Numerical simulation of heat, mass and momentum transfer during NH4H2PO4 crystal growth by solution circulating method

Abstract

Three-dimensional unsteady numerical simulations are carried out to study the interactions of heat, species transport and fluid flow during the ADP crystal growth by solution circulating method (SCM). The supersaturation distribution on the crystal surface under different conditions is investigated and the effects of temperature and flow fields on the surface supersaturation are analyzed in detail. The results show that the magnitude and distribution of the surface supersaturation are improved when the rotation rate gets high. With an increase of the inlet velocity, there is a reduction in the magnitude of the surface supersaturation, while the uniformity of the supersaturation distribution is improved slightly. Besides, the increase of the inlet temperature decreases the magnitude of the surface supersaturation. As the crystal size gets large from 50 to 70 mm, the magnitude of the supersaturation on the crystal surfaces reduces obviously, but a little improvement can be seen in the uniformity of the supersaturation distribution on the prismatic faces.