Vapor-liquid washing device of MVR (Mechanical Vapor Recompression) spraying system

Abstract

The utility model discloses a vapor-liquid washing device of an MVR (Mechanical Vapor Recompression) spraying system, which comprises a falling film evaporator and a separator, the falling film evaporator pumps materials into the interior through a boundary pump, the materials are circularly concentrated through the falling film evaporator, and the materials are conveyed to the next working procedure from the interior of the falling film evaporator through a falling film circulating pump after reaching the standard. The falling-film evaporator decompresses steam through a pressure reducing valve and conveys the steam into the falling-film evaporator, the steam exchanges heat with materials to form distilled water, and the distilled water is discharged into a distilled water tank through a pipeline. The device has the beneficial effects that water vapor is in countercurrent contact with spraying liquid, so that the steam washing effect is improved; the steam washing tower adopts a circulating spraying mode, so that the water supply amount of spraying is effectively reduced; the liquid level transmitter is adopted, so that the internal liquid amount can be detected on line; the conductivity meter is adopted, the conductivity index of the spraying liquid can be detected on line, the salt content of the spraying liquid is represented on the side face, and the liquid with the high salt content is prevented from blocking a nozzle on the spraying head.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery production waste liquid treatment technology, and in particular to an MVR spray system vapor-liquid scrubbing device. Background Technology

[0002] MVR technology refers to Mechanical Vapor Recompression, which compresses the low-temperature secondary steam generated by the system through a steam compressor, increasing its temperature, pressure, and enthalpy. The steam then enters a heat exchanger for heat exchange and condensation, making full use of the latent heat of the steam to heat the materials.

[0003] In the lithium battery production process, high-salt sodium sulfate wastewater is generated. This wastewater undergoes evaporation and crystallization through an evaporation system, concentrating the sodium sulfate in the wastewater. The material circulates and evaporates from top to bottom in a falling film evaporator. The resulting secondary steam undergoes vapor-liquid separation in a falling film separator. The secondary steam flows through the middle of the steam scrubbing tower, where it encounters spray water distributed at the top of the tower. Passing through baffles, the high-temperature condensate effectively washes the secondary steam, removing entrained salts and other impurities, thus purifying the secondary steam. This ensures that the secondary steam entering the steam compressor is pure and clean, preventing salt entrainment and particle agglomeration that could cause physical damage to the impeller. It also prevents organic matter from adhering to the impeller, affecting dynamic balance and consequently the normal operation of the compressor. The resulting spray water circulates within the tower. After circulation, it is monitored online by conductivity and effectively discharged into the falling film separator. The spray water is then recovered and continues to participate in the evaporation cycle, recovering heat from the condensate and ensuring system thermal balance.

[0004] However, in the process of implementing the utility model technical solution in the embodiments of this application, the applicant discovered that the above-mentioned technology has at least the following technical problems:

[0005] Traditional MVR spray washing devices do not effectively detect the salt content in the tower, cannot determine the effective concentration of the spray liquid in the tower, and cannot determine when to regularly discharge the spray liquid for effective replacement. If the spray liquid concentration is too low, the spray water volume will be large and wasteful. If the cumulative concentration of the spray liquid is too high, the spray nozzle will be blocked, the spray pressure will be reduced, and the cleaning ability will be weakened. Utility Model Content

[0006] This application provides an MVR spray system vapor-liquid scrubbing device where water vapor and spray liquid come into countercurrent contact, maximizing the gas-liquid contact area and improving the scrubbing effect. The scrubbing tower uses a circulating spray method, effectively reducing the amount of water supplied for spraying. A level transmitter is used to detect the internal liquid volume online, control the soft water valve to replenish water, and maintain a stable liquid level in the scrubbing tower. A conductivity meter is used to detect the conductivity of the spray liquid online, indirectly indicating the salt content of the spray liquid, preventing high-salt liquid from clogging the nozzles on the spray head, and improving the scrubbing effect.

[0007] This application provides an MVR spray system vapor-liquid scrubbing device, including a falling film evaporator and a separator. The falling film evaporator uses a boundary pump to pump material into its interior. The material is circulated and concentrated within the falling film evaporator. After reaching the required standard, the material is transported from the falling film evaporator to the next process via a falling film circulation pump. The falling film evaporator uses a pressure reducing valve to reduce steam pressure and transport it into its interior. The steam exchanges heat with the material to form distilled water. The distilled water is discharged into a distilled water tank through a pipeline. The distilled water in the distilled water tank is pumped out to a preheating unit by a distilled water pump. The secondary steam generated inside the falling film evaporator is separated. The liquid is discharged into a steam scrubbing tower, which is equipped with a conductivity meter, a level transmitter, and a spray water self-flow discharge valve. One side of the steam scrubbing tower is connected to soft water via a pipe and a soft water valve. The steam scrubbing tower has a structure that is narrower at the top and wider at the bottom. The lower end of the steam scrubbing tower is a gas-liquid separation section, and the upper end is a spray water scrubbing section. The bottom of the steam scrubbing tower is connected to a spray circulation pump and a separator via a pipe. The spray circulation pump draws the liquid from the bottom of the steam scrubbing tower to the spray head at the top of the steam scrubbing tower for spraying. The steam scrubbing tower at the spray head is equipped with a baffle plate. The top of the steam scrubbing tower is connected to a steam compressor via a pipe, and the other end of the steam compressor is connected to a falling film evaporator.

[0008] The number of spray heads is 3-5, and the spray heads are located directly above the baffles. The baffles are arranged alternately and are connected and fixed to the steam washing tower by welding.

[0009] The secondary steam is connected to the middle of the steam scrubbing tower through a pipeline. The secondary steam rises from the middle and comes into contact with the liquid sprayed from top to bottom. The secondary steam and the sprayed liquid are in countercurrent contact.

[0010] When the conductivity of the conductivity meter exceeds 50,000 μS / cm, stop spraying, turn off the spray circulation pump, and open the spray water gravity discharge valve.

[0011] The level transmitter monitors the amount of liquid inside the gas scrubbing tower. When the liquid level inside the gas scrubbing tower reaches the low limit, it closes the spray water self-flow discharge valve and opens the soft water valve. When the set liquid level is reached, it closes the soft water valve and opens the spray circulation pump.

[0012] The conductivity meter controls the operating power of the spray circulation pump by changing its conductivity.

[0013] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0014] 1. Water vapor and sprayed liquid come into countercurrent contact, maximizing the gas-liquid contact area and improving the steam washing effect.

[0015] 2. The steam scrubbing tower adopts a circulating spray method, which effectively reduces the amount of water supplied for spraying. The spray liquid from one wash can continue to participate in the spraying cycle. When the concentration of the spray liquid exceeds the standard, it can be characterized online. In this way, the amount of water to be replenished can be controlled by the spraying circulation pump, thereby reducing the amount of water to be sprayed at one time.

[0016] 3. The steam scrubbing tower is equipped with a level transmitter, which can detect the internal liquid volume online, control the soft water valve to replenish water, and maintain a stable liquid level inside the steam scrubbing tower.

[0017] 4. A conductivity meter is used to detect the conductivity of the spray liquid online, which indirectly indicates the salt content of the spray liquid. This facilitates timely replacement of the spray liquid, prevents high-salt liquid from clogging the nozzles on the spray head, and improves the steam washing effect. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a vapor-liquid scrubbing device for an MVR spray system according to this utility model;

[0019] Figure 2 This is a schematic diagram of the structure of the steam washing tower in this utility model. Detailed Implementation

[0020] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods. Example

[0021] A vapor-liquid scrubbing device for an MVR spray system includes a falling film evaporator 4 and a separator 9. The falling film evaporator 4 uses a boundary pump to pump material 1 into its interior. The material 1 is circulated and concentrated within the falling film evaporator 4. After reaching the required standard, the material 1 is transported from the falling film evaporator 4 to the next process via a falling film circulation pump 8. The falling film evaporator 4 uses a pressure reducing valve 3 to reduce the pressure of steam 2 and transport it into its interior. The steam 2 exchanges heat with the material 1 to form distilled water. The distilled water is discharged through a pipe into a distilled water tank 7. The distilled water in the distilled water tank 7 is pumped out to a preheating unit 5 by a distilled water pump 6. The secondary steam generated inside the falling film evaporator 4 is discharged into a steam scrubbing tower 11 after passing through the separator 9. The steam scrubbing tower 11... Equipped with a conductivity meter 113, a level transmitter 112, and a spray water self-flow unloading valve 114, the steam scrubbing tower 11 is connected to soft water 12 via a pipeline and a soft water valve on one side. The steam scrubbing tower 11 has a structure that is narrower at the top and wider at the bottom. The lower end of the steam scrubbing tower 11 is a gas-liquid separation section, and the upper end is a spray water scrubbing section. The bottom of the steam scrubbing tower 11 is connected to a spray circulation pump 10 and a separator 9 via a pipeline. The spray circulation pump 10 draws the liquid from the bottom of the steam scrubbing tower 11 to the spray head 801 at the top of the steam scrubbing tower 11 for spraying. A baffle plate 111 is provided on the steam scrubbing tower 11 at the spray head 801. The top of the steam scrubbing tower 11 is connected to a steam compressor 13 via a pipeline, and the other end of the steam compressor 13 is connected to a falling film evaporator 4.

[0022] There are 3-5 spray heads 801, which are located directly above the baffles 111. The baffles 111 are arranged alternately and are connected and fixed to the steam scrubbing tower 11 by welding. The secondary steam is connected to the middle of the steam scrubbing tower 11 through a pipe. The secondary steam comes into contact with the liquid sprayed from top to bottom from the middle. The secondary steam and the sprayed liquid are in countercurrent contact.

[0023] The technical solutions described in the embodiments of this application have at least the following technical effects or advantages:

[0024] The use of baffles 111 can effectively increase the contact time between vapor and liquid, thereby effectively improving the washing effect of vapor and liquid. Because the gas is relatively light, it contacts the liquid from bottom to top, which can maximize the contact area and further improve the washing effect. Example

[0025] A vapor-liquid scrubbing device for an MVR spray system, wherein when the conductivity of the conductivity meter 113 exceeds 50000 μS / cm, spraying is stopped, the spray circulation pump 10 is shut down, and the spray water gravity discharge valve 114 is opened; the liquid level transmitter 112 monitors the liquid volume inside the gas scrubbing tower 11, and when the liquid level inside the gas scrubbing tower reaches the low limit, the spray water gravity discharge valve 114 is closed and the soft water valve is opened; when the set liquid level is reached, the soft water valve is closed and the spray circulation pump 10 is turned on; the conductivity meter 113 controls the operating power of the spray circulation pump 10 through changes in conductivity.

[0026] The technical solutions described in the embodiments of this application have at least the following technical effects or advantages:

[0027] The conductivity meter 113 and the level transmitter 112 can detect not only the internal liquid level but also the salt content of the liquid. By controlling the soft water valve to replenish water and to change the water in time, the internal steam washing can be stabilized and the spray head 801 can be prevented from clogging.

[0028] The sprayed body fluid can be drained to separator 9 to continue participating in the evaporation cycle, recovering heat and salt, thus ensuring the system's recovery rate.

[0029] Working principle: Material 1 is pumped from the boundary area to the falling film evaporator 4, where it circulates and is continuously concentrated. Material 1 that meets the standards is then distributed to the next process via a circulation pump. Steam 2 is depressurized by the pressure reducing valve 3 and enters the falling film evaporator 4. Steam 2 exchanges heat with material 1 to form distilled water, which is discharged to the distilled water tank 7 and pumped out of the preheating unit 5 by the distilled water pump 6. The secondary steam generated by the falling film evaporation enters the steam scrubbing tower 11, where it comes into countercurrent contact with the spray water to thoroughly wash away the salts or impurities carried in the steam 2, purifying the gas and ensuring the purity of the secondary steam. This prevents impurities from affecting the stable operation of the steam compressor 13. The steam scrubbing tower 11 then delivers the washed secondary steam to the steam compressor 13. The steam compressor 13 mechanically acts on the steam 2, converting mechanical energy into heat energy, providing the temperature and pressure for the secondary steam, and then reheating the falling film evaporator 4 to recover heat. The scrubbing liquid in the steam scrubber 11 passes through the baffle plate 111 at the top, allowing it to contact the upward-facing vapor phase at the bottom for thorough washing. The liquid then flows by gravity and converges at the bottom of the steam scrubber 11. The spray circulation pump 10 continuously draws liquid for spraying and circulates the liquid. When the conductivity meter 113 installed in the steam scrubber 11 detects a conductivity value exceeding the specified value (design value: 50000 μS / cm), spraying and the spray circulation pump 10 are stopped. The inlet and outlet valves of the spray circulation pump 10 are closed, and the spray water gravity discharge valve 114 is opened, discharging the high-salt scrubbing liquid into the separator 9 to continue participating in the evaporation cycle. When the liquid level in the steam scrubber 11 reaches the low limit and liquid discharge is complete, the spray water gravity discharge valve 114 is closed, and the soft water valve is opened to replenish water to the steam scrubber 11. When the set liquid level is reached, water replenishment is complete, and the soft water valve is closed. At this time, the inlet valve of the spray circulation pump 10 can be opened, the outlet valve of the pneumatic spray circulation pump 10 can be opened, and the spray circulation pump 10 can perform material 1 circulation spraying.

[0030] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0031] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A MVR spray system vapor-liquid scrubbing apparatus comprising a falling film evaporator and a separator, characterized in that, The falling film evaporator is pumped into the unit by a boundary pump. The material is then circulated and concentrated within the evaporator. Once the material meets the required standards, it is transferred from the evaporator to the next process via a falling film circulation pump. The evaporator uses a pressure-reducing valve to depressurize the steam before it is introduced into the unit. The steam exchanges heat with the material to form distilled water. This distilled water is piped into a distilled water tank, and then pumped out to the preheating unit. The secondary steam generated inside the falling film evaporator passes through a separator and is then discharged into a steam scrubbing tower, which is equipped with a conductivity meter. The steam scrubbing tower includes instruments, a level transmitter, and a spray water self-flow unloading valve. One side of the steam scrubbing tower is connected to soft water via a pipeline and a soft water valve. The steam scrubbing tower has a structure that is narrower at the top and wider at the bottom. The lower end of the steam scrubbing tower is a gas-liquid separation section, and the upper end is a spray water scrubbing section. The bottom of the steam scrubbing tower is connected to a spray circulation pump and a separator via a pipeline. The spray circulation pump draws the liquid from the bottom of the steam scrubbing tower to the spray head at the top of the steam scrubbing tower for spraying. The steam scrubbing tower is equipped with baffles at the spray head. The top of the steam scrubbing tower is connected to a steam compressor via a pipeline, and the other end of the steam compressor is connected to a falling film evaporator.

2. A MVR spray system vapor-liquid scrubbing apparatus as claimed in claim 1, wherein, The number of spray heads is 3-5, and the spray heads are located directly above the baffles. The baffles are arranged alternately and are connected and fixed to the steam washing tower by welding.

3. A MVR spray system vapor-liquid scrubbing apparatus as claimed in claim 1, wherein, The secondary steam is connected to the middle of the steam scrubbing tower through a pipeline. The secondary steam rises from the middle and comes into contact with the liquid sprayed from top to bottom. The secondary steam and the sprayed liquid are in countercurrent contact.

4. A MVR spray system vapor-liquid scrubbing apparatus as claimed in claim 1, wherein, When the conductivity of the conductivity meter exceeds 50,000 μS / cm, stop spraying, turn off the spray circulation pump, and open the spray water gravity discharge valve.

5. A MVR spray system vapor-liquid scrubbing apparatus as claimed in claim 1, wherein, The level transmitter monitors the amount of liquid inside the gas scrubbing tower. When the liquid level inside the gas scrubbing tower reaches the low limit, it closes the spray water self-flow discharge valve and opens the soft water valve. When the set liquid level is reached, it closes the soft water valve and turns on the spray circulation pump.

6. A MVR spray system vapor-liquid scrubbing apparatus as claimed in claim 1, wherein, The conductivity meter controls the operating power of the spray circulation pump by changing its conductivity.

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