Study of operation of four-screen shoes of grain-cleaning separators

Abstract

Screen shoes with three layout schemes of sieve arrangement were studied. There are separation and head screens installed in the upper tier in the first and third schemes, and in the lower one respectively there are two cleaning and two sorting screens, and in the latter between the tiers there is a rolling surface placed in the opposite direction of grain material movement. The second scheme involved the sequential installation of a sorting screen in the upper tier, and a cleaning and sorting screen in the lower tier. These schemes are used for preliminary, primary and secondary cleaning of grain material. The experimental studies made it possible to obtain the dependence graphs of the identified grain fractions on its supply to the beginning of the screen shoe, as well as the influence of grain supply on the quality indicators of winter wheat grain, such as the thousand-kernel weight of the main and forage fractions and the completeness of the fodder fraction extraction. The use of a screen shoe with a third layout scheme can provide seed cleaning with a supply of 0.38 kg/(s·m), commercial – with a supply of 1.05 kg/(s·m) and preliminary – with a supply of 3.94 kg/(s·m).