spiral chute 1.simple structure 2.lightweight, 3.no need power, saving water &electricity 4.easy to control ,high capacity spiral ... , sand, rill is better. The advantage is reasonable structure, simple fixed, less space, easily operated, concentrating even, separated clearly ... feeding size and chrome, granularity, grade, no noise.Features1.simple structure2.lightweight, 3.no need power, saving water & ...