Influence of Sieve Structural Parameters on Sieving of Shelled Buckwheat

The problems of high falsesieving rate and low productivity are encountered while sieving shelled buckwheat with traditional round plate sieve. This paper presents a design idea for improving the sieving effect by changing the plate structure. The improved designs consist of a round plate sieve with larger percentage of sieving area than the traditional round plate sieve and a triangular plate sieve with the approximately same geometry as shelled buckwheat grains. Tests are conducted to compare the sieving performance of traditional round plate sieve with the newly designed round plate sieve with different percentage of sieving areas and apertures. Also the traditional round plate sieve is compared with triangle plate sieve with different percentage of sieving areas and apertures. Compared to traditional round plate sieve, the falsesieving rate for newly designed round plate sieve with an aperture isφ4.4mm is reduced by 3.6.A round plate sieve with a percentage of sieving area of59.7%, aperture ofφ4.3mm, is used to sieve the shelled buckwheat of sizeφ4.6~4.7mm.A falsesieving rate of2.3, and non-sieving rate of17.4 are obtained and the sieving effect is found to be the best. For the triangle plate sieve a falsesieving rate of90.2 and non-sieving rate of92.1 are obtained. The triangle plate sieve is found unsuitable for the sieving of shelled buckwheat.