Theoretical studies of the conical air separator

This article substantiates the relevance of the issue of modernizing machines for the fractional separation of grain materials. Currently, fractional separation of bulk materials using pneumatic equipment is a promising task, while there are difficulties in developing equipment of this type. Practice has shown that the available pneumoseparation units used in the agricultural and grain elevator industries are designed to separate light impurities and the main crop. Further separation of material with heavy impurities is usually carried out on sieves and sifters. Pneumatic cleaning systems provide a satisfactory quality of separation due to a number of affecting factors, the main of which are the midsection, which changes when the particle turns in the air flow, the unevenness of the air flow over the channel section, and others. The problem lies in the difficulty of providing a stable air flow, as well as the heterogeneity of the material. To improve the existing pneumatic machines, as well as to create fundamentally new ones, it is necessary to carefully study the theoretical issues of the process of fractional separation of bulk materials. The question arises of creating machines capable of separating bulk materials only with the help of air flow. It is proposed to develop a conical pneumatic separator, representing the truncated surface of the cone facing down. The working conical surface of the pneumatic separator includes three sectors. In the lower sector, heavy particles (grain of the main crop) roll down almost along the shortest (radial) trajectories and fall into the corresponding fraction. In the second section of the separator, the main fraction is located, which performs a rotational movement in one horizontal plane. Visually, this ring interferes with separation, overloading the installation. This ring can be removed by briefly disconnecting the fan from the power supply. As a result, the heap gets into heavy impurities, which is undesirable. In the upper sector, a light fraction stands out, having a small mass; it rises and goes into its fraction receiver. A mathematical model has been obtained that makes it possible to calculate the required air flow rate and design parameters based on the material used. The mathematical model also makes it possible to determine the presence and size of separation zones, which mainly depend on the geometric parameters of the cone and the dynamic parameters of the air flow. By changing the geometrical parameters of the cone (taper), the