Abstract
Industrial process air is used as the energy source for Ranque-Hilsch vortex tubes applied to personal protective equipment and in turn supplies breathing air for the individual wearing the protective clothing. The possibility that contaminants in the supply air might be concentrated by gas separation hi the hot or cold air discharges was investigated. Mercury vapor at low concentrations was introduced into the supply air, and the mercury concentrations were monitored at the inlet and at each of the outlets of the vortex tube. A statistical analysis of variance of the data showed that a very small but insignificant (p<0.01) gas separation occurred. The influence of pressure, air volume, and cold air fraction on the mercury concentrations at the outlets was insignificant. This study indicates that the use of industrial process air, meeting accepted air quality standards for breathing purposes, would not increase the hazard to personnel using the vortex tube in conjunction with personal protective equipment.