ABSTRACT
Board and pillar headings are typically ventilated with the use of freestanding fans. Polish copper mines are using this method of ventilation with great success. Fans are typically installed at the inlet to the heading or a drift. In order to restrict the air re-circulation, the fans are installed on the side of air inflow in the heading. The ventilation efficiency depends on the range of air stream produced by the fan and its assessment procedure can be based on the existing distribution of parameters, such as airflow velocity, air temperature or concentration of hazardous gases. Other determinants of the air stream range include the initial parameters of the air flow, such as initial flow velocity, the scale of turbulence and diameter of the diffuser. The shape of the developed velocity field depends to a large extent on the fan location in the cross-profile of the heading.
