Evaluation of the Neltec ColourQ 1700CC for measuring the purity of magma from C centrifugals

In Australian sugar factories one operator typically manages the high-grade fugalling, sugar- drying and low-grade (C) fugalling stations. The C fugals are managed least effectively as there is no process instrumentation to monitor on-line C sugar purity or final molasses purity. Conditions can change rapidly in the C fugals without the operator being aware, and poor performance can persist for several hours. Tight control of the C sugar purity is important to avoid high sucrose losses to final molasses or an excessive recycle of impurities in the C sugar (magma or remelt) to the pan stage. For the 2017 season, Isis Mill purchased a Neltec ColourQ 1700CC transducer that had been recently released on the market to measure the colour (inferred purity) of the total C sugar magma production of the station. The transducer proved effective for the operators to pragmatically achieve tighter control of the purity of the C sugar magma. For the 2018 season, Isis Mill purchased a second ColourQ 1700CC transducer to monitor the colour of the C sugar on the screen within their large capacity fugal. Described are the results of extensive testing of the transducer mounted on the fugal and the use of the transducer to assist operators achieve tighter control of the magma purity. The experiences with the use of the transducer on the magma screw for monitoring the purity of the total C magma production from the station are also described. Key words Continuous centrifugals, magma purity, colour, control