臺灣農藥噴頭霧滴粒徑調查研究與飄散評估方法建立

Investigation of How Various Pesticide Spray Nozzles Affect Droplet Size and Spray Drift

黃郁容(Yu-Rong Huang) ； 徐榮志(Rong-Jhih Syu) ； 何明勳(Ming-Hsun Ho)

《臺灣農藥科學》 1期 (2016/12) Pp. 107-126

https://doi.org/10.6671/TPS/2016.001.06

摘要

臺灣目前使用的農藥噴頭種類繁多，由於尚未有統一的規格，本研究初步收集農民常用的9 種噴頭，包括4 種白鐵扇形及5 種黃銅 ( 含單孔及多孔) 圓錐噴頭，測試2、7、10 及20 kg/cm2等農民常用之壓力範圍下之霧滴粒徑及流量，以瞭解目前臺灣常用噴頭的一些基本資料，並建立一套評估霧滴飄散的方法，以瞭解現今農藥噴灑可能造成的飄散情況。由本次9 種噴頭霧滴粒徑分析結果顯示，4 種白鐵扇形噴頭霧滴粒徑皆較黃銅圓錐噴頭細，且外觀標示為「5」的三種噴頭粒徑相似，2 kg/cm2 時約106.2 ~ 114.5 μm，而9 種噴頭在壓力從2 kg/cm2 提高到7、10 kg/cm2 後霧滴細化就逐漸趨緩，因此在提高壓力到20 kg/cm2，對霧滴粒徑變化的幅度就開始減小，而黃銅噴頭因為有單孔及多孔的噴頭，霧滴粒徑變化較複雜，多孔噴頭流量大，亦有壓力到7 或10 kg/cm2 後霧滴細化就逐漸趨緩現象，惟本次收集的五孔內牙噴頭其霧滴粒徑Dv(50) 在不同壓力下幾乎相似 ( 介於118.0 ~ 128.5 μm)，只有Dv(90) 在壓力2 kg/cm2 提高到20 kg/cm2 時，粒徑從221.7 μm 降為169.2 μm 左右，顯示不同壓力下對此一噴頭霧滴大小平均粒徑變化影響不大。此外，為了瞭解臺灣常用噴頭在田間使用時的飄散距離，建構了飄散模擬的控制環境進行測試，初步以農民田間常用的其中一種白鐵扇形噴頭KS K-5，模擬低壓 (3 kg/cm2)向下噴施地面栽培作物 ( 屬非常細霧滴) 之飄散情況，顯示於風速1 m/s 時飄散距離達到3 m，再將風速提高至2 m/s 以上後，飄散距離已達5 m 以上，若提高到田間慣用的10 ~ 20 kg/cm2則飄散情況可能會更趨嚴重。再者，將單孔的白鐵扇形噴頭依ISO 10625 以流速進行分級，結果4 支噴頭流速接近01 或015，但流速規格未符合5 % L/min 誤差範圍，皆介於01 ~ 015 之間，其餘噴頭因為屬多噴孔或可調整流量，僅作為流量比較參考；再依據ASABE S572.1 將這9 種噴頭於不同壓力下霧滴粒徑進行分類，結果顯示僅2 種黃銅圓錐噴頭在2 kg/cm2 使用時為細 (F)霧滴，其他皆為非常細 (VF) 霧滴，再提高到農民慣用的7、10 甚至20 kg/cm2，全變成非常細 (VF)的霧滴，因此可能對於霧滴飄散具有很大的影響。綜合以上，本次測試的9 支農民常用噴頭，霧滴粒徑在低壓2 kg/cm2 就多呈現為非常細霧滴，因此以目前田間慣用的10 ~ 20 kg/cm2 甚至更高壓，更是可能造成飄散的危害，後續會再累積不同常用噴頭的基本資料及飄散結果，以利作為飄散評估背景資料的參考佐證。

關鍵字

噴頭 ； 飄散 ； 流量 ； 粒徑分布

並列摘要

In this study, we tested nine different spray nozzles used in Taiwan (including 4 stainless steel fan nozzles and five brass cone nozzles) to (1) improve understanding of droplet size and flow rate under 2, 7, 10, and 20 kg/cm^2 of pressure and (2) establish a method to evaluate spray drift. From size distribution data of nine nozzles, the droplet size of stainless steel fan nozzles were smaller than that of brass cone nozzles. Three (labeled No. 5) out of the 4 stainless steel fan nozzles that we tested showed similar droplet sizes (approximately 106.2 to 114.5 μm). Furthermore, we found that droplet getting smaller with higher pressure operation, but stop changing size when pressure achieved 10 kg/cm^2. One of the brass nozzles (5 hole-inner thread) showed a similar size range between 118.0 and 128.5 μm within 2 to 20 kg/cm^2 of pressure, indicating that operation pressure has little influence on droplet size with this nozzles of multi-hole. In order to estimate spray drift distance by using nozzles available in Taiwan under the practical field condition, we used KS K-5 stainless steel nozzles (classified as very fine droplet size) to imitate the downward spray typically used for ground crop. This provided a spray drift of 3 meters at a wind speed of 1 m/s and a spray drift of 5 meters at a wind speed higher than 2 m/s. It might cause more serious spray drift when using high pressure operation that often used in the field. We also classified the 4 stainless steel fan nozzles by flow rate (based on ISO 10625), they were similar to 01 or 015 specification but not exactly the same (out of 5% L/min relative tolerance). In addition, when the droplet size of all nine nozzles was classified based on the ASABE S572.1 standard, only two brass nozzles were found to have fine (F) droplets at 2 kg/cm^2; the other seven nozzles showed very fine (VF) droplets. All nine nozzles showed very fine droplets at pressure of 7, 10 and 20 kg/cm^2, thus these nine nozzles can produce very fine droplet size which can lead to spray drift. In future research, we plan to collect data pertaining to droplet size, flow rate and spray drift distance for additional spray nozzles used in Taiwan in order to continue our evaluation of spray drift.

並列關鍵字

spray nozzle ； spray drift ； flow rate ； droplet size distribution