Droplet Characteristics and Near Nozzle Dispersion of Cold and Thermal Fog

In an effort to improve application methods for controlling sand flies in desert environments, a hand-held ultra-low volume (ULV) aerosol generator, a truck-mounted ULV aerosol generator, and a hand-held thermal fogger were evaluated. The velocity and temperature of the air and characteristics of droplets generated by these aerosol generators were measured at various distances from the nozzle. The droplet size characteristics were measured for three flow rates each of BVA-13 mineral oil and a mixture of water and nonionic surfactant with a phase Doppler particle analyzer. Moving 0.9 m away from the nozzle, the velocity of air produced by the two hand-held sprayers decreased to <5 m/s, whereas the truck-mounted sprayer still had an air velocity of 15 m/s. The air produced by truck-mounted cold fogger, thermal fogger, and hand-held ULV applicator was 38, 49.2, and 8.5 C above ambient temperature, respectively. Increases in flow rate, generally, did not affect the droplet size for the two hand-held units; however the droplet size increased as the flow Manuscript received August 15, 2011; accepted for publication May 3, 2012; published online October 18, 2012. U.S. Navy, Navy Entomology Center of Excellence, Jacksonville, FL 32212 (Corresponding author), e-mail: [email protected] Univ. of Florida, IFAS, Citrus Research and Education Center, Lake Alfred, FL 33850. U.S. Navy, Navy Entomology Center of Excellence, Jacksonville, FL 32212. Mention of a trademark, vendor, or proprietary product does not constitute a guarantee or warranty of the product by the US Navy and does not imply its approval to the exclusion of other products that may also be suitable. The views expressed in this article are those of the author and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, or the U. S. Government. Copyright VC 2012 by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. Pesticide Formulations and Delivery Systems: Innovating Legacy Products for New Uses STP 1558, 2012 Available online at www.astm.org DOI:10.1520/STP104278 Report Documentation Page Form Approved OMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE OCT 2012 2. REPORT TYPE 3. DATES COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Droplet Characteristics and Near Nozzle Dispersion of Cold and Thermal Fog 5a. CONTRACT NUMBER