Abstract: A chemical cartridge for respirators for respirators, the cartridge containing a chemical, e.g., potassium hyperoxide, which when acted upon by carbon dioxide and moisture, produces oxygen from a stream of inhaled air. Two discharge nozzles are provided which project into the chemical and out of which the regenerated exhaled air flows. The incoming flow occurs over a large area and the outflow occurs over a small area with the peripheral surfaces of the discharge nozzles being spaced substantially equidistant from an inlet surface of the chemical, thereby ensuring optimum use of the chemical for oxygen production purposes because a user's exhaled air is caused to flow completely through the entire space occupied by the chemical.

Abstract: A self-contained portable personal breathing apparatus that has a casing housing a canister containing an oxygen evolving chemical. The casing is disposed inside a cover which is disposed inside a bag. The cover and the casing form a thermal insulating pocket between them, and with the cover material and the casing material, also made of thermally insulating material, a triple layer of thermal insulation is formed around the canister to protect oxygen produced therein from the heat of reaction of the chemical in the canister. A heat exchanger is situated atop the canister to further cool oxygen before inhalation, and breathing tube extends from the bag to the user for channeling exhaled breath and oxygen.

Abstract: A closed cycle respirator includes a breathing bag, the bottom of which is in communication with a canister containing a chemical that binds carbon dioxide and water vapor and liberates oxygen. Inside the breathing bag there is a distributor that guides the regenerated respiratory air flowing up from the canister laterally in the direction of the breathing bag's side walls but keeps that air largely away from the side of the bag that lies against the chest of the wearer. The reason for directing the air through the bag in this manner is to reduce the temperature of the air before it is inhaled again.

Abstract: The outlets of an oxygen liberating canister and a carbon dioxide absorbing canister are connected with a breathing bag that has an outlet connected to an inhalation tube. An exhalation tube is connected with the canister inlets. A valve system controls the proportion of exhaled air flowing through each canister, from 100% to zero, the system being actuated by the breathing bag as the bag is inflated and deflated.