Size of Product Crystals of Sodium Chloride

Abstract

Correlation between the size of product crystals of sodium chloride and the productivity of a continuous crystallizer was tested in our plant.
We used a forced circulation evaporator with a vertical external heating element as a continuous crystallizer. Feed solution used was saturated brine obtained by an ion exchange membrane electro dialyzer.
Crystal sizes were tested based on production rates being controlled by the volume of heating steam, which varied from 2 to 8t/h, and circulating speed of solvent solution at the rate of 40m³/min (regulated by 50Hz of the circulating pump). The density of crystals in solution was preservedat 10%.
The shape of the surface of products was observed by electron microscope.
As the result, we could not find out “the first operational line” because the the circulating volume of crystals in the evaporator was supposedly too little.