The ASIA Miner - Reporting Important Issues to Mining Companies in the Asia Pacific Region
Issue link: http://asiaminer.epubxp.com/i/786114
VDMA 56 VDMA MINING SUPPLEMENT • 2017 The new Mine Refuge Chamber (MRC) 5000 attracted a lot of atten- tion at MINExpo last year. A total life support system, this cost-ef- fective chamber was completely designed by Dräger — from the seal-welded steel structure and redundant air supply system, to the soda lime cartridges and gas detection devices. "Because we design and build most of the individual compo- nents, we created a well-integrated, technically advanced life support system," said Brad Rekuc, sales manager, mining, for Dräger. "The MRC can be leased or purchased, and is totally supported by Dräger Service with local maintenance and repair to ensure that the chamber is always operational." Because every mine is different, Dräger also offers engineered chambers that are designed and built to custom- er-specific requirements. Several systems work together in the chamber to provide a safe breathing environment. The chamber can be connected to an external air supply. Oils, water and small particles are filtered from the air. A constant positive pressure of between 150 and 200 Pa in the chamber prevents contaminated air from entering the main room. This safe- ty feature is automatically sustained and controlled by the Dräger Breathing Protection Unit (BPU). Armed with positive pressure and a reliable air supply system, a gas-tight door prevents contaminated air from entering the cham- ber. The Dräger Airlock has an air purging system that dilutes any contaminated air that enters. This allows miners to enter and exit the chamber multiple times, while minimizing the risk of noxious gas and smoke entering the chamber. Dräger gas detection systems continually monitor the air inside the chamber, which allows miners to adjust the system depending on the values for carbon dioxide (CO 2 ) and oxygen (O 2 ). The chamber is a self-sufficient underground emergency chamber, meaning that it does not depend on external air or power supplies to keep miners safe. The air inside the chamber is regenerated by the CO 2 scrubbing process in the breathing air regeneration system. CO 2 is removed (scrubbed) from the interior air by easy-to-use Drägersorb soda lime cartridges, which eliminate direct contact with soda lime dust. Miners simply remove the caps, break the foil seals and insert the cartridges into the top of the BPU. This pour-free sce- nario eliminates the possibility of soda lime dust exposure in a small space. The BPU has a dedicated battery backup system, and each fan works independently and can be adjusted for the number of occu- pants. In self-sufficient operations, high-pressure cylinders replenish O 2 levels. Dräger's proprietary gas detection equipment continuously monitors the internal atmosphere for the presence of CO 2 and CO, as well as O 2 levels. If gas concentrations fall outside preset limits, audible and visual alarms warn the miners so they can adjust systems and maintain a safe atmosphere. An air conditioning system keeps the chamber's interior temperature and humidity at comfortable lev- els. In addition, a fixed external gas monitoring system that measures the CO and O 2 concentrations outside of the chamber and displays results inside the chamber can be installed as an option. The electrical system for the MRC 5000 includes batteries for all electrical functions, the air conditioning system, and green and red external status lights. Together with the inverter/charger system, bat- tery backup ensures continuous power for up to a minimum of 24 hours (extended times are optional). Health and Safety: A Safe Haven Underground The MRC 5000 is a self-sufficient underground emergency chamber.