Kansas State University Biological and Agricultural Engineering Department Comparison of Off-Target...

Kansas State University Biological and Agricultural Engineering Department

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


New Technology for the Spray Industry


Nozzle is still an important part of the application process!

Determines the application rate

Determines the uniformity Determines the coverage Determines the drift potential


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


Air-Induction/Venturi NozzlesWhere air is drawn into the nozzle

cavity and exits with the fluid.


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?????


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


What to Expect in the Future?

Example Reference Graph

Cumulative Volume Fraction

0.1 0.5 0.9

Dro

p S

ize

(mic

rons

)

0

100

200

300

400

500

600

700

800

900

very fine/ fine fine/mediummedium/ coarsecoarse/ very coarsevery coarse/ extremely coarse

VF

F

M

CVC

XC

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



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.


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.


DropletScan is Field Ready & Simple!

System ComponentsSystem Components


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


Basic system processes:

Acquiring an image from water sensitive paper or other color contrasting material.

2-step process– Low resolution– High resolution

Select report options


Sample Printout


Sample Printout


Sample Printout




Spray Characteristics are Important to Understand:

Click on spray to see video

Demonstrates Turbo Flat vs TurboDrop-5 MPH Wind


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


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


Materials and Methods for all 3 parts:

3 conventional nozzles 4 air-induction/venturi 138, 276, 551 kPa 76 L/A, 76cm, 51cm


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.


Part #2 -Air-Induction/Venturi

Nozzle Efficacy Study May 1999


Part #2 – Plot Layout

3 reps, 7 nozzles, 3 psi’s

20 GPA, Gromoxone, 10’ boom

5’ buffer


Part #3 – Drift Collector Study:

2 ft.

Center Line of SprayTower Vertical

Collector

Horizontal Collector

8 ft.

3 ft.

4 ft.

9 ft.10 ft.

1 ft.

Card Holder

8 ft.

4 ft.

Wind direction


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


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


Results and Discussion


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.


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.

Important to note that:


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.


Thanks

Date post:	05-Jan-2016
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Kansas State University Biological and Agricultural Engineering Department Comparison of Off-Target...

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