Hybrid saltwater desalination device using intermittent ionization and ion separation using a rotating magnetic field

Abstract

Nowadays, the issue of drinking water supply has become one of the vital issues in the world. With the advancement of technology, various techniques have been proposed today to supply the required drinking water. Among them is the purification of salt water and its conversion into fresh water. There are various methods and devices for desalination, the most widely used of which are the purification of salt water by reverse osmosis and electrodialysis. These two methods are complex and have high maintenance costs due to their manufacturing technology, so other methods can be proposed, taking into account maximum efficiency, reducing manufacturing and maintenance costs, and energy consumption. The proposed claim is a method that attempts to provide a device capable of purifying water by reducing complexity, production and maintenance costs. This device has the ability to separate salt ions in a salt water solution by using alternating electric fields and a rotating magnetic medium.

Description

Description of the invention Title of the invention Hybrid device for desalination of salt water using intermittent ionization and ion separation using a rotating magnetic field (Hybrid desalination device for saline water using alternating ionization and ionic separation through a rotating magnetic field.) Technical background of the relevant invention The technical field of this invention is in the field of desalination of brackish water using alternating electric fields and rotating magnetic fields. Technical problem and stating the objectives of the invention Existing technical problems: 1. In desalination processes such as reverse osmosis, high pressure is required to force water through semipermeable membranes to separate salts and other minerals. This process requires large amounts of energy, especially on a large scale. 2- Membrane fouling: Organic matter, microorganisms, and water-soluble minerals can accumulate on the surface of membranes, causing fouling. This reduces the efficiency of the treatment process and increases the pressure required for treatment. Deposits can lead to a reduction in the useful life of membranes, requiring their cleaning or early replacement. 3. Increasing production capacity in desalination processes means increasing construction, maintenance, and energy costs. For communities that need more purified water, this can be a major challenge. Planning for expansion and renovations can be difficult and time-consuming, especially in remote or less developed areas. 4- High maintenance costs: There is a need for regular inspection and replacement of components such as membranes, pumps, and control valves, all of which require regular maintenance periods. Consumables such as chemicals for cleaning membranes also need to be supplied regularly, which can result in significant ongoing costs. Statement of the objectives of the invention: 1- Reducing energy consumption based on general principles in design and manufacturing techniques (in the simulated example, the device has a radius of 15 cm with an energy consumption range) 2- Reducing manufacturing costs by relying on the lack of use of high-tech manufacturing equipment (such as nanotechnology membranes used in reverse osmosis and electrodialysis) 3- Lack of membrane fouling and reduced efficiency due to not using a membrane in the design 4- Longer lifespan of the new device compared to existing devices and no frequent need for high repair and maintenance costs based on design principles 5- Increasing efficiency and effectiveness for use on large and industrial scales 6- Simple design and construction so that it can be made available to all countries (including developing countries). A description of the state of the prior art and the history of developments related to the claimed invention. 1- The electrodialysis method is a method in which there are parallel membranes between two electrodes that have the ability to pass positive and negative ions, so by applying voltage to the two ends of the electrodes, channels are formed between the membranes that contain water with a low salt concentration and with a high salt concentration. This method was first used in 1940 and has now become more efficient over time with the advancement of technology and the manufacture of membranes with better efficiency. Compared to the claimed design, this method only uses an electric field and also uses membranes to separate ions, while in the claimed method we do not need a membrane. Also, instead of using a uniform electric field applied to the electrodes, an alternating electric field is used to minimize the amount of water decomposition, and the magnetic field, along with the electric field, will be responsible for separating the ions in the solution. 2- In the patent number WO / 2003 / 048050 in 2003, the use of a magnetic field to separate ions in a salt water solution is mentioned. This invention is the same as the electrodialysis method, with the difference that in the electrodialysis method, an electric field is used, but in this method, a magnetic field is used, and since the amount of force applied to the ion particles in the salt water solution depends on the perpendicular speed of the free ions in the solution relative to the magnetic field, its efficiency is much lower than that of the electrodialysis method. 3- In the patent number US 8,197,684 B2 in 2012, the use of magnetic fields for the water desalination process is mentioned. This device is formed of two hollow cylinders, the smaller cylinder is placed inside the larger cylinder. At the radius of the two cylinders, membranes are installed that are responsible for separating water with a high salt concentration and a low salt concentration. A magnetic field is created perpendicular to the speed of movement of the salt water solution in the channel, which in fact has a direct relationship to the rate of separation of the salt water concentration with its speed of passage. Compared to the claimed design, this invention only uses a magnetic field to separate ions and is only capable of separating free ions in the solution, and its efficiency and effectiveness will be very low, and it also requires a high-tech membrane to pass positive and negative ions for desalination. In contrast, the claimed design has a mechanism for ionizing the salt water solution using electrical pulses and ultimately a mechanism for separating free ions and ions created by the electric field in the channel.The claimed design does not require any membrane. 4- The use of magnetic fields for the water desalination process is mentioned in the patent number US 2004 / 0262234 A1 in 2004. The mechanism of this device is the same as the previous device, with only a slight difference in design, and overall their functionality is similar. 5- The use of a magnetic field for the water desalination process is mentioned in the patent number ES 1067217 U in 2007. The mechanism of this device is similar to the previous two devices, only its design is slightly different from them, and overall their function is the same. 6- The patent number WO 2017198225 A1 in 2017 refers to the use of a magnetic field for the water desalination process. The mechanism of this device is similar to the previous three devices, only its design is slightly different from them, and overall their function is the same. 7- The patent number WO 2014001741 A1 in 2014 refers to the use of a magnetic field for the water desalination process. The mechanism of this device is similar to the previous four devices, only its design is slightly different from them, and overall their function is the same. 8- In the patent number WO 2018 / 009616 A1 in 2018, the simultaneous use of magnetic and electric fields for the water desalination process is mentioned. In this invention, the concentration of ions, including salt, in water can be controlled with the help of modulated magnetic and electric fields and using at least one cathode and one anode, and also in this invention, the concentration of metal ions can be controlled using plasma current.Compared to the claimed design, this invention has a different function and has many design complexities due to the use of various parts. This method can be used on small scales, while the claimed design is used on large and industrial scales. In the claimed design, like this invention, modulated electric and magnetic fields can be used in proportion to the required concentration, but instead of using at least one pair of electrodes, several parallel electrodes are used, and the voltage applied to a number of them can be specified in such a way that the concentration of metal ions can also be controlled (by applying a high voltage to the solution, i.e., the plasma current). 9- In the patent number 1CN 108163938 A in 2018, the use of a magnetic field to separate ions in a salt water solution is mentioned. In this device, the salt water solution is first ionized in the ionization chamber under high electric voltage, then the ionized solution passes through a magnetic field at a speed through a thin nozzle, and the ions present are each deflected in a direction under the influence of the magnetic field. Compared to the claimed design, the efficiency and energy consumption will be much higher because the amount of force applied to the ions will have a direct relationship with their speed of movement, and speeding up the salt water solution requires high energy consumption, but in the claimed design, the speed of the magnetic field is independent of the speed of movement of the ions, which in itself causes a significant reduction in energy consumption, and the overall structure is very different from the claimed design. 10- Patent No. US10046991B2 from 2017 refers to the use of a magnetic field to separate free ions in a salt water solution. In this design, a cell is placed between two rare earth magnets. As the salt water solution passes through this cell, depending on the flow rate of the solution, the free ions in the solution move towards the side holes of the channel under the influence of the force applied by the magnetic field and exit from them, thus separating the free ions from the solution. In comparison to the claimed design, it should be acknowledged that in this design, the salt water solution in a channel is ionized by an alternating electric voltage, and instead of the perpendicular movement of the salt water solution to apply force to the ions in it, the rotating magnetic field created by the coils embedded in the stator, with its relative movement to the ions formed in the solution, causes force and separates them from the solution. Since the speed of rotation of the magnetic field can be very high, it will be much more efficient in applying force to the ions in the solution compared to the movement of water in the channel. 11- Patent number EP2792644B1 in 2019 describes a saltwater purification system that operates based on electrochemical processes. The system uses two types of electrodes: one to absorb negative ions and the other to absorb positive ions. When voltage is applied to the electrodes, negative ions such as chloride move through an ion exchange membrane towards the redox electrode, while positive ions such as sodium move towards the other electrode containing manganese dioxide and are absorbed. This process helps reduce the amount of salt in the water. In comparison, the claimed design uses an alternating electric field to ionize the solution and separates the ions formed in the solution by applying a rotating magnetic field. 12- In a conference paper at https: / / civilica.com / doc / 1568026 / entitled "Investigating the possibility of separating salt particles from seawater using the excitability of salt particles under a magnetic field", the use of a magnetic field to separate free ions in a brine solution is mentioned. This method, like the previous inventions we mentioned, only uses a magnetic field to separate free ions in the solution, and the amount of this separation is proportional to the speed of movement of free ions in the brine solution perpendicular to the direction of the magnetic field, while the claimed design includes an ionization system using an alternating electric field that ionizes the brine solution. Also, a rotating magnetic field that is created by a stator and a special coil and has the ability to adjust the rotation speed, acts to salt the solution by applying force to the ions created in it. Depending on the intensity of the electric and magnetic fields, as well as the speed of rotation of the magnetic field, the final concentration of the desalinated water can be changed and controlled. Providing a solution to an existing technical problem along with an accurate, sufficient, and integrated description of the invention First, a few explanations are needed regarding the fundamental principles used in this invention. As we know, charged particles are subjected to a force under the influence of magnetic and electric fields, the amount of which can be measured through the following equation: (1) According to equation (1), the amount of force is directly related to the intensity of the magnetic and electric fields, the charge of the particle, and the speed of movement of the charged particle in the magnetic field. Therefore, if we want to increase the force exerted on a charged particle under these conditions, it is sufficient to increase any of the factors mentioned. Another topic that should be considered in this section is the study of the behavior of salt water solution under the influence of an electric field caused by applying a voltage to the electrodes in it. Based on the following relationship, the distribution function of the electric charge density of ions in a channel with width L (Figure q2) can be defined as follows: (2) Which for relation (2) we have: (3) (4) (5) And the constants of the above relation are as follows: , , , Now, by substituting arbitrary values ​​such as the initial concentration of free ions (), temperature (), time (t), channel length (L), and anode voltage (, assuming zero cathode voltage), we can observe the electric charge density distribution function of charged particles along the channel, and it is clearly evident that the density of charged particles at an arbitrary time near the electrodes is much higher than at other points in the channel. To better understand this, the electric charge density distribution function along the channel is plotted for specific values ​​(Figure s1). Considering the topics that have been briefly discussed so far, we can obtain a relationship for the drift velocity of ions in a salt water solution under the influence of an electric field and a rotating magnetic field. The drift velocity for a positive ion () will be as follows: (6) In the above equation, B is the magnetic flux density, the speed of movement of the salt water solution in the channel, e is the electric charge of the electron (), vis is the viscosity of the salt water, the ion radius, the linear speed of the rotating magnetic field, and the speed due to the concentration gradient, which is defined as follows: (7) which in equation (7) is Avogadro's number. It should be noted that the drift velocity for negative ions () is the same as equation (6) except that its sign is negative. Figure (s2) shows the drift velocity for positive ions with certain parameters along the channel. Now we can obtain the vertical component of the velocity of salt ions in the channel, which will be as follows:(8) In fact, the magnitude of the ion velocity in the horizontal component (x-axis) is so small that it can be ignored and the magnitude of the velocity in the vertical direction can be considered equal to the magnitude of the total velocity (Equation 7). The items mentioned in the previous section are the fundamentals that were mentioned to confirm the fundamental principles of the device's operation in theory, now we can look at the operation of this invention and examine it. In general, this design consists of two main parts: 1- Channels compartment (4) 2- Stator (axial flux type) (3) The channel housing consists of a main channel (2) (made of plastic, polymer, PVC or any usable material that is electrically insulating) with a width and height of 5 mm (with a wall thickness of 0.1 to 0.5 mm) which is designed in the form of a spiral with a desired length (depending on the radius of the stators). The radius of this spiral can be from a few centimeters to several meters, which will vary depending on the type of use (industrial, semi-industrial or domestic function). The empty space between this spiral is also divided by a separator (11) into two smaller sub-channels (13). The main channel (2) includes an inlet and an outlet, while the sub-channels (13) are ultimately connected and have only one outlet because their inlets are actually grooves (16) embedded in the main channel (2) that transfer the concentrated salt water solution on the side walls of the main channel (2) to the sub-channels (13) by means of protrusions (18).Inside the main channel (2), a set of electrodes (17) made of graphite is embedded on the wall surfaces of the main channel (2). These electrodes (17) are connected in series, meaning that the anodes are connected in series along the channel by an insulated flat wire (14) and the cathodes are connected together (15) and an alternating voltage (pulse) is applied along the channel to the salt water solution. Along the channel, there are protrusions (18) of a certain length that, through a groove (16), are responsible for collecting and transferring the salt solution moving in the channels of the channel wall (the same wall where the electrodes (17) are embedded) to the sub-channels. Assuming zero static pressure of the salt solution inside the channel and considering a desired velocity for the salt solution inside the channel, the length of the protrusion (18) will have a direct relationship with the rate of transfer of the salt solution to the sub-channels (13). On both sides of the channel housing, stators (3) with an axial flux structure are installed, which are responsible for creating a rotating magnetic field. The magnetic field rotates in only one direction on the channel, so unlike conventional stators (3), this stator will be unidirectional. For this purpose, a special winding is required (Figure 1f) and the use of a three-phase half-wave rectifier (Figure q1) at the stator input (3). The brine solution enters the main channel (2) through a pump (1) (it should be noted that the incoming brine solution is considered free of floating particles such as mud, rocks, sand, etc.). The pump (1) is only responsible for circulating the brine solution in the main channel (2), so its static pressure is considered zero. After entering the main channel (2), the solution is affected by an alternating voltage (pulse) (Figure q1) applied to the electrodes (17), and the amount of current flowing through the solution can be controlled and its size is considered to be as small as possible (depending on the length of the channel, from a few microamperes to a few hundred milliamperes). This is because of the reduction in the rate of decomposition of the brine solution. Due to this alternating voltage (pulse), the salt water solution begins to ionize, and also under the influence of the alternating electric field (pulse), the ions created and the existing ions begin to move towards the electrodes (17) located on the sides of the main channel (2) (positive ions move towards the cathode and negative ions towards the anode).On the other hand, the rotating magnetic field created by the stators (3) also exerts force on the ions in the salt water solution, directing them towards the channel walls (the walls on which the electrodes (17) and protrusions are embedded) (the direction of the field and the rotational movement is in a direction that facilitates the movement of the ions towards the channel walls), so the solution on the sides of the channel becomes more concentrated than the central points. On the other hand, as the solution moves in the main channel (2) and passes through the protrusions (18) embedded in the sides of the main channel (2), the more concentrated parts are transferred to the sub-channels on both sides of the main channel, and over time, the salt water solution in the channel becomes more and more diluted until it finally reaches the desired concentration and exits from the main channel outlet. The more concentrated brine solution in the subchannels is also eventually discharged through the outlet of the subchannel. The subchannel is therefore divided into two parts by a positive and negative ion separating wall (11) to prevent ions discharged from one side of the main channel (2) from entering the other side. At the outlet of the main channel (2) and also the sub-channel (13), there is a solenoid valve (7 and 8) that can, through a transfer pipe (5), once again direct the salt water solution with a lower concentration (at the outlet of the main channel (2)) and the salt water solution with a higher concentration (at the outlet of the sub-channel (13)) towards the inlet of the main channel (2) so that this process is repeated once more until the required concentration is finally reached. Explanation of shapes, maps and diagrams 1- Electric pump to move the salt water solution in the main channel (without static pressure) 2- Main channel 3- Axial flux type stator 4- Channels compartment 5- Return pipe from the main channel outlet and the sub-channel outlet to the main channel inlet 6- Subchannel output 7- Electric valve connecting the main channel outlet to the main channel inlet 8- Electric valve connecting the outlet of the sub-channel to the inlet of the main channel 9- Main channel output 10- Sub-channel top layer 11- Wall separating positive and negative ions 12- Sub-channel bottom layer 13- Subchannel 14- Flat wire with insulating coating connecting series anodes 15- Flat wire with insulating coating connecting series cathodes 16- Grooves that transfer salt water solution from the main channel to the secondary channel 17- Graphite electrode 18- Protrusions embedded in the wall of the main channel q1- Schematic of electrical circuits for stator and electrodes q2- Distribution of salt ion marker in a channel with an applied electric field in the y direction and a rotating magnetic field in the -z direction with width W, length L, and height H q3- The figure shows the behavior of ions in a channel five millimeters wide and five millimeters high and one centimeter long. s1- Three-dimensional graph of the charge density distribution function in a channel of length L with parameters specified in terms of position y and time t s2- Three-dimensional diagram of the drift velocity of a positive salt ion () in a channel of length L with parameters specified in terms of position y and time t f1- Stator winding to create a rotating magnetic field with the same direction and examine it in three different phases c1- Simulation of the concentration distribution of a salt water solution with parameters similar to those in graphs s1 and s2 in a channel with a width and height of five millimeters and a length of one centimeter in COMSOL software 2c- Simulating the velocity distribution of a medium-velocity salt water solution with parameters similar to those in the s1 and s2 diagrams in a channel with a width and height of five millimeters and a length of one centimeter in COMSOL software. c3- Simulate the distribution of electric current passing through the width of the channel by electrodes with parameters similar to those in the s1 and s2 diagrams in a channel with a width and height of five millimeters and a length of one centimeter in the COMSOL software. 4c- Simulation of the distribution of electric potential resulting from applying voltage to electrodes with parameters similar to the s1 and s2 diagrams in a channel with a width and height of five millimeters and a length of one centimeter in COMSOL software. A clear and precise statement of the advantages of the claimed invention over prior inventions. 1- Reduced energy consumption to produce a given volume of fresh water compared to existing devices 2- Reduced construction costs due to the lack of use of expensive equipment with high-tech construction. 3- Reduced maintenance costs due to not using any types of membranes in this device compared to reverse osmosis and electrodialysis methods. 4- The ability to control the intensity of the applied magnetic and electric fields, as well as the speed of rotation of the magnetic field, proportional to the final concentration level, by microcontrollers. 5- Possibility of manufacturing on various scales (industrial, semi-industrial and domestic) according to consumer demand 6- Possibility of connecting devices in series and parallel to each other to increase efficiency and productivity. Description of at least one implementation method for implementing the invention On land, this device can be used on a large, industrial scale to desalinate seawater and produce fresh water for use in agriculture, industry, or drinking. At sea, on a smaller scale, this device can be used to produce fresh water for use by personnel on ships and oil platforms. Explicit mention of the industrial application of the invention This invention can be used in the marine, shipping, water supply, and any industry that needs to produce fresh water from salt water.

Claims

Claim What is claimed: Claim 1) What is claimed is a desalination device that, by simultaneously applying alternating electric voltage (pulse) by existing electrodes and a rotating magnetic field using an axial flux type stator to the salt water solution along a channel of desired length, width and height, separates the ions created and present in the salt water solution in order to desalinate it. The components of this device are: - Two parallel axial flux type stators to create a rotating magnetic field in the channel chamber - A main channel with a width and height of 5 mm with a desired length in a spiral - A secondary channel with a separating layer between the empty space of the main channel - A low-pressure pump for the flow of the salt water solution in the main channel - Electric valves connected to the inlet of the main channel on the outlet of the main channel and the secondary channel Claim 2) According to claim 1, by using a three-phase power supply and a half-wave rectifier and a specific type of winding, a unidirectional rotating magnetic field is created inside the main channel, the intensity and speed of which can be determined in proportion to the required concentration of the desalinated solution. Claim 3) According to claim 1, the main channel has graphite electrodes and grooves with protrusions of a certain size along the length of the channel, which are responsible for ionizing the salt water solution and separating the ions in the salt water solution, respectively. Claim 4) According to claim 3, the alternating voltage (pulse) applied to the electrodes has a specific pulse width and a specific frequency, the voltage of which can vary slightly depending on the degree of ionization of the salt water solution, and the amount of current passing through the electrodes can also be controlled. Claim 5) According to claim number 3, in addition to ionizing the salt water solution, the electrodes also cause the existing ions to drift and move towards the channel walls, i.e. the places where the electrodes are installed. Claim 6) According to claim 1, the separating layer in the sub-channel is responsible for separating the positive and negative ions in the salt water solution and preventing them from returning to the main channel in the adjacent parts.

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