Finite Element Prediction of the Performance of Sugarcane Rolling Mills

Abstract

Extraction of juice from shredded sugarcane is commonly performed using sets of counter-rotating rolls. The design of sugarcane rolling mills is largely based on previous experience, and increases in crushing rate through factory mills have therefore been achieved by increasing blanket thickness rather than roll surface speed due to concerns regarding loss of extraction efficiency at higher rolling speeds. Estimation of roll loads, torques and expected juice extraction for a given mill design has likewise been empirical, with limited consideration of the underlying physical processes governing mill performance. The advent of finite element simulation techniques and increases in computing power have provided new tools to simulate and optimise rolling mill performance however. This study applies finite element methods to solve the governing mathematical equations for flow of juice through the fibrous sugarcane blanket and to predict roll load and torque, extraction energy, frictional sliding on the roll surface, and the behaviour of roll grooves during crushing. Our results to date suggest that higher roll speeds and thinner blankets (than those currently used in industry practice) would maintain crushing rates and juice extraction levels while reducing roll load, torque, and power consumption, and decreasing frictional sliding between rolls and cane blanket