Modified rotary-pinch chopper system for improved harvesting efficiency : SRDC Grower Group Innovation Project final report

Abstract

Bin weight is becoming an increasingly topical issue for the Australian sugar industry, with millers and haul-out contractors seeking to improve the efficiency of their operations by hauling more cane per trip using existing infrastructure. This has meant that there is considerable pressure within the industry to reduce billet length. This program of work aimed to facilitate the adoption of feedtrain/chopper synchronisation through the development of a modified rotary-pinch chopper system. The design principle is based on the concept of obtaining variable length billets through one revolution of the chopper drum, not through manipulating feedtrain roller speed. The conceptual design of the proof-of-concept modified rotary-pinch chopper system was developed and presented to Corradini Engineering for review, detailed design and manufacture. After fabrication the ‘Corradini’ proof-of-concept chopper system was installed on a harvester that is used to cut billets for planting and as a backup commercial machine. Initial comparative trials were successfully undertaken at Fairymead Plantation in Bundaberg during the 2006 harvest season. A standard 15-inch chopper system with unsynchronised (variable) and synchronised (uniform) feedtrain setup was compared with the ‘Corradini’ proofof- concept rotary-pinch chopper system (MRPCS) with synchronised feedtrain setup. The functionality of the ‘Corradini’ proof-of-concept MRPCS was assessed with no differences in operational performance observed or noted by the machine operator when compared with a standard 15-inch chopper system. This included no recirculation of billets and a throw velocity identical to that of a standard 15-inch system. In the 2006 trials, the ‘Standard’ chopper variable billet length treatment resulted in the greatest packing density, with 380 kg/m3 ,and the uniform length billets the lowest with 365 kg/m3. The packing density of the ‘Corradini’ proof-of-concept MRPCS variable length billet treatment was found to be 375 kg/m3 . The corresponding average reduction in bin weight from the standard chopper variable length billets was found to be 1%. Alternatively, an increase in bin weight of 2.7% was found when compared with the standard chopper uniform length billets.