Air flow control damper with linear performance characteristics comprising an air foil control blade and inner annular orifice

Abstract

An air flow control damper consisting of either a tubular or rectangular casing, an internal annular orifice and within the orifice a rotatable circular or rectangular blade with an air foil profile. The blade may be either single or multi-part. The air flow control blade is designed to rotate on a shaft from an open position to a closed position modulating the air flowing through the casing. This damper exhibits a very low pressure drop—important for energy conservation—and a linear hystersis free performance curve—important when maintaining pressures in critical spaces.

1 . In an air flow control valve comprising outer casing, an inner annular orifice and a cooperating flat air control blade fixed to a rotating shaft. The annular ring provides sufficient space that the air passing through the casing will minimally impact the inner surface of the casing. 
     
     
         2 . the instant invention as described in  claim 1  combined with a perforated inner casing and an additional exterior solid exterior casing and with a sound attenuating material enclosed within the void between the inner and exterior casings. 
     
     
         3 . the instant invention as described in  claim 1  manufactured in various shapes to efficiently fit the installation including round, oval, square and rectangular. 
     
     
         4 . in the instant invention as described in  claim 1  the installation of two static pressure taps on either side and in close proximity to the orifice. The two pressure taps will measure the pressure drop across the office which is proportional to the flow through the damper. 
     
     
         5 . In an air flow control valve comprising an outer casing, an inner annular orifice and a cooperating air foil shaped air control blade fixed to a rotating shaft. The annular orifice provides sufficient space that the air passing through the casing the air will minimally impact the inner surfaces of the casing. 
     
     
         6 . The instant invention as described in  claim 5  combined with a perforated inner casing and an additional exterior solid exterior casing and with a sound attenuating material enclosed within the void between the inner and outer casings. 
     
     
         7 . the instant invention as described in  claim 5  manufactured in various shapes to efficiently fit an installation including round, oval square and rectangular 
     
     
         8 . in the instant invention as described in  claim 5  the installation of two static pressure taps on either side and in close proximity to the orifice which will measure the pressure drop across the office which is proportional to the flow through the damper. 
     
     
         9 . In an air flow control valve comprising an outer casing, an inner annular orifice and a cooperating multi part air foil shaped air control blade. Each part of the multi part blade may have equal or unequal areas and are fixed to one or more rotating shafts. The inner annular orifice provides sufficient space that the air passing through the casing the air will not impact the surfaces of the casing. 
     
     
         10 . the instant invention as described in  claim 9  combined with a perforated inner casing and an additional exterior solid exterior casing and with a sound attenuating material enclosed within the void between the two casings 
     
     
         11 . in the instant invention as described in  claim 9  the installation of two static pressure taps on either side and in close proximity to the orifice which will measure the pressure drop across the orifice which is proportional to the flow through the damper. 
     
     
         12 . the instant invention as described in  claim 9  manufactured is various shapes to efficiently fit the installation including round, oval square and rectangular