Comparison of the droplet size spectra produced by rotary atomizers and hydraulic nozzles under simulated aerial application conditions

Abstract

A wind tunnel was used to characterize the droplet size spectra of liquid sprays from several different atomizers and nozzles used under simulated aerial application conditions. The atomizers included a D8–46 nozzle, a Through Valve Boom (TVB) nozzle, and rotary cage and drum atomizers.

The D8–46 hydraulic nozzle was evaluated, using water, at orientations of 0, 10, 20, 30, 40, 50, 60, 70, 80 and 90° relative to 145 and 180 km/h airstreams. The TVB nozzle was evaluated using water, water with isopropyl alcohol, and water with a non‐ionic surfactant at airstream velocities between 130 and 180 km/h. The rotary atomizers were evaluated at different rotation rates, flow rates of water and an insecticide, in 130 and 180 km/h airstreams.

The volumetric droplet size spectra parameters (D_vo.x) decreased as the angle of the D8–46 nozzle and the airstream velocity increased. Empirical models were developed to predict these values for different windspeed and nozzle angle conditions. The TVB nozzle produced larger droplets than the other atomizers under similar conditions, with a decrease in the D_vo.x parameter values as the airstream velocity increased.

The D_vo.x parameter values produced by the rotary atomizers increased as the liquid flow rate increased, and as the rotation rate and airstream velocity decreased, and were lower for the insecticide than for water. The slotted rotary drum atomizer gave the best control over droplet size, generally producing mono‐modal droplet size spectra where the other atomizers often produced bi‐ and multimodal spectra.     

略论环境管理模式的重大变革——ISO14000系列标准剖析

国际标准化组织（ＩＳＯ）根据环发大会的决议，１９９３年６月正式成立“环境管理技术委员会”（ＩＳＯ／ＣＴ２０７），负责环境管理工具及体系方面国际标准化工作。文章通过对ＩＳＯ－１４０００系列标准的背景和内容的介绍与分析，阐述了目前在我国实施ＩＳＯ－１４０００系列标准的意义和对策。建议。