Project Title:

Integrated Carbon Dioxide, Humidity, and Thermal Control for an EMU Gas Stream

12.07-7830
900937
Integrated Carbon Dioxide, Humidity, and Thermal Control for an EMU Gas Stream

Abstract:

An advanced absorbent has been identified for simultaneously removing carbon dioxide,
humidity, and heat from the gas stream in an Extravehicular Mobility Unite (EMU).
This absorbent eliminates several EMU components, reduces the size of others, and
minimizes the mass and volume of the EMU. It will not vaporize and is not toxic.
The system studied is completely closed and regenerable. No gases are vented during
or after the Extravehicular Activity (EVA). The system produces water and C02 at
1.0 atmosphere in separate streams. The heat sink capacity can be easily recharged.
Based on previous application of the absorbent, the chemicals and equipment have
the ability to operate several years without major repair or replacement. Based upon
practical component efficiencies, the advanced absorbent requires one-third the power
for regeneration of other advanced C02 control technologies including silver oxide.
The absorbent also provides cooling to the EMU gas stream during EVA. The cooling
capacity is restored by connection to a spacecraft cooling loop operating at 4oC
(40oF). No additional active refrigeration unit is needed to restore the heat absorption
capacity.
A regenerable portable breathing apparatus would be of use to fire fighters and mine
rescuers where there is a need to remove heat from the breathing gas stream. Due
to the ease of regeneration and low cost of the absorbent, the system could be used
by underwater divers (recreational and/or commercial) or personnel operating in a
contaminated air environment with lower cost than current closed-loop systems.
carbon dioxide absorbent, thermal control, humidity control