Speaker
Description
Since 2018, NASA and the National Institute for Occupational Safety and Health (NIOSH) have been developing a liquid oxygen storage module (LOXSM) based upon the NASA patent-pending cryogenic flux capacitor (CFC) technology. The LOXSM is aimed at potentially replacing the gaseous or chemical-based oxygen supply used in current closed-circuit escape respirators (CCERs)—devices that must be carried on the person, ready to be quickly deployed and used for escape in an emergency, particularly in underground mining applications—with the primary goal being to reduce the size of a CCER device compared to current devices. By virtue of the core CFC functionality, cryogenic oxygen stored within the LOXSM will be released in response to a heat input ideally from the breathing loop of the CCER. Prior efforts focused on the oxygen storage potential of silica aerogel materials that the CFC utilizes and have been previously reported. Work then continued to explore the LOXSM’s potential to retain the CO2 in the breathing air stream produced by the user when using the CCER. The work presented here describes the extensive test program for determining the CO2 retention potential of a LOXSM for use in a CCER, as well as the design evolution of LOXSM prototypes in response to the testing. The removal of CO2 from the breathing air stream by a gas to liquid phase change creates a synergy that may be exploited to reduce or eliminate the required chemical CO2 absorber material used in current CCERs. Testing has shown that it is indeed possible to completely remove CO2 out of an effluent stream at the flowrate required for the capacity of the CCER for an appreciable time, and that the LOXSM prototype design progression had a positive effect on that time.
