Evaluation of an alternative vacuum pan control scheme

Abstract

Conductivity-based vacuum pan controllers dominate the Australian sugar industry. A new scheme, based on Brix control of the massecuite and mother molasses is proposed. Multi-loop control of the process is demonstrated, whereby the massecuite Brix is controlled by manipulating the liquor/A molasses feed rate to the pan and the mother molasses Brix is controlled by manipulating the steam flow rate to the pan. A single loop controller is also proposed, which controls massecuite Brix by manipulating the feed flow to the pan. The steam flow rate is set manually (i.e. mother molasses Brix is uncontrolled). A gPROMS simulation of a pivot pan under typical operating conditions demonstrates the efficacy of this approach.