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

Kansas State University Biological and Agricultural Engineering Department

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


Nozzle is still an important part of the application process!

Determines the application rate

Determines the uniformity Determines the coverage Determines the drift potential


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


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?


Efficacy and Drift Potential is Influenced by:Efficacy and Drift Potential is Influenced by:

Size of the Spray Droplets -Volume Median Diameter (VMD)

Droplet Spectrum (Range - big to small)

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

% Volume or Number of droplets less than 200 microns in size


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

Nozzle Technology Today?


Extended Range Flat-fan: Tapered edge pattern 80 and 110 degree fan Requires overlap - 50 to 60% 15-60 psi range

110°

80°


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

XR

TT


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?


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


1/2 of spray volume = larger droplets1/2 of spray volume = larger droplets

VMDVMD

1/2 of spray volume = smaller droplets1/2 of spray volume = smaller droplets


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.


Materials and Methods:Experiments: Exp. 1 and 2 Early and Late Postemergence Grass

Exp. 3 and 4 Early and Late Postemergence Broadleaves

Location: Manhattan, KSExp. Design: 2 x 3 x 3 factorial with 4 repsPlot Size: 3 x 9 m with 1.5 m bufferCrop 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/haGlyphosate, 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% Wind: W-NW 8-10 km/h SE 5-8 km/h NE 11-19 km/h N-E 3-10 km/h


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/hSpray Pressure: 276 kPaSpray Tip Spacing: 76 cmCanopy Boom Height: 51 cm


DropletScan used to analyze droplets:

System ComponentsSystem Components


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.


Important Droplet Statistics:

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

Number of droplets under 200 microns


Important Droplet Statistics:

Operational Area


Collection Procedure:


XR AITT

TT

TTXR

XR

AI

AISample cards:

5 GPA

10 GPA

20 GPAAll at 40 PSI


Results and Discussion


All Treatments – Number of Droplets < 200 Microns

0

500

1000

1500

2000

2500

3000

Num

ber

of

Dro

plet

s < 2

00 M

icro

ns

110015 11003 11006

XR TT AI

5 GPA 20 GPA10 GPA


Orifice Size Affect – Number of Droplets < 200 Microns

0

500

1000

1500

2000

2500

3000

Num

ber

of D

ropl

ets

< 2

00 M

icro

ns

XR TT AI

5 GPA- 015 10 GPA- 03 20 GPA- 06


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.


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.


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


Thanks

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

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