Eurofoil and the small droplets
The spray concept of the future
The Eurofoil atomizer was first introduced in 1999 as a successor to the familiar danfoil atomizer. The Eurofoil atomizer was developed based on experiences from danfoil customers and research institutions and provides a number of advantages relative to conventional nozzles.
Eurofoil atomizer is patented
In the general public, surprise is often expressed, that the danfoil atomizer, which produces many small droplets, not simultaneously provides the basis for large drift. Generally, small droplets are very sensitive to wind. To this danfoil a/s has always answered, that both experiments, and the daily work in the field, has shown that danfoil field sprayers does not leave much drift. However, it is assumed that the sprayer is operated after the provided and simple instructions. In the following we will try to explain this.
During the development stage of the Eurofoil atomizer, the atomizers droplet spectrum, at different air pressures, has been analyzed. This has happened at The Faculty of Agricultural Sciences (DJF), Research center Bygholm, Horsens. The survey was conducted with a TeeJet Nozzle XR 110-04 flat fan nozzle as a reference.
Analyses include a situation where it is most likely to drift, namely when sprayed on bare ground or weed spraying of low plants. In their experiment, Research center Bygholm concluded:
- That Eurofoil is producing a larger number of small droplets (100 micron) than the standard nozzle, but at the same time the Eurofoil has an energy that is so much higher than the standard nozzle, which means that drops from Eurofoil has a larger opportunity to reach the soil without drifting away.
- That Eurofoil produces a lower number of drops below 200 micron than the standard nozzle, but still has twice as much energy as the XR 110-04 flat fan nozzles.
- That the mean droplet size is almost 20 % larger than the mean droplet size from the standard nozzle.
- That the Eurofoil atomizer has a larger span of droplet sizes.
- That the Eurofoil atomizer has a higher velocity on the droplets.
Small droplets are effective, as they give a much better and much more uniform deposition on the leaves. Larger droplets are more alike to slide of the leaf after hitting it - if they hit at all. To achieve the most efficient spraying, and to avoid drift, it is important that the droplets are as many and as little as possible - with our Eurofoil atomizer this is possible - because the air pressure secures the required speed for the small droplets.
The Droplet spectrum
The droplet spectrum on the Eurofoil® atomizer has, on several occasions, been tested by Danish and foreign research institutions, including JKI from Germany. It has been tested using different air pressures and studies shows that the droplet spectrum depends entirely on air pressure and not by amount of liquid. This means that liquid consumption between 20-100 l/ha does not affect droplet spectrum - provided that air pressure is unchanged.
In the latest analysis, the droplet spectrum from two conventional nozzles was also analyzed (LH XR110-04 and DG 110-04). The result of the measurement of the droplet size, at a distance of 50 cm below the atomizer, showed that the share of droplets below 100 and 200 micron, in percentage, were higher than the measurements from the compared conventional nozzles.
Here we must note that if it should be possible to use liquid and chemical saving techniques, this must be the result in order to ensure a sufficient coverage of the target. Spraying with a low amount of liquid and chemicals requires a certain number of droplets in order to be able to cover the target adequately. This number can only be estimated and is highly dependent on the current situation in the field. Factors such as spray target, density of crops and coverage, competition between crops and weeds, the need for crop protection treatments, type of pesticide, and weather conditions should be taken into account in the planning prior to the start of each spraying.
Eurofoil® vs. conventional nozzles
When using conventional spray techniques, small and large droplet characteristics are perceived as follows:
These characteristics cannot be found readily when using danfoil’s field sprayers. When using a danfoil field sprayer the drops are added with energy, thus the unfortunate characteristics of the droplets are eliminated. These include factors such as wind sensitivity, nedtrængningsevne and bevægelsesenergi.
The danfoil concept – using the Eurofoil atomizer – eliminates not only the unfortunate characteristics of the droplet, but also combines the advantages of the small and large droplets.
In the following sketch the differences in sprøjtedoucher from conventional nozzles and from a Eurofoil® atomizer is showed.
Very small droplets can be difficult to manage. They linger in the air like a mist, which, in calm weather, will stretch like a long tail after the field sprayer. Even very little wind can lead such fine droplets astray. The drift is bigger over low and open crops than over high dense crops, which can grab hold of the droplets.
The danfoil field sprayer mix liquid and air in the atomizer. An airstream tear the spray liquid into small droplets and carries them down into the crop. The airflow, that determines the droplet size, can be varied. Thanks to the droplets high speed, the drift is reduced and the crops are hit more accurately.
Very small droplets can be difficult to manage. They linger in the air like mist, which, in calm weather, will strech like a ling tail after the field sprayer. Even very little wind can lead such fine droplets astray.
Drift is greater over low, open crops than over high, dense crops, which can better grab hold of the droplets.
The danfoil field sprayer mix liquid and air in the atomizer. An air stream tears the spray liquid into tiny droplets and carries them down into the crop. The airflow, which determines the droplet size, can be adjusted.
Thanks to the high speed of the droplets, drift is reduced and the crops are hit more accurately.