A multi-module thin film evaporator and evaporation process

Abstract

The application relates to a multi-module thin film evaporator and an evaporation process, and belongs to the technical field of wastewater treatment. The multi-module thin film evaporator comprises a steam compressor and multiple evaporation modules. The input end of the steam compressor is connected with a steam inlet pipe, and the output end of the steam compressor is connected with a steam outlet pipe. Each evaporation module comprises a tank body, a thin film group and a condensate collecting mechanism. The thin film group of each evaporation module is provided with multiple groups. Each tank body is connected with a liquid inlet pipeline for feeding liquid. The liquid inlet pipeline is used for flowing to the outer wall of the corresponding multiple thin film groups. Each tank body is connected with a first connecting pipeline between the steam inlet pipe. Each tank body is connected with a second connecting pipeline between the steam outlet pipe. The tank body is connected with a fresh steam inlet pipe for connecting with an external fresh steam source. The application can meet the requirements of simultaneously treating multiple different types of wastewater.

Description

Technical Field

[0001] This application relates to the field of wastewater treatment technology, and in particular to a multi-module thin-film evaporator and evaporation process. Background Technology

[0002] In industrial, chemical, and domestic production sectors, falling film evaporators are commonly used to treat wastewater and concentrate it. The principle of falling film evaporation is as follows: the feed liquid is added from the top of the evaporator and distributed into the pipes via a liquid distributor, causing the liquid to form a film and flow downwards along the pipes. High-temperature steam is then introduced into the device to exchange heat with the liquid in the pipes, causing it to evaporate and concentrate. Finally, concentrated liquid and steam are obtained at the bottom of the device, and then separated by a separator.

[0003] Currently, falling film evaporators on the market can usually only treat one type of wastewater during operation, and cannot meet the needs of treating multiple different types of wastewater simultaneously. Summary of the Invention

[0004] To meet the need for simultaneous treatment of various types of wastewater, this application provides a multi-module thin-film evaporator and evaporation process.

[0005] Firstly, this application provides a multi-module thin-film evaporator, which adopts the following technical solution: A multi-module thin-film evaporator includes a steam compressor and multiple evaporation modules. The input end of the steam compressor is connected to a steam inlet pipe, and the output end of the steam compressor is connected to a steam outlet pipe. Each evaporation module includes a tank, a thin-film assembly, and a condensate collection mechanism. Each evaporation module has multiple thin-film assemblies, which are horizontally spaced within corresponding tanks. Each tank is connected to an inlet pipe for supplying feed liquid, which flows to the outer wall of the corresponding multiple thin-film assemblies. Each tank is connected to the steam inlet pipe via a first connecting pipe, and each tank is connected to the steam outlet pipe via a second connecting pipe. The second connecting pipe is used to guide the steam output from the steam compressor into the corresponding multiple thin-film assemblies. The condensate collection mechanism is used to collect the condensate from the multiple thin-film assemblies in the corresponding tank. The tank is connected to a fresh steam inlet pipe for connecting to an external fresh steam source.

[0006] Preferably, a control valve is installed on each of the first and second connecting pipes.

[0007] Preferably, the bottom of the tank is connected to a concentrate discharge pipe, a concentrate pump is installed on the concentrate discharge pipe, the concentrate discharge pipe is used to connect to an external concentrate buffer tank, a concentration sensor for detecting the concentration of the concentrate is installed on the bottom wall of the tank, the concentration sensor and the concentrate pump are both wirelessly connected to an external control platform, an impeller is rotatably installed in the pipe opening near the bottom of the tank, a scraper is connected to the impeller, and the scraper is provided with bristles that abut against the corresponding bottom wall of the tank.

[0008] Preferably, the scraper includes a fixed rod connected to the impeller and a sliding rod slidably sleeved on the fixed rod. The bristles are disposed on the sliding rod. The fixed rod is provided with an elastic element for pushing the sliding rod to slide away from the fixed rod. A first connecting rope is disposed on the sliding rod. A drum is disposed inside the concentrate discharge pipe. The drum is coaxial with the impeller. The end of the first connecting rope away from the sliding rod is disposed on the drum. When the impeller rotates due to the impact of the concentrate, the first connecting rope winds around the drum. A fixing plate is disposed inside the tank. The fixing plate is located below multiple polymer films inside the corresponding tank. Multiple water passage holes are opened on the fixing plate. The surface of the fixing plate is slidably disposed. The system includes a sliding plate with multiple adjustment holes, each corresponding to a water passage hole. A return spring is installed between the sliding plate and the inner wall of the tank. When the return spring is in its natural state, the adjustment hole aligns with the corresponding water passage hole. A sliding rack is slidably mounted on the inner wall of the tank, with its sliding direction perpendicular to the rotation axis of the impeller. A friction element is installed between the sliding rack and the inner wall of the tank, with the resistance of the friction element being greater than the elastic force of the return spring. A second connecting rope is installed between the sliding rack and the sliding plate, used to pull the sliding plate to move the adjustment hole away from the corresponding water passage hole. The end of the sliding rod is equipped with a toothed block for pushing the sliding rack to slide.

[0009] Preferably, each group of film sets includes multiple polymer films arranged sequentially in the tank along the horizontal direction. Each evaporation module also includes a water equalization mechanism, which corresponds one-to-one with the film sets and is located above the corresponding film sets. Each water equalization mechanism includes a distribution box and a water equalization strip arranged in the tank. The liquid in the inlet pipe flows into multiple distribution boxes in the corresponding tank. The bottom wall of the distribution box has multiple water passage holes. The distribution box is located above the water equalization strip. Multiple water equalization strips are provided, and the arrangement direction of the multiple water equalization strips is parallel to the arrangement direction of the multiple polymer films. Adjacent water equalization strips clamp the upper end of the polymer film. The water equalization strip has multiple water equalization holes.

[0010] Preferably, each of the evaporation modules further includes a gas equalization mechanism, which corresponds one-to-one with the film group. The gas equalization mechanism includes multiple gas equalization strips, which correspond one-to-one with the polymer film. The sidewall of the polymer film is provided with a steam inlet. The gas equalization strip is located in the steam inlet of the corresponding polymer film. Adjacent gas equalization strips are separated by polymer films to form an air inlet plane. The air inlet plane is used to communicate with the corresponding second connecting pipe. The gas equalization strip has multiple gas equalization holes.

[0011] Preferably, the condensate collection mechanism includes a water collector, a condensate collection pipe, and a condensate collection tank. The water collector corresponds one-to-one with the membrane assembly. The lower end of the membrane assembly inside the tank is connected to the corresponding water collector. The condensate collection pipe passes through the tank body. The water collector is connected to the condensate collection pipe. The condensate collection tank is located outside the tank body. The condensate collection pipe is connected to the condensate collection tank.

[0012] Preferably, each of the evaporation modules further includes a first heat exchanger, and the condensate collection tank is connected to the corresponding first heat exchanger. The first heat exchanger is used to exchange heat between the condensate in the condensate collection tank and the feed liquid entering the corresponding inlet pipe.

[0013] Preferably, a circulating liquid pipeline is provided between the bottom of each tank and the top of the corresponding tank. The circulating liquid pipeline is used to transport the concentrated liquid at the bottom of the tank to multiple uniform distribution boxes. A circulating liquid pump is installed on the circulating liquid pipeline.

[0014] Secondly, this application provides a multi-module thin-film evaporation process, which adopts the following technical solution: A multi-module thin-film evaporation process, using the aforementioned multi-module thin-film evaporator, includes the following steps: Step 1: The liquid is fed into the corresponding tank through the inlet pipe; Step 2: Next, the liquid material enters multiple distribution boxes and flows through multiple water holes on the distribution boxes to the water distribution strips below. The liquid material flows evenly through the water distribution holes on the multiple water distribution strips to the outer walls of multiple polymer films. Fresh steam is introduced into the corresponding tank through the fresh steam inlet pipe to evaporate the liquid material on the outer wall of the polymer film. Step 3: The steam evaporated from the outer wall of the polymer film is pressurized and heated by the steam compressor, steam inlet pipe and first connecting pipe and transported to multiple second connecting pipes. Then the steam is evenly introduced into multiple polymer films by the gas equalization mechanism. The steam in the polymer film exchanges heat with the liquid on the outer wall of the polymer film and evaporates. Step 4: Then, the concentrate is obtained at the bottom of the tank. The concentrate at the bottom of the tank enters the corresponding multiple uniform distribution boxes again through the circulating liquid pump and circulating liquid pipeline for evaporation. The concentration of the concentrate at the bottom of the tank is detected by the concentration sensor. When the concentration detection value is greater than the preset value, the concentrate is pumped from the concentrate discharge pipe to the external concentrate buffer tank by the concentrate pump. By adding the reagent to the external concentrate buffer tank, the liquid in the concentrate buffer tank is filtered to separate the solid and liquid. The separated filter residue is collected separately for outsourced treatment, while the separated filtrate is sent to the corresponding raw liquid storage tank, and then heat-exchanged again before entering the corresponding tank. Step 5: The condensate inside the polymer film is collected by a condensate collection mechanism.

[0015] In summary, this application includes the following beneficial technical effects: During operation, various types of liquid feed are fed into different tanks through multiple inlet pipes. The liquid feed then flows onto the outer walls of multiple membrane film groups within the corresponding tanks. Under gravity, the liquid feed flows from top to bottom along the outer walls of the membrane film groups to form a liquid film. High-temperature steam from outside enters the tanks through fresh steam inlet pipes to evaporate the liquid feed. Steam evaporating from the outer walls of the membrane film groups enters the steam inlet pipe through the corresponding first connecting pipe. Then, steam from different tanks is drawn into the steam compressor through the steam inlet pipe for compression. The steam compressor pressurizes and heats the steam and delivers it to the second connecting pipe through the steam outlet pipe. The second connecting pipe delivers the high-temperature steam to the multiple membrane film groups within the corresponding tanks. At this time, the high-temperature steam in the membrane film groups exchanges heat with the liquid feed on the outer walls of the corresponding membrane film groups for evaporation. This cycle continues, resulting in a concentrated liquid feed at the bottom of the tank and condensate collected at the condensate collection mechanism. By using a single low-temperature steam compressor to connect multiple evaporation modules in parallel, the system can meet the needs of simultaneously treating various types of wastewater in actual wastewater treatment. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application.

[0017] Figure 2 This is a schematic diagram of the overall structure from another perspective of an embodiment of this application.

[0018] Figure 3 This is a cross-sectional view of the overall structure of a single evaporation module in an embodiment of this application.

[0019] Figure 4 This is an exploded view of a partial structure inside the tank in an embodiment of this application, mainly used to show the structure of the water distribution mechanism.

[0020] Figure 5 This is a partially exploded cross-sectional view of the polymer film in the embodiments of this application, mainly used to show the internal structure of the polymer film.

[0021] Figure 6 This is a cross-sectional view of the overall structure of the tank in the embodiment of this application.

[0022] Figure 7 This is a structural cross-sectional view of the bottom of the tank in this embodiment of the application, mainly used to show the positional relationship between the fixing plate, the sliding plate and the scraper.

[0023] Explanation of reference numerals in the attached drawings: 1. Steam compressor; 2. Evaporation module; 21. Tank; 22. Water distribution mechanism; 221. Distribution box; 222. Water distribution strip; 23. Thin film assembly; 231. Polymer thin film; 24. Condensate collection mechanism; 241. Water collector; 242. Condensate collection pipe; 243. Condensate collection tank; 26. First heat exchanger; 27. Gas distribution mechanism; 271. Gas distribution strip; 28. Second heat exchanger; 3. Steam inlet pipe; 4. Steam outlet pipe; 5. First connecting pipe; 6. Liquid inlet pipe; 7. Second connecting pipe; 8. Control valve; 9. Concentrate discharge pipe; 10. Concentrate pump body; 11. Impeller; 12. Scraper; 121 12. Fixed rod; 13. Sliding rod; 14. First connecting rope; 15. Drum; 16. Fixed plate; 17. Water passage hole; 18. Sliding plate; 19. Adjusting hole; 20. Return spring; 21. Sliding rack; 32. Guide pulley; 33. Second connecting rope; 34. Tooth block; 35. Water passage hole; 36. Water distribution hole; 37. Air distribution hole; 38. Circulating liquid pipeline; 39. Circulating liquid pump body; 40. Water outlet; 40. Water guide plate; 41. Water channel; 42. Dotted water channel; 43. Wave water channel; 44. Straight water channel; 45. Push spring; 46. Telescopic rod; 47. Steam delivery pipe; 48. Connecting flange; 49. Fresh steam inlet pipe. Detailed Implementation

[0024] The following combination Figures 1-7 This application will be described in further detail.

[0025] This application discloses a multi-module thin-film evaporator. (Refer to...) Figure 1 and Figure 2 The multi-module thin-film evaporator includes a steam compressor 1 and multiple evaporation modules 2. The steam compressor 1 is a low-temperature steam compressor. The input end of the steam compressor 1 is connected to a steam inlet pipe 3, and the output end of the steam compressor 1 is connected to a steam outlet pipe 4.

[0026] Reference Figure 1 and Figure 3Multiple evaporation modules 2 are arranged sequentially and spaced apart along a horizontal direction. In this embodiment, three evaporation modules 2 are provided; in other embodiments, the number of evaporation modules 2 can be set as needed. Specifically, each evaporation module 2 includes a tank 21, a thin film assembly 23, and a condensate collection mechanism 24. The tank 21 has a rectangular cross-section, and its length is parallel to the arrangement direction of the multiple evaporation modules 2. In other embodiments, the length of the tank 21 can be perpendicular to the arrangement direction of the multiple evaporation modules 2. During operation, the tank 21 is under negative pressure, with a pressure value ranging from -1 kPa to -95 kPa. The material of the negative pressure tank 21 is not limited to carbon steel, 304 stainless steel, 316L stainless steel, titanium, aluminum alloy, etc.

[0027] Reference Figure 1 and Figure 3 Each tank 21 has a first connecting pipe 5 connecting its top to the steam inlet pipe 3. The first connecting pipe 5 facilitates the extraction of steam from the tank 21 in each evaporation module 2 to the steam compressor 1 for pressurization and heating. Each tank 21 has an inlet pipe 6 at its upper end for supplying liquid, which connects to an external raw material storage tank for the corresponding liquid. A membrane assembly 23 is installed inside the tank 21, and multiple membrane assemblies 23 are installed within each tank 21. These multiple membrane assemblies 23 are spaced apart along the length of the corresponding tank 21, and are connected to the inlet pipe 6. The liquid entering the corresponding tank 21 is used to flow onto the outer wall of multiple membrane groups 23; each tank 21 is connected to the steam outlet pipe 4 by a second connecting pipe 7, which is used to introduce the steam output by the steam compressor 1 into each membrane group 23 in the corresponding tank 21; the condensate collection mechanism 24 is used to collect the condensate of multiple membrane groups 23 in the corresponding tank 21; each tank 21 is connected to a fresh steam inlet pipe 45 for connecting to an external fresh steam source, which is used to introduce high-temperature fresh steam into the corresponding tank 21.

[0028] During operation, various types of liquid materials are fed into different tanks 21 through multiple inlet pipes 6. The liquid materials then flow onto the outer walls of corresponding membrane film groups 23. Under gravity, the liquid materials flow downwards along the outer walls of the membrane film groups 23 to form a liquid film. A fresh steam inlet pipe 45 introduces high-temperature fresh steam into the corresponding tanks 21 to evaporate the liquid materials. The steam evaporating from the outer walls of the membrane film groups 23 enters the steam inlet pipe 3 through the corresponding first connecting pipe 5, and is then drawn into the steam compressor 1 for compression. The steam compressor 1 pressurizes and heats the steam, which is then distributed through the steam outlet pipe 4. The steam is fed into the second connecting pipe 7, which then delivers the high-temperature steam to multiple membrane groups 23 within the corresponding tank 21. Here, the high-temperature steam in the membrane groups 23 exchanges heat with the liquid on the outer wall of the membrane groups 23, causing evaporation. Under negative pressure, the liquid evaporates rapidly, and this cycle continues, resulting in a concentrated liquid at the bottom of the tank 21. Condensate is collected at the condensate collection mechanism 24. Using a single low-temperature steam compressor 1 to connect multiple evaporation modules 2 in parallel can meet the simultaneous treatment needs of various types of wastewater in actual wastewater treatment, thus helping to control energy consumption. Furthermore, by effectively utilizing the evaporated steam, it is unnecessary to introduce a large amount of external high-temperature steam through the fresh steam inlet pipe 45 for heat exchange with the liquid, saving costs to a certain extent.

[0029] Reference Figure 1 and Figure 3 To facilitate sufficient heat exchange between the liquid feed and the high-temperature steam, each group of membranes 23 includes multiple polymer membranes 231 arranged sequentially along a horizontal direction. Specifically, the arrangement direction of the multiple polymer membranes 231 is parallel to the length direction of the tank body 21. The polymer membranes 231 are cuboid or cubic in shape, and their thickness is 0.01mm-1mm. The polymer membrane 231 material is resistant to high temperature and corrosion, and has a high thermal conductivity. Its material is not limited to one or more of the following molecular materials: PP, PE, PTFE, FEP, PEEK, PA, PS, graphite, silicon carbide, aluminum, silver, and titanium. Among them, PP refers to polypropylene; PE refers to polyethylene; PTFE refers to polytetrafluoroethylene; FEP refers to fluorinated ethylene propylene copolymer; PEEK refers to polyether ether ketone; PA refers to polyamide; and PS refers to polystyrene.

[0030] Reference Figure 4 and Figure 5Each polymer film 231 has a water outlet 38 on its lower sidewall, and a water guide plate 39 is fixedly installed on the lower inner sidewall of each polymer film 231. The water guide plate 39 is aligned with and connected to the water outlet 38 in the corresponding polymer film 231. The axial direction of the water guide plate 39 is parallel to the arrangement direction of the multiple polymer films 231. The water guide plates 39 in the multiple polymer films 231 are pressed together in sequence to form an internal horizontal sealed channel to facilitate the flow of condensate. Specifically, the water guide plate 39 is provided with multiple channels for discharging condensate so that the condensate in the polymer film 231 can enter the water outlet 38 through the channels on the water guide plate 39. The sealed channel formed by the multiple water guide plates 39 is used to connect with the corresponding condensate collection mechanism 24.

[0031] Reference Figure 4 and Figure 5 The inner wall of the polymer film 231 is provided with water channels 40, which include a dotted water channel 401, a wave water channel 402, and a straight water channel 403 arranged sequentially from top to bottom. The dotted water channel 401 consists of multiple circular thermoplastic dots. One end of the straight water channel 403 is connected to the wave water channel 402, and the other end is connected to the flow channel on the corresponding water guide plate 39 inside the polymer film 231. The polymer film 231 is integrally hot-pressed, which helps to ensure the formation of the dotted water channel 401, wave water channel 402, and straight water channel 403 inside the film.

[0032] Since the high-temperature steam entering the polymer film 231 is in a gaseous state, it is easier for the high-temperature steam to accumulate under the action of multiple wave channels 401. The accumulated high-temperature steam falls and flows along the wave-shaped flow channel formed by multiple wave channels 402 to multiple straight channels 403. Then it flows from the straight channels 403 to the water guide plate 39, and enters the corresponding condensate collection mechanism 24 from the outlet 38 through the water guide plate 39. The arrangement of the channels 40 can uniformly cool and guide the high-temperature steam entering the polymer film 231, which helps to improve the evaporation effect.

[0033] Reference Figure 3 and Figure 4 To facilitate the uniform distribution of the liquid entering through the inlet pipe 6 to the outer walls of multiple polymer films 231, each evaporation module 2 also includes a water equalization mechanism 22. The water equalization mechanism 22 is located inside the corresponding tank 21 and corresponds one-to-one with the film group 23. The water equalization mechanism 22 is located above the corresponding film group 23. The water equalization mechanism 22 helps to evenly distribute the liquid entering through the inlet pipe 6 to the outer wall of the corresponding film group 23, so that the liquid can flow from top to bottom in a film-like manner along the outer wall of the film group 23.

[0034] Reference Figure 3 and Figure 4Specifically, the water distribution mechanism 22 includes a distribution box 221 and a water distribution strip 222. The distribution box 221 is fixedly installed at the upper end inside the tank 21. Further, the cross-section of the distribution box 221 is rectangular. The liquid inlet pipe 6 is fixedly inserted into the tank 21. Each distribution box 221 has a first branch pipe (not shown in the figure) distributed above it. The first branch pipe is connected to the liquid inlet pipe 6, which helps the liquid in the liquid inlet pipe 6 to flow into multiple distribution boxes 221. Multiple water passage holes 33 are opened on the bottom wall of the distribution box 221. Multiple water distribution strips 222 are provided, and the arrangement direction of the multiple water distribution strips 222 is parallel to the arrangement direction of the multiple polymer films 231. The length direction of the multiple water distribution strips 222 is perpendicular to the arrangement direction of the multiple water distribution strips 222. The multiple water distribution strips 222 are connected in series and squeezed to be fixed below the distribution box 221 inside the tank body 21. The distribution box 221 covers the water inlet surface formed by the multiple water distribution strips 222. In the specific implementation process, a certain gap is left between the bottom wall of the distribution box 221 and the upper surface of the multiple water distribution strips 222, and a rectangular frame is fixed between the two. The rectangular frame seals the gap between the distribution box 221 and the multiple water distribution strips 222, so that the liquid will not flow to other positions inside the tank body 21.

[0035] Reference Figure 3 and Figure 4 A clamping space is formed between adjacent water equalization strips 222, and the clamping space corresponds one-to-one with the polymer film 231. The upper end of the polymer film 231 is located in the corresponding clamping space. The adjacent water equalization strips 222 clamp the upper end of the polymer film 231 between them. The water equalization strip 222 has a plurality of water equalization holes 34, and the arrangement direction of the plurality of water equalization holes 34 is parallel to the length direction of the corresponding water equalization strip 222.

[0036] When the liquid in the inlet pipe 6 enters the distribution box 221, the liquid in the distribution box 221 flows evenly through multiple water holes 33 to the inlet level formed by multiple water distribution strips 222 below. Then, the liquid flows through the water distribution holes 34 on the multiple water distribution strips 222 to the outer wall of the corresponding polymer film 231, which helps to make the liquid flow evenly from top to bottom along the outer wall of the multiple polymer films 231 to form a liquid film for evaporation, thus helping to improve the evaporation effect of the liquid.

[0037] Reference Figure 4 and Figure 5The water distribution strip 222 is made of inorganic or organic materials, and the material is not limited to PP, PE, PS, PA, PSE, PTFE, iron, stainless steel, aluminum, titanium, gold, silver, fiberglass, graphite, silicon carbide, etc.; it has the advantages of good corrosion resistance, low cost, readily available materials, and high practicality. Furthermore, the water distribution strip 222 can be composed of two water distribution half-strips spliced ​​together by male and female snap fasteners, or it can be a complete rectangular strip. In the embodiments of this application, the form of the water distribution strip 222 is not limited. The water distribution strip 222 is composed of two water distribution half strips. On the side of the two water distribution half strips that are close to each other, multiple partition plates are integrally formed and abut against each other. Multiple water distribution holes 34 are formed by the abutting of the partition plates. The water distribution half strips can also be assembled by splicing multiple strips. This type of water distribution strip 222 is easy to assemble and disassemble and can be spliced ​​arbitrarily as needed. The water distribution strip 222 that adopts the form of a complete rectangular strip has multiple holes opened on the rectangular strip to form multiple water distribution holes 34. This type of water distribution strip 222 does not require splicing and is easy to install.

[0038] Reference Figure 3 and Figure 4 To facilitate the uniform introduction of the high-temperature steam output from the steam compressor 1 into the multiple polymer films 231 within the tank 21, each evaporation module 2 also includes a gas equalization mechanism 27. The gas equalization mechanism 27 corresponds one-to-one with the film group 23 and includes multiple gas equalization strips 271. Each gas equalization strip 271 corresponds one-to-one with the polymer film 231 of the corresponding film group 23. Steam inlets are provided on the sidewalls of the polymer films 231, and the gas equalization strips 271 are installed within the steam inlets of the corresponding polymer films 231, extending vertically. Adjacent air equalization strips 271 are separated by a polymer film 231, forming an air inlet plane. A connecting flange 44 is fixedly connected to the air inlet plane, covering the air inlet plane to form a sealed space. The connecting flange 44 is connected to the second connecting pipe 7 of the corresponding tank body 21. Specifically, multiple air equalization strips 271 are connected and pressed together in the tank body 21 by multiple screws, and adjacent air equalization strips 271 are pressed together. Each air equalization strip 271 has multiple air equalization holes 35, and the arrangement direction of the multiple air equalization holes 35 is parallel to the length direction of the air equalization strip 271. Furthermore, the material and structure of the air equalization strip 271 are the same as those of the water equalization strip 222.

[0039] In use, the high-temperature steam output by the steam compressor 1 enters the air inlet plane through the second connecting pipe 7 and the corresponding connecting flange 44, and then enters each polymer film 231 evenly along the air distribution holes 35 on the multiple air distribution strips 271 to ensure the evaporation effect.

[0040] Reference Figure 3 , Figure 4 and Figure 5To facilitate the collection of condensate, the condensate collection mechanism 24 includes a water collector 241, a condensate collection pipe 242, and a condensate collection tank 243. The water collector 241 corresponds one-to-one with the membrane group 23 and is located below the multiple polymer membranes 231 of the corresponding membrane group 23. Specifically, the water collector 241 includes an abutment ring and a connecting pipe. The abutment ring is annular, and the axis of the connecting pipe is perpendicular to the axis of the abutment ring. The connecting pipe is connected to the inside of the abutment ring. The abutment ring is clamped between the water guide plates 39 in any two adjacent polymer membranes 231 in the corresponding membrane group 23. Optimally, the abutment ring is clamped between the water guide plates 39 in the two middle polymer membranes 231 of the membrane group 23, so that the condensate can flow into the water collector 241 and be discharged from the sealed channel formed by the multiple water guide plates 39. The axial direction of the abutment ring is parallel to the axial direction of the multiple water guide plates 39, so that the multiple water guide plates 39 can be connected to the water collector 241, realizing the connection between the water outlet 38 and the corresponding water collector 241; specifically, the multiple water guide plates 39 and the abutment ring can be connected and tightened together by screws.

[0041] Reference Figure 3 and Figure 5 The end of the connecting pipe furthest from the abutment ring is connected to the condensate collection pipe 242, which is fixedly installed on the corresponding tank 21. The condensate collection pipe 242 is located below multiple polymer films 231, and the condensate collection tank 243 is located outside the tank 21. The condensate collection pipe 242 is connected to the condensate collection tank 243, thus facilitating the transport of condensate through the condensate collection pipe 242 to the condensate collection tank 243. Furthermore, the condensate collection tanks 243 of the multiple evaporation modules 2 are each connected to the same vacuum pump group via vacuum connecting pipes. Each vacuum connecting pipe is equipped with a throttle valve, and the vacuum pump group is used to provide a vacuum environment for the tanks 21 of the multiple evaporation modules 2. By using the vacuum pump group to connect multiple evaporation modules 2 in parallel, the evaporation vacuum degree for different wastewater treatments can be met through the throttle valves in actual wastewater treatment.

[0042] The high-temperature steam inside the polymer film 231 exchanges heat with the liquid material on the outer surface of the polymer film 231, causing the high-temperature steam inside the polymer film 231 to condense into condensate. Then, the condensate enters the water collector 241 from the water guide plate 39 along the water channel 40, and then enters the condensate collection pipe 242 through the water collector 241, and then enters the condensate collection tank 243 from the condensate collection pipe 242.

[0043] Reference Figure 3To facilitate the full utilization of the condensate temperature, each evaporation module 2 also includes a first heat exchanger 26. The condensate collection tank 243 is connected to the corresponding first heat exchanger 26 through a pipe. The condensate in the condensate collection tank 243 exchanges heat with the liquid entering the corresponding inlet pipe 6 through the first heat exchanger 26, which helps to utilize the waste heat of the condensate to heat the liquid entering the inlet pipe 6, thus helping to save costs. The condensate after heat exchange is stored in a storage tank for recycling.

[0044] Reference Figure 1 and Figure 3 Each of the first connecting pipes 5 and the second connecting pipes 7 is equipped with a control valve 8, which allows for the inspection and maintenance of the independent evaporation module 2 without stopping the machine, without affecting the operation of other evaporation modules 2.

[0045] Reference Figure 3 The bottom of the tank 21 is connected to a concentrate discharge pipe 9, and a concentrate pump body 10 is installed on the concentrate discharge pipe 9. A concentration sensor (not shown in the figure) for detecting the concentration of the concentrate is installed at the bottom of the tank 21. Both the concentration sensor and the concentrate pump body 10 are wirelessly connected to an external control platform. The concentrate discharge pipe 9 is used to connect to an external corresponding concentrate buffer tank. By adding a reagent to the concentrate buffer tank and then filtering the liquid in the concentrate buffer tank, solid and liquid are separated. The separated filter residue is collected separately and outsourced for processing, while the separated filtrate is transported to the corresponding raw liquid storage tank, where it undergoes heat exchange again before entering the tank 21, thereby ensuring the evaporation effect.

[0046] When the concentration detection value received by the external control platform is less than the preset value, the concentrate pump 10 is turned off; when the concentration detection value received by the external control platform is greater than the preset value, the concentrate at the bottom of the tank 21 is pumped into the concentrate discharge pipe 9 through the concentrate pump 10 and discharged from the tank 21, and then enters the corresponding concentrate buffer tank for subsequent processing.

[0047] Reference Figure 1 and Figure 3 A circulating liquid pipe 36 is provided between the bottom of each tank 21 and the top of the corresponding tank 21. One end of the circulating liquid pipe 36 is connected to the bottom of the corresponding tank 21, and the other end extends into the corresponding tank 21. A second branch pipe (not shown in the figure) is distributed above each distribution box 221. The second branch pipe is connected to the circulating liquid pipe 36. A circulating liquid pump body 37 is installed on the circulating liquid pipe 36.

[0048] The concentrated liquid at the bottom of the tank 21 is pumped by the circulating liquid pump 37 into the circulating liquid pipeline 36 and then enters the distribution box 221 for evaporation and concentration, thereby forming a high-concentration concentrated liquid at the bottom of the tank 21, which helps to ensure the concentration effect.

[0049] Reference Figure 1 and Figure 3 To facilitate sufficient heating of the incoming liquid, each evaporation module 2 also includes a second heat exchanger 28. A steam delivery pipe 43 is connected between the upper end of the tank 21 and the second heat exchanger 28. A steam extraction pump is installed on the steam delivery pipe 43. The steam output from the steam delivery pipe 43 exchanges heat with the liquid entering the corresponding inlet pipe 6 through the second heat exchanger 28, thereby helping to use the heat of the steam to heat the liquid entering the inlet pipe 6, so that the liquid can evaporate quickly after entering the tank 21.

[0050] Reference Figure 3 Specifically, both the first heat exchanger 26 and the second heat exchanger 28 are plate heat exchangers. The raw liquid is filtered by a filter press and then enters the corresponding external raw liquid storage tank. The raw liquid in the storage tank is pumped into the first heat exchanger 26 and the second heat exchanger 28 respectively for heat exchange, and then enters the liquid inlet pipe 6 so that it can enter the tank 21 for heating and evaporation.

[0051] Reference Figure 6 and Figure 7 An impeller 11 is rotatably installed inside the outlet of the concentrate discharge pipe 9 near the bottom of the tank 21. The rotation axis of the impeller 11 is parallel to the height direction of the tank 21. A shaft is coaxially fixed on the impeller 11, and a scraper 12 is fixedly sleeved on the shaft. The scraper 12 includes a fixed rod 121 and a sliding rod 122. The fixed rod 121 is fixedly sleeved on the shaft, and the length direction of the fixed rod 121 is perpendicular to the rotation axis of the impeller 11. The sliding rod 122 is sleeved on the end of the fixed rod 121 away from the impeller 11. The bottom wall of the sliding rod 122 is provided with bristles, which abut against the bottom wall of the corresponding tank 21.

[0052] When the concentrate pump body 10 draws the concentrate from the concentrate discharge pipe 9 into the tank 21, the concentrate flowing through the outlet of the concentrate discharge pipe 9 impacts the impeller 11, causing the impeller 11 to rotate. During the rotation of the impeller 11, the shaft rotates, causing the fixed rod 121 and the sliding rod 122 to rotate along the axis of the impeller 11. This allows the bristles to brush the dirt on the bottom wall of the tank 21 and agitate the deposits, so that the dirt and deposits on the bottom wall of the tank 21 can be drawn out of the tank 21 along with the concentrate, which helps to prevent scale buildup inside the tank 21.

[0053] Reference Figure 6 and Figure 7The sliding rod 122 is slidably sleeved on the corresponding fixed rod 121. The sliding direction of the sliding rod 122 is parallel to the length direction of the corresponding fixed rod 121. The fixed rod 121 is provided with an elastic element for pushing the sliding rod 122 to slide away from the fixed rod 121. In this embodiment, the elastic element includes a push spring 41, which is located at the end of the fixed rod 121. One end of the push spring 41 is fixed to the end of the fixed rod 121, and the other end is fixed inside the sliding rod 122. In other embodiments, the push spring 41 can be replaced with an elastic sheet.

[0054] Reference Figure 6 and Figure 7 A first connecting rope 13 is fixed to one end of the sliding rod 122 near the fixed rod 121. A drum 14 is fixed inside the concentrate discharge pipe 9. The shaft rotates through the drum 14. The end of the first connecting rope 13 away from the sliding rod 122 is fixed on the drum 14. When the impeller 11 rotates due to the impact of the concentrate, the first connecting rope 13 gradually winds around the drum 14. To ensure that the impeller 11 can reverse and reset, a torsion spring is movably sleeved on the shaft. One end of the torsion spring is fixed on the drum 14, and the other end is fixed on the fixed rod 121. When the torsion spring is in its natural state, the push spring 41 is in its natural state.

[0055] Reference Figure 6 and Figure 7 A fixing plate 15 is installed inside the tank body 21. Fixing rods 121 are located below multiple polymer films 231. Multiple water passage holes 16 are provided on the fixing plate 15. A sliding plate 17 is slidably attached to the lower surface of the fixing plate 15. The sliding direction of the sliding plate 17 is parallel to the length direction of the tank body 21. Multiple telescopic rods 42 are fixed between the sliding plate 17 and the inner wall of the tank body 21. The extension and retraction directions of the telescopic rods 42 are parallel to the sliding direction of the sliding plate 17, and the telescopic rods 42 guide the sliding of the sliding plate 17. Multiple adjusting holes 18 are provided on the sliding plate 17, each corresponding to one of the water passage holes 16. A return spring 19 is fixed between the sliding plate 17 and the inner wall of the tank body 21, each corresponding to one of the telescopic rods 42. The return spring 19 is movably sleeved on the corresponding telescopic rod 42. When the return spring 19 is in its natural state, the adjusting hole 18 is aligned with the corresponding water passage hole 16.

[0056] Reference Figure 6 and Figure 7A sliding rack 20 is slidably disposed on the inner wall of the tank body 21. The sliding rack 20 is located below the sliding plate 17, at the end of the sliding plate 17 away from the telescopic rod 42. The sliding direction of the sliding rack 20 is perpendicular to the rotation axis of the impeller 11, and further, the sliding direction of the sliding rack 20 is perpendicular to the sliding direction of the sliding plate 17. A sliding groove is formed on the inner wall of the tank body 21 to slide with the sliding rack 20. A friction element is disposed between the sliding rack 20 and the bottom wall of the sliding groove. The resistance of the friction element is greater than the elastic force of the return spring 19. Specifically, the friction element includes a first rubber layer and a second rubber layer. The first rubber layer is fixed on the side of the sliding rack 20 near the sliding groove, and the second rubber layer is fixed on the bottom wall of the sliding groove. The first rubber layer and the second rubber layer are in contact, and the friction between the first rubber layer and the second rubber layer is greater than the elastic force of the return spring 19. In other embodiments, the first rubber layer and the second rubber layer can also be replaced by a first silicone layer and a second silicone layer.

[0057] Reference Figure 6 and Figure 7 A second connecting rope 31 is fixed between the sliding rack 20 and the sliding plate 17. A guide pulley 30 is fixed on the inner wall of the tank body 21. The guide pulley 30 is located above the sliding rack 20. The second connecting rope 31 between the sliding rack 20 and the sliding plate 17 is slidably connected to the guide pulley 30. The second connecting rope 31 is used to pull the sliding plate 17 to move so that the adjusting hole 18 is away from the corresponding water passage hole 16. When the reset spring 19 is in the natural state, the second connecting rope 31 is in the tensioned state.

[0058] Reference Figure 6 and Figure 7 The end of the sliding rod 122 is fixed with a tooth block 32 for pushing the sliding rack 20 to slide. When the pushing spring 41 is in the natural state, the tooth block 32 is disengaged from the sliding rack 20, and the distance from the end of the tooth block 32 away from the fixed rod 121 to the shaft is greater than the distance from the shaft to the side of the sliding rack 20 near the shaft.

[0059] When the concentration of the concentrate at the bottom of tank 21 is less than or equal to the preset value, the concentrate pump 10 is in the off state and the circulating liquid pump 37 is in the working state. At this time, the reset spring 19 is in the natural state, so that the adjusting hole 18 is aligned with the corresponding water passage hole 33. The concentrate on the outer wall of the polymer film 231 can flow to the bottom wall of tank 21 through the water passage hole 33 on the fixing plate 15 and be filtered through the water passage hole 33 on the fixing plate 15. The concentrate pump 10 draws the concentrate at the bottom of tank 21 into the circulating liquid pipeline 36 and sends it back into the corresponding tank 21 to realize the circulation evaporation of the liquid, which helps to improve the evaporation effect.

[0060] When the concentration of the concentrate at the bottom of tank 21 exceeds a preset value, the concentrate pump 10 is in operation, and the circulating fluid pump 37 is in operation. The concentrate then exits tank 21 through the concentrate discharge pipe 9, causing it to impact the impeller 11 and drive it to rotate. At this time, the force on the impeller 11 is greater than the torsion force of the torsion spring and the elastic force of the push spring 41. This causes the impeller 11 to drive the shaft and fixed rod 121 to rotate. The fixed rod 121 then drives the sliding rod 122 to rotate. During the rotation of the sliding rod 122, the first connecting rope 13 winds along the drum 14, thereby pulling the sliding rod 122. Approaching the fixed rod 121, the compression push spring 41 is compressed. When the sliding rod 122 moves to the sliding rack 20 for the first time, the tooth block 32 on the sliding rod 122 meshes with the sliding rack 20 and pushes the sliding rack 20 to move along the sliding groove. This causes the sliding rack 20 to pull the sliding plate 17 away from the telescopic rod 42 through the second connecting rope 31, causing the adjusting hole 18 to be misaligned with the corresponding water passage hole 33. At this time, the liquid flowing down the polymer film 231 can only accumulate above the fixed plate 15 and will not be discharged from the tank 21 along with the concentrate at the bottom of the tank 21, thus ensuring the concentration effect of the tank 21 and realizing the discharge of concentrate without stopping the machine. Next, the toothed block 32 disengages from the sliding rack 20. Under the resistance of the friction element, the sliding rack 20 stops moving. As the fixed rod 121 and the sliding rod 122 continue to rotate, the sliding rod 122 gradually approaches the fixed rod 121. The bristles at the bottom of the sliding rod 122 brush the bottom wall of the tank 21 to facilitate the discharge of dirt and deposits along with the concentrate from the tank 21. This continues until the push spring 41 can no longer be compressed, and the fixed rod 121 and the sliding rod 122 stop rotating. The spring force of the push spring 41, the torsion spring torque, and the driving force of the concentrate impacting the impeller 11 are balanced.

[0061] After the concentrate is completely discharged, the impeller 11 is no longer under force. The compressed push spring 41 drives the sliding rod 122 to slide away from the fixed rod 121. At the same time, under the action of the torsion spring, the fixed rod 121, the sliding rod 122 and the impeller 11 rotate in opposite directions to reset. After rotating to the required number of turns, the tooth block 32 on the sliding rod 122 pushes the sliding rack 20 to move in the opposite direction, reducing the tension of the sliding rack 20 on the second connecting rope 31. Under the action of the reset spring 19, the sliding plate 17 is reset to move closer to the telescopic rod 42, and the water passage 33 is opened again so that the concentrate evaporated from the polymer film 231 can enter the bottom of the tank 21 through the water passage 33.

[0062] The implementation principle of this application embodiment is as follows: During operation, various types of liquid materials are input into different tanks 21 through multiple inlet pipes 6. Then, the liquid materials flow through the first branch pipe to multiple distribution boxes 221 in the corresponding tank 21. The liquid materials in the distribution boxes 221 quickly flow evenly through multiple water holes 33 to the water distribution strips 222 below. Then, the liquid materials flow evenly through the water distribution holes 34 on the multiple water distribution strips 222 to the outer wall of multiple polymer films 231. The fresh steam inlet pipe 45 introduces high-temperature fresh steam into the corresponding tank 21 to evaporate the liquid materials. The steam compressor 1 extracts the steam evaporated from the outer wall of the film inside the multiple tanks 21 through the corresponding first connecting pipe 5 and steam inlet pipe 3, then pressurizes and heats it. Then, the high-temperature steam is delivered to the air inlet plane in each tank 21 through the steam outlet pipe 4 and the second connecting pipe 7. Then, the high-temperature steam enters the multiple polymer films 231 through the air equalization holes 35 on the multiple air equalization strips 271 in the corresponding tanks 21. The high-temperature steam in the polymer film 231 exchanges heat with the liquid on the outer wall of the polymer film 231 to evaporate, thereby reducing the amount of fresh steam introduced from the outside.

[0063] Next, the concentrated liquid on the surface of the polymer film 231 flows to the bottom of the tank 21 through the water passage 16 on the fixed plate 15. At the bottom of the tank 21, the concentrated liquid is pumped back into the distribution box 221 for evaporation via the circulating liquid pump 37 and circulating liquid pipe 36. The concentration of the concentrated liquid at the bottom of the tank 21 is detected by a concentration sensor. When the detected concentration value is greater than a preset value, the concentrated liquid is output through the concentrated liquid discharge pipe 9. The concentrated liquid impacts the impeller 11 inside the concentrated liquid discharge pipe 9, causing the impeller 11 to drive the shaft, fixed rod 121, and sliding rod 122 to rotate. During the rotation of the sliding rod 122, the first connecting rope 13 winds along the drum 14, thus pulling the sliding rod 122 closer to the fixed rod 121. When the sliding rod 122 initially moves to the sliding rack 20, the teeth on the sliding rod 122... Block 32 engages with sliding rack 20 and pushes sliding rack 20 to move along sliding groove. At this time, sliding rack 20 pulls sliding plate 17 away from telescopic rod 42 through second connecting rope 31, so that adjusting hole 18 and corresponding water passage hole 33 are misaligned. At this time, the liquid flowing down on polymer film 231 can only accumulate on fixed plate 15 and will not be discharged from tank 21 with the concentrate at the bottom of tank 21, ensuring the concentration of discharged concentrate and realizing non-stop discharge of concentrate. Then, block 32 disengages from sliding rack 20. As fixed rod 121 and sliding rod 122 continue to rotate, sliding rod 122 gradually approaches fixed rod 121. The bristles at the bottom of sliding rod 122 brush the bottom wall of tank 21 to facilitate the discharge of dirt and deposits with concentrate from tank 21 until pushing spring 41 can no longer be compressed and fixed rod 121 and sliding rod 122 stop rotating.

[0064] The concentrate discharged from the concentrate discharge pipe 9 enters the external concentrate buffer tank. By adding reagents to the concentrate buffer tank and then filtering the liquid in the concentrate buffer tank, solid and liquid are separated. The separated filter residue is collected separately and outsourced for processing, while the separated filtrate is transported to the corresponding raw liquid storage tank, where it undergoes heat exchange again before entering the tank body 21, thereby ensuring the evaporation effect.

[0065] The condensate within the polymer film 231 is collected in the collector 241 via the water channel 40 and the guide plate 39, and then enters the condensate collection tank 243 through the condensate collection pipe 242. The condensate exchanges heat with the liquid entering the inlet pipe 6 through the first heat exchanger 26. Simultaneously, a portion of high-temperature fresh steam is transported to the second heat exchanger 28 through the steam delivery pipe 43 to exchange heat with the liquid entering the inlet pipe 6. This cycle continues. Using a single low-temperature steam compressor 1 to connect multiple evaporation modules 2 in parallel can meet the needs of simultaneously treating various types of wastewater in actual wastewater treatment, helping to control energy consumption. Furthermore, by effectively utilizing the secondary steam and waste heat from the condensate, there is no need to introduce large amounts of external high-temperature steam for heat exchange with the liquid, saving costs to a certain extent.

[0066] This application also discloses a multi-module thin-film evaporation process. The multi-module thin-film evaporation process uses the aforementioned multi-module thin-film evaporator and includes the following steps: Step 1: The liquid is fed into the corresponding tank 21 through the inlet pipe 6; Step 2: Next, the liquid enters multiple distribution boxes 221 and flows through multiple water holes 33 on the distribution box 221 to the water distribution strip 222 below. The liquid flows evenly through the water distribution holes 34 on the water distribution strip 222 to the outer wall of multiple polymer films 231. Fresh steam inlet pipe 45 introduces fresh steam from the outside into the corresponding tank 21 to evaporate the liquid on the outer wall of the polymer film 231. Step 3: The steam evaporated from the outer wall of the film is pressurized and heated by the steam compressor 1, the steam inlet pipe 3 and the first connecting pipe 5 and then transported to multiple second connecting pipes 7. The steam then enters multiple polymer films 231 evenly through the gas equalization mechanism 27. The steam in the polymer film 231 exchanges heat with the liquid on the outer wall of the polymer film 231 and evaporates. Step 4: Then, the concentrate is obtained at the bottom wall of the tank 21. The concentrate at the bottom of the tank 21 enters the corresponding multiple uniform distribution boxes 221 again through the circulating liquid pump 37 and the circulating liquid pipe 36 for evaporation. The concentration of the concentrate at the bottom of the tank 21 is detected by the concentration sensor. When the concentration detection value is greater than the preset value, the concentrate is pumped from the concentrate discharge pipe 9 to the external concentrate buffer tank by the concentrate pump 10. The concentrate buffer tank is filled with a reagent and then the liquid in the concentrate buffer tank is filtered to separate the solid and liquid. The separated filter residue is collected separately and outsourced for processing, while the separated filtrate is sent to the corresponding original liquid storage tank and heat-exchanged again before entering the corresponding tank 21. Step 5: The condensate in the polymer film 231 enters the condensate collection tank 243 through the water collector 241 and the condensate collection pipe 242, and then exchanges heat with the original liquid entering the liquid inlet pipe 6 through the corresponding first heat exchanger 26.

[0067] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A multi-module thin-film evaporator, characterized in that: The system includes a steam compressor (1) and multiple evaporation modules (2). The input end of the steam compressor (1) is connected to a steam inlet pipe (3), and the output end of the steam compressor (1) is connected to a steam outlet pipe (4). Each evaporation module (2) includes a tank (21), a film assembly (23), and a condensate collection mechanism (24). Each evaporation module (2) has multiple film assemblies (23), which are horizontally spaced within the corresponding tank (21). Each tank (21) is connected to an inlet pipe (6) for feeding liquid. The inlet pipe (6) delivers... The feed liquid is used to flow to the outer wall of the corresponding multiple membrane groups (23). Each tank (21) is connected to the steam inlet pipe (3) by a first connecting pipe (5), and each tank (21) is connected to the steam outlet pipe (4) by a second connecting pipe (7). The second connecting pipe (7) is used to introduce the steam output from the steam compressor (1) into the corresponding multiple membrane groups (23). The condensate collection mechanism (24) is used to collect the condensate in the multiple membrane groups (23) in the corresponding tank (21). The tank (21) is connected to a fresh steam inlet pipe (45) for connecting to an external fresh steam source. The tank body (21) has a concentrate discharge pipe (9) connected to its bottom. A concentrate pump body (10) is installed on the concentrate discharge pipe (9). The concentrate discharge pipe (9) is used to connect with an external concentrate buffer tank. An impeller (11) is rotatably installed in the pipe opening near the bottom of the tank body (21). A scraper (12) is connected to the impeller (11). The scraper (12) is provided with bristles that abut against the bottom wall of the corresponding tank body (21). The scraper (12) includes a fixed rod (121) connected to the impeller (11) and a sliding rod (121) slidably sleeved on the fixed rod (121). 22), the bristles are arranged on the sliding rod (122), the fixed rod (121) is provided with an elastic element for pushing the sliding rod (122) to slide away from the fixed rod (121), the sliding rod (122) is provided with a first connecting rope (13), the concentrated liquid discharge pipe (9) is provided with a drum (14), the drum (14) is coaxial with the impeller (11), the end of the first connecting rope (13) away from the sliding rod (122) is provided on the drum (14), when the impeller (11) is impacted and rotated by the concentrated liquid, the first connecting rope (13) is wound on the drum (14);A fixing plate (15) is provided inside the tank (21). The fixing plate (15) is located below multiple polymer films (231) inside the corresponding tank (21). Multiple water passage holes (16) are provided on the fixing plate (15). A sliding plate (17) is slidably provided on the surface of the fixing plate (15). Multiple adjusting holes (18) are provided on the sliding plate (17). The adjusting holes (18) correspond one-to-one with the water passage holes (16). A return spring (19) is provided between the sliding plate (17) and the inner wall of the tank (21). When the return spring (19) is in its natural state, the adjusting holes (18) are aligned with the corresponding water passage holes (16). A sliding rack (20) is slidably provided on the inner wall of the tank (21). The sliding direction of the sliding rack (20) is perpendicular to the rotation axis of the impeller (11). A friction element is provided between the sliding rack (20) and the inner wall of the tank (21). The resistance of the friction element is greater than the elastic force of the return spring (19). A second connecting rope (31) is provided between the sliding rack (20) and the sliding plate (17). The second connecting rope (31) is used to pull the sliding plate (17) to move so that the adjusting hole (18) is away from the corresponding water passage hole (16). The end of the sliding rod (122) is provided with a tooth block (32) for pushing the sliding rack (20) to slide.

2. The multi-module thin-film evaporator according to claim 1, characterized in that: A control valve (8) is installed on each of the first connecting pipe (5) and the second connecting pipe (7).

3. A multi-module thin-film evaporator according to claim 1, characterized in that: The bottom wall of the tank (21) is equipped with a concentration sensor for detecting the concentration of the concentrate. Both the concentration sensor and the concentrate pump (10) are wirelessly connected to an external control platform.

4. A multi-module thin-film evaporator according to claim 3, characterized in that: Each group of film groups (23) includes multiple polymer films (231) arranged sequentially in the tank (21) along the horizontal direction. Each evaporation module (2) also includes a water equalization mechanism (22), which corresponds one-to-one with the film group (23). The water equalization mechanism (22) is located above the corresponding film group (23). Each water equalization mechanism (22) includes a distribution box (221) and a water equalization strip (222) arranged in the tank (21). The liquid in the liquid inlet pipe (6) flows into the tank and then into the water. The water distribution box (221) is located in a plurality of uniform distribution boxes (221) in the corresponding tank (21). The bottom wall of the uniform distribution box (221) is provided with a plurality of water passage holes (33). The uniform distribution box (221) is located above the water distribution strip (222). There are a plurality of water distribution strips (222). The arrangement direction of the plurality of water distribution strips (222) is parallel to the arrangement direction of the plurality of polymer films (231). The upper end of the polymer film (231) is sandwiched between adjacent water distribution strips (222). The water distribution strip (222) has a plurality of water distribution holes (34).

5. A multi-module thin-film evaporator according to claim 4, characterized in that: Each of the evaporation modules (2) further includes a gas equalization mechanism (27), which corresponds one-to-one with the film group (23). The gas equalization mechanism (27) includes a plurality of gas equalization strips (271), which correspond one-to-one with the polymer film (231). The sidewall of the polymer film (231) is provided with a steam inlet. The gas equalization strip (271) is located in the steam inlet of the corresponding polymer film (231). Adjacent gas equalization strips (271) abut against each other with a polymer film (231) to form an air inlet plane. The air inlet plane is used to communicate with the corresponding second connecting pipe (7). The gas equalization strip (271) has a plurality of gas equalization holes (35).

6. A multi-module thin-film evaporator according to claim 1, characterized in that: The condensate collection mechanism (24) includes a water collector (241), a condensate collection pipe (242), and a condensate collection tank (243). The water collector (241) corresponds one-to-one with the membrane group (23). The lower end of the membrane group (23) inside the tank (21) is connected to the corresponding water collector (241). The condensate collection pipe (242) is installed on the tank (21). The water collector (241) is connected to the condensate collection pipe (242). The condensate collection tank (243) is located outside the tank (21). The condensate collection pipe (242) is connected to the condensate collection tank (243).

7. A multi-module thin-film evaporator according to claim 6, characterized in that: Each of the evaporation modules (2) further includes a first heat exchanger (26), and the condensate collection tank (243) is connected to the corresponding first heat exchanger (26). The first heat exchanger (26) is used to exchange heat between the condensate in the condensate collection tank (243) and the feed liquid entering the corresponding liquid inlet pipe (6).

8. A multi-module thin-film evaporator according to claim 5, characterized in that: A circulating liquid pipe (36) is provided between the bottom of each tank (21) and the top of the corresponding tank (21). The circulating liquid pipe (36) is used to transport the concentrated liquid at the bottom of the tank (21) to multiple uniform distribution boxes (221). A circulating liquid pump body (37) is installed on the circulating liquid pipe (36).

9. A multi-module thin-film evaporation process, using the multi-module thin-film evaporator as described in claim 8, characterized in that, Includes the following steps: Step 1: The liquid is fed into the corresponding tank (21) through the inlet pipe (6); Step 2: Next, the liquid material enters multiple distribution boxes (221) and flows through multiple water holes (33) on the distribution box (221) to the water distribution strip (222) below. The liquid material flows evenly through the water distribution holes (34) on the multiple water distribution strip (222) to the outer wall of multiple polymer films (231). Fresh steam from the outside is introduced into the corresponding tank (21) through the fresh steam inlet pipe (45) to evaporate the liquid material on the outer wall of the polymer film (231). Step 3: The steam evaporated from the outer wall of the polymer film (231) is pressurized and heated by the steam compressor (1), steam inlet pipe (3) and first connecting pipe (5) and transported to multiple second connecting pipes (7). Then the steam is evenly introduced into multiple polymer films (231) through the gas equalization mechanism (27). The steam in the polymer film (231) exchanges heat with the liquid on the outer wall of the polymer film (231) for evaporation. Step 4: Then, the concentrate is obtained at the bottom wall of the tank (21). The concentrate at the bottom of the tank (21) is re-entered into the corresponding multiple uniform distribution boxes (221) for evaporation through the circulating liquid pump (37) and the circulating liquid pipe (36). The concentration of the concentrate at the bottom of the tank (21) is detected by the concentration sensor at the bottom of the tank (21). When the concentration detection value is greater than the preset value, the concentrate is transported from the concentrate discharge pipe (9) to the external concentrate buffer tank through the concentrate pump (10). By adding the reagent to the external concentrate buffer tank and then filtering the liquid in the concentrate buffer tank, the solid and liquid are separated. The separated filter residue is collected separately and outsourced for processing, while the separated filtrate is transported to the corresponding original liquid storage tank and heat exchanged again before entering the corresponding tank (21). Step 5: The condensate in the polymer film (231) is collected by the condensate collection mechanism (24).

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