Patent ID: 7293314

Claim:
A turbine drive apparatus comprising: a housing defining a passageway extending between an inlet and an outlet; said inlet comprising an orifice extending between spaced first and second surfaces of a plate and bounded by a peripheral edge formed by said plate; said peripheral edge defining a physical cross section area A 1 ; means for applying suction to said outlet for pulling a fluid stream into said passageway past said peripheral edge and forming a vena contracta defining a stream cross section area A 2 downstream from said edge, where A 1 >A 2 ; a turbine having blades mounted in said passageway proximate to said vena contracta; and wherein said peripheral edge defines a diameter D 1 and said vena contracta occurs at 1.5 times D 1 downstream from said orifice; and wherein said turbine blades are mounted in said passageway at a location 1.5 times D 1 downstream from said orifice.