Monitoring and Control of Ventilation to Improve Work Safety in Mines

Methane and fire hazards have a vital effect on work safety and continuity of mining operation. In the nineties, the SMP hazards monitoring and ventilation control systems, based on on-line measurement of air parameters, were put into operation at nearly 30 Polish mines. These systems provide continuous measurement of methane concentration in the range of 0-100% with automatic switching-off electrical energy immediately after detection of explosion danger. Early detection of coal self-heating and open fire is done by continuous measurements of CO, smoke, and oxygen content in mine air and temperature changes in air and in rock mass. Abnormalities and critical states are signalled to the Mine Dispatcher who activate the alarm and put the emergency procedures into motion immediately. The computer-based monitoring and control of ventilation performs the function of an expert system for fire detection and underground fire fighting. The mine dispatcher makes use of escape routes schemes and procedures of safe withdrawal of miners from endangered areas recorded in the computer memory. Besides, at important points the dispatcher can activate intrinsically safe alarm signalling units and the transparent programmed messages indicating the escape routes. Recently the control system of air distribution and energy-saving control of fans’ rotational speed by thyristor cascade has been carried out to adapt the parameters to real requirements during modernisation and closing of Polish coal mines. This paper describes the ways to improve safety and reduce the consumption of power used for ventilation in Polish coal mines.