气吸式小浆果捡拾输送装置参数优化

为了获取气吸式小浆果捡拾输送装置的输送特性及其输送管较佳管径尺寸，该文以黑加仑果实（布劳德品种）为研究对象，运用空气动力学相关原理，计算得到黑加仑果实在输送管中适宜的风速范围为5～73 m/s；通过EDEM-FLUENT软件耦合方式对输送装置进行建模和仿真，对输送管内气体压力云图及压降进行分析，对比分析3种不同管径输送管（32、40和50 mm）的输送效率及输送过程中的破果率；进一步在自制的黑加仑捡拾输送装置上进行试验。试验结论与仿真结果均表明输送管的较佳管径为40 mm，并得出输送效率、破果率与气体流量之间的回归方程（R2均大于0.9），论文结论可为气吸式小浆果采摘机具研发提供参考。

Parameter optimization of air-suction collecting and conveying equipment for small berry

Currently, researches both in domestic and oversea on fruit harvesting machine mainly focus on vibrating type, and making fruit separated from plants through vibration. Most of the related studies and reports of fruit harvesting machine are aimed at recovery efficiency, while the studies of small berries collecting and transportation are still relatively rare. In order to solve harvesting problem of small berry and figure out transmission characteristics of the air-suction conveying equipment, especially to get the best dimension of the conveying pipe diameter, this paper attempts to optimize the parameters of small berries collecting conveyer with blackcurrant (broad variety) as the research object, and thus confirms the optimal diameter size of the pipeline. First of all, based on the physical properties of the fruit blackcurrant, the suspended velocity is about 5 m/s by resorting to aerodynamic and other related theory. In order to prevent blackcurrant fruit movement from being too fast to fracture, the maximum wind speed is about 73 m/s by means of analyzing and calculating. Therefore, the suitable wind speed range of blackcurrant fruit movement in the conveying pipe is nearly 5-73 m/s. Secondly, using coupling EDEM- FLUENT software for modeling and simulation of conveying equipment, the gas pressure contours of 3 kinds of conveying pipes with different national standard diameter were analyzed, and it was concluded that air pressure inside the pipeline reduced gradually with the air flow direction. Through calculating the pressure drop to compare the conveying efficiency of 3 kinds of pipelines with different diameter, the pressure drop ofφ40 pipe was larger than the remaining pipes, which meant that theφ40 pipe had a higher transmission efficiency than the remaining pipes in the same flow. According to the results, the value of the maximum force for theφ40 pipe which broke through critical point was less than the remaining pipes during the process of conveying, and the fruit breaking rate of theφ40 pipe was low using the software to monitor the maximum force of blackcurrant fruit in the conveying pipe. Finally, we designed and made the experimental device of blackcurrant collecting and transmission. The conveying efficiency and fruit breaking rate of 3 kinds of pipelines were tested under different gas flow, and the test results were statistically analyzed. With the increase of gas flow, the conveying efficiency and fruit breaking rate of 3 kinds of pipelines accordingly increased. Under the same gas flow, the transmission efficiency ofφ40 pipe is high. When the flow increased, the transmission efficiency grew rapidly. When the gas flow rate increased, only the growth rate of fruit breaking rate ofφ40 pipe gradually slowed. The regression equation of conveying efficiency and fruit breaking rate with the flow conformed to the law of quadratic curve and the regression coefficient was greater than 0.9. The result presents that the best inside diameter of pipeline is 40 mm, and the conclusion also provides the reference for research and development of other small berry picking machines.