Evaluation of a pilot-scale system for removing bagacillo from juice

Conventional use of rotary vacuum filters in the Australian sugar industry to remove pol from the clarifier mud has dictated that some bagacillo is allowed to flow through juice screens to mixed juice, to ensure an adequately porous mud cake is formed on the rotary vacuum filter screens. At some factories, particularly at times of high soil loading in the cane supply, additional bagacillo, such as supplied using a pneumatic separator, is added at the mud mingler. Bagacillo has detrimental effects on the juice processing stages such as increasing the mud volume in the clarifier, absorbing juice at many times its own mass, occasionally carrying over into the clear juice resulting in fugal screen blockages as well as reduced raw sugar quality. The quantity of mud cake transported back to the cane farms is also greatly increased due to the bagacillo loading in the mud cakes. Pilot-scale trials on the development of a modified process, where most bagacillo is removed from juice prior to the clarification stage and re-routed directly to the mud mingler in a more controlled and reliable manner, are described. Improved regulation of the fibre content in the feed to the mud filters would provide greater consistency and improved operation of the mud filters. Such a modified process also provides options for the use of alternative filter station technologies resulting in reduced pol loss, reduced mud cake return to the fields, and reduced supervision by operators.