Modeling of grain processing in a pneumomechanical dresser

Abstract

To improve the quality and effectiveness of pre-sowing treatment of seeds of grain crops, a hypothesis was put forward on the possibility of using the air flow to continuously perform a set of technological operations in the process of dressing. The proposed approach is implemented in a unrivalled pneumomechanical deresser, in the processing chamber of which a multiphase flow of dispersed mixture “air-seeds-droplet” is formed. For the theoretical justification of the main parameters of the processing process, a mathematical model of the movement of seeds and fine droplets of the working fluid was developed and numerically solved taking into account the decrease in their concentration along the length of the working chamber. As a result, it was found that the speeds of seeds and drops of different sizes as they move in the processing chamber naturally increase, and the concentration of drops decreases asymptotically. It was revealed that to ensure high quality processing at the entrance to the processing chamber, the seeds should move in suspension with the speed of the corresponding droplet speed of the working fluid. The minimum path length of the “air-seed-droplet” mixture is substantiated, where the maximum decrease in the concentration of drops occurs due to the adhesion of seeds suspended in the air flow to the surface. The results obtained are important for optimizing the length of the processing chamber, substantiating the modes and parameters of the movement of air, grain and drops, at which full coverage of seeds with a minimum flow rate of the working fluid is achieved. In the long term, the research results will serve as the basis for optimizing the design and technological parameters of pneumomechanical dressers, which ensure high quality and efficiency of pre-sowing treatment of seeds of grain crops.