Comparison of Drift for Four Drift-Reducing Flat-fan Nozzle Types Measured in a Wind Tunnel and Evaluated using DropletScan Software
Results of Position 1 and 2 Card Data:
Robert E. Wolf & Daniel D. Frohberg, Kansas State University, Manhattan, KS
This study was to compare, in a wind tunnel, the amount of drift from venturi, Combo-Jet, extended range, and turbo flat-fan nozzles at the recommended operating pressure for each.
Four drift-reducing flat-fan nozzles were compared for drift volume at 47 and 94 L/ha, parallel to a 4.6 m/s wind speed, and at their common recommended field operating psi.
- The mean for drift on the card in position 1 for the XR at 47 L/ha (28.78) reflects a significantly greater drift amount than for the TT, DR and AI tips (8.85, 1.28, 1.45).
- The TT also had significantly more drift when compared to the DR and AI.
- No significance was found between the DR and AI.
- At 94 L/ha, the XR created more drift than the TT, but was not significantly different (13.2, 8.85).
- Both developed significantly more drift than the DR and AI (2.03, 1.53).
- The DR and AI were not significantly different in the amount of drift created.
- Similar trends are shown at the second card location.
- For the XR flat-fan tip at both card locations, increasing the application volume from 47 to 94 L/ha significantly reduced the amount of drift created.
- For all the other nozzle treatments, no significance was found as the application volumes increased.
- Summed across all tips and cards, there was a significant reduction in drift as the application volume was increased. However, the data would reflect that the XR was responsible for the difference.
- The extended range (XR) created significantly more drift than the turbo flat-fan (TT), Combo-Jet flat-fan (DR), and venturi flat-fan (AI).
- The TT was significantly better for reducing drift than the XR at 47 L/ha, but not at 94 L/ha.
- The DR and AI were not significantly different from each other.
- For the XR, increasing the application volume from 47 to 94 L/ha significantly reduced the amount of drift.
- This finding did not hold true for the TT, DR, and AI flat-fans.
- The use of drift reducing nozzle designs significantly reduces drift.
A wind tunnel was used to compare drift amounts from venturi, (AI); extended range, (XR); turbo, (TT); and Combo-Jet, (DR) flat-fan spray tips. The AI, XR, and TT are Spraying Systems tips and the DR tip is from Wilger.
- Tips were compared at 47 and 94 L/ha.
- Spray pressures used were 173 kPa, XR; 242 kPa, TT and DR, and 345 kPa, AI.
- The nozzle angle and orifice sizes used were: 110015 and 11003 for the XR and TT, 110015 and 110025 for the AI, 80015 and 8003for the DR.
- The 015 and 025/03 orifice sizes respectively determined the 47 and 94 L/ha application volumes.
- Applications using water and a single nozzle boom were made.
- A wind speed of 4.6 m/s was maintained.
- Each nozzle treatment was positioned parallel to the wind and located from 45.7 to 50.8 cm above the target.
- A 25 cm high canopy was placed on the wind tunnel floor.
- Single water sensitive cards were placed 2, 3, and 4 meters downwind from the tip to collect the drifting droplets.
- Four reps per treatment were analyzed.
- DropletScan software was used to analyze the cards and determine percent area coverage – drift amount.
- ANOVA was used to test for equality of means.
Controlling or minimizing the off-target movement of sprayed crop protection products is critical. Nozzle manufactures are designing nozzles that will effectively reduce the volume of driftable fines found in the spray droplet spectra. A recent trend is to incorporate a ‘venturi’ that includes the spray droplet in air to lessen the drift potential. More information about how to use the latest nozzle technologies to maximize efficacy while minimizing the drift potential is important.
- The recommended pressure, the four tips compared produced significantly different amounts of drift.
- The drift reducing nozzle designs do not show drift reductions when increasing the application volume.
- Nozzles designed to reduce drift will significantly reduce the amount of drift when compared to XR flat-fans.