OPTIMIZATION DESIGN AND TEST OF INTERACTIVE ANTI-STICK GEAR FERTILIZER DISCHARGER FOR PINEAPPLE

Based on the agronomic characteristics of pineapple fertilization and the challenges posed by moist fertilizer particle adhesion, an interactive gear fertilizer discharger was developed. This device utilizes a pair of continuously meshing, counter-rotating gears to achieve centralized and interactive mixing of fertilizer. Through theoretical analysis, the fertilizer discharge volume and maximum operating speed of the discharger were determined. In the experimental design, the pressure angle and helix angle of the fertilizer wheel were selected as test factors, while the coefficient of fluctuation in fertilizer uniformity served as the test index. A single-factor test was conducted to analyze the influence of each factor on the index and to determine the appropriate range of values. Subsequently, a quadratic general rotary combination design was used to optimize the fertilizer wheel parameters. The results indicated that both the pressure angle and helix angle had a significant effect on the coefficient of fluctuation of fertilizer uniformity (P<0.01). The lowest fluctuation coefficient, 11.82%, was achieved when both angles were set to 30°. A simulation verification test yielded a result of 11.92%, with a relative error of 0.85% compared to the theoretical value. Bench tests conducted under optimal parameters showed a relative error of 2.77% between the experimental and simulated values. Furthermore, the average error between the measured fertilizer discharge flow rate and the theoretical value under varying speeds was 3.75%. No fertilizer adhesion was observed on the surface of the discharge wheel, demonstrating that the system enables fine regulation of fertilizer output while effectively mitigating fertilizer adhesion.