Grain Damage in Low­Speed Collision with the Surfaces of the Hoisting­and­Transport Machines Working Parts

Abstract

To reduce the damage level of wheat grains during its post-harvest processing, it is proposed to replace steel working parts in lifting and transporting machines with polymer ones. ( Research purpose ) Experimentally determine the dependence of the degree of wheat grain damage on the number of collisions, the incidence angle and the hoisting-and-transport machines working parts surface material when the grain moves at a speed of up to 3.5 meters per second. ( Materials and methods ) Experiments were carried out on a unit that reproduced the low-speed collision conditions of wheat grains with a smooth steel or plastic surface plate at various angles of incidence and the number of impacts. ( Results and discussion ) The authors identified a significant reduction in grain damage in a collision with a plastic plate compared to a steel plate – by 8-10 percentage points – is observed only at incidence angles of 60-90 degrees and the number of strokes from 5 to 10. It was found that at incidence angle up to 60 degrees, the specified difference didn’t exceed 4 percentage points and reached zero at an angle of 45 degrees. The low efficiency of replacing steel working parts with plastic ones to reduce grain damage when driving at low speed was explained by the weak manifestation of the decrease effect in the potential energy of grain deformation upon impact on a plastic surface at a collision low speed. ( Conclusions ) The authors determined that when grains moved at a speed of less than 3.5 meters per second in a rarefied stream without interaction between them, when individual grains collided with the hoisting-and-transport machines working parts, replacing steel working parts with plastic ones was impractical.