Low-pressure sugar extraction with screw-press conveyors - Texas A&M University (TAMU) Scholar

Traditionally, screw presses have been used sporadically in place of roller mills for high-pressure extraction. Under these highly abrasive conditions, screw presses do not handle well; therefore, they have not gained much popularity. If a gentle squeeze is applied instead, the inherent problems may be overcome. Screw presses have several advantages over mills (e.g., lower capital and maintenance costs, dewatering to a fixed moisture content regardless of moisture content at the inlet), which merits further study of such system. A countercurrent diffusion process aided at each stage by a gentle squeeze provided by screw presses has been proposed. The presses, as they dewater material, also convey it to the next stage; therefore, they have been dubbed "screw-press conveyors." A high liquid content before each press may allow mixing to be implemented to attain equilibrium at each stage. The performance of a pilot-scale screw-press conveyor was tested. The unoptimized equipment decreased liquid content from 96 to 89%. Simulation of the process suggested that, with final dewatering to 45% moisture, eight stages are necessary to achieve 98% recovery from typical sugarcane. The cumulative power for a system of eight of these low-capacity unoptimized screw-press conveyors is 14.0 1.7 kWh/dry tonne of fiber.

Low-pressure sugar extraction with screw-press conveyors Academic Article