A Feedback Control Method of Crystal Product Particle Size in the Process of Dissolution and Crystallization

Abstract

The invention relates to a feedback control method for crystal product granularity in the dilution crystallization process. The method includes the specific steps: estimating the sum of crystal granules according to expected average grain diameter of crystal products, comparing the sum of crystal granules N in crystallization mother liquor measured through an on-line granularity measurement apparatus in real time with the sum of crystal granules Ns specified in production, and synchronously controlling feeding rate of a crystal breaking system, dilution agent and solvent till the crystal products with expected granularity distribution are produced. Compared with the conventional granularity control method in the dilution crystallization process, the method has the advantages that the crystal products with expected granularity distribution can be produced automatically and conveniently as required by only regulating one parameter of the specified sum of crystal granules Ns without re-optimizing new process parameters and the grinding and screening process through plenty of experimental operation, and a granularity controllable regulation function of producing the crystal products with specified granularity distribution as required is realized.

Description

technical field [0001] The invention belongs to the technical field of industrial crystallization, and in particular relates to a feedback control method for the grain size of crystal products in the dissolution crystallization process. Background technique [0002] The dissolution and crystallization process is widely used in the fine chemical and pharmaceutical industries that have increasingly high requirements for product crystal quality, especially in the pharmaceutical and food industries where crystallized products are sensitive to temperature. Generally speaking, product crystals with large average particle size and monodisperse distribution are expected by the process industry, which can not only effectively improve the efficiency of downstream unit operations (such as centrifugation and drying processes after crystallization), but also improve the product process yield. It can also improve the efficacy of the product (such as bioavailability, drug stability). At p...

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Problems solved by technology

[0005] The present invention aims to overcome the technical defect of non-uniform particle size distribution of crystal products in the existing dissolution and crystallization process. The particle size distribution is concentrated, and the crystallization operation can be automatically regulated according to the specified average particle size of the crystal product to realize the controllable production of the average particle size of the crystal product

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