GA Kent1, RC Parfitt2, K Ryan3, NJ McKenzie1 and F Plaza1
1Queensland University of Technology, Brisbane, Australia; g.kent@qut.edu.au
2Sugar Research Australia, Bundaberg, Australia
3Isis Central Sugar Mill Co. Ltd, Childers, Australia
This study was undertaken to address concerns that many cane varieties in the development pipeline in Australia have fibre quality classified as soft, with some soft enough to cause processing problems in the factory. Where soft canes have been approved for production, the factory has to have a strategy to process them. Small-scale and factory scale experiments were undertaken to understand the effects of potential strategies for processing soft canes, involving changes in cane preparation and in added-water rate. Once the effect of these potential strategies was measured, a control strategy was developed and implemented at Isis Mill in Australia. An experiment was completed to assess the benefits of the developed control strategy. From the small-scale shredder experiment, it was concluded that reducing shredder speed and increasing shredder grid setting reduced cane preparation but improved fibre quality. Soft canes generally achieved higher levels of preparation and so the shredder speed could be reduced, and the shredder grid setting could be increased when processing soft canes while still achieving acceptable preparation. From the factory experiments, it was concluded that changing shredder speed influences first-mill torque and changing added-water rate influences second to final mill torque. Following the installation of an automated shredder grid setting adjustor, shredder grid setting became a strategy for processing soft canes at #1 mill. The developed control strategy involved adjustments to shredder speed, shredder grid setting and added-water flow rate. An experiment comparing the results of the automated system to the manual alternative concluded that the operation of the automated soft-cane control system assisted in the processing of the soft-cane varieties although the relatively small amount of soft cane in the cane supply was not sufficient to provide definitive results.