Authors

Abstract

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

筛面结构参数和运动参数对筛分质量有重要影响。为了进一步降低荞麦混合脱出物在筛分过程的损失率、含杂率，提高振动筛的筛分性能，本文设计了平面方孔筛、圆孔筛，非平面凸柱筛、凹坑筛、波浪筛，并基于离散元法进行了荞麦混合脱出物不同筛面结构下的筛分试验。结果表明：在振动参数相同的情况下，非平面凸柱筛面的筛分效果最好，凹坑筛面次之，但均优于传统的平面圆孔筛和方孔筛。在凸柱筛面筛分试验中，凸柱率和凸柱高度对筛分性能影响显著。凸柱率、凸柱高度在一定范围内对筛分有利。所得结论可为最优筛面结构和运动参数组合的确定奠定基础，同时，亦能为荞麦混合脱出物的筛分、清选装置的设计提供理论依据。