WO2021169324A1

WO2021169324A1 - Energy-saving zero-emission low-temperature atmospheric pressure evaporation crystallization system and working method therefor

Info

Publication number: WO2021169324A1
Application number: PCT/CN2020/121316
Authority: WO
Inventors: 王晓龙; 郜时旺; 刘练波; 许世森
Original assignee: 中国华能集团清洁能源技术研究院有限公司
Priority date: 2020-02-25
Filing date: 2020-10-15
Publication date: 2021-09-02
Also published as: CN111153543A

Abstract

An energy-saving zero-emission low-temperature atmospheric pressure evaporation crystallization system and a working method therefor, belonging to the technical field of zero-emission of high-concentration brine. The system comprises an evaporation chamber (2), a crystallization kettle (4), an evaporative condensation heat exchanger (6), a condensation chamber (19) and a refrigeration chamber unit. Taking advantage of the different water-carrying capabilities of air at different temperatures, the circulation in the evaporation chamber (2) and the condensation chamber (19) realizes the concentration and crystallization of concentrated brine and the collection of a condensate, realizing zero-emission treatment of high-concentration brine under normal temperature and atmospheric pressure. The system has reasonable design, high degree of automation, low energy consumption, low costs, zero pollutant emission, high salinity and COD removal efficiency, and significant energy saving effect, and the concentrated brine is processed into solid salt and clean water. The system has good economic benefits, obvious environmental protection advantages, and good application prospects.

Description

Energy-saving zero-emission low-temperature atmospheric pressure evaporation crystallization system and working method thereof

Technical field

The invention belongs to the technical field of zero discharge of high-concentration brine, and specifically relates to an energy-saving zero-discharge low-temperature atmospheric pressure evaporation crystallization system and a working method thereof.

Background technique

Fresh water is the material basis for human survival. With the development of industrial civilization, the problem of high-concentration salt water discharged from seawater desalination and industrial production is becoming more and more serious. Evaporative concentration of solution is an important way to solve this problem. Traditional solution concentration methods include multi-stage flash evaporation, multi-effect evaporation, reverse osmosis and other methods. The process of multi-stage flash evaporation and multi-effect evaporation needs to consume a lot of steam; the reverse osmosis method needs to consume high-quality electric energy, and the operation and maintenance are complicated, and the cost is high. The traditional solution concentration method concentrates the salinity of the solution to over 6% and then discharges it directly into the environment, ignoring the impact of high-salinity solutions on the ecological environment of the surrounding seas in the long run. It can be seen that the traditional solution concentration method has high energy consumption and high pollution, and it is of great significance to develop a solution concentration process with low energy consumption, low cost and zero pollution emission.

Summary of the invention

In order to solve the above-mentioned shortcomings in the prior art, the purpose of the present invention is to provide an energy-saving zero-emission low-temperature atmospheric pressure evaporative crystallization system and its working method. The system design is reasonable and realizes the concentrated crystallization of concentrated brine and the collection of condensate. And zero discharge treatment of high concentration brine under normal temperature and pressure.

The present invention is realized through the following technical solutions:

The invention discloses an energy-saving zero-discharge low-temperature atmospheric evaporative crystallization system, which includes an evaporation chamber, a crystallization kettle, an evaporative condensation heat exchanger, a condensation chamber and a refrigeration chamber unit;

The top and bottom of the evaporation chamber and the condensing chamber are connected to form an annular gas circulation channel. The top of the evaporation chamber and the condensing chamber are connected with an insulating barrier. The lower part of the evaporation chamber and the condensing chamber is provided with a gas circulation fan, and the condensing chamber The side is provided with an air inlet, the air inlet surface of the gas circulation fan faces the air inlet, and the air outlet surface faces the evaporation chamber;

The inlet of the evaporation chamber is connected with a feed pump of concentrated brine. The evaporation chamber is equipped with an evaporation chamber sprayer and an evaporation chamber packing. The evaporation chamber sprayer is arranged above the evaporation chamber packing. The bottom outlet of the evaporation chamber is connected with the crystallization kettle. The brine feed pump is connected, the bottom side outlet of the evaporation chamber is connected with the hot side of the evaporative condensation heat exchanger, and the hot side of the evaporative condensation heat exchanger is connected with the evaporation chamber sprayer;

The condensing chamber is provided with a condensing chamber sprinkler and a condensing chamber packing. The condensing chamber sprinkler is arranged above the condensing chamber packing. The outlet at the bottom of the condensing chamber is connected with the hot end of the refrigeration chamber unit. The hot end of the refrigeration chamber unit is connected to the evaporative condensation heat exchanger. Cold side connection, the cold side of the evaporative condensation heat exchanger is connected with a condensing device, the condensing device is connected with the cold end of the refrigeration room unit, and the cold end of the refrigeration room unit is connected with the condensing chamber sprayer; the bottom side outlet of the condensing room is connected with a condensate discharge Tube.

Preferably, the refrigeration chamber unit includes a refrigeration chamber hot end heat exchanger, a throttle valve, a refrigeration chamber cold end heat exchanger, and a refrigeration chamber compressor, and the low boiling point working fluid is in the refrigeration chamber hot end heat exchanger and throttling valve. The valve, the cold end heat exchanger of the refrigeration chamber and the refrigeration chamber compressor circulate, the outlet at the bottom of the condensation chamber is connected with the hot end heat exchanger of the refrigeration chamber, and the hot end heat exchanger of the refrigeration chamber is connected with the cold side of the evaporative condensation heat exchanger; The device is connected with the cold end heat exchanger of the refrigeration chamber, and the cold end heat exchanger of the refrigeration chamber is connected with the condensing chamber sprayer.

Preferably, the condensing device is a condensing fan or a cooler.

Preferably, the connecting pipeline between the bottom outlet of the evaporation chamber and the crystallization kettle is provided with a concentrated brine discharge pump.

Preferably, the connecting pipeline between the bottom side outlet of the evaporation chamber and the hot side of the evaporative condensation heat exchanger is provided with a concentrated brine internal circulation pump.

Preferably, a condensate internal circulation pump is provided on the connecting pipeline between the bottom outlet of the condensing chamber and the hot end of the refrigerating chamber unit.

Preferably, a condensate drain pump is provided on the condensate drain pipe.

Preferably, a waste heat utilization heat exchanger is provided on the connecting pipeline between the hot side of the evaporative condensation heat exchanger and the evaporation chamber sprayer, and the waste heat utilization heat exchanger is connected to the external system.

Preferably, both the evaporation chamber sprinkler and the condensation chamber sprinkler are multilayered.

The invention discloses a working method of the energy-saving zero-emission low-temperature atmospheric evaporative crystallization system, which includes:

The concentrated brine enters the evaporation chamber through the concentrated brine feed pump, and the concentrated liquid at the bottom of the evaporation chamber enters the hot side of the evaporative condensation heat exchanger, and exchanges heat with the higher temperature condensate on the cold side of the evaporative condensation heat exchanger to become a high-temperature concentrated liquid. Sprayed from the sprayer of the evaporation chamber, in the filling area of the evaporation chamber, it is in reverse contact with the air sent from the gas circulation fan to cool down and returns to the bottom of the evaporation chamber. During the contact process, the moisture in the concentrated liquid is absorbed by the heated air, and the salt is in The concentrated liquid is retained; the concentrated liquid at the bottom of the evaporation chamber will continuously accumulate salinity and gradually approach the crystallization saturation concentration; the bottom concentrated liquid will enter the crystallization kettle from the bottom outlet of the evaporation chamber to achieve solid-liquid separation to obtain solid salt, and the turbid liquid in the crystallization kettle will return to the concentrated solution. Circulate after the brine feed pump;

The hot air with moisture enters the condensing chamber through the air inlet, and contacts with the spray liquid of the condensing chamber sprayer in the same direction to cool down in the filling area of the condensing chamber. During the cooling process, the moisture in the air condenses into condensate and falls; after the air cools down, it passes through the gas The circulating fan is sent to the evaporation chamber; the condensate accumulates at the bottom of the condensing chamber and enters the hot end of the refrigeration chamber from the outlet of the condensing chamber to exchange heat and increase the temperature. The heated condensate exchanges heat with the concentrated liquid in the evaporative condensation heat exchanger and then cools down. The cooled condensate passes through the condensing device to further reduce the temperature, and then exchanges heat in the cold end of the refrigeration chamber unit to cool again, and then the low-temperature condensate enters the condensing chamber sprayer; the accumulated condensate is used as the system output water and passes through the condensate discharge pipe Send out the system;

The air enters the condensing chamber from the air inlet under the action of the suction of the gas circulation fan, maintains the slightly positive pressure of the system, and circulates in the annular gas circulation channel formed by the evaporation chamber and the condensing chamber.

Compared with the prior art, the present invention has the following beneficial technical effects:

The invention discloses an energy-saving zero-emission low-temperature atmospheric pressure evaporation crystallization system, which includes an evaporation chamber, a crystallization kettle, an evaporation condensation heat exchanger, a condensation chamber, and a refrigeration chamber unit, which utilizes low temperature atmospheric pressure evaporation and crystallization, LAEC) working principle, simulating water evaporation and rainfall cycle in natural rainfall. In nature, airflow with a relative humidity of less than 100% can absorb moisture but not salt when passing over the ocean. When a supersaturated airflow is cold, it will condense and generate rainfall. LAEC technology simulates this natural phenomenon in a closed environment. When the gas is heated in the evaporation chamber and absorbs moisture, it condenses into pure water in the condensation chamber. This system uses the characteristics of different air temperature to carry different moisture capacity, and realizes the concentrated crystallization of concentrated brine and the collection of condensate through the circulation in the evaporation chamber and the condensing chamber, and realizes the zero discharge treatment of high-concentration brine under normal temperature and pressure. Use an external cold source (condensing device) to cool the condensate to maximize energy efficiency; spray and fill layers are used in the evaporation chamber and the condensation chamber to increase the effective gas-liquid contact area and enhance the mass transfer effect; the evaporation chamber and the condensation chamber The annular closed loop shape is adopted to reduce the resistance drop of the gas circulation. The system is reasonable in design and has the characteristics of low energy consumption, low cost, zero pollutant discharge, high salinity and COD removal efficiency, and significant energy-saving effects. The concentrated brine is processed into solid salt and clean water, which has obvious environmental advantages.

Further, the refrigeration chamber unit adopts a low-boiling point working fluid cycle to realize the transfer of heat from low temperature to high temperature, and can achieve a good treatment effect without external heat sources and cold sources, and realizes energy saving and consumption reduction.

Furthermore, the waste heat is introduced into the external system by the heat exchanger to heat the concentrated liquid, making full use of the remaining energy and maximizing energy efficiency.

Furthermore, the evaporation chamber sprayer and the condensation chamber sprayer are both multi-layered, which increases the effective contact area of gas and liquid and enhances the mass transfer effect.

The working method of the energy-saving zero-emission low-temperature atmospheric evaporative crystallization system disclosed in the present invention has high automation, low energy consumption, low cost, zero pollutant emission, high salinity and COD removal efficiency, and significant energy-saving effect. The concentrated brine is processed It is solid salt and clean water, with good economic benefits, obvious environmental protection advantages, and good application prospects.

Description of the drawings

Figure 1 is a schematic diagram of the overall structure of the energy-saving zero-emission low-temperature atmospheric pressure evaporative crystallization system of the present invention.

In the picture: 1-concentrated brine feed pump, 2-evaporation chamber, 3-concentrated brine discharge pump, 4-crystallization kettle, 5-concentrated brine internal circulation pump, 6-evaporation condensation heat exchanger, 7-waste heat utilization and exchange Heater, 8-gas circulation fan, 9-evaporation chamber sprayer, 10-evaporation chamber packing, 11-condensate internal circulation pump, 12-hot end heat exchanger of refrigeration chamber, 13-throttle valve, 14-refrigeration Room cold end heat exchanger, 15-refrigeration chamber compressor, 16-condensing fan, 17-condensation chamber sprayer, 18-condensation chamber packing, 19-condensation chamber, 20-condensate discharge pump.

Detailed ways

The following describes the present invention in further detail with reference to the accompanying drawings and specific embodiments, the content of which is to explain rather than limit the present invention:

As shown in Figure 1, the energy-saving zero-discharge low-temperature atmospheric evaporative crystallization system of the present invention includes an evaporating chamber 2, a crystallization kettle 4, an evaporative condensation heat exchanger 6, a condensation chamber 19, and a refrigeration chamber unit.

The top and bottom of the evaporation chamber 2 and the condensation chamber 19 are connected to form a ring-shaped gas circulation channel. The top of the evaporation chamber 2 and the condensation chamber 19 are connected with an insulating barrier. The insulating barrier can be silicate with a filter membrane. The partition reduces the heat exchange between the system and the outside. At the same time, gas and water vapor can pass through the filter membrane, but the liquid cannot pass through the filter membrane. The lower part of the evaporating chamber 2 and the condensing chamber 19 is provided with a gas circulating fan 8. The cross-sectional area of the lower part of the evaporating chamber 2 and the condensing chamber 19 is gradually reduced from the condensing chamber 19 to the evaporating chamber 2, and the side of the condensing chamber 19 is provided with air At the inlet, the air inlet surface of the gas circulation fan 8 faces the air inlet, and the air outlet surface faces the evaporation chamber 2.

The inlet of the evaporation chamber 2 is connected with a concentrated brine feed pump 1. The evaporation chamber 2 is equipped with an evaporation chamber sprayer 9 and an evaporation chamber filler 10. The evaporation chamber sprayer 9 is set above the evaporation chamber filler 10, and the evaporation chamber sprayer 9 can be set up in multiple layers, the bottom outlet of the evaporation chamber 2 is connected with the crystallization kettle 4, and the connection pipe between the bottom outlet of the evaporation chamber 2 and the crystallization kettle 4 is equipped with a concentrated brine discharge pump 3; the crystallization kettle 4 and a concentrated brine feed pump 1 Connection, the bottom side outlet of the evaporation chamber 2 is connected with the hot side of the evaporative condensation heat exchanger 6, and the connecting pipeline between the bottom side outlet of the evaporation chamber 2 and the hot side of the evaporative condensation heat exchanger 6 is equipped with a concentrated brine internal circulation pump 5. The hot side of the evaporative-condensation heat exchanger 6 is connected to the evaporation chamber sprayer 9, and a waste heat utilization heat exchanger can be installed on the connecting pipeline between the hot side of the evaporative-condensation heat exchanger 6 and the evaporation chamber sprayer 9 7. The waste heat utilization heat exchanger 7 is connected with the external system, and the waste heat of the external system is introduced into the system.

The condensing chamber 19 is provided with a condensing chamber sprinkler 17 and a condensing chamber filler 18. The condensing chamber sprinkler 17 is arranged above the condensing chamber filler 18. The condensing chamber sprinkler 17 can be arranged in multiple layers, and the refrigeration chamber units include sequentially connected The hot end heat exchanger 12 of the refrigeration chamber, the throttle valve 13, the cold end heat exchanger 14 of the refrigeration chamber and the refrigeration chamber compressor 15, the low boiling point working fluid is in the hot end heat exchanger 12, the throttle valve 13, and the refrigeration chamber The cold end heat exchanger 14 and the refrigerating chamber compressor 15 circulate, the bottom outlet of the condensing chamber 19 is connected to the hot end heat exchanger 12 of the refrigerating chamber, and the connecting pipe between the bottom outlet of the condensing chamber 19 and the hot end heat exchanger 12 of the refrigerating chamber There is a condensate internal circulation pump 11 on the road, the hot end heat exchanger 12 of the refrigeration chamber is connected to the cold side of the evaporative condensation heat exchanger 6; the condensing device 16 is connected to the cold end heat exchanger 14 of the refrigeration chamber, and the cold end of the refrigeration chamber exchanges heat The condenser 14 is connected to the condensing chamber sprayer 17; the cold side of the evaporative condensing heat exchanger 6 is connected to a condensing device 16. The condensing device 16 can be a condensing fan or a cooler, and the condensing device 16 is connected to the cold end of the refrigerating chamber unit, and the refrigerating chamber The cold end of the unit is connected with the condensing chamber sprayer 17; the bottom side outlet of the condensing chamber 19 is connected with a condensate discharge pipe, and the condensate drain pump 20 is provided on the condensate discharge pipe.

The working method of the above-mentioned energy-saving zero-emission low-temperature atmospheric pressure evaporative crystallization system includes:

The concentrated brine enters the evaporation chamber 2 through the concentrated brine feed pump 1, and the concentrated liquid at the bottom of the evaporation chamber 2 enters the hot side of the evaporative condensation heat exchanger 6 through the concentrated brine internal circulation pump 5, and the temperature of the cold side of the evaporative condensation heat exchanger 6 The higher condensate heat exchanges into high-temperature concentrated liquid, and then the waste heat uses the heat exchanger 7 to absorb the heat to continue to increase the temperature, sprayed from the evaporation chamber sprayer 9, and sent from the gas circulation fan 8 in the area of the evaporation chamber filling 10 The incoming air will return to the bottom of the evaporation chamber 2 after reverse contact with the temperature. During the contact process, the moisture in the concentrated liquid is absorbed by the heated air, while the salt is retained in the concentrated liquid; the concentrated liquid at the bottom of the evaporation chamber 2 will continue to accumulate salinity and gradually Close to the crystallization saturation concentration; the bottom concentrated liquid enters the crystallization tank 4 from the bottom outlet of the evaporation chamber 2 through the concentrated brine discharge pump 3 to achieve solid-liquid separation to obtain solid salt, and the turbid liquid of the crystallization tank 4 returns to the concentrated brine feed pump 1 and then circulates;

The hot air with moisture enters the condensing chamber 19 through the air inlet, and the spray liquid of the condensing chamber sprayer 17 is in contact with the condensing chamber filler 18 in the same direction to cool down. During the cooling process, the moisture in the air condenses into condensate and falls; after the air cools down Then it is sent to the evaporation chamber 2 by the gas circulation fan 8; the condensate accumulates at the bottom of the condensing chamber 19, from the bottom outlet of the condensing chamber 19 through the condensate internal circulation pump 11, the refrigerating chamber hot end heat exchanger 12, and the refrigerated chamber compressor 15 The low-boiling-point working fluid (commonly used refrigerants can be selected for compression work) heats up to increase the temperature, the heated condensate exchanges heat with the concentrated liquid in the evaporative condensation heat exchanger 6 and then cools down, and the cooled condensate passes through the condensing device 16 Further reduce the temperature, and then exchange heat in the cold end of the refrigeration chamber unit to cool down again, and then the low-temperature condensate enters the condensing chamber sprayer 17; the accumulated condensate is used as the system output water and is discharged from the condensate through the condensate drain pump 20 Pipe delivery system;

The air enters the condensing chamber 19 from the air inlet under the suction force of the gas circulation fan 8 to maintain the slightly positive pressure of the system, and circulates in the annular gas circulation channel formed by the evaporation chamber 2 and the condensing chamber 19.

It should be noted that the above description is only a part of the embodiments of the present invention, and equivalent changes made according to the system described in the present invention are all included in the protection scope of the present invention. Those skilled in the art to which the present invention pertains can make similar substitutions to the specific examples described, as long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, it belongs to the protection scope of the present invention.

Claims

An energy-saving zero-discharge low-temperature atmospheric evaporative crystallization system, which is characterized by comprising an evaporation chamber (2), a crystallization kettle (4), an evaporative condensation heat exchanger (6), a condensation chamber (19) and a refrigeration chamber unit;

The top and bottom of the evaporation chamber (2) and the condensation chamber (19) are connected to form a ring-shaped gas circulation channel. The top of the evaporation chamber (2) and the condensation chamber (19) is connected with an insulating barrier, and the evaporation chamber (2) A gas circulating fan (8) is provided at the lower part of the condensing chamber (19). The side of the condensing chamber (19) is provided with an air inlet. The air inlet surface of the gas circulating fan (8) faces the air inlet and the air outlet surface faces the evaporation. Room(2);

The inlet of the evaporation chamber (2) is connected with a concentrated brine feed pump (1), the evaporation chamber (2) is equipped with an evaporation chamber sprayer (9) and an evaporation chamber filler (10), and the evaporation chamber sprayer (9) is provided with Above the filling (10) of the evaporation chamber, the bottom outlet of the evaporation chamber (2) is connected with the crystallization kettle (4), the crystallization kettle (4) is connected with the brine feed pump (1), and the bottom side outlet of the evaporation chamber (2) is connected with the evaporation chamber (2). The hot side of the condensation heat exchanger (6) is connected, and the hot side of the evaporative condensation heat exchanger (6) is connected with the evaporation chamber sprayer (9);

The condensing chamber (19) is provided with a condensing chamber sprayer (17) and a condensing chamber filler (18). The condensing chamber sprayer (17) is set above the condensing chamber filler (18), and the bottom outlet of the condensing chamber (19) is connected to The hot end of the refrigeration room unit is connected, the hot end of the refrigeration room unit is connected to the cold side of the evaporative condensation heat exchanger (6), and the cold side of the evaporative condensation heat exchanger (6) is connected with a condensing device (16) and a condensing device (16) It is connected with the cold end of the refrigeration chamber unit, and the cold end of the refrigeration chamber unit is connected with the condensing chamber sprayer (17); the bottom side outlet of the condensing chamber (19) is connected with a condensate discharge pipe.
The energy-saving zero-emission low-temperature atmospheric evaporative crystallization system according to claim 1, wherein the refrigeration chamber unit includes a refrigeration chamber hot end heat exchanger (12), a throttle valve (13), and a refrigeration chamber cold end connected in sequence. The heat exchanger (14) and the refrigeration chamber compressor (15), the low-boiling point working medium is in the refrigeration chamber hot end heat exchanger (12), throttle valve (13), refrigeration chamber cold end heat exchanger (14) and refrigeration Circulates in the chamber compressor (15), the outlet at the bottom of the condensing chamber (19) is connected to the hot end heat exchanger (12) of the refrigeration chamber. Side connection; the condensing device (16) is connected with the cold end heat exchanger (14) of the refrigeration chamber, and the cold end heat exchanger (14) of the refrigeration chamber is connected with the condensing chamber sprayer (17).
The energy-saving zero-discharge low-temperature atmospheric evaporative crystallization system according to claim 1, wherein the condensing device (16) is a condensing fan or a cooler.
The energy-saving zero-discharge low-temperature atmospheric evaporative crystallization system according to claim 1, characterized in that the connection pipeline between the bottom outlet of the evaporation chamber (2) and the crystallization kettle (4) is provided with a concentrated brine discharge pump (3) .
The energy-saving zero-discharge low-temperature atmospheric evaporative crystallization system according to claim 1, characterized in that the connecting pipeline between the bottom side outlet of the evaporation chamber (2) and the hot side of the evaporative condensation heat exchanger (6) is provided with a concentration Brine internal circulation pump (5).
The energy-saving zero-discharge low-temperature atmospheric evaporative crystallization system according to claim 1, characterized in that the connecting pipeline between the bottom outlet of the condensing chamber (19) and the hot end of the refrigerating chamber unit is provided with a condensate internal circulation pump (11) .
The energy-saving zero-discharge low-temperature atmospheric evaporative crystallization system according to claim 1, characterized in that the condensate discharge pipe is provided with a condensate discharge pump (20).
The energy-saving zero-discharge low-temperature atmospheric evaporative crystallization system according to claim 1, characterized in that the connecting pipeline between the hot side of the evaporative-condensation heat exchanger (6) and the evaporation chamber sprayer (9) is provided with waste heat The heat exchanger (7) is used, and the waste heat is connected with the external system by the heat exchanger (7).
The energy-saving zero-emission low-temperature atmospheric pressure evaporative crystallization system according to claim 1, wherein the evaporation chamber sprayer (9) and the condensation chamber sprayer (17) are both multilayered.
The working method of the energy-saving zero-emission low-temperature atmospheric evaporative crystallization system according to any one of claims 1-9, characterized in that it comprises:

The concentrated brine enters the evaporation chamber (2) through the concentrated brine feed pump (1), and the concentrated liquid at the bottom of the evaporation chamber (2) enters the hot side of the evaporative condensation heat exchanger (6), and is connected to the evaporative condensation heat exchanger (6). The condensate with higher temperature on the cold side exchanges heat into a high-temperature concentrated liquid, which is sprayed from the evaporation chamber sprayer (9), and in the area of the evaporation chamber filler (10), it contacts with the air sent from the gas circulation fan (8) in reverse to cool down After returning to the bottom of the evaporation chamber (2), the moisture in the concentrated liquid is absorbed by the heated air during the contact process, while the salt is retained in the concentrated liquid; the concentrated liquid at the bottom of the evaporation chamber (2) will continue to accumulate salinity and gradually approach crystallization Saturated concentration; the bottom concentrated liquid enters the crystallization kettle (4) from the bottom outlet of the evaporation chamber (2) to achieve solid-liquid separation to obtain solid salt, and the turbid liquid of the crystallization kettle (4) returns to the concentrated brine feed pump (1) and then circulates;

The hot air with moisture enters the condensing chamber (19) through the air inlet, and the spray liquid of the condensing chamber sprayer (17) is in contact with the condensing chamber filler (18) in the same direction to cool down. During the cooling process, the moisture in the air condenses into condensation The liquid falls; the air is cooled down and then sent to the evaporation chamber (2) by the gas circulation fan (8); the condensate accumulates at the bottom of the condensing chamber (19) and enters the hot end of the refrigeration chamber from the bottom outlet of the condensing chamber (19) to exchange heat and increase the temperature , The warmed condensate exchanges heat with the concentrated liquid in the evaporative condensation heat exchanger (6) and then cools down. The cooled condensate passes through the condensing device (16) to further reduce the temperature, and then exchanges heat again in the cold end of the refrigeration chamber unit Cool down, and then the low-temperature condensate enters the condensing chamber sprayer (17); the accumulated condensate is sent out of the system through the condensate discharge pipe as the system output water;

The air enters the condensation chamber (19) from the air inlet under the suction force of the gas circulation fan (8) to maintain the slightly positive pressure of the system. The annular gas circulation channel formed in the evaporation chamber (2) and the condensation chamber (19) In the loop.