EP0961087A2 - Fan scroll - Google Patents

Fan scroll Download PDF

Info

Publication number
EP0961087A2
EP0961087A2 EP99630038A EP99630038A EP0961087A2 EP 0961087 A2 EP0961087 A2 EP 0961087A2 EP 99630038 A EP99630038 A EP 99630038A EP 99630038 A EP99630038 A EP 99630038A EP 0961087 A2 EP0961087 A2 EP 0961087A2
Authority
EP
European Patent Office
Prior art keywords
flow path
fan
scroll
cutoff
blower
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP99630038A
Other languages
German (de)
French (fr)
Other versions
EP0961087A3 (en
EP0961087B1 (en
Inventor
Shau-Tak R. Chou
Mark A. Daniels
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Carrier Corp
Original Assignee
Carrier Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to US8446498P priority Critical
Priority to US84464 priority
Application filed by Carrier Corp filed Critical Carrier Corp
Publication of EP0961087A2 publication Critical patent/EP0961087A2/en
Publication of EP0961087A3 publication Critical patent/EP0961087A3/en
Application granted granted Critical
Publication of EP0961087B1 publication Critical patent/EP0961087B1/en
Anticipated expiration legal-status Critical
Application status is Expired - Fee Related legal-status Critical

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04DNON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00Details, component parts, or accessories
    • F04D29/40Casings; Connections of working fluid
    • F04D29/42Casings; Connections of working fluid for radial or helico-centrifugal pumps
    • F04D29/4206Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for elastic fluid pumps
    • F04D29/4226Fan casings
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24FAIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F13/00Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
    • F24F13/24Means for preventing or suppressing noise
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24FAIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F7/00Ventilation, e.g. by means of wall-ducts or systems using window or roof apertures
    • F24F7/007Ventilation, e.g. by means of wall-ducts or systems using window or roof apertures with forced flow
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24FAIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F13/00Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
    • F24F13/24Means for preventing or suppressing noise
    • F24F2013/247Active noise-suppression

Abstract

The angular extent of the flow path in a fan scroll is extended by reducing the rate of radial expansion of the flow path. By extending the angular as circumferential extent of the scroll flow path downstream of the fan impeller ANC structure can be located in/on the scroll while being located a sufficient distance downstream of the impeller. The flow path length can be increased without increasing the cubage of the scroll and, if desired, a further flow path increase can be achieved by a combination of the reduced rate of radial expansion together with increasing the cubage.

Description

  • To control the noise from air handling units (AHUs), duct active noise control (ANC) systems are starting to be employed in air distribution systems. An ANC system basically requires the sensing of the noise associated with the fan for distributing air, producing a noise canceling signal and determining the results of the canceling signal so as to provide a correction signal to the loudspeaker. There is a time delay associated with sensing the noise and producing a canceling signal. This time delay necessary for the canceling to take place equates to the distance in the system required between the reference, or input, noise sensor and the loudspeaker. Additional space is required between the loudspeaker and the error sensor which also equates to a distance in the system.
  • A centrifugal fan discharges into a scroll which provides an expanding flow path for the air passing from the impeller into the scroll. The flow path, typically, is expanding radially but may also be expanding axially. It is common to characterize a fan by the angle of the slope of a plot of the variable scroll radius (R) vs the angular or circumferential extent (r·), where r is the radius of the fan and  is the angular extent). In conventional designs, the annular extent of the flow path is less than 360°, with 300° being typical. The reasons for this angular extent is the diffusing of the air flow as well as minimizing the space and material needed to make the scroll.
  • The angular extent of a fan scroll flow path which is a radius vector from the fan hub to the scroll such that the radius vector is essentially perpendicular to the flow leaving the fan housing is extended beyond 360° by reducing the rate of radial expansion of the flow path. It will be noted that the increased angular extent of the scroll flow path is in the portion having the greatest radius. At a radius of two feet, a 30° angular or circumferential extent (r·) corresponds to approximately one foot. By extending the angular or circumferential extent of the scroll flow path downstream of the fan impeller and reducing the rate of expansion, the flow path length can be increased without increasing the size or cubage of the scroll or with a minimal increase thereof.
  • Additionally, length can be added within the scroll portion of the flow path by enlarging the size or cubage of the scroll. The significance of the increased flow path length is that it permits locating the ANC structure wholly within the extent of the scroll while being located a sufficient distance downstream of the impeller to avoid significant flow noise.
  • It is an object of this invention to integrate an active noise cancellation system into an air handler unit.
  • It is another object of this invention to reduce the size impact of active noise control devices by better integration of active noise control systems with blowers.
  • It is a further object of this invention to increase the flow path length within a fan scroll. These objects, and others as will become apparent hereinafter, are accomplished by the present invention.
  • Basically, the rate of expansion within a fan scroll is reduced such that a longer flow path within the scroll is necessary to achieve the desired expansion. The increased flow path length permits the integration of an ANC system with the air handler.
  • Figure 1 is a PRIOR ART air handler unit with a conventional duct ANC system;
  • Figure 2 is a view of a PRIOR ART fan scroll for the air handler unit of Figure 1;
  • Figure 3 is a graphical representation of the relationship between the scroll radius and the angular extent of the scroll for conventional α1 and the present invention's α2 scroll-expansion angles;
  • Figure 4 is a view of the fan scroll of the present invention; and
  • Figure 5 is a view of the fan scroll of Figure 4 modified to include structure of a duct ANC system.
  • In Figure 1, the numeral 10 generally designates a conventional AHU with conventional duct ANC structure located in duct 14 which is connected to the discharge of fan 12. The AHU 10 is typically made up of a plurality of sections and/or subassemblies including mixing box 10-1, filter 10-2, coil 10-3 and fan housing 10-4. Fan 12 has a cutoff 12-2 which defines the actual outlet from scroll 12-1 but, as is conventional, the outlet defined at the cutoff discharges into the larger duct 14. For maximum performance, expansion of the flow is allowed to take place in the duct 14 for a distance equal to three times the diameter of blower 12-3. In that distance the turbulence associated with the fan discharge diminishes along with the associated difficulties with locating sensing microphones 16 in a region where considerable flow generated noise is present. A typical duct ANC system for large air distribution systems can require a ten foot spacing to accommodate the input noise sensing microphones(s) 16, the noise canceling speaker(s) 18 and the error sensing microphone(s) 20.
  • In operation, blower 12-3 is driven by motor 13 thereby drawing return and makeup air into the AHU 10, through a heat exchanger defined by coil 10-3 to heat or cool the air and delivering the resultant conditioned air from scroll 12-1 into duct 14. The fan noises are sensed by microphone(s) 16 and through circuitry (not illustrated), speaker(s) 18 is (are) driven to produce a signal to cancel the fan noise. Microphone(s) 20 sense the result of the noise cancellation by speaker(s) 18 and through circuitry (not illustrated) the output of speaker(s) 18 is corrected such that sound energy is minimized at microphone(s) 20..
  • Referring specifically to Figure 2, as illustrated, the air is discharged from clockwise rotating blower 12-3 into the space 12-4 between blower 12-3 and scroll 12-1. The space 12-4 is of increasing cross sectional area in a clockwise direction such that the air is permitted to expand as it travels along space 12-4 towards the fan outlet 12-5. With cutoff 12-2 defining one end of the space 12-4 it will be noted that space 12-4 is less than 360° in extent. Blower 12-3 has a radius r and is spaced from cutoff 12-2 a distance d such that the radius, R, of scroll 12-1 is r+d at cutoff 12-2. The angular extent, , of scroll 12-1 is measured clockwise, as viewed in Figure 2, from cutoff 12-2 and, typically, is on the order of 300°. The radius R and space 12-4 increase with  in going clockwise from cutoff 12-2 towards fan outlet 12-5. The radius R increases to its maximum value Ro at the fan discharge.
  • Referring to Figure 3, r+d represents the radius R of scroll 12-1 at cutoff 12-2 or the radius of scroll 112-1 at cutoff 112-2. Angle α1 represents the expansion angle for scroll 12-1 and radius R reaches its maximum value, Ro, at Ro = (r+d) + r 1 tan α1. A typical value of 1 would be 300°. According to the teachings of the present invention, expansion angle α1 is reduced to α2 and, accordingly, Ro = (r+d) + r2 tan α2. A typical value of 2 would be 450° which would represent approximately a five foot increase of r 2 relative to r 1 for a two foot radius. A typical value of α2 would be from 4° to 10°. Note that while a scroll with a linear expansion is used for purposes of illustration, other expansions can be used.
  • In Figures 4 and 5, the numeral 112 designates the modified fan of the present invention. In fan 112, as compared to fan 12, the cutoff has been effectively shifted counterclockwise such that the rate of radial expansion, α2, of space 112-4 is less than the corresponding rate of radial expansion, α1, of space 12-4. Additionally, the angular extent  from the point of closest proximity between blower 112-3 and cutoff 112-2 and the outlet 112-5 is, as illustrated, on the order of 180° greater than that for fan 12 i.e.  is at least 400° but, preferably on the order of 480°. The present invention uses the increased circumferential extent to locate the ANC structure which is then sufficiently far along the flow path in the scroll 112-1. As noted above, the slow rate of expansion in scroll 112-1 as compared to scroll 12-1 provides a longer flow path within the same cubage. If the cubage is increased in combination with the slow rate of expansion, the flow path length can be further increased. Because the increased length is in the nature of a spiral, the portion of the flow path beyond 360° is radially separated from the upstream portion of the flow path rather than being axially separated. Accordingly, all or portions of the scroll flow path may be provided with an acoustic damping liner.
  • Referring specifically to Figure 5, it will be noted that sensing microphone(s) 16 is (are) located at a location, nominally, 360° along the flow path such that they are ahead of or directly opposite the fan cutoff 12-2. Sensing microphone(s) 16 can be located further upstream, e.g. 300° along the flow path since angular extent is only one component of the parameters dictating flow path length. Speakers 18 are located downstream of microphone(s) 16, as illustrated, nominally, 120° further along the flow path. Since the microphone 16 location can be varied, speakers 18 may also be moved upstream with 400° along the flow path being at the lower acceptable range. At a nominal two foot diameter the 120° translates into about four feet downstream of the microphone(s) 16. Microphone(s) 20 can be located downstream of the blower 112-3 in the duct (not illustrated) such that they are in the same plane or downstream of loudspeaker(s) 18. If necessary, or desired, the speaker(s) 18 can be located in the duct (not illustrated) while taking advantage of the space saving features associated with locating microphone(s) 16 in or on scroll 112-1.

Claims (8)

  1. A fan (112) having a housing;
    said housing (112-1) having an outlet (112-5);
    a blower (112-3) located in said housing;
    said housing having a radially increasing section surrounding said blower and defining a flow path therewith;
    a cutoff (112-2) located in said housing and coacting with said blower to define the closest radial separation between said blower and any surrounding structure;
    a flow path (112-4) defined between said blower and said radially increasing section starting at said cutoff and extending for at least 360° starting from said cutoff.
  2. The fan of claim 1 wherein said flow path is over 450° in extent.
  3. The fan of claim 1 further including means (16) for sensing noise located at a location at least 300° along said flow path.
  4. The fan of claim 3 further including means (18) for producing a noise canceling signal at a location at least 360° along said flow path.
  5. The fan of claim 4 wherein said flow path is over 450° in extent.
  6. The fan of claim 1 further including means (16) for sensing noise located nominally opposite of said cutoff.
  7. The fan of claim 6 further including means (18) for producing a noise canceling signal at a location at least 360° along said flow path.
  8. The fan of claim 7 wherein said flow path is over 450° in extent.
EP19990630038 1998-05-26 1999-04-16 Fan scroll Expired - Fee Related EP0961087B1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US8446498P true 1998-05-26 1998-05-26
US84464 1998-05-26

Publications (3)

Publication Number Publication Date
EP0961087A2 true EP0961087A2 (en) 1999-12-01
EP0961087A3 EP0961087A3 (en) 2003-01-08
EP0961087B1 EP0961087B1 (en) 2004-11-24

Family

ID=22185125

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19990630038 Expired - Fee Related EP0961087B1 (en) 1998-05-26 1999-04-16 Fan scroll

Country Status (3)

Country Link
EP (1) EP0961087B1 (en)
DE (1) DE69922083T2 (en)
ES (1) ES2230824T3 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1703139A1 (en) * 2005-03-14 2006-09-20 ebm-papst Landshut GmbH Centrifugal ventilator
WO2007062889A2 (en) * 2005-11-30 2007-06-07 Siemens Aktiengesellschaft Gas flow generator comprising a gas outlet and a noise reducer, and method for the reduction of noise
EP2594853A1 (en) 2011-11-21 2013-05-22 Ask Industries Societa' per Azioni A low-noise fume extractor hood.
US9508337B2 (en) 2013-05-17 2016-11-29 Ask Industries Societa Per Azioni Low-noise fume extractor hood

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4182596A (en) * 1978-02-16 1980-01-08 Carrier Corporation Discharge housing assembly for a vane axial fan
US5156524A (en) * 1990-10-26 1992-10-20 Airflow Research And Manufacturing Corporation Centrifugal fan with accumulating volute
WO1993002445A1 (en) * 1991-07-16 1993-02-04 Noise Cancellation Technologies, Inc. High efficiency fan with adaptive noise cancellation
US5279515A (en) * 1992-12-21 1994-01-18 American Standard Inc. Air handling unit with improved acoustical performance
EP0596846A1 (en) * 1992-11-03 1994-05-11 Aktiebolaget Electrolux Kitchen ventilator

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4182596A (en) * 1978-02-16 1980-01-08 Carrier Corporation Discharge housing assembly for a vane axial fan
US5156524A (en) * 1990-10-26 1992-10-20 Airflow Research And Manufacturing Corporation Centrifugal fan with accumulating volute
WO1993002445A1 (en) * 1991-07-16 1993-02-04 Noise Cancellation Technologies, Inc. High efficiency fan with adaptive noise cancellation
EP0596846A1 (en) * 1992-11-03 1994-05-11 Aktiebolaget Electrolux Kitchen ventilator
US5279515A (en) * 1992-12-21 1994-01-18 American Standard Inc. Air handling unit with improved acoustical performance

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1703139A1 (en) * 2005-03-14 2006-09-20 ebm-papst Landshut GmbH Centrifugal ventilator
WO2007062889A2 (en) * 2005-11-30 2007-06-07 Siemens Aktiengesellschaft Gas flow generator comprising a gas outlet and a noise reducer, and method for the reduction of noise
WO2007062889A3 (en) * 2005-11-30 2007-07-26 Robert Boesnecker Gas flow generator comprising a gas outlet and a noise reducer, and method for the reduction of noise
EP2594853A1 (en) 2011-11-21 2013-05-22 Ask Industries Societa' per Azioni A low-noise fume extractor hood.
US9508337B2 (en) 2013-05-17 2016-11-29 Ask Industries Societa Per Azioni Low-noise fume extractor hood

Also Published As

Publication number Publication date
DE69922083D1 (en) 2004-12-30
EP0961087B1 (en) 2004-11-24
DE69922083T2 (en) 2005-03-31
ES2230824T3 (en) 2005-05-01
EP0961087A3 (en) 2003-01-08

Similar Documents

Publication Publication Date Title
CA2412773C (en) In-line centrifugal fan
ES2380108T3 (en) centrifugal fan
US6178764B1 (en) Air conditioning system
RU2493497C2 (en) Internal unit of air conditioner and air conditioner
CA2216500C (en) Fan for air handling system
US20100187037A1 (en) Sound Absorbing Structure of Electronic Equipment
US6881031B2 (en) Centrifugal air blower
US7093589B2 (en) Apparatus for increasing induction air flow rate to a turbocharger
KR100405982B1 (en) Flow path structure for cassette typed air conditioner
CN1078317C (en) Multivane radial fan designing method and multivane radial fan
JP4185654B2 (en) Centrifugal multi-blade blower
KR100423116B1 (en) Air intake and blowing device
JP3140898B2 (en) Rectifying guide blower and suction panel as well as the device of the device
EP0862776A1 (en) Acoustic resonator
CA2152217C (en) Compact centrifugal fan
EP0780556B1 (en) Cooling air system for an engine
JP3268279B2 (en) Air conditioner
US5601400A (en) Centrifugal blower improved to reduce vibration and noise
JP2589945B2 (en) Impeller for horizontal fan
US5910045A (en) Air discharge unit for underfloor air conditioning and underfloor air conditioning system using same
US6896478B2 (en) Dual fan blower with axial expansion
WO1999024708A1 (en) Cross-flown gas line with a sound absorbent effect
US5279515A (en) Air handling unit with improved acoustical performance
US5551836A (en) High pressure combustion blower assembly
CN1128958C (en) Air Conditioner

Legal Events

Date Code Title Description
AX Request for extension of the european patent to

Free format text: AL;LT;LV;MK;RO;SI

AK Designated contracting states:

Kind code of ref document: A2

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

RIC1 Classification (correction)

Free format text: 7F 24F 7/007 A, 7F 04D 29/42 B, 7F 04D 29/66 B, 7F 24F 13/24 B

AX Request for extension of the european patent to

Free format text: AL;LT;LV;MK;RO;SI

AK Designated contracting states:

Kind code of ref document: A3

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

17P Request for examination filed

Effective date: 20030102

AKX Payment of designation fees

Designated state(s): DE ES FR GB GR IT NL

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

AK Designated contracting states:

Kind code of ref document: B1

Designated state(s): DE ES FR GB GR IT NL

REF Corresponds to:

Ref document number: 69922083

Country of ref document: DE

Date of ref document: 20041230

Kind code of ref document: P

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: GR

Ref legal event code: EP

Ref document number: 20040404537

Country of ref document: GR

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2230824

Country of ref document: ES

Kind code of ref document: T3

ET Fr: translation filed
26N No opposition filed

Effective date: 20050825

PGFP Postgrant: annual fees paid to national office

Ref country code: NL

Payment date: 20070423

Year of fee payment: 9

PGFP Postgrant: annual fees paid to national office

Ref country code: GB

Payment date: 20080317

Year of fee payment: 10

Ref country code: GR

Payment date: 20070430

Year of fee payment: 9

PGFP Postgrant: annual fees paid to national office

Ref country code: DE

Payment date: 20080430

Year of fee payment: 10

PGFP Postgrant: annual fees paid to national office

Ref country code: IT

Payment date: 20080416

Year of fee payment: 10

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20081101

PG25 Lapsed in a contracting state announced via postgrant inform. from nat. office to epo

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20081101

PG25 Lapsed in a contracting state announced via postgrant inform. from nat. office to epo

Ref country code: GR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20081104

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20090416

PG25 Lapsed in a contracting state announced via postgrant inform. from nat. office to epo

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091103

PG25 Lapsed in a contracting state announced via postgrant inform. from nat. office to epo

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090416

PGFP Postgrant: annual fees paid to national office

Ref country code: ES

Payment date: 20100505

Year of fee payment: 12

PG25 Lapsed in a contracting state announced via postgrant inform. from nat. office to epo

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090416

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20120604

PG25 Lapsed in a contracting state announced via postgrant inform. from nat. office to epo

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20110417

PGFP Postgrant: annual fees paid to national office

Ref country code: FR

Payment date: 20120504

Year of fee payment: 14

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20131231

PG25 Lapsed in a contracting state announced via postgrant inform. from nat. office to epo

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20130430