Siebe Vitox

Siebe Gorman Vitox oxygen rebreather

Constant feed Oxygen rebreather

This apparatus is on the same regenerative principle as that of the “Proto”, but instead of being disposed equally back and front of the wearer, it is designed to be carried wholly on the back, with pressure gauge in front. A novel feature of the apparatus is the design of the CO₂ absorbent system, which consists of two metal chambers, charged with CO₂ absorbent, connected separately to the flexible breathing chamber. The wearer’s exhaled air passes through one absorbent chamber, in which the greater part of the CO₂ is absorbed, into the breathing chamber where it mixes with fresh oxygen, and thence on the wearer’s inspiratory effort, it is drawn through the second absorbent chamber which removes any residual CO₂.

Since less chemical action takes place in the second canister, the effect is to reduce the temperature of the inspired air appreciably. By this system, too, the use of shallower absorbent canisters is made possible, with the result that resistance to breathing is reduced. For work in high temperatures, a cooler is attached to the apparatus, in which case the CO₂ absorbent chamber on the expiratory side is of a somewhat larger size, while the chamber on the inspiratory side is smaller, the cooler being connected to the exit side of the latter chamber, as shown above. The case enclosing the apparatus is fitted with a pair of hinged doors or with a removable cover. In certain cases, e.g., where the apparatus is to be used under water, the CO₂ absorbent containers are fitted inside the breathing bag. The “Vitox” CO₂ absorbent canisters are emptied after use, and then recharged, ready for future use.

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