Mining Contract: Development of Components for Breathing Escape Apparatus (DSOV/HMC/VHPC)
This objective of this research is to deliver working prototypes of docking/switch-over valves, hoods/masks with passive communication elements, and very high-pressure oxygen cylinders—all of which will be used in the next generation of escape breathing apparatus.
Contract Status & Impact
This contract is ongoing.
Following a catastrophic event, mine workers and rescue teams may be exposed to harmful gases in the mine atmosphere. Breathing air supplies (BAS) technologies are used to isolate the lungs from this atmosphere or provide refuge alternatives where the atmosphere is controlled. Breathing air supplies for underground mining refer to a range of devices and systems that offer respiratory protection to miners in the event of an emergency. Some examples of BAS are self-contained self-rescuers (SCSRs), closed-circuit oxygen breathing apparatus (CCBAs), and gas supplies for refuge alternatives. Advanced BAS technology could improve a mine worker’s chances of surviving a mine disaster.
Working prototypes are needed of (1) docking and switch-over valves (DSOVs) that will enable connection of two breathing apparatus to allow a seamless transfer from one device to the other, (2) hoods/masks with passive communication elements (HMCs) that will allow natural breathing through the nose and mouth, and (3) very high-pressure oxygen cylinders (VHPCs) to store and deliver pure oxygen to the user through the device. These components must be designed and developed with due consideration to ease of use, compact size, durability, and adaptability to the selected breathing apparatus.
DSOVs would enable connection of two breathing apparatus to allow for a seamless transfer by the user from one device to the other. Hoods and masks are easier to use than current self-contained self-rescuers (SCSRs) fitted with a bitepiece, allowing for natural breathing through the nose and mouth as opposed to breathing only through the mouth. HMCs also allow speech diaphragms to be incorporated, enabling the wearer to communicate verbally during escape, which is not possible in current SCSR designs. Finally, VHPCs are used in oxygen breathing apparatus such as SCSRs to store and deliver pure oxygen to the user through the device. Current oxygen cylinders are designed to 3,000 psi service pressure, but higher pressures are now achievable with new manufacturing techniques.
Under this contract, Carleton Technologies will produce a prototype DSOV, or prototype DSOVs of different designs, that is compact and easy to use in a mine emergency situation by minimally trained users. Carleton Technologies will also conduct research to determine the feasibility of developing one common hood/mask with a passive communication element (HMC) design for the selected MSHA-approved SCSRs and any NIOSH-approved self-contained breathing apparatus (SCBA). Carleton Technologies will produce a prototype HMC, or prototype HMCs of different designs, to demonstrate their functionality with selected SCSRs.
For both the DSOV and HMC research, the goal is to produce a technology demonstrator that could be incorporated into a breathing device able to meet the criteria set forth in CFR 42 part 84, "Approval of Respiratory Protective Devices." For the VHPC research, the goal is to design and produce, for a mining SCSR, two Department of Transportation cylinder designs certified to 10,000 psi working pressure and to contain oxygen volumes of 70 liters and 140 liters when expanded to standard ambient temperature and pressure.
As of 2014, the VHPCs and a prototype DSOV had been produced, and the report related to the HMC research was being prepared.