Authors

Abstract

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.

Abstract in Chinese

根据菠萝施肥的农艺特性以及潮湿肥料颗粒粘连问题，设计了一种交互式防粘齿轮排肥器，其采用一对持续啮合反向挤压旋转的齿轮实现肥料的对中交互混排。针对尿素颗粒肥料受潮易于粘结、结块的特性。通过齿轮啮合作用，使得因潮湿而粘连在排肥齿轮上的肥料因挤压力得以脱落。通过理论分析确定交互式齿轮排肥器的理论排肥量与最大转速，利用EDEM软件对排肥过程进行仿真模拟。以排肥轮的压力角和螺旋角为试验因素，以排肥均匀性波动系数为试验指标，通过单因素试验分析试验因素对试验指标的影响，并确定试验因素的范围。通过二次通用旋转组合设计试验优化出排肥轮的最优参数。试验结果表明：排肥轮压力角和螺旋角对排肥均匀性变异系数均有极显著影响（P＜0.01），当排肥轮压力角和螺旋角均为30°时，排肥均匀性变异系数最小为11.82%。仿真验证试验结果为11.92%，相对误差为0.85%，最优参数下的交互式防粘齿轮排肥器台架试验结果表明：试验值与仿真值的相对误差为2.77%，排肥流量可通过排肥轮转速线性调节，排肥轮转速流量曲线方程为：y=0.74x+1.39，通过反转啮合齿轮的啮合，齿面间的挤压作用可降低肥料对排肥轮的粘连。其结果表明：在排肥轮转速流量转速曲线下排肥排肥器流量与理论值平均误差为3.75%，即使用转速流量曲线可实现对排肥量的精量调控；通过重复试验发现排肥轮表面并无粘结肥料，即交互式防粘齿轮排肥器可消除其肥料对排肥轮的粘连作用。