35: Condenser 40: Energy input container 45: Feed water 50: Steam from the evaporation chamber 55: Final concentrate 60: Energy input to the system 65: Purified water 70: Intermediate concentrate 75: Degassed feed water

Claims

1. A method for removing scale, comprising the steps of: a) providing a water treatment system having elements that are prone to scale formation during operation of the water treatment system; b) depositing a thin layer of carbonate on at least some of the elements that are prone to scale formation; c) operating the water treatment system by allowing feedwater to flow into the water treatment system and heating the feedwater, thereby causing scale to form on the thin layer of carbonate; and d) removing the thin layer of carbonate, and thus removing the scale, during operation of the water treatment system by using one or more acids.

2. The method of claim 1, wherein the carbonate thin layer is selected from the group consisting of calcium carbonate, magnesium carbonate, strontium carbonate and barium carbonate.

3. The method of claim 1, wherein the carbonate layer is deposited from an aqueous carbonate solution onto at least some of the components prone to scale formation by one or more of evaporation and chemical treatment.

4. The method of claim 3, wherein the carbonate layer is deposited by chemical treatment, and wherein the carbonate layer is calcium carbonate, and the chemical treatment comprises one or more selected from the group consisting of: adding sufficient calcium-containing chemical species and carbonate-containing chemical species to an aqueous solution to increase the molar concentration of calcium and carbonate ions above their solubility product; adding sufficient carbonate-containing chemical species to the aqueous solution to increase the molar concentration of calcium and carbonate ions above their solubility product; adding a bicarbonate-containing chemical species and a base to the aqueous solution to increase the pH of the aqueous solution to a range where the carbonate-bicarbonate equilibrium begins to shift towards carbonate; adding a base to the aqueous solution to increase the pH of the aqueous solution; and adding carbon dioxide gas, which is absorbed in the aqueous solution.

5. The method of claim 1, wherein the carbonate layer has a thickness of less than 1 mm.

6. The method of claim 1, wherein the carbonate thin layer has a thickness of less than 1 micrometer.

7. The method of claim 1, wherein the one or more acids have a pH of less than 6.

8. The method of claim 1, wherein the one or more acids have a pH of less than 3.

9. The method of claim 1, wherein the one or more acids are in an aqueous solution.

10. The method of claim 1, wherein the one or more acids comprise one or more selected from the group consisting of citric acid, acetic acid, hydrochloric acid, nitric acid, formic acid and hydrobromic acid.

11. The method of claim 1, further comprising step c' after step c and before step d, wherein step c' comprises mechanically reducing the scale by using one or more of thermal shock and direct mechanical energy, wherein: Thermal shock includes the addition of a liquid mixture that is colder than the scale-forming components, causing the scale-forming components and the scale to shrink by a different fraction of their original volume and resulting in scale cracking; and direct mechanical energy includes vibration, tapping and / or sound.

12. The method of claim 11, wherein the liquid mixture comprises a solvent combined with one or more of the group selected from dry ice and liquid nitrogen.

13. The method of claim 11, wherein the liquid mixture comprises ice and one or more salts in a solvent.

14. The method of claim 11, wherein the liquid mixture has a temperature of less than 10°C.

15. The method of claim 11, wherein the liquid mixture has a temperature of less than -40°C.

16. The method of claim 1, further comprising step c'' after step c and before step d, wherein step c'' comprises partially or completely discharging the water supply from the water treatment system.

17. The method of claim 16 further includes step c''' after step c'' and before step d, wherein step c''' includes completely discharging the water supply from the water treatment system, and step c''' includes drying the elements that are prone to scale formation.

18. A method for removing scale, comprising the steps of: a) providing a water treatment system having elements that are prone to scale formation during operation of the water treatment system; b) depositing a thin layer of CaCO3 from an aqueous solution onto at least some of the scale-prone elements by chemical treatment, the chemical treatment comprising adding an alkali to the aqueous solution to increase the pH of the aqueous solution and adding carbon dioxide gas, which is absorbed in the aqueous solution; c) operating the water treatment system by allowing feedwater to flow into the water treatment system and heating the feedwater, thereby causing scale to form on the thin layer of CaCO3; and d) removing the thin layer of CaCO3 by using one or more acids, thereby removing the scale.

19. The method of claim 18, wherein the use of the one or more acids occurs during the operation of the water treatment system.

20. A water concentration system configured to use the method of any one of claims 1 to 19, the water concentration system including a pump, valves, sensors and a control system to guide fluid flow so that one or more parts of the water concentration system are deactivated for cleaning while other parts remain operational.

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