GB500560A - Improvements in or relating to cooling and moisture regulating devices for the circulated air in self-contained breathing apparatus - Google Patents

Abstract

500,560. Respiratory appliances. BROWN, G. L., and DAVIS, SIR R. H. Aug. 10, 1937, No. 22031. [Class 81 (ii)] In self-contained breathing apparatus the air, after regeneration, preferably by non- hygroscopic carbon dioxide absorbent in a chamber a, is passed through a cooling chamber B, preferably of rectangular form having a re-entrant portion forming a recess C for cooling medium and connected with a separate chamber E in which moisture condensed in chamber B is trapped and from which such moisture is evaporated into the respiratory circuit under certain conditions such as high external temperature. The base of the chamber B preferably comprises a longitudinal trough e', having in its central portion holes e<2> leading to the chamber E. The external walls are preferably of poor, and the internal walls of good heatconducting materiat. A drain-off pipe e<3> may be provided in chamber E. The cooling agents employed may be salts, such as Glauber's salt, ice, or solid carbon dioxide, used separately or in combination, and may be placed directly in the recess C or in a heat-conducting casing D having a filling opening d. The casing D may occupy the whole or a part only of the recess, leaving space for unenclosed cooling agent.