| Abstract: | Solventing_out crystallization is widely used in the process of industrial organic crystallization. However, some problems also extensively exist in it.For example, the crystal dominant size is small and coefficient of variation is high, the products are difficult to separate from crystal syrup and the impurity content of products is high. In view of the above problems, this paper studied meta_stable zone quality of solventing_out system by using the following enhancing methods: using pressure dissolving and still cooling to increase supersaturation, adding surfactant to precipitant and using blade friction and ultrasound stimulation to increase nucleation rate, keeping crystals with dynamic state alternating with still state to decrease growth dispersion, adding substance which can promote the change of crystal configuration to obtain the ideal configuration crystals, and feeding precipitant according to the optimum operation procedure to maintain constant crystallization supersaturation. The experiments show that these methods improve the product quality significantly. |
