ONLINE CLEANING OF A VERTICAL CONTINUOUS VACUUM PAN

THIS PAPER ADDRESSES the theory and recommended control logic for an online cleaning procedure of a vertical continuous vacuum pan. The online cleaning procedure increases the massecuite temperature in the pan by increasing the head space pressure, which results in the release of sugar build-up and re-establishes pan circulation. An International Society of Sugar Cane Technologists (ISSCT) Process Workshop held in South Africa in 2014 reported the use of an online cleaning program for continuous vacuum pans in South African mills. Wilmar Sugar conducted trials of this procedure during the 2015 crushing season on a vertical continuous high grade seed pan at Victoria Mill. The main objective of the project was to increase the period between continuous pan water boils that were regularly required to remove sugar crystal build-up inside the pan. The outcome from the project showed an improvement in this period from 7 to 14 days for the continuous high grade seed pan. No adverse impacts were noted and an improvement in product sugar quality was evident. The major benefit from the implementation of this cleaning procedure was the reduction in the number of pan water boils that had to be undertaken during the season.