Effects of Air Speed and Liquid Temperature on Droplet Size

    Volume 8, Issue 4 (April 2011)

    ISSN: 1546-962X

    CODEN: JAIOAD

    Published Online: 25 April 2011

    Page Count: 9


    Hoffmann, W. Clint
    USDA-ARS, College Station, TX

    Fritz, Bradley K.
    USDA-ARS, College Station, TX

    Bagley, W. E.
    Wilbur-Ellis Company, San Antonio, TX

    Lan, Yubin
    USDA-ARS, College Station, TX

    (Received 5 October 2010; accepted 10 March 2011)

    Abstract

    Advancements in both application hardware (e.g., nozzles and spray assist devices) and spray property modification products have led to a number of products that are specifically designed to maximize the on-target deposition and minimize off-target movement of spray droplets. Testing protocols are being developed to objectively measure spray drift reduction from a wide range of drift reduction technologies (DRTs) including spray nozzles, sprayer modifications, spray delivery assistance, spray property modifiers (adjuvants), and/or landscape modifications. Using a DRT evaluation protocol, the objectives of this work were to study the effects of different air speeds on droplet size from different spray nozzles and spray solutions and to further evaluate the effects of differences in liquid and air temperature on droplet size at the different air speeds tested. Measured spray droplet size was significantly affected by changes in airspeed with the DV0.5 increasing by ∼30–100 μm and the percent of spray volume less than 200 μm decreasing by 50 % or more as the tunnel airspeed was increased from 0.5 to 6.7 m/s (1 to 15 miles per hour), depending on the spray solution, spray nozzle, and air speed. The data also showed a lesser influence of temperature differential between the spray solution and ambient air, with the differences seen most likely resulting from changes in spray solution physical properties with the changes in liquid temperature. Most importantly, this study demonstrated that a reference nozzle evaluated under the same conditions resulted in the reduction in driftable fines while the DRT remained constant across all conditions tested.


    Paper ID: JAI103461

    DOI: 10.1520/JAI103461

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    Author
    Title Effects of Air Speed and Liquid Temperature on Droplet Size
    Symposium 31th Symposium on Pesticide Formulations and Delivery Systems: Innovative Green Chemistries for the 21st Century, 2010-10-12
    Committee E35