Automatic handling of soft cane in the factory

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- and factory-scale experiments were conducted to evaluate the effects of potential strategies for processing soft canes, including changes in cane preparation and 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, 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 the 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 automated system with the manual alternative concluded that the automated soft-cane control system assisted in processing soft-cane varieties, although the relatively small amount of soft cane in the cane supply was not sufficient to provide definitive results.