Abstract
The size control tests of crystals produced in industrial circulation-type crystallizers have been carried out, changing the salt production rate and the circulation flow volume, and some considerations based on a crystallization theory have been made on the test results. 1) The relation between the crystal size and the production rate. The crystal size has a tendency to increase with increase in the production rate in both flow types. In the case of reverse flow, there exists a clear relation because the growth rate for unit production rate is large. On the other hand, in the case of normal flow, the relation is not so clear because of small growth rate. 2) The relation between the crystal size and the circulation flow volume. With decrease in flow volume, the size increases effectivity in reverse flow, however, the reverse is found for normal flow, but with little change. The latter tendency is considered to be caused by the nucleation induced by bumping on liquid surface.
