Patent ID: 7331759

Claim:
A drying fan comprising a fan hub rotational about an axis and having a plurality of fan blades extending radially therefrom for moving air along an axial flow direction from upstream to downstream upon rotation of said hub, said hub being mounted in a shrouded housing having an axial flow path therethrough, said housing having an intake cowling receiving intake air, and an exhaust cowling discharging exhaust air, said exhaust cowling having a tapered ramp both a) expanding the airflow and b) directing the airflow where desired, wherein said exhaust cowling has a downstream end having an outlet face of noncircular shape of variable radius from said rotational axis, wherein said outlet face is defined by an inner perimeter and an outer perimeter at said downstream end of said exhaust cowling, each of said perimeters having a perimeter corner at said tapered ramp, namely an inner perimeter corner at said tapered ramp, and an outer perimeter corner at said tapered ramp, wherein said inner perimeter has first and second straight sides meeting at said inner perimeter corner.