A method for returning small crystal particles in the slurry discharged from a reaction crystallizer

Abstract

The invention discloses a method for returning small crystal particles in the slurry discharged from a reaction crystallizer. The method includes the following steps: (1) The slurry discharged from the reaction crystallizer first enters a slurry storage tank, and then is sucked out by a venturi tube and fed from The clear liquid of the clear liquid circulation pump is mixed and diluted; (2) The diluted slurry enters the hydrocyclone for continuous separation of large and small crystal particles, and the large particles and a small part of the clear liquid are taken out as underflow and enter the product storage tank, and the small particles and Most of the clear liquid is discharged into the settling reflux tank as the top flow; (3) In the settling reflux tank, small crystal particles settle down and return to the reaction crystallizer to continue to grow; (4) Most of the supernatant in the settling reflux tank The liquid is pumped out by the clear liquid circulating pump as carrier fluid and diluent, and a small part goes to the water treatment unit. The method has low equipment investment, is easy to realize continuous operation, can effectively improve the particle size distribution of the product, and can simultaneously improve the utilization efficiency of the raw material liquid and avoid environmental pollution.

Description

technical field [0001] The invention relates to the field of reaction crystallizers, in particular to a technical proposal for returning small crystal particles in slurry discharged from a reaction crystallizer. Background technique [0002] For the continuous or semi-continuous operation of the reaction crystallizer, the output slurry often contains mature large crystal particles and immature small crystal particles at the same time. The presence of these small crystal particles will affect the particle size distribution of the product and reduce the quality of the product. If these immature small crystal particles can be separated from the slurry, the particle size distribution of the product can be effectively improved and the quality of the product can be improved. Furthermore, if these separated small crystal particles can be returned to the reaction crystallizer to continue to grow into mature large crystal particles, the utilization efficiency of the raw material liq...

AI Technical Summary

Problems solved by technology

However, this method has the following disadvantages: (1) The separation of large and small crystal particles is carried out after filtration, washing and drying, which greatly increases the load and cost of the previous operation, because the final small crystal particles must be added with water to form a slurry (2) Liquid-solid separation is not easy to achieve continuous operation by means of filtration; (3) Mechanical transportation equipment will be used in the process of slurry transportation, which may break large crystal particles and increase the concentration of fine powder. content

[0004] Therefore, so far, there is still no energy-saving, environmentally friendly, and efficient method that can separate the small crystal particles in the slurry discharged from the reaction crystallizer and return them to the reaction crystallizer to continue growing.

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