A technique for introducing low concentrations of additives to high pressure gas streams

Abstract

A technique is described for continuously adding low concentrations of additives to high pressure, low flow rate gas streams. The method utilizes the diffusion of gases and vapours through plastics and avoids the problems of mixing two gas streams at very low flow rates. It is shown to be successful in adding water vapour (0-1000 vpm) to dry carbon dioxide and carbon dioxide (0-100 vpm) to pure helium.