A Novel Control Scheme Design and Implementation of Cane feeding System in Sugar Plant

Abstract

The cane feeding system of a sugar plant comprises cane preparatory devices, cane carrier and rake elevator. The cane preparatory devices are mounted above the conveyors. The cane is processed into small fibers, and fed to the milling process for juice extraction. In the selected plant, cane feeding process is either manually operated or maintained at constant speed. In some plants the automatic cane feeding is implemented. The conventional cane feed process is set point tracking control method. The existing method of feeding has various problems such as, uneven flow of cane results in frequent choking at mills, variations in boiler steam pressure and raw juice flow rate. This leads to the interruption in plant operation which affects the productivity. It is observed that the cane feeding is effectively influenced by variations in seven different parameters in the process line namely, kicker load, cutter load, mat level, fibrizer chest pressure, first mill chest pressure, Donnelly chute level and the raw juice tank level. A novel design of control scheme was formulated including the dynamic effects of all seven parameters for the cane feeding system. The designed control scheme was tested in hardware in the loop test setup in the lab. The retrofit implementation of the auto cane feeding system with new design was done in a sugar plant. The auto cane feeding system has shown improvements in the plant productivity, as the mill choking reduced, boiler steam pressure was normalized and the raw juice flow stabilization is achieved.