A study on the wear of sugar cane rolls

Abstract

Wear on sugar cane roll shells is costly maintenance problem for sugar cane mills. This research was conducted to understand the wear process in roll shells made of steel. In this process, sugarcane fiber – commonly called bagasse – is squeezed between grooved roll shells to extract sugar. A new test apparatus, based on the ASTM-G65 test machine, was built to study the wear caused by the slippage of bagasse on low-carbon steel under laboratory conditions. Contact pressure, mineral extraneous matter (MEM) within the bagasse, and velocity of the steel passing the bagasse were all varied. Silica sized in the range of 0.212–0.300 mm was used as the MEM. Wear on the specimens was gravimetrically measured. Surface roughness and micro-indentation hardness were measured before and after testing. New surfaces and worn surfaces were analyzed by using optical and scanning electron microscopy. The results showed that, in general, as contact pressure increases, there is higher wear. For high loads, a nearly linear relationship between wear and load was observed. Regarding MEM, a non-linear relation was found where wear increases swiftly for low silica content, but it is nearly constant for high silica content. No significant effect for velocity was found. At the end of wear testing, specimen surface looked smoother than the original machined surface; matching what was observed at the mill. The main wear mechanisms observed on the samples were ploughing and cutting by the silica. An empirical model based on a numerical regression of experimental volume loss was obtained.