Why are air induction nozzles called anti-drift?

Last updated on Jan 5, 2021 2 min read Application Technology

Image credit: Gabriel

The drift of phytosanitary products, besides bringing damage to the producers, can also bring risk to the environment, neighboring crops and the man. It is known and almost repeated as a mantra the ideal environmental conditions for spraying (temperature below 30°C 🌞, relative humidity above 60% 💧 and wind speed less than 10km/h 💨), but we know that these conditions are not maintained throughout the day and often the time interval for spraying is extremely limited, causing the spraying to be carried out under inadequate conditions, and thus the technicians instruct the use of tools that help reduce the risk of drift.

One way to reduce drift is by increasing the diameter of the droplets, that is, increasing the size of the droplets, drops smaller than 100Μm are easily dragged by the wind while larger drops of 500 Μm tend to have less problem of drift.

But why does a larger droplet diameter lessen the probability of drift occurrence?

Increasing the diameter of the drops, also increases the terminal velocity of the drops and the average life of them, decreasing the time that the drop takes to reach their target smaller will be the window of time that the wind has to drag this drop and also influences the potential Evaporation. The biggest problem of increasing the diameter of the droplets is related to the increase of the flow (L/ha), making it use a higher volume of syrup, that is, increases the use of water and makes the operation even longer. To circumvent this situation was developed tips with the induction of air (venturi system), these tips "inject" air into the drop, allowing the formation of large drops, with air bubbles inside, increasing