| 摘要 |
A closed circuit breathing apparatus such as that worn by personnel in irrespirable atmospheres. The apparatus is mounted on a backframe and housing 14 and is adapted to be interconnected with a face mask 12. The apparatus includes exhalation and inhalation passageways 18, 20, a source of breathing gas 50 which is released into the breathing apparatus at a constant volumetric flow rate, a carbon dioxide scrubber 30 and an ejector pump 40 which is driven by the source of pressurized breathing gas and which causes the pressurized breathing gas and exhaled air to be driven through the carbon dioxide scrubber at a relatively constant flow rate. The apparatus further includes a spring biased inhalation gas accumulator or counterlung 46 on the downstream side of the carbon dioxide scrubber, which counterlung is in communication with the inhalation passageway. An exhalation gas accumulator 42 is provided on the upstream side of the carbon dioxide scrubber, the exhalation gas accumulator being in communication with the exhalation passageway. The exhalation and inhalation gas accumulators are in fluid communication with each other so that at extremely high breathing rates exhaled gases can flow from one to the other whereby all system gases will be held at the same pressure. A warning device 78, 80 is provided, as well as a redundant circuit. |
