Theoretical foundations for intensifying onion set harvesting

Abstract

The paper shows that upgrading the design of onion harvesting machines through the integration of diverse separation intensifiers demonstrates limited efficacy in improving the quality of cleaning commercial produce. They noted the need to comply with strict technological parameters for setting up separating systems (feeding bulbs to a straight section of the pin web surface in the absence of losses, reducing the maximum speed of collision of the bulbs with the working elements of the cleaning unit to reduce damage, as well as improving the completeness of cleaning). The study reveals that one of the options for intensifying the process of onion set cleaning from soil and soil clods can be ultrasonic-assisted heap moistening during separation. (Research purpose) The research aims to determine theoretical principles driving the intensification of onion set cleaning from mechanical impurities. (Materials and methods) The research employed system analysis and synthesis methods, physical modeling based on probability theory and  mathematical statistics, numerical techniques for solving analytical dependencies, classical mechanics methods - fundamental principles of fracture theory, soil mechanics. (Results and discussion) The paper justifies the necessary optimum regime for intensifying onion set harvesting and cleansing them from mechanical impurities. It substantiates the functional diagram of a digging-type onion harvester featuring an ultrasonic cleaning module, taking into account the functions of the state, external and control actions, as well as performance indicators. (Conclusions) The research resulted in developing a design concept for an ultrasonic-equipped separating module of a harvester to improve the onion set cleaning process. This design conforms to the agrotechnical requirements, ensuring maximum soil and impurity sieving (at least 98 percent), minimizing losses (not exceeding 2 percent) and bulb damage (not exceeding 2 percent).