Abstract

The present study concerned the wear of farm sprayer nozzles in practical operation and was conducted in order to answer following questions. * when do the nozzles become worn out? * which type of nozzle wears out the fastest? * do certain herbicides cause more wear than others? The Swedish Farmers Selling & Purchasing Association had requested its local branches to collect nozzles from farmers who had kept records of how they had been used. These records gave information on the type of herbicide, the number of seasons used and the spray rate. Altogether 42 sets of nozzles were used in the survey. Of these, 9 were made of brass (fan nozzles) and 33 of plastic (5 cone nozzles, 28 fan nozzles). The experimental equipment consisted of a patternator. The test was divided into two parts, the first dealing with determinations of the flow and the second dealing with the spraying uniformity. In the present study the total flow per nozzle was chosen as a measure of the nozzles range of use. As the original flows of the nozzles are not known, it is impossible to calculate the relative change in flow. This survey demonstrates that the change in flow is negligible within the sector in which the nozzles have been used. Neither do coefficients of variation for the flow change with the total flow. The coefficient of variation for the distribution increases with the total flow in the nozzle. A plastic fan nozzle is, on average, worn out after approximately 4000 l. In order to obtain a corresponding value for brass we have made an extrapolation (but its justification is doubtful). According to the extrapolation, the brass nozzles would wear out after approximately 14000 l (3.5 times more than plastic). The material was divided with regard to herbicides used into one group consisting of herbicides which form true solutions when mixed with water and another consisting of slurry herbicides and micro-suspensions. It is clear that the latter group is the most aggressive.

Keywords

spray nozzles; nozzle wear; nozzle material

Published in

Rapport - Sveriges lantbruksuniversitet, Institutionen för lantbruksteknik
1985,
ISBN: 91-576-2463-1
Publisher: Institutionen för lantbruksteknik, Sveriges lantbruksuniversitet

Permanent link to this page (URI)

https://res.slu.se/id/publ/125654