Wastewater pretreatment device for MVR (Mechanical Vapor Recompression) evaporator

Abstract

The utility model discloses a wastewater pretreatment device for an MVR (Mechanical Vapor Recompression) evaporator. The wastewater pretreatment device comprises a hardness removal reaction unit, a wastewater collection unit, a dosing unit and a treating fluid transfer unit, the hardness removal reaction unit comprises a reaction tank and a sediment solid discharge port formed in the bottom of the reaction tank; the wastewater collecting unit comprises a wastewater collecting barrel and a first lifting pump which is arranged on the wastewater collecting barrel and is used for sucking wastewater into the reaction tank; the dosing unit comprises a liquid medicine barrel and a dosing pump used for sucking liquid medicine in the liquid medicine barrel into the reaction tank, and the main chemical component of the liquid medicine is one of Na2CO3, NaHCO3 or H2CO3; the treatment liquid transfer unit comprises a treatment liquid transfer barrel and a second lifting pump for sucking the wastewater without hardness in the reaction tank into the treatment liquid transfer barrel. According to the device disclosed by the utility model, calcium and magnesium ions in the wastewater are separated out in a crystal form by adding the carbonic acid soluble salt; and part of crystalline salt remaining in the waste liquid is filtered and removed by the filter for the second time, so that a series of problems caused by scaling of the evaporator are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to a pre-treatment device for high-salt wastewater, which is used to reduce the hardness of wastewater and thus reduce the scaling and fouling of an MVR evaporator. Background Art

[0002] MVR evaporator is used to separate high-salt wastewater through evaporation so that the wastewater can meet the discharge requirements. After evaporation and high-concentration of high-salt wastewater, the salt content increases, and the hardness also increases accordingly. The hardness of wastewater discharge refers to the content of calcium and magnesium ions in the wastewater, also known as the hardness of water.

[0003] Generally, the hardness of water after high concentration is 1000-1500ppm. The scaling ions in the wastewater with higher hardness will precipitate and adhere to the tube wall of the evaporator after evaporation and concentration in the MVR evaporator, forming hard scale that is difficult to fall off. At the very least, the heating efficiency is reduced, resulting in reduced water production efficiency. At worst, the pipeline or device is blocked, resulting in high maintenance costs for the evaporator. Summary of the invention

[0004] In order to overcome the above-mentioned defects, the utility model provides a wastewater pretreatment device for an MVR evaporator. Before the wastewater enters the MVR evaporator, the pretreatment device is used to remove the calcium and magnesium ion content in the wastewater, thereby reducing the hardness of the water, thereby reducing a series of problems caused by scaling ions adhering to the MVR evaporator.

[0005] The utility model adopts a technical solution to solve the technical problem: to provide a wastewater pretreatment device for an MVR evaporator, comprising a hardness removal reaction unit, a wastewater collection unit, a dosing unit, and a treatment liquid transfer unit;

[0006] The hardness removal reaction unit comprises a reaction tank and a solid discharge port arranged at the bottom of the reaction tank for discharging reaction precipitates;

[0007] The wastewater collection unit includes a wastewater collection barrel and a first lifting pump provided on the wastewater collection barrel for sucking wastewater into the reaction tank;

[0008] The dosing unit includes a liquid medicine barrel and a dosing pump for sucking the liquid medicine in the liquid medicine barrel into the reaction tank, and the main chemical component of the liquid medicine is one of Na2CO3, NaHCO3 or H2CO3;

[0009] The treatment liquid transfer unit includes a treatment liquid transfer barrel and a second lift pump for sucking the wastewater from which hardness is removed in the reaction tank into the treatment liquid transfer barrel. The water outlet of the treatment liquid transfer barrel is connected to the MVR evaporator.

[0010] As a further improvement of the utility model, the bottom of the reaction tank is funnel-shaped, the solid discharge port is arranged at the bottom of the funnel, and the solid discharge port is connected to a solid discharge pipeline, and the solid discharge pipeline is provided with a solid discharge control valve.

[0011] As a further improvement of the utility model, the wastewater collection unit further includes a wastewater pipeline, the first lift pump is arranged on the wastewater pipeline, the inlet end of the wastewater pipeline is connected to the wastewater collection bucket, and the outlet end is sealed and connected to the lower interface of the three-way connector A;

[0012] The dosing unit also includes a medicine liquid pipeline, the dosing pump is arranged on the medicine liquid pipeline, the inlet end of the medicine liquid pipeline is communicated with the medicine liquid barrel, and the outlet end is sealed and connected to the upper interface of the three-way connector A;

[0013] The side interface of the three-way connector A is sealed and connected with a pipeline mixer, and the outlet end of the pipeline mixer extends into the reaction tank.

[0014] As a further improvement of the utility model, a first one-way valve and two first control valves are also provided on the wastewater pipeline. The first one-way valve is arranged near the outlet end of the first lifting pump; the two first control valves are respectively arranged near the inlet end of the first lifting pump and the outlet end of the first one-way valve.

[0015] As a further improvement of the utility model, a second one-way valve and two second control valves are also provided on the drug liquid pipeline. The second one-way valve is arranged close to the inlet end of the dosing pump, and the two second control valves are arranged close to the inlet end of the second one-way valve and the outlet end of the dosing pump respectively.

[0016] As a further improvement of the present invention, the treatment liquid transfer unit further comprises a main water outlet pipeline, the second lift pump is arranged on the main water outlet pipeline, the inlet end of the main water outlet pipeline is communicated with the reaction tank, and the outlet end is sealed and connected to the lower interface of the three-way connector B.

[0017] The upper interface of the three-way connector B is connected to the return branch, and the side interface is connected to the outlet branch. The outlet end of the return branch extends into the reaction tank, and the outlet end of the outlet branch is connected to the inlet end of the filter.

[0018] As a further improvement of the utility model, a third one-way valve and two third control valves are further provided on the main water outlet pipeline, the third one-way valve is arranged close to the outlet end of the second lift pump, and the two third control valves are arranged close to the inlet end of the second lift pump and the outlet end of the third one-way valve respectively;

[0019] A fourth control valve is arranged on the water return branch.

[0020] As a further improvement of the utility model, the filter is connected to the treatment liquid transfer barrel through a filtrate pipeline, a flow meter is provided on the filtrate pipeline, and a pressure gauge for detecting the pressure inside the filter is provided on the filter.

[0021] As a further improvement of the utility model, the reaction tank, the wastewater collection barrel and the treatment liquid transfer barrel are respectively provided with liquid level displays.

[0022] The beneficial effects of the utility model are as follows: calcium, magnesium ions and the like in the wastewater are precipitated in the form of carbonates and crystals by adding soluble carbonate salts, and the crystallized salts are discharged through the solid discharge port at the bottom of the reaction tank; and part of the crystallized salts remaining in the waste liquid are removed by secondary filtration through the filter, and the operating cost of the entire device is low, thereby reducing the frequency of scaling and clogging of the tubes when the MVR evaporator carries high-salt wastewater with high hardness during evaporation, solving the problem of reduced heating efficiency and low water production efficiency due to scaling and adhesion of the tubes of the evaporator, and also reducing the maintenance cost of the evaporation system due to blockage and cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the utility model;

[0024] Figure 2 This is a schematic diagram of the wastewater treatment process of the utility model.

[0025] Combined with the accompanying drawings, the following description is given:

[0026] 1. Hardness removal reaction unit; 11. Reaction tank; 111. Solids discharge port; 12. Solids discharge pipeline; 13. Solids discharge control valve; 2. Wastewater collection unit; 21. Wastewater collection barrel; 22. First lifting pump; 23. Wastewater pipeline; 24. First one-way valve; 25. First control valve; 3. Dosing unit; 31. Liquid medicine barrel; 32. Dosing pump; 33. Liquid medicine pipeline; 34. Second one-way valve; 35. Second control valve; 4. Transfer unit; 41. Treatment liquid transfer barrel; 42. Second lifting pump; 43. Main water outlet pipeline; 44. Third one-way valve; 45. Third control valve; 46. Filtrate pipeline; 461. Flow meter; 5. Three-way connector A; 6. Pipe mixer; 7. Three-way connector B; 71. Return branch; 711. Fourth control valve; 72. Water outlet branch; 8. Filter; 81. Pressure gauge; 9. Liquid level display. DETAILED DESCRIPTION

[0027] A preferred embodiment of the present utility model is described in detail below in conjunction with the accompanying drawings.

[0028] See also Figures 1 to 2The utility model provides an embodiment of a wastewater pretreatment device for an MVR evaporator. The wastewater pretreatment device removes the calcium and magnesium ion content in the high-salt and high-hardness wastewater before entering the MVR evaporator, reduces the hardness of the water, thereby reducing the adhesion of scaling ions on the tube wall of the MVR evaporator, and solves the problems of reduced evaporator heating efficiency and low water production efficiency due to scaling adhesion, as well as high maintenance costs caused by high-frequency cleaning of the tubes.

[0029] The wastewater pre-treatment device comprises a hardness removal reaction unit 1, a wastewater collection unit 2, a dosing unit 3, and a treatment liquid transfer unit 4;

[0030] The hardness removal reaction unit 1 comprises a reaction tank 11 and a solid discharge port 111 disposed at the bottom of the reaction tank 11 for discharging reaction precipitates;

[0031] The wastewater collection unit 2 includes a wastewater collection barrel 21, a first lift pump 22 disposed on the wastewater collection barrel 21 for sucking wastewater into the reaction tank 11;

[0032] The dosing unit 3 includes a liquid medicine barrel 31 and a dosing pump 32 for sucking the liquid medicine in the liquid medicine barrel 31 into the reaction tank 11, wherein the main chemical component of the liquid medicine in the liquid medicine barrel 31 is one of Na2CO3, NaHCO3 or H2CO3;

[0033] The treatment liquid transfer unit 4 includes a treatment liquid transfer barrel 41 and a second lift pump 42 for sucking the wastewater from the reaction tank 11 to be de-hardened into the treatment liquid transfer barrel 41. The water outlet of the treatment liquid transfer barrel 41 is connected to the MVR evaporator.

[0034] That is, high-salt and high-hardness wastewater is uniformly collected in the wastewater collection barrel 21 of the wastewater collection unit 2, and sucked into the reaction tank 11 of the hardness removal reaction unit 1 through the first lifting pump 22. At the same time, the dosing pump 32 of the dosing unit 3 sucks liquid medicine from the liquid medicine barrel 31 into the reaction tank 11. At this time, the liquid medicine in the reaction tank reacts with the calcium ions, magnesium ions, etc. in the wastewater to obtain crystalline salts such as CaCO3 and MgCO3. The crystalline salt sinks to the bottom of the reaction tank 11, and the upper part of the reaction tank 11 is the waste liquid after the hardness is removed. The waste liquid is sucked into the treatment liquid transfer barrel 41 for collection through the second lifting pump 42. When the crystallized salt at the bottom of the reaction tank 11 reaches a certain level, the entire device stops operating, and the reaction tank 11 is emptied through the solid discharge port 111.

[0035] In this embodiment, ions that mainly affect hardness, such as calcium and magnesium ions in the wastewater, are precipitated in the form of carbonates and crystals by adding soluble carbonate salts, and the crystallized salts are completely removed from the high-concentration wastewater through the solid discharge port at the bottom of the reaction tank, thereby reducing the frequency of scaling and clogging of the tubes when the MVR evaporator carries high-salt wastewater with high hardness during evaporation, solving the problem of reduced heating efficiency and low water production efficiency due to scaling and adhesion of the tubes of the evaporator, and also reducing the maintenance cost of the evaporation system due to blockage and cleaning.

[0036] Furthermore, the bottom of the reaction tank 11 is funnel-shaped to facilitate the precipitation and collection of crystals. The solid discharge port 111 is arranged at the bottom of the funnel, and the solid discharge port 111 is connected to a solid discharge pipeline 12. The solid discharge pipeline 12 is provided with a solid discharge control valve 13. When the crystals in the reaction tank 11 reach a certain level, the solid discharge control valve 13 is opened to empty the inside of the reaction tank 11, so as to facilitate the next round of reaction operations.

[0037] Furthermore, the wastewater collection unit 2 also includes a wastewater pipeline 23, and the first lifting pump 22 is arranged on the wastewater pipeline 23. The inlet end of the wastewater pipeline 23 is connected to the wastewater collection barrel 21, and the outlet end is sealed and connected to the lower interface of the three-way connector A5; the wastewater pipeline 23 is also provided with a first one-way valve 24 and two first control valves 25 to prevent the backflow of waste liquid, and the first one-way valve 24 is arranged near the outlet end of the first lifting pump 22; the two first control valves 25 are respectively arranged near the inlet end of the first lifting pump 22 and the outlet end of the first one-way valve 24.

[0038] The dosing unit 3 also includes a liquid medicine pipeline 33, a dosing pump 32 is arranged on the liquid medicine pipeline 33, the inlet end of the liquid medicine pipeline 33 is connected to the liquid medicine barrel 31, and the outlet end is sealed and connected to the upper interface of the three-way connector A5; a second one-way valve 34 and two second control valves 35 are also provided on the liquid medicine pipeline 33, the second one-way valve 34 is arranged near the inlet end of the dosing pump 32, and the two second control valves 35 are respectively arranged near the inlet end of the second one-way valve 34 and the outlet end of the dosing pump 32.

[0039] The side interface of the three-way connector A5 is sealed and connected with a pipeline mixer 6 , and the outlet end of the pipeline mixer 6 extends into the reaction tank 11 .

[0040] The wastewater and the liquid medicine simultaneously pass through the pipeline mixer 6 and enter the reaction tank, which can ensure effective mixing and reaction efficiency, thereby removing most of the calcium ions and part of the magnesium ions.

[0041] Further, the treatment liquid transfer unit 4 also includes a main water outlet pipeline 43, a second lift pump 42 is arranged on the main water outlet pipeline 43, the inlet end of the main water outlet pipeline 43 is connected to the reaction tank 11, the outlet end is sealed and connected to the lower interface of the three-way connector B7, the upper interface of the three-way connector B7 is connected to the return water branch 71, the side interface is connected to the outlet water branch 72, the outlet end of the return water branch 71 extends into the reaction tank 11, and the outlet end of the outlet water branch 72 is connected to the inlet of the filter 8. A third one-way valve 44 and two third control valves 45 are also arranged on the main water outlet pipeline 43, the third one-way valve 44 is arranged near the outlet end of the second lift pump 42, and the two third control valves 45 are arranged near the inlet end of the second lift pump 42 and the outlet end of the third one-way valve 44 respectively; a fourth control valve 711 is arranged on the return water branch 71.

[0042] The filter 8 is connected to the treated liquid transfer barrel 41 through a filtrate pipeline 46, and a flow meter 461 is provided on the filtrate pipeline 46. The filter 8 is provided with a pressure gauge 81 for detecting the pressure inside the filter. The filtering condition of the filter element of the filter 8 can be known through the pressure display of the pressure gauge 81, so that the filter element can be replaced in time to improve the filtering and water filtering effects.

[0043] Among them, the setting of the return branch 71 is used to return a part of the waste liquid extracted by the second lifting pump 42 to the reaction tank 11, so as to achieve the purpose of balancing the water volume and maintaining constant water quality, while the other part of the waste liquid is filtered through the filter 8 and enters the treated liquid transfer barrel 41. During the filtration process, the crystalline salts such as CaCO3 and MgCO3 remaining in the waste liquid will be enriched and intercepted on the surface of the filter element, and some of the crystals remaining in the waste liquid can be removed by replacing the filter element of the filter 8.

[0044] In addition, in order to understand the status of the liquid in the reaction tank 11, the wastewater collection barrel 21 and the treatment liquid transfer barrel 41 in real time, a liquid level display 9 is provided on the above containers to monitor the status of the liquid storage amount in each container in real time.

[0045] In summary, the utility model provides a wastewater pretreatment device for an MVR evaporator, which precipitates calcium, magnesium ions, etc. in the wastewater in the form of carbonates and crystals by adding soluble carbonate salts, and discharges the crystallized salts through the solid discharge port at the bottom of the reaction tank; and some of the crystallized salts remaining in the waste liquid are removed by secondary filtration through the filter, and the operating cost of the entire device is low, thereby reducing the frequency of scaling and clogging of the tubes when the MVR evaporator carries high-salt wastewater with high hardness during evaporation, solving the problem of reduced heating efficiency and low water production efficiency due to scaling and adhesion of the tubes of the evaporator, and also reducing the maintenance cost of the evaporation system due to blockage and cleaning.

[0046] Many specific details are described in the above description to facilitate a full understanding of the present invention. However, the above description is only a preferred embodiment of the present invention. The present invention can be implemented in many other ways different from those described herein, so the present invention is not limited by the specific implementation disclosed above. At the same time, any person familiar with the technical field can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. A wastewater pretreatment device for an MVR evaporator, characterized in that: It comprises a hardness removal reaction unit (1), a wastewater collection unit (2), a dosing unit (3), and a treatment liquid transfer unit (4); The hardness removal reaction unit (1) comprises a reaction tank (11) and a solids discharge port (111) arranged at the bottom of the reaction tank (11) for discharging reaction precipitates; The wastewater collection unit (2) comprises a wastewater collection barrel (21), and a first lift pump (22) provided on the wastewater collection barrel (21) and used for sucking wastewater into the reaction tank (11); The dosing unit (3) comprises a drug liquid barrel (31) and a drug dosing pump (32) for sucking the drug liquid in the drug liquid barrel (31) into the reaction pool (11), and the chemical composition of the drug liquid is one of Na2CO3, NaHCO3 or H2CO3; The treatment liquid transfer unit (4) comprises a treatment liquid transfer barrel (41) and a second lift pump (42) for sucking the waste liquid from which hardness is removed in the reaction tank (11) into the treatment liquid transfer barrel (41), and the water outlet of the treatment liquid transfer barrel (41) is connected to the MVR evaporator.

2. The wastewater pretreatment device for MVR evaporator according to claim 1, characterized in that: The bottom of the reaction pool (11) is funnel-shaped, the solid discharge port (111) is arranged at the bottom of the funnel, and the solid discharge port (111) is connected to a solid discharge pipeline (12), and a solid discharge control valve (13) is arranged on the solid discharge pipeline (12).

3. The wastewater pretreatment device for MVR evaporator according to claim 1, characterized in that: The wastewater collection unit (2) further comprises a wastewater pipeline (23), the first lift pump (22) being arranged on the wastewater pipeline (23), the inlet end of the wastewater pipeline (23) being in communication with the wastewater collection bucket (21), and the outlet end being sealingly connected to the lower interface of the three-way connector A (5); The dosing unit (3) further comprises a drug liquid pipeline (33), the drug dosing pump (32) is arranged on the drug liquid pipeline (33), the inlet end of the drug liquid pipeline (33) is connected to the drug liquid barrel (31), and the outlet end is sealedly connected to the upper interface of the three-way connector A (5); The side interface of the three-way connector A (5) is sealedly connected to a pipeline mixer (6), and the outlet end of the pipeline mixer (6) extends into the reaction tank (11).

4. The wastewater pretreatment device for MVR evaporator according to claim 3, characterized in that: The wastewater pipeline (23) is further provided with a first one-way valve (24) and two first control valves (25); the first one-way valve (24) is arranged close to the outlet end of the first lift pump (22); and the two first control valves (25) are arranged close to the inlet end of the first lift pump (22) and the outlet end of the first one-way valve (24), respectively.

5. The wastewater pretreatment device for MVR evaporator according to claim 3, characterized in that: The liquid medicine pipeline (33) is also provided with a second one-way valve (34) and two second control valves (35); the second one-way valve (34) is arranged close to the inlet end of the dosing pump (32); and the two second control valves (35) are arranged close to the inlet end of the second one-way valve (34) and the outlet end of the dosing pump (32), respectively.

6. The wastewater pretreatment device for MVR evaporator according to claim 3, characterized in that: The treated liquid transfer unit (4) further comprises a main water outlet pipeline (43), the second lift pump (42) being arranged on the main water outlet pipeline (43), the inlet end of the main water outlet pipeline (43) being in communication with the reaction tank (11), and the outlet end being sealedly connected to the lower interface of the three-way connector B (7); The upper interface of the three-way connector B (7) is connected to the return branch (71), and the side interface is connected to the outlet branch (72). The outlet end of the return branch (71) extends into the reaction tank (11), and the outlet end of the outlet branch (72) is connected to the inlet end of the filter (8).

7. The wastewater pretreatment device for MVR evaporator according to claim 6, characterized in that: The main water outlet pipeline (43) is further provided with a third one-way valve (44) and two third control valves (45); the third one-way valve (44) is arranged close to the outlet end of the second lift pump (42); and the two third control valves (45) are arranged close to the inlet end of the second lift pump (42) and the outlet end of the third one-way valve (44), respectively. The water return branch (71) is provided with a fourth control valve (711).

8. The wastewater pretreatment device for MVR evaporator according to claim 7, characterized in that: The filter (8) is connected to the treated liquid transfer barrel (41) via a filtrate pipeline (46), a flow meter (461) is provided on the filtrate pipeline (46), and a pressure gauge (81) for detecting the pressure inside the filter is provided on the filter (8).

9. The wastewater pretreatment device for MVR evaporator according to claim 1, characterized in that: The reaction pool (11), the wastewater collection barrel (21) and the treatment liquid transfer barrel (41) are respectively provided with a liquid level display (9).

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