Abstract
This paper describes the experimentally developed relationships between Reynold's Number (Re) and droplet size of different hollow cone nozzles. The experiments were conducted at 250 kPa, 300 kPa, 350 kPa, 400 kPa, 450 kPa, and 500 kPa spray fluid pressures. The University Boom Sprayer Test Bench was employed for conducting lab experiments in the laboratories of the Department of Farm Machinery & Power and the University Boom Sprayer was employed for field experiments at the Post-graduate Agricultural Research Station experimental fields, University of Agriculture, Faisalabad. The dimensionless ratio of droplet size to nozzle aperture diameter (diD) followed straight line trend up-to Reynold's Number 40,000, for locally made nozzle (d=1.6 mm), up-to 33,000 for imported yellow nozzle (d=1.3 mm), and upto 18,000 for imported orange nozzle (d=0.7 mm). The droplet size decreased with the increase in fluid pressure but remained constant at pressures above 450 kPa. Therefore, it would be uneconomical to spray the crop above 450 kPa due to the use of costly high pressure hoses. The critical fluid velocities for spray fluid atomization were found to be 20.36 mis, 23 mis, and 33.16 m/s for locally made nozzle, imported yellow nozzle, and imported orange nozzle respectively. Key words: Reynold's Number; hollow cone nozzle; atomization;
