MVR (Mechanical Vapor Recompression) quadruple-effect vacuum evaporative crystallization system
The MVR four-effect vacuum evaporation crystallization system utilizes secondary steam heat to treat high ammonia nitrogen wastewater, solving the problem of high energy consumption in existing technologies and achieving low-energy, high-efficiency wastewater treatment and environmental compliance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHUCHENG DONGXIAO BIOTECH CO LTD
- Filing Date
- 2025-05-16
- Publication Date
- 2026-05-01
AI Technical Summary
Existing technologies for treating high ammonia nitrogen wastewater do not meet standards and consume excessive energy. In particular, after treating high ammonia nitrogen wastewater generated during arginine ion exchange, the ammonia nitrogen content still does not meet emission requirements, and the steam consumption is enormous.
The MVR four-effect vacuum evaporation crystallization system uses sequentially connected components such as a feed pump, plate heat exchanger, preheater, first-effect heater, second-effect heater, third-effect separator, and fourth-effect separator, combined with two MVR fans, to utilize the heat of secondary steam for evaporation, reducing the demand for external energy.
It achieves low-energy consumption treatment of high ammonia nitrogen wastewater, reducing steam consumption to 0.04 tons/ton of wastewater, and the COD and ammonia nitrogen concentrations of condensate meet environmental protection requirements and reach wastewater discharge standards.
Smart Images
Figure CN224185889U_ABST
Abstract
Description
A four-effect vacuum evaporation crystallization system for MVR Technical Field
[0001] This utility model relates to the field of evaporation crystallization technology, and in particular to an MVR four-effect vacuum evaporation crystallization system. Background Technology
[0002] The wastewater generated during the arginine ion exchange process is high-ammonia nitrogen wastewater (ammonia nitrogen about 15,000 mg / L and COD about 11,000 mg / L), and the volume of high-ammonia nitrogen wastewater is very large, about 1,100 tons / day, which is directly discharged into the sewage treatment workshop. Due to the high ammonia nitrogen content, although the existing sewage treatment equipment can reduce the ammonia nitrogen content to a certain extent, the ammonia nitrogen content still does not meet the wastewater discharge requirements.
[0003] In addition, the dry matter content in high ammonia nitrogen wastewater is about 3%, and ammonia nitrogen cannot crystallize out. Therefore, it needs to be evaporated to a dry matter content of more than 50% before crystallization can occur. However, in the existing technology, the steam consumption for treating one ton of high ammonia nitrogen wastewater is about 0.3-0.4 tons, which is a very large energy consumption. Summary of the Invention
[0004] In view of this, this utility model proposes an MVR four-effect vacuum evaporation crystallization system to solve the problem that the treatment of high ammonia nitrogen wastewater in the prior art cannot meet the wastewater discharge requirements and has a very high energy consumption.
[0005] The technical solution of this utility model is implemented as follows:
[0006] This utility model provides an MVR four-effect vacuum evaporation crystallization system, comprising a feed pump, a plate heat exchanger, a preheater, a first-effect heater, a second-effect heater, a third-effect separator, and a fourth-effect separator connected in sequence; the third-effect separator is also connected to the bottom of the third-effect heater, and the top of the third-effect heater is again connected to the third-effect separator; the fourth-effect separator is also connected to the bottom of the fourth-effect heater, and the top of the fourth-effect heater is again connected to the fourth-effect separator; the second-effect heater is also connected to a second separator;
[0007] It also includes a second MVR fan and a first MVR fan; the triple-effect separator and the quadruple-effect separator are respectively connected to the second separator, the second separator is connected to the first MVR fan, the first MVR fan is connected to the second MVR fan, and the second MVR fan is respectively connected to the first-effect heater, the triple-effect heater, and the quadruple-effect heater.
[0008] Based on the above technical solutions, preferably, the second MVR fan is also connected to the pipelines of the single-effect heater, the triple-effect heater, and the quadruple-effect heater, and is also connected to live steam.
[0009] Based on the above technical solutions, preferably, the first-effect heater, the second-effect heater, the third-effect heater, and the fourth-effect heater are connected to the surface condenser and the vacuum pump in sequence.
[0010] Based on the above technical solutions, preferably, the four-effect separator is also sequentially connected to a crystal slurry tank, a centrifuge, a chemical mixing tank, a mother liquor tank, and a mother liquor pump.
[0011] Based on the above technical solutions, preferably, a first separator is also connected between the first-effect heater and the second-effect heater.
[0012] The MVR four-effect vacuum evaporation crystallization system of this invention has the following advantages over the prior art:
[0013] 1. Low overall energy consumption
[0014] The system adopts a four-effect vacuum evaporation system and is equipped with two MVR blowers to make full use of the heat of secondary steam. Based on the calculation of evaporating 70 tons / h of high ammonia nitrogen wastewater, it takes about 0.04 tons of steam to treat 1 ton of high ammonia nitrogen wastewater, which greatly reduces the amount of live steam used.
[0015] 2. Meets environmental protection requirements
[0016] The evaporated condensate has a COD of approximately 1000 mg / L and an ammonia nitrogen of approximately 15 mg / L, which meets environmental protection requirements. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 is a diagram of the MVR four-effect vacuum evaporation crystallization system of this utility model;
[0019] In the diagram: 1-Feed pump, 2-Plate heat exchanger, 3-Preheater, 4-Single-effect heater, 5-Double-effect heater, 6-Triple-effect separator, 7-Triple-effect heater, 8-Quadruple-effect separator, 9-Quadruple-effect heater, 10-Crystal slurry tank, 11-Centrifuge, 12-Chemical feed tank, 13-Mother liquor tank, 14-Mother liquor pump, 15-First separator, 16-Second separator, 17-Second MVR blower, 18-First MVR blower, 19-Surface condenser, 20-Vacuum pump. Detailed Implementation
[0020] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.
[0021] The four-effect vacuum evaporation crystallization system includes a feed pump 1, a plate heat exchanger 2, a preheater 3, a first-effect heater 4, a second-effect heater 5, a third-effect separator 6, a fourth-effect separator 8, a crystal slurry tank 10, a centrifuge 11, a material mixing tank 12, a mother liquor tank 13, and a mother liquor pump 14 connected in sequence. The third-effect separator 6 is also connected to the bottom of the third-effect heater 7, and the top of the third-effect heater 7 is again connected to the third-effect separator 6. The fourth-effect separator 8 is also connected to the bottom of the fourth-effect heater 9, and the top of the fourth-effect heater 9 is again connected to the fourth-effect separator 8. The first-effect heater 4 and the second-effect heater 5 are also connected to a first separator 15, and the second-effect heater 5 is also connected to a second separator 16.
[0022] The wastewater generated during the arginine ion exchange process is fed through a feed pump 1, a plate heat exchanger 2, and a preheater 3, and then sequentially enters a first-effect heater 4 and a second-effect heater 5 for heating to increase the wastewater concentration. Since a first separator 15 is also connected between the first-effect heater 4 and the second-effect heater 5, it can precipitate out the small amount of crystals generated after heating by the first-effect heater 4. The second-effect heater 5 is also connected to a second separator 16, which can precipitate out the small amount of crystals generated after heating by the second-effect heater 5.
[0023] The wastewater passing through the double-effect heater 5 continues to enter the triple-effect separator 6 for crystallization, and then enters the triple-effect heater 7 for further heating. After heating, it is recycled back to the triple-effect separator 6 to further increase the concentration of wastewater, resulting in larger and more numerous crystal particles.
[0024] Wastewater continues to flow from the triple-effect separator 6 into the quadruple-effect separator 8 for crystallization, and then enters the quadruple-effect heater 9 for further heating. After heating, it is recycled back to the quadruple-effect separator 8 to further increase the concentration of wastewater. As the concentration of the solution continues to increase, the crystal particles become larger and more numerous.
[0025] Finally, the ammonia nitrogen in the wastewater has been crystallized out, the wastewater meets the discharge requirements, and is discharged sequentially through the crystal slurry tank 10, centrifuge 11, chemical material tank 12, mother liquor tank 13, and mother liquor pump 14.
[0026] The triple-effect separator 6 and the triple-effect heater 7, and the quadruple-effect separator 8 and the quadruple-effect heater 9 have two cycles, which are forced cycles to prevent the crystallized wastewater from clogging the pipes in the triple-effect separator 6 and the quadruple-effect separator 8.
[0027] The MVR four-effect vacuum evaporation crystallization system of this utility model also includes a second MVR fan 17 and a first MVR fan 18;
[0028] The triple-effect separator 6 and the quadruple-effect separator 8 are respectively connected to the second separator 16. The second separator 16 is connected to the first MVR fan 18. The first MVR fan 18 is connected to the second MVR fan 17. The second MVR fan 17 is respectively connected to the first-effect heater 4, the triple-effect heater 7, and the quadruple-effect heater 9.
[0029] MVR fans are an energy-saving technology that reuses the energy of secondary steam generated by the system itself, thereby reducing the demand for external energy.
[0030] Since the triple-effect separator 6 and the quadruple-effect separator 8 are respectively connected to the second separator 16, the non-condensable steam generated in the two cycles of the triple-effect separator 6 and the triple-effect heater 7, and the quadruple-effect separator 8 and the quadruple-effect heater 9, all enter the second separator 16 for solid-liquid separation. Since the first-effect heater 4 is connected to the second-effect heater 5 through the first separator 15, and the second-effect heater 5 is connected to the second separator 16, the non-condensable steam generated in the first-effect heater 4 and the second-effect heater 5 also enters the second separator 16 for solid-liquid separation. Therefore, the air volume at the second separator 16 is the largest. The second separator 16 is connected to the first MVR fan 18.
[0031] All the non-condensable steam collected by the first MVR blower 18 continues to enter the second MVR blower 17. After being compressed by the two-stage blowers, the temperature of the non-condensable steam increases by 12-14 degrees. The steam with the increased temperature then returns to the first-effect heater 4, the third-effect heater 7, and the fourth-effect heater 9. Thus, the first-effect heater 4, the third-effect heater 7, and the fourth-effect heater 9 do not need to provide additional steam during the process of heating wastewater.
[0032] Furthermore, the second MVR blower 17 is connected to the pipelines of the first-effect heater 4, the third-effect heater 7, and the fourth-effect heater 9, and is also connected to live steam. After the MVR four-effect vacuum evaporation crystallization system has been used for a long time, the compression capacity of the second MVR blower 17 and the first MVR blower 18 may decrease, and the temperature increase of the non-condensable steam may not reach 12-14 degrees. The heat can be supplemented by adding live steam to ensure the heating effect of the first-effect heater 4, the second-effect heater 5, the third-effect heater 7, and the fourth-effect heater 9.
[0033] In this invention, the first-effect heater 4, the second-effect heater 5, the third-effect heater 7, and the fourth-effect heater 9 are sequentially connected to the surface condenser 19 and the vacuum pump 20. The vacuum pump 20 creates a negative pressure in the MVR four-effect vacuum evaporation crystallization system, enabling the system to operate smoothly (to make the circuitry in Figure 1 clearer, the connection lines between the first-effect heater 4, the second-effect heater 5, the third-effect heater 7, the fourth-effect heater 9, and the vacuum pump 20 are not shown).
[0034] The MVR four-effect vacuum evaporation crystallization system of this invention utilizes the heat from steam generated within the system itself for heating, essentially eliminating the need for additional steam supply. Compared to existing evaporation crystallization systems, which require a continuous supply of live steam during heating due to the absence of an internal heat source, this invention significantly saves steam energy. It is suitable for wastewater treatment with low dry matter content, high ammonia nitrogen content, and large wastewater volumes.
[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. An MVR four-effect vacuum evaporation crystallization system, comprising a feed pump (1), a plate heat exchanger (2), a preheater (3), a first-effect heater (4), a second-effect heater (5), a third-effect separator (6), and a fourth-effect separator (8) connected in sequence; the third-effect separator (6) is also connected to the bottom of the third-effect heater (7), and the top of the third-effect heater (7) is again connected to the third-effect separator (6); the fourth-effect separator (8) is also connected to the bottom of the fourth-effect heater (9), and the top of the fourth-effect heater (9) is again connected to the fourth-effect separator (8); the second-effect heater (5) is also connected to a second separator (16); characterized in that: It also includes a second MVR fan (17) and a first MVR fan (18); the triple-effect separator (6) and the quadruple-effect separator (8) are respectively connected to the second separator (16), the second separator (16) is connected to the first MVR fan (18), the first MVR fan (18) is connected to the second MVR fan (17), and the second MVR fan (17) is respectively connected to the first-effect heater (4), the triple-effect heater (7), and the quadruple-effect heater (9).
2. The MVR four-effect vacuum evaporation crystallization system as described in claim 1, characterized in that: The second MVR fan (17) is connected to the pipelines of the single-effect heater (4), the triple-effect heater (7), and the quadruple-effect heater (9), and is also connected to live steam.
3. The MVR four-effect vacuum evaporation crystallization system as described in claim 1, characterized in that: The first-effect heater (4), the second-effect heater (5), the third-effect heater (7), and the fourth-effect heater (9) are connected in sequence to the surface condenser (19) and the vacuum pump (20).
4. The MVR four-effect vacuum evaporation crystallization system as described in claim 1, characterized in that: The four-effect separator (8) is also connected in sequence to the crystal slurry tank (10), centrifuge (11), chemical tank (12), mother liquor tank (13), and mother liquor pump (14).
5. The MVR four-effect vacuum evaporation crystallization system as described in claim 1, characterized in that: A first separator (15) is also connected between the first-effect heater (4) and the second-effect heater (5).