CN218810520U

CN218810520U - MVR evaporation system for cooperatively recycling preserved szechuan pickle wastewater

Info

Publication number: CN218810520U
Application number: CN202222923889.3U
Authority: CN
Inventors: 易伟; 王建军; 唐文通; 徐登平; 徐茂; 郭建容; 宋春林
Original assignee: Dianjiang County Small And Medium Enterprise Public Service Center; Southwest University
Current assignee: Dianjiang County Small And Medium Enterprise Public Service Center; Southwest University
Priority date: 2022-11-03
Filing date: 2022-11-03
Publication date: 2023-04-07
Anticipated expiration: 2032-11-03

Abstract

The utility model relates to a MVR evaporation system of resource processing preserved szechuan pickle waste water in coordination, including advanced oxidation-fenton pretreatment system (I), coarse salt MVR evaporation crystal system (II) and refined salt MVR evaporation crystal system (III). The recycling system needs to be matched with a town sewage treatment plant for use, concentrated mother liquor with 5-10% of feeding quantity and distilled water are discharged to the town sewage treatment plant for subsequent biochemical treatment through the treatment of the recycling system, and then discharged. By taking 15% of sodium chloride in the preserved szechuan pickle wastewater, the system adopts a crude salt-refined salt two-stage evaporation system, can recycle 60-80% of sodium chloride in the preserved szechuan pickle wastewater, achieves the recycling standard of preserved szechuan pickle salt, and realizes the resource utilization of the preserved szechuan pickle wastewater; meanwhile, more than 50 percent of COD and 60 to 80 percent of salt are extracted by the resource system, so that organic matters and salt entering the urban sewage plant are effectively reduced, the flora of the urban sewage plant is effectively protected, and the stability is improved.

Description

MVR evaporation system for cooperatively recycling preserved szechuan pickle wastewater

Technical Field

The utility model belongs to the technical field of high COD waste water treatment of high salt and utilization, a MVR evaporation system of resourceful treatment preserved szechuan pickle waste water in coordination is related to.

Background

The tuber mustard is a special prop industry in Chongqing areas, is one of special benefit agriculture in Chongqing cities, and has the advantages that the production scale is gradually enlarged along with the rapid economic development of the three gorges reservoir area, more and more high-salt, high-concentration and high-nitrogen and phosphorus wastewater is generated in the processing process, and the water environment safety of the reservoir area is seriously threatened. The production process and the pollution production flow of the preserved szechuan pickle are shown in figure 1, and it can be seen that a large amount of waste water is generated by the preserved szechuan pickle waste water in different stages of the preserved szechuan pickle production, such as salting, elutriation, desalination, dehydration, sterilization and cooling, and the waste water has the characteristics of high salt and high COD, and seriously threatens the water environment safety of the three gorges reservoir area. In addition, in Chongqing, local standard document "water pollutant discharge standard of preserved szechuan pickle industry" (DB 50/1050-2020) is implemented from 1 month and 1 day in 2021, and important basis is provided for strengthening water pollutant discharge management of preserved szechuan pickle production enterprises by ecological environment protection departments at all levels. According to the standard, the chloride control standard of the preserved szechuan pickle wastewater is within 8000 mg/L. In 2025, stricter standards were implemented requiring chloride to be controlled to within 5000 mg/L. Therefore, how to effectively treat the preserved szechuan pickle wastewater is a problem which is concerned about, how to increase the treatment strength of the preserved szechuan pickle industrial wastewater, promote the reduction of the preserved szechuan pickle industrial wastewater and the innovation of the treatment technology, and have very important functions in the aspects of clean production, the resource utilization of the wastewater, the water environment protection of the three gorges reservoir area and the like in the preserved szechuan pickle industry.

The technology for treating the preserved szechuan pickle wastewater can be divided into a physical and chemical method, a biological method and a physical and chemical biological combined process, and the biological and physical biological combined process is mainly used. These methods include: coagulating sedimentation, electrochemical oxidation, fenton oxidation, aeration micro-electrolysis, iron-carbon micro-electrolysis, an Anaerobic Sequencing Batch Biofilm Reactor (ASBBR), a Sequencing Batch Biofilm Reactor (SBBR), a Membrane Bioreactor (MBR), an aeration biological filter, an up-flow anaerobic sludge bed reactor (UASB), a novel biological rotating cage, a microbial fuel cell and the like. For example, (1) the Fenton catalytic oxidation treatment technology has mild reaction conditions, high treatment efficiency and wide application range, can effectively remove phosphate and COD in the preserved szechuan pickle wastewater by adjusting parameters such as divalent Fe, hydrogen peroxide, pH and the like, has ideal removal effect on organic matters and phosphate, but has limited removal effect on COD, and has H ₂ O ₂ The dosage is large, and the treatment cost is high; (2) the results of the microbial fuel cell for treating the preserved szechuan pickle wastewater show that the pollutant removal effect is not ideal, and simultaneously, the pollutant cannot be removed, and the problems that the acclimation degree of salt-tolerant microbes is limited, the anaerobic process is difficult to start and is easy to acidify, the salt-tolerant bacteria are sensitive to the salinity change, the biodegradation rate is obviously influenced by the salinity and the like still exist at present; (3) the MBR process provides a feasible route for the efficient treatment of the salt-containing wastewater by a biological method due to the forced interception of microorganisms and no restriction of sludge settleability, can effectively remove COD in water, has stable operation and strong impact load resistance, and all indexes of effluent reach the first-level A standard. MBR plays an important role in realizing efficient biological treatment of salt-containing wastewater, but the membrane pollution problem needs to be focused in the operation process, and the MBR needs to be regularly usedAnd (3) adopting a mixed solution of NaOH and NaClO to chemically clean the membrane wires. Other combined treatment methods of the tuber mustard wastewater, such as a chemical phosphorus removal-hydrolytic acidification-anaerobic contact-contact oxidation process, a UASB-aerobic-coagulation process, a hydrolytic acidification-SBR-coagulation process, an anaerobic/biological phosphorus removal/biological nitrogen removal/chemical phosphorus removal combined process and the like, are applied to phosphorus removal or COD removal, but rarely relate to the aspect of resource recycling of high salt. The method has good effect on the wastewater generated after the third pickling, and particularly the preserved szechuan pickle wastewater belongs to the conventional food production wastewater, the organic matters of the preserved szechuan pickle wastewater have biodegradability, and the low-salt preserved szechuan pickle wastewater can reach the standard after biochemical treatment by a town sewage plant.

The high-salt and high-COD waste water 5 which is pickled for the first time, the second time and the third time is the most difficult part to treat, and although the pickled water for the second time and the third time can prepare the preserved szechuan pickle soy sauce, the taste is far worse than that of the conventional soy sauce, and the market acceptance is not high. The salt content for the first and second salting is maximum, the salt content for every 100kg of preserved szechuan pickle is about 4kg during the first salting, the generated high-salt water has bitter taste, the salt content for every 100kg of preserved szechuan pickle is about 10kg during the second salting, the salt content for every 100kg of preserved szechuan pickle is about 2kg during the third salting, the three salting all generate high-salt high-COD waste water, the salinity is more than 10%, and the COD is more than 20000ppm. The waste water of the third pickling is generally discharged into a town sewage plant to be mixed and diluted with conventional domestic sewage, and then is discharged into the environment after biochemical treatment. As the waste water amount of the tuber mustard is increased day by day, more and more high-salt and high-COD are discharged into town sewage plants, great damage is caused to biochemical systems of the sewage plants, and the recovery is difficult after the flora imbalance. Therefore, it is urgent to reduce the salt and organic matters from entering the sewage plant. For example, the process of removing the high salt content in the preserved szechuan pickle wastewater by using a coagulation sedimentation-MVR evaporative crystallization method is shown in FIG. 2, and the principle of the method is that the coagulation sedimentation is mainly used as a pretreatment process, and the colloid generated by the chemical reaction of a coagulant (PAC, PAM and the like) is mainly utilized to neutralize the foreign charges on the surfaces of certain substances in the preserved szechuan pickle wastewater, so that the suspended substances are flocculated, aggregated and finally settled and separated, and the removal rate of the suspended substances is high (> 90%), but the removal rate of COD is low. And (4) evaporating and crystallizing by MVR to generate recycled salt, wherein the salt still contains higher COD (chemical oxygen demand), and the COD adversely affects the taste or the safety of the finished preserved szechuan pickle.

The release of the water pollutant emission standard of the tuber mustard industry guides tuber mustard enterprises to start from three aspects of tuber mustard production source, process and tail end, promotes the innovation of the waste water reduction and treatment technology of the tuber mustard industry, and lays a foundation for the aspects of clean production, waste water resource utilization, water environment protection of three gorges reservoir area and the like of the tuber mustard industry. From the source, the preserved szechuan pickle production enterprises should reduce the salt consumption in the pickling process and increase the reuse rate of the salt-containing water; the preserved szechuan pickle wastewater is conveyed to a self-built sewage treatment facility or a park sewage treatment plant or a town sewage treatment plant for treatment, and is discharged after reaching the standard in a specified area of a pollution discharge permit; the direct discharge of the preserved szechuan pickle wastewater to the environment is forbidden. In the process, the preserved szechuan pickle production enterprises should adopt the technology of reducing the water consumption for desalination and recycle or comprehensively utilize the high-salt water. At the end, the pH, the chemical oxygen demand, suspended matters, ammonia nitrogen, total phosphorus and chloride (Cl) of the mustard tuber wastewater discharge need to be strictly monitored ^- ) And the indexes such as total nitrogen and the like meet the requirement of implementing refined management and control on high-salt water in the tuber mustard industry, and corresponding water pollutant emission limit values are executed according to different product varieties. In addition, the treatment of the preserved szechuan pickle wastewater has the particularity, such as discontinuous discharge of the preserved szechuan pickle wastewater, high salt content, high cost of the existing treatment technology, poor standard-reaching stability of the prior art and the like, and the factors are bottlenecks which restrict the treatment of the preserved szechuan pickle wastewater.

Aiming at the problems of the preserved szechuan pickle wastewater, the treatment cost of the preserved szechuan pickle wastewater is reduced by taking the aspects of resource utilization and standard discharge of high salt of the preserved szechuan pickle wastewater into consideration. The utility model provides a MVR evaporation-sewage plant makes tuber mustard waste water resource system processing system in coordination. The method mainly comprises the steps that an advanced oxidation-Fenton pretreatment system removes organic matters, COD, odor and the like, and is beneficial to the operation of a subsequent MVR evaporation system; the coarse salt-refined salt two-stage MVR evaporative crystallization system can recover 60-80% of sodium chloride, and ensure the standard QB/T2830-2015 preserved szechuan pickle salt for recovering salt composite preserved szechuan pickle salt, thereby realizing the recycling of the preserved szechuan pickle wastewater; meanwhile, more than 50% of COD and 60-80% of salt are extracted by the system, so that organic matters and salt entering the urban sewage plant are greatly reduced, and the inhibition effect on a biological treatment system is obviously reduced. The system needs to be matched with a town sewage treatment plant for use, concentrated mother liquor with the feed quantity of 5-10% is discharged from an evaporation system, and distilled water is discharged to the town sewage treatment plant for subsequent biochemical treatment and then is discharged.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model discloses a solve the problem that the high COD waste water of preserved szechuan pickle high salt commonly used can't directly get into the processing of cities and towns sewage plant, provide a MVR evaporation system of resource processing preserved szechuan pickle waste water in coordination.

In order to achieve the above purpose, the utility model provides a following technical scheme:

1. an MVR evaporation system for cooperatively recycling tuber mustard wastewater comprises an advanced oxidation-Fenton pretreatment system (I), a crude salt MVR evaporation crystallization system (II) and a refined salt MVR evaporation crystallization system (III) which are sequentially connected;

the advanced oxidation-Fenton pretreatment system (I) comprises a raw material storage pool 3, a Fenton reaction tank 11, a neutralization tank 14 and a horizontal decanter centrifuge 19 which are sequentially connected, wherein the Fenton reaction tank 11 is connected with H ₂ O ₂ Storage tank 1A and FeCl ₂ A NaOH storage tank 1D and a compressed air pipe 16 are connected to the storage tank 1C and the neutralization tank 14, wherein the Fenton reaction tank outlet 12 of the Fenton reaction tank 11 is connected with the neutralization tank inlet 15 of the neutralization tank 14;

the crude salt MVR evaporative crystallization system (II) comprises a crude salt MVR feeding tank 22, a crude salt MVR separator 30 and a crude salt MVR solid-liquid separation centrifuge 28 which are sequentially connected;

the refined salt MVR evaporation crystallization system (III) comprises a crude salt dissolving tank 35, a refined salt MVR feeding tank 36, a refined salt MVR separator 44 and a refined salt MVR solid-liquid separation centrifuge 42 which are sequentially connected;

wherein a clear liquid outlet 20 of a horizontal screw centrifuge 19 in the advanced oxidation-Fenton pretreatment system (I) is connected with an inlet of a crude salt MVR feeding tank 22 in a crude salt MVR evaporation crystallization system (II), an outlet of a crude salt MVR solid-liquid separation centrifuge 28 in the crude salt MVR evaporation crystallization system (II) is respectively connected with an inlet of a crude salt dissolving tank 35 in a town sewage treatment system and a refined salt MVR evaporation crystallization system (III), and an outlet of a refined salt MVR solid-liquid separation centrifuge 42 in the refined salt MVR evaporation crystallization system (III) is connected with the town sewage treatment system.

Preferably, the top inlet of the Fenton reaction tank 11 comprises H which is introduced into the bottom of the Fenton reaction tank 11 ₂ O ₂ Inlet tube 9 and FeCl ₂ Inlet pipe 10, wherein H ₂ O ₂ Inlet pipe 9 and H ₂ O ₂ H is arranged between the storage tanks 1A ₂ O ₂ Diaphragm pump 2A, feCl ₂ Inlet tube 10 and FeCl ₂ FeCl is arranged between the storage tanks 1C ₂ A diaphragm pump 2D;

a raw material inlet pipe 8 which is introduced into the bottom of the Fenton reaction tank 11 is arranged at an inlet on one side of the Fenton reaction tank 11, wherein the raw material inlet pipe 8 is connected with a pipeline mixer 6, a first pH meter 7A is arranged in the middle of the raw material inlet pipe 8, the pipeline mixer 6 is respectively connected with an HCl storage tank 1B and a raw material storage tank 3, an advanced oxidation feed pump 2C is arranged between the raw material storage tank 3 and the pipeline mixer 6, the raw material storage tank 3 is provided with a raw material storage tank liquid level meter 4A, and an HCl diaphragm pump 2B is arranged between the HCl storage tank 1B and the pipeline mixer 6;

a Fenton reaction tank outlet 12 on the other side of the Fenton reaction tank 11 is connected with a neutralization tank inlet 15 of a neutralization tank 14, and a neutralization tank outlet 18 of the neutralization tank 14 is connected with a horizontal screw centrifuge 19;

a first variable-frequency stirrer 13A and a Fenton reaction tank liquid level meter 4B are arranged at the top of the Fenton reaction tank 11, and a second pH meter 7B is arranged on the side surface of the Fenton reaction tank 11;

the top inlet of the neutralization tank 14 comprises a compressed air pipe 16 and a NaOH pipe 17 which are introduced into the bottom of the neutralization tank 14, wherein the NaOH pipe 17 is connected with a NaOH storage tank 1D and is provided with a NaOH diaphragm pump 2E;

a second variable-frequency stirrer 13B and a neutralization tank liquid level meter 4C are arranged at the top of the neutralization tank 14, and a third pH meter 7C is arranged in the neutralization tank 14;

the horizontal decanter centrifuge 19 is provided with a solid outlet 21 and a clear liquid outlet 20, the clear liquid outlet 20 of the horizontal decanter centrifuge 19 is connected with a crude salt MVR feeding tank 22 in the crude salt MVR evaporative crystallization system (II), wherein the crude salt MVR feeding tank 22 is provided with a clear liquid tank level meter 4D.

Preferably, the crude salt MVR separator 30 is formed by connecting an upper crude salt MVR crystallizer 31 and a lower crude salt MVR crystallization leg 32, and a crude salt MVR discharge circulating pump 26 is arranged between the crude salt MVR crystallizer 31 and the crude salt MVR crystallization leg 32;

the crude salt MVR crystallizer 31 is respectively connected with the top end and the bottom of the crude salt MVR heater 29, a crude salt MVR forced circulation pump 25 is arranged between the bottom of the crude salt MVR heater 29 and the crude salt MVR crystallizer 31, and the lower part of the crude salt MVR heater 29 is connected with a crude salt MVR condensed water negative pressure pump 24;

the crude salt MVR crystallizer 31 is respectively connected with a crude salt MVR cyclone separator 33 and a crude salt MVR cyclone separator demisting device 34, wherein the crude salt MVR cyclone separator demisting device 34 is communicated with the crude salt MVR cyclone separator 33 positioned right below, and a crude salt MVR vapor compressor 27 is arranged between the crude salt MVR cyclone separator demisting device 34 and the crude salt MVR crystallizer 31;

a crude salt MVR feeding pump 23 is arranged between the crude salt MVR feeding tank 22 and the crude salt MVR crystallizer 31.

Preferably, the refined salt MVR separator 44 consists of an upper refined salt MVR crystallizer 45 and a refined salt MVR crystallization leg 46 located directly below;

a refined salt MVR discharging circulating pump 40 is arranged between the refined salt MVR crystallizer 45 and the refined salt MVR crystallization leg 46;

the refined salt MVR crystallizer 45 is respectively connected with the top end and the bottom of the refined salt MVR heater 43, a refined salt MVR forced circulation pump 39 is arranged between the bottom of the refined salt MVR heater 43 and the refined salt MVR crystallizer 45, and the lower part of the refined salt MVR heater 43 is connected with a refined salt MVR condensed water negative pressure pump 38;

the refined salt MVR crystallizer 45 is respectively connected with a refined salt MVR cyclone separator 47 and a refined salt MVR cyclone separator demisting device 48, wherein the refined salt MVR cyclone separator demisting device 48 is communicated with the refined salt MVR cyclone separator 47 positioned right below, and a refined salt MVR vapor compressor 41 is arranged between the refined salt MVR cyclone separator demisting device 48 and the refined salt MVR crystallizer 45;

the side surface of the crude salt dissolving tank 35 is provided with a crude salt dissolving tank liquid level meter 4E, and the top part is provided with a third variable frequency stirrer 13C;

the side of the refined salt MVR feeding tank 36 is provided with a refined salt MVR feeding tank liquid level meter 4F, wherein a refined salt MVR feeding pump 37 is arranged between the refined salt MVR feeding tank 36 and the refined salt MVR crystallizer 45.

Preferably, the outlet of the crude salt MVR solid-liquid separation centrifuge 28 and the outlet of the refined salt MVR solid-liquid separation centrifuge 42 are respectively connected with the mother liquor inlet 5 in the raw material storage tank 3.

2. The method for treating the preserved szechuan pickle wastewater in a synergistic recycling manner is carried out by adopting the device and specifically comprises the following steps:

(1) In an advanced oxidation-Fenton pretreatment system (I), an HCl solution in an HCl storage tank 1B and preserved szechuan pickle wastewater to be treated in a raw material storage tank 3 are mixed in a pipeline mixer 6, the pH is adjusted to 3-4 by a first pH meter 7A, and then the mixture is introduced into the bottom of a Fenton reaction tank 11 and respectively treated by a second pH meter H ₂ O ₂ H introduced into the bottom of the Fenton reaction tank 11 in the storage tank 1A ₂ O ₂ From FeCl ₂ FeCl introduced into the bottom of the Fenton reaction tank 11 in the storage tank 1C ₂ The Fenton reaction is carried out, the reaction solution enters the bottom of the neutralization tank 14 after the reaction is finished, the neutralization reaction is carried out on the reaction solution and NaOH solution entering the bottom of the neutralization tank 14 from a NaOH storage tank 1D, the pH value of the reaction process is adjusted by a third pH meter 7C arranged in the neutralization tank 14, after the reaction is finished, the feed liquid overflows into a horizontal screw centrifuge 19 from an outlet 18 at the upper part of the neutralization tank 14 to realize solid-liquid separation, the solid is discharged from a solid outlet 21, and the liquid enters a crude salt MVR feeding tank 22 of a crude salt MVR evaporative crystallization system (II) through a clear liquid outlet 20;

(2) In a crude salt MVR evaporative crystallization system (II), pumping crude salt in a crude salt MVR feeding tank 22 into a crude salt MVR crystallizer 31 of a crude salt MVR separator 30 for evaporative crystallization, separating out the crude salt from a crude salt MVR crystallization leg 32 below, feeding the crude salt into a crude salt MVR discharging circulating pump 26, feeding a liquid part into a town sewage treatment system connected with the liquid part, and feeding a solid part into a crude salt dissolving tank 35 in a refined salt MVR evaporative crystallization system (III);

(3) In the refined salt MVR evaporation crystallization system (III), crude salt is mixed and dissolved with water in a crude salt dissolving tank 35 and then enters a refined salt MVR feeding tank 36, then enters a refined salt MVR crystallizer 45 for evaporation crystallization, enters a refined salt MVR solid-liquid separation centrifuge 42 from a refined salt MVR crystallization leg 46 below, a liquid part enters a town sewage treatment system connected with the liquid part, and a solid part is refined salt for recycling.

Preferably, an HCl diaphragm pump 2B is arranged between the HCl storage tank 1B and the pipeline mixer 6, and the HCl diaphragm pump 2B and the first pH meter 7A are linked to adjust the pH, specifically: the pH value of the first pH meter 7A is set to be 3.5, and the feeding amount is adjusted through the HCl diaphragm pump 2B, so that the pH value of the mixed feed liquid is 3-4;

be provided with NaOH diaphragm pump 2E between NaOH storage tank 1D and neutralization tank 14, pH is adjusted in NaOH diaphragm pump 2E and the linkage of third pH meter 7C, specifically is: by setting the pH value of the third pH meter 7C to 7.5, the feed amount adjustment was performed by the NaOH diaphragm pump 2E.

Preferably, the volume ratio of the crude salt to the water in the crude salt dissolving tank 35 is 1.

The beneficial effects of the utility model reside in that: the utility model discloses a MVR evaporation system of resource processing preserved szechuan pickle waste water in coordination has good treatment effect to the preserved szechuan pickle waste water, mainly embodies: (1) The advanced oxidation-Fenton system is arranged in the system of the utility model, 50% of organic matters in the high-salt and high-COD preserved szechuan pickle wastewater can be removed firstly, namely 50% of organic matters are reduced to enter a subsequent town sewage treatment plant; secondly, the advanced oxidation-Fenton system can eliminate COD and odor of the preserved szechuan pickle wastewater, so that recycled salt meeting the preserved szechuan pickle salt standard is obtained subsequently and recycled in the production of preserved szechuan pickle, and the recycling of the preserved szechuan pickle wastewater is realized; and finally, the removal of the organic matters enables a subsequent evaporative crystallization system to operate stably, and the risk of foaming and pipe blockage during evaporation is eliminated. (2) The utility model discloses a be provided with coarse salt MVR evaporation crystallization system and refined salt MVR evaporation crystallization system in the system, obtain coarse salt by coarse salt MVR evaporation crystallization system, then obtain the refined salt by coarse salt MVR evaporation crystallization system, the refined salt can reach preserved szechuan pickle salt standard (& lt & gt QB/T2830-2015 preserved szechuan pickle salt & gt), the resource rate of recovery is greater than 60%. (3) The utility model discloses the thick salt MVR evaporation crystallization system and the fine salt MVR evaporation crystallization system that set up adopt the cyclone of taking the silk screen defogging device, contain the salt branch lower in the steam, can protect vapor compressor effectively, and the comdenstion water after the while evaporation is very pure. (4) The utility model discloses thick salt MVR evaporation crystallization system and refined salt MVR evaporation crystallization system adopt the temperature to evaporate at 60 ~ 70 ℃, except that the steam compressor seals need steam and outside, do not need extra steam to supply, can reach 60-70kwh electric evaporation one ton water.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and/or combinations particularly pointed out in the appended claims.

Drawings

FIG. 1 is a flow chart of a production process and a pollution production process of preserved szechuan pickle;

FIG. 2 is a flow chart of removing high salt from the preserved szechuan pickle wastewater by adopting a coagulating sedimentation-MVR evaporation crystallization mode;

FIG. 3 is a structural diagram of the MVR evaporation system for the cooperative recycling treatment of the preserved szechuan pickle wastewater of the utility model;

FIG. 4 is a schematic diagram of the advanced oxidation-Fenton pretreatment system (I) of the present invention;

FIG. 5 is a structural diagram of the crude salt MVR evaporative crystallization system (II) of the present invention;

FIG. 6 is a structural diagram of the refined salt MVR evaporation crystallization system (III) of the present invention;

FIG. 7 is a flow chart of the MVR evaporation system for the cooperative recycling treatment of the tuber mustard wastewater for treating the tuber mustard high-salt wastewater in Taojiang county, chongqing city;

FIG. 8 is a flow chart of the treatment of the waste water of preserved szechuan pickle in the laboratory;

wherein 1A is H ₂ O ₂ Storage tank, HCl storage tank as 1B, feCl storage tank as 1C ₂ Storage tank, 1D NaOH storage tank and 2A H ₂ O ₂ Diaphragm pump, 2B HCl diaphragm pump, 2C advanced oxidation feed pump, 2D FeCl ₂ A diaphragm pump, a NaOH diaphragm pump as 2E, a raw material storage tank as 3, a raw material storage tank liquid level meter as 4A, a Fenton reaction tank liquid level meter as 4B and a neutralization tank as 4CA liquid level meter, a clear liquid tank liquid level meter, a crude salt dissolving tank liquid level meter, a refined salt MVR feeding tank liquid level meter, a mother liquid inlet, a pipeline mixer, a first pH meter, a second pH meter, a third pH meter, a raw material inlet pipe and a raw material inlet pipe, wherein the clear liquid tank liquid level meter is 4D, the crude salt dissolving tank liquid level meter is 4E, the refined salt MVR feeding tank liquid level meter is 4F, the mother liquid inlet is 5, the pipeline mixer is 6, the first pH meter is 7A, the second pH meter is 7B, the third pH meter is 7C, the raw material inlet pipe is 8, and the raw material inlet pipe are 9H ₂ O ₂ Inlet pipe, 10 is FeCl ₂ An inlet pipe, 11 is a Fenton reaction tank, 12 is a Fenton reaction tank outlet, 13A is a first frequency conversion stirrer, 13B is a second frequency conversion stirrer, 13C is a third frequency conversion stirrer, 14 is a neutralization tank, 15 is a neutralization tank inlet, 16 is a compressed air pipe, 17 is an NaOH pipe, 18 is a neutralization tank outlet, 19 is a horizontal screw centrifuge, 20 is a horizontal screw centrifuge clear liquid outlet, 21 is a horizontal screw centrifuge solid outlet, 22 is a crude salt MVR feeding tank, 23 is a crude salt MVR feeding pump, 24 is a crude salt MVR condensed water negative pressure pump, 25 is a crude salt MVR forced circulation pump, 26 is a crude salt MVR discharging circulation pump, 27 is a crude salt MVR steam compressor, 28 is a crude salt MVR solid-liquid separation centrifuge, 29 is a crude salt MVR heater 30 is a crude salt MVR separator, 31 is a crude salt MVR crystallizer, 32 is a crude salt MVR crystallization leg, 33 is a crude salt MVR cyclone separator, 34 is a crude salt MVR cyclone defogging device, 35 is a crude salt dissolving tank, 36 is a refined salt MVR feeding tank, 37 is a refined salt MVR feeding pump, 38 is a refined salt MVR condensed water negative pressure pump, 39 is a refined salt MVR forced circulation pump, 40 is a refined salt MVR discharging circulation pump, 41 is a refined salt MVR vapor compressor, 42 is a refined salt MVR solid-liquid separation centrifuge, 43 is a refined salt MVR heater, 44 is a refined salt MVR separator, 45 is a refined salt MVR crystallizer, 46 is a refined salt MVR crystallization leg, 47 is a refined salt MVR cyclone separator, and 48 is a refined salt MVR cyclone defogging device.

Detailed Description

The following embodiments of the present invention are provided by way of specific examples, and other advantages and effects of the present invention will be readily apparent to those skilled in the art from the disclosure herein. The present invention can also be implemented or applied through other different specific embodiments, and various details in the present specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention in a schematic way, and the features in the following embodiments and examples can be combined with each other without conflict.

Wherein the showings are for the purpose of illustrating the invention only and not for the purpose of limiting the same, and in which there is shown by way of illustration only and not in any way limiting the scope of the invention; for a better understanding of the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "back", etc., indicating directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for convenience of description and simplification of description, but it is not intended to indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore, the terms describing the positional relationships in the drawings are only used for illustrative purposes and are not to be construed as limiting the present invention, and those skilled in the art can understand the specific meanings of the terms according to specific situations.

Example 1:

the utility model provides a MVR vaporization system of resource processing preserved szechuan pickle waste water in coordination, its structure is shown as figure 3, and MVR vaporization system is including the advanced oxidation-fenton pretreatment system (I) that connects gradually among this system (as shown in figure 4, including consecutive raw materials reservoir 3, fenton retort 11, neutralization tank 14 and horizontal spiral shell centrifuge 19, and wherein fenton retort 11 is connected with H centrifuge ₂ O ₂ Storage tanks 1A and HCl storage tank 1B, neutralization tank 14 is connected with NaOH storage tank 1D), crude salt MVR evaporative crystallization system (II) (as shown in FIG. 5, including crude salt MVR feed tank 22, crude salt MVR separator 30 and crude salt MVR solid-liquid separation centrifuge 28 that link to each other in proper order) and refined salt MVR evaporative crystallization system (III) (as shown in FIG. 6, including crude salt dissolving tank 35, refined salt MVR feed tank 36, refined salt MVR separator 44 and refined salt MVR solid-liquid separation centrifuge 28 that link to each other in proper orderA separator centrifuge 42).

In the above advanced oxidation-Fenton pretreatment system (I), the top inlet of the Fenton reaction tank 11 contains H which is introduced into the bottom of the Fenton reaction tank 11 ₂ O ₂ Inlet tube 9 and FeCl ₂ Inlet tube 10 of which H ₂ O ₂ Inlet pipe 9 and H ₂ O ₂ H is arranged between the storage tanks 1A ₂ O ₂ Diaphragm pump 2A, feCl ₂ Inlet tube 10 and FeCl ₂ FeCl is arranged between the storage tanks 1C ₂ A diaphragm pump 2D; a raw material inlet pipe 8 which is introduced into the bottom of the Fenton reaction tank 11 is arranged at a side inlet of one side of the Fenton reaction tank 11, wherein the raw material inlet pipe 8 is connected with a pipeline mixer 6, a first pH meter 7A is arranged in the middle of the raw material inlet pipe 8, the pipeline mixer 6 is respectively connected with an HCl storage tank 1B and a raw material storage tank 3, an advanced oxidation feed pump 2C is arranged between the raw material storage tank 3 and the pipeline mixer 6, the raw material storage tank 3 is provided with a raw material storage tank liquid level meter 4A, and an HCl diaphragm pump 2B is arranged between the HCl storage tank 1B and the pipeline mixer 6; a Fenton reaction tank outlet 12 on the other side of the Fenton reaction tank 11 is connected with a neutralization tank inlet 15 of a neutralization tank 14, and a neutralization tank outlet 18 of the neutralization tank 14 is connected with a horizontal screw centrifuge 19; a first variable-frequency stirrer 13A and a Fenton reaction tank liquid level meter 4B are arranged at the top of the Fenton reaction tank 11, and a second pH meter 7B is arranged on the side surface of the Fenton reaction tank 11; the top inlet of the neutralization tank 14 comprises a compressed air pipe 16 and a NaOH pipe 17 which are introduced into the bottom of the neutralization tank 14, wherein the NaOH pipe 17 is connected with a NaOH storage tank 1D and is provided with a NaOH diaphragm pump 2E; a second variable-frequency stirrer 13B and a neutralization tank liquid level meter 4C are arranged at the top of the neutralization tank 14, and a third pH meter 7C is arranged in the neutralization tank 14; the horizontal decanter centrifuge 19 is provided with a solid outlet 21 and a clear liquid outlet 20, the clear liquid outlet 20 of the horizontal decanter centrifuge 19 is connected with a crude salt MVR feeding tank 22 in the II, wherein the crude salt MVR feeding tank 22 is provided with a clear liquid tank level gauge 4D.

In the crude salt MVR evaporative crystallization system (II), the crude salt MVR separator 30 is formed by connecting an upper crude salt MVR crystallizer 31 and a lower crude salt MVR crystallization leg 32, and a crude salt MVR discharge circulation pump 26 is arranged between the crude salt MVR crystallizer 31 and the crude salt MVR crystallization leg 32; the crude salt MVR crystallizer 31 is respectively connected with the top end and the bottom of the crude salt MVR heater 29, a crude salt MVR forced circulation pump 25 is arranged between the bottom of the crude salt MVR heater 29 and the crude salt MVR crystallizer 31, and the lower part of the crude salt MVR heater 29 is connected with a crude salt MVR condensed water negative pressure pump 24; the coarse salt MVR crystallizer 31 is respectively connected with a coarse salt MVR cyclone separator 33 and a coarse salt MVR cyclone separator demisting device 34, wherein the coarse salt MVR cyclone separator demisting device 34 is communicated with the coarse salt MVR cyclone separator 33 positioned right below, and a coarse salt MVR vapor compressor 27 is arranged between the coarse salt MVR cyclone separator demisting device 34 and the coarse salt MVR crystallizer 31; a crude salt MVR feeding pump 23 is arranged between the crude salt MVR feeding tank 22 and the crude salt MVR crystallizer 31.

In the above-mentioned refined salt MVR evaporative crystallization system (III), the refined salt MVR separator 44 is composed of an upper refined salt MVR crystallizer 45 and a refined salt MVR crystallization leg 46 located right below; a refined salt MVR discharging circulating pump 40 is arranged between the refined salt MVR crystallizer 45 and the refined salt MVR crystallization leg 46; the refined salt MVR crystallizer 45 is respectively connected with the top end and the bottom of the refined salt MVR heater 43, a refined salt MVR forced circulation pump 39 is arranged between the bottom of the refined salt MVR heater 43 and the refined salt MVR crystallizer 45, and the lower part of the refined salt MVR heater 43 is connected with a refined salt MVR condensed water negative pressure pump 38; the refined salt MVR crystallizer 45 is respectively connected with a refined salt MVR cyclone separator 47 and a refined salt MVR cyclone separator demisting device 48, wherein the refined salt MVR cyclone separator demisting device 48 is communicated with the refined salt MVR cyclone separator 47 positioned right below, and a refined salt MVR vapor compressor 41 is arranged between the refined salt MVR cyclone separator demisting device 48 and the refined salt MVR crystallizer 45; the side surface of the crude salt dissolving tank 35 is provided with a crude salt dissolving tank liquid level meter 4E, and the top part is provided with a third variable frequency stirrer 13C; the side of the refined salt MVR feeding tank 36 is provided with a refined salt MVR feeding tank liquid level meter 4F, wherein a refined salt MVR feeding pump 37 is arranged between the refined salt MVR feeding tank 36 and the refined salt MVR crystallizer 45.

In addition, in order to further recover the refined salt for recycling, an outlet of the crude salt MVR solid-liquid separation centrifuge 28 and the refined salt MVR solid-liquid separation centrifuge 42 are respectively connected with the mother liquor inlet 5 in the raw material storage tank 3, so that the liquid generated by centrifuging in the crude salt MVR solid-liquid separation centrifuge 28 and the refined salt MVR solid-liquid separation centrifuge 42 can enter the raw material storage tank 3 again in a stockbreeding mode for the next round of treatment.

The MVR evaporation system for treating the preserved szechuan pickle wastewater in a synergistic and resource mode is adopted to treat the preserved szechuan pickle wastewater, and the specific treatment steps are as follows:

(1) In an advanced oxidation-Fenton pretreatment system (I), HCl solution in an HCl storage tank 1B is mixed with preserved szechuan pickle wastewater to be treated in a raw material storage tank 3, the pH is adjusted to 3-4, and then the mixture is introduced into the bottom of a Fenton reaction tank 11 and is respectively treated by a secondary oxidation reactor H ₂ O ₂ H introduced into the bottom of the Fenton reaction tank 11 in the storage tank 1A ₂ O ₂ From FeCl ₂ FeCl introduced into the bottom of the Fenton reaction tank 11 in the storage tank 1C ₂ Fenton reaction occurs, after the reaction is finished, the obtained product enters the bottom of a neutralization tank 14 and is subjected to neutralization reaction with NaOH solution entering the bottom of the neutralization tank 14 from a NaOH storage tank 1D, after the reaction is finished, feed liquid overflows into a horizontal screw centrifuge 19 from an outlet 18 at the upper part of the neutralization tank 14 to realize solid-liquid separation, solid is discharged from a solid outlet 21, and liquid enters a crude salt MVR feeding tank 22 of a crude salt MVR evaporative crystallization system (II) through a clear liquid outlet 20;

(3) In the refined salt MVR evaporation crystallization system (III), crude salt is mixed with water (the volume ratio is 1-3) in a crude salt dissolving tank 35 and then enters a refined salt MVR feeding tank 36, then enters a refined salt MVR crystallizer 45 for evaporation crystallization, enters a refined salt MVR solid-liquid separation centrifuge 42 from a refined salt MVR crystallization leg 46 at the lower part, a liquid part enters a town sewage treatment system connected with the liquid part, and a solid part is refined salt for recycling.

In the method, the HCl diaphragm pump 2B is linked with the first pH meter 7A, and the method specifically comprises the following steps: setting the pH value of a first pH meter 7A to be 3.5, and adjusting the feeding amount through an HCl diaphragm pump 2B to ensure that the pH value of the mixed feed liquid is 3-4; the NaOH diaphragm pump 2E is linked with the third pH meter 7C, and specifically comprises the following steps: by setting the pH value of the third pH meter 7C to 7.5, the feed amount adjustment was performed by the NaOH diaphragm pump 2E.

Example 2

The system and the method in the above example 1 are used for treating high-salinity wastewater of tuber mustard in underlay county of Chongqing city, the flow of which is shown in FIG. 7, and the results are shown in Table 1 and specifically described as follows:

1. the high-salinity waste water of the hot pickled mustard tuber comes from a certain hot pickled mustard tuber factory in Tanjiang county, chongqing city, the COD of the waste water is 22600mg/L, the NaCl content is 1.41 multiplied by 10 ⁵ mg/L, bluish green, pH 4.8 and pungent odor, adjusting pH of the wastewater to 3-4 by adding 1mol/L HCl solution, and adding FeCl ₂ ·4H ₂ O and H ₂ O ₂ And (3) beginning to carry out Fenton reaction, adjusting the pH value to 7-8 by adding 1mol/L NaOH solution after the Fenton reaction is finished, flocculating, standing, flocculating and filtering. Catalyst H in Fenton reaction ₂ O ₂ With Fe ²⁺ Specific molar ratios are shown in table 1, for example. The COD of the stock solution water is reduced from 22600mg/L to 17420-10120 mg/L through detection of the filtrate after the Fenton reaction, which shows that the COD in the wastewater can be obviously removed through the Fenton reaction, and the odor of the treated water sample disappears from the sense of smell. From the view of COD removal effect and economy of the water sample, the number 4 is the optimal condition because the consumption of hydrogen peroxide and ferrous chloride is the minimum, so the subsequent evaporation crystallization salt extraction treatment is carried out by selecting the process condition.

2. The subsequent advanced oxidation fenton reaction is carried out under the experimental conditions of the number 4, which specifically comprise: adding 200ml of 1mol/L HCl solution into 3L of wastewater to adjust the pH value of the wastewater to 3.4, and then adding 5.12g of FeCl ₂ ·4H ₂ After O (0.025 mol) was sufficiently dissolved by stirring, 300ml of 3wt% was slowly added with stirring ₂ O ₂ (0.25 mol), reacting for 120min after the addition is finished, adjusting the pH value to 7.4 by adding 260ml of 1mol/L NaOH solution for flocculation after the Fenton reaction is finished, standing for flocculation, and filtering.

3. And evaporating and crystallizing the filtrate after the completion of the Fenton oxidation reaction and suction filtration to obtain yellowish crude salt and evaporated condensate water. The distilled water may contain higher COD which cannot be discharged at will to pollute the environment, and the part can be discharged into a town sewage plant for advanced treatment.

4. The crude salt is dissolved and evaporated to crystallize to obtain white refined salt. The finished salt obtained by the process of evaporating, concentrating and crystallizing crude salt after advanced oxidation-evaporating, concentrating and crystallizing crude salt has the purity of 97.8 percent and the whiteness of 70, and nitrite and potassium ferrocyanide are not detected. According to the standard of QB/T2830-2015 preserved szechuan pickle salt, the finished salt can be reused for the production of pickled preserved szechuan pickle. In the experiment, 280g of finished salt is extracted from 3L of preserved szechuan pickle wastewater (the salt extraction rate is 65%). After the whole process is finished, 200ml of mother liquor is remained, the small amount of mother liquor is a sodium chloride saturated solution, and COD is also enriched to a high degree and can be discharged into a town sewage plant for advanced treatment, so the COD value of the mother liquor is not tested in the experiment.

TABLE 1 Fenton's experimental conditions and results for mustard tuber waste water

Therefore, compare in the processing procedure of preserved szechuan pickle waste water in the laboratory (as shown in fig. 8), the utility model discloses a MVR evaporation system of resource processing preserved szechuan pickle waste water has good treatment effect to the preserved szechuan pickle waste water, mainly embodies: (1) The advanced oxidation-Fenton system is arranged in the system of the utility model, 50% of organic matters in the high-salt and high-COD preserved szechuan pickle wastewater can be removed firstly, namely 50% of organic matters are reduced to enter a subsequent town sewage treatment plant; secondly, the advanced oxidation-Fenton system can eliminate COD and odor of the preserved szechuan pickle wastewater, so that recycled salt meeting the preserved szechuan pickle salt standard is obtained subsequently and recycled in the production of preserved szechuan pickle, and the recycling of the preserved szechuan pickle wastewater is realized; and finally, the removal of the organic matters enables a subsequent evaporative crystallization system to operate stably, and the risk of foaming and pipe blockage during evaporation is eliminated. (2) The utility model discloses a be provided with coarse salt MVR evaporation crystallization system and refined salt MVR evaporation crystallization system in the system, obtain coarse salt by coarse salt MVR evaporation crystallization system, then obtain the refined salt by coarse salt MVR evaporation crystallization system, the refined salt can reach preserved szechuan pickle salt standard (& lt & gt QB/T2830-2015 preserved szechuan pickle salt & gt), the resource rate of recovery is greater than 60%. (3) The utility model discloses the thick salt MVR evaporation crystallization system and the fine salt MVR evaporation crystallization system that set up adopt the cyclone of taking the silk screen defogging device, contain the salt branch lower in the steam, can protect vapor compressor effectively, and the comdenstion water after the while evaporation is very pure. (4) The utility model discloses thick salt MVR evaporation crystallization system and refined salt MVR evaporation crystallization system adopt the temperature to evaporate at 60 ~ 70 ℃, except that the steam compressor seals need steam and outside, do not need extra steam to supply, can reach 60-70kwh electric evaporation one ton water.

Finally, the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all of them should be covered by the scope of the claims of the present invention.

Claims

1. The MVR evaporation system for the synergistic resource treatment of the preserved szechuan pickle wastewater is characterized by comprising an advanced oxidation-Fenton pretreatment system (I), a crude salt MVR evaporation crystallization system (II) and a refined salt MVR evaporation crystallization system (III) which are sequentially connected;

advanced oxidation-Fenton pretreatment system (I) is including consecutive raw materials reservoir (3), fenton retort (11), neutralization tank (14) and horizontal decanter centrifuge (19), and wherein Fenton retort (11) are connected with H ₂ O ₂ Storage tank (1A) and FeCl ₂ The device comprises a storage tank (1C), a neutralization tank (14) is connected with a NaOH storage tank (1D) and a compressed air pipe (16), wherein a Fenton reaction tank outlet (12) of a Fenton reaction tank (11) is connected with a neutralization tank inlet (15) of the neutralization tank (14);

the crude salt MVR evaporative crystallization system (II) comprises a crude salt MVR feeding tank (22), a crude salt MVR separator (30) and a crude salt MVR solid-liquid separation centrifuge (28) which are sequentially connected;

the refined salt MVR evaporation crystallization system (III) comprises a crude salt dissolving tank (35), a refined salt MVR feeding tank (36), a refined salt MVR separator (44) and a refined salt MVR solid-liquid separation centrifuge (42) which are sequentially connected;

the device comprises a high-grade oxidation-Fenton pretreatment system (I), a clear liquid outlet (20) of a horizontal screw centrifuge (19) in the high-grade oxidation-Fenton pretreatment system (I) and an inlet of a crude salt MVR feeding tank (22) in a crude salt MVR evaporation crystallization system (II) are connected, an outlet of a crude salt MVR solid-liquid separation centrifuge (28) in the crude salt MVR evaporation crystallization system (II) is respectively connected with an inlet of a crude salt dissolving tank (35) in a town sewage treatment system and a refined salt MVR evaporation crystallization system (III), and an outlet of a refined salt MVR solid-liquid separation centrifuge (42) in the refined salt MVR evaporation crystallization system (III) is connected with the town sewage treatment system.

2. The MVR evaporation system according to claim 1, wherein the top inlet of the Fenton reaction tank (11) comprises H leading into the bottom of the Fenton reaction tank (11) ₂ O ₂ Inlet tube (9) and FeCl ₂ An inlet pipe (10) in which H ₂ O ₂ Inlet pipe (9) and H ₂ O ₂ H is arranged between the storage tanks (1A) ₂ O ₂ Diaphragm pump (2A), feCl ₂ Inlet tube (10) and FeCl ₂ FeCl is arranged between the storage tanks (1C) ₂ A diaphragm pump (2D);

a side inlet on one side of the Fenton reaction tank (11) contains a raw material inlet pipe (8) which is introduced into the bottom of the Fenton reaction tank (11), wherein the raw material inlet pipe (8) is connected with a pipeline mixer (6), a first pH meter (7A) is arranged in the middle of the raw material inlet pipe, the pipeline mixer (6) is respectively connected with an HCl storage tank (1B) and a raw material storage pool (3), a high-grade oxidation feed pump (2C) is arranged between the raw material storage pool (3) and the pipeline mixer (6), the raw material storage pool (3) is provided with a raw material storage pool liquid level meter (4A), and an HCl diaphragm pump (2B) is arranged between the HCl storage tank (1B) and the pipeline mixer (6);

a Fenton reaction tank outlet (12) on the other side of the Fenton reaction tank (11) is connected with a neutralization tank inlet (15) of a neutralization tank (14), and a neutralization tank outlet (18) of the neutralization tank (14) is connected with a horizontal screw centrifuge (19);

the top of the Fenton reaction tank (11) is provided with a first variable frequency stirrer (13A) and a Fenton reaction tank liquid level meter (4B), and the side surface of the Fenton reaction tank (11) is provided with a second pH meter (7B);

the top inlet of the neutralization tank (14) comprises a compressed air pipe (16) and a NaOH pipe (17) which are introduced into the bottom of the neutralization tank (14), wherein the NaOH pipe (17) is connected with a NaOH storage tank (1D) and is provided with a NaOH diaphragm pump (2E);

a second variable-frequency stirrer (13B) and a neutralization tank liquid level meter (4C) are arranged at the top of the neutralization tank (14), and a third pH meter (7C) is arranged in the neutralization tank (14);

the horizontal decanter centrifuge (19) is provided with a solid outlet (21) and a clear liquid outlet (20), the clear liquid outlet (20) of the horizontal decanter centrifuge (19) is connected with a crude salt MVR feeding tank (22) in the crude salt MVR evaporative crystallization system (II), wherein the crude salt MVR feeding tank (22) is provided with a clear liquid tank level meter (4D).

3. The MVR evaporation system according to claim 1, wherein the crude salt MVR separator (30) is composed of an upper crude salt MVR crystallizer (31) and a lower crude salt MVR crystallization leg (32) which are connected, and a crude salt MVR discharge circulation pump (26) is arranged between the crude salt MVR crystallizer (31) and the crude salt MVR crystallization leg (32);

the crude salt MVR crystallizer (31) is respectively connected with the top end and the bottom of a crude salt MVR heater (29), a crude salt MVR forced circulation pump (25) is arranged between the bottom of the crude salt MVR heater (29) and the crude salt MVR crystallizer (31), and the lower part of the crude salt MVR heater (29) is connected with a crude salt MVR condensed water negative pressure pump (24);

the crude salt MVR crystallizer (31) is respectively connected with a crude salt MVR cyclone separator (33) and a crude salt MVR cyclone separator demisting device (34), wherein the crude salt MVR cyclone separator demisting device (34) is communicated with the crude salt MVR cyclone separator (33) positioned right below, and a crude salt MVR vapor compressor (27) is arranged between the crude salt MVR cyclone separator demisting device (34) and the crude salt MVR crystallizer (31);

a crude salt MVR feeding pump (23) is arranged between the crude salt MVR feeding tank (22) and the crude salt MVR crystallizer (31).

4. The MVR evaporation system according to claim 1, characterized in that the refined salt MVR separator (44) consists of an upper refined salt MVR crystallizer (45) and a refined salt MVR crystallization leg (46) located directly below;

a refined salt MVR discharging circulating pump (40) is arranged between the refined salt MVR crystallizer (45) and the refined salt MVR crystallization leg (46);

the refined salt MVR crystallizer (45) is respectively connected with the top end and the bottom of a refined salt MVR heater (43), a refined salt MVR forced circulation pump (39) is arranged between the bottom of the refined salt MVR heater (43) and the refined salt MVR crystallizer (45), and the lower part of the refined salt MVR heater (43) is connected with a refined salt MVR condensed water negative pressure pump (38);

the refined salt MVR crystallizer (45) is respectively connected with a refined salt MVR cyclone separator (47) and a refined salt MVR cyclone separator demisting device (48), wherein the refined salt MVR cyclone separator demisting device (48) is communicated with the refined salt MVR cyclone separator (47) positioned right below, and a refined salt MVR steam compressor (41) is arranged between the refined salt MVR cyclone separator demisting device (48) and the refined salt MVR crystallizer (45);

a liquid level meter (4E) of the crude salt dissolving tank is arranged on the side surface of the crude salt dissolving tank (35), and a third variable frequency stirrer (13C) is arranged at the top of the crude salt dissolving tank;

refined salt MVR feed tank (36) side is provided with refined salt MVR feed tank level gauge (4F), wherein is provided with refined salt MVR charge pump (37) between refined salt MVR feed tank (36) and refined salt MVR crystallizer (45).

5. The MVR evaporation system according to claim 1, wherein the outlet of the crude salt MVR solid-liquid separation centrifuge (28) and the outlet of the fine salt MVR solid-liquid separation centrifuge (42) are respectively connected with the mother liquor inlet (5) of the raw material storage tank (3).