Actuator System for Individual Nozzle Control of Flow Rate and Spray Droplet Size

2012 ◽  
Vol 55 (2) ◽  
pp. 379-386 ◽  
Author(s):  
D. L. Needham ◽  
A. J. Holtz ◽  
D. K. Giles
1993 ◽  
Vol 7 (4) ◽  
pp. 799-807 ◽  
Author(s):  
James E. Hanks ◽  
Chester G. McWhorter

Spray droplet size of water and paraffinic oil was affected by air pressure, nozzle type, and liquid flow rate when applied with an ultralow volume (ULV), air-assist sprayer. Volume median diameters of water were generally larger than oil at constant air pressure and liquid flow rate. Droplet size decreased as air pressure increased, but increased as liquid flow rate increased. Volume median diameters of water droplets ranged from 41 to 838μm and from 16 to 457μm with oil when atomized at air pressures ranging from 14 to 84 kPa. Relative spans ranged from 1.2 to 18.0 and 2.0 to 7.2 for water and oil, respectively.


2018 ◽  
Vol 61 (4) ◽  
pp. 1243-1248
Author(s):  
Scott L. Post ◽  
Rory L. Roten

Abstract. The chargeability of liquid sprays is an important factor in determining the deposition efficiency of electrostatic pesticide sprays. The Rayleigh limit provides information on the maximum amount of charge a spray droplet can carry as a function of droplet size and liquid properties. This article reviews the literature to determine what fraction of the Rayleigh limit is achievable. Typically, less than 10% of the Rayleigh limit charge is obtained. The droplet charge per unit mass decreases with increasing droplet size and liquid flow rate. A correlation equation is derived from published data to predict spray droplet charge per unit mass from droplet size, flow rate, and charging voltage. Keywords: Droplet size, Electrostatic charging, Spray drift, Sprayers, Ultra-low volume spraying.


1977 ◽  
Vol 20 (2) ◽  
pp. 0232-0237 ◽  
Author(s):  
D. L. Reichard ◽  
H. J. Retzer ◽  
L. A. Liljedahl ◽  
F. R. Hall

2016 ◽  
Vol 56 (2) ◽  
pp. 178-185 ◽  
Author(s):  
Bradley Keith Fritz ◽  
Zbigniew Czaczyk ◽  
Wesley Clint Hoffmann

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.


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