System for improving salt purity of salt separation system

Abstract

The utility model discloses a system for improving salt purity of a salt separation system, which belongs to the technical field of salt purification and comprises a thickener, a centrifugal machine, a clarifier and a clear liquid tank, a first stirrer is arranged in the thickener, a first stirring blade is arranged at one end of the first stirrer, and a second stirring blade is arranged at the other end of the second stirrer. The system for improving the salt purity through the salt separation system has the beneficial effects that the clarifier is arranged, so that overflowing mother liquor can be efficiently clarified, the centrifugal machine is arranged, crystal separation can be realized, and the central circulating pipe is arranged, so that the effects of impact prevention and buffering can be achieved; by arranging the first stirrer, the second stirrer, the first stirring blade and the second stirring blade, crystal growth can be efficiently promoted, meanwhile, the purpose of preventing deposition can be achieved, by arranging the fine grain eliminator, hot water can be supplemented to eliminate fine grains, and by arranging the overflow weir, the purpose of separating overflow clear liquid can be achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of salt purification, and more specifically, to a system for improving the purity of salt in a salt separation system. Background Art

[0002] The salt content of most industrial wastewaters is relatively complex, and the solid mixed salts obtained by evaporation are basically treated as solid hazardous wastes or even dangerous wastes. At present, the treatment cost of solid waste and hazardous waste in China is expensive. Therefore, salt separation and crystallization has great application value, which can reduce the generation of waste salt and create by-product value at the same time. In the field of evaporation crystallization and salt separation, according to the different solubilities of each solute in the solution at corresponding temperatures, the phase diagram theory is used to control appropriate operating temperatures and concentration multiples during the crystallization process for salt separation.

[0003] During the production stage, it is still very difficult to achieve a high level of salt purity in the salt produced by evaporation crystallization, excluding water quality fluctuations or differences in personnel operations. Our company found through on-site sampling and testing that the salt leakage rate of the solid-liquid separation equipment is the key to the problem. That is to say, after evaporation and concentration, solid salt A is precipitated. However, due to the processing accuracy limitations of the metal screen of the centrifuge, there is a certain salt leakage rate, and the process of separating solid salt A is not thorough, resulting in the mother liquor still carrying a small amount of solid salt A into the next section. In this way, it is very difficult to achieve high purity of solid salt B. In our company's engineering projects, the multi-stage clarification method can control the salt leakage rate within 0.1%, effectively improving the salt quality and having a higher by-product value. Content of the Utility Model

[0004] (1) Technical Problems to be Solved

[0005] Aiming at the deficiencies of the existing technology, the purpose of the utility model is to provide a system for improving the purity of salt in a salt separation system, which has the characteristics of higher salt quality, simple structure, higher salt recovery rate and improved crystal particle uniformity.

[0006] (2) Technical Solutions

[0007] To achieve the above object, the present utility model provides a system for improving salt purity in a salt separation system, which includes a thickener, a centrifuge, a clarifier and a clear liquid tank. A first stirrer is arranged inside the thickener, and a first stirring paddle is arranged at one end of the first stirrer. A thick slurry discharge pipe is arranged between the thickener and the centrifuge. The clarifier is successively an overflow section, a clarification section and a crystal growth section from top to bottom. A central circulation pipe is arranged between the clarification section and the crystal growth section. A second stirrer is arranged at the bottom of the crystal growth section, and a second stirring paddle is arranged at one end of the second stirrer. A fine crystal eliminator is arranged between the clarification section and the crystal growth section. An overflow mother liquid pipe is arranged between the central circulation pipe and the thickener. An overflow weir is arranged inside the overflow section. A reflux pump is arranged between the crystal growth section and the thickener. A clear liquid overflow pipe is arranged between the overflow section and the clear liquid tank.

[0008] When using the system for improving salt purity in a salt separation system of this technical solution, by arranging the clarifier, it can efficiently clarify the overflow mother liquid. By arranging the centrifuge, crystal separation can be achieved. By arranging the central circulation pipe, the effects of shock prevention and buffering can be achieved. By arranging the first stirrer, the second stirrer, the first stirring paddle and the second stirring paddle, crystal growth can be efficiently promoted, and at the same time, the purpose of preventing deposition can be achieved. By arranging the fine crystal eliminator, hot water can be supplemented to eliminate fine crystals. By arranging the overflow weir, the purpose of separating overflow clear liquid can be achieved.

[0009] Further, a crystal slurry feed pipe is arranged at the top of the thickener.

[0010] Further, a mother liquid outlet is arranged on one side of the centrifuge.

[0011] Further, a solid salt outlet is arranged on the other side of the centrifuge.

[0012] Further, a clear liquid external discharge pump is arranged at the bottom of the clear liquid tank.

[0013] Further, the thick slurry discharge pipe, the mother liquid outlet, the crystal slurry feed pipe and the overflow clear liquid pipe are all finished seamless steel pipes.

[0014] (III) Beneficial effects

[0015] In summary, the present utility model has the following beneficial effects:

[0016] 1. By arranging the clarifier, it can efficiently clarify the overflow mother liquid. By arranging the centrifuge, crystal separation can be achieved. By arranging the central circulation pipe, the effects of shock prevention and buffering can be achieved;

[0017] 2. By setting the first stirrer, the second stirrer, the first stirring blade and the second stirring blade, the crystal growth can be efficiently promoted, and at the same time, the purpose of preventing deposition can be achieved. By setting the fine crystal eliminator, hot water can be supplemented to eliminate fine crystals. By setting the overflow weir, the purpose of overflow clear liquid separation can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for describing the specific embodiments or the prior art. Obviously, the drawings in the following description are only one embodiment of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a schematic diagram of the system flow of the present invention.

[0020] The reference numerals in the drawings are:

[0021] 1. Crystal slurry feed pipe; 2. First stirrer; 3. Thickener; 4. First stirring blade; 5. Thick slurry discharge pipe; 6. Centrifuge; 7. Mother liquor outlet; 8. Solid salt outlet; 9. Overflow mother liquor pipe; 10. Overflow section; 11. Overflow weir; 12. Clarifier; 13. Clarification section; 14. Central circulation pipe; 15. Fine crystal eliminator; 16. Second stirring blade; 17. Crystal cultivation section; 18. Return pump; 19. Second stirrer; 20. Clear liquid overflow pipe; 21. Clear liquid tank; 22. Clear liquid external discharge pump. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the technical solutions in the specific embodiments of the present invention will be clearly and completely described below to further illustrate the present invention. Obviously, the specific embodiments described are only a part of the embodiments of the present invention, rather than all the styles.

[0023] Example:

[0024] The following will further elaborate on the present invention in conjunction with the attached Figure 1 drawings.

[0025] Please refer to Figure 1, the present utility model provides a technical solution: a system for improving salt purity in a salt separation system, including a thickener 3, a centrifuge 6, a clarifier 12 and a clear liquid tank 21. By setting the clarifier 12, it can efficiently clarify the overflowing mother liquor. By setting the centrifuge 6, crystal separation can be achieved. A first stirrer 2 is arranged inside the thickener 3, and a first stirring blade 4 is arranged at one end of the first stirrer 2. A thick slurry discharge pipe 5 is arranged between the thickener 3 and the centrifuge 6. The clarifier 12 is successively an overflow section 10, a clarification section 13 and a crystal growth section 17 from top to bottom. A central circulation pipe 14 is arranged between the clarification section 13 and the crystal growth section 17. By setting the central circulation pipe 14, it can play the role of anti-impact and buffering. A second stirrer 19 is arranged at the bottom of the crystal growth section 17, and a second stirring blade 16 is arranged at one end of the second stirrer 19. By setting the first stirrer 2, the second stirrer 19, the first stirring blade 4 and the second stirring blade 16, it can efficiently promote crystal growth and at the same time play the role of anti-deposition. A fine crystal eliminator 15 is arranged between the clarification section 13 and the crystal growth section 17. By setting the fine crystal eliminator 15, hot water can be supplemented to eliminate fine crystals. An overflow mother liquor pipe 9 is arranged between the central circulation pipe 14 and the thickener 3. An overflow weir 11 is arranged inside the overflow section 10. By setting the overflow weir 11, the purpose of separating overflow clear liquid can be achieved. A reflux pump 18 is arranged between the crystal growth section 17 and the thickener 3, and a clear liquid overflow pipe 20 is arranged between the overflow section 10 and the clear liquid tank 21.

[0026] Specifically, a crystal slurry feed pipe 1 is arranged at the top of the thickener 3, and a mother liquor outlet 7 is arranged on one side of the centrifuge 6.

[0027] By adopting the above technical solution, by setting the crystal slurry feed pipe 1, it is convenient to feed the crystal slurry, and by setting the mother liquor outlet 7, it is convenient to discharge the mother liquor.

[0028] Specifically, a solid salt outlet 8 is arranged on the other side of the centrifuge 6, and a clear liquid discharge pump 22 is arranged at the bottom of the clear liquid tank 21. The thick slurry discharge pipe 5, the mother liquor outlet 7, the crystal slurry feed pipe 1 and the overflow clear liquid pipe are all finished seamless steel pipes.

[0029] By adopting the above technical solution, by setting the solid salt outlet 8, the solid salt can be discharged, and by setting the clear liquid discharge pump 22, the clear liquid can be discharged.

[0030] The working principle of the present utility model is:

[0031] First, the crystal slurry in the evaporator is transported to the middle and lower part of the thickener 3 through the crystal slurry feed pipe 1 by the front-end feed pump. Driven by the first stirrer 2 and the first stirring blades 4, the crystal slurry is maintained at a low-speed agitation, and the rotation speed is controlled at 20 - 40 r / min. The physical thickening effect of the crystal slurry is achieved in the thickener 3, that is, the solid salt with a large density sinks to the bottom of the cone of the thickener 3 by its own gravity for collection, and leaves the thickener 3 along the thick slurry discharge pipe 5 from the bottom discharge port of the cone, and enters the solid-liquid separation equipment centrifuge 6 for centrifugal separation. The separated solids are taken out through the solid salt outlet 8 and connected to the next-level ton bag or conveyor belt. The separated mother liquor is connected to the centrifugal mother liquor tank through the centrifugal mother liquor outlet 7 and then transported back to the evaporation system for continuous evaporation; while the mother liquor with a small specific gravity floats to the upper clarification section 13 of the thickener 3 and enters the next-level clarifier 12 along the overflow mother liquor pipe 9. Due to the limitations of the stirring speed in the thickener 3 and the floating speed of the clear liquid, a small amount of fine crystals inevitably need to be entrained in the floating mother liquor. The mother liquor with a small amount of fine crystals enters the crystal cultivation section 17 at the bottom of the clarifier 12 through the central circulation pipe 14 to participate in the circulating crystal cultivation. The feeding central circulation pipe 14 reduces the feeding impact. Driven by the second stirrer 19 and the second stirring blades 16, the mother liquor with crystals is maintained at a slow agitation, and the rotation speed is controlled at 5 - 15 r / min. The crystals collide with each other under the slow agitation, and the residence time is 4 - 8 h to achieve the growth of crystal particles. The extremely fine crystals are redissolved by the fine crystal eliminator 15. The large-particle crystals at the bottom of the clarifier 12 where crystal growth is achieved are transported back to the thickener 3 by the reflux pump 18 to continue to participate in the thickening process and the centrifugal separation process. The upper liquid of the clarifier 12 is subjected to gravity clarification separation through the clarification section 13, and the clear liquid overflows through the overflow weir 11 of the overflow section 10. The amount of carried crystals is extremely small, and it overflows to the clear liquid tank 21 through the clear liquid overflow pipe 20 and is transported to the section for extracting solid salt B by the clear liquid external discharge pump 22.

[0032] This specific embodiment is only an explanation of the present invention, and it is not a limitation of the present invention. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions according to needs, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law.

Claims

1. A system for improving the purity of salt in a salt separation system, comprising a thickener (3), a centrifuge (6), a clarifier (12) and a clear liquid tank (21), characterized in that: The thickener (3) is provided with a first agitator (2) inside, and a first agitator blade (4) is provided at one end of the first agitator (2); a thick slurry discharge pipe (5) is provided between the thickener (3) and the centrifuge (6); the clarifier (12) comprises an overflow section (10), a clarification section (13) and a crystal growing section (17) from top to bottom, a central circulation pipe (14) is provided between the clarification section (13) and the crystal growing section (17); a second agitator (19) is provided at the bottom of the crystal growing section (17), and a second agitator blade (16) is provided at one end of the second agitator (19); A fine crystal eliminator (15) is provided between the clarification section (13) and the crystal growing section (17), an overflow mother liquor pipe (9) is provided between the central circulation pipe (14) and the thickener (3), an overflow weir (11) is provided inside the overflow section (10), a reflux pump (18) is provided between the crystal growing section (17) and the thickener (3), and a clear liquid overflow pipe (20) is provided between the overflow section (10) and the clear liquid tank (21).

2. A system for improving salt purity in a salt separation system according to claim 1, characterized in that: A slurry feed pipe (1) is provided at the top of the thickener (3).

3. A system for improving salt purity in a salt separation system according to claim 1, characterized in that: A mother liquor outlet (7) is provided on one side of the centrifuge (6).

4. A system for improving salt purity in a salt separation system according to claim 1, characterized in that: A solid salt outlet (8) is provided on the other side of the centrifuge (6).

5. A system for improving salt purity in a salt separation system according to claim 1, characterized in that: A clear liquid discharge pump (22) is provided at the bottom of the clear liquid tank (21).

6. A system for improving salt purity in a salt separation system according to claim 1, characterized in that: The concentrated slurry discharge pipe (5), the mother liquor outlet (7), the slurry feed pipe (1) and the overflow clear liquid pipe are all finished seamless steel pipes.

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