Atomization of dilute oil-in-water emulsions during application of crop protection products

Crop protection products are usually applied as sprays. These spray droplets have a certain size distribution. Fine droplets are often required to achieve a good coverage of the plant and to guarantee the biological efficacy of an agrochemical product. At the same time very fine droplets in spray are not desirable. Due to their low mass and velocity, these droplets can be carried from the application site by crosswind and e.g. can contaminate surface water. Droplet drift can be minimized by reducing the number of very fine droplets in spray. Dilute emulsions produce coarser sprays compared to water when atomized through a standard flat fan nozzle. For this reason dilute emulsions can reduce drift risk.

The mechanism of spray formation of dilute emulsions has been investigated in this thesis. The proposed mechanism also describes spray formation in more complex mixtures of dilute emulsions with surfactants or polymers.