Modeling of grain and seed shape to substantiate of seed cleaner sieve parameters

Seed cleaning is the mandatory technological operation of post-harvest processing of agricultural crops. During seed cleaning, trash, seed impurities and other components of the seed mass are separated from the grain/seeds of the main crop. The effective course of seed cleaning depends on the technological parameters of the seed mass and the parameters and mode of operation of the cleaner. Indicators characterizing the efficiency of the seed cleaner are productivity, indicator of seed separation, indicator of seed loss and indicator of seed damage. The technical indicators of the seed cleaner include the specific metal capacity and energy intensity of the seed cleaning process, as well as the degree of sieve surface utilization. The technological indicators of the seed mass are the moisture content and the ratio of mass components. The sieve is the working surface of the seed cleaner, which is characterized, among other things, by the shape and size of the holes and their position. In turn, the choice of the shape and size of the sieve holes depends on the shape and size of the components of the grain mass. It is important to determine the shape and size of the grains/seeds in order to justify the sieve parameters. This paper analyses known methods for the quantitative determination of grain/seed shape. The studies were carried out using a digital microscope and computer software for plotting and area determination of projection images and patterns of grains/seeds. The resulting mathematical models, which include the parametric equations of the ellipse and the modified super formula, describe the shape of the projections of linseed, wheat and maize, buckwheat and soya bean seeds. These mathematical models can be used in the design of sieve work surfaces of seed cleaner. A scheme and equation are also proposed for the determination of a complex indicator, which makes it possible to evaluate the design of any seed cleaner in comparison with other seed cleaners. A comprehensive indicator can be used to evaluate the design of any machines and equipment, as it takes into account all the parameters that affect the efficiency of their operation, and compare them with the best values of these parameters.