果园管道恒压喷雾雾滴均匀性试验与分析

Test and analysis of droplet uniformity for pipeline constant pressure spray in orchards

雾滴均匀性是衡量喷雾效果的重要指标之一,探索管道恒压喷雾中压力和孔径对空心圆锥雾喷头雾滴均匀性的影响具有重要意义。通过喷雾性能综合试验平台,利用激光粒度仪,测量管道恒压喷雾中3种孔径空心圆锥雾喷头在8种压力下的5种雾滴均匀性参数数据,获得雾滴累积分布,分析雾滴的分布和均匀性。结果表明,在本试验压力范围（0.70~1.40 MPa）下,雾滴粒径较一致,雾滴较均匀;当压力大于0.80 MPa时雾滴均匀性很好;压力越大、孔径越小,雾滴越均匀;D〈20 μm的雾滴（均小于0.538%）和D≥100 μm的雾滴（均小于0.325%）可忽略不计,主要为D〈60 μm的雾滴（90.132%~99.234%）,扩散比为0.893~0.916;5种均匀性参数均随压力呈二次多项式变化规律,R2均在0.984以上;5种均匀性参数与孔径和压力均有良好的二元线性关系（R2分别为0.952、0.952、0.937、0.850和0.831）。结果验证了管道恒压喷雾装置有助于提高雾滴均匀性,对管道恒压喷雾中喷头的选型、喷雾压力的设置及喷雾效果的优化有重要参考意义。

Droplet uniformity is one of the key measures of spray effect,and it is important to study the influences of pressure and pore diameter on droplet uniformity of hollow cone nozzle in pipeline constant spray. Two important aspects were researched with spray performance by test platform and laser particle analyzer,five parameters of droplet uniformity under three types of pore diameter and eight types of pressure were mearsured to get the cumulative distribution of droplet,and analyze the distribution and uniformity. The results showed that,under the testing pressure （0.70-1.40 MPa）,droplet diameter was consistent and droplet was uniform. When the pressurewas more than 0.80 MPa,the spray effect was very high. The higher the pressure was,and the smaller the pore diameter of nozzle was,the more uniform the droplets would be. Droplets with diameter less than 20 μm（ 〈0.538%） and more than 100 μm（〈 0.325%） could both be neglected,and the main droplets diameter was less than 60 μm （90.132%-99.234%）. Diffusion ratio of droplets was 0.893-0.916. The relationships between five types of droplet uniformity parameters and pressure could all be described by quadratic polynomial equations（ R2 were all more than 0.984）,and meanwhile,five types of droplet uniformity parameters influenced by pressure and pore diameter could all meet the binary linear equations（ R2 was 0.952,0.952,0.937,0.850 and 0.831）. The results verified that pipeline constant pressure spray could improve droplets uniformity,and meanwhile they provided valuable references for selecting nozzle,setting spray pressure and optimizing spray effect of pipeline constant pressure spray in orchards.