Development of drift reduction technology for field boom sprayers

本文对喷雾作业进行了研究，并通过风洞试验分析了喷雾漂移机理，开发了现场臂架喷雾器减少喷雾漂移的技术。每年5月到8月，德胜的农民都在忙着做害虫防治工作。他们通常在风速较低的清晨和傍晚进行操作。大型农户在高效喷雾器的使用上比较先进，有拖车式和自行式，应用宽度在20米以上。风是影响农药防治病虫害时机的因素之一。因此，农民希望使用即使在温和到强风条件下仍然可以操作的漂移喷雾减少技术。随着喷雾颗粒变小，漂移距离的对数线性增加。随着喷雾颗粒的排出速度变慢，它也会增加。对于常规喷嘴，在喷流高度为40 cm，风速为1 m/s时，漂移开始呈指数增长。然而，当使用无漂移喷嘴时，漂移减少了。不到传统喷嘴的一半。在无风条件下，喷雾分布模式向喷嘴方向延伸。2 .当有风时，下风侧漂移增大，在长臂的喷雾器中，有必要使用自动控制装置，以保持应用高度恒定。使用臂架高度控制器和选择无漂移喷嘴，使传统喷雾器的喷雾漂移降低了近70%。这项技术使得在风速高达2.8米/秒的条件下进行喷雾成为可能。因此，该技术在减少喷涂作业中的漂移方面非常有效。

This research was conducted to investigate spray operations, to analyze the spray drift mechanism by wind tunnel experiments, and to develop the spray drift reduction technology for field boom sprayers.1. From May to August every year, farmers in Tokachi are busy doing pest control operations. They usually do the operation in the early morning and evening when the wind velocity is low. Large-scale farmers are more advanced in the use of high-efficiency sprayers, the trailer and self-propelled types , with application width of 20 m or more. The wind is one of the factors that disturb the timing of the application of chemicals to control pests and diseases. Therefore, farmers desire to use drift spray reduction technology that can still be operated even in mild to strong wind conditions.2. The logarithm of the drift distance linearly increases, as the spray particles become smaller. It also increases, as the discharge velocity of the spray particles becomes slower. For conventional nozzles, the drift increases exponentially beginning at the application height of 40 cm and wind velocity of 1 m/s. However, when driftless nozzles were used, the drift was reduced. to less than half to that of the conventional nozzles. At no wind condition, the spray distribution pattern extends to the direction of the nozzle. When there is a wind, the drift in the leeward side increases, in sprayers with long boom, the use of automatic control device is necessary to keep the application height constant.3. The use of the boom height controller and the selected driftless nozzle decreased the spray drift of the conventional sprayers by almost 70%. This technology made it possible to spray at wind velocity condition of up to 2.8 m/s. Therefore, the technology is extremely effective in reducing the drift in spraying operations.