Estimating the effects of line brattice ventilation system variables in an empty heading in room and pillar mining using CFD
Journal of the Southern African Institute of Mining and Metallurgy
Auxiliary ventilation is required to ventilate development headings, which form part of the secondary circuit and are separate from the main flows. The design, selection, and installation of any auxiliary ventilation device requires an understanding of the capabilities of the equipment and the requirement in hand. Codes of practice and regulations in operating mines are developed based on this understanding. Ventilation engineers and mine managers use these codes and regulations to develop
... ons to develop plans for optimally managing the hazards presented by the mining operations and the environment. Using this approach, a line brattice (LB) can be an effective method for providing sufficient air into the development heading. A LB is a low-cost, short-term solution to direct The ventilation of underground coal mines plays an important role in minimizing the risk of methane and coal dust explosions. The ability of ventilation, with the use of line brattices (LBs), to remove methane and coal dust in empty headings is dependent on the amount of air leaving the LB and entering the heading. The quantity of this air depends on the associated system variables, namely heading dimensions, settings of the LB, and velocity of air in the last through road (LTR). However, the exact effect of these system variables on the flow rate at the exit of the LB in an empty heading is not known. The installation of LBs in South African coal mines is generally carried out based on experience. This can result in overor under-ventilation and may increase the cost of providing ventilation or cause accidents, respectively. In this paper, using computational fluid dynamics (CFD), the air flow rate at the exit of the LB in an empty heading was estimated using full-scale three-dimensional models. The CFD model used was validated using experimental results Firstly, the settings of these three system variables were varied, the flow rates at the exit of the LB were measured, and finally the results were used to calculate the effect of each system variable. The outcome is a mathematical formula that can be used to estimate air flow rate at the exit of the LB in empty headings for any practical scenario. This paper will help the coal mining sector in South Africa by providing estimation models based on scientific reasoning for the installation of LBs, and will also serve academia as part of the curriculum towards educating future mining engineers. ventilation, coal mines, line brattice, CFD.