Crystallization method with overflow of clear mother liquor

Abstract

The invention relates to a crystallization method with an overflow of a clear mother liquor, mainly solving the problems of small crystal size and frequent cleaning of the crystallizer existing in the prior art. The invention is characterized in that: raw material enters in a kettle-type crystallizer for crystallization; crystallized clear mother liquor in the kettle-type crystallizer flows out from the upper portion of the crystallizer; the crystal mush in the kettle-type crystallizer is divided into two parts- crystal mush I and crystal mush II, which flow out from the lower portion of the crystallizer; the crystal mush I is subject to separation through a solid-liquid separator to obtain crystals and crystallized filtrated mother liquor, the crystal mush II is subject to heat transfer through a jacketed crystallizer and returns to the kettle-type crystallizer, wherein, the weight ratio of the crystal mush I to the crystal mush II is 1:1-1:50; the crystals are discharged as products; the crystallized filtrated mother liquor is divided into two streams, the crystallized filtrated mother liquor I accounting for 5-95 wt% of the crystallized filtrated mother liquor is discharged, the crystallized filtrated mother liquor II accounting for 5-95 wt% of the crystallized filtrated mother liquor is mixed with the crystal mush II and then returns to the kettle-type crystallizer; raw material enters in the kettle-type crystallizer after mixing with the crystal mush II or directly enters in the kettle-type crystallizer, and the weight ratio of the crystallized mother liquor to the crystallized filtrated mother liquor I is 0.1:1-10:1. The invention can be applied in the industrial crystallization production.

Description

technical field [0001] The invention relates to a crystallization method with clear mother liquor overflowing. Background technique [0002] The kettle-type crystallizer is a type of crystallizer commonly used in industry. It uses the refrigerant in the jacket to exchange heat and cool the raw material, so that the product is crystallized from the raw material. The heat transfer efficiency of indirect heat exchange is low, and crystal scars are easy to form on the cooling surface, and the formed crystal scars will further reduce the heat transfer efficiency. Therefore, the production capacity of the kettle crystallizer is not high, and its production capacity is limited by the exchange rate of the crystallizer. thermal area. In order to further increase the production capacity of the kettle crystallizer, a casing crystallizer with a scraper is usually set outside the kettle crystallizer. The purpose of setting up the sleeve-type crystallizer is to provide more heat exchang...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is that the existing crystallization method has small crystal particle size and frequent cleaning of the crystallizer, and a novel crystallization method with clear mother liquor overflow is provided

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