Results of Theoretical Definition of Structural and Kinematic Parameters of Peeling Machine Working Elements

Abstract

Introduction. Peeling the moistened grains before grinding allows removing most of the outer shells with impurities on them from the grain surface. At the present time, the most commonly used machines for peeling are devices operating on the principle of “compression and friction”, in which the grains move along the friction surfaces of the working bodies. The aim of this study is to define and select structural and kinematic parameters of the machine working bodies, which would most effectively perform the process of peeling, and to make energy assessment of grain peeling. Materials and Methods. To identify the dependence of the machine design and operating parameters on the inclination angle and punching angle of the sieve cylinder, a diagram of the movement of the grain along the inclined cylinder was drawn up using elements of the theory of the motion of material point on rough surfaces. The motion of grains on the cylinder surface is analyzed by the methods of analytical dynamics. Results. The values of the geometric parameters of the particle position at point A are expressed as a function of the cylinder inclination angle α and the angle characterizing the shape of the inclined line of stamping of the cylinder β. Energy assessment of grain peeling process was made. With the radius of the sieve cylinder R0 = 0.135 m, the width of the working annular gap к = 0.01 m, the length of the cylinder L = 0.4 m, the horizontal arrangement of the cylinder, the angular velocity of the shaft ω = 90 rad/s, the angle of inclination of the stamping β = 22º, the calculated power was P = 4.5 kW. Discussion and Conclusion. As a result of analyzing the motion trajectory of the grain located on the cylinder surface, there have been proposed the formulas relating the shape of the inclined punching line of the cylinder, characterized by the angle β, to the inclination angle α, the radius R0 of the cylinder, the shaft angular velocity and the grain frictional properties. The obtained analytical dependencies can be used for the approximate definition of the peeling machine design and kinematic parameters.

Keywords

• grain surface cleaning
• peeling
• friction surface
• sieve cylinder
• process energy evaluation