Optimisation of the design parameters of the control module of the air generator of an aerodynamic separator

The production of high-quality seed material and food grain required the use of efficient separation technologies. Aerodynamic separation was widely implemented in various designs of equipment intended for removing light impurities from the initial grain mass and dividing it into fractions that were uniform in their properties. The use of a differential airflow provided a relatively high 60-70% efficiency of grain cleaning from impurities. The study was aimed at investigating the efficiency of aerodynamic separation in order to identify ways to improve the quality indicators of the technological process of cleaning and calibrating the initial grain mass. Experimental investigations indicated that the airflow in the cross-section of the air channel of the SAD-4 model aerodynamic separator was non-uniform. Specifically, the airflow velocity in the lower third of the channel cross-section was 48-52% lower than in the upper and middle zones, between which the airflow non-uniformity amounted to only 7-9%. It was established that the intensity of the separation regimes affected the quality of the fractional composition. Under maximum operating settings, owing to the non-uniform distribution of airflow along the vertical plane, the heterogeneity of the fractional composition increased to 61%. The scientific problem of increasing the homogeneity level of the fractional composition of cleaned grain was proposed to be solved by modelling the airflow in the pneumatic channel of the aerodynamic separator in accordance with the operating settings. A design of an air generator with a mechanism for equalising airflow velocity in the cross-section of the separation channel was proposed. The investigations showed that when the operating settings were changed from “1” to “7”, the airflow intensity in the lower third of the channel cross-section varied from 1.9 to 12.6 m/s, which was 37-49% higher than in the serial separator. Under maximum separation regimes, the uneven distribution of the components of the initial grain mixture between fractions decreased to 25-29%. A functional relationship was established between the intensity and uniformity of the airflow in the separation channel and the homogeneity of the fractional composition of the cleaned grain