Patent ID: 8622695

Claim:
A vane-axial fan which comprises: a fan housing which includes a fan inlet; a motor which is connected to the fan housing; an impeller which is removably connected to the motor, the impeller comprising an impeller hub, a number of impeller blades which extend radially outwardly from the impeller hub, an impeller leading edge, an impeller trailing edge and an impeller tip; the fan housing including an inlet shroud which is positioned over the impeller, the inlet shroud including an upstream end portion within which the fan inlet is formed and a downstream end portion which is removably connected to a separate portion of the fan housing; the inlet shroud further including a first section which extends axially from the upstream end portion to approximately the impeller leading edge, a second section which extends axially from the first section to approximately the impeller trailing edge, and a third section which extends axially from the second section to approximately the downstream end portion; wherein the second section comprises a configuration which conforms to the configuration of the impeller tip; wherein the third section comprises a radius which increases from approximately the upstream end of the third section to approximately the downstream end of the third section; wherein the second section comprises a radius which increases from approximately the upstream end of the second section to approximately the downstream end of the second section; and wherein the radius of the second section increases linearly from approximately the upstream end of the second section to approximately the downstream end of the second section.