| 摘要 |
<p>The specification discloses a method and apparatus for concentration of vapours present in trace quantities in the atmosphere in a continuous and rapid manner. It relates especially to a device to enhance the concentration of trace vapours to such a level that they may be more readily analyzed by appropriate instrumentation. This is of considerable value in connection with the detection of certain vapours which are associated with explosive devices and bombs. These are of considerable importance now in connection with security at airports and the like. The specification discloses a method and apparatus for the continuous concentration of trace gases in a gaseous medium, such as air, comprising the steps of bringing the air into intimate contact with a suitable free-flowing adsorption powder in an adsorption region, passing the air containing the treated powder and adsorbed vapours through a cyclone separator to produce a substantially powder-free air stream and a powder containing adsorbed vapours, then passing the powder through a desorption region whereby the powder carrying trace vapours is heated in a heating zone in the presence of a carrier stream at a temperature sufficient to release the adsorbed trace vapours of interest, and thus to produce a vapour-enriched carrier gas stream. The powder is then normally recycled into the air inlet stream.</p> |
