Inertial method of cleaning plate sieves of grain cleaning machines from stuck impurities

Abstract

In a grain cleaning machine with a sieve block consisting of flat punched sieves, setting the sieves for cleaning a specific crop is done by replacing the sieves which often requires considerable time. Therefore, the use of plate sieves in grain cleaning machines is of interest. One of the problems of using plate sieves in grain cleaning machines is cleaning sieves from stuck impurities. Known devices such as brush or ball cleaners are not suitable for this type of screen. The research target is the cleaning of stuck impurities from a plate sieve. The separating surface of a proposed sieve is made in the form of plates containing bumper pins and axles installed in the grooves of the sidewalls of the sieve. The gap between the plates is adjusted by moving the adjustment rail. The condition for releasing a particle stuck in the working gap is determined taking into account known mathematical models that describe the behavior of a particle on a sieve plate. A coefficient has been introduced showing the ratio of the releasing force to the weight of the particle and assessing the self-cleaning ability of the plate sieve. It has been revealed that the self-cleaning ability of a plate sieve mainly depends on the kinematic mode of the sieve, and the angle of inclination of the plate has a slight effect. The force holding the particle in the working gap may be reduced by briefly increasing the gap between the plates at the end of the oscillation period by installing a movement limiter for the adjustment rail. The dependencies that determine the design parameters of the device that implements the proposed method of cleaning plate gratings are determined.