Download or read book Effects of Spray Adjuvants on Spray Droplet Size from a Rotary Atomizer written by Chenghai Yang and published by . This book was released on 2016 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rotary atomizers are used in a number of aerial applications, such as forest pest spraying and mosquito control sprays. These types of atomizers have a rotating cage at speeds of 2,000 to 10,000 revolutions per minute (rpm) through which a spray is emitted and atomized. Many applicators routinely add spray adjuvants to change the droplet size, reduce drift potential, or to reduce evaporative effects of a particular spray solution; therefore, six commonly used classes of spray adjuvants were evaluated to determine their effects on droplet size. If an applicator's only concern was minimizing spray drift, the applicator could choose a polymer or high surfactant oil concentrate for helicopter speeds and a polymer for fixed-wing applications. For applicators working under hot, dry conditions where evaporation is a concern, choosing an oil-based adjuvant to help get better coverage by creating smaller droplets that do not evaporate would be recommended. Understanding the role the different adjuvant types play in the final droplet size of the spray is key to successfully setting up and making applications with rotary atomizers.
Download or read book Spray Adjuvant Effects on Droplet Size Spectra Measured by Three Laser Based Systems in a High Speed Wind Tunnel written by J. B. Ross and published by . This book was released on 2008 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spray droplet size has long been recognized as the most important variable that aerial applicators can influence to mitigate spray drift from the application site. There are several different technologies that are used by researchers to measure droplet size from spray nozzles. The objective of these studies was to determine the influence of eight spray adjuvants on the droplet size spectrum produced by two nozzles in a high-speed wind tunnel when characterized using three different droplet size measurement systems. The adjuvant, nozzles, and airspeeds used in these studies are commonly used by aerial applicators. Three droplet sizing systems (Malvern laser diffraction, PMS optical array probe, and LaVision laser imaging) were simultaneously operated to measure the spray droplet size spectra for each adjuvant, airspeed, and nozzle combination. Two spray nozzles (a D6-46 nozzle and a D2 straight stream nozzle) were evaluated in a high-speed wind tunnel at airspeeds of 45 and 58 m/sec. There were significant differences in the droplet size spectra produced by the eight spray adjuvants tested. There were also significant differences between the droplet size values reported by the three measurement systems (Malvern, LaVision, and PMS) evaluated; however, there was considerable agreement trendwise. In general, the Malvern reported smaller spray droplet size spectra values than the LaVision, while the PMS system generally reported the largest spray droplet size spectra values. These tests are the first reported studies where all three droplet sizing systems were operated simultaneously.
Download or read book The Effect of Adjuvants Pesticide Formulation and Spray Nozzle Tips on Spray Droplet Size written by Kelli L. Nelms and published by . This book was released on 2009 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many factors, including adjuvants, pesticide formulations, and nozzle tips, affect spray droplet size. It is important to understand these factors as spray droplet size affects both drift and efficacy of pesticides, which is a main concern with pesticide application. A laser particle analyzer was used to determine the spray droplet size and distributions of a range of formulations sprayed through several types of nozzle tips. Nozzles included were extended range flat fan sizes 11003 and 11005 (Spraying Systems XR), air induction flat fan sizes 11005 and 11004 (AI), air induction extended range flat fan size 11005 (AIXR), preorifice flat fan size 11005 (TT), and a second preorifice flat fan size 2.5 (TF). Several deposition/retention adjuvants were studied, including Array, Interlock, In-Place, and Thrust. Another study looked at diflufenzopyr + dicamba (Status, BASF) in combination with several adjuvants. Also, three fungicides were evaluated at differing spray volumes. Results indicated that the droplet size of some nozzle tips is more affected than others by changes in the contents of the spray solution.
Download or read book The Effect of Adjuvants at High Spray Pressures for Aerial Applications written by W. Clint Hoffmann and published by . This book was released on 2016 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Controlling droplet size is a critical part of making any successful agrochemical spray application. This is particularly true for higher-speed aerial applications where secondary atomization from air shear becomes the most dominant factor driving spray droplet size. Previous research has shown that higher spray pressures can result in larger droplet-sized sprays by increasing the exit velocity of the spray liquid from the nozzles, which in turn decreases the differential velocity between the spray liquid and surrounding airstream, reducing secondary breakup. This work explores the effects of higher-than-normal spray pressures on two typical aerial application nozzles in the presence of a formulated herbicide spray solution, with and without additional adjuvants. Generally, the spray solution effects followed trends seen in previous studies, with crop oil-containing adjuvants resulting in the largest droplet-sized sprays and the silicones and polymers the smallest. Increasing spray pressure increased droplet size across all combinations of nozzle, airspeed, and spray solution, without exception. The most promising results from this work showed that for typical high-end application airspeeds, increasing spray pressure from the lowest to highest pressures tested generally resulted in spray classifications increasing at least one size coarser. The results from this work demonstrate that larger, faster-flying agricultural aircraft can adopt current methods, with potentially minor equipment adjustments, to generate medium and larger spray qualities and to allow for more efficient applications while meeting agrochemical product label requirements.
Download or read book The Impact of Spray Adjuvants on Solution Physical Properties and Spray Droplet Size written by Bradley K. Fritz and published by . This book was released on 2018 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past several years, numerous anecdotes from aerial applicators have surfaced concerning observations of increased numbers of fine droplets seen in the applied spray clouds, often associated with tank mixtures that contain crop-oil concentrates (COCs) and foliar fertilizers (FFs). Efforts were made herein to correlate surface tension and viscosity to spray droplet size under a variety of aerial application conditions, but these efforts were unsuccessful. In addition, spray mixtures were examined to compare relative evaporation rates. Researchers are encouraged to actively pursue this line of work. The addition of several adjuvants and FFs were found to significantly affect spray droplet size, so applicators should pay careful attention to spray tank composition when making aerial spray applications.
Download or read book Effects of Adjuvants and Dynamic Surface Tension on Spray Properties Under Simulated Aerial Conditions written by WR. Dexter and published by . This book was released on 1998 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The literature on the effects of active ingredients, adjuvants and surface active agents on the droplet size of agricultural sprays is reviewed. The effects of various agricultural adjuvants on the droplet size distributions of a herbicide sprayed in a wind tunnel simulating an aerial application were determined using a Malvern laser diffraction instrument. All adjuvants caused a decrease in droplet size, which varied with adjuvant type and concentration. Measurements of equilibrium surface tension, dynamic surface tension at 20 ms, density, and viscosity were recorded. Droplet size did not correlate linearly with equilibrium surface tension: only at the lowest surface tensions was any significant decrease in droplet size observed. Droplet size correlated better with dynamic surface tension for each adjuvant over most of the surface tension range, but with different slopes for each adjuvant. At high concentrations of surfactant, bubbles of air were observed within captured droplets and the size distribution became bimodal.
Download or read book Adjuvants for Agrichemicals written by Chester L. Foy and published by CRC Press. This book was released on 2018-05-04 with total page 737 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on a conference, this book is intended to promote a better understanding of the effects of adjuvants on pesticide penetration, translocation, photodegradation and stability, spray deposition and dissipation, and the fate of herbicides in the environment.
Download or read book Impact of Adjuvants on Droplet Spreading and Droplet Deposit Area After Spray Application written by Peter Baur and published by . This book was released on 2008 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of adjuvants on spreading of small droplets after spray application and of larger drops with volumes in the microliter range was studied. The characterization of spreading as affected by adjuvants is done often with lab tests on artificial surfaces. In these tests much larger drops in the microliter range are used and plant factors such as the presence of hairs or crystalline waxes and spray related factors such as rapid evaporation, a different drop size magnitude, a drop size distribution in reality, and effects of adjuvants on drop size are not considered. For a set of test compounds from different chemical classes we evaluated stepwise the approximation to real systems with plant surfaces representing the major surface features. With larger drops of 10 and 20 μl we obtained a surprisingly good correlation of spreading on Parafilm® M and the mature leaves of Chlorophytum, tomato, rape, and corn. With good wetters better spreading was observed on leaves than on Parafilm M. The correlation of spread diameters with real spray (flat fan nozzle, 300 l/ha) on an easily wettable plant and drops on Parafilm M was very good as well though with the best spreaders the gravimetric momentum on spreading and longer times for evaporation overestimated spreading of the larger droplets on Parafilm M. If the mean spread diameters of real spray was plotted vs. the logtransformed spread diameter on Parafilm M a linear correlation was obtained (r2=0.92).
Download or read book The Measurement of Droplet Size Distributions from Rotary Atomizers written by ME. Teske and published by . This book was released on 2001 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Various experimental techniques have been developed to recover droplet size distributions emitted from rotary atomizers. These techniques include both single line-of-sight measurements through the center of the spray cloud and volume weighted averaging from multiple passes through portions of the spray. Because the droplet size distribution of a spray is one of the most important inputs into aerial spray prediction models such as AgDRIFT®, a consistent, widely-accepted standard for rotary atomizers should be developed and implemented with regard to this measurement. No such standard currently exists. The present paper summarizes current measurement techniques and develops a simple computer model to predict droplet movement following emission from a rotary atomizer in a wind tunnel. Qualitative comparisons are made with available data to demonstrate the effects of single line-of-sight measurements and weighted averaging from multiple passes.
Download or read book Adjuvants and Agrochemicals written by Paul N. P. Chow and published by CRC Press. This book was released on 2018-01-18 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies of Adjuvants involve many scientific fields from basic research of the chemistry, through investigations into physiological effects and environmental impact, to mixture formulation and field use. These important areas are illustrated in these two volumes, which are contributions from the First International Symposium on Adjuvants for Agrochemicals, held in Brandon, Manitoba on August 5 to 7, 1986. A total of 200 participants from 19 countries met to discuss their common interest in adjuvant science, technology, and application. It is the editors hope that these volumes will stimulate interest in and promote a better understanding of the chemical, physiological, and agronomic aspects of adjuvants as they relate agrochemicals. In addition, the revisedAdjuvants for Agrochemicals: A Selected Bibliography of World Literature in the English Language will be a valuable resource for agricultural researchers and other users. We hope that adjuvant research will lead to even safer, more efficient, and more economical use of chemicals in agriculture and forestry.
Download or read book Drift Control Adjuvant Benchmarking in Agricultural Spray Applications written by Kevin Penfield and published by . This book was released on 2014 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drifting of fine droplets during the application of pesticides is an issue of increasing commercial and regulatory importance. Spray drift damages susceptible crops, wastes resources, and results in inconsistent weed control. Several strategies are currently used to mitigate this problem. These include enhanced nozzle technology, improved application techniques, and inclusion of drift control additives in the final tank mix. Elimination of small diameter droplets ("driftable fines") is a key goal. Measurements were made of droplet size distributions of sprayed pesticide formulations containing commercial products representative of the leading drift control technologies, including guar, polyacrylamides, lecithin, and oil/surfactant mixtures. Effects of spray nozzle and pressure were also evaluated. Nozzle technology plays a large role in determining the spray droplet size spectrum. However, there is a strong interplay between nozzle design and formulation variables. We found that drift control agents have greater impact on spray from flat fan nozzles. Also, the ranking of adjuvants depends on the nozzle technology in use: for glyphosate/ammonium sulfate solutions, polymers were more effective in reducing fines from a flat fan nozzle, while surfactant-based products were marginally superior when an air induction nozzle was used. The regulatory community is currently focused on mitigating the generation of small droplets. However, the generation of oversized droplets also effects spray efficacy. The impact of drift control agents on the breadth of the droplet size spectrum is an aspect of drift control which is often overlooked. We found that emulsion-based products tighten the droplet size distribution, while the polymer-based products shift the mean droplet diameter up, broadening the distribution in the process: while the latter effect may earn better ratings from regulatory agencies concerned exclusively with spray drift mitigation, it may be less helpful in enhancing application efficacy.
Download or read book The Effects of Adjuvants Application Timing Droplet Sizes and Spray Volumes on Acifluorfen and Imazethapyr Efficacy written by Eric H. Schimek and published by . This book was released on 1998 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spray Characteristics of Rotary Atomizers written by LE. Bode and published by . This book was released on 1983 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Evaluations of the spray characteristics of a new atomizer (Micromax) indicate that rotary atomizers used on tractor-mounted sprayers have the potential to apply agricultural pesticides effectively. Operating the units at the spacing, height, and tilt angle that provides double to triple overlap of the spray output results in acceptable distribution patterns over a range of disk speeds and flow rates. The droplet spectrum produced by the Micromax is much narrower than the spectrum produced by conventional hydraulic nozzles, and the median size generated is related to the speed of the disk. Spray droplets from the Micromax tend to move off the swath and deposit in the first few metres downwind much more than those from flat fan sprays. At distances greater than 10 to 20 m downwind, the deposits were no different from those from a flat fan spray.
Download or read book Pesticide formulations and application systems written by Bala N. Devisetty and published by ASTM International. This book was released on 1993 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Papers presented at the Twelfth ASTM Symposium on [title], held in San Diego, California, October 1991. The volume is divided into four sections: novel surfactants and their properties (four papers); pesticide formulation technologies (14 papers); pesticide packaging and management (one paper: Container Design and "Glug"); and pesticide application technologies (eight papers). Annotation copyright by Book News, Inc., Portland, OR.
Download or read book Adjuvant Effects on Spray Characteristics and Drift Potential written by PCH Miller and published by . This book was released on 2001 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes studies that were conducted to investigate the effects of different surfactant and emulsion adjuvant chemistries and formulations on spray characteristics and drift potential of a commercial herbicide. Previous research has shown that surfactant, emulsion, and polymer adjuvants can affect the formation of sprays and liquid distribution patterns when atomized through flat fan nozzles. The present research involved the application of various different tank mix-adjuvant combinations through flat fan, disc-core, and air induction nozzles. The sprays were characterized using spark photography, droplet size analysis, liquid patternation, and driftability measurements in a wind tunnel. Atomization was related to the physical properties of the tank mixes and sheet breakup mechanisms. The results will help in the development of ASTM test guidelines for spray characterization and drift research, and provide valuable information for applicators to consider when selecting tank mix-nozzle combinations for the application of agricultural chemicals.
Download or read book The Effects of Spray Droplet Size on Application of Growth Retardants to Floricultural Crops and an Investigation of Spray Coverage from Electrostatically Charged Droplets written by Lorraine Denise Brisson and published by . This book was released on 1983 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Nozzle Type and Operation on Spray Droplet Size written by Louis F. Bouse and published by . This book was released on 1991 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
