The trajectory of the grains on the circular sieve

Modern production requires new and more efficient machines for cleaning grain heap. Of the industry of grain-cleaning machines the greatest component is based on reciprocating motion of the sieve mill. When working with such machines the performance is much less in comparison with machines in which the sieve mill performs a circular motion. However, no clear picture of the trajectory of grain heap on the sieve. To assess the quality of the sieve mill performs a circular movement developed a mathematical model for the motion of grains on the sieve. The trajectory is a cycloid. Depending on the frequency of rotation of the sieve of the cycloid can be shortened or extended, in our case, when the given parameters of the rotation frequency of ω = 80-140 min-1 at the beginning of the motion of grains on the sieve, first performs a circular movement, turning into an elongated cycloid with a consequent increase in the distance between the loops. On the basis of the calculations it can be concluded that at low speeds the residence time of grain heap on the sieve is reduced, and when the maximum frequency increases due to the small distance between the loops of the cycloid, which increases the probability of a weevil in a cell sieve. During circular motion, the orientation of the grains relative to the holes of the sieve changes several times faster than the reciprocating motion. And the change of the angle of inclination of the holes relative to the longitudinal axis of the sieve allows to increase the capacity and improve the quality of separation of the grain material.