ТЕОРЕТИЧЕСКИЕ ИССЛЕДОВАНИЯ ТЕХНОЛОГИЧЕСКОГО ПРОЦЕССА РАБОТЫ СЕПАРАТОРОВ ДЛЯ ОПРЕДЕЛЕНИЯ ПОТЕРЬ ЗЕРНА

Abstract

Determining the level of permissible grain loss during the operation of combine harvesters is associated with the difficultyof taking a sample from under the working combine harvester according to all the GOST requirements and its further processing. To determinegrain losses, the authors carried out theoretical studies of the technological operation of separators and considered the theory of separatingthe mixture components by specific gravity. The results of previous studies, as well as some information from the relevant research reportswere used. Three factors influencing the calculation accuracy were taken into account: the nature of forces acting on individual particlesin the separator layer; the aerostatic field exerting an aerostatic influence on the individual particles, which ensures their separationat operating speeds of the separator air flow; the mixing of particles in the sample layer and their separation by specific gravity. It was determined that when the air flow passes through a layer of bulk sample, an aerostatic field is formed inside the layer. It has a large staticpressure gradient, in which the particles (grains) are separated only by their specific gravity, regardless of their size, absolute weight or shape. During the separator operation, of air flow has both the aerostatic and aerodynamic effect on the particles, which negatively affectsgrain separability. As a result of studies, the authors found that the optimal operation mode of the separator has the minimal speed of airflow through a layer of bulk sample, and the air pressure difference at the layer boundaries balances the grain layer.