Characteristics of the Centrifugal Air-Pressure Nozzle

摘要

The principle features of atomizing nozzles are: fineness of spray, determined as a function of the mean or maximum droplet diameter; size distribution of droplets in flame; distribution of the characteristic mean or maximum droplet diameters over the flame cross section; flame spraying density q, kg/m(superscript 2)-sec, and the hydraulic drag of the nozzle, characterizing the effectiveness of a given nozzle design. A test rig for the experimental determination of these characteristics was developed. This rig was used to investigate the flare angle of flame and the spraying density for an air-pressure nozzle on varying the parameters within given ranges. The flare angle of flame was measured according to photographs, while spraying density was measured by trapping spray particles in test tubes positioned along the diametral cross section of the flame. The distribution of mean surface droplet diameter over the flame cross section was determined by trapping droplets on glass slides coated with a mixture of vaseline and transformer oil. It was established that neither the temperature of the atomized air nor the surface tension of the liquid affect markedly the flare angle of flame and the density of spraying. (Author)