127 / 220
臺灣農藥噴頭與飄散研究
125
Investigation of How Various Pesticide Spray
Nozzles Affect Droplet Size and Spray Drift
Yu-Rong Huang
1
* , Rong-Jhih Syu
1
, Ming-Hsun Ho
1
Abstract
Huang, Y. R., Syu, R. J., and Ho, M. H. 2016. Investigation of how various pesticide spray nozzles affect
droplet size and spray drift. Taiwan Pestic. Sci. 1: 107-126.
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
μ
m). 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
μ
m 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
Accepted: September 9, 2016.
* Corresponding author, Email:
huangyr@tactri.gov.tw1
Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture. Taichung.