Developing the USDA ARS Spray Nozzle Models for Rotary Wing Applications

2017 ◽  
Vol 33 (5) ◽  
pp. 631-640
Author(s):  
W Clint Hoffmann ◽  
Bradley K Fritz
Keyword(s):  
Droplet Size ◽  
User Interfaces ◽  
Computational Models ◽  
Spray Deposition ◽  
Orientation Angle ◽  
Spray Drift ◽  
Product Label ◽  
Aerial Application ◽  
Nozzle Orifice ◽  
Rotary Wing

Abstract. Optimizing aerial spray applications requires proper setup of the sprayer system, particularly with respect to nozzle selection and operation, which significantly affects spray deposition, product efficacy, and spray drift. Droplet size from an aerial application is a function of the combination of nozzle type, nozzle orifice size, spray pressure, orientation angle, and airspeed of the aircraft. A set of computational models for 14 commonly-used aerial application nozzles were developed and released for use by applicators. These models allow applicators to determine the droplet size characteristics associated with their specific nozzle and operational setup, determining the proper combination of orifice, pressure, orientation, and airspeeds from 22 to 54 m/s (50 to 120 mph), which are commonly-associated with applications made from rotary wing aircraft (i.e., helicopters). Both spreadsheet and smartphone user interfaces are available for applicators to use to ensure that their application conforms to the legal droplet size requirements specified on an agrochemical product label. Keywords: Aerial application, Atomization, Droplet size, Droplet size models, Spray nozzles.

scholarly journals Model based decision support system of operating settings for MMAT nozzles

2016 ◽  
Vol 56 (2) ◽  
pp. 178-185 ◽  
Author(s):  
Bradley Keith Fritz ◽  
Zbigniew Czaczyk ◽  
Wesley Clint Hoffmann
Keyword(s):  
Decision Support ◽  
Experimental Design ◽  
Decision Support System ◽  
Droplet Size ◽  
Flow Rate ◽  
Support System ◽  
Computational Models ◽  
Ease Of Use ◽  
Size Spectrum ◽  
Orifice Size

Abstract Droplet size, which is affected by nozzle type, nozzle setups and operation, and spray solution, is one of the most critical factors influencing spray performance, environment pollution, food safety, and must be considered as part of any application scenario. Characterizing spray nozzles can be a timely and expensive proposition if the entire operational space (all combinations of spray pressure and orifice size, what influence flow rate) is to be evaluated. This research proposes a structured, experimental design that allows for the development of computational models for droplet size based on any combination of a nozzle’s potential operational settings. The developed droplet size determination model can be used as Decision Support System (DSS) for precise selection of sprayer working parameters to adapt to local field scenarios. Five nozzle types (designs) were evaluated across their complete range of orifice size (flow rate*) and spray pressures using a response surface experimental design. Several of the models showed high level fits of the modeled to the measured data while several did not as a result of the lack of significant effect from either orifice size (flow rate*) or spray pressure. The computational models were integrated into a spreadsheet based user interface for ease of use. The proposed experimental design provides for efficient nozzle evaluations and development of computational models that allow for the determination of droplet size spectrum and spraying classification for any combination of a given nozzle’s operating settings. The proposed DSS will allow for the ready assessment and modification of a sprayers performance based on the operational settings, to ensure the application is made following recommendations in plant protection products (PPP) labels.

scholarly journals Development of Drift-Reducing Spouts For Vineyard Pneumatic Sprayers: Measurement of Droplet Size Spectra Generated and Their Classification

2020 ◽  
Vol 10 (21) ◽  
pp. 7826
Author(s):  
Marco Grella ◽  
Antonio Miranda-Fuentes ◽  
Paolo Marucco ◽  
Paolo Balsari ◽  
Fabrizio Gioelli
Keyword(s):  
Droplet Size ◽  
Marked Reduction ◽  
Reduction Potential ◽  
Liquid Flow Rate ◽  
Spray Drift ◽  
Spray Application ◽  
Size Spectra ◽  
Wide Range ◽  
Environmental Requirements ◽  
Low Drift

Pneumatic spraying is especially sensitive to spray drift due to the production of small droplets that can be easily blown away from the treated field by the wind. Two prototypes of environmentally friendly pneumatic spouts were developed. The present work aims to check the effect of the spout modifications on the spray quality, to test the convenience of setting the liquid hose out of the spout in cannon-type and hand-type pneumatic nozzles and its effect on the droplet size, homogeneity and driftability in laboratory conditions. Laboratory trials simulating a real sprayer were conducted to test the influence of the hose insertion position (HP), including conventional (CP), alternative (AP), outer (OP) and extreme (XP), as well as the liquid flow rate (LFR) and the airflow speed (AS) on the droplet size (D50, D10 and D90), homogeneity and driftability (V100). Concurrently, the droplet size spectra obtained by the combination of aforementioned parameters (HP × LFR × AS) in both nozzles were also classified according to the ASABE S572.1. Results showed a marked reduction of AS outside the air spout, which led to droplet size increase. This hypothesis was confirmed by the droplet size spectra measured (D50, D10, D90 and V100). A clear influence of HP was found on every dependent variable, including those related with the droplet size. In both nozzles, the longer the distance to CP, the coarser the sprayed drops. Moreover, LFR and AS significantly increased and reduced droplet size, respectively. A higher heterogeneity in the generated drops was obtained in XP. This position yielded V100 values similar to those of the hydraulic low-drift nozzles, showing an effective drift reduction potential. The classification underlines that the variation of HP, alongside AS and LFR, allowed varying the spray quality from very fine to coarse/very coarse, providing farmers with a wide range of options to match the drift-reducing environmental requirements and the treatment specifications for every spray application.

scholarly journals Spray Deposition on Weeds (Palmer Amaranth and Morningglory) from a Remotely Piloted Aerial Application System and Backpack Sprayer

Drones ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 59
Author(s):  
Daniel Martin ◽  
Vijay Singh ◽  
Mohamed A. Latheef ◽  
Muthukumar Bagavathiannan
Keyword(s):  
Spray Deposition ◽  
Tap Water ◽  
Application Rate ◽  
Palmer Amaranth ◽  
Test Results ◽  
Herbicide Application ◽  
Aerial Application ◽  
Spray Droplet ◽  
Application System ◽  
Leaf Surfaces

This study was designed to determine whether a remotely piloted aerial application system (RPAAS) could be used in lieu of a backpack sprayer for post-emergence herbicide application. Consequent to this objective, a spray mixture of tap water and fluorescent dye was applied on Palmer amaranth and ivyleaf morningglory using an RPAAS at 18.7 and 37.4 L·ha−1 and a CO2-pressurized backpack sprayer at a 140 L·ha−1 spray application rate. Spray efficiency (the proportion of applied spray collected on an artificial sampler) for the RPAAS treatments was comparable to that for the backpack sprayer. Fluorescent spray droplet density was significantly higher on the adaxial surface for the backpack sprayer treatment than that for the RPAAS platforms. The percent of spray droplets on the abaxial surface for the RPAAS aircraft at 37.4 L·ha−1 was 4-fold greater than that for the backpack sprayer at 140 L·ha−1. The increased spray deposition on the abaxial leaf surfaces was likely caused by rotor downwash and wind turbulence generated by the RPAAS which caused leaf fluttering. This improved spray deposition may help increase the efficacy of contact herbicides. Test results indicated that RPAASs may be used for herbicide application in lieu of conventional backpack sprayers.

Fading Activities of Herbicidal Droplets Amended with Emulsifiable Spray Adjuvants on Cucurbitaceous Leaves

2018 ◽  
Vol 61 (6) ◽  
pp. 1881-1888
Author(s):  
Jeng-Liang Lin ◽  
Heping Zhu
Keyword(s):  
Weed Control ◽  
Droplet Size ◽  
Spray Deposition ◽  
Herbicide Application ◽  
Spray Droplet ◽  
Coverage Area ◽  
Maximum Coverage ◽  
Fading Time ◽  
Selection Of ◽  
Spray Adjuvants

Abstract. Understanding reactions of surfactant-amended droplets on difficult-to-wet weed surfaces could help develop application strategies to increase herbicide efficacy. Behaviors of herbicidal droplets containing different emulsifiable anti-evaporation spray adjuvants were investigated by characterizing 250 and 450 µm herbicidal droplet dispersion and fading time on cucurbitaceous leaves placed inside a 20°C chamber at 30% and 60% relative humidity (RH). Droplet maximum coverage area increased with droplet size but not with RH, while droplet fading time increased with both droplet size and RH. Despite 450 µm droplets having greater maximum coverage area than 250 µm droplets, the larger droplets had higher fading rates and lower ratios of maximum coverage area to droplet volume. Droplet maximum coverage area and fading time on leaves were affected by adding spray adjuvants to the herbicide-only solution. The Uptake surfactant was more effective than the other two surfactants (AntiEvap+BS1000 and Enhance) in increasing droplet maximum coverage area and fading time. Compared to the herbicide-only solution, addition of Uptake surfactant to the herbicide solution could increase maximum coverage area by 68% and 52% for 250 and 450 µm droplets, respectively, but addition of AntiEvap+BS1000 or Enhance surfactants did not show significant increase. Similarly, addition of Uptake surfactant to the herbicide-only solution increased droplet fading times by 11.1% and 13.2% at 30% and 60% RH, respectively, for 250 µm droplets and by 34.7% and 2.8% at 30% and 60% RH, respectively, for 450 µm droplets. In contrast, addition of AntiEvap+BS1000 surfactant reduced fading time, and addition of Enhance surfactant did not significantly affect fading time. Therefore, appropriate selection of spray adjuvants for herbicide applications could significantly influence droplet deposit behaviors on cucurbitaceous leaves, leading to improved effectiveness of weed control. Keywords: Herbicide application, Spray deposition, Spray droplet, Surfactant, Weed control.

Herbicide Formulation, Spray Nozzle Design, and Operating Pressure Affects the Droplet Size Spectra of Agricultural Sprays

2019 ◽  
pp. 1-7 ◽  
Author(s):  
Joshua A. McGinty ◽  
Gaylon D. Morgan ◽  
Peter A. Dotray ◽  
Paul A. Baumann
Keyword(s):  
Wind Tunnel ◽  
Droplet Size ◽  
The United States ◽  
Spray Drift ◽  
Operating Pressure ◽  
Spray Nozzle ◽  
Spray Droplet ◽  
Size Spectra ◽  
Drift Potential ◽  
Spray Droplets

Aims: Determine the droplet size spectra of agricultural sprays as affected by herbicide formulations, spray nozzle designs, and operating pressures. Place and Duration of Study: This study was conducted in April 2014 at the United States Department of Agriculture Agricultural Research Service Aerial Application Technology Research Unit Facility in College Station, Texas. Methodology: The spray droplet size spectra of six herbicide formulations as well as water alone and water with nonionic surfactant were evaluated in a low-speed wind tunnel. These spray solutions were conducted with five different flat-fan spray nozzle designs, producing a wide range of spray droplet sizes. The wind tunnel was equipped with a laser diffraction sensor to analyze spray droplet size. All combinations of spray solution and nozzle were operated at 207 and 414 kPa and replicated three times. Results: Many differences in droplet size spectra were detected among the spray solutions, nozzle designs, and pressures tested. Solutions of Liberty 280 SL exhibited the smallest median droplet size and the greatest proportion of spray volume contained in droplets 100 µm or less in size.  Solutions of Enlist Duo resulted in smaller median droplet size than many of the solutions tested, but also exhibited some of the smallest production of fine spray droplets. Median droplet size was found to vary greatly among nozzle designs, with the greatest droplet size and smallest drift-prone fine droplet production observed with air-inclusion designs utilizing a pre-orifice. Increasing the operating pressure from 207 to 414 kPa resulted in a decrease in median droplet size and an increase in the production of droplets 100 µm or less in size. Conclusion: Herbicide formulations and spray nozzle designs tested varied widely in droplet size spectra and thus the potential for spray drift. Increasing operating pressure resulted in decreased droplet size and an increase in the production of drift-prone droplets. Additionally, median droplet size alone should not be used to compare spray drift potential among spray solutions but should include relative span and V100 values to better predict the potential for spray drift due to drift-prone spray droplets.

Field Scale Evaluation of Spray Drift Reduction Technologies from Ground and Aerial Application Systems

2011 ◽  
Vol 8 (5) ◽  
pp. 103457 ◽  
Author(s):  
Bradley K. Fritz ◽  
W. Clint Hoffmann ◽  
W. E. Bagley ◽  
Andrew Hewitt ◽  
B. Devisetty ◽  
...  
Keyword(s):  
Spray Drift ◽  
Field Scale ◽  
Aerial Application ◽  
Scale Evaluation ◽  
Application Systems

The Washington aerial spray drift study: Modeling pesticide spray drift deposition from an aerial application

2005 ◽  
Vol 39 (33) ◽  
pp. 6194-6203 ◽  
Author(s):  
M TSAI ◽  
K ELGETHUN ◽  
J RAMAPRASAD ◽  
M YOST ◽  
A FELSOT ◽  
...  
Keyword(s):  
Spray Drift ◽  
Aerial Application

scholarly journals Meeting droplet size specifications for aerial herbicide application to control wilding conifers

2020 ◽  
Vol 73 ◽  
pp. 13-23
Author(s):  
Brian Richardson ◽  
Carol Rolando ◽  
Andrew Hewitt ◽  
Mark Kimberley
Keyword(s):  
Droplet Size ◽  
Field Performance ◽  
The Other ◽  
Spray Drift ◽  
Spray Application ◽  
Herbicide Application ◽  
Water Control ◽  
Drift Potential ◽  
Droplet Sizes ◽  
Air Speed

Large areas of New Zealand are being aerially sprayed with herbicides to manage ‘wilding’ conifer spread. The purpose of the study was to obtain and analyse droplet spectra produced by nozzles commonly used for wilding conifer spraying to determine whether or not operational recommendations for a target droplet size class (~350 µm) are being met. Droplet spectra were measured in a wind tunnel for 27 nozzle x 3 operating condition (nozzle angle, air speed and pressure) combinations tested for each of three spray mixes. AGDISP, an aerial spray application simulation model, was used to quantify the field performance implications of changes to droplet spectra parameters. Only one nozzle, the CP-09, 0.078, 30°, met the target droplet size specification when used at 45° but not at 0°. However, under these conditions, this nozzle produced a large driftable fraction. All but one of the other scenarios tested produced much larger droplet sizes. Operational spray mixes tended to slightly increase the potential for spray drift compared with the water control. The CP-09, 0.078, 30° nozzle used at 45° met the operational droplet size specification but is more sensitive to changes to nozzle angle (0° versus 45°) than the other nozzles tested. None of the three Accu-FloTM nozzles tested met the target droplet size specification. However, the Accu-FloTM nozzles produced very few fine droplets making them good choices for reducing spray drift potential.

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