螺旋排肥器排肥口参数对排肥性能影响的试验研究

针对螺旋排肥器在物料输送过程中排肥口物料流量随时间波动变化造成排肥均匀性降低的问题,该研究采用离散元仿真和台架试验相结合的方法,以排肥均匀性变异系数为评价指标,在螺旋转速30r/min下,研究了排肥口长度和排肥口角度对排肥均匀性的影响,通过正交试验分析了单个螺旋转动周期内的排肥特性。试验结果表明:影响螺旋排肥器排肥性能的主次因素分别为排肥口长度、排肥口角度,两者对螺旋排肥器的排肥稳定性和均匀性有非常显著的影响,在排肥口角度为135°、排肥口长度为60mm的组合下取得较优排肥效果,该组合下仿真试验的排肥均匀性变异系数为4.98%,台架验证试验的排肥均匀性变异系数为5.41%,仿真试验和台架试验结果吻合度较好。该研究可为螺旋式排肥器的设计与优化提供参考和理论依据。

Experimental study of the effects of discharge port parameters on the fertilizing performance for fertilizer distribution apparatus with screw

As an ideal execution mechanism for precise fertilizer distribution, the fertilizer distribution apparatus with screw is of great significance for precise fertilizer distribution. To solve the problem that the fertilizer flow rate at the discharge port of the fertilizer distribution apparatus with screw fluctuates with time during the fertilizer transportation process and the low fertilization precision, the orthogonal experiments and bench experiments, taking the variable coefficient of fertilization uniformity as the evaluation indexes, were carried out to study the influences of the discharge port parameters of the screw fertilizer distribution apparatus on the fertilization performance with the discrete element simulation and 3D rapid prototyping technology. The screw fertilizer distribution apparatus consisted of feeding inlet, screw, screw shell, discharge port. Firstly, A discrete element simulation platform was established to analyze the transient characteristics of the screw fertilizer distribution apparatus, the results showed that the lateral fertilizer method can reduce the low-frequency pulsation in the screw fertilizer process. Moreover, single-element tests with discrete element simulation of the discharge port angle and discharge port length were performed. The effective range of the discharge port angle and length were 120°-150° and 40-80 mm respectively according to single-element tests. Furthermore, the L18 (37) standard orthogonal table was used for the discrete element simulation and the bench test. The influences of two factors on the fertilization accuracy were studied, including the length of discharge port and the angle of discharge port and the interaction between the previous two factors. The fertilization characteristics of a single spiral rotation period are analyzed by orthogonal experiments. The results showed that the order of the main factors affecting the variable coefficient of fertilizer uniformity were the length of discharge port and the angle of discharge port, interaction between the previous two factors. The length of discharge port and the angle of discharge port had significant influences on the coefficient variation of uniformity of the fertilizer distribution apparatus with screw while the interaction between these two factors was not significant. The optimal combination of parameters was as follows: the length of the discharge port was 60 mm, the angle of discharge was 135°. The simulation results based on the optimal combination showed that the coefficient variation of uniformity was 4.98 %. The bench test was conducted to verify the optimal parameter combination results obtained by the orthogonal test. The bench verification test results showed that the coefficient variation of uniformity was 5.41 %, basically agree with the simulation result. This study can provide a reference and theoretical basis for the design and optimization of the fertilizer distribution apparatus with screw.