The Use of Cryogenic Air in Supplied Air Respiratory Protection

The Mine Improvement and New Emergency Response (MINER) Act of 2006 implemented new regulations in the underground coal mining industry that allow for the certification of non-compressed gas equipment for respiratory protection in underground coal mines. NASA’s Kennedy Space Center (KSC) Biomedical Research and Engineering Laboratory (BRL) is investigating the potential to expand cryogenic air supply systems into the mining and general industries. These investigations have, so far, resulted in four separate comparison and hardware development programs. The Propellant Handlers Ensemble (PHE) and Level “A” Ensemble Comparison (LAE): This study compared worker thermal stress while using the industry standard Level A hazardous material handling ensemble as opposed to using the similarly protective Propellant Handler’s Ensemble (PHE) that utilizes a cryogenic air supply pack, known as an Environmental Control Unit (ECU) as opposed to the compressed air Self Contained Breathing Apparatus (SCBA) used in the LAE. The research found that, in a 102°F environment, test subjects experienced significantly decreased body temperature increases, significantly decreased heart rate increases, and decreased sweat loss while performing a standard work routine while using the PHE, compared to the same test subjects performing the same routine while using the LAE. The Cryogenic Refuge Alternative Supply System (CryoRASS) project: The MINER Act of 2006 requires the operators of underground coal mines to provide refuge alternatives that can provide a safe atmosphere for workers for up to 96 hours in the event of a mine emergency. The CryoRASS project retrofitted an existing refuge chamber with a liquid air supply instead of the standard compressed air supply system and performed a 96 hour test. The CryoRASS system demonstrated that it provided a larger air supply in a significantly smaller footprint area, provided humidity and temperature control, and maintained acceptable oxygen and carbon dioxide levels in the chamber for the required amount of time. SCBA and Mine Rescue System (CryoBA/CryoASFS) Another requirement of the MINER Act is that additional emergency breathing equipment must be staged along evacuation routes to supplement the Self Contained/Self Rescue (SCSR) devices that are now required. The BRL has developed an SCBA known as the Cryogenic Breathing Apparatus (CryoBA), that has the ability to provide 2 hours of breathing air, a refill capability, and some cooling for the user. Cryogenic Air Storage and Filling Stations (CryoASFS) would be positioned in critical areas to extend evacuation time. The CryoASFS stations have a significantly smaller footprint and larger air storage capacity to similar compressed air systems. The CryoBA pack is currently undergoing NIOSH certification testing. Technical challenges associated with liquid breathing air systems: Research done by the BRL has also addressed three major technical challenges involved with the widespread use of liquid breathing air. The BRL developed a storage Dewar fitted with a Cryorefrigerator that has stored liquid air for four months with no appreciable oxygen enrichment due to differential evaporation. Testing of liquid breathing air was material and time intensive. A BRL contract developed a system that only required 1 liter of air and five minutes of time compared to the 10 liters of air and 75 minutes of time required by the old method. The BRL also developed a simple and cost effective method of manufacturing liquid air that joins a liquid oxygen tanker with a liquid nitrogen tanker through an orifice controlled “Y” fitting, mixing the two components, and depositing the mixed breathing air in a separate tanker.

The Acropolitan - v. 8, no. 3

In this issue...Doris Torongo, Montana Fossils, President Hoover, Mine Rescue, First Aid, Radio Debate, Anaconda Smelter, nickel-copper alloy, Ore Diggers basketball

The Amplifier - v. 4, no. 9

In this issue...Dej Tewtong, Civil Service Commision, Chess Club, Russian Submarines, Mine Rescue Training, Washoe Theatre, Anaconda, Montana

The Amplifier - v. 4, no. 11

In this issue...Mike Freebourn, seismograph, Mine Rescue course, Lydia's, Chess Club, Butte Daily Post, Butte Elks Lodge, State Board of Education, Gordon Parker

The Amplifier - v. 5, no. 9

In this issue...Engineering Days, Mine Rescue and First Aid, Chemistry Department, Mineral Club, Anderson-Carlisle Society, Honor Roll, Continental Oil Company, Intramural basketball

The Amplifier - v. 6, no. 8

In this issue...Miners hockey, SUB, M Club, Scandia Hall, Canyon Ferry Lake, Georgetown Lake, Orediggers, coffee shop, Metal's Bank, U.S. Mint, Mine Rescue and First Aid

The Amplifier - v. 7, no. 9

In this issue...Newman Club, Conoco, Petroleum Engineering, Marriage Lectures, Magma, Manuel Galup, Butte Mines, Glen Welch, Mountain View Church

The Amplifier - v. 8, no. 7

In this issue...Magma Yearbook, Marvin Senne, Continental Oil Company, NASA, Circle K Club, Mine Rescue training, Walter Mitty, International Club, Stu Stadler

The Amplifier - v. 9, no. 8

In this issue...Ceramic testing, Bob LeCoure, Butte Civic Center, Rotary Club, Saint Patrick's Day, First-Aid Class, Mine Rescue, Career Day, American Legion Baseball

The Amplifier - v. 11, no. 7

In this issue...KXLF TV, Mine Rescue, Talent Show, Linda Plubell, Gulf Oil Company, Student Loans, Theta Tau, Alaska, Newman Club

The Amplifier - v. 12, no. 7

In this issue...International Club, Easter Dance, Tiddledywinks, Mine Rescue, First Aid, Mineral Dressing, College Days, Circle K Club, Sigma Xi

The Amplifier - v. 13, no. 6

In this issue...Mine Rescue Training, Dr. Syntax, Engineers' Ball, Butte YMCA, Silver Bow Kiwanis Club, Kopper Kadets, Football, Sigma Xi, Montana Power Company

The Amplifier - v. 13, no. 7

In this issue...Chess Tournament, Suzie Foote, Mine Rescue Training, Vesta Scott, Liberal Arts, Montana Fish and Game, National Honor Society

The Amplifier - v. 14, no. 8

In this issue...College Days, International Club, Butte Kiwanis, Mine Rescue Training, First Aid Training, Kopper Kadets, Pentagon, Butte Symphony, Engagements, Weddings

Report on the Ermont Mine Sec. 35, T. 6 S., R. 11 W., Beaverhead County, Montana

An examination of the Ermont Mine was requested by the owners, Messrs. J. R. Bowles and R. B. Caswell, to determine the amount and grade of ore developed, the advisability of constructing a mill at the present time, and to recommend future development work.