Integrated MVR evaporation system

Abstract

The utility model relates to an integrated MVR (mechanical vapor recompression) evaporation system which is applied to the technical field of wastewater evaporation and concentration treatment. A feed port of the I-section falling film evaporator on the shell is connected with a discharge port of the circulating pump, and a discharge port of the I-section falling film evaporator on the shell is connected with a feed port of the circulating pump; a feed port of the climbing film evaporator section II on the shell is connected with a discharge port of the circulating pump; a discharge port of the second-section climbing film evaporator on the shell is connected with a feed port of the crystallization chamber; a discharge port of the crystallization chamber is connected with a feed port of the second-section climbing film evaporator on the shell; a steam outlet of the crystallization chamber is connected with a steam inlet of the steam compressor; a steam outlet of the steam compressor is connected with a steam inlet in the shell; and a feed port of the discharge pump is connected with a discharge port of the crystallization chamber. The I-section falling-film evaporator and the II-section rising-film evaporator are integrated in the shell to form an integrated structure, so that the size of equipment can be reduced, the occupied area can be saved, and the problem of heat loss caused by an overlong pipeline is solved.

Description

Technical Field

[0001] This application relates to the field of industrial wastewater evaporation and concentration treatment technology, and in particular to an integrated MVR evaporation system. Background Technology

[0002] Mechanical vapor recompression (MVR) is a new type of highly efficient and energy-saving evaporation technology. MVR technology is widely used in wastewater treatment in industries such as chemical, pharmaceutical and food processing. MVR technology makes full use of the secondary steam generated by the evaporation system when treating industrial wastewater. The secondary steam is transformed into high-quality regenerated steam by the forced compression of the compressor. The regenerated steam then provides a heat source for the evaporator, thereby reducing the demand for external energy. Finally, a high-concentration concentrate, namely crystal slurry, is obtained from the evaporator. The crystal slurry can be recycled in industrial production.

[0003] Currently, most evaporators used in MVR evaporation systems are rising film evaporators and falling film evaporators. Combining rising film and falling film evaporators is a relatively ideal choice, which can improve the evaporation and concentration treatment effect of the feed liquid and make the final product recovery effect better. For example, the prior art with announcement number CN207575801U and patent name "Dual-stage MVR evaporation equipment", and the prior art with announcement number CN205634945U and patent name "Mobile dyeing and printing wastewater concentration treatment device" both use rising film evaporators and falling film evaporators connected in series through pipes in the MVR evaporation system. However, this method of connecting rising film evaporators and falling film evaporators in series through pipes will increase the size of the equipment, and if the pipes are long, there will also be problems of heat loss and energy consumption. Utility Model Content

[0004] To address the shortcomings of current MVR evaporation systems, which connect rising film evaporators and falling film evaporators in series via pipes, resulting in increased equipment size and issues of heat loss and energy consumption due to long pipes, this application provides an integrated MVR evaporation system.

[0005] This application provides an integrated MVR evaporation system, which adopts the following technical solution:

[0006] An integrated MVR evaporation system includes,

[0007] Feed pump;

[0008] A circulating pump, wherein the outlet of the feed pump is connected to the inlet of the circulating pump;

[0009] An evaporator, comprising a shell and a first-stage falling film evaporator and a second-stage rising film evaporator disposed within the shell, wherein the inlet of the first-stage falling film evaporator on the shell is connected to the outlet of a circulating pump, and the outlet of the first-stage falling film evaporator on the shell is connected to the inlet of a circulating pump.

[0010] The inlet of the second-stage rising film evaporator is connected to the outlet of the circulating pump on the shell.

[0011] The outlet of the crystallization chamber and the inlet of the second-stage rising film evaporator on the shell are connected.

[0012] An electric valve is installed on the pipeline connecting the outlet of the circulating pump and the inlet of the first-stage falling film evaporator on the shell. An electric valve is installed on the pipeline connecting the outlet of the circulating pump and the inlet of the second-stage rising film evaporator on the shell.

[0013] The steam compressor is connected to the steam outlet of the crystallization chamber and the steam inlet of the steam compressor, and the steam outlet of the steam compressor is connected to the steam inlet on the casing.

[0014] A discharge pump, the inlet of which is connected to the outlet of the crystallization chamber.

[0015] By adopting the above technical solution, after the raw material liquid enters the MVR evaporation system from the feed pump, it first passes through the first-stage falling film evaporator for circulation and concentration, and then enters the second-stage rising film evaporator for further circulation and concentration, until the concentrated liquid reaches the standard and is discharged from the discharge pump in the form of crystal slurry. During this process, the steam generated in the crystallization chamber is forcibly compressed by the steam compressor to transform into high-quality regenerated steam, which then provides a heat source for the evaporator, thereby reducing the MVR evaporation system's demand for external energy. The solution in this application integrates the first-stage falling film evaporator and the second-stage rising film evaporator into a single shell, meaning that the first-stage falling film evaporator and the second-stage rising film evaporator share a single shell. This not only reduces the equipment size and saves space, but also solves the problem of heat loss and energy consumption caused by excessively long connecting pipelines.

[0016] Optionally, it also includes a first-stage plate preheater, with the inlet of the first-stage plate preheater connected to the outlet of the feed pump, and the outlet of the first-stage plate preheater connected to the inlet of the circulating pump; the steam outlet on the shell is connected to the heat medium inlet of the first-stage plate preheater.

[0017] By adopting the above technical solution, the steam delivered from the evaporator can be recovered and reused in the first-stage plate preheater. The steam is used as a heat medium to preheat the raw material liquid, which can make full use of the steam energy produced by the system and improve the concentration treatment effect of the raw material liquid after entering the evaporator.

[0018] Optionally, a vacuum pump is also included, the inlet of which is connected to the heat medium outlet of the first-stage plate preheater.

[0019] By adopting the above technical solution, the vacuum pump is used to pump out and discharge the steam energy that has been used up by the system.

[0020] Optionally, it also includes a second-stage plate preheater, the inlet of which is connected to the outlet of the first-stage plate preheater, and the outlet of which is connected to the inlet of the circulating pump; the condensate outlet on the shell is connected to the heat medium inlet of the second-stage plate preheater.

[0021] By adopting the above technical solution, the superheated condensate from the evaporator is recycled to the second-stage plate preheater. The superheated condensate is used as a heat medium to further preheat the raw material liquid. Based on the first-stage plate preheater, the second-stage plate preheater further heats the raw material liquid, making the concentration treatment effect of the raw material liquid better after entering the evaporator. Secondly, it makes full use of the superheated condensate energy produced by the MVR evaporation system, which is both energy-saving and efficient.

[0022] Optionally, a condensate pump is also included, the inlet of which is connected to the heat medium outlet of the second-stage plate preheater.

[0023] By adopting the above technical solution, the condensate pump is used to pump out and discharge the superheated condensate energy that has been used by the system.

[0024] Optionally, it also includes a condensate tank, the inlet of which is connected to the heat medium outlet of the second-stage plate preheater, and the outlet of which is connected to the inlet of the condensate pump.

[0025] By adopting the above technical solution, after the superheated condensate is used as a heat medium in the second-stage plate preheater, it can be temporarily stored in the condensate tank and cooled down naturally for a period of time before being discharged from the condensate pump, thereby improving the overall safety of the MVR evaporation system.

[0026] Optionally, it also includes a flash tank, the inlet of which is connected to the condensate outlet on the shell, and the outlet of which is connected to the heat medium inlet of the second-stage plate preheater.

[0027] By adopting the above technical solution, the superheated condensate delivered from the evaporator first enters the flash tank and then enters the second-stage plate preheater as a heat medium. The flash tank provides space for rapid vapor-liquid separation of the superheated condensate, and the generated steam is recovered and reused. The separated superheated condensate continues to enter the second-stage plate preheater.

[0028] Optionally, the steam outlet of the flash tank is connected to the steam inlet of the steam compressor.

[0029] By adopting the above technical solution, the steam generated by the flash tank can be recovered and reused in the evaporator, making full use of the steam energy produced by the system, which is both energy-saving and efficient.

[0030] In summary, this application includes the following beneficial technical effects:

[0031] 1. After the feed liquid enters the MVR evaporation system from the feed pump, it is first preheated by the first stage plate preheater and the second stage plate preheater, and then circulated and concentrated by the first stage falling film evaporator and the second stage rising film evaporator until the concentrated liquid reaches the standard and is discharged from the discharge pump in the form of crystal slurry. During this process, the steam generated in the crystallization chamber is forcibly compressed by the steam compressor and converted into high-quality regenerated steam. The regenerated steam then provides a heat source for the first stage falling film evaporator and the second stage rising film evaporator, thereby reducing the MVR evaporation system's demand for external energy.

[0032] 2. The technical solution of this application integrates the I-stage falling film evaporator and the II-stage rising film evaporator into a shell to form an evaporator. That is, the I-stage falling film evaporator and the II-stage rising film evaporator share a shell, which is an integrated structure. This not only reduces the size of the equipment and saves the space occupied by the equipment, but also solves the problem of heat loss and energy consumption caused by excessively long connecting pipes. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of an integrated MVR evaporation system in an embodiment of this application.

[0034] Reference numerals: 1. Feed pump; 2. Circulation pump; 3. Evaporator; 31. Shell; 32. Stage I falling film evaporator; 33. Stage II rising film evaporator; 4. Crystallization chamber; 5. Electric valve one; 6. Electric valve two; 7. Steam compressor; 8. Discharge pump; 9. Stage I plate preheater; 10. Vacuum pump; 11. Stage II plate preheater; 12. Condensate pump; 13. Condensate tank; 14. Flash tank. Detailed Implementation

[0035] The following is in conjunction with the appendix Figure 1 This application will be described in further detail.

[0036] This application discloses an integrated MVR evaporation system, referring to... Figure 1The evaporator 3 in the integrated MVR evaporation system integrates the first-stage falling film evaporator 32 and the second-stage rising film evaporator 33 into the shell 31, forming an integrated structure. This not only reduces the equipment size and saves space, but also solves the problems of heat loss and energy consumption caused by excessively long connecting pipes. The evaporator 3 of this application is suitable for materials with low viscosity in the high-concentration range. Specifically, the first-stage falling film evaporator 32 and the second-stage rising film evaporator 33 are integrated into the shell 31, and baffles are provided at both ends of the shell 31, making the first-stage falling film evaporator 32 and the second-stage rising film evaporator 33 independent structures. This allows the concentrate to be circulated and concentrated in the first-stage falling film evaporator 32 before entering the second-stage rising film evaporator 33 for further circulation and concentration, ultimately obtaining a higher quality crystal slurry product.

[0037] Reference Figure 1 A feed pump 1 is installed at the initial end of the MVR evaporation system. The raw material liquid to be processed enters the system from the feed pump 1. The outlet of the feed pump 1 is connected to the inlet of the first-stage plate preheater 9. The outlet of the first-stage plate preheater 9 is connected to the inlet of the second-stage plate preheater 11. The outlet of the second-stage plate preheater 11 is connected to the inlet of the circulation pump 2. The outlet of the first-stage falling film evaporator 32 on the shell 31 is also connected to the inlet of the circulation pump 2. The outlet of the circulation pump 2 is connected to the inlet of the first-stage falling film evaporator 32 on the shell 31.

[0038] For the first-stage plate preheater 9, the heat medium inlet of the first-stage plate preheater 9 is connected to the steam outlet on the shell 31 of the evaporator 3. The steam delivered from the evaporator 3 is recycled and enters the first-stage plate preheater 9 to preheat the feed liquid. The heat medium outlet of the first-stage plate preheater 9 is connected to the inlet of the vacuum pump 10, which ultimately discharges the steam from the system. For the second-stage plate preheater 11, the heat medium inlet of the second-stage plate preheater 11 is connected to the condensate outlet on the shell 31 of the evaporator 3. The superheated condensate delivered from the evaporator 3 is recycled and enters the second-stage plate preheater 11 to perform secondary preheating of the feed liquid. This increases the overall temperature of the feed liquid before it enters the evaporator 3, thereby improving the concentration effect of the concentrate in the evaporator 3. The heat medium outlet of the second-stage plate preheater 11 is connected to the inlet of the condensate pump 12, which ultimately discharges the condensate from the system.

[0039] It should be noted that a condensate tank 13 is installed between the second-stage plate preheater 11 and the condensate pump 12. The heat medium outlet of the second-stage plate preheater 11 is connected to the inlet of the condensate tank 13, while the outlet of the condensate tank 13 is connected to the inlet of the condensate pump 12. The superheated condensate discharged from the first-stage plate preheater 9 is temporarily stored in the condensate tank 13 for a period of time before being discharged from the condensate pump 12. The superheated condensate is cooled down naturally in the condensate tank 13, which makes the discharge of condensate at a lower temperature safer.

[0040] Reference Figure 1 After the raw material liquid is preheated by the first-stage plate preheater 9 and the second-stage plate preheater 11, it is forcibly fed from top to bottom into the first-stage falling film evaporator 32 by the circulating pump 2. In the first-stage falling film evaporator 32, it undergoes circulation and concentration treatment before entering the second-stage rising film evaporator 33. The inlet of the second-stage rising film evaporator 33 on the shell 31 is connected to the outlet of the circulating pump 2. It should be noted that an electric valve 5 is installed on the pipeline connecting the outlet of the circulating pump 2 and the inlet of the first-stage falling film evaporator 32 on the shell 31, and an electric valve 6 is installed on the pipeline connecting the outlet of the circulating pump 2 and the inlet of the second-stage rising film evaporator 33 on the shell 31. When the concentrated liquid undergoes circulation treatment in the first-stage falling film evaporator 32, electric valve 5 is open and electric valve 6 is closed. When the concentrated liquid enters the second-stage rising film evaporator 33 after treatment in the first-stage falling film evaporator 32, the electric valve 5 is closed. With electric valve 5 in the closed state and electric valve 6 in the open state, the concentrated liquid enters the second-stage rising film evaporator 33 from bottom to top for further concentration and circulation. The outlet of the second-stage rising film evaporator 33 on the shell 31 is connected to the inlet of the crystallization chamber 4, and the outlet of the crystallization chamber 4 is connected to the inlet of the second-stage rising film evaporator 33 on the shell 31. The crystallization chamber 4 can continuously perform vapor-liquid separation on the concentrated liquid circulating in the second-stage rising film evaporator 33. The resulting concentrated liquid re-enters the second-stage rising film evaporator 33 for further concentration, while the generated steam is discharged from the steam outlet of the crystallization chamber 4 and recycled back to the evaporator 3.

[0041] A discharge pump 8 is installed at the end of the MVR evaporation system. The inlet of the discharge pump 8 is connected to the outlet of the crystallization chamber 4. When the concentrate reaches the standard, it is discharged from the discharge pump 8 in the form of crystal slurry.

[0042] Reference Figure 1In this application, the steam used in the evaporator 3 of the MVR evaporation system comes from the crystallization chamber 4 and the flash tank 14. The steam outlet of the crystallization chamber 4 is connected to the steam inlet of the steam compressor 7, and the steam outlet of the steam compressor 7 is connected to the steam inlet on the shell 31 of the evaporator 3. In this way, the steam generated in the crystallization chamber 4 is forcibly compressed by the steam compressor 7 and converted into high-quality regenerated steam. The regenerated steam then provides a heat source for the evaporator 3, thereby reducing the demand of the MVR evaporation system for external energy. The steam delivered from the evaporator 3 is then recycled to the first-stage plate preheater 9. The entire MVR evaporation system is highly efficient and energy-saving. The flash tank 14 is located between the heat medium inlet of the second-stage plate preheater 11 and the condensate outlet on the shell 31 of the evaporator 3. The inlet of the flash tank 14 is connected to the condensate outlet on the shell 31 of the evaporator 3, while the outlet of the flash tank 14 is connected to the heat medium inlet of the second-stage plate preheater 11. The steam outlet of the flash tank 14 is connected to the steam inlet of the steam compressor 7. After being discharged from the evaporator 3, the superheated condensate first enters the flash tank 14 and then enters the second-stage plate preheater 11. The flash tank 14 provides space for rapid vapor-liquid separation of the superheated condensate. The generated steam is recycled back to the evaporator 3, while the separated superheated condensate continues to be used in the second-stage plate preheater 11, improving the efficiency and energy saving of the entire MVR evaporation system.

[0043] The implementation principle of an integrated MVR evaporation system according to an embodiment of this application is as follows: After the raw material liquid enters the MVR evaporation system from the feed pump 1, it is first preheated by the first-stage plate preheater 9 and the second-stage plate preheater 11, and then circulated and concentrated by the first-stage falling film evaporator 32 and the second-stage rising film evaporator 33 until the concentrated liquid reaches the standard and is discharged from the discharge pump 8 in the form of crystal slurry. During this process, the steam generated by the crystallization chamber 4 and the flash tank 14 is forcibly compressed by the steam compressor 7 and transformed into high-quality regenerated steam. The regenerated steam then provides a heat source for the first-stage falling film evaporator 32 and the second-stage rising film evaporator 33, thereby reducing the demand of the MVR evaporation system for external energy. The technical solution of this application integrates the first-stage falling film evaporator 32 and the second-stage rising film evaporator 33 into the shell 31 to form the evaporator 3. That is, the first-stage falling film evaporator 32 and the second-stage rising film evaporator 33 share a shell 31, which is an integrated structure. This not only reduces the size of the equipment and saves the space occupied by the equipment, but also solves the problem of heat loss and energy consumption caused by excessively long connecting pipes.

[0044] 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. An integrated MVR evaporation system, characterized in that, Comprising, a feed pump (1); a circulating pump (2), the outlet of the feed pump (1) and the inlet of the circulating pump (2) are connected; an evaporator (3), the evaporator (3) comprises a shell (31) and an I-section falling film evaporator (32) and a II-section rising film evaporator (33) arranged in the shell (31), the inlet of the I-section falling film evaporator (32) on the shell (31) and the outlet of the circulating pump (2) are connected, the outlet of the I-section falling film evaporator (32) on the shell (31) and the inlet of the circulating pump (2) are connected; the inlet of the II-section rising film evaporator (33) on the shell (31) and the outlet of the circulating pump (2) are connected; a crystallization chamber (4), the outlet of the II-section rising film evaporator (33) on the shell (31) and the inlet of the crystallization chamber (4) are connected, the outlet of the crystallization chamber (4) and the inlet of the II-section rising film evaporator (33) on the shell (31) are connected; an electric valve one (5) is arranged on the pipeline connecting the outlet of the circulating pump (2) and the inlet of the I-section falling film evaporator (32) on the shell (31), an electric valve two (6) is arranged on the pipeline connecting the outlet of the circulating pump (2) and the inlet of the II-section rising film evaporator (33) on the shell (31); a steam compressor (7), the steam outlet of the crystallization chamber (4) and the steam inlet of the steam compressor (7) are connected, the steam outlet of the steam compressor (7) and the steam inlet on the shell (31) are connected; a discharge pump (8), the inlet of the discharge pump (8) and the outlet of the crystallization chamber (4) are connected.

2. The integrated MVR evaporation system of claim 1, wherein, Further comprising an I-section plate preheater (9), the inlet of the I-section plate preheater (9) and the outlet of the feed pump (1) are connected, the outlet of the I-section plate preheater (9) and the inlet of the circulating pump (2) are connected; the steam outlet on the shell (31) and the heat medium inlet of the I-section plate preheater (9) are connected.

3. The integrated MVR evaporation system of claim 2, wherein, Further comprising a vacuum pump (10), the inlet of the vacuum pump (10) and the heat medium outlet of the I-section plate preheater (9) are connected.

4. The integrated MVR evaporation system of claim 2, wherein, Further comprising a II-section plate preheater (11), the inlet of the II-section plate preheater (11) and the outlet of the I-section plate preheater (9) are connected, the outlet of the II-section plate preheater (11) and the inlet of the circulating pump (2) are connected; the condensate water outlet on the shell (31) and the heat medium inlet of the II-section plate preheater (11) are connected.

5. The integrated MVR evaporation system of claim 4, wherein, Further comprising a condensate water pump (12), the inlet of the condensate water pump (12) and the heat medium outlet of the II-section plate preheater (11) are connected.

6. The integrated MVR evaporation system of claim 5, wherein, Further comprising a condensate water tank (13), the inlet of the condensate water tank (13) and the heat medium outlet of the II-section plate preheater (11) are connected, the outlet of the condensate water tank (13) and the inlet of the condensate water pump (12) are connected.

7. The integrated MVR evaporation system of claim 4, wherein, Further comprising a flash tank (14), the inlet of the flash tank (14) and the condensate water outlet on the shell (31) are connected, the outlet of the flash tank (14) and the heat medium inlet of the II-section plate preheater (11) are connected; 8. The integrated MVR evaporation system of claim 7, wherein, the steam outlet of the flash tank (14) and the steam inlet of the steam compressor (7) are connected.

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