Modeling and Prediction of the Uniformity of Spray Liquid Coverage from Flat Fan Spray Nozzles

Abstract

The effectiveness and quality of agricultural spraying largely depends on the technical efficiency of the nozzles installed in agricultural sprayers. The uniform spraying of plants results in a decrease in the amount of pesticides used in agricultural production and affects environmental safety. Both newly developed sprayers and those currently in use need quality control as well as an assessment of the performance of the spraying process, especially its uniformity. However, the models applied presently do not ensure accurate estimates or predictions of the spray liquid coverage uniformity of the treated surface. Generally, the distribution of the atomized liquid quantity is symmetrical and leptokurtic, which means that it does not fit well to the commonly used standard distribution. Therefore, there is a need to develop and design new tools for the evaluation, modeling, and prediction of such a process. The research problem studied in the present work was to find a new model for the distribution of atomized liquid quantity that could provide capabilities better than have been available so far to assess and predict the spraying process results. The research problem was solved through the formulation of a new function for the probability density distribution of sprayed liquid accumulation on the surface of the preset dimension size. The development of the new model was based on the results from a series of water atomization tests with an appropriate measurement device design based on the widely applied flat fan nozzles (AZ-MM type).

Site- and time-specific early weed control is able to reduce herbicide use in maize - a case study

“…The first stage consisted of creating a precision spraying grid by dividing the field into regular cells. The cell size was chosen after considering the fundamental factors that determine the base area coverage for a sprayer: (i) the spraying angle, (ii) the altitude of the boom, and (iii) the possibility of controlling a single nozzle or a boom section (Bajwa, 2014;Gonzalez-de-Soto et al, 2016;Kluza et al, 2019;Partel et al, 2019).…”

Optimization of the Opening Shape in Slot Spray Nozzles in a Field Boom Sprayer

“…The distribution of the quantity of atomized liquid from single-slotted spray nozzles is symmetrical and leptokurtic, which causes the distribution of the liquid quantity under the entire boom to lose uniformity. This has led to the development of new tools for modeling and predicting this process, as well as the design of enhanced slotted sprayers [7,[13][14][15][16]. However, production processes do not ensure that even the best designed sprayers meet all parameters perfectly.…”

“…The current standards for ground spraying units in field crops used for spraying the entire surface assume that 24 single-slotted nozzles are placed on the linear boom of a field sprayer, measuring 12 m in width, with 0.5 m spacing (Figure 1a). Notably, proper use of the stream of droplets exiting a group of cooperating slotted spray nozzles requires a more comprehensive knowledge of the stream formation produced by single-slotted spray nozzles [13]. The distribution of the quantity of atomized liquid from single-slotted spray nozzles is symmetrical and leptokurtic, which causes the distribution of the liquid quantity under the entire boom to lose uniformity.…”

“…However, none of the mentioned models have generated results adequate for the actual data. Hence, it was proposed that the distribution in the form of symmetric spline function from polynomials of p and q degree be used to model single nozzles [13]. For p = q = 2, the parameters of this distribution are indicated there, allowing one to obtain the coefficient of variation of the entire boom at the level of 2.16% for a measuring table equipped with 0.05 m wide grooves (Figure 2), which corresponds to the coefficient of variation of the entire boom at the level of 1.85% for the measuring table equipped with 0.1 m wide grooves.…”

“…In the conducted implementations where the ISO 16122-2:2015 standard [21] was applied, it was possible to achieve 5 to 14.5 thousand-fold improvement over the result achieved by Kluza et al [13].…”