Comparison of Off-Target Deposits for Conventional Spray Nozzles and Venturi Nozzles

1. Comparison of Off-Target Deposits for Conventional Spray Nozzles and Venturi Nozzles Robert Wolf Biological and Agricultural Engineering Dept. Dallas Peterson and Cathy Minihan Department of Agronomy

2. New Technology for the Spray Industry

3. Nozzle is still an important part of the application process! • Determines the application rate • Determines the uniformity • Determines the coverage • Determines the drift potential

4. What’s new in nozzle technology? • Nozzles designed to reduce drift • Improved drop size control

5. Air-Induction/Venturi Nozzles Where air is drawn into the nozzle cavity and exits with the fluid.

6. Example Design -TurboDrop • Dual Air inlet/venturi • Mixing Chamber - air and spray solution blended • Pattern contains large air-bubble drops • Better Penetration???? • Reduced run-off????? • Improved coverage?????

7. 1/2 of spray volume = smaller droplets VMD 1/2 of spray volume = larger droplets

8. Match the crop protection product to the target Adhere to label guidelines based on an industry standard ASAE X-572 Maximize Efficacy and Minimize drift What to Expect in the Future? VMD

10. Objectives of this study: • Compare drift characteristics of conventional vs. air induction -venturi style nozzles • Determine if the DropletScan software will provide quick and useful information regarding drift for various nozzle types.

11. What is DropletScan ? • A software program that will allow accurate and rapid measure of spray droplet impressions on water-sensitive paper. • Developed at K-State by Devore Systems - modeled after ‘Crumbscan’, a software program to determine hole sizes in slices of bread. • Marketed by WRK for specific use in aerial applications spray analysis concentrating on spray droplet characterization.

12. DropletScan is Field Ready & Simple! Water Sensitive Paper Software & lock-key Color Scanner Portable computer Color Printer System Components

13. Procedures Involved: • Use the spot cards during spray run to collect spray that travels out of target area • horizontal and vertical • Scan cards and analyze by software • Droplet stains are measured • Spread factors are used for material sprayed • Equivalent droplet diameter is calculated • % target area being covered • application rate

14. Acquiring an image from water sensitive paper or other color contrasting material. 2-step process Low resolution High resolution Select report options Basic system processes:

15. SamplePrintout

16. SamplePrintout

17. Sample Printout

18. TD @ 40 XR @ 40

19. XR @ 40 TD @ 40

20. Spray Characteristics are Important to Understand: Click on spray to see video Demonstrates Turbo Flat vs TurboDrop-5 MPH Wind

21. Drop Data Descriptions: • Dv0.1 (µm) - 10% of the spray volume in drops < number reported • Dv0.5 (µm) - 50% of the spray volume in drops < number reported (also is VMD- volume median diameter) • Dv0.9 (µm) - 90% of the spray volume in drops < number reported

22. Study With 3-Parts involving Air Induction Venturi Nozzles and Droplet Scan Analysis: • Comparing On Target(under the boom) Droplet Characteristics – Reported at 1999 ASAE Summer Meeting – paper # 991026. • Field Efficacy/Drift Study – Reported in Successful Farming Magazine, Nov. 99 vol. 97, #12 pp. 46-8. • Drift Comparison Analysis – NCWSS ‘99

23. 3 conventional nozzles 4 air-induction/venturi 138, 276, 551 kPa 76 L/A, 76cm, 51cm Materials and Methods for all 3 parts:

24. Part #1 - Sample of an under boom collection: • Passed sprayer over a collector board with five equally spaced water-sensitve cards attached. • 5 cards were collected for each of the 7 nozzles at each pressure.

25. Part #2 -Air-Induction/Venturi Nozzle Efficacy Study May 1999

26. Part #2 – Plot Layout • 3reps, 7 nozzles, 3 psi’s • 20GPA, Gromoxone, 10’ boom • 5’ buffer

27. Part #3 – Drift Collector Study: 4 ft. 3 ft. 10 ft. 9 ft. 8 ft. Card Holder 4 ft. 2 ft. 1 ft. 8 ft. Tower Vertical Collector Horizontal Collector Center Line of Spray Wind direction

28. Example of a collection: • Sprayed past a collector board and tower with six equally spaced water-sensitve cards attached. • 3 cards were collected horizontal and 3 cards were collected vertical for each nozzle at 138, 276, and 551 kPa pressure. • 2 passes per collection Horizontal Vertical

29. XR Flat-fan @138-276-551 kPa Turbodrop XL @138-276-551 kPa

30. Results and Discussion

31. Findings for Part #3: • DropletScan does appear to be a software program that will provide quick and useful information regarding drift for various nozzle types. • Data supports that drift potential is less with the venturi nozzles compared to the conventional nozzles. • The collection technique needs to be fine-tuned to make better use of the data collection possibilities.

32. Important to note that: • May be advantages to analyzing the spray droplet at the target site rather than as it leaves the spray tip. • Will measure stains as small as 50 microns. • Good analysis of lower application rates and driftable size fines.

33. Important to note that: • Humid/moist conditions currently will not allow system to be effective. • Even though the wind confused the data in this study, wind does have a major affect on deposition and drift and must be factored in for each application scenario.

34. Thanks