Effect of Swirl Chamber Geometric Configuration on the Spray Cone Angle Characteristics of a Swirl Nozzle for Use on Equipment for Teaching Chemical Pesticide Application Technology

Abstract. Authorities at the supervising organization of Universities in Nigeria have proposed intensive local development of workshop and laboratory equipment as one effective way of solving this problem of lack of laboratory and workshop equipment for practical classes and research. It is in this view that the objectives of this study were to develop a swirl nozzle for use on a locally developed test equipment on which Spray cone angle tests were carried out on three developed swirl nozzle prototypes with swirl chamber length: diameter ratios of 0.25, 0.50 and 1.00 respectively. Each swirl nozzle prototype was mounted in sequence on a calibrated test rig and had the spray cone angles formed by the discharge tested at a nozzle supply pressure of 300 kPa while installed with 7 orifice plates, each of which, had a single orifice of 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 mm diameter drilled respectively in its centre.The tests were repeated for nozzle supply pressures of 250 and 200 kPa respectively. When the generated spray cone angle data were subjected to statistical analysis, the results showed that both the swirl chamber length: diameter ratio and exit orifice diameter had significant effect on the spray cone angle formed by the nozzle discharge at a level of significance, α = 0.05. The best combination of the studied treatment levels for generating high spray cone angle was a 300 kPa nozzle supply pressure, swirl chamber length: diameter ratio of 1.00 and exit orifice diameter of 4.0 mm.