| 摘要 |
A respirator comprises a respirator which includes a closed circulation circuit for breathing gas which has in any phase of the breathing process a slight overpressure compared to the ambient atmosphere. The excess pressure in the circuit is maintained by a combination of lung controlled amount of air and an amount of oxygen added independent of the oxygen content in the expiration air. Leakages are compensated to maintain proper breathing. The lung controlled amount of equalizing air prevents the possibility of hazardous outflow in case of leakages. The switchable connection is maintained between the compressed air line and the lung control valve with the oxygen line to ensure the supply of proper circulating air even in a failure of the electrical control of the oxygen supply. For the ratio of the two pressure gas supplies to each other it was expedient to select a ratio of air to oxygen of about 1:4. For a 2 hour apparatus, a 1.2 liter bottle with 200 bar filling pressure can be selected for the compressed oxygen, so that an oxygen supply of 240 liters is obtained, and a content of 0.3 liters at 200 bar can be selected for the compressed air bottle, which yields an air supply of 60 liters. The total breathing gas supply is then 300 liters which is sufficient for an operating time of 2 hours. |
