Abstract: In order to overcome the bottlenecks of low efficiency in traditional tobacco plant topping and sucker control operations and the difficulty in flower top collection, and to improve the mechanization level of tobacco production in plain tobacco-growing areas, a pneumatic tobacco topping machine was designed to achieve the simultaneous operations of topping, sucker control agent spraying, and flower top collection. To address the problems of uneven airflow distribution within the chamber and the tendency of flower tops to collide and rebound, a flow field simulation analysis of the topping machine chamber was conducted using CFD software, and the internal airflow structure was optimized by adding streamlined guide vanes. The bench test results showed that the guide vanes effectively eliminated the low-velocity stagnant zones in the middle and upper sections, resulting in a more uniform airflow distribution, and that the cutter disc rotational speed had a significant effect on the operational performance; when the rotational speed was 600 r/min, the topping qualification rate reached 98%, the flower top collection qualification rate reached 96%, and the outlet airflow velocity reached 6.5 m/s, meeting the requirements of efficient pneumatic collection. The device featured a rational structure and stable operation, providing reliable equipment support and technical assurance for the full-process mechanization of tobacco plant topping and sucker control.

Key words: pneumatic, tobacco plant, tobacco, tobacco topping machine, design, flow field analysis, performance test, plain tobacco-growing area