A Venturi Disperser as a Dry Powder Generator for Inhalation Studies

Abstract

This paper describes the design and operation of a dry power disperser based on the Venturi principle. The flow in the Venturi tube creates suction near the constricted area to feed powders into the device, and the shear flow downstream of the Venturi tube disperses particles into aerosol form. Powders are fed into the Venturi disperser by a screw feeder. The Venturi tube is simple in design and easy to operate. We have adopted the Venturi/screw feeder as an aerosol generator that can be operated in the flow rate range of between 60 and 200 I/min, as a function of the compressed air pressure and the geometry of the Venturi tube. At low flow rates, this generation system can be adapted for nose-only inhalation exposure to dry powders, and in fact was used to generate quartz and TiO₂ for 7-month inhalation studies. Our results indicated that the Venturi tube was useful in providing stable aerosol generation of sticky powders.