Claims
- 1. An air distribution system comprising, in combination:
- A. a plenum including means for receiving outside air and means for receiving return air,
- B. input flow concentrator and integral silencer disposed within said plenum, said concentrator silencer including a concentrator input port coupled to said plenum and sidewalls establishing an airflow path from said concentrator input port to an output port, said airflow path being substantially symmetrical about an output axis said sidewalls including inner and outer path defining surfaces lined with acoustically absorbent material, said inner and outer path defining surfaces defining a substantially radial airflow path at a point between said plenum and said output port and defining a substantially axial airflow path at said output port, said inner path defining surface being substantially symmetrical about said output axis and extending along said output axis substantially across said concentrator input port,
- C. a fan having an input port coupled to said output port,
- wherein said plenum includes:
- means for partitioning said plenum into first and second regions, said second region enclosing said concentrator and silencer,
- damper means for permitting airflow from said first region to said second region, and
- wherein said means for receiving return air establishes an airflow path for said return air into said first region, and
- wherein said means for receiving outside air establishes an airflow path for said outside air into said second region, said outside air receiving means being positioned between said concentrator/silencer and said partition means, and said outside air receiving means including a tapered duct having a means for establishing an airflow path from the interior of said tapered duct to the portion of said second region between said tapered duct and said partition means.
- 2. A system according to claim 1 wherein said concentrator and silencing means include inner and outer sections coaxial with said airflow axis, said outer section being hollow and having a substantially conical inner surface and said inner section having a substantially conical outer surface, said inner and outer surfaces being mutually separated to form said path defining surfaces.
- 3. A system according to claim 2 wherein said flow path is characterized by a mean radius at the point coupling said plenum which is greater than the mean radius at said output port.
- 4. A system according to claim 3 wherein the boundaries of cross-sections of said flowpath defined by said inner and outer surfaces are circular.
- 5. A system according to claim 3 wherein the boundaries of cross-sections of said flowpath defined by said inner and outer surfaces are polygonal.
- 6. A system according to claim 1 wherein said fan is an axial fan having an input and output port, said fan input port being coupled to said output port of said flow concentrator means.
- 7. A system according to claim 6 wherein said concentrator and silencing means include inner and outer sections coaxial with said airflow axis, said outer section being hollow and having a substantially conical inner surface and said inner section having
- a substantially conical outer surface, said inner and outer surfaces being mutually separated to form said path defining surfaces.
- 8. A system according to claim 6 wherein each end of the drive shaft for said axial fan is coupled to a separate driving motor, said motors being characterized by different output speeds, and
- wherein said system further includes a control to selectively control said motors whereby only one is operative at a time.
- 9. A system according to claim 1 wherein said system further includes at least one silencer and branch take-off coupled to the output port of said fan.
- 10. A system according to claim 9 wherein said branch take-off and silencer comprises an apparatus for coupling an airstream from an input duct leading from said fan output port to an output duct and one or more branch ducts,
- said input and output ducts having a common central axis and similar cross-sectional shapes at the ends to be coupled and said input duct having a larger cross-sectional area than said output duct, and said branch ducts having branch axes at the end to be coupled to said input duct, said branch axes being angularly offset from said common central axis, said apparatus comprising:
- A. an outer section having a cross-section substantially the same as the cross-section of said input duct, said outer section having a central axis coaxial with said common axis and said outer section being coupled at one end to said end of said input duct,
- B. an inner section having a cross-section substantially the same as the cross-section of said output duct, said inner section having a central axis coaxial with said common axis, and said inner section being coupled at one end to said end of said output duct and extending into said outer section to define a shell region between said inner and outer sections,
- C. a plug means for sealing the end of said shell region adjacent to said output duct,
- D. channel means for establishing a plurality of channels in said shell region, said channels extending from a point near the end of said shell region adjacent to said input duct to an intermediate point within said shell region, whereby the portion of said shell region between said intermediate point and said plug means forms a common plenum,
- E. branch coupling means for coupling said plenum to said branch ducts.
- 11. A system according to claim 1 wherein said system includes
- a main duct coupled to said fan and a plurality of branch ducts, each of said branch ducts including means to tap a portion of the airstream from another of said ducts, wherein the remainder of said airstream in the tapped duct passes to an output duct, further comprising:
- distributed means for attenuating noise in one or more of said branch ducts, said distributed means including silencing means associated with each of said branch ducts, each of said silencing means being located at or near the junction of said associated branch duct with the tapped duct.
- 12. A system according to claim 11 wherein at least one of said tap means and said silencing means includes apparatus for coupling said airstream from said tapped duct to an input duct and channelling said tapped air to one or more branch ducts, wherein the remainder of the airstream in said tapped duct passes to an output duct,
- said input and output ducts having a common central axis and similar cross-sectional shapes at the ends to be coupled and
- said input duct having a larger cross-sectional area than said output duct, and said branch ducts having branch axes at the end to be coupled to said input duct, said branch axes being angularly offset from said common central axis, said apparatus comprising:
- A. an outer section having a cross-section substantially the same as the cross-section of said input duct, said outer section having a central axis coaxial with said common axis and said outer section being coupled at one end to said end of said input duct,
- B. an inner section having a cross-section substantially the same as the cross-section of said output duct, said inner section having a central axis coaxial with said common axis, and said inner section being coupled at one end to said end of said output duct and extending into said outer section to define a shell region between said inner and outer sections.
- C. a plug means for sealing the end of said shell region adjacent to said output duct,
- D. channel means for establishing a plurality of channels in said shell region, said channels extending from a point near the end of said shell region adjacent to said input duct to an intermediate point within said shell region, whereby the portion of said shell region between said intermediate point and said plug means forms a common plenum,
- E. branch coupling means for coupling said plenum to said branch ducts.
- 13. A system according to claim 9 wherein said branch take-off and silencer comprises apparatus for coupling an airstream from an end of an input duct leading from said fan output port to an end of an output duct and at least one branch duct, said apparatus comprising:
- A. an inner section having a cross-section substantially the same as the cross-section of the upstream end of said output duct, said inner section being adapted for coupling at one end to said upstream end of said output duct,
- B. an outer section disposed about at least a portion of said inner section and defining a shell region between said inner section portion and said outer section,
- C. channel means for establishing at least one channel in said shell region, said channel extending from a point near the end of said shell region adjacent to said input duct to the upstream end of said branch duct,
- D. branch coupling means for coupling said channel to said upstream end of said branch duct.
- 14. A system according to claim 11 wherein at least one of said tap means and said silencing means includes apparatus for coupling said airstream from said tapped duct to an input duct and channelling said tapped air to one or more branch ducts, wherein the remainder of the airstream in said tapped duct passes to an output duct, said apparatus comprising:
- A. an inner section having a cross-section substantially the same as the cross-section of the upstream end of said output duct, said inner section being adapted for coupling at one end to said upstream end of said output duct,
- B. an outer section disposed about at least a portion of said inner section and defining a shell region between said inner section portion and said outer section,
- C. channel means for establishing at least one channel in said shell region, said channel extending from a point near the end of said shell region adjacent to said input duct to the upstream end of said branch duct,
- D. branch coupling means for coupling said channel to said upstream end of said branch duct.
REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 944,134, filed on Sept. 20, 1978. That application is related to U.S. patent application entitled "Branch Take-Off And Silencer For An Air Distribution System", Ser. No. 944,133 filed on Sept. 20, 1978 which is now U.S. Pat. No. 4,182,430. The related application is incorporated by reference herein.
US Referenced Citations (6)
Foreign Referenced Citations (3)
Number |
Date |
Country |
715865 |
Aug 1965 |
CAX |
444206 |
Mar 1935 |
GBX |
1198549 |
Jul 1970 |
GBX |
Continuation in Parts (1)
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Number |
Date |
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Parent |
944134 |
Sep 1978 |
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