Correlation between Growth Rate of Ice Crystals and Operating Condition in Direct Contact Freezing Process for Concentration of Sea Water

Abstract

In order to find the most suitable operating condition for concentration of sea water by means of the direct contact freezing process, a test plant that could be easily operated in a steady state was designed and built.The correlation between linear growth rate of ice crystals and operating condition of this plant was derived from the analysis of experimental data as follows:WI=3βIDIf (α/TDI)where, WI is crytalisation rate (or production rate), I is ice content in brine, T/α is holding time of ice crystals, DI is linear growth rate of ice crystals, and α, β are correction factors.DI was estimated by analysing the size distribution of ice crystals produced in the freezer during operation in its steady state.α was necessary because of the difference between the holding time of ice crystals and that of brine.β was necessary because the total surface area of the crystals varied with the change of the size distribution, even if the cumulative number of the crystals was constant.