Patent ID: 8449250

Claim:
A direction changing duct ( 34 ) for changing a direction of flow of a fluid, the duct ( 34 ) comprising: a first duct section having an inlet ( 70 ) and a flow axis approximately along an axis defined as the X-axis, a second duct section having an outlet ( 72 ), a direction of flow at said outlet approximately along an axis defined as the Y-axis perpendicular to the X-axis, a flow direction changing segment connecting said first and second duct sections, wherein the flow direction changing segment includes an inward bulge ( 81 ) extending into the flow direction changing segment in the direction opposite to the direction of flow at said second duct section outlet, and outward bulges ( 170 , 171 ) perpendicular to the direction of flow of the first and second duct sections, wherein said inward bulge ( 81 ) extends inward at an apex ( 83 ) a distance (d 1 ) of from 0.1 to 0.6 times the diameter of the second duct outlet ( 72 ), said inward bulge measured along the Y-axis of a plane extending through the centerlines of the direction changing duct in the X/Y-axis, and measured in the direction opposite to the direction of flow at said second duct section outlet, and a smallest radius of from 0.5 to 2.0 times the diameter of the second duct outlet ( 72 ), and wherein said outward bulges ( 170 , 171 ) extend outward in a direction perpendicular to the X-axis and the Y-axis and defined as the Z-axis relative to the first duct section a distance (d 3 ) of from 0.5 to 2.0 times a diameter of the second duct outlet ( 72 ).