两级螺旋排肥装置的设计与试验

为了改变现有排肥装置对肥料形态特征要求高的缺陷及改善排肥效果,该文设计了一种两级螺旋排肥装置,研究了装置的排肥原理,建立了排肥螺旋的单圈排肥量的数学模型,分析了两级螺旋排肥装置的相关参数,并通过试验测试与分析了两级排肥装置的排肥性能。试验结果表明,在10~200 r/min转速范围内,对于芭田复合肥、水稻专用肥及吸潮后的芭田复合肥和水稻专用肥,两级螺旋排肥装置每分钟内的排肥量随转速的增加而增大,并呈线性关系,整体决定系数大于0.998,排肥螺旋的单圈排肥量的极差、标准差及变异系数较小,对于含水率2%的芭田复合肥和含水率5.6%的水稻专用肥的单圈排肥量的变异系数小于0.025;吸潮后含水率较高的芭田复合肥和水稻专用肥的单圈排肥量的变异系数整体上不大于0.040。同时,通过数学模型计算出的单圈排肥量与实际单圈排肥量一致较好,该模型能准确表达此类两级螺旋排肥装置的单圈排肥量。因此,该研究能有效地改善排肥效果,降低对肥料形态特征的要求,为同步播种施肥机具及变量施肥机具的研究与设计提供了参考依据。

Design and experiment of fertilizer distribution apparatus with double-level screws

Abstract: In order to meet the physical requirements of fertilizer and improve fertilizing effects, a fertilizer distribution apparatus with double-level screws was designed. It mainly consists of a work bin, a screw of steady flow transportation, a fertilizing screw and a driving chain. The screw of steady flow transportation provides stable and adequate fertilizing flow for the fertilizing screw, mixes fertilizer and prevents fertilizer arching in the work bin, and ensures that the filling rate of the fertilizing screw is very close to 1. Through establishing mathematical models of per lap fertilizer amounts for the fertilizing screw, the fertilizing principle of fertilizer distribution apparatus with double-level screws was studied, and related parameters were analyzed as well. In addition, experiments were conducted to test and evaluate the working performance of the double-level screw fertilizer distribution apparatus. Three types of fertilizing screws were designed to meet the actual production requirements of fertilizing (20-100 kg/667m2) based on mathematical models. Test results show that, 1) In 10-200 r/min speed range, for Batian compound fertilizer, rice specific fertilizer, and Batian compound fertilizer and rice specific fertilizer after the absorption of moisture, the fertilizer amount per minute of the fertilizer distribution apparatus with double-level screws increases with increased speed, showing a linear relationship with a correlation coefficient of larger than 0.998. Therefore, the fertilizer distribution apparatus with double-level screws can adjust the fertilizer amounts by varying the speeding of fertilizing screw to meet the requirements of different fertilization. 2) In 10-200 r/min speed range, the standard deviation, range and variation coefficient of the per lap fertilizer amounts are relatively small for 3 types of fertilizing screws. The variation coefficient of the per lap fertilizer amounts is less than 0.025 for Batian compound fertilizer with the moisture content of 2% and the rice specific fertilizer with the moisture content of 5.6%. The overall variation coefficient of the per lap fertilizer amounts is not more than 0.040 for Batian compound fertilizer and rice specific fertilizer with higher moisture after the absorption of moisture. The fertilizer distribution apparatus with double-level screws has a better adaptability and good fertilizing effect for above 5 types of fertilizers in 10-200 r/min speed range. 3) In 10-200 r/min speed range, by comparing theoretical fertilizer amount per lap and theoretical filling rate with actual values, respectively, mathematical models of the per lap fertilizer amounts of the fertilizing screw was verified and confirmed. This study can effectively improve the fertilization effect, reduce the fertilizer requirements of morphological characteristics and provide a reference for the research and design of synchronous sowing and fertilizing machine and variable-rate fertilization machine.