刮板输送式大棚有机肥排肥装置的设计与试验

目的 解决现有有机肥排肥装置排肥稳定性差的问题，提高大棚内有机肥施撒机械化水平，设计一种刮板输送式大棚有机肥排肥装置。方法 以苏南地区草莓种植大棚为例，依据大棚基本尺寸参数和草莓种植农艺要求，确定排肥装置设计的主要要求。结合散体力学理论对设计的排肥装置关键结构和参数进行分析和确定，确定影响排肥量稳定性的主要因素为排肥轴转速和排肥器开度。搭建室内有机肥排肥试验平台，进行转速与排肥量单因素试验和两因素五水平的响应面试验。结果 转速与排肥量相关性试验结果表明，在试验设定的转速和开度范围内，不同开度条件下，转速和排肥量均呈良好的线性关系，整体的决定系数大于0.9857，排肥量可通过实时调节开度和转速实现调节。响应面试验结果表明，排肥范围内排肥量稳定性较好，排肥轴转速对于排肥稳定性变异系数的影响大于排肥器开度。当排肥器开度为30.42 mm、排肥轴转速为51.5 r/min时，排肥稳定性变异系数结果最优，为1.84%。验证试验结果表明，变异系数相对误差不大于5%，变异系数相对误差均值仅为2.95%，符合要求。对比验证试验表明，常用的螺旋式有机肥排肥器的排肥稳定性变异系数均值为6.12%，本文设计的刮板输送式有机肥排肥器有效提高了有机肥的排肥稳定性。结论 设计的刮板输送式排肥装置具有较好的排肥性能，能够满足设施大棚内有机肥施肥作业要求。

Design and test of organic fertilizer discharging device with scraper conveyor for greenhouse

Objective In order to improve the mechanization level of organic fertilizer application in the greenhouse and solve the problem of low fertilizer discharge stability of the existing organic fertilizer discharging device, an organic fertilizer discharging device with scraper conveyor for greenhouse was designed.Method Taking the strawberry planting greenhouse in southern Jiangsu area as an example, the main requirements for the design of the fertilizer discharging device were determined according to the basic size parameters of the greenhouse and the agronomic requirements of strawberry planting. The key structure and parameters of the designed fertilizer discharging device were analyzed and determined by combining the bulk mechanics theory, and the main factors affecting the stability of the fertilizer discharging volume were determined to be the rotational speed of the fertilizer discharging shaft and the opening degree of the fertilizer discharging device. An indoor organic fertilizer discharging test platform was built, and single-factor test and two-factor five-level response surface test of rotational speed and fertilizer discharging volume were conducted.Result The results of the correlation test between rotational speed and fertilizer discharging volume showed that within the range of rotational speed and opening degree set in the test, the rotational speed and fertilizer discharging volume had a good linear relationship under the conditions with different opening degree. The overall coefficient of determination was above 0.9857, and the fertilizer discharging volume could be adjusted by adjusting the opening degree and rotational speed in real time. The results of the response surface test showed that the stability of fertilizer discharging volume within the set range was good, and the rotational speed of the fertilizer discharging shaft had a greater influence on the coefficient of variation of the fertilizer stability compared with the opening of the fertilizer discharging device. The coefficient of variation of fertilization stability was optimal (1.84%) when the opening degree of fertilizer discharging device was 30.42 mm and the rotational speed of fertilizer discharging shaft was 51.5 r/min. The comparison test showed that the average value of the coefficients of variations of the commonly used spiral organic fertilizer discharger was 6.12%, and the organic fertilizer discharger with scraper conveyor designed in this paper effectively improved the stability of organic fertilizer discharging.Conclusion The designed fertilizer discharging device with scraper conveyor has good fertilizer discharging performance and meets the requirements of organic fertilizer application in greenhouse.