Laminar flow continuous settling crystalliser. Part 2. Modifications

Abstract

This paper (Part 2 of 2) revises and expands on the original model for the laminar flow continuous settling crystalliser presented in Part 1 in an effort to understand why the original model over-predicted product particle d10 and d50 and under-predicted the span and d90. Because agglomerates were observed experimentally, an agglomeration term was added to the initial theoretical model resulting in no significant particle size distribution prediction changes. On further analysing potential flow conditions a region of high flow and a subsequent area of low flow explained the d50 and span deviations found experimentally. It was concluded that the difference between the ideal predicted spans and the experimental spans was due to non-ideal laminar flow conditions existing in the column. Although not achieved experimentally, it is postulated that an ideal parabolic laminar column flow profile would result in a narrow particle size distribution.