The influence of drift reduction agents and wind speed on spray drift in the wind tunnel

Due to wind-induced dispersion of the spray liquid higher costs are incurred, pollutes the environment and may cause adverse effects on human health. To reduce the negative influence, preparations with anti-drift properties are increasingly being investigated. Therefore, the aim of the study – to analyse the efficiency of the new developed drift reduction agents at different wind speeds.

Trials of drift reduction solutions were carried out in open circuit type wind tunnel which was developed to study the drift from the sprayer nozzle under controlled and repeatable environmental and spraying conditions. Solutions were spread at two different wind speeds (8 m s^-1 and 10 m s^-1). The chambers were 5 m long in total. An air-injector nozzle was used during trials. The spray pressure was 4.0 bars.

The trials were performed with water (control) and two solutions (DRA-1 and DRA-2) in which the main part of the active substance of 0.1% concentration was calcium dodecylbenzenesulfonate CDS (50%) and butanol (18%). In both solutions, one of the active ingredients was polyether-modified trisiloxane PMT. Polyether-modified trisiloxane concentration was 0.06% in solution DRA-1 and 0.10% in solution DRA-2. A total of 30 L of each solution was sprayed. Tests were repeated three times.Summarizing the research, it can be stated that when the wind speed was 8 m s^–1, experimental DRA-2 solution drifted about 46% less than water and about 17% than other DRA-1. When the wind speed reached 10 m s^–1, experimental DRA-2 solution drifted about 30% less than water and similar with other DRA (DRA-1). The reason for this is a solution of a substance DRA’s restricting the small droplets that are the most exposed to the wind.