ANALYSIS OF METHANE DILUTION USING LOCAL EXHAUST VENTILATION ON FRONT DEVELOPMENT OF LABORATORY SCALE UNDERGROUND COAL MINES

• Main Author: Fajar Saputra, Muhammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/67851
• Institution: Institut Teknologi Bandung

Emissions of methane gas in underground coal are produced from scattered coal, the remaining left-behind seams, and other coal seams that are located above or below the mined coal. If the concentration of methane gas reaches 5% to 15% in the air, it can potentially cause an explosion. Therefore, it is necessary to maximize the dilution of methane gas by considering the factors that influence the process. This study aims to determine the decrease of methane gas concentration based on the value of the diffusion coefficient by constructing a 1:10 scale tunnel model with a cross-sectional model of 40 cm x 40 cm using a local exhaust ventilation system. The results of the methane gas dilution with variations in the distance from the duct to the face, and fan power indicate that the conditions at the closest duct and the highest fan power have the greatest diffusion coefficient values. This is due to the increasing turbulence of airflow conditions, which are marked by an increase in the Reynolds number. There are differences in the value of the Taylor diffusion coefficient in theory and laboratory tests due to the differences in the dimensions of the physical model and flow condition being tested. In addition, this study also generated the effect of the diffusion coefficient on the dilution time, i.e., the greater the diffusion coefficient, the faster the dilution process of methane gas.