Study of Performance Characteristics of the Gravitational Guide Curve of Feeder Unit

The rate of the feed velocity and specific load in the air separator are interrelated and require a rational approach to their choice, because reducing the rate of velocity increases grain flow thickness, which adversely affects the efficiency of grain separation in the separation zone, but limits separator performance. Based on the research of many authors, it was concluded that the feed velocity of grain material into the pneumatic separation channel should be in the range of 0.4… 0.6 m/s. Taking into account that using a feeder unit for multilevel grain input, the total thickness of grain flow is divided by the number of the involved levels of input. The main condition is to ensure a single layer of grain feed at the velocity at which the most intense release of light impurities. Therefore, the purpose of the study is to identify rational parameters of the guide gravitational surface of the feeder unit with the provision of appropriate performance characteristics of the grain flow during its multilevel feeding into the pneumatic separating channel. As a result of experimental research, the dependences of the modes of movement of grain material on the gravitational guide curve on its main parameters, namely, the length of the acceleration section Lp, its angle α and the radius of the arcuate section r. On the basis of the carried-out research parameters of a gravitational guide surface at which a single-layer mode of movement of grain material for a range of specific loadings is reached are established qB = 250 – 500 kg/hour. Accordingly, for the conditions of movement of grain material with a thickness of one grain with the velocity of feeding into the pneumatic separation channel vв = 0.5…0.6 m/s, the rational parameters of the guide gravity curve for cereals with the internal friction coefficient φтер = 0.47…0.73 there are: the length of the acceleration section Lp = 0.2 m, the angle of its inclination α = 33° and the radius of the arcuate section r = 0.15 m.