Single-stage, multiple outlet centrifugal blower

Claim 1

A housing for a single-stage, multiple outlet centrifugal blower, comprising: a. a relatively stationary casing adapted to enclose a rotatable impeller, said casing having a generally planar barrier on the intake side of the impeller, a generally spiral plenum on the other side of the impeller, and means including a curvilinear wall for joining said plenum to the perimeter of said barrier; b. said barrier having a first port in a central region thereof to provide a fluid inlet in the vicinity of the eye of the impeller; c. said plenum having an exit section that provides a first fluid outlet from said casing and having an opening in its inboard side that extends along a predetermined limited portion of the periphery of the impeller; and d. a second fluid outlet comprising a second port in said barrier, said second port being located in a generally arcuate region of said barrier near the periphery of said impeller but displaced from said predetermined limited portion of the periphery so that said second port is out of register with said opening of said spiral plenum, the pressure and volume flow rate of fluid discharging through said second outlet being dependent on the shape and cross-sectional area of said second port and on the fluid backpressure on the discharge side of said second port and being substantially independent of the pressure and volume flow rate of fluid discharging through said first outlet, whereby the downstream backpressure of the fluid discharged from either one of said outlets will not significantly affect the flow of fluid discharging from the other outlet.