Stabilization of Liquid Outflow Speed From a Slotted Spray Nozzle

Unequal distribution of the liquid outflow from the slotted spray nozzle forms a wide spectrum of drops. This affects the level and uniformity of spraying and the degree of drip drift compensation. The purpose of the work was to determine a method of stabilizing the speed of liquid outflow from the nozzle. The result of the study was construction of a speed stabilizer an insert mounted in the nozzle. Advantage of the patented design is, besides stabilizing the liquid outflow speed, also a uniform flux of liquid flow over the entire length of the nozzle. INTRODUCTION One way to protect plants is by spraying them with aqueous solutions of the appropriate substances. Achieving the biological effect of chemical plant protection depends largely on the quality of the spray nozzle work. They affect the level and uniformity of application of the solution and the degree of wind drift compensation, Dorr et al. (2013), Vallet et al. (2013), Szewczyk (2010). Commonly used sprayers in agriculture are slotted spray nozzles. The principal drawback of these nozzles is uneven distribution of liquid flow rate from the nozzle, Vallet et al.(2013), Kowalik (2014). This parameter has a decisive influence on the quality of spraying, since on it depends the resulting droplet spectrum, Dorr et al.(2013), Szewczyk et al.(2013), Truck et al. (1997). In case of slotted spray nozzles this spectrum is unfavorable since diameter of droplets ranges from a few to several hundred micrometers, Hawitt (2008), Orzechowski et al. (2008), Truck et al. (1997). In addition, outflow density in the central nozzle section in these sprayers is much higher than in the outside, which affects the selection and setting of the sprayer boom and the uniformity of spraying, Parafiniuk, Sawa, Wołos (2011), Parafiniuk, Sawa, Huyghebaert (2011). Satisfactory effect is achieved on a flat surface and a sprayer boom parallel to this surface, Szewczyk (2010). Droplet size is now controlled by the use of sprayers with nozzles of different geometrical dimensions, changing pressure of the liquid used, the use of anti-drip inserts, Orzechowski et al. (2008). The range of droplet size control by these methods does not reduce the drop spectrum, but limits the operating parameters of the sprayer. Another way to adjust the droplet size is to aerate them (injectors). With these sprayers, larger diameter droplets are more easily disseminated on the surface of leaves. However, large numbers of large droplets result in less stream density resulting in less droplets per unit area, which influences the biological efficiency of the process, Butler et al.(2002), Szewczyk et al. (2013). The aim of the study was to determine the conditions that should be met in order to obtain a constant liquid outflow speed from slotted spray nozzle and consequently reduce the drop spectrum.