新型扇形雾射流喷头雾滴沉积和飘移潜力特性研究

Study on Droplets Deposition and Drift Potential of Typical Different Flat Fan Nozzles

为合理选用喷头,提高农药有效利用率,减少流失、飘失,应用激光雾滴粒径分析仪和改进后农药雾滴沉积飘移测试平台,依据ISO24253-1田间喷雾沉积试验测试标准和ISO22369-3农药飘移潜力测试平台标准,对具有代表性的德国Lechler公司生产的射流(IDK系列)和双扇面射流(IDKT系列)新型大雾滴扇形雾喷头在不同喷雾压力(0.2、0.3、0.4 MPa)下的雾滴谱、雾滴裸地沉积分布和雾滴飘移潜力进行测试研究,并与常用标准扇形雾喷头Lechler ST、LU系列喷头进行对比。结果表明:随喷雾压力增大,标准扇形雾喷头和射流喷头均雾滴粒径变小,雾滴谱变宽,雾滴直径小于100μm,V100增大。ST系列的雾滴谱比LU的宽,IDKT的雾滴谱比IDK的宽。标准扇形雾喷头(ST和LU)雾滴为细雾和非常细雾,射流喷头(IDK和IDKT)雾滴为中等雾和粗雾。喷头雾滴粒径决定了雾滴的沉积和飘移特性,在相同喷雾压力条件下,同种型号喷头雾滴裸地沉积量IDKT120>IDK120>LU120>ST110,射流喷头雾滴沉积量显著高于标准扇形雾喷头(P<0.05),所测喷头雾滴沉积变异系数均低于8.5%。随着喷雾压力增加,喷头雾滴的飘移量均增加,喷雾压力对标准扇形雾喷头雾滴飘移影响更加明显,但对射流喷头不明显。在相同喷雾压力条件下,射流喷头雾滴飘移量远小于标准扇形雾喷头,各喷头雾滴飘移量均随雾滴收集距离增大而呈现减小趋势,且飘移均主要集中在测试平台前5 m处。射流喷头IDK和IDKT之间DPV无显著性差异,但标准扇形雾喷头DPV显著高于射流喷头(P<0.05),射流喷头与ST喷头相比,相对防飘能力均在55%以上。上述结果将有助于种植户和生产企业选择最佳喷嘴类型,以提高药效,减少农药喷雾漂移。

In order to select the reasonable nozzle and improve the effective utilization rate of pesticide, reduce the loss and drift, this paper evaluated standard flat fan nozzles(Nozzle type: ST and LU) and venturi flat fan nozzles(Nozzle type: IDK and IDKT) from Lechler Company by droplet diameter, deposition and drift risk,using Laser Particle Size Tester and the developed test bench according to ISO24253-1 and ISO22369-3 in different spray pressures(0.2, 0.3, 0.4 MPa). The results indicated that with the increase of spray pressure, standard and venture flat fan nozzle’s droplet diameters all became smaller, relative spectrums(RI) turned wider, droplets was below 100 μm in diameter, and V100 increased. ST’s RI was wider than that of LU, and IDKT’s RI was wider than that of IDK. Droplet sizes of ST and LU nozzle types in this study were fine and very fine, while IDK and IDKT’s droplet sizes were medium and coarse. Droplet size determined the droplet deposition and drift characteristics. In the same spray pressures, the deposition amount of the same kind of droplet on bare ground was IDKT120 > IDK120 > LU120 > ST110. The depositions of IDK and IDKT were significantly higher than those of ST and LU nozzle types(P<0.05), and the coefficient of variation of deposition of droplets were all less than 8.5%. With the increase of spray pressure, the amount of droplet drift increased, and the spray pressure had more effects on the droplet drift of the standard fan nozzle, but there were not obvious effect on that of the jet nozzles. Under the same spray pressure, the droplet drift rate of the jet nozzle was far less than that of the standard fan nozzle, and the droplet drift volume of each nozzle decreased with the increase of droplet collection distance, and the drift was mainly concentrated at the top 5 m of the test platform. Drift potential values(DPV) obtained showed newly designed Venturi flat fan nozzles IDK and IDKT could significantly reduce the drift potential(P<0.05), in comparision with standard flat fan nozzles ST and LU, drift reduction value reached to more than 55%. Above results were helpful for growers and industry to select the best nozzle types to increase efficacy and to reduce pesticide spray drift.