Development of a new vacuum chamber for a pneumatic seed separator

Improving the quality of seed material by selecting the best seeds for sowing, we can increase gross harvests. At the Department of Agricultural Machinery of Lugansk State Agrarian University, the author previously developed and assembled an experimental model of a pneumatic separator for seeds of vegetable and melon crops, the advantage of which is an increase in the quality of separation of flat seeds due to their positioning on a cylindrical support surface. In order to improve the quality of the new separator, a new vacuum chamber was developed, capable of increasing the uniformity of vacuum over the entire working surface. The authors performed a simulation of airflows and vacuum pressure distribution in the original and proposed sample of air chambers using SolidWorks Flow Simulation software. The aerodynamic calculation clearly demonstrated the advantages of the developed chamber. The developed model of the vacuum chamber was printed on a 3D printer from PETG plastic. In order to confirm the simulation results, an experiment was conducted to measure pressure drops in the new and original air chambers. Using the Testo 510i device, the author monitored the differences in vacuum pressure with a measurement frequency of once per second at a linear rotation speed of 0.5 cm/s with three retakes of the experiment. While processing the experimental data, the author took into account the averaged indicators for five possible trajectories of the seed movement in relation to the air chamber. According to the experiment results, it was found that when using the developed vacuum chamber, the average deviation of the vacuum pressure boundaries decreased from 11.70 Pa to 7.56 Pa. The overall accuracy of the experiment was 0.53%. Based on the research results, the developed rarefaction chamber will be integrated into the separator design.