Abstract: A ventilation overcast comprises a frame member that defines a structure having a substantially inverted U-shape with first and second opposed side wall portions and a roof portion. A curtain member having a plurality of longitudinal corrugations therein is positioned adjacent the frame member so that a bottom portion of the curtain member contacts the floor of the mine. The longitudinal corrugations allow the curtain member to be crushed when subjected to floor heave.

Abstract: A dust suppression system for suppressing dust associated with a movement of dust producing material along an open conduit may include a hood assembly positioned adjacent the open conduit so that the hood assembly defines an interior chamber that is exposed to the dust producing material contained within the open conduit. A baffle member mounted to the hood assembly divides the interior chamber into an inlet chamber and an outlet chamber. A venturi assembly having an inlet end and an outlet end is mounted to the baffle member so that the inlet end of the venturi assembly is exposed to the inlet chamber and so that the outlet end of the venturi assembly is exposed to the outlet chamber. A pressurized fluid provided to the venturi assembly causes the venturi assembly to pull dust laden air contained within the inlet chamber to the outlet chamber, the fluid combining with a portion of the dust suspended in the dust laden air to suppress a release of dust into a surrounding atmosphere.

Abstract: A ventilation overcast may comprise a plurality of support columns, each of which has an upper end and a lower end. A plurality of cross beams are connected between the upper ends of each of the plurality of support columns so that the support columns and cross beams define a generally rectangular structure having two opposed side wall portions and a roof portion. A curtain member having a plurality of longitudinal corrugations therein is positioned between the lower ends of adjacent support columns located on the same side wall portion of the ventilation overcast so that a bottom portion of the curtain member contacts the floor of the mine. The longitudinal corrugations allow the curtain member to be crushed when subjected to floor heave.