Device for recycling fresh water of electrodialysis reactor to fly ash washing section
By designing a device for recycling freshwater from an electrodialysis reactor to the fly ash washing section, and utilizing a reverse osmosis concentration device and a bypass pipeline, the problem of the inability to directly recycle brine was solved, achieving effective recycling and efficient recovery of brine.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 安徽海螺环保集团有限公司
- Filing Date
- 2025-05-20
- Publication Date
- 2026-04-28
AI Technical Summary
In existing technologies, the brine produced by electrodialysis reactors is difficult to recycle effectively, resulting in the inability to directly recover and utilize the brine in fly ash washing by-product salt high-value system.
By designing a device for recycling freshwater from an electrodialysis reactor to the fly ash washing section, and utilizing a reverse osmosis concentration device and a bypass pipeline, the device can flexibly process the brine according to its chloride ion concentration, either directly reusing or concentrating the brine before reusing it to the fly ash washing section. The concentrated water is used as a supplement to the raw water, thus achieving full recovery of the brine.
This technology enables the effective recycling of brine, reduces the water demand in the fly ash washing section, improves the recovery efficiency of brine, and meets the requirements of the fly ash washing section for low chloride ion content.
Smart Images
Figure CN224172631U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of fly ash treatment technology, specifically relating to a device for recycling freshwater from an electrodialysis reactor to the fly ash washing section. Background Technology
[0002] Current research on the high-value utilization technology of fly ash washing by-product salt involves directly using the mixed brine of sodium chloride and potassium chloride from the MVR (Mechanical Vapor Reduction) system of the fly ash washing system as feedwater for the electrodialysis unit, producing a mixed solution of sodium bicarbonate and potassium bicarbonate. Sodium hydroxide is then added to this mixed solution to generate a mixed solution of sodium carbonate and potassium carbonate, which is directly used for decalcification of the washing solution. However, after ion exchange is used in the system, the electrodialysis unit produces a mixed solution of sodium chloride and potassium chloride. Theoretically, this brine could be considered for recycling and replenishing the original solution or for use in the fly ash washing section. However, as the original solution, the salt concentration needs to be close to that of the raw water, while the fly ash washing section requires process water with the lowest possible salt concentration. Therefore, how to dispose of the brine produced by the electrodialysis reactor is also a problem that needs to be solved in the high-value utilization system of fly ash washing by-product salt. Utility Model Content
[0003] The purpose of this invention is to provide a device for recycling freshwater from an electrodialysis reactor to the fly ash washing section, which solves the technical problem that in the existing fly ash washing by-product salt high-value system, fresh brine is continuously generated at the electrodialysis reactor, but it is currently difficult to effectively recycle the fresh brine.
[0004] The aforementioned device for recycling freshwater from an electrodialysis reactor to a fly ash washing section includes a fly ash washing MVR inlet device, a raw water pretreatment device, an electrodialysis device, a raw water desalination device, a reverse osmosis concentration device, and fly ash washing section equipment. The fly ash washing MVR inlet device is connected to the inlet of the raw water pretreatment device via a pipeline. The raw water pretreatment device is connected to the raw water inlet of the electrodialysis device via a pipeline. The desalinated water overflow port of the electrodialysis device is connected to the raw water desalination device via a pipeline. The concentration port of the reverse osmosis concentration device is connected to a concentrate recovery pipe, while the desalination port is connected to a desalination recovery pipe. The concentrate circulation pipe is connected to the raw water tank of the raw water pretreatment device, and the desalination recovery pipe is connected to the fly ash washing section equipment.
[0005] Preferably, the electrodialysis apparatus is further connected to a storage device for storing ammonium bicarbonate solution and an ammonium bicarbonate desalination device. The storage device is used to input ammonium bicarbonate and convert it into ammonium bicarbonate solution for storage, and to input it into the electrodialysis apparatus as one of the raw materials during the electrodialysis reaction.
[0006] Preferably, the ammonium bicarbonate desalination unit is used to recover the ammonium bicarbonate solution overflowing from the electrodialysis unit, and the overflowing ammonium bicarbonate solution is recovered to the storage unit through pipelines.
[0007] Preferably, the electrodialysis apparatus is further connected to a carbonate device and an ammonium chloride device, which are used to receive and store the carbonate solution and ammonium chloride solution produced by the electrodialysis apparatus, respectively.
[0008] Preferably, the reverse osmosis concentration unit is also equipped with a bypass pipe, the two ends of which are respectively connected to the inlet pipe of the reverse osmosis concentration unit and the fly ash washing section equipment.
[0009] This invention has the following advantages: When the chloride ion concentration in the brine is low enough to be directly applied to fly ash washing, it can be directly applied to fly ash washing via a bypass pipeline. When the chloride ion concentration is high, this solution utilizes a reverse osmosis concentration device to separate the desalinated water and concentrated water. The desalinated water is reused in the upstream fly ash washing section, and the concentrated water is used as raw water supplement, thus allowing the brine to be fully recycled. Attached Figure Description
[0010] Figure 1 This is a schematic diagram of the structure of a device for recycling freshwater from an electrodialysis reactor to the fly ash washing section according to this utility model.
[0011] In the diagram: 1. Electrodialysis unit, 2. Fly ash washing MVR feed water unit, 3. Raw water pretreatment unit, 4. Raw water desalination unit, 5. Reverse osmosis concentration unit, 6. Fly ash washing section equipment, 7. Storage unit, 8. Ammonium bicarbonate desalination unit, 9. Ammonium chloride unit, 10. Carbonate unit, 11. Bypass pipeline, 12. Desalination recovery pipeline, 13. Concentrate recovery pipeline. Detailed Implementation
[0012] The following detailed description of the embodiments, with reference to the accompanying drawings, will further illustrate the specific implementation of this utility model, in order to help those skilled in the art to have a more complete, accurate, and in-depth understanding of the inventive concept and technical solution of this utility model.
[0013] like Figure 1 As shown, this utility model provides a device for recycling freshwater from an electrodialysis reactor to the fly ash washing section. The device includes a fly ash washing MVR inlet device, a raw water pretreatment device 3, an electrodialysis device 1, a raw water desalination device 4, a reverse osmosis concentration device 5, and a fly ash washing section device 6. The fly ash washing MVR inlet device is connected to the inlet of the raw water pretreatment device 3 via a pipeline. The raw water pretreatment device 3 is connected to the raw water inlet of the electrodialysis device 1 via a pipeline. The saline overflow port of the electrodialysis device 1 is connected to the raw water desalination device 4 via a pipeline. The concentration port of the reverse osmosis concentration device 5 is connected to a concentrate recovery pipe 13, while the desalination port is connected to a desalination recovery pipe 12. The concentrate circulation pipe is connected to the raw water tank of the raw water pretreatment device 3, and the desalination recovery pipe 12 is connected to the fly ash washing section device 6.
[0014] The electrodialysis apparatus 1 is also connected to a storage device 7 for storing ammonium bicarbonate solution and an ammonium bicarbonate desalination device 8. The storage device 7 is used to input ammonium bicarbonate and convert it into an ammonium bicarbonate solution for storage, and to input it into the electrodialysis apparatus 1 as one of the raw materials during the electrodialysis reaction. The ammonium bicarbonate desalination device 8 is used to recover the overflowing ammonium bicarbonate solution from the electrodialysis apparatus 1, and to return the overflowing ammonium bicarbonate solution to the storage device 7 through a pipeline.
[0015] The electrodialysis device 1 is also connected to a carbonate device 10 and an ammonium chloride device 9. The carbonate device 10 and the ammonium chloride device 9 are used to receive and store the carbonate solution and ammonium chloride solution produced by the electrodialysis device 1, respectively. The carbonate device 10 is then used to decalcify the fly ash washing liquid.
[0016] The reverse osmosis concentration unit 5 is also equipped with a bypass pipe 11. The two ends of the bypass pipe 11 are connected to the inlet pipe of the reverse osmosis concentration unit 5 and the fly ash washing section equipment 6, respectively. In this way, when the salt concentration of the brine meets the water requirements for fly ash washing, the brine is directly transported to the fly ash washing section equipment 6 via the bypass pipe 11 without being treated by the reverse osmosis concentration unit 5. Otherwise, the brine is treated by the reverse osmosis concentration unit 5 and the resulting fresh water is then transported to the fly ash washing section equipment 6.
[0017] In this invention, the fly ash washing MVR inlet device is used to input and store the fly ash washing solution as raw water. The raw water pretreatment device 3 is used to filter and ion exchange the raw water. The electrodialysis device 1 is used to input raw water and ammonium bicarbonate and then perform an electrodialysis reaction to generate carbonates and ammonium chloride. The raw water desalination device 4 is used to receive the desalinated water produced by the electrodialysis device 1, which also becomes raw water desalination. The reverse osmosis concentration device 5 is used to concentrate the desalinated water to obtain concentrated water with a salt content close to that of the raw water and to separate desalinated water with a lower salt content. The concentrated water is transported through a concentrated water circulation pipe to the pipeline between the raw water pretreatment device 3 and the electrodialysis device 1. The desalinated water is transported through a desalinated water circulation pipe to the fly ash washing section device 6. The reverse osmosis device can be flexibly used according to the chloride ion content in the desalinated water to concentrate and separate the desalinated water, obtaining concentrated water suitable for return to the raw water and desalinated water suitable for fly ash washing.
[0018] Currently, the required chloride ion content in the fly ash after washing should be ≤1%, therefore, the chloride ion content in the water used for fly ash washing should be less than 1%. When the desalination threshold of the raw solution is low, the chloride ion content is less than 1%, which can be directly used as makeup water for the upstream fly ash washing section, reducing the water demand of the fly ash washing section. However, when the desalination threshold is high, the chloride ion content is about 2%. At this time, the reverse osmosis concentration unit 5 separates fresh water with a chloride ion content of less than 1%, which is reused in the upstream fly ash washing section; while the concentrated water has a higher chloride ion content and is used as raw solution supplement, thus solving the problem that the brine cannot be directly recycled due to its unsuitable salt concentration.
[0019] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.
Claims
1. A device for recycling freshwater from an electrodialysis reactor to the fly ash washing section, characterized in that: The system includes a fly ash water washing MVR inlet device, a raw water pretreatment device, an electrodialysis device, a raw water desalination device, a reverse osmosis concentration device, and fly ash water washing section equipment. The fly ash water washing MVR inlet device is connected to the inlet of the raw water pretreatment device via a pipeline. The raw water pretreatment device is connected to the raw water inlet of the electrodialysis device via a pipeline. The saline overflow port of the electrodialysis device is connected to the raw water desalination device via a pipeline. The concentration port of the reverse osmosis concentration device is connected to the concentrate recovery pipe, while the desalination port is connected to the desalination recovery pipe. The concentrate circulation pipe is connected to the raw water tank of the raw water pretreatment device, and the desalination recovery pipe is connected to the fly ash water washing section equipment.
2. The apparatus for recycling freshwater from an electrodialysis reactor to the fly ash washing section according to claim 1, characterized in that: The electrodialysis apparatus is also connected to a storage device for storing ammonium bicarbonate solution and an ammonium bicarbonate desalination device. The storage device is used to input ammonium bicarbonate and convert it into ammonium bicarbonate solution for storage, and to input it into the electrodialysis apparatus as one of the raw materials during the electrodialysis reaction.
3. The apparatus for recycling freshwater from an electrodialysis reactor to the fly ash washing section according to claim 2, characterized in that: The ammonium bicarbonate desalination unit is used to recover the ammonium bicarbonate solution that overflows from the electrodialysis unit, and the overflowing ammonium bicarbonate solution is recovered to the storage unit through pipelines.
4. The apparatus for recycling freshwater from an electrodialysis reactor to the fly ash washing section according to claim 1, characterized in that: The electrodialysis device is also connected to a carbonate device and an ammonium chloride device, which are used to receive and store the carbonate solution and ammonium chloride solution produced by the electrodialysis device, respectively.
5. The apparatus for recycling freshwater from an electrodialysis reactor to the fly ash washing section according to claim 1, characterized in that: The reverse osmosis concentration unit is also equipped with a bypass pipe, the two sections of which are respectively connected to the inlet pipe of the reverse osmosis concentration unit and the fly ash washing section equipment.