Coal Mine Fire

Coal Seam Fires

Every year, coal mine fires cause large scale environmental and economic devastation around the world. These fires are especially hazardous because the continuous burning underground can later re-ignite brush and forest fires where the coal seams naturally resurface. The reoccurring onset of coal mine fires continues to be one of the most perpetual problems facing the mining industry. The most unfavorable catastrophic result is that global coal fire emissions are estimated to include 40 tons of mercury going into the atmosphere annually, and three percent of the world's annual CO2 emissions.

How we can help put out coal mine fires

By injecting nitrified foam via boreholes, a fire barrier is applied through evaporation of entrapped water and cools the fire by energy extraction. Foam envelopes the burning coal and isolates it from oxygen. As the foam is absorbed, water is expelled and the temperature of the trapped water is raised by absorbing thermal heat and ultimately converts the water into steam. Water is extracted from foam either through collapsing bubbles or through the consequence of gravity yielding the bubble walls. Because this action is time dependent, foam can act as tiny fluid reservoirs, expelling water at a given rate that allows convergence onto the burning coal source, rather than rapidly running across the surface and away from the affected area. Omni’s on site generated nitrogen is an inert gas that serves as a purging agent to displace oxygen from the fire source, thus removing the fire’s energy source.

The Magic of Foam

Foam concentrate, water and nitrogen flow rates can be adjusted to produce several different characteristics and viscosities of foam. Consistencies range from very light to very thick foam, also known as stiff foam, with similarities of shaving cream. In addition, the mixture being introduced into the boreholes can be changed at any time from nitrogen foam to nitrogen only.

Nitrogen membrane vs. Liquid nitrogen

The N2 foam and nitrogen production unit combination is the most efficient and advantageous system available for fighting coal mine fires because it can be readily moved from one borehole location to another by using standard trucks. Bulk liquid nitrogen trucks can deliver more nitrogen in a unit of time but their use is limited by logistics complications and rugged road conditions. Every second counts in a coal fire. Human lives, property damage and the environment should never be left to the inherent limitations of cryogenic nitrogen transportation. Omni Compressed Air, Ltd. can supply on site nitrogen generating systems to help you fight your coal mine fire.