STUDY OF THE INFLUENCE OF TRIBOLOGICAL AND ELECTRICAL PROPERTIES OF WINTER RAPE SEEDS ON THEIR EQUILIBRIUM ANGLE ON THE SEPARATING PLANE
Keywords:Rapeseed, tribological properties, electrical properties, equilibrium angle, electric separator.
In many cases, it is possible to obtain the high-quality seed material of difficult-to-separate seed mixtures of agricultural crops in the process of its post-harvest processing on electric separators, in which the working body is an inclined plane moving in an electric field. On such a plane, separation is carried out according to the set of tribological, physical-mechanical and electrical properties of the constituent components. The efficiency of electroseparation can be increased by thorough investigation of these properties both for crop seeds and for weed seeds or various types of injured grains.
It is found out that the universal criterion, on the basis of which it is possible to analyse the influence of tribological, physical-mechanical and electrical properties on the behaviour of the components of a difficult-to-separate seed mixture on the separating plane, is the angle of equilibrium of the seed on it.
The mathematical expression of the equilibrium angle is formulated, in which the shape, dimensions, roughness, material of the separating plane are represented by the friction angle j, and the electrical properties of the seeds (electrical conductivity, dielectric permittivity, etc.) – by the multiplicity of the electric force kо.
Due to the experimental studies of the equilibrium angles of winter rape seeds, as well as various types of injured seeds, it has been found out that shrunken, injured seeds, compared to high-quality ones, have larger values of the equilibrium angles, and this confirms the possibility of their separation on the inclined separating plane moving in the electric field.
Under the condition of choosing the optimal value of the speed Vn and the intensity of the electric field E, it is possible to achieve the maximum difference in the values of the Δαр equilibrium angles for individual seeds, and at the same time to achieve an effective mode of operation of the separator. The equilibrium angle αр of the components of the seed mixture has a decisive influence on the design parameters (dimensions) of the working body (plane) of the electric separator.