Automating the handling of soft canes through the factory

In recent years, concerns have been raised that many cane varieties in the development pipeline, particularly in the Central and Southern regions, have fibre quality classified as soft, with some soft enough to cause processing problems in the factory. The main issues have been feeding the cane through the milling train and high bagasse moisture content, causing subsequent combustion issues and low steam pressure at the boiler station. Experiments were carried out at Isis Central Mill to understand and improve the processing of existing soft cane varieties, including the characterisation of the physical properties of prepared cane using a pilot sized shredder (2019), factory milling train experiments (2020) adjusting shredder speed, added water temperature and added water rate, followed in 2021 by additions to the milling train control system to provide automated soft cane processing as well as the installation of an electro-mechanical shredder grid door actuator. This paper describes results obtained during the 2022 crushing season in which the automated control strategy to manage the processing of soft canes was introduced. The control strategy involved adjustments to three parameters: shredder speed, shredder grid door position, and maceration 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 processing the soft cane varieties, although the relatively small amount of soft cane in the cane supply was insufficient to provide definitive results.