MVR (mechanical vapor recompression) fixed discharge process system with COD (chemical oxygen demand) on-line detection function

Abstract

The utility model discloses an MVR (Mechanical Vapor Recompression) fixed-discharge process system with an on-line COD (Chemical Oxygen Demand) detection function, and aims to provide an MVR fixed-discharge process system capable of detecting COD at any time. According to the technical scheme, the MVR fixed-discharge process system is characterized by comprising a feed port, a preheater is connected onto the feed port, a detection device is connected onto the preheater, a gas-liquid separator is further connected onto the preheater, and the gas-liquid separator is connected onto the detection device. The gas-liquid separator is connected with a compressor, the compressor is connected with an evaporator, the evaporator is connected with a preheater, and the preheater is further connected with a condensate water outlet. The detection device comprises a first COD (Chemical Oxygen Demand) water quality sensor and a second COD water quality sensor; the first COD water quality sensor is positioned on one side of the preheater, which is positioned at the feeding hole; and the second COD water quality sensor is positioned on the preheater, which is close to the condensed water outlet end.

Description

Technical Field

[0001] The utility model relates to the field of wastewater treatment equipment, in particular to an MVR fixed discharge process system with online COD detection. Background Art

[0002] Concentration, the core process for resource-based treatment of high-salinity wastewater, is categorized into thermal concentration and membrane concentration, depending on the treatment target and scope of application. Thermal concentration technology is suitable for treating wastewater with high TDS and COD levels of up to several hundred grams per liter. It achieves a high concentration of ions in high-salinity wastewater through heating. It primarily includes multi-stage flash evaporation (MSF), multi-effect evaporation (MED), and mechanical vapor recompression (MVR).

[0003] Mechanical vapor recompression (MVR) utilizes the secondary steam generated by the evaporation system and its energy to upgrade low-quality steam into a high-quality steam heat source through the mechanical work of the compressor. This cycle provides heat energy to the evaporation system, reducing the demand for external energy.

[0004] At present, the Chinese patent publication number CN108128961A discloses a method and system for zero discharge of saline wastewater, including the use of lime-soda ash softening method and dissolved air flotation filtration to further remove hardness and silicon from desuspended matter and decolloided matter; deep removal of hardness through ion exchange; deep treatment of RO concentrate using a combination of advanced oxidation and high-salt microorganisms to further reduce COD, NO3- and NF membrane salt separation process; use of multi-effect MVR for constant temperature evaporation crystallization process to concentrate and separate salt, the MVR discharge concentrate enters before catalytic oxidation or before NF membrane, or all enters the mixed salt MVR to produce all mixed salt; the mother liquor discharged from the MVR device enters the low-temperature freezing method to produce more thenardite to eliminate COD interference, and the frozen liquid undergoes advanced oxidation to eliminate COD in the mother liquor discharged from the crystallization device.

[0005] Although this zero-discharge method and system for saline wastewater has efficient and stable pretreatment technology, and the membrane concentration pretreatment, NF membrane pre-salting and reverse osmosis membrane concentration technologies are energy-saving and reliable, with high overall product water and finished salt yields and energy-saving technologies that reduce the yield of impurity salts, it is often impossible to monitor COD changes online. Summary of the Invention

[0006] The purpose of the utility model is to provide an MVR fixed discharge process system with online COD detection, which has the advantage of being able to detect and monitor the COD content of the entire system inlet and outlet at any time during the working process.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions:

[0008] An MVR fixed-discharge process system with online COD detection includes a feed inlet, the feed inlet is connected to a preheater, the preheater is connected to a detection device, the preheater is also connected to a gas-liquid separator, the gas-liquid separator is connected to a compressor, the compressor is connected to an evaporator, the evaporator is connected to the preheater, and the preheater is also connected to a condensate outlet. The detection device includes a first COD water quality sensor provided on the side of the preheater at the feed inlet and a second COD water quality sensor provided on the preheater near the condensate outlet.

[0009] Further configuration: The gas-liquid separator is also connected to a waste device, the gas-liquid separator is connected to a preheater, the waste device also includes a discharge pump connected to the gas-liquid separator, the discharge pump is connected to a concentrating dryer, and the concentrating dryer is connected to the gas-liquid separation device through a one-way pipe.

[0010] Further configuration: a third COD water quality sensor is also provided on the one-way pipe.

[0011] It is further configured that the condensed water outlet is also provided with a circulation pump, and the outlet of the circulation pump is connected to the feed inlet.

[0012] Further configuration: a solenoid valve is also provided on the outlet of the circulation pump.

[0013] Further configuration: the gas-liquid separator is also provided with a forced pump connected to the evaporator.

[0014] In summary, the present invention has the following beneficial effects: it can effectively detect and monitor the COD content of the MVR fixed discharge system at any time during operation, and at the same time, the process treatment can be repeated if the condensate outlet does not meet the standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below with reference to the accompanying drawings.

[0016] Figure 1 This is a flow chart of the MVR fixed-discharge process system with online COD detection.

[0017] Figure 1 , feed inlet; 2. Preheater; 3. Detection device; 31. First COD water quality sensor; 32. Second COD water quality sensor; 4. Gas-liquid separator; 5. Compressor; 6. Evaporator; 7. Condensate outlet; 8. Waste device; 81. Discharge pump; 82. Concentrator dryer; 83. One-way pipe; 9. Third COD water quality sensor; 10. Circulation pump; 11. Solenoid valve; 12. Forced pump. DETAILED DESCRIPTION

[0018] The specific implementation of the present utility model will be further described below with reference to the accompanying drawings.

[0019] The technical solution adopted by the present invention is: an MVR fixed-discharge process system with online COD detection, including a feed port 1, a preheater 2 connected to the feed port 1, a detection device 3 connected to the preheater 2, the inlet of the preheater 2 is connected to the feed port 1, and the outlet on the other side is connected to the condensate outlet 7, the condensate outlet 7 is also provided with a circulating pump 10, and a solenoid valve 11 is also provided on the outlet of the circulating pump 10, the outlet of the circulating pump 10 is connected to the feed port 1, and the detection device 3 includes a first COD water quality sensor 31 provided on the side of the preheater 2 located on the feed port 1 and a second COD water quality sensor 32 provided on the end of the preheater 2 near the condensate outlet 7.

[0020] The preheater 2 is also connected to a gas-liquid separator 4, the gas-liquid separator 4 is connected to a compressor 5, the compressor 5 is connected to an evaporator 6, the evaporator 6 is connected to the preheater 2, the gas-liquid separator 4 is also provided with a forced pump 12 connected to the evaporator 6, the gas-liquid separator 4 is also connected to a waste device 8, and the gas-liquid separator 4 is connected to the preheater 2, and the waste device 8 also includes a discharge pump 81 connected to the gas-liquid separator 4, the discharge pump 81 is connected to a concentrating dryer 82, the concentrating dryer 82 is connected to the gas-liquid separation device through a one-way pipe 83, and the one-way pipe 83 is also provided with a third COD water quality sensor 9.

[0021] Its main working principle is as follows: During use, wastewater enters the preheater 2 through the feed port 1 for preheating, and then enters the gas-liquid separator 4 for gas-liquid separation. The separated water vapor passes through the evaporator 6 and then passes through the preheater 2 for heat exchange with the wastewater from the feed port 1 to finally form condensed water and be discharged. During this process, the first COD water quality sensor 31 and the second COD water quality sensor 32 can detect the COD content in the feed port 1 and the condensed water at any time. If it does not meet the requirements, the condensed water will be re-entered into the feed port 1 through the circulation pump 10 and the above process will be repeated. The liquid produced during the evaporation process of the evaporator 6 will be separated again through the gas-liquid separator 4 and then enter the evaporator 6 for circulation. Some of the water in the waste liquid separated by the gas-liquid separator 4 will also be dried by the concentrating dryer 82, and the excess water will re-enter the gas-liquid separator 4 for separation.

[0022] The above are only preferred embodiments of the present invention and do not constitute any form of limitation to the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention fall within the scope of the technical solution of the utility model.

Claims

1. An MVR fixed discharge process system with online COD detection, comprising a feed inlet (1), characterized in that: The feed port (1) is connected to a preheater (2), the preheater (2) is connected to a detection device (3), the preheater (2) is also connected to a gas-liquid separator (4), the gas-liquid separator (4) is connected to a compressor (5), the compressor (5) is connected to an evaporator (6), the evaporator (6) is connected to the preheater (2), and the preheater (2) is also connected to a condensate outlet (7). The detection device (3) comprises a first COD water quality sensor (31) provided on the side of the preheater (2) located at the feed port (1), and a second COD water quality sensor (32) provided on the end of the preheater (2) close to the condensate outlet (7).

2. The MVR discharge process system with online COD detection according to claim 1, characterized in that: The gas-liquid separator (4) is also connected to a waste device (8), the gas-liquid separator (4) is connected to the preheater (2), the waste device (8) further includes a discharge pump (81) connected to the gas-liquid separator (4), the discharge pump (81) is connected to a concentrating dryer (82), and the concentrating dryer (82) is connected to the gas-liquid separator via a one-way pipe (83).

3. The MVR discharge process system with online COD detection according to claim 2, characterized in that: A third COD water quality sensor (9) is also provided on the one-way pipe (83).

4. The MVR discharge process system with online COD detection according to claim 3 is characterized in that: The condensed water outlet (7) is further provided with a circulation pump (10), and the outlet of the circulation pump (10) is connected to the feed port (1).

5. The MVR discharge process system with online COD detection according to claim 4 is characterized in that: A solenoid valve (11) is also provided at the outlet of the circulation pump (10).

6. The MVR fixed discharge process system with online COD detection according to claim 5, characterized in that: The gas-liquid separator (4) is also provided with a forced pump (12) connected to the evaporator (6).

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