Spray volume distribution pattern and droplet size spectrum from ceramic nozzles

Abstract

Droplet size spectrum and uniformity of spray volume distribution are important parameters for selecting spray nozzles. The objective of this study was to evaluate the average spray volume distribution and droplet size spectrum from ceramic nozzles. The spray volume distribution pattern was evaluated on a test table for hydraulic spray nozzles using spray heights of 0.4, 0.5, 0.6, 0.7, and 0.8 m, and working pressures of 500, 600, and 700 kPa. Computer simulations were used to analyze the spray volume distribution using arrangements of bar heights, working pressures, and spacing between spray nozzles in a bar of 12 m. The droplet size spectrum from the spray nozzles was evaluated using a randomized complete experimental design in a 2 × 3 split-plot arrangement consisting of two types of nozzles (ATR-1.0, and TVI-800075) and three working pressures (500, 600, and 700 kPa), with four replications. The uniformity of spray volume distribution was improved when using ATR-1.0 spray nozzles spaced 0.4 or 0.6 m apart, regardless of the working pressure. Regarding the droplet size spectrum, the volume median diameter decreased with increasing the working pressure for both types of nozzles, reaching 210 μm (ATR-1.0) and 483 μm (TVI-800075). Contrastingly, the percentage of droplets with diameter smaller than 100 μm increased with increasing working pressure; the target coverage presented the same trend, with 8.4% of coverage when using ATR nozzles with working pressure of 700 kPa.

Aeronave Remotamente Pilotada (RPA) para aplicação de agrotóxico

“…Costa et al (2007) relatam que gotas muito finas e finas propiciam maior cobertura do alvo, mas tendem a ser levadas facilmente pelo vento (deriva). Massola et al (2018) relatam que espectro de gotas e a uniformidade de distribuição volumétrica são parâmetros importantes na seleção da ponta de pulverização.…”

Mistura de Agrotóxicos e Tecnologia de Aplicação

“…Para aferir o espectro de gotas pulverizadas e a qualidade da aplicação deve ser considerado o tipo de ponta, a vazão, o ângulo do jato formado, a pressão de trabalho e as características da calda pulverizada (WOMAC et al, 1999). Para determinar a uniformidade de formação de gotas, alguns parâmetros são considerados, como o diâmetro mediano volumétrico (DMV), diâmetro mediano numérico (DMN), coeficiente de homogeneidade (CH), amplitude relativa ao diâmetro de gotas do jato aplicado (SPAN) (MASSOLA et al, 2018).…”

Effect of angled spray nozzle designs on spray distribution and droplet spectrum

“…For each type of spray nozzle, three different units in five replications each were evaluated, totaling 15 replications for each treatment. Since the spray mixture used in applications majorly affects the droplet spectrum (FERGUSON et al, 2015;MASSOLA et al, 2018) it was decided to conduct the test with two spray solutions: i) only water; and ii) fungicide tryfloxystrobin (150 g L -1 ) associated with prothioconazole (175 g L -1 ) (Fox ® ; dosage: 0.4 L ha -1 ), suspension concentrate (SC), associated with the soybean oil methyl ester adjuvant (Aureo ® ; 0.3% v v -1 ), emulsifiable concentrate (EC), simulating an application for disease control in soybean crop (NEGRISOLI et al, 2019). Spraying was performed by a pressurized compressed air system, adjusting the pressure according to each treatment (Table 1) by a precision regulator.…”

“…Considering that spray volumetric distribution uniformity was evaluated according to the theorical operational parameters for spraying in the field, it can be inferred that the treatments used are capable of promoting an adequate and uniform spray distribution. However, this condition comes from a theorical point of view, since other factors such as climate and field ground (variation in boom height and nozzle spacing/boom height ratio) may significantly affect the uniformity of spray distribution in the field (FORNEY et al, 2017;MASSOLA et al, 2018).…”

“…The quality of a spray application is directly influenced by the components of the sprayer (FERGUSON et al, 2015;MASSOLA et al, 2018), application parameters (FORNEY et al, 2017;HASSEN;SIDIK;SHERIFF, 2013) and climate conditions (DE COCK et al, 2017). In this scenario, pesticide application technology plays a key role in determining the best parameters for each situation, which may vary according to the target as well as the pesticide being used (DE COCK et al, 2017;NUYTTENS;ZWERTVAEGHER;DEKEYSER, 2017).…”