Factors affecting the spray angles of hollow cone nozzles used in pesticide application

The aim of this study was to determine the effects of orifice diameter, swirl core and pressure on spray angle of

hollow cone nozzles produced from polyacetal (POM) material. Blue (2-slot), brown (3-slot), yellow (2-slot) and

stainless steel (2-slot) swirl cores with 1.0 mm, 1.2 mm, 1.6 mm, 2.0 mm and 2.4 mm orifice diameter nozzle

discs used. It was known that the lowest flow rate between the swirl core types was provided with blue core and

the largest flow rate was provided by stainless steel swirl core. All applications were made at spray pressures of 2,

4, 6, 8 and 12 bars. According to the results of analysis of variance, the effect of nozzle orifice diameter, swirl core

and pressure variables on the spray angle was found to be statistically significant. The largest spray angle was

measured in the nozzles with low flow rates. According to the swirl core, the largest spray angle was obtained

with blue core, while the lowest angle was measured in stainless steel core. In reference to the curve estimation

method, the polynomial functions with high R2

were obtained between nozzle orifice diameter and swirl core

combinations between spray angle and pressure. For nozzle discs with orifice diameter of 1.0 mm, 1.2 mm, 1.6

mm, 2.0 mm and 2.4 mm at 3 bar pressure level, the nominal spray angles were ranged between 49°-60°, 60°-72°,

74°-85°, 80°-97° and 89°-101°, respectively. After a certain pressure level, the spray angles varied in a stable range.

The stable spray angle variation was determined as 6 bar for the nozzle of 1.0 mm, 4 bar for the nozzles of 1.2

mm and 1.6 mm, and 2 bar for the nozzles of 2.0 mm and 2.4 mm diameters.