Mining Program Area: Fire Prevention and Control
Mine fires are a significant hazard to the safety and health of mine workers. On January 19, 2006, an underground mine conveyor belt fire occurred at the Aracoma Alma No. 1 mine located in Logan County, West Virginia. Two mine workers were fatally injured when they became separated from their crew while trying to escape from the fire. From 1990 through 2001, there were 1,060 fires, resulting in 560 injuries and 6 fatalities at U.S. mining operations. Most mine fires occurred in underground mines. Fire in an underground coal mine is especially hazardous because of the confined space, possible effects on the ventilation system, and limited and long evacuation routes. Mine fires also produce high levels of smoke and toxic gases, which can be detrimental to the health and safety of mine workers. Because many new combustible materials with new formulations have been introduced into the mining industry over the past twenty years, the potential hazard of combustion product toxicity poses a real threat to the safety and health of mine workers.
The purpose of the Office of Mine Safety and Health Research's (OMSHR) fire prevention and control program is to reduce the risk of mine fires through the development of new or improved strategies and technologies for mine fire prevention, detection, control, and suppression. To achieve the objective, OMSHR conducts research to:
- assess and predict the flammability and fire hazards of various combustible materials used in the mining industry;
- evaluate different sensors for reliable and early detection of mine fires;
- develop a real-time mine fire simulator that is capable of responding to mine fire sensor data and known ventilation conditions and then recommend actions to reduce the hazard of toxic smoke and the associated low visibility for mine worker escape;
- evaluate different fire suppression and extinguishment systems used in U.S. mines and provide guidelines for installation; and
- investigate the interaction between mine fires and the mine ventilation system using computational fluid dynamics (CFD) modeling and ventilation network simulation.
The research outcomes can be used in the promulgation of new mine safety regulations and for better mine fire detection and suppression systems, leading to a decrease in mine fires and better mine worker protection.
The unique facilities at OMSHR permit much of the mine fire research to be conducted under realistic, full-scale conditions. These facilities include the Safety Research Coal Mine and the Fire Suppression Facility at Lake Lynn Laboratory. OMSHR's current fire prevention and control research conducts laboratory experiments, full-scale fire tests, CFD modeling, and network simulations to address different mine fire issues.
Major areas of focus include:
- Properties of combustible mine materials relevant to fire safety:
Assess the overall fire hazard of combustible mine materials by studying and quantifying the properties that are most important to ignition, flaming, flame spread, and the production of toxic gases and smoke.
- Impact of fires on mine atmospheres and atmospheric monitoring systems:
Evaluate the impact of both fire size and fires of different combustibles on underground ventilated mine atmospheres and use this information to develop improved and interactive atmospheric monitoring systems.
- Reliable prediction of flame spread and smoke transfer in a mine ventilation system:
Validate improvements to the OMSHR mine fire simulation program, MFIRE 3.0, and develop more effective engineering designs for fire detection and suppression system installation through the use of the new MFIRE 3.0 code combined with CFD models.
- Engineered design of fire detection and suppression systems:
Obtain engineering data to develop guidelines for performance-based designs for mine fire detection and suppression system installation in conveyor belt entries and drive areas, stationary equipment, battery charging stations, and diesel fuel storage areas.
- Reducing spontaneous combustion hazards:
Use CFD modeling techniques to simulate the spontaneous heating of coals in longwall gob areas, and conduct CFD simulations to develop spontaneous combustion control methods and nitrogen injection strategies to prevent/suppress spontaneous heating in longwall gob areas.