Brine refining system

Abstract

The utility model provides a brine refining system, which belongs to the technical field of water treatment and comprises a precipitation reaction tank, a crude brine filter, a ceramic membrane filter, an ammonia removal tower, a sodium hydroxide solution inflow pipeline communicated with the precipitation reaction tank and a sodium carbonate solution inflow pipeline communicated with the precipitation reaction tank, the precipitation reaction tank, the crude brine filter and the ammonia removal tower are sequentially communicated along the flowing direction of the brine. According to the utility model, after the ammonia removal tower is arranged behind the ceramic membrane filter, calcium carbonate crystal precipitates and magnesium hydroxide colloidal precipitates are filtered out in the ceramic membrane filter and then are subjected to ammonia removal, so that the calcium carbonate crystal precipitates and the magnesium hydroxide colloidal precipitates are prevented from being deposited on the surface of a packing layer of the ammonia removal tower; the technical problem of scaling of the packing layer of the ammonia removal tower is solved.

Description

Technical Field

[0001] This utility model belongs to the field of water treatment technology, and relates to industrial brine treatment technology, specifically a brine refining system. Background Technology

[0002] The chlor-alkali industry utilizes the electrolysis of saturated brine solutions to produce caustic soda (sodium hydroxide) and chlorine gas, with hydrogen gas as a byproduct. The brine solution is produced through brine (or brine) refining. The brine refining process involves dissolving solid salt in water to obtain saturated brine, or brine from underground salt wells. Sodium carbonate and sodium hydroxide are added at approximately 60°C, causing them to react with calcium and magnesium impurities in the brine to form precipitates such as calcium carbonate and magnesium hydroxide. See patent application number CN202011340631.X, which discloses a method for refining brine in a primary caustic soda refining process using an ion-exchange membrane. This method involves adding sodium carbonate to saturated brine to react with calcium ions to form calcium carbonate, and adding sodium hydroxide to react with magnesium ions to form magnesium hydroxide. The brine is then directly filtered using a flat-plate ceramic membrane to obtain a primary refined brine that meets the requirements for secondary caustic soda refining using an ion-exchange membrane, wherein calcium and magnesium ions are ≤1 mg / L and suspended solids are ≤1 NTU.

[0003] To improve the quality of refined brine, ammonia removal is also required. However, calcium carbonate precipitates and magnesium hydroxide suspensions will deposit on the surface of the packing layer of the ammonia removal equipment, causing scaling, blocking the reaction channels formed by the packing layer, and reducing the throughput of the reaction channels. Utility Model Content

[0004] In response to the aforementioned technical problem, where calcium carbonate precipitates and magnesium hydroxide suspensions generated during the existing brine refining process deposit on the surface of the packing layer in the ammonia removal equipment, causing scaling and resulting in a decrease in the throughput of the reaction channels formed by the packing layer, this invention proposes a brine refining system.

[0005] This invention places the ammonia removal equipment after the ceramic membrane filter. The ceramic membrane filter can remove solid particles larger than 50nm (particles of substances such as calcium carbonate precipitate and magnesium hydroxide suspension), preventing calcium carbonate precipitate and magnesium hydroxide suspension from depositing on the surface of the packing layer of the ammonia removal equipment, thus solving the technical problem of scaling in the packing layer of the ammonia removal equipment.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0007] A brine refining system includes a sedimentation reaction tank, a coarse brine filter, a ceramic membrane filter, an ammonia removal tower, and a sodium hydroxide solution inflow pipe connected to the sedimentation reaction tank and a sodium carbonate solution inflow pipe connected to the sedimentation reaction tank. The sedimentation reaction tank, the coarse brine filter, the ceramic membrane filter, and the ammonia removal tower are connected sequentially along the flow direction of the brine.

[0008] Furthermore, the brine refining system also includes an ammonia removal reaction tank, and the ceramic membrane filter is connected to the ammonia removal tower through the ammonia removal reaction tank. The ammonia removal reaction tank is connected to a sodium hypochlorite solution inflow pipe and a hydrochloric acid solution inflow pipe.

[0009] Furthermore, the brine refining system also includes a ceramic membrane filter, which is connected to a feed brine pipe and a filter brine pipe. The coarse brine filter is connected to the ceramic membrane filter through the feed brine pipe, and the ceramic membrane filter is connected to the ammonia removal reaction tank through the discharge brine pipe.

[0010] Furthermore, the ceramic membrane filter is also connected to a secondary filtration pipe, and the ceramic membrane filter is connected to the feed brine pipe through the secondary filtration pipe.

[0011] Furthermore, the brine refining system also includes a salt mud tank, and the ceramic membrane filter is connected to a concentrated brine pipe, which is connected to the salt mud tank.

[0012] Furthermore, the brine refining system also includes a heat exchange station, which is connected to the sedimentation reaction tank.

[0013] Furthermore, the brine refining system also includes a security filter, and the ammonia removal tower is connected to the security filter.

[0014] Furthermore, a booster pump is installed between the sedimentation reaction tank and the coarse brine filter.

[0015] Furthermore, a first regulating valve is installed on the connecting pipe between the heat exchange station and the sedimentation reaction tank.

[0016] Further specifying, the brine filter pipes are arranged in three stages side by side, with one end of each stage connected to a ceramic membrane filter and the other end connected to an ammonia removal reaction tank, and each stage of the brine filter pipe is equipped with a second regulating valve.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0018] 1. This utility model discloses a brine refining system, which includes an ammonia removal tower positioned after a ceramic membrane filter. Sodium carbonate reacts with calcium ions in the crude brine to form calcium carbonate crystals, while sodium hydroxide reacts with magnesium ions in the crude brine to form magnesium hydroxide colloidal precipitates. The ceramic membrane filter removes solid particles larger than 50 nm. The calcium carbonate crystals and magnesium hydroxide colloidal precipitates are filtered out in the crude brine filter, preventing their deposition on the packing layer of the ammonia removal tower and thus avoiding scaling.

[0019] 2. The brine refining system of this utility model also includes an ammonia removal reaction tank. Sodium hypochlorite solution and hydrochloric acid solution are introduced into the ammonia removal reaction tank to control the free chlorine content at 80ppm and adjust the pH to 9. The solution is then sent to the top of the ammonia removal tower for spraying through the ammonia removal tower feed pump to remove ammonium salts from the brine and improve the quality of the brine treatment.

[0020] 3. This utility model also has a secondary filtration pipe connected to the ceramic membrane filter. The concentrated brine filtered by the ceramic membrane filter can be sent back to the ceramic membrane filter for filtration again through the secondary filtration pipe, and brine can be filtered out again from the filtered salt mud, thereby improving the utilization rate of demineralized water.

[0021] 4. The brine refining system of this utility model also includes a salt mud tank, through which the filtered concentrated brine is collected.

[0022] 5. The brine refining system of this utility model also includes a heat exchange station, which heats the crude brine to a suitable reaction temperature for the substances in the sedimentation reaction tank.

[0023] 6. The brine refining system of this utility model also includes a security filter, which filters the brine after ammonia removal, removes the broken parts of the packing material in the brine, and finally adds sodium sulfite to reduce the excess free chlorine in the brine to obtain qualified brine. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the brine refining system of this utility model;

[0025] Among them, 1-heat exchange station, 2-first regulating valve, 3-sedimentation reaction tank, 4-coarse brine filter, 5-ceramic membrane filter, 6-salt mud tank, 7-ammonia removal reaction tank, 8-ammonia removal tower, 9-security filter. Detailed Implementation

[0026] The technical solution of this utility model will be further explained and described below with reference to the accompanying drawings and embodiments, but this utility model is not limited to the embodiments described below.

[0027] Example 1

[0028] See Figure 1 This embodiment discloses a brine refining system, comprising a sedimentation reaction tank 3, a coarse brine filter 4, a ceramic membrane filter 5, an ammonia removal tower 8, and a sodium hydroxide solution inflow pipe connected to the sedimentation reaction tank 3 and a sodium carbonate solution inflow pipe connected to the sedimentation reaction tank 3. The sedimentation reaction tank 3, coarse brine filter 4, ceramic membrane filter 5, and ammonia removal tower 8 are sequentially connected along the brine flow direction. Specifically, in this embodiment, the outlet of the sedimentation reaction tank 3 is connected to the inlet of the coarse brine filter 4, the outlet of the coarse brine filter 4 is connected to the inlet of the ceramic membrane filter 5, and the outlet of the ceramic membrane filter 5 is connected to the inlet of the ammonia removal tower 8. The outlets of both the sodium carbonate solution inflow pipe and the sodium hydroxide solution inflow pipe are connected to the sedimentation reaction tank 3.

[0029] The working principle of this embodiment is as follows: Sodium carbonate solution and sodium hydroxide solution are introduced into the precipitation reaction tank 3. In the precipitation reaction tank 3, sodium carbonate reacts with calcium ions in crude brine to form calcium carbonate crystal precipitate, and sodium hydroxide reacts with magnesium ions in crude brine to form magnesium hydroxide colloidal precipitate. Solid particles larger than 50nm are removed by a ceramic membrane filter, that is, calcium carbonate crystal precipitate and magnesium hydroxide colloidal precipitate are filtered out by the ceramic membrane filter, so as to avoid the deposition of calcium carbonate crystal precipitate and magnesium hydroxide colloidal precipitate on the packing layer surface of the ammonia removal tower, thereby achieving the effect of avoiding scaling of the packing layer of the ammonia removal tower.

[0030] Example 2

[0031] This embodiment of a brine refining system, based on Embodiment 1, further includes an ammonia removal reaction tank 7. A ceramic membrane filter 5 is connected to an ammonia removal tower 8 via the ammonia removal reaction tank 7. A sodium hypochlorite solution inflow pipe and a hydrochloric acid solution inflow pipe are connected to the ammonia removal reaction tank 7. Specifically, in this embodiment, the outlet of the ceramic membrane filter 5 is connected to the inlet of the ammonia removal reaction tank 7, and the outlet of the ammonia removal reaction tank 7 is connected to the inlet of the ammonia removal tower 8.

[0032] In this embodiment, the ammonia removal tower 8 is equipped with a bottom solution chamber, a feed pump, and a top spray device. The bottom solution chamber is connected to the top spray device through the feed pump.

[0033] This embodiment describes a brine refining system. Sodium hypochlorite solution is added to the ammonia removal reaction tank 7 through a sodium hypochlorite inflow pipe to control the free chlorine content at 80 ppm. Hydrochloric acid solution is then added to the ammonia removal reaction tank 7 through a hydrochloric acid inflow pipe to adjust the pH to 9. The brine after reaction in the solution chamber at the bottom of the ammonia removal tower is sent to the top of the ammonia removal tower by the ammonia removal tower feed pump for spraying. A blower installed at the top of the ammonia removal tower blows away the ammonia.

[0034] Example 3

[0035] This embodiment of a brine refining system, based on Embodiment 2, further includes a ceramic membrane filter 5. The ceramic membrane filter 5 is connected to a feed brine pipe and a filter brine pipe. A coarse brine filter 4 is connected to the ceramic membrane filter 5 via the feed brine pipe, and the ceramic membrane filter 5 is connected to the ammonia removal reaction tank 7 via the filter brine pipe. Specifically, in this embodiment, the outlet of the coarse brine filter 4 is connected to the inlet of the feed brine pipe, the outlet of the feed brine pipe is connected to the inlet of the ceramic membrane filter 5, the outlet of the ceramic membrane filter 5 is connected to the inlet of the filter brine pipe, and the outlet of the filter brine pipe is connected to the inlet of the ammonia removal reaction tank 7.

[0036] In this embodiment, the ceramic membrane filter 5 is also connected to a secondary filtration pipe, which is connected to the feed brine pipe. Specifically, the concentrated brine outlet of the ceramic membrane filter 5 is connected to the inlet of the secondary filtration pipe, and the outlet of the secondary filtration pipe is connected to the feed brine pipe.

[0037] Preferably, in this embodiment, the brine filter pipes are arranged in three stages side by side. One end of each brine filter pipe is connected to the ceramic membrane filter 5, and the other end of each brine filter pipe is connected to the ammonia removal reaction tank 7. Each brine filter pipe is equipped with a second regulating valve.

[0038] The brine refining system in this embodiment also includes a salt mud tank 6, and a concentrated brine pipe is connected to the ceramic membrane filter 5. The ceramic membrane filter 5 is connected to the salt mud tank 6 through the concentrated brine pipe. The outlet of the concentrated brine from the ceramic membrane filter 5 is connected to the inlet of the salt mud pipe, and the outlet of the concentrated brine pipe is connected to the inlet of the salt mud tank 6.

[0039] In this embodiment, the ceramic membrane filter 5 has a three-stage filtration assembly. Each stage of the filtration assembly filters brine and discharges it at a set flow rate. The concentrated brine from the first stage enters the second and third stages for filtration. The concentrated brine discharged from the third stage enters the salt mud tank 6 in a certain proportion and concentration, while the remainder is returned to each stage of the filtration assembly for further filtration through a secondary filtration pipe, thereby improving the filtration effect of impurities.

[0040] Example 4

[0041] This embodiment of a brine refining system, based on embodiment 3, further includes a heat exchange station 1, which is connected to a sedimentation reaction tank 3. Specifically, the outlet of the heat exchange station 1 is connected to the inlet of the sedimentation reaction tank 3. The crude brine from the brine collection and transportation device is heated to 55-65°C via the heat exchange station 1, thus heating the crude brine to a suitable reaction temperature for the substances in the sedimentation reaction tank 3.

[0042] In this embodiment, a first regulating valve 2 is provided between the heat exchange station 1 and the sedimentation reaction tank 3.

[0043] This embodiment provides a brine refining system, which also includes a security filter 9, and an ammonia removal tower 8 connected to the security filter 9. The brine outlet of the ammonia removal tower 8 is connected to the inlet of the security filter 9. The brine after ammonia removal passes through the broken parts of the filter media in the security filter 9, and finally sodium sulfite is added to reduce the excess free chlorine in the primary brine to obtain qualified brine.

[0044] Preferably, in this embodiment, a booster pump is provided between the sedimentation reaction tank 3 and the coarse brine filter 4. The booster pump pressurizes the coarse brine after reaction in the sedimentation reaction tank 3 and transports it to the coarse brine filter 4 for filtration.

[0045] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A brine refining system, characterized by, The brine refining system comprises a precipitation reaction tank (3), a coarse brine filter (4), a ceramic membrane filter (5), an ammonia removal tower (8), and a sodium hydroxide solution inflow pipe and a sodium carbonate solution inflow pipe in communication with the precipitation reaction tank (3), wherein the precipitation reaction tank (3), the coarse brine filter (4), the ceramic membrane filter (5), and the ammonia removal tower (8) are sequentially communicated in the flow direction of the brine.

2. The brine refining system of claim 1, wherein, The brine refining system further comprises an ammonia removal reaction tank (7), and the ceramic membrane filter (5) is communicated with the ammonia removal tower (8) through the ammonia removal reaction tank (7), wherein the ammonia removal reaction tank (7) is communicated with a sodium hypochlorite solution inflow pipe and a hydrochloric acid solution inflow pipe.

3. The brine refining system of claim 2, wherein, The ceramic membrane filter (5) is communicated with the coarse brine filter (4) through a brine feeding pipe, and is communicated with the ammonia removal reaction tank (7) through a filtered brine pipe.

4. The brine refining system of claim 3, wherein, The ceramic membrane filter (5) is further communicated with a re-filtering pipe, and is communicated with the brine feeding pipe through the re-filtering pipe.

5. The brine refining system of claim 4, wherein, The brine refining system further comprises a salt mud tank (6), and the ceramic membrane filter (5) is further communicated with a concentrated brine pipe, and is communicated with the salt mud tank (6) through the concentrated brine pipe.

6. The brine purification system of any one of claims 1-5, wherein, The brine refining system further comprises a heat exchange station (1), and the heat exchange station (1) is communicated with the precipitation reaction tank (3).

7. The brine purification system of any one of claims 1-5, wherein, The brine refining system further comprises a security filter (9), and the ammonia removal tower (8) is communicated with the security filter (9).

8. The brine purification system of any one of claims 1-5, wherein, A booster pump is arranged between the precipitation reaction tank (3) and the coarse brine filter (4).

9. The brine refining system of claim 6, wherein, A first regulating valve (2) is arranged on the communication pipe between the heat exchange station (1) and the precipitation reaction tank (3).

10. The brine refining system of claim 5, wherein, The filtered brine pipe is provided with three levels in parallel, one end of each level of the filtered brine pipe is communicated with the ceramic membrane filter (5), the other end of each level of the filtered brine pipe is communicated with the ammonia removal reaction tank (7), and a second regulating valve is arranged on each level of the filtered brine pipe.

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