2002 ASAE/NAAA Technical Session Program
Silver Legacy Hotel and Casino
Reno, NV
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STATIC WEAR CHARACTERISTICS OF CP POLYPROPYLENE AERIAL NOZZLES
Paper
No. AA02-001
Authors:
Jim Ross and N.E. Schmidt
Contact:
Jim Ross, Entomology, Plant Pathology, and Weed Science Department, Box 30003,
MSC 3BE, Skeen Hall N141, Las Cruces, NM 88003
Summary: An experiment is in progress to identify the static wear characteristics of CP polypropylene aerial nozzles (CP-03). A test bench designed to simulate an aircraft liquid dispersal system was used to pump a 0.5 lb / gal suspension of hydrous aluminum silicate (water washed kaolin clay) and tap water. The kaolin clay suspension was used to simulate a wettable powder pesticide formulation. Three current production replicate nozzles atomized the mixture for intervals of 24 and 48 hours. Individual nozzles were labeled for identification. Each nozzle was configured with a 0.125-inch orifice and 30 degree deflector. Test bench pressure was maintained at 30 psi. Tank mix replacement intervals were calculated by the formula described in ASAE S471. At 0, 24, 48, 96, 144…n hour intervals, the 3 replicate nozzles and the test bench were flushed with clean water and the flow rate of water at 30 psi was measured for each nozzle. Each of the three replicate nozzles was then taken to the wind tunnel facility where the droplet spectra of water were measured using an airspeed of 120 mi/hr and 30 psi spray pressure. Spray droplet parameters Dv0.1, Dv0.5. Dv0.9, relative span, % volume<105 um diameter and % volume< 220 um diameter will be evaluated as a measure of spray quality.
New developments in rotary atomiser technology to improve drift control - results from wind tunnel tests and field studies
ASAE
Paper
No. AA02-002
Author:
John Clayton
Contact: : John Clayton, Micron Sprayers Ltd, Bromyard, Herefordshire, HR7 4HS, UK mailto:john.clayton@micron.co.uk
Summary: This presentation will discuss several factors influencing drift from aircraft, notably drop size, uniformity and, most importantly, aircraft speed. Data will be presented on the impact of airspeed on drop size and problems of drop shatter with larger drops. Reducing airspeed greatly improves drift control with all nozzle types. The influence of tank mixes on surface tension and impact on drift will be discusses. A model has been developed to predict drop shatter against size, airspeed and physical characteristics from different tank mixes for rotary atomisers and their impact on drop size in the wind tunnel. The presentation will then describe the development of the AU5000 LD rotary atomiser, present wind tunnel data and spray patterns as well as this years results from field tests in cotton, bananas, cereals and potatoes from Australia, Africa and Central America.
The Effect of Load and Air Temperature on Aerial Application Ground Speed
ASAE
Paper
No. AA02-003
Author: Lowrey Smith
Contact:
Lowrey Smith, USDA-ARS, PO Box
Summary:
Most aerial applicators will agree that a spray plane flies more slowly
when fully loaded than when empty with the same engine power and RPM settings.
However, the magnitude of this difference has not been well documented
and is affected by various environmental factors.
A study was performed to determine if the ground speed changes due to
load changes were sufficient to have a significant effect on the application
rate of granular materials. An Air
Tractor 402b (turbine-powered), equipped with a SATLOC swath guidance system and
an AutoCal Automatic Flow-Controller was used to collect the required data.
Data logs from the SATLOC system provided ground speed and spray-time
data and AutoCal data files provided flowrate data from each spray run.
Test protocols were developed to minimize effects of parameters other
than load on ground speed. The
plane was loaded with 275 gal of water for each test to simulate the approximate
weight of a fertilizer load. Results
indicated that ground speed increased as load decreased and that increased
air-temperature tended to magnify this change.
Spray Deposition and Drift from two “Medium” Nozzles
ASAE
Paper
No. AA02-004
Authors:
W. Clint Hoffmann and I.W. Kirk
Contact:
Clint Hoffmann, USDA-ARS, 2771 F&B Road, College Station, TX 77845
Summary:
Many crop protection and production materials are requiring specific
droplet sizes for application, such as “apply as a MEDIUM spray.”
Aerial applicators are utilizing computer models and printed materials to
comply with these labels. The
objective of this study was to explore and highlight the differences in
deposition and drift from two “medium” nozzles.
With an application rate of 28 L/ha (3 gal/acre), CP nozzles were
configured to produce a VMD of 272 µm and Spraying Systems D8 straight stream
nozzles were configured to produce a VMD of 413 µm.
Under the current ASAE spray classification scheme would both be
classified as Medium sprays; however, the spray volume contained in droplets
less than 200 µm was 23.4% and 8.7% for the CP and D8 nozzles, respectively.
The two nozzle configurations were evaluated by measuring deposition and
drift in a crosswind when applied with an Air Tractor 402B.
Incremental deposition samples were collected out to 100 m (330 ft) from
the flightline on horizontal Mylar cards. At
50 m (164 ft), two vertical towers were erected 10 m (33 ft) apart. Monofilament line was suspended at 1, 5, 7.5, and 10 m (3.3,
16.5, 24.6, and 33 ft) heights to serve as collectors of airborne droplets.
The deposition measured from the horizontal and vertical collectors from
the two nozzles was significantly different.
The results show that applicators must continue to use their professional
judgment when selecting the appropriate nozzles for each and every application.
Aerial application of herbicides using low drift nozzles and tank mixes
ASAE
Paper
No. AA02-005
Author: Hewitt, A.J.
Contact:
Andrew Hewitt, Stewart Agricultural Research Services, Inc., P.O. Box
509, Macon, MO 63552
Summary: Wind tunnel studies have been conducted using low drift nozzles (Accu-Flo, TVB, solid stream and others) with various tank mixes including surfactants and seed oils, to determine ways of minimizing the “fines” in a spray for a given VMD droplet size. This paper explains the results of these studies, in a context of effective drift management with rotary wing aircraft for herbicide application. The data are particularly applicable to forestry applications.
SPRAY DRIFT ESTIMATES FROM AERIAL SPRAY DROPLET SPECTRA
ASAE Paper No. AA02-006
Authors:
I.W. Kirk and W.C. Hoffmann
Contact:
I.W. Buddy Kirk, USDA-ARS, 2771 F&B Road, College Station, TX 77845
Summary: A field study was conducted to determine influences of boom length and spray droplet size on effective swath width and spray drift from Hiller 12-E and Bell OH-58 helicopters. Boom lengths of 75 and 100 percent of rotor diameter and droplet sizes of 400 µm (Medium spray with 2.5% of spray volume in droplets less than 100 µm diameter) and 1000 µm (Extremely Coarse spray with 0.5 % of spray volume in droplets less than 100 µm diameter) were used for treatment conditions. Results of the study will provide helicopter operators with operational guidelines for boom length and spray droplet size to optimize swath width and mitigate spray drift from helicopter applications of crop production and protection products.
Practical Field Demonstrations for Drift Mitigation
ASAE
Paper
No. AA02-007
Authors: Robert E. Wolf and Dennis R. Gardisser
Contact:
Robert E. Wolf, Biological and Agricultural Engineering, Kansas State
University, 229 Seaton Hall, Manhattan, KS 66506
Summary:
Off-target drift is a major source of application inefficiency.
With new nozzle configurations and higher pressure recommendations, and
with the continued development of drift reducing tank mix materials, applicators
seek to better facilitate making sound decisions regarding the addition of drift
control products into their tank mixes. This
presentation reports on the comparison of several popular/new drift control products
tested in a practical field demonstration.
The demonstration involves using a drift collection tower to compare
several nozzle configurations, shear orientations, and pressures with and
without a variety of drift control products.
The data collected in this study will be of the quantity and quality that
will be reportable and beneficial to the aerial application industry.
The drift tower is located 300 feet downwind from the application flight
line and is extendable to a height of 40 feet.
Water sensitive paper is placed at 5-foot increments up the tower.
Pilots will make simulated applications along the flight line.
Water sensitive cards will also be placed in 50-foot increments along the
ground leading away from the flight line to the tower.
Off-target deposits will then be collected horizontally and vertically.
DropletScan software will be used to analyze the water sensitive paper on
site. For this study, the percent
coverage, the spray deposition rate (GPA), and drift profile, can all be easily
determined. Droplet statistics such
as VMD (V(0.5), Volume Median Diameter), V(0.1), and V(0.9)
are automatically calculated for each drop card scanned.
A printout with a histogram of the drop sizes (by droplet number and
percent of spray volume in each category) along with a graphic record of the
spot cards are provided by the software. This
will allow for adjustments in the application parameters and the opportunity to
make several more comparisons as pilots’ request.
For information on the American Society of Agricultural Engineers, click below:
For information on the National Agricultural Aviation Association, click below:
