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US5338254A Expired / Lapsed US ⏱️ 0.0 years remaining

Increasing jet entrainment, mixing and spreading

Assignee: Midwest Research Institute
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Filing: 1992-12-22
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Granted: 1994-08-16
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Expires: 2012-12-22
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Abstract

Abstract A free jet of air is disturbed at a frequency that substantially matches natural turbulences in the free jet to increase the entrainment, mixing, and spreading of air by the free jet, for example in a room or other enclosure. The disturbances are created by pulsing the flow of air that creates the free jet at the desired frequency. Such pulsing of the flow of air can be accomplished by sequentially occluding and opening a duct that confines and directs the flow of air, such as by rotating a disk on an axis transverse to the flow of air in the duct.

Inventors

  • 👤 Robert B. Farrington

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 15:54
CPC Classifications
F; F24; F24F; F24F13/00; F24F13/02; F24F13/06; F24F13/072

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 74 words
A method for increasing the spreading, entrainment and mixing of an air flow that is expelled from a plenum into an enclosure with ambient air in the enclosure, including the step of imparting periodic pressure pulsations to the air in the plenum so that the frequency of the pulsations match a natural characteristic frequency of a turbulence in the air flow as the air flow is expelled into the ambient air in the enclosure.
Claim 2
Independent Claim 74 words
A method for increasing the spreading, entrainment and mixing of an air flow that is expelled from a plenum into an enclosure with ambient air in the enclosure, including the step of imparting periodic pressure pulsations to the air in the plenum so that the frequency of the pulsations match a natural characteristic frequency of a turbulence in the air flow as the air flow is expelled into the ambient air in the enclosure.
Claim 3
Dependent Claim 41 words
The method of claim 1, including the step of matching the frequency of the pulsations with a natural characteristic frequency of vortices occurring sequentially in the air flow as the air flow is expelled into the ambient air in the enclosure.
Claim 4
Dependent Claim 53 words
The method of claim 2, including the steps of measuring amplitudes of turbulence in the air flow as the air flow is expelled into the ambient air in the enclosure, and varying the rate of the pulsations in the air flow until the measured amplitudes of turbulence in the air flow is maximum.
Claim 5
Dependent Claim 26 words
The method of claim 2, including the steps of measuring the frequency of the vortices produced, and pulsating the air flow at about the same frequency.
Claim 6
Dependent Claim 37 words
The method of claim 2, including the steps of determining the natural characteristic frequency of the vortices produced, and pulsating the air flow at a frequency that is a multiple or fraction of said natural characteristic frequency.
Claim 7
Dependent Claim 42 words
The method of claim 1, including the steps of imparting periodic pressure pulsations to the air flow by directing the air flow through a confined flow path before expelling the air into said enclosure, and sequentially occluding and opening the flow path.
Claim 8
Dependent Claim 40 words
The method of claim 6, including the steps of positioning a disk in the confined flow path in an orientation such that it occludes the flow path in a first position and opens the flow path in a second position.
Claim 9
Dependent Claim 48 words
The method of claim 7, including the steps of mounting the disk on a rotatable axle in such a manner that the disk is rotatable repeatedly about an axis defined by said shaft through said first position and said second position, and rotating said disk about said axis.
Claim 10
Dependent Claim 211 words
Air distribution apparatus for injecting fresh air into an enclosure containing ambient air, comprising: a source of fresh air under a higher pressure than the ambient air in the enclosure; conduit means extending from said source to said enclosure for confining and directing a flow of the fresh air from said source to said enclosure; and pulsator means positioned in the flow of the fresh air between said source and said enclosure for imparting a pulsating variation in pressure in said flow of the fresh air, wherein said pulsator means includes a valve housing for confining the flow of fresh air in a direction that defines a flow axis, and gate means position in said valve housing for sequentially occluding and opening said valve housing to the flow of said fresh air, said gate means including a disk mounted rotatably in said valve housing in a manner that defines an axis of rotation that extends diametrically through said disk and transversely through said valve housing perpendicular to said flow axis, said disk being rotatable about said axis of rotation between a first position that occludes said valve housing to the flow of fresh air and a second position that is open to the flow of fresh air through the valve body.
Claim 11
Dependent Claim 211 words
Air distribution apparatus for injecting fresh air into an enclosure containing ambient air, comprising: a source of fresh air under a higher pressure than the ambient air in the enclosure; conduit means extending from said source to said enclosure for confining and directing a flow of the fresh air from said source to said enclosure; and pulsator means positioned in the flow of the fresh air between said source and said enclosure for imparting a pulsating variation in pressure in said flow of the fresh air, wherein said pulsator means includes a valve housing for confining the flow of fresh air in a direction that defines a flow axis, and gate means position in said valve housing for sequentially occluding and opening said valve housing to the flow of said fresh air, said gate means including a disk mounted rotatably in said valve housing in a manner that defines an axis of rotation that extends diametrically through said disk and transversely through said valve housing perpendicular to said flow axis, said disk being rotatable about said axis of rotation between a first position that occludes said valve housing to the flow of fresh air and a second position that is open to the flow of fresh air through the valve body.
Claim 12
Dependent Claim 26 words
The air distribution system of claim 9, including drive means connected to said disk for rotating said disk between said first position and said second position.
Claim 13
Dependent Claim 25 words
The air distribution system of claim 10, including speed control means connected to said drive means for varying the speed of rotation of said disk.
Claim 14
Dependent Claim 24 words
The air distribution system of claim 9, wherein said conduit means includes nozzle means for injecting said flow of fresh air into said enclosure.
Claim 15
Dependent Claim 40 words
The air distribution system of claim 12, wherein said conduit means includes an enlarged plenum positioned in said conduit means immediately upstream of said nozzle means for equalizing distribution of the flow of fresh air uniformly through the nozzle means.
Claim 16
Dependent Claim 23 words
The air distribution system of claim 13, wherein said pulsator means is positioned upstream of said plenum in said flow of fresh air.
Claim 17
Dependent Claim 22 words
The air distribution system of claim 12, wherein said nozzle means includes a narrow, elongated opening from said plenum into said enclosure.
Claim 18
Independent Claim 44 words
A method of exciting a free jet of fluid that has natural turbulences at periodic frequencies after the fluid flows through and exits a duct, comprising the step of disturbing said fluid at a frequency that substantially matches a natural frequency of said turbulences.
Claim 19
Independent Claim 44 words
A method of exciting a free jet of fluid that has natural turbulences at periodic frequencies after the fluid flows through and exits a duct, comprising the step of disturbing said fluid at a frequency that substantially matches a natural frequency of said turbulences.
Claim 20
Dependent Claim 31 words
The method according to claim 16, including the steps of creating large amplitude disturbances in said fluid by periodically pulsing said flow of fluid in said duct at said natural frequency.
Claim 21
Dependent Claim 24 words
The method of claim 5, including the step of pulsating the air at a frequency in the range of about 2 to 56 hertz.

References Cited (Backward Citations)

US681215A Cited
US2212468A Cited
US2972358A Cited
US3242846A Cited
US3815485A Cited
US3777651A Cited
US3927827A Cited
US4413550A Cited
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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-08-15 1998-02-14 1998-08-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-08-15 2002-02-14 2002-08-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-08-15 2006-02-14 2006-08-16 $7700.00 Window Closed / Lapsed

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