Optimization Of Crystallizer With Draft Tube

Usually in the operation of industrial crystallization, there are several phenomenons which could affect crystallization. Due to continuous reaction, and the secondary crystallization of crystal, crystal will appear the phenomenon of the hanging wall. If the mixture is not sufficient in stirred tank, crystal will sink by its own gravity, finally it causes the crystal accumulated in the bottom of the reactor, and easily to jam the discharge in the continuous devices. Most of the crystallization operation need to get uniform crystal particles, and want the larger particle size. According to the above problems, this article want to improve the structure of the draft tube in the stirring crystallizer, to improve the situation and find the optimal crystallization reactor which can get the best crystal.This paper use the CFD simulation software to analysis the flow field in the vessel, shear rate distribution, the velocity in the bottom of the vessel and the surface of the vessel in6crystallizers, which contains the vessel without draft tube, the vessel with straight draft tube, and the vessel with designed draft tube, in order to observe the factors in the vessel during the crystallization process. The paper designed the vessel with segmented draft tube and an impeller with an affiliated blade (D/T=0.98) for the first time. Compared with the crystal particle sizes, the suspension speed from the bottom, the power number and the power in the vessel with draft tube, without draft tube and the vessel with segmented draft tube. And this paper gives the suitable stirred crystallizer in different conditions according to the results of experiments and simulations.