Assessment of the Efficiencies of Auxiliary Ventilation Systems Using Empirical Methods
CIM MineSpace 2001
Raymond S. Suglo, Ian R. Muirhead,
Increasing depths of mining coupled with the mechanization of most underground mining operations have led to growing complexities in the mine environments with the production of large amounts of gaseous and particulate contaminants. So there is the need to constantly assess and evaluate the performance of the existing mine ventilation systems to maintain safe and acceptable mine environmental conditions in workings to meet the requirements of federal, state or provincial laws. This paper uses the results of continuous monitoring of methane concentrations conducted in selected development headings in coal mines in North America to assess the effectiveness of existing auxiliary ventilation systems in the control of methane gas concentrations in the headings. The results show that the average quantities of fresh air required to dilute, disperse and remove methane concentrations within set levels of one minute varied from 5.43 m3/s in Heading #11 (Condition 2) to 27.97 m3/s in Heading #10 (Condition 1) and this represented about 12 to 26% of the quantities required to purge methane concentrations to safe levels within one minute under Condition 1 and 32 to 139% under Condition 2. The average purging times in the headings studied were less than 8 minutes, the forcing efficiencies of the auxiliary systems in the headings studied ranged from poor to excellent implying that the auxiliary ventilation systems were capable of controlling the methane concentrations below statutory levels but may not be able to cope with large and unusual methane makes in the headings. This study is important to avoid methane and coal dust explosions in coal mines that have claimed the lives of over 100,000 workers in the US and Canada since 1900.
Continuous Monitoring Systems, Efficient System Drivers, Safe Working Environment, Methane Gas Concentrations, Empirical Modeling, Auxialliary System Modeling, Mine ventilation