Breathing apparatus, and method for controlling temperature fluctuations

摘要

A wearable breathing apparatus includes a thermal capacitor that a user inhales and exhales through. Inhaled air is cooled as it passes through the thermal capacitor, and exhaled air cools the material of the thermal capacitor for the next breathing cycle. The breathing apparatus may be used by a firefighter, for example, as a lightweight apparatus to enable the firefighter to safely breathe dangerously heated air, for example while in a fire shelter, that may otherwise cause injury to the user. The breathing apparatus advantageously does not require external power for cooling. The thermal capacitor may also be used as a part of a rebreather that uses a scrubber that removes carbon dioxide from exhaled air, for rebreathing. Further, the thermal capacitor may be used for other purposes, such as in recirculation of building air.

主权项

1. A wearable breathing apparatus for controlling temperature of air inhaled by a user, the breathing apparatus comprising:
a respiratory conduit that is adapted for the user of the apparatus to inhale and exhale through; and a thermal capacitor operatively connected to the respiratory conduit; wherein the thermal capacitor and the respiratory conduit are adapted such that inhaled air and exhaled air passing through the respiratory conduit also passes through a porous material of the thermal capacitor; wherein the porous material has a time constant, a lumped thermal capacitance of the porous material (mass of the porous material multiplied by specific heat of the porous material) multiplied by a thermal resistance of the porous material (the reciprocal of the heat transfer coefficient multiplied by the surface area available for heat transfer), that is at least 0.5 seconds; wherein the respirator conduit includes one or both of a mask configured to be placed over a mouth and a nose of the user, and a mouthpiece adapted to be placed in the mouth of the user; wherein the thermal capacitor includes a casing, external of the one or both of the mask and the mouthpiece, that surrounds the porous material; wherein the porous material includes one or more of a woven material, a mesh material, a bed of spheres, particles, and/or pellets, and/or a monolith; and wherein the porous material has a void fraction of at least 0.3.