Reverse performance characteristics of main fans in an oil shale mine

This paper gives the results of a study conducted to establish main mine fan reverse characteristics under laboratory and field conditions. Laboratory tests were performed using a 2.4-m (96-in) diam vane axial fan to establish the forward and reverse performance characteristics under controlled conditions. Subsequently, a field test was conducted in a Colorado oil shale mine during which two 2-m 79-in) diam fans were reversed. The data obtained indicate that reverse performance characteristics depend on the blade angle and the hub-to-tip ratio. The quantity in the reverse mode ranged from 30 to 65 pct less than in the forward mode, and the static pressure was directly proportional to the square of the quantity.