Wastewater evaporation and concentration system

Abstract

The invention relates to a wastewater evaporation and concentration system, which comprises a separator, a heater and a multi-effect separator, the separator is provided with an inlet end, and the inlet end is used for inputting a wastewater stock solution; the input end of the heater is connected with the output end of the separator, and the heater is used for heating the wastewater stock solution; the multi-effect separator comprises a plurality of chambers, the plurality of chambers are sequentially connected in series and communicated, and the bottom of each chamber is used for accommodating a wastewater stock solution; the first cavity is communicated with the output end of the heater, the last cavity is communicated with the separator, and the multi-effect separator is used for evaporating and separating water in the wastewater stock solution. By arranging the multi-effect separator and the heat exchanger, a multi-section gradient heat exchange structure is formed, heat energy of a heat exchange medium is fully utilized, heat loss is reduced, and energy consumption is reduced.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and more specifically to a wastewater evaporation and concentration system. Background Technology

[0002] In industrial production, desulfurization wastewater is an inevitable byproduct of desulfurization processes in industries such as thermal power generation, steel smelting, and chemical production. Its water composition is complex and its pollution load is high, containing high concentrations of salts (such as chlorides, sulfates, and heavy metal ions), suspended solids, and various recalcitrant pollutants. Direct discharge would cause serious damage to soil and aquatic ecosystems, and even endanger human health; while direct entry into subsequent advanced treatment stages without concentration treatment would significantly increase the difficulty and cost of treatment.

[0003] Currently, the mainstream wastewater concentration technology in industry is mainly evaporation concentration. The core principle is to evaporate the water in the wastewater by heating, thereby separating the solute and solvent and achieving the purpose of concentration and volume reduction.

[0004] Traditional wastewater concentration processes often rely on single-effect evaporation. Single-effect evaporation technology completes water separation through a single evaporation unit. After the heating steam exchanges heat with the wastewater once, a large amount of high-temperature condensate is directly discharged, and the secondary steam is not effectively recovered, resulting in extremely low thermal energy utilization and serious energy waste. Summary of the Invention

[0005] In view of the above problems, the present invention provides a wastewater evaporation and concentration system to solve the problems of high energy consumption and low energy utilization efficiency of traditional wastewater evaporation and concentration.

[0006] To achieve the above objectives, the applicant provides a wastewater evaporation and concentration system, comprising: A separator, wherein the separator is provided with an inlet end, the inlet end being used to input raw wastewater solution; A heater, the input end of which is connected to the output end of the separator, is used to heat the raw wastewater solution; A multi-effect separator includes multiple chambers connected in series, with the bottom of each chamber used to hold raw wastewater. The first chamber is connected to the output of the heater, and the last chamber is connected to the separator. The multi-effect separator is used to evaporate and separate water from the raw wastewater.

[0007] Furthermore, it also includes: a heat exchanger that sequentially passes through the plurality of chambers and is positioned above the chambers, the input end of the heat exchanger being connected to the separator, and the output end of the heat exchanger being connected to the input end of the heater.

[0008] Furthermore, the input end of the heat exchanger is positioned above the last chamber, and the output end of the heat exchanger is positioned above the first chamber.

[0009] Furthermore, it also includes: a circulation pump, which is placed on the pipeline connecting the separator and the heat exchanger to input the wastewater raw solution into the heat exchanger.

[0010] Furthermore, it also includes a condenser; a collection port is provided at the top of the plurality of chambers and the top of the separator, and the plurality of collection ports are connected to the condenser to cool wastewater vapor to form condensate.

[0011] Furthermore, it also includes: a condenser tank, which is connected to the condenser, and the condenser tank is used to collect condensate from the condenser; A vacuum pump, which is connected to the condenser tank, is used to extract air from the chamber, condenser, condenser tank, and separator.

[0012] Furthermore, it also includes: a discharge pump, which is connected to the separator, and the discharge pump is used to discharge the concentrated wastewater raw liquid in the separator; A condensate return pump is connected to the condensate tank and is used to drain the condensate from the condensate tank.

[0013] Furthermore, the heater includes: a heating pipe and a wastewater pipe; The input end of the wastewater pipeline is connected to the output end of the separator, and the output end of the wastewater pipeline is connected to the multi-effect separator; the heating pipeline is placed on one side of the wastewater pipeline, and the heating pipeline is used to heat the wastewater pipeline; the heating pipeline is connected to the heat source supply unit.

[0014] The advantages of the above technical solution compared to existing technologies are as follows: By setting up a multi-effect separator and a heat exchanger, the present invention forms a multi-stage gradient heat exchange structure to fully utilize the thermal energy of the heat exchange medium, reduce heat loss, and reduce energy consumption; by using a vacuum pump, the boiling point of the wastewater is lowered, so that the wastewater raw liquid evaporates at a low boiling point (45-65℃), which can not only accelerate the rate of wastewater evaporation and concentration and improve working efficiency, but also avoid low-boiling-point substances (such as organic matter) from evaporating simultaneously at high temperatures, and slow down equipment scaling and extend the operating cycle.

[0015] The above description of the invention is merely an overview of the technical solution of the present invention. In order to enable those skilled in the art to better understand the technical solution of the present invention and to implement it based on the description and drawings, and to make the above-mentioned objectives and other objectives, features and advantages of the present invention easier to understand, the following description is provided in conjunction with the specific embodiments and drawings of the present invention. Attached Figure Description

[0016] The accompanying drawings are only used to illustrate the principles, implementation methods, applications, features, and effects of specific embodiments of the present invention and other related contents, and should not be considered as limitations on the present invention.

[0017] In the accompanying drawings of the instruction manual: Figure 1 This is a flowchart of the process of the present invention.

[0018] The reference numerals used in the above figures are explained as follows: 1. Condenser; 2. Separator; 21. Inlet end; 3. Heater; 4. Multi-effect separator; 41. Chamber; 5. Heat exchanger; 6. Circulating pump; 7. Condensate tank; 8. Vacuum pump; 9. Discharge pump; 12. Heating pipeline; 13. Wastewater pipeline; 14. Heat source supply unit; 15. Feed pump; 16. Condensate return pump. Detailed Implementation

[0019] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this invention in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this invention and are therefore intended only as examples, not as limiting the scope of protection of this invention.

[0020] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this invention, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0021] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit the invention.

[0022] In the description of this invention, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " generally indicates that the preceding and following objects have an "or" logical relationship.

[0023] In this invention, terms such as “first” and “second” are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy, or order between these entities or operations.

[0024] Without further limitations, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this invention is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0025] In this invention, expressions such as "greater than", "less than", and "exceeding" are understood to exclude the stated number; expressions such as "above", "below", and "within" are understood to include the stated number. Furthermore, in the description of the embodiments of this invention, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times", unless otherwise explicitly specified.

[0026] In the description of the embodiments of the present invention, the spatial related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of the present invention or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0027] Unless otherwise explicitly stated or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this invention, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral arrangement; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this invention according to the specific circumstances.

[0028] Please see Figure 1This embodiment provides a wastewater evaporation and concentration system, including: Separator 2, wherein the separator 2 is provided with an inlet end 21, the inlet end 21 being used to input raw wastewater; Heater 3, the input end of which is connected to the output end of the separator 2, is used to heat the wastewater raw liquid; The multi-effect separator 4 includes multiple chambers 41, which are connected in series and connected in a series. The bottom of each chamber 41 is used to contain the wastewater raw liquid. The first chamber 41 is connected to the output end of the heater 3, and the last chamber 41 is connected to the separator 2. The multi-effect separator 4 is used to evaporate and separate water from the wastewater raw liquid.

[0029] The inlet end 21 of the separator 2 is connected to the feed pump 15 through a pipe. The feed pump 15 pumps the wastewater raw liquid into the separator 2 according to the set flow rate. The separator 2 is used to store the wastewater raw liquid and evaporate and concentrate it. An opening can be provided at the top of the separator 2 for extracting steam from the separator 2.

[0030] After being evaporated and concentrated by separator 2, the wastewater concentrate enters heater 3 from the output end of separator 2 through the conveying end of heater 3. Specifically, separator 2 is connected to heater 3 through a pipe. Heater 3 has a pipeline inside, and the wastewater concentrate flows in the pipeline. A heating source is provided outside the pipeline to heat the wastewater concentrate obtained in the pipeline. The heating source can be hot water from the plant area. Specifically, in this embodiment, the heat source of the heater comes from the plant area hot water supply system.

[0031] Preferably, the multi-effect separator 4 has four chambers 41 arranged sequentially, and the overflow pipes of each chamber 41 are connected in series. Each chamber 41 can hold heated wastewater raw liquid so that the wastewater raw liquid can be evaporated and concentrated in the chamber 41. The multi-effect separator 4 is connected to the heater 3 and the separator 2 through pipelines respectively.

[0032] Specifically, ambient temperature wastewater raw liquid is temporarily stored in separator 2 through inlet 21. The wastewater raw liquid in separator 2 can be evaporated and concentrated to reduce its content. Separator 2 stably delivers the wastewater raw liquid to the pipeline of heater 3. Heater 3 is supplied with 90°C high-temperature hot water. Through indirect heat exchange, the temperature of the wastewater raw liquid in the pipeline is raised to 80°C. The wastewater raw liquid is then delivered through the pipeline to the first chamber 41 of multi-effect separator 4. At this time, the temperature of the wastewater raw liquid is 70°C. Under negative pressure, the wastewater raw liquid evaporates rapidly to generate steam that flows to the top of chamber 41. At the same time, the wastewater raw liquid flows through the overflow pipe to the subsequent chambers 41 in sequence until the last chamber 41, where the temperature of the wastewater raw liquid is 55°C.

[0033] After the wastewater raw liquid undergoes multiple evaporation and concentration processes in the multi-effect separator 4, it flows back into the separator 2 through a pipeline. At this point, the wastewater raw liquid is cooled to 45°C through the pipeline, and then continues to evaporate and concentrate.

[0034] The wastewater raw liquid flowing back into separator 2 re-enters heater 3 and circulates continuously. When the wastewater raw liquid is concentrated to a preset value, it can be discharged from separator 2.

[0035] Please see Figure 1 In this embodiment, it further includes a heat exchanger 5, which passes through multiple chambers 41 in sequence and is positioned above the chambers 41. The input end of the heat exchanger 5 is connected to the separator 2, and the output end of the heat exchanger 5 is connected to the input end of the heater 3.

[0036] Heat exchanger 5 is a coil-type heat exchanger. The coil material can be 2507 duplex stainless steel, which has strong corrosion resistance and can effectively adapt to high-salt wastewater environment. Heat exchanger 5 is connected to separator 2 and heater 3 flanges through pipes respectively.

[0037] The heat exchanger 5 is sequentially installed into the chamber 41 of the multi-effect separator 4 and located above the chamber 41 so as to exchange heat with the hot steam in the chamber 41 and heat the raw wastewater in the coil.

[0038] The flow direction of the raw wastewater in the heat exchanger 5 is opposite to that in the multi-effect separator 4, so as to better utilize the hot steam in the chamber 41 to heat the raw wastewater in the coil, thereby reducing heat loss, improving heat exchange efficiency, and reducing energy consumption.

[0039] Specifically, each chamber 41 in the multi-effect separator 4 heats the raw wastewater in the heat exchanger 5 in sequence. The temperature in the last chamber 41 of the multi-effect separator 4 is 55°C, and the generated hot steam heats the raw wastewater in the heat exchanger 5 from 45°C to 50°C. The remaining chambers 41 heat the raw wastewater in the heat exchanger 5 to 55°C, 60°C, and 65°C in sequence, which greatly improves the waste heat utilization rate in the multi-effect separator 4, thereby reducing the heating pressure of the heater 3 and reducing energy consumption.

[0040] Please see Figure 1 In this embodiment, the input end of the heat exchanger 5 is positioned above the last chamber 41, and the output end of the heat exchanger 5 is positioned above the first chamber 41. This arrangement reduces heat exchange between the chamber 41 and the outside environment, increasing the heat utilization rate of the equipment.

[0041] Please see Figure 1In this embodiment, it also includes a circulation pump 6, which is placed on the pipeline connecting the separator 2 and the heat exchanger 5 to input wastewater raw liquid into the heat exchanger 5.

[0042] The circulating pump 6 can be a centrifugal pump with good corrosion resistance, which can resist acid and alkali corrosion and salt corrosion, improve the service life of the equipment and reduce the failure rate.

[0043] The circulating pump 6 is connected to the separator 2 and the heat exchanger 5 through pipelines to extract the raw wastewater in the separator 2 and transport it to the heat exchanger 5.

[0044] Please see Figure 1 In this embodiment, a condenser 1 is also included; a collection port is provided on the top of the plurality of chambers 41 and the top of the separator 2 respectively, and the plurality of collection ports are connected to the condenser 1 to cool wastewater vapor to form condensate.

[0045] The collection port is a flange-type structure made of stainless steel, used to output the hot steam in chamber 41 and separator 2 to condenser 1 through a pipeline.

[0046] Meanwhile, an aluminum silicate cotton insulation layer can be wrapped around the outside of the pipe to reduce heat exchange between the hot steam inside the pipe and the outside, thereby reducing heat loss.

[0047] Please see Figure 1 In this embodiment, it further includes: a condenser tank 7, which is connected to the condenser 1, and the condenser tank 7 is used to collect condensate in the condenser 1; Vacuum pump 8 is connected to condenser tank 7. Vacuum pump 8 is used to extract air from chamber 41, condenser 1, condenser tank 7 and separator 2 to create negative pressure inside them.

[0048] The condenser tank 7 is connected to the condenser 1 through a pipeline. The condensate in the condenser 1 flows into the condenser tank 7 through the pipeline. The steam in the condenser 1 enters the condenser tank 7 after heat exchange and condensation. The condensate enters the condenser tank 7 for temporary storage. The level gauge enables interlocking and automatic control. The condensate is discharged to the production reuse location by the condensate return water pump 16.

[0049] Vacuum pump 8 can be a water ring type vacuum pump 8, which is connected to the top of condenser 7 through a sealed pipeline, and a check valve and a vacuum gauge are installed in the pipeline to monitor the system vacuum level in real time.

[0050] The vacuum pump 8 is set up to extract air from each chamber 41 of the multi-effect separator 4, so as to lower the boiling point of the wastewater raw liquid, increase the evaporation rate, increase the evaporation amount, improve the evaporation and concentration rate of the wastewater raw liquid, improve the working efficiency of the system, and avoid the simultaneous evaporation of low-boiling-point substances (such as organic matter) in the wastewater raw liquid caused by high-temperature evaporation.

[0051] Please see Figure 1 In this embodiment, the system further includes: a discharge pump 9, which is connected to the separator 2 and is used to discharge the concentrated wastewater concentrate from the separator 2; and a condensate return pump 16, which is connected to the condensate tank 7 and is used to discharge the condensate from the condensate tank 7. The discharge pump 9 can be a wear-resistant and corrosion-resistant screw pump, which is connected to the discharge port flange of the separator 2 through a pipeline. When the wastewater raw liquid in the separator 2 is concentrated to the preset value, the discharge pump 9 is started to extract the wastewater raw liquid in the separator 2 for subsequent treatment.

[0052] Please see Figure 1 In this embodiment, the heater 3 includes a heating pipe 12 and a wastewater pipe 13; The input end of the wastewater pipeline 13 is connected to the output end of the separator 2, and the output end of the wastewater pipeline 13 is connected to the multi-effect separator 4; the heating pipeline 12 is placed on one side of the wastewater pipeline 13, and the heating pipeline 12 is used to heat the wastewater pipeline 13; the heating pipeline 12 is connected to the heat source supply unit 14.

[0053] The heating pipe 12 can be made of high-temperature resistant 304 stainless steel, and the wastewater pipe 13 can be made of corrosion-resistant 2507 duplex stainless steel. The heating pipe 12 can be arranged parallel to one side of the wastewater pipe 13; or, the heating pipe 12 can be wound around the outside of the wastewater pipe 13. Specifically, the raw wastewater flows out from the separator 2, enters the heater 3 through the wastewater pipe 13, and the heating medium in the heating pipe 12 exchanges heat with the raw wastewater in the wastewater pipe 13 to heat the raw wastewater.

[0054] The heating medium in heating pipe 12 is from the plant's hot water supply system. Specifically, heat source supply unit 14 can provide hot water from the plant's low-temperature economizer. Hot water is provided by recovering waste heat from the boiler tail flue gas through the low-temperature economizer to heat the raw wastewater.

[0055] The workflow of this invention is as follows: (1) Start the circulating cooling water supply and open the circulating cooling water supply valve and return valve of the condenser 1.

[0056] (2) Start the feed pump 15, open the relevant valves and adjust the feed flow rate to pump the wastewater raw liquid to the separator 2; when the liquid level of the separator 2 reaches the set position, stop feeding.

[0057] (3) Start vacuum pump 8 to draw a vacuum. Before starting, ensure that the feed, discharge and reflux regulating valves are closed and set the vacuum degree to -0.095MPa.

[0058] (4) When the system vacuum reaches about -0.05MPa, turn on the circulation pump 6 and open the corresponding valves in the hot water supply inlet and return water storage tank of the heating equipment at the same time; at the same time, control the liquid level of the separator 2 at the set position, and the highest liquid level of the separator 2 shall not exceed the set position.

[0059] (5) The condensate generated by the system enters the condensate tank 7, and is automatically controlled by the level gauge interlock. The condensate is then discharged to the production reuse location by the condensate return water pump 16.

[0060] (6) When the wastewater in separator 2 reaches a certain concentration, the concentrated liquid in separator 2 is transported to the high-temperature crystallizer via discharge pump 9. The inlet and outlet flow rates of feed pump 15 and discharge pump 9 are adjusted according to the system's designed concentration ratio. (For example, if the system's concentration ratio is designed to be 5 times, and the designed inlet flow rate of feed pump 15 is 1 t / h, then the outlet flow rate of discharge pump 9 is 0.2 t / h, and the evaporation rate is 0.8 t / h. The system operates at these inlet and outlet flow rates. As long as the liquid level in separator 2 does not exceed the system's set ultra-high liquid level or ultra-low liquid level, the system will operate automatically.) Finally, it should be noted that although the above embodiments have been described in the description and drawings of this invention, this should not limit the scope of patent protection of this invention. Any technical solutions that are based on the essential concept of this invention, utilize the content described in the description and drawings of this invention to make equivalent structural or procedural substitutions or modifications, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of patent protection of this invention.

Claims

1. A wastewater evaporation and concentration system, characterized in that, include: A separator, wherein the separator is provided with an inlet end, the inlet end being used to input raw wastewater solution; A heater, the input end of which is connected to the output end of the separator, is used to heat the raw wastewater solution; A multi-effect separator includes multiple chambers connected in series, with the bottom of each chamber used to hold raw wastewater. The first chamber is connected to the output of the heater, and the last chamber is connected to the separator. The multi-effect separator is used to evaporate and separate water from the raw wastewater.

2. The wastewater evaporation and concentration system according to claim 1, characterized in that, Also includes: A heat exchanger that sequentially passes through multiple chambers and is positioned above the chambers, with its input end connected to the separator and its output end connected to the input end of the heater.

3. The wastewater evaporation and concentration system according to claim 2, characterized in that, The input end of the heat exchanger is positioned above the last chamber, and the output end of the heat exchanger is positioned above the first chamber.

4. The wastewater evaporation and concentration system according to claim 2, characterized in that, Also includes: A circulating pump is placed on the pipeline connecting the separator and the heat exchanger to input raw wastewater into the heat exchanger.

5. The wastewater evaporation and concentration system according to claim 1, characterized in that, It also includes the condenser; Each of the multiple chambers and the separator is provided with a collection port at the top, and the multiple collection ports are connected to the condenser to cool wastewater vapor and form condensate.

6. The wastewater evaporation and concentration system according to claim 5, characterized in that, Also includes: A condenser tank, which is connected to the condenser, is used to collect condensate from the condenser. A vacuum pump, which is connected to the condenser tank, is used to extract air from the chamber, condenser, condenser tank, and separator.

7. The wastewater evaporation and concentration system according to claim 6, characterized in that, Also includes: A discharge pump is connected to the separator and is used to discharge the concentrated wastewater raw liquid from the separator. A condensate return pump is connected to the condensate tank and is used to drain the condensate from the condensate tank.

8. The wastewater evaporation and concentration system according to claim 1, characterized in that, The heater includes: heating pipes and wastewater pipes; The input end of the wastewater pipeline is connected to the output end of the separator, and the output end of the wastewater pipeline is connected to the multi-effect separator; the heating pipeline is placed on one side of the wastewater pipeline, and the heating pipeline is used to heat the wastewater pipeline; The heating pipes are connected to the heat source supply unit.

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