Characteristics of a double-orifice nebulizer.
Pilacinski-W; Szewczyk-KW; Lehtimaki-M; Willeke-K
J Aerosol Sci 1990 Jan; 21(7):977-982
The influence of inter/orifice distance and input air pressure on the concentration and size distribution of aerosol generated by a pneumatic nebulizer with a double orifice nozzle was investigated. The nebulizer, also known as a Wright nebulizer, was modified to adjust the liquid to air flow ratio by changing the distance between inner and outer orifices. Decreasing this distance increased the liquid flow resistance and decreased the liquid flow rate, resulting in a decrease of aerosol concentration without changes in size distribution. Corn-oil was used as the aerosolized liquid for testing. The liquid to gas flow ratio increased with input pressure. The aerosol generation rate increased 300 times as the input pressure increased. The nozzle spacing affected aerosol generation rate only below some critical value that was dependent on the design. Increasing the distance between nozzle and baffle increased the fraction of larger particles in the generated aerosol. Changes in inter/orifice spacing below a critical value strongly affected the aerosol concentrations without significant changes in size distribution for the analyzed size range of 0.8 to 9.0 micrometers. The authors conclude that the characteristics of aerosol generated by a double orifice pneumatic nebulizer may be varied.
NIOSH-Publication; NIOSH-Grant; Respirators; Respiratory-equipment; Aerosol-particles; Aerosol-generators; Aerosols; Air-flow; Physical-properties
Environmental Health University of Cincinnati Dept of Environmental Health Cincinnati, Ohio 45267
Journal of Aerosol Science
University of Cincinnati, Cincinnati, Ohio