Influence of Surface Tension of Water on Droplet Size Produced by Flat Jet Nozzles

Abstract

The aim of the study was to check if the quality of water which was taken from different sources (used for plant protection treatments) influences the droplet size generated by agricultural nozzles. The experiment was done in the laboratory of the University of Life Sciences in Lublin (UP Lublin), and water from 3 different sources was used, demineralized water was used as reference water. There were two treatements of adjuvant (Superam 10AL): with and without adjuvant. The water quality was assessed on the basis of the change of surface tension. The surface tension was measured with a drop Shape Analizer DSA30 device. The Flat Fan, one of the agricultural nozzles widely used by farmers, was used in the study. The measurement was done with spraying pressure of the following values: 2 bar, 3 bar and 4 bar with three repetitions. The droplet size was measured with a laser diffractometer HELOS/R-Sympatec. The results show that using the adjuvant changed the surface tension for all the types of the water sources. However, this change was higher for the water from the farm well (source B) and the tap water from UP Lublin building (source C). This change in the surface tension alters in turn the drops size (Volume Median Diameter) depending on the average results of the spray patteren, but only when using 3-bar pressure.

Effect of liquid surface tension coefficient on spray cone structure of ejection sprayer

“…A limited number of works [7][8][9][10], in which the process of liquid dispersion by jet nozzle is mainly considered, have been devoted to the study of the effect of changes in the surface tension coefficient on the spray cone structure. It has been determined that the surfactants are incorporated into water leads to a decrease droplet size in the spray cone, but at the same time, the process of disintegration of various solutions water with surfactants does not change and remains similar to the disintegration of "pure" water.…”

Spectrum of spray droplets with different nozzles and adjuvants

“…Technical specifications with the droplet size ranges are found in the catalogs, but they can change according to the spray solutions physical characteristics, environmental conditions, machinery engineering, used methodology, among others (Yan et al, 2017;Carvalho et al, 2017;Parafiniuk et al, 2017;Carvalho et al, 2018). Choosing the droplet pattern is important, as it directly influences the coverage of the target and risks of drift losses (Mota & Antuniassi, 2013).…”