| 摘要 |
<p>In a breathing apparatus of the closed circuit type wherein breathable air is recirculated with the removal of carbon dioxide and the replenishment of oxygen, the breathable air is cooled by causing it to flow through a conduit (1) in heat exchange relationship with a reservoir (2) containing a liquid refrigerant medium which has a boiling point below the maximum desired temperature of the breathable air supply. The reservoir is vented to allow escape of refrigerant gas through an adjustable pressure relief valve (4). whereby cooling of the breathable air supply is effected through a progressive boiling away of the refrigerant liquid from the reservoir, the boiling point of the liquid being controlled by means of a corresponding adjustment of the pressure relief valve.</p> |
