EXPERIMENTAL STUDY ON NON-PLANAR SCREENING DEVICE FOR BUCKWHEAT THRESHING MATERIAL
Structural and motion parameters of screen surface have an important impact on the screening quality. In order to reduce the loss rate and impurity rate of buckwheat threshing material in the screening process and improve the screening performance of the vibrating screen, the planar square hole sieve, round hole sieve, non-planar convex-column sieve, pit sieve, and wave sieve were designed. Screening test was conducted on buckwheat threshing material under different screen structure based on the discrete element method (DEM). The results showed that the screening effect of convex-column sieve was the best, followed by pit sieve, and they were better than the traditional planar sieve. In single factor screening test of convex-column sieve, the ratio and height of convex column have significant influence on screening performance. Convex column rate, convex column height in a certain range were advantageous for screening. The results can lay a foundation for the determination of optimal parameter of screen structure and motion, and also provide a theoretical basis for the design of screening and cleaning equipment for buckwheat.
Abstract in Chinese