For comparison, a human hair ranges from 20 to 180 µm. Most electrostatic nozzles produce ~50 µm droplets, categorized in agriculture as Very Fine. Droplets must be large enough to resist evaporation and drift but small enough that the charge can change their trajectory when it comes close to a target (I.e., the Charge-to-Mass Ratio). Droplet Sizeĭroplet size is a critical factor. The clearance between the droplets and the plates is quite large in relation to that in a twin-fluid atomizer, coil-type charging system. As they approach such an object, the negative charge on the droplet surface repels mobile electrons on the surface of the target, which redistribute, creating a relative positive charge on the surface and attract the droplet.Īnother style of electrostatic technology employs a highly charged plate along the air outlet of the sprayer, generally attached just inside the duct. The droplet now has its own field that electrically motivates it to land on neutral objects. The field attracts electrons to the droplet surface and repels positrons towards the centre. The droplet becomes polarized when it passes through the electric field. Let’s consider a negatively-charged droplet (see diagram below). The latter has the added advantage of blowing droplets away from the electrode and projecting them into the canopy. a hollow cone) and sometimes using an air-shear nozzle. Sometimes the spray is atomized by a hydraulic nozzle (e.g. Think of it as high-voltage static electricity. An intense electric field imparts a positive or negative charge depending on the polarity of the DC power used. This is referred to as coronal discharge. Commonly, the charge is induced by an electrode positioned close to the atomizing spray plume as droplets begin to form. Spray is charged by a high voltage supercharger. But first, read this article which explores the basic principles behind how electrostatic applications work. That article might help answer the question.
So it begs the question: “Why doesn’t everyone have an electrostatic sprayer?” We performed a study in carrot in Ontario’s Holland Marsh to explore some of the claims and to get a first-hand experience with the technology. Improved efficacy with both insect and disease control.Improved retention (>50% better than conventional) and/or potential savings of 50% spray mix.underleaf coverage, panoramic stem coverage and canopy penetration). Independent research, manufacturer claims and user testimonials are intriguing: