Justification of range limits of root spray angle of an adaptive spraying device

BACKGROUND: Oscillations of the sprayer field boom in the transverse-vertical plane causes a decrease in the quality of the technological operation. This is especially true in relation to the operation of small-sized single-support barrow-type sprayers. One of the possible solutions to compensate the effect of transverse oscillations of the boom on the quality of spraying is the use of adaptive sprayers with a variable root angle of the spray jet, responding to the position taken by the sprayer in relation to the surface being treated.

AIM: Justification of the necessary limits for changing the spray angles of an adaptive sprayer for a single-support spraying device. The novelty of the research lies in the fact that insufficient attention is paid to the implementation of technologies using means of small-scale mechanization, unlike industrial agricultural machinery.

METHODS: A prototype of a single-support boom motor sprayer was used as the study object. The field experiment was carried out at the experimental area of the Oryol State Agrarian University. Data acquisition on the deviation of the sprayer from the vertical axis was carried out using a specially developed angle gauge. A spreadsheet processor in the Microsoft Excel environment was used to perform mathematical processing of the decrypted experimental data. The study of the obtained analytical dependencies was carried out in the environment of the Mathcad 14.0 mathematical calculation system.

RESULTS: It has been experimentally found that the maximum deviations of the sprayer from the vertical can be up to 30° during operation. At the same time, the average amplitude of the transverse operating oscillations of the boom of a single-support barrow-type boom sprayer ranges from +11° to -18°. The amplitude of the transverse oscillations of a single-support sprayer depends on the operator’s skills and the unit motion velocity. Balancing the sprayer is important due to the moment of force caused by the weight of the one-sided field boom. A formula for calculation of the spray width of one sprayer, taking into account the geometric parameters of a single-support sprayer, as well as its inclination angle in the transverse-vertical plane, has been derived. An analytical relationship that makes it possible to calculate the required limits of the root angle of the spray jet of an adaptive sprayer, taking into account the installation distance of the sprayer relative to the vertical plane passing through the support point of the sprayer, has been obtained. The values of the root spray angles for the deflectors of adaptive sprayers, with the sprayer oscillations amplitude from -18° to +11° in the transverse-vertical plane, were found.

CONCLUSIONS: The practical value of the study lies in the potential of using the formula to determine the range limits of root spray angles when designing and developing adaptive sprayers.