Mining Science and Technology, 13 (1991) 17-24 17 Elsevier Science Publishers B.V., Amsterdam The utilisation of air scoops for the improvement of ventilation in a coal mine heading Josua P. Meyer a Louis A. Le Grange a and Cor Meyer b Department of Mechanical Engineering Vaal Triangle Campus of the Potchefstroom University for CHE, P.O. Box 1174, Vanderbijlpark, 1900, South Africa b . . . . . Coal Mmmg Dwzswn, COMRO, P.O. Box 91230, Auckland Park, 2006, South Africa (Received September 19, 1990; accepted November 5, 1990) ABSTRACT Meyer, J.P., Le Grange, L.A. and Meyer, C., 1991. The utifization of air scoops for the improvement of ventilation in a coal mine heading. Min. Sci. Technol. 13: 17-24. Methane gas is emitted when coal is broken at the face of a coal mine. To prevent a situation where a methane gas explosion can occur, the face and heading must be ventilated effectively. In this paper an investigation is conducted to determine if the ventilation in the heading of a coal mine can be increased by the utilisation of air scoops. Two scoops are investigated, one upstream of the heading and one downstream of the heading. The influence of the air scoops on the flow field in the heading is determined numerically. The results show that based on penetration depth and absolute average air velocity, ventilation can be improved by the utilisation of air scoops and that it is better to locate these scoops downstream of the heading. Introduction During the underground mining of coal methane gas is emitted from the face of the heading as shown in Fig. 1. To prevent methane gas explosions in the heading, the gas must be removed rapidly. This is accom- plished by utilising air in the last through road for heading ventilation. Unfortunately the face where the methane gas is emitted is at the end of a heading which is difficult to ventilate effectively. Rapid removal of methane gas from the heading can occur only if air penetrates from the last through road to the face of the heading. Air and methane gas must mix and then the mixture must leave the heading. Air from the last through road circulates counter-clockwise in a recirculation zone in the heading if the air flow in the last through road is from left to right. The velocity distri- bution for such a case is similar to the classi- cal driven-cavity problem which has been FACE METHANE GAS HEADING I LAST THROUGH ROAD AIR Fig. 1. A schematic representation in plan view of the heading of an underground coal mine. 0167-9031/91/$03.50 © 1991 - Elsevier Science Publishers B.V.