VENTILATION Secondary or Panel Airways

Secondary or Panel Airways

There is a tendency for development panels to be mined for longer distances, in order to maximize the length of longwall panels, without increasing the number of headings. At the same time production rates from longwall equipment have increased. The result, combined with increasing face lengths, is ever more arduous ventilation requirements and high ventilation pressures as noted previously.
Airways around longwall face ends are also frequently obstructed by equipment, windrows of coal, brattice wings and secondary support all of which hinders air flow.
Flows and pressures at regulators can be very high and provision must be made in some cases to allow the safe passage of personnel through these devices (e.g. an enclosed steel tunnel with air lock to one side of the roadway).