DESIGN AND EXPERIMENTAL STUDY OF A SHAFTLESS DOUBLE-SCREW FERTILIZER SPREADER FOR RICE

To address the problems of poor fertilizer distribution uniformity and low application accuracy during the operation of rice fertilizer spreaders, this paper designs a shaftless double-screw fertilizer spreader for rice. Combining dynamic methods to analyze the filling stage and discharge stage of the fertilizer spreader, and investigating the impact of its structural parameters on the uniformity of fertilizer discharge. The fertilizer distribution process was simulated using EDEM software, and single-factor experiments were conducted to analyze the effects of spiral blade outer diameter, pitch, and rotational speed on fertilizer distribution uniformity. Furthermore, a two-factor orthogonal rotational combination experiment was carried out under different structural parameter conditions to analyze the interactions between influencing factors and determine the optimal parameter combination. The optimal parameters were found to be an outer diameter of 23.3 mm, a pitch of 23.6 mm, and a rotational speed of 149.2 r/min, yielding a uniformity coefficient of variation of 6.1%. Bench test results showed that the relative error between the simulation and experimental uniformity coefficient was 0.7%, indicating strong agreement. The results meet the agronomic requirements for fertilization and ensure stable fertilizer supply. These findings provide a reference for the design optimization of spiral fertilizer spreaders.