Normal pressure low temperature evaporation crystallization device and separation method of industrial waste brine

Abstract

The application discloses a normal-pressure low-temperature evaporation crystallization device and a separation method of industrial waste brine, and relates to the technical field of evaporation crystallization. The heat exchange efficiency of raw material liquid in the falling film tube is improved by arranging the spiral liquid inlet channel. The raw material liquid after being heated enters the packing layer of the humidification tower, so that the contact area of the raw material liquid and the gas in the humidification tower is increased, the evaporation efficiency of the solvent in the raw material liquid is improved, and the crystallization process of the raw material liquid after entering the evaporation crystallizer is facilitated. The gas with high temperature in the tower carries the solvent in the raw material liquid to enter the dehumidification tower through the first gas outlet, the liquid content carried in the gas is reduced, and then the gas is returned to the humidification tower for recycling. The device can operate under normal pressure, has low operation condition requirement, high economic benefit, realizes non-boiling evaporation of the solvent in the humidification tower by matching the integrated structure of the humidification tower, reduces the operation temperature, significantly improves the resource utilization rate, and meets the development requirement of clean production and circular economy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of evaporation crystallization, in particular to a normal-pressure low-temperature evaporation crystallization device and a separation method of industrial waste brine. BACKGROUND

[0002] In the production process of chemical materials, a large amount of washing wastewater is easily generated, and the washing wastewater contains a high salt content, such as sodium chloride and sodium sulfate. The washing wastewater needs to be treated and the salt content needs to be removed before it can be discharged, so how to recover and treat the salt content in the salt-containing washing wastewater is the key to ensuring the sustainable production of chemical materials.

[0003] At present, the treatment method for salt-containing washing wastewater is generally to separate the solid salt in the salt-containing washing wastewater from water by evaporation crystallization. However, the traditional treatment method uses a high-temperature and / or high-pressure evaporation crystallization device and process, such as an MVR evaporator, which consumes a large amount of heat source and has high energy consumption. At the same time, evaporation crystallization at high temperature not only has requirements for the salt-containing washing wastewater to be treated, but also can only treat salt-containing washing wastewater that is not sensitive to temperature. The structure of salt that is sensitive to temperature will be destroyed at high temperature, making it difficult to recycle. Moreover, the material of the equipment also has requirements, and the material of the equipment needs to be a high-temperature resistant material. Even some processes use a vacuum evaporation crystallization device to treat salt-containing washing wastewater, which seriously increases the investment cost of the equipment. Since the salt-containing washing wastewater is not the target product of the production of chemical materials, if the cost of environmental protection aftertreatment is high, it will limit the production process of chemical materials.

[0004] In view of this, the present application is proposed. SUMMARY

[0005] The purpose of the present application is to provide a normal-pressure low-temperature evaporation crystallization device and a separation method of industrial waste brine.

[0006] The present application is implemented as follows:

[0007] In a first aspect, the present application provides a normal-pressure low-temperature evaporation crystallization device, which comprises a raw material liquid storage tank, a humidification tower, a dehumidification unit and a separation unit.

[0008] The humidification tower comprises a falling film tube part, a humidification tower filler layer and an evaporation crystallizer arranged in sequence from top to bottom and integrated into one body. The humidification tower is provided with a first raw material liquid inlet on the side close to the falling film tube part. The first raw material liquid inlet is in communication with the raw material liquid storage tank through a pipeline.

[0009] The falling film tube part comprises a falling film tube liquid distributor and a falling film tube body, the falling film tube body comprises a first heat exchange channel and a second heat exchange channel, the falling film tube liquid distributor comprises a liquid distribution pipe, one end of the liquid distribution pipe is provided with a spiral liquid inlet channel, and the falling film tube liquid distributor is in communication with the first heat exchange channel through the spiral liquid inlet channel.

[0010] The dehumidification unit comprises a dehumidification tower, the dehumidification tower comprises a second gas inlet and a second gas outlet; the humidification tower is further provided with a first gas inlet on one side close to the falling film tube part, the evaporative crystallizer is provided with a first gas outlet on one side close to the humidification tower filler layer, the first gas outlet and the second gas inlet are in communication, and the second gas outlet and the first gas inlet are in communication, so that the humidification tower and the dehumidification tower are in communication.

[0011] The evaporative crystallizer is provided with a salt liquid outlet on one side away from the first gas outlet, the salt liquid outlet is in communication with the separation unit through a pipeline, and the liquid obtained by separation of the separation unit is returned to the humidification tower.

[0012] In an optional embodiment, the evaporative crystallizer comprises an evaporation zone, a mixing zone and a crystallization zone in sequence, the evaporation zone is in communication with the humidification tower filler layer, the crystallization zone is provided with a crystal growth device, and an opening at the bottom of the crystallization zone is the salt liquid outlet.

[0013] And / or, the shape of the shell of the mixing zone is a conical shape, the crystal growth device is a V-shaped crystal growth device, the edge of the V-shaped crystal growth device is arranged in a spaced manner with the wall surface of the crystallization zone, the crystallization zone is further provided with a second raw material liquid inlet, the second raw material liquid inlet is located above the V-shaped crystal growth device, and the second raw material liquid inlet is in communication with the raw material liquid storage tank through a pipeline.

[0014] And / or, the V-shaped angle of the V-shaped crystal growth device is 120-165°.

[0015] And / or, a visual window is further arranged on the crystallization zone, and the visual window is located above the crystal growth device.

[0016] And / or, the evaporative crystallizer is further provided with a clear liquid outlet, the clear liquid outlet is located between the salt liquid outlet and the first gas outlet, and the clear liquid outlet is in communication with the first raw material liquid inlet of the humidification tower through a pipeline.

[0017] In an optional embodiment, a gas opening adjusting assembly is arranged at the first gas outlet, and the gas opening adjusting assembly comprises any one of a louver adjusting assembly or a positioning pin.

[0018] And / or, the louver adjusting assembly comprises a fixed part, a plurality of openings are formed in the fixed part, a regulating part is arranged on the surface of each opening, and the regulating part is selectively movable relative to the fixed part to open or close the opening.

[0019] And / or, the number of openings on the fixed part is at least two.

[0020] And / or, the first gas outlet is further provided with a humidifying tower demister, and the humidifying tower demister is located below the gas opening adjusting assembly.

[0021] And / or, the humidifying tower demister comprises any one of a wire mesh demister or a spray head.

[0022] In an optional embodiment, the falling film pipe liquid distributor further comprises a liquid distribution pipe support fixed in the humidifying tower, a liquid distribution pipe fixedly connected with the liquid distribution pipe support, and a first inlet of the spiral liquid inlet channel is arranged at the connection position, and the end of the liquid distribution pipe away from the spiral liquid inlet channel is sealed by a liquid distribution pipe cap.

[0023] And / or, the inner diameter of the first heat exchange channel is greater than the outer diameter of the liquid distribution pipe, so that the spiral liquid inlet channel is located in the first heat exchange channel.

[0024] And / or, the end of the liquid distribution pipe with the spiral liquid inlet channel is a flared opening.

[0025] And / or, the inner wall surface of the spiral liquid inlet channel is provided with a hydrophilic wear-resistant coating.

[0026] And / or, the hydrophilic wear-resistant coating comprises any one of a carbon nanotube-ceramic composite coating or a silicon carbide coating.

[0027] In an optional embodiment, the humidifying tower is further provided with an ultrasonic generator, and the ultrasonic generator is arranged corresponding to the falling film pipe portion.

[0028] And / or, the ultrasonic generator is located on the outer surface of the humidifying tower.

[0029] And / or, the atmospheric low-temperature evaporation crystallization device further comprises a plurality of detectors, and the detectors comprise at least one of a pressure detector, a temperature detector, a flow detector, and a wind speed detector.

[0030] In an optional embodiment, the humidifying tower is further provided with a humidifying tower spray head, and the humidifying tower spray head is located above the falling film pipe portion and is in communication with the first raw material liquid inlet through a pipeline.

[0031] And / or, the first gas inlet is located at the top of the humidifying tower, and the humidifying tower is further provided with a gas distributor, and the gas distributor is located below the first gas inlet.

[0032] In an optional embodiment, the dehumidification unit further comprises a heat exchanger, and the dehumidification tower is in communication with the heat exchanger through a pipeline to cool the gas in the dehumidification tower.

[0033] And / or, the dehumidification tower is provided with a dehumidification tower packing layer, and a dehumidification tower spray head is arranged above the dehumidification tower packing layer, the dehumidification tower spray head is communicated with the outlet of the heat exchanger through a pipeline, and the dehumidification tower is also provided with a solution outlet, which is communicated with the inlet of the heat exchanger.

[0034] And / or, the number of the dehumidification tower packing layers is multiple, a dehumidification tower spray head is arranged above each dehumidification tower packing layer, and each dehumidification tower spray head is communicated with the outlet of the heat exchanger through a pipeline.

[0035] And / or, the dehumidification unit further comprises a solution buffer tank, the inlet of the solution buffer tank is communicated with the solution outlet, and the outlet of the solution buffer tank is communicated with the inlet of the heat exchanger.

[0036] And / or, a solution circulating pump is further arranged on the pipeline, wherein the outlet of the solution buffer tank is communicated with the inlet of the heat exchanger.

[0037] And / or, the outlet of the solution buffer tank is further communicated with an external liquid pipeline.

[0038] And / or, an induced draft fan is arranged on the pipeline, wherein the first gas outlet is communicated with the second gas inlet, and / or the second gas outlet is communicated with the first gas inlet.

[0039] In an optional embodiment, the separation unit comprises at least one of a cyclone, a thickener and a centrifuge.

[0040] And / or, the separation unit comprises a cyclone, a thickener and a centrifuge, the inlet of the cyclone is communicated with the brine outlet of the humidification tower through a pipeline, the solid outlet of the cyclone is communicated with the inlet of the thickener, the solid outlet of the thickener is communicated with the inlet of the centrifuge, and the cyclone, the thickener and the centrifuge are all provided with a liquid outlet, which is communicated with the first raw liquid inlet of the humidification tower.

[0041] And / or, the separation unit further comprises a liquid storage tank, the liquid outlets are all communicated with the liquid storage tank through pipelines, and the liquid storage tank is further communicated with the first raw liquid inlet through a pipeline.

[0042] And / or, a liquid delivery pump is further arranged on the pipeline, wherein the liquid storage tank is communicated with the first raw liquid inlet.

[0043] And / or, a humidification tower discharge pump is arranged on the pipeline, wherein the cyclone is communicated with the brine outlet.

[0044] In a second aspect, the present application provides a separation method of industrial waste brine, which is suitable for the atmospheric low-temperature evaporation crystallization device according to any one of the foregoing embodiments, and the method comprises the following steps: introducing a raw liquid into the humidification tower, the raw liquid is uniformly distributed through the falling film tube liquid distributor, and is rotated into the first heat exchange channel of the falling film tube body through the spiral liquid inlet channel, and is heated after heat exchange with the heat medium in the first heat exchange channel and the second heat exchange channel.

[0045] The heated raw material liquid passes through the packing layer of the humidification tower and enters the evaporative crystallizer. The heated raw material liquid crystallizes in the evaporative crystallizer. The crystals obtained by crystallization and the liquid in the evaporative crystallizer enter the separation unit for solid-liquid separation. The liquid separated by the separation unit is returned to the humidification tower for recycling.

[0046] The heated raw material liquid increases the temperature of the gas in the evaporative crystallizer, so that the water content of the gas in the evaporative crystallizer increases. The gas from the first gas outlet of the evaporative crystallizer flows into the dehumidification tower to remove water, and then returns to the humidification tower for recycling.

[0047] The raw material liquid to be treated is in counterflow contact with the gas in the humidification tower.

[0048] In an optional embodiment, the method for removing water in the dehumidification tower is to cool the gas from the evaporative crystallizer.

[0049] And / or, the solid-liquid separation method of the separation unit includes at least one of centrifugation, sedimentation and filtration.

[0050] The present application has the following beneficial effects:

[0051] The application provides a normal-pressure low-temperature evaporation crystallization device and a separation method of industrial waste brine. The device can be operated under normal pressure, air in the device is used as carrier gas, air in the humidification tower carries the solvent in the raw material liquid, then the solvent is removed in the dehumidification tower, and the air returns to the humidification tower for recycling, the operation condition requirement is low, the device has high economic benefits for recovery and treatment of salt-containing washing wastewater. BRIEF DESCRIPTION OF DRAWINGS

[0052] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments, and it should be understood that the following drawings only show some of the embodiments of the application, and should not be regarded as a limitation to the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor.

[0053] Figure 1 The structural schematic diagram of the normal-pressure low-temperature evaporation crystallization device provided by the embodiments of the application;

[0054] Figure 2 The structural schematic diagram of the humidification tower provided by the embodiments of the application;

[0055] Figure 3 The structural schematic diagram of the falling film tube part provided by the embodiments of the application;

[0056] Figure 4 Structure diagram of falling film tube liquid distributor provided for the embodiment of the present application Figure 1 ;

[0057] Figure 5 Structure diagram of evaporative crystallizer provided for the embodiment of the present application

[0058] Figure 6 Upper structure diagram of evaporative crystallizer provided for the embodiment of the present application

[0059] Figure 7 Structure diagram of louvered adjusting assembly provided for the embodiment of the present application

[0060] Figure 8 Structure diagram of dehumidification tower provided for the embodiment of the present application

[0061] Figure 9 Operating principle diagram of atmospheric low-temperature evaporative crystallization device provided for the embodiment of the present application

[0062] Main element symbol explanation: 10-atmospheric low-temperature evaporative crystallization device; 100-raw material liquid storage tank; 200-humidification tower; 210-falling film tube part; 211-falling film tube liquid distributor; 2111-liquid distribution pipe; 2112-spiral liquid inlet channel; 2113-liquid distribution pipe support; 2114-liquid distribution pipe cap; 2115-first inlet; 212-falling film tube body; 2121-first heat exchange channel; 2122-second heat exchange channel outlet; 2123-second heat exchange channel inlet; 220-humidification tower filler layer; 230-evaporative crystallizer; 231-salt liquid outlet; 232-evaporation zone; 233-mixing zone; 234-crystallization zone; 241-first raw material liquid inlet; 242-first gas inlet; 243-first gas outlet; 244-second raw material liquid inlet; 245-clear liquid outlet; 250-louvered adjusting assembly; 251-fixing part; 252-adjusting part; 260-humidification tower demister; 270-ultrasonic generator; 280-humidification tower spray head; 290-gas distributor; 300-dehumidification unit; 310-dehumidification tower; 311-second gas inlet; 312-second gas outlet; 313-dehumidification tower filler layer; 314-dehumidification tower spray head; 315-solution outlet; 316-dehumidification tower demister; 320-heat exchanger; 330-solution buffer tank; 340-solution circulating pump; 400-separation unit; 410-cyclone; 420-thickener; 430-centrifuge; 450-liquid storage tank; 460-liquid delivery pump; 500-inducing fan; 600-humidification tower discharge pump; 700-V-shaped crystal growth device; 710-V-shaped crystal growth device support; 800-solid salt storage tank; 20-external liquid pipeline. DETAILED DESCRIPTION

[0063] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the accompanying drawings for the embodiments of the present application will be briefly described, and the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are some but not all of the embodiments of the present application. Generally, the components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0064] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents the selected embodiments of the application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0065] It should be noted that: similar reference numerals and letters indicate similar items in the following drawings, and therefore, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

[0066] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present application is usually placed, and are merely for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0067] In addition, the terms "horizontal", "vertical" and the like do not mean that the components must be absolutely horizontal or vertical, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0068] In the description of the present application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0069] Firstly, please refer toFigure 1 The embodiment provides a normal-pressure low-temperature evaporation crystallization device 10, which comprises a raw material liquid storage tank 100, a humidification tower 200, a dehumidification unit 300 and a separation unit 400.

[0070] Please refer to Figure 2 The humidification tower 200 comprises a falling film tube part 210, a humidification tower filler layer 220 and an evaporation crystallizer 230 arranged in sequence from top to bottom and integrated into one body, a first raw material liquid inlet 241 is arranged on the side close to the falling film tube part 210 of the humidification tower 200, i.e. the upper part of the humidification tower 200, and the first raw material liquid inlet 241 is in communication with the raw material liquid storage tank 100 through a pipeline.

[0071] Please refer to Figure 3 The falling film tube part 210 comprises a falling film tube body 212, the falling film tube body 212 comprises a first heat exchange channel 2121 and a second heat exchange channel, the first heat exchange channel 2121 and the second heat exchange channel are heat-exchanged through an interwall, the first heat exchange channel 2121 is used for flowing the raw material liquid to be treated, and the second heat exchange channel is in communication with an external heat medium source, so that the raw material liquid to be treated is heated after passing through the falling film tube body 212.

[0072] Since the normal-pressure low-temperature evaporation crystallization device 10 provided by the embodiment realizes the evaporation crystallization process under the normal-pressure and low-temperature state in the non-boiling evaporation mode, compared with the traditional high-temperature evaporation, the external heat medium source connected with the falling film tube body 212 in the embodiment is not limited to the high-temperature steam specially prepared, but can directly utilize the residual heat source in other process flows, such as the low-quality heat source of secondary steam, steam condensate and exhaust steam generated in the rectification process, so that the heat utilization rate is improved, the heating process of the raw material liquid to be treated does not need to consume additional cost, and excellent economic benefits are obtained.

[0073] Preferably, the external heat medium source connected with the falling film tube body 212 is the residual heat source in other process flows.

[0074] Preferably, the surface area of the falling film tube body 212 can be 8-12 m 2 .

[0075] In order to ensure the uniform distribution of the raw material liquid to be treated in the falling film tube and ensure the heating effect of the raw material liquid to be treated, the falling film tube part 210 further comprises a falling film tube liquid distributor 211.

[0076] In the embodiments as shown in Figure 3 and Figure 4 , in order to ensure the installation stability of the falling film tube part 210, the falling film tube liquid distributor 211 further comprises a liquid distribution pipe support 2113, the liquid distribution pipe support 2113 is fixed to the inner wall surface of the humidification tower 200, and the thickness of the liquid distribution pipe support 2113 is 14-18 mm.

[0077] The falling film pipe liquid distributor 211 comprises a liquid distribution pipe 2111, one end of the liquid distribution pipe 2111 is provided with a spiral liquid inlet channel 2112, and the falling film pipe liquid distributor 211 is in communication with the first heat exchange channel 2121 through the spiral liquid inlet channel 2112. By arranging the spiral liquid inlet channel 2112, the raw material liquid to be treated is spirally introduced into the first heat exchange channel 2121 of the falling film pipe, the path of the raw material liquid flowing in the falling film pipe is increased, and the degree of flow disturbance of the raw material liquid is also increased by the impact of the inner wall surface of the first heat exchange channel 2121 during the spiral process of the raw material liquid in the first heat exchange channel 2121, thereby improving the heat exchange efficiency of the raw material liquid in the falling film pipe.

[0078] The liquid distribution pipe 2111 is fixedly connected with the liquid distribution pipe support 2113, and the first inlet 2115 of the spiral liquid inlet channel 2112 is arranged at the connection position.

[0079] The liquid distribution pipe support 2113 and the inner wall surface of the humidification tower 200 can be connected by welding, bolt connection or other connection modes, and the plurality of liquid distribution pipes 2111 can also be welded on the liquid distribution pipe support 2113, as long as the first inlet 2115 of the spiral liquid inlet channel 2112 is not blocked.

[0080] The number of the liquid distribution pipes 2111 is multiple, and the number of the corresponding first heat exchange channels 2121 is also multiple. The plurality of liquid distribution pipes 2111 and the plurality of first heat exchange channels 2121 are arranged one by one. The plurality of liquid distribution pipes 2111 are uniformly and interval arranged on the liquid distribution pipe support 2113. In order to ensure good mass transfer effect, avoid insufficient mass transfer caused by too few liquid distribution pipes 2111, and reduce the cost and evaporation efficiency caused by too many liquid distribution pipes 2111, the number of the liquid distribution pipes 2111 is preferably in the range of 60-80.

[0081] Further, in order to ensure that the raw material liquid to be treated enters the falling film pipe from the first inlet 2115, the falling film pipe liquid distributor 211 further comprises a liquid distribution pipe cap 2114, and the end of the liquid distribution pipe 2111 away from the spiral liquid inlet channel 2112 is sealed by the liquid distribution pipe cap 2114.

[0082] In the preferred embodiment, the spiral liquid inlet channel 2112 is located on the outer surface of the liquid distribution pipe 2111, and the inner diameter of the first heat exchange channel 2121 is larger than the outer diameter of the liquid distribution pipe 2111, so that the spiral liquid inlet channel 2112 is located inside the first heat exchange channel 2121. When the raw material liquid to be treated enters the first heat exchange channel 2121 through the first inlet 2115, most of the raw material liquid will enter in a spiral manner inside the spiral liquid inlet channel 2112, and a small part of the raw material liquid will be thrown out of the spiral liquid inlet channel 2112 due to excessive centrifugal force, contact the inner wall of the first heat exchange channel 2121 and rebound, increasing the turbulence of the raw material liquid, reducing the dynamic viscosity of the raw material liquid, facilitating the diffusion of solvent molecules in the raw material liquid to the gas, increasing the possibility of capturing solvent by the gas in the humidification tower 200, and facilitating the subsequent crystallization process.

[0083] In a further preferred embodiment, the liquid distribution pipe 2111 has a trumpet-shaped end of the spiral liquid inlet channel 2112, which improves the rotational power of the raw material liquid in the first heat exchange channel 2121 and improves the heat exchange capacity of the raw material liquid and the heat medium in the second heat exchange channel.

[0084] In the preferred embodiment, since the raw material liquid to be treated is mostly a salt solution, in order to avoid crystallization of a small part of the salt in the falling film tube part 210 during the evaporation crystallization process, thereby blocking the spiral liquid inlet channel 2112, a hydrophilic wear-resistant coating is provided on the inner wall of the spiral liquid inlet channel 2112, such as any one of a carbon nanotube-ceramic composite coating or a silicon carbide coating.

[0085] Please refer to Figure 2 , further, an ultrasonic generator 270 can be further provided on the humidification tower 200, and the ultrasonic generator 270 is correspondingly provided with the falling film tube part 210. The ultrasonic generator 270 not only serves as an effective enhancement measure to promote the evaporation of the raw material liquid to be treated, but also reduces the dynamic viscosity of the raw material liquid, which is beneficial to the diffusion of the solvent to the gas; at the same time, it can also improve the cavitation effect of the raw material liquid to be treated in the falling film tube body 212, greatly increasing the anti-fouling effect.

[0086] Through the joint setting of the ultrasonic generator 270 and the hydrophilic wear-resistant coating, the fouling of the falling film tube part 210, especially the spiral liquid inlet channel 2112, can be greatly avoided. Through the design of the ultrasonic generator 270 and the spiral liquid inlet channel 2112 located inside the first heat exchange channel 2121, and the trumpet-shaped end of the liquid distribution pipe 2111 having the spiral liquid inlet channel 2112, the dynamic viscosity of the raw material liquid can be greatly reduced, which is beneficial to the diffusion of the solvent to the gas, and thus is beneficial to the formation of the subsequent crystallization.

[0087] In the preferred embodiment, the ultrasonic generator 270 is located on the outer surface of the humidification tower 200.

[0088] In a preferred embodiment, the unit power of the ultrasonic generator 270 is 20-50 w / m 2 , and the frequency is 20-40 Hz.

[0089] In a preferred embodiment, in order to ensure the uniform distribution of the raw material liquid to be treated in the falling film tube part 210, a humidification tower spray head 280 is further arranged in the humidification tower 200, which is located above the falling film tube part 210 and is in communication with the first raw material liquid inlet 241 through a pipeline.

[0090] The raw material liquid to be treated is heated in the falling film tube part 210, so the temperature of the gas (such as air) in the humidification tower 200 is also increased, the water carrying capacity of the gas is improved, and the structure design of the falling film tube part 210 makes the solvent in the raw material liquid to be treated transfer to the gas, and the water content in the heated raw material liquid is reduced, which is beneficial to the subsequent crystallization.

[0091] The raw material liquid with high temperature enters the humidification tower packing layer 220, the volume of the humidification tower packing layer 220 is 0.1-0.3 m 3 , and the specific surface area is 120-180 m 2 / m 3 . The humidification tower packing layer 220 can be filled with regular corrugated packing, and the material can be any one of PP, PVC or ceramic.

[0092] The humidification tower packing layer 220 is located between the falling film tube part 210 and the evaporative crystallizer 230, by arranging the humidification tower packing layer 220, the heated raw material liquid is distributed in the humidification tower packing layer 220, the gas-liquid contact area is increased, and the ability of the solvent in the raw material liquid to transfer to the gas is further improved.

[0093] The raw material liquid passing through the humidification tower packing layer 220 enters the evaporative crystallizer 230 below it for crystallization.

[0094] Please refer to Figure 2 , the evaporative crystallizer 230 includes an evaporation zone 232, a mixing zone 233 and a crystallization zone 234 which are sequentially communicated, the evaporation zone 232 is in communication with the humidification tower packing layer 220, and a crystal growth device is arranged in the crystallization zone 234, and the opening at the bottom of the crystallization zone 234 is a salt liquid outlet 231.

[0095] The raw material liquid passing through the packing layer 220 of the humidification tower is accumulated in the evaporative crystallizer 230, and the solid solute is crystallized and separated. The separated crystals collide with each other in the evaporative crystallizer 230, grow, and then sink into the crystallization zone 234. The crystals of sufficient size are screened at the crystal growth device in the crystallization zone 234, and then flow out from the salt liquid outlet 231 at the bottom of the crystallization zone 234. The salt liquid outlet 231 is connected to the separation unit 400 through a pipeline, and the obtained liquid is returned to the humidification tower 200 for repeated use to improve the desalination capacity of the raw material liquid.

[0096] Please refer to Figure 5 In the preferred embodiment, the outer shell of the mixing zone 233 is in the shape of a cone, and the crystal growth device is a V-shaped crystal growth device 700. The V-shaped crystal growth device 700 is fixed in the crystallization zone by a V-shaped crystal growth device support 710, and the edge of the V-shaped crystal growth device 700 is spaced apart from the wall surface of the crystallization zone 234. The crystallization zone 234 is also provided with a second raw material liquid inlet 244, which is located above the V-shaped crystal growth device 700 and is connected to the raw material liquid storage tank 100 through a pipeline.

[0097] By setting the outer shell of the mixing zone 233 in the shape of a cone and cooperating with the V-shaped crystal growth device 700, the separated crystals in the evaporative crystallizer 230 can be guided to the V-shaped crystal growth device 700 in the mixing zone 233 for crystal size screening. The structure design of the V-shaped crystal growth device 700 in cooperation with the second raw material liquid inlet 244 allows a small amount of raw material liquid entering from the second raw material liquid inlet 244 to sweep the crystals in the V-shaped crystal growth device 700. The crystals with smaller particle size and lighter mass are blown up by the raw material liquid and continue to collide and grow in the solution, while the crystals with larger particle size and heavier mass are retained in the V-shaped crystal growth device 700 and then discharged to the separation unit 400 for solid-liquid separation.

[0098] In the preferred embodiment, the V-shaped angle of the V-shaped crystal growth device 700 is 120-165°, more preferably 150-165°, and most preferably 165°. By controlling the V-shaped angle of the V-shaped crystal growth device 700 within the above range, the growth of the crystals is facilitated.

[0099] In the preferred embodiment, a viewing window (not shown in the figure, for example, the material of the viewing window can be transparent glass or transparent industrial plastic) is arranged above the crystal growth device. Through the viewing window, the crystal growth in the V-shaped crystal growth device 700 can be observed, which is beneficial for confirming the time when the liquid in the evaporative crystallizer 230 is discharged to the separation unit 400.

[0100] Please continue to refer to Figure 2, and / or, the evaporative crystallizer 230 is further provided with a clear liquid outlet 245, the clear liquid outlet 245 is located at the mixing zone 233 and is communicated with the first raw material liquid inlet 241 of the humidification tower 200 through a pipeline.

[0101] Since the raw material liquid after being heated will form solid crystals after entering the evaporative crystallizer 230, the solid crystals will sink downward due to gravity, that is, accumulate in the crystallization zone 234, and the upper part of the solution in the mixing zone 233 has a low salt content. By transporting this part of the liquid with low salt content back to the first raw material liquid inlet 241 for recycling, not only can the overall temperature in the humidification tower 200 be stabilized to avoid the temperature in the humidification tower 200 being reduced after a period of time to affect the crystallization process, but also the water in the clear liquid can be returned to the falling film tube part 210 for heating, so that more solvent is transferred to the gas, further improving the crystallization capacity of the raw material liquid.

[0102] Due to the design of the falling film tube part 210 in the humidification tower 200, the overall temperature in the humidification tower 200 is relatively high, so the water-carrying capacity of the gas in the humidification tower 200 is increased. Through the design of the ultrasonic generator 270, the falling film tube part 210 and the humidification tower filler layer 220, more solvent in the raw material liquid is transferred to the gas, and the gas in the humidification tower 200 is hot and saturated.

[0103] Please refer to Figure 1 , Figure 2 and Figure 8 , the evaporative crystallizer 230 is provided with a first gas outlet 243 on the side close to the humidification tower filler layer 220, that is, the evaporative zone 232 of the evaporative crystallizer 230 is provided with the first gas outlet 243; the humidification tower 200 is further provided with a first gas inlet 242 on the side close to the falling film tube part 210, and the dehumidification unit 300 includes a dehumidification tower 310, the dehumidification tower 310 includes a second gas inlet 311 and a second gas outlet 312, the first gas outlet 243 and the second gas inlet 311 are communicated, and the second gas outlet 312 and the first gas inlet 242 are communicated, so that the humidification tower 200 and the dehumidification tower 310 are communicated, realizing the circulation of the normal pressure gas in the humidification tower 200 and the dehumidification tower 310.

[0104] The hot and saturated gas in the humidification tower 200 that is full of solvent flows out from the first gas outlet 243 of the evaporative zone 232, enters the dehumidification tower 310 from the second gas inlet 311, and is treated in the dehumidification tower 310 to reduce the water content in the hot and saturated gas. The solvent in the hot and saturated gas is separated from the gas in the dehumidification tower 310, the gas returns to the humidification tower 200 for recycling, the salt content in the solvent is extremely low, the electrical conductivity is 100-120 μs / cm, the purity is high, and meets the discharge standard, so it can be directly discharged or connected to other processes (such as returned to the production system of chemical materials) for reuse.

[0105] Referring to Figure 8 In some preferred embodiments, in order to adapt to the process of the atmospheric pressure low-temperature evaporation crystallization device 10, the second gas inlet 311 is located at the lower part of the dehumidification tower 310, and the second gas outlet 312 is located at the upper part of the dehumidification tower 310, so that the gas can circulate through the natural overflow process in the dehumidification tower 310.

[0106] Referring to Figure 2 At the same time, the first gas outlet 243 is located at the evaporation zone 232 of the evaporation crystallizer 230, so it can be understood that the first gas outlet 243 is located at the lower part of the humidification tower 200, and in order to ensure the gas-liquid contact effect, the first gas inlet 242 is located at the top of the humidification tower 200, so that the gas-liquid contact process in the humidification tower 200 is counter-flow contact, and the raw material liquid always maintains a low concentration during the evaporation process, thereby reducing the material viscosity and ion supersaturation, and inhibiting the formation of scale from the source. Therefore, the position design of the first gas outlet 243 and the first gas inlet 242 is also beneficial to the anti-scaling effect of the falling film tube part 210.

[0107] In some preferred embodiments, in order to ensure uniform distribution of the gas in the humidification tower 200, a gas distributor 290 is further arranged in the humidification tower 200, and the gas distributor 290 is located below the first gas inlet 242.

[0108] Referring to Figure 6 and Figure 7 In some embodiments, in order to adjust and control the content of the gas in the humidification tower 200, a gas opening adjusting assembly is arranged at the first gas outlet 243, and the gas opening adjusting assembly includes any one of a louver adjusting assembly 250 or a positioning pin.

[0109] In some preferred embodiments, the gas opening adjusting assembly is the louver adjusting assembly 250, and the louver adjusting assembly 250 includes a fixed part 251, a plurality of openings are formed in the fixed part 251, and each opening is provided with an adjusting part 252. The adjusting part 252 can selectively move relative to the fixed part 251 to open or close the opening, adjust the opening degree of the opening in the fixed part 251, and thereby adjust the flow of the gas from the humidification tower 200 into the dehumidification tower 310.

[0110] In some preferred embodiments, the opening degree of the opening can be adjusted from 0° to 90°, and the higher the degree, the larger the opening degree of the opening.

[0111] Among them, the movement process of the adjusting part 252 of the louver adjusting assembly 250 relative to the fixed part 251 can be adjusted through the existing structure.

[0112] In some embodiments, the number of openings on the fixing member 251 is at least two, preferably 5-15, and more preferably 5-10.

[0113] In some embodiments, the first gas outlet 243 is an annular structure at the upper part of the evaporative crystallizer 230, and the fixing member 251 and the adjusting member 252 are arranged in the first gas outlet 243. Therefore, the fixing member 251 is annular, and the adjusting member 252 is fan-shaped.

[0114] Please refer to Figure 6 In some preferred embodiments, a humidifying tower demister 260 is arranged at the first gas outlet 243, below the gas opening adjusting assembly. After the gas from the evaporation zone 232 enters the first gas outlet 243, it needs to pass through the humidifying tower demister 260 to remove the fine liquid droplets entrained in the gas, so as to avoid the salt in the fine liquid droplets entering the dehumidifying tower 310 with the gas, and ensure the purity of the liquid separated in the dehumidifying tower 310.

[0115] In optional embodiments, the humidifying tower demister 260 includes any one of a wire mesh demister or a spray head, and the thickness of the wire mesh demister is 40-80 mm.

[0116] Please refer to Figure 1 In some preferred embodiments, an air induction fan 500 is arranged on the pipeline connecting the first gas outlet 243 and the second gas inlet 311 and / or the pipeline connecting the second gas outlet 312 and the first gas inlet 242, to assist the circulation of the gas in the humidifying tower 200 and the dehumidifying tower 310, and to carry the solvent in the humidifying tower 200 out of the separation.

[0117] Preferably, the air induction fan 500 can be an external motor type mixed flow pipeline air induction fan 500, and the fan rotating shaft is connected with an external motor through a transmission shaft. In other embodiments, the air induction fan 500 can also be other types of air induction fan 500, as long as it can ensure the normal pressure circulation of the gas in the humidifying tower 200 and the dehumidifying tower 310.

[0118] In some preferred embodiments, the dehumidifying tower 310 removes the water in the hot saturated humid gas by changing the temperature of the gas. Since the higher the temperature of the gas, the stronger the water carrying capacity, and the lower the temperature of the gas, the weaker the water carrying capacity, the solvent in the hot saturated humid gas can be separated from the gas by reducing the temperature of the hot saturated humid gas in the dehumidifying tower 310, and the obtained gas is a cold saturated humid gas, and the water content in the cold saturated humid gas is lower than that in the hot saturated humid gas, so as to realize the separation of the solvent in the raw material liquid.

[0119] Therefore, the dehumidifying unit 300 further includes a heat exchanger 320, and the dehumidifying tower 310 is connected with the heat exchanger 320 through a pipeline, so as to reduce the temperature of the gas in the dehumidifying tower 310.

[0120] Please refer to Figure 8 In some preferred embodiments, in order to ensure the cooling effect of the heat saturated moisture, the dehumidification tower 310 is provided with a dehumidification tower filler layer 313, and a dehumidification tower spray head 314 is arranged above the dehumidification tower filler layer 313. The dehumidification tower spray head 314 is in communication with the outlet of the heat exchanger 320 through a pipeline. The dehumidification tower 310 is also provided with a solution outlet 315, which is in communication with the inlet of the heat exchanger 320.

[0121] It can be understood that the outlet and the inlet of the heat exchanger 320 are both outlets and inlets for the gas, and the heat exchanger 320 should also have the outlets and inlets of the heat exchange medium to realize the cooling process of the gas.

[0122] In some preferred embodiments, in order to reduce the water content in the heat saturated moisture as much as possible, the number of the dehumidification tower filler layers 313 is multiple, and a dehumidification tower spray head 314 is arranged above each dehumidification tower filler layer 313, and each dehumidification tower spray head 314 is in communication with the outlet of the heat exchanger 320 through a pipeline.

[0123] In some preferred embodiments, the volume of each dehumidification tower filler layer 313 is 0.2-0.4 m 3 The specific surface area is 120-180 m 2 / m 3 The filler in the dehumidification tower filler layer 313 can be regular corrugated filler, and the material can be any one of PP, PVC or ceramic.

[0124] In some preferred embodiments, the dehumidification tower 310 is also provided with a dehumidification tower demister 316, which is arranged above the dehumidification tower filler layer 313, so that when the gas passes through the dehumidification tower demister 316, small water droplets are filtered out.

[0125] In some preferred embodiments, a dehumidification tower spray head 314 is also arranged above the dehumidification tower demister 316, the dehumidification tower demister 316 is a wire mesh demister, and the thickness of the dehumidification tower demister 316 is 40-80 mm.

[0126] In some preferred embodiments, the solution outlet 315 is located at the bottom of the dehumidification tower 310, so that the obtained solvent can fall by gravity and be discharged from the solution outlet 315.

[0127] Please refer to Figure 1In some preferred embodiments, in order to improve the heat exchange efficiency of the heat exchanger 320, the dehumidification unit 300 further comprises a solution buffer tank 330, an inlet of the solution buffer tank 330 being in communication with the solution outlet 315, and an outlet of the solution buffer tank 330 being in communication with an inlet of the heat exchanger 320. The solvent separated by the dehumidification tower 310 is temporarily stored in the solution buffer tank 330, and then cooled by the heat exchanger 320 before being returned to the dehumidification tower 310 to cool the gas in the dehumidification tower 310.

[0128] In some preferred embodiments, in order to ensure that the separated solvent can be returned to the dehumidification tower 310 for recycling, a solution circulation pump 340 is further arranged on the pipeline in communication between the outlet of the solution buffer tank 330 and the inlet of the heat exchanger 320.

[0129] In some preferred embodiments, the outlet of the solution buffer tank 330 is further in communication with the external liquid pipeline 20. On the premise that the amount of liquid required for cooling the gas in the dehumidification tower 310 is sufficient, the excess liquid in the solution buffer tank 330 can be discharged through the external liquid pipeline 20.

[0130] In some embodiments, the separation unit 400 comprises at least one of a cyclone 410, a thickener 420, and a centrifuge 430.

[0131] In some preferred embodiments, the separation unit 400 comprises the cyclone 410, the thickener 420, and the centrifuge 430. The inlet of the cyclone 410 is in communication with the brine outlet 231 of the humidification tower 200 through a pipeline, the solid outlet of the cyclone 410 is in communication with the inlet of the thickener 420, the solid outlet of the thickener 420 is in communication with the inlet of the centrifuge 430, and the cyclone 410, the thickener 420, and the centrifuge 430 are each provided with a liquid outlet, and the liquid outlet is in communication with the first raw liquid inlet 241 of the humidification tower 200.

[0132] Therefore, the concentrated solution containing solid salt flowing out of the brine outlet 231 of the humidification tower 200 enters the cyclone 410, the thickener 420, and the centrifuge 430 in sequence through the pipeline, and gradient solid-liquid separation is performed on the concentrated solution containing solid salt. The crystallized solid salt is collected and transferred from the centrifuge 430 to the solid salt storage tank 800, and the supernatant separated is discharged from the liquid outlet of each device and returned to the first raw liquid inlet 241 of the humidification tower 200 for crystallization and separation again.

[0133] In some preferred embodiments, the cyclone 410 can adopt a small cone angle cyclone 410 with a cone angle of 10-20°; the overflow pipe diameter of the cyclone 410 is 0.3-0.4 times the cylinder diameter of the cyclone 410. The centrifuge 430 can be a three-stage pusher centrifuge 430, which can reduce the solid phase moisture content of the filter cake. The thickener 420 can be selected to have a discharge cone installed at the discharge port thereof, and the centrifuge 430 is connected to the discharge cone of the thickener 420 through a pipeline.

[0134] In some preferred embodiments, the separation unit 400 further comprises a liquid storage tank 450, and the liquid outlets are all communicated with the liquid storage tank 450 through pipelines, and the liquid storage tank 450 is communicated with the first raw material liquid inlet 241 through a pipeline.

[0135] In some preferred embodiments, in order to ensure that the supernatant can be smoothly returned to the humidification tower 200, a liquid delivery pump 460 is further arranged on the pipeline communicated between the liquid storage tank 450 and the first raw material liquid inlet 241.

[0136] In some preferred embodiments, in order to ensure that the concentrated solution containing solid salt can be smoothly introduced into the separation unit 400, a humidification tower discharge pump 600 is arranged on the pipeline communicated between the cyclone 410 and the salt liquid outlet 231.

[0137] In some preferred embodiments, in order to ensure the normal use of the atmospheric low-temperature evaporation crystallization device 10, the atmospheric low-temperature evaporation crystallization device 10 further comprises a plurality of detectors (not shown in the figure, which can be installed on any equipment and / or pipeline of the atmospheric low-temperature evaporation crystallization device 10), and the detectors comprise at least one of a pressure detector, a temperature detector, a flow detector and a wind speed detector.

[0138] The pressure detector can be a pressure sensor, the temperature detector can be a temperature transmitter, and the flow detector can be detected by a flow meter in cooperation with a flow metering sensor. Generally, the number of the above detectors can be increased or decreased according to the actual control and data collection needs.

[0139] In the second aspect, the present application provides a separation method of industrial waste brine, which is suitable for the atmospheric low-temperature evaporation crystallization device 10 of any one of the preceding embodiments, and comprises the following steps: introducing a raw material liquid into the humidification tower 200; uniformly distributing the raw material liquid through the falling film pipe liquid distributor 211; rotating the raw material liquid into the first heat exchange channel 2121 of the falling film pipe body 212 through the spiral liquid inlet channel 2112; and heating the raw material liquid after heat exchange with the heat medium in the second heat exchange channel.

[0140] The heated raw material liquid enters the evaporation crystallizer 230 after passing through the humidification tower packing layer 220, and the heated raw material liquid crystallizes in the evaporation crystallizer 230. The crystals obtained by crystallization and the liquid in the evaporation crystallizer 230 enter the separation unit 400 for solid-liquid separation. The liquid separated by the separation unit 400 is returned to the humidification tower 200 for recycling.

[0141] The heated raw material liquid increases the gas temperature in the evaporation crystallizer 230, so that the water content of the gas in the evaporation crystallizer 230 increases. The gas from the first gas outlet 243 of the evaporation crystallizer 230 flows into the dehumidification tower 310 to remove water, and then returns to the humidification tower 200 for recycling.

[0142] The raw material liquid to be treated is in contact with the gas in the humidification tower 200 in series.

[0143] In an optional embodiment, the method for removing water in the dehumidification tower 310 is to cool the gas from the evaporation crystallizer 230.

[0144] And / or, the solid-liquid separation method of the separation unit 400 includes at least one of centrifugation, sedimentation and filtration.

[0145] First embodiment

[0146] The present embodiment provides a normal pressure low temperature evaporation crystallization device 10, comprising the following structure:

[0147] A normal pressure low temperature evaporation crystallization device 10, comprising a raw material liquid storage tank 100, a humidification tower 200, a dehumidification unit 300 and a separation unit 400.

[0148] Please refer to Figure 2 The humidification tower 200 includes a falling film tube part 210, a humidification tower packing layer 220 and an evaporation crystallizer 230 arranged in sequence from top to bottom and integrated into one body. The side of the humidification tower 200 close to the falling film tube part 210, i.e. the upper part of the humidification tower 200, is provided with a first raw material liquid inlet 241, and the first raw material liquid inlet 241 is in communication with the raw material liquid storage tank 100 through a pipeline.

[0149] Please refer to Figure 3 The falling film tube part 210 includes a falling film tube body 212, and the falling film tube body 212 includes a first heat exchange channel 2121 and a second heat exchange channel. The first heat exchange channel 2121 and the second heat exchange channel are heat-exchanged by an interwall. The first heat exchange channel 2121 is used for flowing the raw material liquid to be treated, and the second heat exchange channel is in communication with an external heat medium source, so that the raw material liquid to be treated is heated after passing through the falling film tube body 212.

[0150] In the present embodiment, the external heat medium source connected with the falling film tube body 212 is a residual heat source in other process flow.

[0151] In the embodiment, the surface area of the falling film tube body 212 is 10 m 2 .

[0152] In order to ensure that the raw material liquid to be treated is uniformly distributed in the falling film tube and ensure the warming effect of the raw material liquid to be treated, the falling film tube part 210 further comprises a falling film tube liquid distributor 211.

[0153] In the embodiments as shown in Figure 3 and Figure 4 , in order to ensure the installation stability of the falling film tube part 210, the falling film tube liquid distributor 211 comprises a liquid distribution pipe support 2113 fixed to the inner wall surface of the humidification tower 200, and the thickness of the liquid distribution pipe support 2113 is 16 mm.

[0154] The falling film tube liquid distributor 211 further comprises a liquid distribution pipe 2111, one end of the liquid distribution pipe 2111 is provided with a spiral liquid inlet channel 2112, and the falling film tube liquid distributor 211 communicates with the first heat exchange channel 2121 through the spiral liquid inlet channel 2112. By providing the spiral liquid inlet channel 2112, the raw material liquid to be treated spirally enters the first heat exchange channel 2121 of the falling film tube, increases the flow path of the raw material liquid in the falling film tube, and at the same time, the raw material liquid spirally collides with the inner wall surface of the first heat exchange channel 2121 during the process, which can also increase the turbulence degree of the raw material liquid, thereby improving the heat exchange efficiency of the raw material liquid in the falling film tube.

[0155] The liquid distribution pipe 2111 is fixedly connected with the liquid distribution pipe support 2113, and the first inlet 2115 of the spiral liquid inlet channel 2112 is provided at the connection position. The opening depth of the first inlet 2115 is 12 mm.

[0156] Among them, the liquid distribution pipe support 2113 is fixed with the inner wall surface of the humidification tower 200 by bolt connection, and the liquid distribution pipe 2111 is fixed on the liquid distribution pipe support 2113 by welding, and the first inlet 2115 of the spiral liquid inlet channel 2112 is not blocked.

[0157] The number of liquid distribution pipes 2111 is 71, and a plurality of liquid distribution pipes 2111 are uniformly and intervaliy arranged on the liquid distribution pipe support 2113. The number of corresponding first heat exchange channels 2121 is also 71, and a plurality of liquid distribution pipes 2111 and a plurality of first heat exchange channels 2121 are arranged one by one.

[0158] Further, in order to ensure that the raw material liquid to be treated enters the falling film tube from the first inlet 2115, the falling film tube liquid distributor 211 further comprises a liquid distribution pipe cap 2114, and the end of the liquid distribution pipe 2111 away from the spiral liquid inlet channel 2112 is blocked by the liquid distribution pipe cap 2114.

[0159] In the embodiment, the spiral liquid inlet channel 2112 is located on the outer surface of the liquid distribution pipe 2111, and the inner diameter of the first heat exchange channel 2121 is larger than the outer diameter of the liquid distribution pipe 2111, so that the spiral liquid inlet channel 2112 is located in the first heat exchange channel 2121. When the raw material liquid to be treated enters the first heat exchange channel 2121 through the first inlet 2115, most of the raw material liquid will enter in a spiral manner in the spiral liquid inlet channel 2112, and a small part of the raw material liquid will be thrown out of the spiral liquid inlet channel 2112 due to excessive centrifugal force, contact the inner wall of the first heat exchange channel 2121 and rebound, increase the turbulence degree of the raw material liquid, reduce the dynamic viscosity of the raw material liquid, facilitate the transfer of solvent molecules in the raw material liquid to the gas, increase the possibility of capturing solvent in the gas in the humidification tower 200, and facilitate the subsequent crystallization process.

[0160] In the embodiment, the liquid distribution pipe 2111 has a horn-shaped end of the spiral liquid inlet channel 2112, which improves the rotational power of the raw material liquid in the first heat exchange channel 2121 and improves the heat exchange capacity of the raw material liquid and the heat medium in the second heat exchange channel.

[0161] In the embodiment, since the raw material liquid to be treated is mostly a salt solution, in order to avoid crystallization of a small part of salt in the falling film pipe part 210 during evaporation crystallization, thereby blocking the spiral liquid inlet channel 2112, a hydrophilic wear-resistant coating is arranged on the inner wall surface of the spiral liquid inlet channel 2112, which is a carbon nanotube-ceramic composite coating.

[0162] In the embodiment, the outer wall surface of the humidification tower 200 is provided with an ultrasonic generator 270, and the ultrasonic generator 270 is arranged correspondingly to the falling film pipe part 210. The unit power of the ultrasonic generator 270 is 30 W / m 2 , the total power is 200 W, and the frequency is 20-40 Hz.

[0163] In the embodiment, in order to ensure uniform distribution of the raw material liquid to be treated in the falling film pipe part 210, a humidification tower spray head 280 is further arranged in the humidification tower 200, and the humidification tower spray head 280 is located above the falling film pipe part 210 and is in communication with the first raw material liquid inlet 241 through a pipeline.

[0164] The raw material liquid to be treated is heated in the falling film pipe part 210, so the temperature of the gas (such as air) in the humidification tower 200 is also increased, the water carrying capacity of the gas is increased, and the structure design of the falling film pipe part 210 makes the solvent in the raw material liquid to be treated transfer to the gas, so that the water content in the heated raw material liquid is reduced, which is beneficial to the subsequent crystallization.

[0165] The raw material liquid with a higher temperature enters the humidification tower packing layer 220, and in the embodiment, the volume of the humidification tower packing layer 220 is 0.2 m 3Inside which is filled with regular corrugated filler, material PP, specific surface area is 150 m 2 / m 3 .

[0166] The humidification tower filler layer 220 is located between the falling film tube part 210 and the evaporative crystallizer 230. By arranging the humidification tower filler layer 220, the heated raw material liquid is distributed in the humidification tower filler layer 220, the gas-liquid contact area is increased, and the ability of the solvent in the raw material liquid to transfer into the gas is further improved.

[0167] The raw material liquid passing through the humidification tower filler layer 220 enters the evaporative crystallizer 230 below it for crystallization.

[0168] The evaporative crystallizer 230 includes an evaporation zone 232, a mixing zone 233 and a crystallization zone 234 connected in sequence, the evaporation zone 232 is communicated with the humidification tower filler layer 220, and the crystallization zone 234 is provided with a crystal growth device, and the opening at the bottom of the crystallization zone 234 is a salt liquid outlet 231.

[0169] The raw material liquid passing through the humidification tower filler layer 220 accumulates in the evaporative crystallizer 230, and the solid solute crystallizes and precipitates, the precipitated crystals collide and grow in the evaporative crystallizer 230, then sink into the crystallization zone 234, and the crystal growth device in the crystallization zone 234 is screened out. The solid salt of sufficient size flows out from the salt liquid outlet 231 at the bottom of the crystallization zone 234, the salt liquid outlet 231 is communicated with the separation unit 400 through a pipeline, and the liquid obtained by the separation unit 400 is returned to the humidification tower 200 for repeated use, so as to improve the desalination capacity of the raw material liquid.

[0170] Please refer to Figure 5 In this embodiment, the outer shell of the mixing zone 233 is in the shape of a cone, the crystal growth device is a V-shaped crystal growth device 700, the edge of the V-shaped crystal growth device 700 is arranged in a spaced manner with the wall surface of the crystallization zone 234, and the crystallization zone 234 is also provided with a second raw material liquid inlet 244. The second raw material liquid inlet 244 is located above the V-shaped crystal growth device 700, and the second raw material liquid inlet 244 is communicated with the raw material liquid storage tank 100 through a pipeline.

[0171] In this embodiment, the diameter of the V-shaped crystal growth device 700 is 1 / 3 of the diameter of the inner wall of the crystallization zone 234, so as to ensure the crystallization effect.

[0172] By setting the shape of the shell of the mixing area 233 as a cone type, cooperating with the V-shaped crystal growth device 700, the crystallization of the raw material liquid precipitated in the evaporation crystallizer 230 can be guided in the mixing area 233 to the V-shaped crystal growth device 700 for grain screening. The structure design of the V-shaped crystal growth device 700 cooperating with the second raw material liquid inlet 244 makes a small amount of raw material liquid entering from the second raw material liquid inlet 244 can sweep the grains in the V-shaped crystal growth device 700, the grains with smaller particle size and lighter quality are blown up by the raw material liquid and continue to collide and grow in the solution, and the grains with larger particle size and heavier quality are waiting to be discharged to the separation unit 400 for solid-liquid separation.

[0173] In the embodiment, the V-shaped cone angle of the V-shaped crystal growth device 700 is 165°. By controlling the V-shaped cone angle of the V-shaped crystal growth device 700 within the above range, the growth of the grains is facilitated.

[0174] In the embodiment, a visual window (not shown in the figure, for example, the material of the visual window part can be transparent glass material or transparent industrial plastic material) is further arranged on the crystallization area 234, and the visual window is located above the crystal growth device. Through the visual window, the grain situation in the V-shaped crystal growth device 700 can be observed, which is conducive to confirming the time when the liquid in the evaporation crystallizer 230 is discharged to the separation unit 400.

[0175] Please continue to refer to Figure 2 In the embodiment, the evaporation crystallizer 230 is further provided with a clear liquid outlet 245, the clear liquid outlet 245 is located at the mixing area 233, and is communicated with the first raw material liquid inlet 241 of the humidification tower 200 through a pipeline.

[0176] After the raw material liquid after being heated enters the evaporation crystallizer 230, solid crystallization will occur, and the solid crystallization will sink downward due to gravity, that is, accumulate in the crystallization area 234, while the upper part of the solution in the mixing area 233 has low salt content. By transporting this part of the liquid with low salt content back to the first raw material liquid inlet 241 for recycling, the overall temperature in the humidification tower 200 can be stabilized, and the crystallization process can be avoided after a period of time. The temperature in the humidification tower 200 is reduced, and the water in the clear liquid can be returned to the falling film pipe part 210 for heating again, so that more solvent is transferred to the gas, and the crystallization capacity of the raw material liquid is further improved.

[0177] Due to the design of the falling film pipe part 210 in the humidification tower 200, the overall temperature in the humidification tower 200 is relatively high, so the water carrying capacity of the gas in the humidification tower 200 is improved. Through the design of the ultrasonic generator 270, the falling film pipe part 210 and the humidification tower filler layer 220, more solvent in the raw material liquid is transferred to the gas, and the gas in the humidification tower 200 is hot and saturated.

[0178] Please refer to Figure 1 , Figure 2 and Figure 8 , the evaporation crystallizer 230 is provided with a first gas outlet 243 near the side of the humidification tower packing layer 220, that is, the evaporation zone 232 of the evaporation crystallizer 230 is provided with the first gas outlet 243; the humidification tower 200 is also provided with a first gas inlet 242 near the side of the falling film tube part 210, and the dehumidification unit 300 includes a dehumidification tower 310, the dehumidification tower 310 includes a second gas inlet 311 and a second gas outlet 312, the first gas outlet 243 and the second gas inlet 311 are communicated, and the second gas outlet 312 and the first gas inlet 242 are communicated, so that the humidification tower 200 and the dehumidification tower 310 are communicated, realizing the circulation of the normal pressure gas in the humidification tower 200 and the dehumidification tower 310.

[0179] The hot saturated wet gas filled with solvent in the humidification tower 200 flows out from the first gas outlet 243 of the evaporation zone 232, enters the dehumidification tower 310 from the second gas inlet 311, is treated by the dehumidification tower 310, the water content in the hot saturated wet gas is reduced, and the solvent in the hot saturated wet gas is separated from the gas in the dehumidification tower 310. The gas returns to the humidification tower 200 for recycling, the salt content in the solvent is extremely low, the conductivity is 120 μs / cm, the purity is high, and the discharge standard is met, so that the solvent can be directly discharged or connected to other processes (for example, returned to the production system of chemical materials) for recycling.

[0180] Please refer to Figure 8 In this embodiment, in order to adapt to the process of the normal pressure low-temperature evaporation crystallization device 10, the second gas inlet 311 is located at the lower part of the dehumidification tower 310, and the second gas outlet 312 is located at the upper part of the dehumidification tower 310, so that the gas circulation in the dehumidification tower 310 can be realized through the natural overflow process.

[0181] Please refer to Figure 2 At the same time, the first gas outlet 243 is in the evaporation zone 232 of the evaporation crystallizer 230, so it can be understood that the first gas outlet 243 is located at the lower part of the humidification tower 200, and in order to ensure the gas-liquid contact effect, the first gas inlet 242 is located at the top of the humidification tower 200, so that the gas-liquid contact process in the humidification tower 200 is counter-current contact, the raw material liquid always maintains a low concentration during the evaporation process, the material viscosity and ion supersaturation are reduced, and the scale formation is inhibited from the source. Therefore, the position design of the first gas outlet 243 and the first gas inlet 242 is also beneficial to the scale prevention effect of the falling film tube part 210.

[0182] In this embodiment, in order to ensure the uniform distribution of the gas in the humidification tower 200, a gas distributor 290 is also arranged in the humidification tower 200, and the gas distributor 290 is located below the first gas inlet 242.

[0183] Please refer to Figure 6 and Figure 7 In this embodiment, in order to adjust and control the content of the gas in the humidification tower 200, a gas opening adjusting assembly is arranged at the first gas outlet 243, which is a louver adjusting assembly 250. The louver adjusting assembly 250 includes a fixed part 251, and a plurality of openings are formed on the fixed part 251. An adjusting part 252 is arranged on the surface of each opening. The adjusting part 252 can selectively move relative to the fixed part 251 to open or close the opening, adjust the opening degree of the opening on the fixed part 251, and thus adjust the flow of the gas from the humidification tower 200 into the dehumidification tower 310.

[0184] In this embodiment, the opening degree of the opening can be adjusted from 0° to 90°. The higher the degree, the larger the opening degree of the opening. The opening degree can be adjusted by an external handle. Each gear can adjust the opening degree by 11.25°, and there are 8 gears. Positioning holes and positioning pins are arranged to cooperate with the locking opening position.

[0185] In this embodiment, the movement of the adjusting part 252 of the louver adjusting assembly 250 relative to the fixed part 251 can be adjusted by the existing structure.

[0186] In this embodiment, the number of openings on the fixed part 251 is 8.

[0187] In this embodiment, the first gas outlet 243 is an annular structure at the upper part of the evaporative crystallizer 230. The fixed part 251 and the adjusting part 252 are arranged in the first gas outlet 243. Therefore, the fixed part 251 is annular, and the adjusting part 252 is fan-shaped.

[0188] Please refer to Figure 6 In this embodiment, the first gas outlet 243 is also provided with a humidification tower demister 260, which is a wire mesh demister. The thickness of the wire mesh demister is 60 mm.

[0189] The humidification tower demister 260 is located below the gas opening adjusting assembly. After the gas enters the first gas outlet 243 from the evaporation zone 232, it needs to pass through the humidification tower demister 260 to remove the fine droplets entrained in the gas, so as to avoid the salt in the small droplets entering the dehumidification tower 310 with the gas, and ensure the purity of the liquid separated in the dehumidification tower 310.

[0190] Please refer to Figure 1 In this embodiment, an induced draft fan 500 is arranged on the pipeline connecting the first gas outlet 243 and the second gas inlet 311 and the pipeline connecting the second gas outlet 312 and the first gas inlet 242, so as to assist the circulation of the gas in the humidification tower 200 and the dehumidification tower 310, and carry out the separation of the solvent in the humidification tower 200.

[0191] In the embodiment, the air blower 500 is a high-temperature and high-humidity resistant mixed-flow air blower, with an air volume of 3000 m 3 / h, an air pressure of 2200 Pa, and a power cable connected to the air blower 500 through a stainless steel pipe.

[0192] In the embodiment, the moisture removal tower 310 removes water in the hot saturated moisture by changing the temperature of the gas. Since the higher the temperature of the gas, the stronger the water-carrying capacity, and the lower the temperature of the gas, the weaker the water-carrying capacity, the solvent in the hot saturated moisture can be separated from the gas by reducing the temperature of the hot saturated moisture in the moisture removal tower 310, and the obtained gas is cold saturated moisture, which has a lower water content than the hot saturated moisture, thereby realizing the separation of the solvent in the raw material liquid.

[0193] Therefore, the moisture removal unit 300 further comprises a heat exchanger 320, and the moisture removal tower 310 and the heat exchanger 320 are connected through a pipeline to reduce the temperature of the gas in the moisture removal tower 310.

[0194] Please refer to Figure 8 In the embodiment, in order to ensure the cooling effect of the hot saturated moisture, the moisture removal tower 310 is provided with a moisture removal tower packing layer 313, and the moisture removal tower packing layer 313 is provided with a moisture removal tower spray head 314 above it, the moisture removal tower spray head 314 is connected to the outlet of the heat exchanger 320 through a pipeline, and the moisture removal tower 310 is further provided with a solution outlet 315, which is connected to the inlet of the heat exchanger 320.

[0195] It should be understood that the outlet and inlet of the heat exchanger 320 are used for the outlet and inlet of the gas, and the heat exchanger 320 should also have the outlet and inlet of the heat medium to realize the cooling process of the gas.

[0196] In the embodiment, in order to reduce the water content in the hot saturated moisture as much as possible, the number of the moisture removal tower packing layers 313 is two, and the total volume of the two moisture removal tower packing layers 313 is 0.6 m 3 , which is filled with regular corrugated packing, and the specific surface area is 150 m 2 / m 3 .

[0197] Each moisture removal tower packing layer 313 is provided with a moisture removal tower spray head 314 above it, and each moisture removal tower spray head 314 is connected to the outlet of the heat exchanger 320 through a pipeline.

[0198] In the embodiment, the moisture removal tower 310 is further provided with a moisture removal tower demister 316 above the moisture removal tower packing layer 313, so that small water droplets in the gas are filtered out when the gas passes through the moisture removal tower demister 316.

[0199] In the embodiment, the dehumidification tower demister 316 is a wire mesh demister, and a dehumidification tower spray head 314 is arranged above the dehumidification tower demister 316.

[0200] In the embodiment, the solution outlet 315 is located at the bottom of the dehumidification tower 310, so that the obtained solvent is separated and falls by gravity and is discharged from the solution outlet 315.

[0201] Please refer to Figure 1 In the embodiment, in order to improve the heat exchange efficiency of the heat exchanger 320, the dehumidification unit 300 further comprises a solution buffer tank 330, the inlet of the solution buffer tank 330 is communicated with the solution outlet 315, and the outlet of the solution buffer tank 330 is communicated with the inlet of the heat exchanger 320. The solvent separated by the dehumidification tower 310 is temporarily stored in the solution buffer tank 330, and then is cooled by the heat exchanger 320 and returned to the dehumidification tower 310 to cool the gas in the dehumidification tower 310.

[0202] In the embodiment, in order to ensure that the separated solvent can be returned to the dehumidification tower 310 for recycling, a solution circulating pump 340 is arranged on the pipeline communicated with the outlet of the solution buffer tank 330 and the inlet of the heat exchanger 320.

[0203] In the embodiment, the outlet of the solution buffer tank 330 is further communicated with the external liquid pipeline 20. On the premise that the amount of liquid required for cooling the gas in the dehumidification tower 310 is sufficient, the excess liquid in the solution buffer tank 330 can be discharged through the external liquid pipeline 20.

[0204] In the embodiment, the separation unit 400 comprises a cyclone 410, a thickener 420 and a centrifuge 430. The inlet of the cyclone 410 is communicated with the brine outlet 231 of the humidification tower 200 through a pipeline, the solid outlet of the cyclone 410 is communicated with the inlet of the thickener 420, the solid outlet of the thickener 420 is communicated with the inlet of the centrifuge 430, and the cyclone 410, the thickener 420 and the centrifuge 430 are all provided with liquid outlets, which are all communicated with the first raw liquid inlet 241 of the humidification tower 200.

[0205] Therefore, the concentrated solution containing solid salt flowing out of the brine outlet 231 of the humidification tower 200 enters the cyclone 410, the thickener 420 and the centrifuge 430 in sequence through the pipeline, and gradient solid-liquid separation is performed on the concentrated solution containing solid salt, the crystallized solid salt is collected and transferred from the centrifuge 430 to the solid salt storage tank 800, and the supernatant separated is discharged from the liquid outlets of the devices and returned to the first raw liquid inlet 241 of the humidification tower 200 for crystallization separation again.

[0206] In the embodiment, the cyclone 410 is a small cone angle cyclone 410 with a cone angle of 15°; the overflow pipe diameter of the cyclone 410 is 0.34 times the cylinder diameter of the cyclone 410. The centrifuge 430 is a three-stage pusher centrifuge 430, which can reduce the solid phase moisture content of the filter cake. The thickener 420 is selected to have a discharge cone installed at the discharge port thereof, and the centrifuge 430 is connected to the discharge cone of the thickener 420 through a pipeline.

[0207] In the embodiment, the separation unit 400 further comprises a liquid storage tank 450, and the liquid outlets are all communicated with the liquid storage tank 450 through pipelines, and the liquid storage tank 450 is communicated with the first raw liquid inlet 241 through a pipeline.

[0208] In the embodiment, in order to ensure that the supernatant can be smoothly returned to the humidification tower 200, a liquid delivery pump 460 is further arranged on the pipeline communicated between the liquid storage tank 450 and the first raw liquid inlet 241.

[0209] In the embodiment, in order to ensure that the concentrated solution containing solid salt can be smoothly introduced into the separation unit 400, a humidification tower discharge pump 600 is arranged on the pipeline communicated between the cyclone 410 and the salt liquid outlet 231.

[0210] In the embodiment, in order to ensure the normal use of the atmospheric low-temperature evaporation crystallization device 10, the atmospheric low-temperature evaporation crystallization device 10 further comprises a plurality of detectors (not shown in the figure, which can be installed on any equipment and / or pipeline of the atmospheric low-temperature evaporation crystallization device 10), and the detectors comprise at least one of a pressure detector, a temperature detector, a flow detector and a wind speed detector.

[0211] Please refer to Figure 9 The embodiment further provides a separation method of industrial waste brine, which is suitable for the atmospheric low-temperature evaporation crystallization device 10, and the specific process is as follows:

[0212] All electrical and instrumental elements in the atmospheric low-temperature evaporation crystallization device 10 are controlled to be turned on and off through external control switches.

[0213] About 1 / 3 volume of clean water is pre-added into the solution buffer tank 330 as the cooling working liquid of the dehumidification tower 310.

[0214] The second heat exchange channel inlet 2123 of the falling film tube body 212 is connected with an external exhaust steam pipeline, and the second heat exchange channel outlet 2122 is connected with an external condensate pipeline, so that the exhaust gas and other heat exchange media are cooled and flow into the external condensate pipeline after heat exchange in the falling film tube body 212, and the heat of the exhaust gas is absorbed again.

[0215] The inlet of the heat exchange medium of the heat exchanger 320 is connected with the outside circulating water upwater pipeline, the outlet of the heat exchange medium is connected with the outside circulating water backwater pipeline, and the outside circulating water upwater pipeline and the outside circulating water backwater pipeline are connected and temperature adjustment is realized, so that the heat exchange medium can be recycled.

[0216] After the above work is completed, the raw material liquid to be treated is introduced into the raw material liquid storage tank 100. When the volume of the raw material liquid to be treated in the raw material liquid storage tank 100 reaches 80%, the raw material liquid is stopped, and the raw material liquid conveying pump is started to convey the raw material liquid to be treated from the first raw material liquid inlet 241 to the humidification tower 200 at a flow rate of 1-2 m³ / h. 3 / h flow rate. The raw material liquid to be treated is uniformly sprayed on the falling film pipe liquid distributor 211 through the humidification tower spray head 280.

[0217] The raw material liquid to be treated enters the spiral liquid inlet channel 2112 from the first inlet 2115 of the liquid distribution pipe 2111 and enters the falling film pipe liquid distributor 211 in the form of spiral flow. A small part of the fluid is thrown to the inner wall surface of the first heat exchange channel 2121 of the falling film pipe body 212 in the spiral liquid inlet channel 2112 due to excessive centrifugal force and is bounced back by the inner wall surface of the falling film pipe body 212 to combine with the raw material liquid in the spiral liquid inlet channel 2112, thereby increasing the turbulence degree of the raw material liquid and reducing the dynamic viscosity of the raw material liquid, which is beneficial to the diffusion of solvent molecules in the raw material liquid to the gas in the humidification tower 200.

[0218] After the raw material liquid rotates in the first heat exchange channel 2121 and exchanges heat with the heat exchange medium in the second heat exchange channel, the raw material liquid is heated and flows from the first heat exchange channel 2121 to the humidification tower packing layer 220. Due to the uniform distribution of the raw material liquid by the falling film pipe liquid distributor 211, the raw material liquid is also uniformly sprayed on the humidification tower packing layer 220 when it flows from the first heat exchange channel 2121 to the humidification tower packing layer 220, and flows through the packing pores of the humidification tower packing layer 220. The surface area of the raw material liquid increases, which is more beneficial to the diffusion of solvent molecules to the gas in the humidification tower 200, and strengthens the evaporation effect of the raw material liquid.

[0219] The raw material liquid flowing out of the humidification tower packing layer 220 enters the evaporation crystallizer 230, and the liquid level rises from the crystallization zone 234 to the mixing zone 233 in the evaporation crystallizer 230. When the liquid level in the evaporation crystallizer 230 reaches 50% of the total liquid level height of the evaporation crystallizer 230, the conveying pump is started, and the flow rate is set to 2-3 m³ / h. The liquid in the upper layer of the evaporation crystallizer 230 is pumped from the clear liquid outlet 245 to the first raw material liquid inlet 241, realizing the circulation treatment of the raw material liquid. The temperature of the falling film pipe body 212 gradually rises, which is beneficial to the evaporation of the raw material liquid. At the same time, the conveying flow rate of the raw material liquid conveying pump is set to 0.1-0.2 m³ / h.

[0220] Open the louvered adjustment assembly 250 on the first gas outlet 243, adjust the opening degree of the opening on the fixing member 251 to 45°, lock the position of the adjustment member 252, start the air blower 500 on the gas circulation pipeline of the humidification tower 200 and the dehumidification tower 310, and set the air speed to 1-5 m / s to realize the normal pressure air circulation in the humidification tower 200 and the dehumidification tower 310.

[0221] When the temperature in the humidification tower 200 reaches 60°C, the ultrasonic generator 270 is started, and the solution circulation pump 340 is started to realize the solution circulation between the dehumidification tower 310 and the heat exchanger 320.

[0222] The heat exchange process between the raw material liquid and the falling film tube in the humidification tower 200 increases the temperature of the gas in the humidification tower 200, and the vigorous heat motion of the solvent in the humidification tower 200 increases, part of the solvent diffuses and escapes from the raw material liquid to the gas to form saturated wet gas, and the packing layer 220 of the humidification tower increases the escape area of the solvent in the raw material liquid, which is beneficial to the diffusion and escape of the solvent to the gas. The ultrasonic generator 270 generates micro bubbles in the raw material liquid and breaks them quickly, which reduces the viscosity of the raw material liquid, making it easier for the solvent in the raw material liquid to diffuse and escape to the gas. In addition, due to the micro vibration generated by the ultrasonic generator 270, the falling film tube part 210 is not easy to scale, which increases the thermal efficiency of the humidification tower 200.

[0223] After the above evaporation process, the gas in the humidification tower 200 is hot saturated wet gas, which is discharged from the first gas outlet 243 of the evaporative crystallizer 230 and enters the dehumidification tower 310 under the action of the air blower 500. The hot saturated wet gas rises from the bottom to the top of the dehumidification tower 310, during which it is in countercurrent contact with the low-temperature water sprayed from the dehumidification tower spray head 314 above the dehumidification tower packing layer 313. Based on the characteristic that the saturation humidity of air changes with temperature, the solvent in the hot saturated wet gas is transferred to the low-temperature water while the temperature of the gas is reduced, and the water load of the gas is reduced to obtain cold saturated wet gas.

[0224] The temperature of the hot saturated wet gas is reduced in the dehumidification tower 310, and the water content is reduced. After the heat and mass transfer between the low-temperature water in the dehumidification tower 310 and the hot saturated wet gas, the temperature of the low-temperature water is increased and it returns to the dehumidification tower 310 after being cooled in the heat exchanger 320 for recycling. As the evaporation process proceeds, the solvent in the raw material liquid is gradually carried into the dehumidification tower 310 by the hot saturated wet gas and remains in the dehumidification tower 310, so the liquid in the solution buffer tank 330 gradually increases. Since it is difficult for the hot saturated wet gas to carry the solute, the water separated in the dehumidification tower 310 has high purity. The excess liquid that meets the circulation in the dehumidification tower 310 can be directly used for external production through external liquid pipeline.

[0225] With the continuous evaporation, the crystals begin to appear in the V-shaped crystal growth device 700 in the crystallization zone 234, at this time, the raw material liquid to be treated is introduced into the crystallization zone 234 from the second raw material liquid inlet 244, the surface of the V-shaped crystal growth device 700 is purged, and the raw material liquid flows through the V-shaped crystal growth device 700, and due to the reaction force, the part of the raw material liquid moves upward along the V-shaped crystal growth device 700 at a speed of 2-7 mm / s, when the weight of the crystal is large enough and reaches the critical point, it is separated from the upward flow in the V-shaped crystal growth device 700 and falls below the V-shaped crystal growth device 700, and the crystal is observed through the visual window, when the crystal reaches 1 / 3 of the visual window, the humidification tower discharge pump 600 is started, and the pressure is controlled at 0.6-1 MPa, the slurry containing crystals in the crystallization zone 234 is sent to the cyclone 410 through the pipeline, the slurry containing crystals is subjected to high-speed centrifugal motion in the cyclone 410, and after centrifugal separation, most of the large-particle-size particles, a small part of the small-particle-size particles, and a small part of the solvent enter the thickener 420, a small part of the large-particle-size particles, most of the small-particle-size particles, and most of the solvent enter the liquid storage tank 450 from the upper part of the cyclone 410 through the pipeline; when the liquid level of the thickener 420 reaches 20% of the volume, the thickener 420 is started, and the slurry separated by the cyclone 410 is further concentrated in the thickener 420, the light liquid overflows from the overflow pipe of the thickener 420 to the liquid storage tank 450, and the heavy liquid is discharged from the thickener 420 to the centrifuge 430 for centrifugal separation, the filter cake separated by the centrifuge 430 enters the solid salt storage tank 800, and the centrifugal mother liquor enters the liquid storage tank 450 through the pipeline. The solution in the liquid storage tank 450 is recycled and reused in the humidification tower 200.

[0226] Test Example 1

[0227] The normal pressure low-temperature evaporation crystallization device 10 of the first embodiment is used to treat salt-containing washing wastewater, i.e., the raw material liquid, and the salt-containing wastewater is a sodium chloride solution with a sodium chloride content of 8%±0.3% treated by a 100 kg / h pilot plant.

[0228] The gas circulation speed in the humidification tower 200 and the dehumidification tower 310 of the normal pressure low-temperature evaporation crystallization device 10 is 2 m / s, the packing spray density is 9-12 m³ / m³, the content of chloride ions in the solution separated by the dehumidification tower 310 is <200 ppm, and the water quality is clear; the particle size D50 of the sodium chloride solid particles separated by the centrifuge 430 is 200 μm, the heat source uses factory secondary steam exhaust, and 95 kg of steam exhaust condensate is collected, achieving the expected design effect.

[0229] Test Example 2

[0230] The normal pressure low-temperature evaporation crystallization device 10 of the first embodiment is used to treat salt-containing washing wastewater, i.e. raw material liquid, the salt-containing wastewater is 100 kg / h of sodium sulfate wastewater disposed by a pilot plant, the sodium sulfate content is 3.6-5%, the COD is 1200-1500 ppm, and the hardness is ≤150.

[0231] The gas circulation speed in the humidification tower 200 and the dehumidification tower 310 of the normal pressure low-temperature evaporation crystallization device 10 is 1.8 m / s, the packing spray density is 10-12 m³ / m³, the sulfate content in the solution obtained by separation of the dehumidification tower 310 is <50 ppm, the COD is <300 ppm, and the water quality is clear; the particle size D50 of the sodium sulfate solid particles separated by the centrifuge 430 is 200 μm, the COD is about 18000 ppm, a heat source uses plant steam condensate (temperature ≥97 ℃), and the expected design effect is achieved.

[0232] The above is only a preferred embodiment of the present application and is not used to limit the present application, and the present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An atmospheric pressure low-temperature evaporation crystallization apparatus, characterized in that, Includes raw material storage tank, humidification tower, dehumidification unit and separation unit; The humidification tower includes a falling film tube section, a humidification tower packing layer, and an evaporator crystallizer, which are arranged sequentially from top to bottom and integrated into one unit. A first raw material liquid inlet is provided on the side of the humidification tower near the falling film tube section. The first raw material liquid inlet is connected to the raw material liquid storage tank through a pipeline. The falling film tube section includes a falling film tube distributor and a falling film tube body. The falling film tube body includes a first heat exchange channel and a second heat exchange channel. The falling film tube distributor includes a distribution tube. One end of the distribution tube is provided with a spiral liquid inlet channel. The falling film tube distributor is connected to the first heat exchange channel through the spiral liquid inlet channel. The second heat exchange channel is connected to an external heat medium source. The dehumidification unit includes a dehumidification tower, which includes a second gas inlet and a second gas outlet; the humidification tower is also provided with a first gas inlet on the side near the falling film tube section, and the evaporator crystallizer is provided with a first gas outlet on the side near the packing layer of the humidification tower. The first gas outlet and the second gas inlet are connected, and the second gas outlet and the first gas inlet are connected, so that the humidification tower and the dehumidification tower are connected. The evaporator crystallizer has a brine outlet on the side away from the first gas outlet. The brine outlet is connected to the separation unit through a pipe, and the liquid obtained by the separation unit is returned to the humidification tower. The falling film tube liquid distributor also includes a liquid distribution tube support and a liquid distribution tube cap. The liquid distribution tube support is fixed inside the humidification tower. The liquid distribution tube is fixedly connected to the liquid distribution tube support, and the connection point is provided with the first inlet of the spiral liquid inlet channel. The end of the liquid distribution tube away from the spiral liquid inlet channel is sealed by the liquid distribution tube cap. The inner diameter of the first heat exchange channel is larger than the outer diameter of the liquid distribution pipe, so that the spiral liquid inlet channel is located inside the first heat exchange channel; The liquid distribution pipe has a flared end with the spiral liquid inlet channel; The inner wall of the spiral liquid inlet channel is provided with a hydrophilic and wear-resistant coating. The hydrophilic wear-resistant coating includes either a carbon nanotube-ceramic composite coating or a silicon carbide coating.

2. The apparatus according to claim 1, characterized in that, The evaporator crystallizer includes an evaporation zone, a mixing zone, and a crystallization zone connected in sequence. The evaporation zone is connected to the packing layer of the humidification tower. A crystal grower is provided in the crystallization zone. The opening at the bottom of the crystallization zone is the brine outlet. And / or, the outer shell of the mixing zone is conical, the crystal grower is a V-shaped crystal grower, the edge of the V-shaped crystal grower is spaced apart from the wall of the crystallization zone, the crystallization zone is also provided with a second raw material liquid inlet, the second raw material liquid inlet is located above the V-shaped crystal grower, and the second raw material liquid inlet is connected to the raw material liquid storage tank through a pipeline; And / or, the V-shaped cone angle of the V-shaped crystal grower is 120~165°; And / or, a viewing window is also provided on the crystallization region, the viewing window being located above the crystal growth device; And / or, the evaporator crystallizer is further provided with a clear liquid outlet, which is located between the salt solution outlet and the first gas outlet, and is connected to the first raw material liquid inlet of the humidification tower through a pipeline.

3. The apparatus according to claim 1 or 2, characterized in that, A gas opening adjustment component is provided at the first gas outlet, and the gas opening adjustment component includes either a louvered adjustment component or a positioning pin. And / or, the louvered adjustment assembly includes a fixing member, the fixing member having multiple openings, and each opening having an adjustment member on its surface, the adjustment member being selectively movable relative to the fixing member to open or close the opening; And / or, the number of openings on the fastener is at least two; And / or, a humidification tower demister is also provided at the first gas outlet, the humidification tower demister being located below the gas opening regulating assembly; And / or, the humidification tower demister includes either a wire mesh demister or a spray head.

4. The apparatus according to claim 1, characterized in that, The humidification tower is also equipped with an ultrasonic generator, which is correspondingly arranged with the falling film tube section. And / or, the ultrasonic generator is located on the outer surface of the humidification tower; And / or, the atmospheric pressure low-temperature evaporation crystallization apparatus further includes multiple detectors, including at least one of a pressure detector, a temperature detector, a flow detector, and a wind speed detector.

5. The apparatus according to claim 1, characterized in that, The humidification tower is also equipped with a humidification tower spray head, which is located above the falling film tube and is connected to the first raw material liquid inlet through a pipe. And / or, the first gas inlet is located at the top of the humidification tower, and a gas distributor is also provided inside the humidification tower, the gas distributor being located below the first gas inlet.

6. The apparatus according to claim 1, characterized in that, The dehumidification unit also includes a heat exchanger, and the dehumidification tower is connected to the heat exchanger through a pipe to cool the gas inside the dehumidification tower; And / or, the dehumidification tower is provided with a dehumidification tower packing layer, and a dehumidification tower spray head is provided above the dehumidification tower packing layer. The dehumidification tower spray head is connected to the outlet of the heat exchanger through a pipe. The dehumidification tower is also provided with a solution outlet, which is connected to the inlet of the heat exchanger. And / or, the number of dehumidification tower packing layers is multiple, each dehumidification tower packing layer is provided with a dehumidification tower spray head above it, and each dehumidification tower spray head is connected to the outlet of the heat exchanger through a pipe; And / or, the dehumidification unit further includes a solution buffer tank, the inlet of which is connected to the solution outlet, and the outlet of which is connected to the inlet of the heat exchanger; And / or, a solution circulation pump is also provided on the pipe connecting the outlet of the solution buffer tank to the inlet of the heat exchanger; And / or, the outlet of the solution buffer tank is also connected to an external liquid pipeline; And / or, an induced draft fan is provided on the pipe connecting the first gas outlet and the second gas inlet and / or on the pipe connecting the second gas outlet and the first gas inlet.

7. The apparatus according to claim 1, characterized in that, The separation unit includes at least one of a hydrocyclone, a thickener, and a centrifuge; And / or, the separation unit includes a hydrocyclone, a thickener, and a centrifuge. The inlet of the hydrocyclone is connected to the brine outlet of the humidification tower via a pipe. The solid outlet of the hydrocyclone is connected to the inlet of the thickener. The solid outlet of the thickener is connected to the inlet of the centrifuge. The hydrocyclone, the thickener, and the centrifuge are all provided with liquid outlets, and the liquid outlets are all connected to the first raw material liquid inlet of the humidification tower. And / or, the separation unit further includes a liquid storage tank, and the liquid outlets are all connected to the liquid storage tank through pipes, and the liquid storage tank is then connected to the first raw material liquid inlet through pipes; And / or, a liquid transfer pump is also provided on the pipeline connecting the liquid storage tank to the first raw material liquid inlet; And / or, a humidification tower discharge pump is installed on the pipe connecting the hydrocyclone to the brine outlet.

8. A method for separating industrial waste brine, characterized in that, Suitable for the atmospheric pressure low temperature evaporation crystallization apparatus as described in any one of claims 1 to 7, comprising introducing a raw material liquid into the humidification tower, wherein the raw material liquid is evenly distributed through the falling film tube distributor, and rotates into the first heat exchange channel of the falling film tube body through the spiral liquid inlet channel, and is heated after exchanging heat with the heat medium in the second heat exchange channel in the first heat exchange channel; After being heated, the raw material liquid enters the evaporator crystallizer after passing through the packing layer of the humidification tower. The heated raw material liquid crystallizes in the evaporator crystallizer. The crystals obtained by crystallization and the liquid in the evaporator crystallizer enter the separation unit for solid-liquid separation. The liquid obtained by the separation unit is returned to the humidification tower for recycling. The heated raw material liquid increases the gas temperature in the evaporator crystallizer, which in turn increases the water content of the gas in the evaporator crystallizer. The gas flows from the first gas outlet of the evaporator crystallizer into the dehumidification tower to remove moisture and then returns to the humidification tower for recycling. The raw material liquid comes into contact with the gas in the humidification tower in a co-current flow.

9. The method according to claim 8, characterized in that, The method for removing moisture in the dehumidification tower is to cool the gas from the evaporator crystallizer; And / or, the solid-liquid separation method of the separation unit includes at least one of centrifugation, sedimentation and filtration.

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