Speaker
Description
In the event of an underground mine emergency that makes the ambient air irrespirable, mineworkers need to use Self-Contained Breathing Apparatus (SCBA) for escaping or to be rescued, and if trapped, be provided with breathable air to sustain life in shelters termed Refuge Alternatives. NIOSH explored cryogenic technologies for these applications and with the help of NASA built Cryogenic Breathing Apparatuses (CryoBA) for continued escape, Air Storage and Filling Stations (CryoASFS) for refilling CryoBAs along the escape route, Refuge Alternative Storage Systems (CryoRASS) for life support and cooling and a Liquid Oxygen Kit (LOXK), for closed circuit long duration rescue breathing apparatuses. The prototypes developed are described in this presentation together with their design specifications. Two versions with single and twin dewars of the CryoBA, which are open-circuit SCBA were built with refilling capability via a CryoASFS while being worn on the user’s back. The CryoASFS and CryoRASS stored the cryogen in large dewars, preventing commodity loss before use by employing cryocoolers in their designs. The CryoRASS employs a delivery module that recirculates and adds breathing gas within and into the shelter, while providing cooling inside it including removing moisture. The prototypes functioned well and were demonstrated on the surface and underground. The cryogenic SCBA prototypes were shown to be capable of meeting performance standards for subsequent approval of production grade units for underground mine use in USA. One manufacturer has shown an interest towards producing the CryoBA and CryoRASS and getting the respective approvals.