Comparison%20of%20Drift%20Potential%20for%20Venturi,%20Extended%20Range,%20and%20Turbo%20Flat-fan%20Nozzles

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Comparison of Drift Potential for Venturi,
Extended Range, and Turbo Flat-fan Nozzles

• Robert Wolf
• Biological and Agricultural Engineering Dept.
• Cathy Minihan
• Department of Agronomy

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Nozzle is still an important part of the
application process!

• Determines the application rate
• Determines the uniformity
• Determines the coverage
• Determines the drift potential

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Will determine coverage

• Need knowledge of the product being used.
• Systemic
• Contact
• What is the target?
• Soil
• Grass
• Broadleaf (smooth, hairy, waxy)
• Leaf orientation time of day

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Will affect drift

• Movement of spray particles off-target.
• Creating smaller spray drops will result in
  increased drift.
• Is it Coverage vs Drift?
• What is the answer?

64,000 Question?
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Efficacy and Drift Potential is Influenced by

• Size of the Spray Droplets -
• Volume Median Diameter (VMD)
• Droplet Spectrum (Range - big to small)

Volume or Number of droplets less than 200
microns in size
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Nozzle Technology Today?

• Nozzles designed to reduce drift
• Improved drop size control
• Emphasis on Spray Quality

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Extended Range Flat-fan

• Tapered edge pattern
• 80 and 110 degree fan
• Requires overlap - 50 to 60
• 15-60 psi range

80
110
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Turbo Flat-fan

• Turbulence chamber as in the Turbo Flood
• Tapered edge, wide angle flat pattern
• Designed to work in flat-fan nozzle holder
• Uniform spray distribution, 50-60 overlap
• Wide pressure range, 15 90 psi
• Large, drift resistant droplets
• Plastic with superior wear characteristics

TT
XR
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Air/Induction Venturi Nozzle

• Greenleaf TurboDrop
• Air intake venturi section
• Mixing Chamber - air and spray solution blended
• Pattern tip forms large air-bubble drops
• Required Exit tip flow 2X venturi orifice
• Better Penetration?
• Reduced run-off?
• Improved coverage?
• Adequate efficacy?
• Reduced drift?

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XR Flat-fan and Turbo Flat-fan compared to
Venturi Style Nozzle5.0 MPH wind at 40 psi
XR vs TurboDrop
Turbo Flat vs Turbo Drop
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1/2 of spray volume smaller droplets
VMD
1/2 of spray volume larger droplets
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Objective of this study

• Field measure the spray droplet characteristics
  to evaluate the drift potential of a venturi
  flat-fan nozzle compared to extended range and
  turbo flat-fan nozzles.

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Materials and Methods

• Experiments Exp. 1 and 2 Early and Late
  Postemergence Grass
• Exp. 3 and 4 Early and Late Postemergence
  Broadleaves
• Location Manhattan, KS
• Exp. Design 2 x 3 x 3 factorial with 4 reps
• Plot Size 3 x 9 m with 1.5 m buffer
• Crop Oats Don(Exp. 1 and 2)
• Weeds Velvetleaf, pigweed, and morning glory
  (Exp. 3 and 4)
• Visual Ratings 1, 2, and 4 weeks after treatment
• Herbicides (2) Paraquat, 0.14 kg/ha
• Glyphosate, 0.23 kg/ha
• Application Conditions
• Exp. 1 Exp. 2 Exp. 3 Exp. 4
• Date April 19, 2000 May 5, 2000 Aug. 18,
  2000 Sept. 1, 2000
• Oat/weed Size 15 cm 51 cm 10 cm 21 cm
• Temperature 20 C 25 C 21 C 24C
• R. H. 50 56 75 71

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Materials and Methods cont.

• Spray Tips (3) Extended Range Flat-fan (XR)
• Turbo Flat-fan (TT)
• Air Induction Flat-fan (AI)
• Spray Volumes (3) 47 L/ha (110015 orifice tips)
• 94 L/ha (11003 orifice tips)
• 187 L/ha (11006 orifice tips)
• Application Ground Speed 10 km/h
• Spray Pressure 276 kPa
• Spray Tip Spacing 76 cm
• Canopy Boom Height 51 cm

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DropletScan? used to analyze droplets
Water Sensitive Paper
Software lock-key
Color Scanner
Portable computer
Color Printer
System Components
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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.

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Important Droplet Statistics

• Dv0.1 (µm) - 10 of the spray volume in drops lt
  number reported
• Dv0.5 (µm) - 50 of the spray volume in drops lt
  number reported
• (also is VMD- volume median diameter)
• Dv0.9 (µm) - 90 of the spray volume in drops lt
  number reported
• Number of droplets under 200 microns

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Important Droplet Statistics
VMD (50)
Operational Area
VD0.9 (90)
VD0.1 (10)
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Collection Procedure
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Sample cards
TT
XR
AI
10 GPA
XR
TT
AI
5 GPA
TT
XR
AI
20 GPA
All at 40 PSI
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Results and Discussion
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All Treatments Number of Droplets lt 200 Microns
5 GPA
20 GPA
10 GPA
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Orifice Size Affect Number of Droplets lt 200
Microns
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Summary of Findings - Droplet Count under 200
microns

• At 47 L/ha the extended range flat-fans nearly
  doubled the turbo flat-fans and created more than
  four times the venturi flat-fans number of
  droplets less than 200 microns in size.
• At 94 L/ha the extended range flat-fans again
  nearly doubled the turbo flat-fans and more than
  tripled the venturi flat-fans for number of
  droplets created under 200 microns.

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Summary of Findings - Droplet Count under 200
microns

• At 187 L/ha the differences showed similar trends
  but were not nearly as pronounced.
• Increasing the application volumes for each
  nozzle type by increasing the nozzle orifice size
  also reduced the number of driftable droplets.
• Venturi nozzle designs reduce the number of
  droplets created under 200 microns in size when
  compared to extended range and turbo flat-fan
  nozzle styles.

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XR Flat-fan and Turbo Flat-fan compared to
Venturi Style Nozzle5.0 MPH wind at 40 psi
XR vs TurboDrop
Turbo Flat vs Turbo Drop
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Thanks