Applicability of a 3D Laser Scanner for Characterizing the Spray Distribution Pattern of an Air-Assisted Sprayer

Abstract

Three-dimensional (3D) laser technology has been tested for assessing the performance of air-assisted spraying. A static test using an air-assisted sprayer equipped with two axial fans (front and back) with opposing directions of rotation was developed. The sprayer was adjusted to spread water in a static mode, at a pressure of 10 bars, with four air volumetric flow rates. Measurements were performed using a Leica HDS6000 3D laser scanner. In addition, the flow and velocity of air generated by the air-assisted sprayer were measured using a hot-wire anemometer and a 3D sonic anemometer with the objective of estimating the influence of air flow on the spatial distribution of spray droplets. To carry out the analysis, all of the droplets detected by the laser were considered to be of the same size. The distribution of products was asymmetric when the machine only worked with the back fan, with 41% of the product distributed on the left side versus 59% on the right side, as referenced to the direction of the machine’s advance. This asymmetry was corrected when the machine functioned with the two fans activated. These spray data were concordant with the measured air flow generated by the machine in the different working conditions. For the different regulation settings of the machine, taking the vertical of the machine as 0°, the angular region comprised between 40° and 60° was the one that received the highest quantity of product. The increase of the air flow produced a greater distance of the product. For the highest air flow configuration, 99% of the product detected by the laser was detected within a distance of 16 m from the axis of the machine.

Factors Affecting Droplet Loss behind Canopies with Air-Assisted Sprayers Used for Fruit Trees

“…These studies provided useful implications for the improvement of air-assisted spraying technology and the selection of application parameters. The canopy characteristics had a great influence on droplet drift in actual operations [25][26][27]. However, these characteristics were not considered in the studies.…”

Dynamic evaluation of airflow stream generated by a reverse system of an axial fan sprayer using 3D-ultrasonic anemometers. Effect of canopy structure

“…Therefore, airflow behaviour is a key element on the efficiency of pesticide treatments with air-assisted sprayer. In this way, most research focus on the analysis of airflow influence, such as in spray distribution (Pergher and Gubiani, 1995;Cross et al, 2003;Farooq and Landers, 2004;Balsari et al, 2008;Pergher and Petris, 2008;Celen et al, 2009;Miranda et al, 2015Miranda et al, , 2017García-Ramos et al, 2018) or the droplet size (Reichard et al, 1977 and1992;Cross et al, 2001;Czaczyk, 2012;Miranda et al, 2018;. Moreover, most of the above studies do not include a physical description of air behaviour.…”

Toward New Ideas on the Control of Pesticide Application: A Low-cost Tunnel Sprayer for Vineyards

“…During recent years several devices, such as air conveying devices and anti-drift nozzles were proposed and tested [9], [11], together with electronic sensors to adjust the spray to the crop [10], [14, [13]. In this view, recycling sprayers appear to be very promising [21], [17], because they can recover part of the active ingredient thus reducing the real applied dose.…”