Air and liquid volumetric distribution in vertical in a hydro-pneumatic sprayer

Abstract

The objective of this research was to evaluate the air flow and spray vertical distribution produced by a hydro-pneumatic sprayer. The sprayer was attached to a John Deere tractor, model 5705. The rotation of the fan was set at 226.19 rad s-1 (2.160 rpm). The study was performed on both sides of the sprayer, with the intent of identifying possible asymmetries in the air flow distribution. Measurements of air speed were taken at three positions along the fan periphery. The uniformity of liquid vertical distribution was analyzed at pressures of 633, 844 and 1.055 kPa using a vertical collector placed two meters from the center of the fan impeller. The experiment was arranged in a randomized blocks design, with three replications. The air average speed, taken at the ventilation outlet was of 35.5 m s-1 and the average vertical speed taken at 0.5 meters from the bar was of 5.9 and 5.1 m s-1 to the left and right side, respectively. Variation coefficients for the vertical distribution volume were 136, 136 and 141% for the working pressures of 633, 844 and 1055 kPa, respectively.

Vertical volumetric distribution of an axial fan sprayer on the Brevipalpus phoenicis control

“…These values were 68 %, 66 % and 79 % lower than others previously reported in the literature, when working with a line of tubes fixed to a vertical post for collecting the sprayed liquid (Alvarenga et al 2014). This difference may be due to the method for collecting the sprayed liquid, indicating that the best method to do so, in the case of an axial fan sprayer, is via a surface that covers all or part of the spray nozzle width.…”

“…For the height of 1.6-3.2 m, the left side of the sprayer extension indicated a CV of vertical volumetric distribution 20 % greater than the height of 0-1.6 m, what can be attributed to the upward direction of the airflow (Alvarenga et al 2014) (Table 3). Airflow increases from the lower end to the upper section of the arc, resulting in deposition of higher spray volumes at the height of 1.6-3.2 m (Figures 1 and 2).…”

“…This can be attributed to the fact that the drops are carried by airflow (Sotolongo & Herrera 1986), and the right side has a higher airflow due to the clockwise spinning direction of the fan 2013) (Figure 1). Furthermore, the arc shape and positioning of the nozzles, in relation to the position and direction of the fan rotation, also influence the distribution of the sprayed liquid (Alvarenga et al 2014). The nozzles located along the lower portion of the arc are positioned at a greater distance from the fan blades, and are therefore subject to reduced airflow.…”

“…The nozzles located along the lower portion of the arc are positioned at a greater distance from the fan blades, and are therefore subject to reduced airflow. Additionally, due to the air outlet curvature, the lower nozzles present a greater distance to the target and are more subject to environmental action, where the spray droplets may be carried by the wind (Alvarenga et al 2014). This fact can be observed in the treatment in which nozzles were employed, that produced larger drops at the bottom of the arc (configuration 3), resulting in an increased distribution uniformity of 47 %, in relation to the right side of configuration 1 (Table 2).…”

Determinação do índice de volume de pulverização para a cultura do café

“…Furthermore, the arc shape and positioning of the nozzles in relation to the position and direction of the fan rotation also influence distribution of the sprayed liquid (Alvarenga et al 2014). The nozzles located along the lower portion of the arc are positioned at a greater distance from the fan blades, and therefore they are subject to reduced air flow.…”