摘要 |
The breathing system includes an annular filtration unit having apertures opening radially through inner and outer walls thereof, a central passageway and filtration material between the walls. The filtration unit is disposed in a canister containing a hood, a mouthpiece, a closure and an annular filter in the annular space between the filtration unit and the wall of the canister. Upon removal of the closure, the hood and mouthpieces are deployed and the hood is drawn about an individual's head through an opening in the hood. With the mouthpiece in the individual's mouth, ambient air from a toxic gas or smoke-filled environment is drawn into the canister through the annular filter, and passes radially inwardly through the filtration unit into the central passageway, where the filtered air reverses direction for flow axially into the mouthpiece such that the individual may breathe filtered air. Exhaled air passes into the hood and out through the hood opening.
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