| 摘要 |
<p>A system for treating air for supply to an enclosed space in which it is to be breathed, comprises an inlet through which air can enter the system from atmosphere for supply to the enclosed space, and a regenerative adsorption assembly comprising at least two chambers (14,16) which contain an adsorbent material, arranged so that air flowing in the inlet for supply to the enclosed space can pass through one of the chambers for adsorption of contaminants before supply to the enclosed space while adsorbent material in another of the chambers is purged of adsorbed contaminants. A recirculation path is provided for supplying air from the enclosed space to the inlet to be mixed with air from atmosphere before it is supplied to the enclosed space. The system includes means for adjusting the resistance to flow of air through the recirculation path according to the resistance that is provided to the flow of air from atmosphere into the enclosed space.</p> |
