A STUDY ON THE EFFECTS OF FINES DISSOLUTION ON THE STABILIZING CONTROL OF CONTINUOUS DTB CRYSTALLIZERS

摘要

The impact of incomplete dissolution of fines on the stabilizing control ofrncontinuous crystallizers is examined. In previous studies on the stabilizing controlrnof continuous crystallizers, it has usually been assumed that the fines completelyrndissolve within the fines dissolver. Nonetheless, this assumption is not always validrnfor industrial crystallization processes. In this study, the behavior of the stabilizingrncontrol system for a continuous crystallizer is simulated using a crystallizer modelrnthat accounts for the dissolution rate of crystals in the fines dissolver. It wasrnobserved that a conventional stabilizing controller may fail to stabilize the crystalrnsize distribution (CSD) when crystals do not completely dissolve in the dissolver.rnThis is due to a non-monotonic relationship between the fines flow rate and thernreduction in the total volume of crystals across the fines dissolver. This paper alsornhighlights the influence of the fines dissolver’s design on the stabilizing controller’srnperformance.