移动式温室风幕静电施药平台设计及试验

针对传统温室人工施药时,药量分配不均匀、农药大量浪费的现象,探索温室施药的新方式,以提高农药利用率和作业效率。根据温室作业环境,研制一种适应于温室的风幕式静电施药机具,确定整机结构方案及关键部件技术参数。以出口风速为试验变量参数,以覆盖率、沉积量、覆盖率均匀度和沉积量均匀度为评价指标,分析了出口风速参数对施药效果的影响。综合流体力学和机械设计知识,计算确定出风口间距0.5 m,出风口半径0.012 5 m,风机功率3 k W。实现了风送、喷雾量和喷雾高度可调,出口风速0-35 m/s可调,喷头流量0.2-1.0 L/min可调,喷雾高度1.15-1.95 m可调。试验结果表明,出口风速为25 m/s时,相对于其他风速,沉积量和覆盖率达到较好的值,均匀度分别稳定在85%和75%。与传统人工施药相比,风幕式静电施药的雾滴穿透性高,分散程度高,可避免重复施药和减少农药施用量。同时,合理的气流参数会进一步提高机具施药效果。

Design and test of air-assisted electrostatics prayer in greenhouse

In order to solve the problem of low efficiency utilization and non-uniform distribution of pesticide with traditional application sprayer in the greenhouse, a new spray model was investigated to improve the utilization rate of pesticide. According to the greenhouse environment, an air-assisted electrostatic greenhouse sprayer was designed which employed air-assisted and electrostatic technology. Coverage, deposition, and spray uniformity were used as indexes to research the effects of outlet air velocities on pesticide deposition in greenhouse. Based on the theory of the hydromechanics and mechanical design, structure parameters of the sprayer were determined according to: the interval between the air outlets was 0.5 m, the radius of the outlet was 0.012 5 m and the power of the fan was 3 kW. The outlet air velocity, spray amount and spray height could be adjusted within the range of 0-35 m/s, 0.2-1.0 L/min and 1.15-1.95 m respectively. Test results showed the optimum effect was obtained when the outlet air velocity is 25 m/s, under which deposition and coverage uniformity were steady at 85% and 75% respectively. Compared with the traditional manual spray pattern, air-assisted electrostatic spray model could achieve high penetrability and dispersion of droplets, which could avoid repeat spray and reduce amount. In addition, the spray effect could be improved under reasonable outlet air velocities.