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CN-224226711-U - Evaporation crystallizer for zero discharge recycling of coal chemical wastewater

CN224226711UCN 224226711 UCN224226711 UCN 224226711UCN-224226711-U

Abstract

The utility model relates to an evaporation crystallizer which is used for zero emission recycling of coal chemical wastewater and comprises a gasification separation chamber, a crystal growing chamber positioned below the gasification separation chamber, a circulating pipe, a circulating pump and a heat exchanger which are sequentially connected, wherein the bottom of the gasification separation chamber is provided with a central downcomer, the top of the crystal growing chamber is provided with a plurality of openings, the crystal growing chamber comprises an upper part and a lower part, the central downcomer at least extends to a crystal slurry area from the opening arranged at the top of the crystal growing chamber, the central downcomer consists of a main section and a diffusion section with a trapezoid longitudinal section, the included angle between the side wall of the diffusion section and the vertical direction is 10-30 degrees, the circulating pipe is connected with the other opening arranged at the top of the crystal growing chamber, and a discharge hole of the heat exchanger is connected with a feed hole of the gasification separation chamber. According to the utility model, through the optimization design of the included angle between the side wall of the diffusion section and the vertical direction, the energy loss can be reduced, the granularity of the product can be optimized, and the crystallization efficiency can be improved.

Inventors

  • HU ZHIPING
  • PAN WENGANG
  • BAI LIJUN
  • REN HUISONG
  • MA RUIJUN
  • SHAO MENGTING
  • FANG XIAOQIN
  • LU KUI
  • XIAO LONGBO

Assignees

  • 陕西煤业化工集团孙家岔龙华矿业有限公司
  • 上海晶宇环境工程股份有限公司

Dates

Publication Date
20260512
Application Date
20250429

Claims (10)

  1. 1. The evaporation crystallizer for zero emission recycling of the coal chemical wastewater is characterized by comprising a gasification separation chamber, a crystal growing chamber positioned below the gasification separation chamber, and a circulating pipe, a circulating pump and a heat exchanger which are sequentially connected; The gasification separation chamber is characterized in that a central downcomer is arranged at the bottom of the gasification separation chamber, a plurality of openings are arranged at the top of the crystal growth chamber, the crystal growth chamber comprises an upper part and a lower part, the upper part is divided into a fine crystal area and a first sedimentation area from top to bottom, the lower part is divided into a second sedimentation area, a crystal slurry area and a tumble area from top to bottom, the transverse sectional area of the upper part is larger than that of the lower part, the transverse sectional area of the second sedimentation area is larger than that of the crystal slurry area, the central downcomer extends to at least the crystal slurry area from the openings arranged at the top of the crystal growth chamber, the central downcomer consists of a main body section and a diffusion section with a trapezoid longitudinal section, and the included angle between the side wall of the diffusion section and the vertical direction is 10-30 degrees; The circulating pipe is connected with another opening arranged at the top of the crystal growing chamber, and the discharge port of the heat exchanger is connected with the feed port of the gasification separation chamber.
  2. 2. The evaporative crystallizer of claim 1, wherein the main section of the central downcomer has a diameter of 0.8-1.2m and the total length of the central downcomer is 4.0-5.0m, wherein the length of the diffuser section is 1.0-1.5 times the diameter of the central downcomer, and the main section extends from an opening centrally located in the top of the seeding chamber to the second settling zone.
  3. 3. The evaporative crystallizer of claim 1, wherein the bottom of the central downcomer is spaced from the bottom of the seeding chamber by a distance of 0.5-1.0 times the diameter of the central downcomer and/or the central downcomer extends from an opening centrally located at the top of the seeding chamber to the tumble zone.
  4. 4. The evaporative crystallizer as in claim 1, wherein the top of the evaporative separation chamber is provided with a steam outlet.
  5. 5. The evaporative crystallizer as in any one of claims 1-4, wherein the total volume of the seeding chamber is from 8.0 to 35.0 m 3 .
  6. 6. The evaporative crystallizer as in any one of claims 1-4, wherein the upper portion of the growth chamber is cylindrical with a transverse cross-sectional area of 6.00-8.00 m 2 , the second settling zone and the slurry zone in the growth chamber are inverted trapezoids in longitudinal cross-section, and the bottom area of the slurry zone is 2.00-3.00 m 2 .
  7. 7. The evaporative crystallizer of any of claims 1-4, wherein the fine grain region has a height of 30-50% of the total height of the seeding chamber, the first settling region has a height of 10-30% of the total height of the seeding chamber, the second settling region has a height of 10-20% of the total height of the seeding chamber, and the slurry region has a height of 10-20% of the total height of the seeding chamber.
  8. 8. An evaporative crystallizer as in any of claims 1-4 wherein the second settling zone and the side walls of the slurry zone are angled from 15 ° to 25 ° from vertical and/or the height of the tumble zone is 5-15% of the total height of the growth chamber and the tumble zone has an arcuate bottom surface with a transverse cross-sectional area less than the transverse cross-sectional area of the slurry zone.
  9. 9. The evaporative crystallizer as in any one of claims 1-4, wherein more than one outlet is provided on the bottom and/or side walls of the seeding chamber.
  10. 10. The evaporative crystallizer as in any one of claims 1-4, wherein the central downcomer is equipped with temperature sensors and/or pressure sensors.

Description

Evaporation crystallizer for zero discharge recycling of coal chemical wastewater Technical Field The utility model belongs to the technical field of wastewater treatment, and particularly relates to an evaporation crystallizer for zero-emission recycling of wastewater in coal chemical industry. Background Salt-containing wastewater containing a large amount of inorganic and organic impurities can be generated in industrial production such as coal mine and coal chemical industry. In the prior art, a crystallization system comprising an evaporation crystallizer is generally used for continuously concentrating salt-containing wastewater so as to realize zero discharge of wastewater, and the supersaturation degree of circulating mother liquor in the conventional evaporation crystallizer is not fully utilized to the crystal growth, so that the nucleation rate is higher than the crystal growth rate, a large number of new crystal nuclei are formed, and a large number of fine crystals are produced as a result, so that the obtained salt product has smaller granularity and cannot meet the use standard of products of downstream factories, and meanwhile, the bottom of the crystallizer is often subjected to salt deposition and needs to be cleaned regularly, thereby influencing the continuous production of the whole crystallization system. Disclosure of Invention Aiming at the defects in the prior art, the utility model aims to provide the evaporation crystallizer for zero discharge recycling of the wastewater in the coal chemical industry, which has the characteristics of high yield, optimized grain size and continuous production operation compared with the traditional crystallizer. Specifically, the evaporative crystallizer comprises a gasification separation chamber, a crystal growing chamber positioned below the gasification separation chamber, and a circulating pipe, a circulating pump and a heat exchanger which are connected in sequence; The top of the crystal growing chamber comprises an upper part and a lower part, the upper part is divided into a fine crystal area and a first sedimentation area from top to bottom, the lower part is divided into a second sedimentation area, a crystal slurry area and a tumbling area from top to bottom, the transverse sectional area of the upper part is larger than that of the lower part, the transverse sectional area of the second sedimentation area is larger than that of the crystal slurry area, the central downcomer extends to at least the crystal slurry area from the opening arranged at the top of the crystal growing chamber, and consists of a main body section and a diffusion section with a trapezoid longitudinal section, and the included angle between the side wall of the diffusion section and the vertical direction is 10-30 degrees; The circulating pipe is connected with another opening arranged at the top of the crystal growing chamber, and the discharge port of the heat exchanger is connected with the feed port of the gasification separation chamber. The structure of the evaporative crystallizer is shown in figure 1. In the utility model, the included angle between the side wall of the central downcomer diffusion section and the vertical direction is optimally designed, and the diameter of the diffusion section is gradually increased along the movement direction of the solution, so that the turbulent mixing effect of the crystal slurry can be effectively enhanced. Through the full contact between the solution and the crystal particles, the mass transfer efficiency is improved, meanwhile, the accumulation and agglomeration phenomena of crystals in the sedimentation process are avoided, and the uniformity and stability of crystal growth are ensured, so that the overall efficiency and the product quality of the evaporation and crystallization process are remarkably improved. The central downcomer can be made of stainless steel or titanium alloy, and the like, and can be coated with a coating on the surface so as to resist corrosion and high temperature, and can be selected according to different chemical environments in practice. Preferably, the central downcomer has a diameter of 0.8-1.2m and an overall length of 4.0-5.0m, wherein the diffuser section has a length of 1.0-1.5 times the diameter of the central downcomer, and the main section extends from an opening centrally located in the top of the growth chamber to the second settling zone, preferably the middle of the second settling zone. The diameter and the length are designed according to the process requirements of the scale, the treatment capacity and the like of the evaporation crystallizer. Preferably, the distance between the bottom of the central downcomer and the bottom of the seeding chamber is 0.5-1.0 times the diameter of the central downcomer. Preferably, the central downcomer extends from an opening centrally located at the top of the seeding chamber to the tumble zone. Below the bottom of the central down