DK159669B - MUFFLER - Google Patents

MUFFLER Download PDF

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Publication number
DK159669B
DK159669B DK214483A DK214483A DK159669B DK 159669 B DK159669 B DK 159669B DK 214483 A DK214483 A DK 214483A DK 214483 A DK214483 A DK 214483A DK 159669 B DK159669 B DK 159669B
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DK
Denmark
Prior art keywords
covered
flow
intermediate portion
porous
portions
Prior art date
Application number
DK214483A
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Danish (da)
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DK214483A (en
DK214483D0 (en
DK159669C (en
Inventor
Berit Irene Persson
Original Assignee
Bahco Ventilation Ab
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Publication of DK214483D0 publication Critical patent/DK214483D0/en
Publication of DK214483A publication Critical patent/DK214483A/en
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Publication of DK159669C publication Critical patent/DK159669C/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
    • F24F13/24—Means for preventing or suppressing noise
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N1/00—Silencing apparatus characterised by method of silencing
    • F01N1/24—Silencing apparatus characterised by method of silencing by using sound-absorbing materials
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
    • F16L55/02—Energy absorbers; Noise absorbers
    • F16L55/033—Noise absorbers

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Exhaust Silencers (AREA)
  • Duct Arrangements (AREA)
  • Building Environments (AREA)

Description

iin

DK 159669 BDK 159669 B

Opfindelsen angår en lyddamper, som er beregnet til ventilationskanaler eller ventilationsapparater og består af et eller flere porøse elementer af f.eks. mineraluld, som tjener som resistivt lydabsorberingsmiddel, hvilke elementer er anbragt i 5 luftstrømmen i en kanal eller et apparathylster og indrettet som lydskærme, der omskylles af luftstrømmen, og hvor et eller flere af de porøse elementer på deres langs luftstrømmens strømningsbaner forløbende flader har både af ugennembrudt arkformet materiale dækkede partier og partier, som enten er frie 10 eller dækket af gennembrudt materiale.BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a silencer intended for ventilation ducts or ventilation apparatus and consists of one or more porous elements of e.g. mineral wool which serves as a resistive sound absorber, which elements are disposed in the air flow in a duct or apparatus housing and arranged as sound screens which are flushed by the air flow, and wherein one or more of the porous elements on their surfaces extending along the flow paths of the air stream have both non-breakthrough sheet-shaped material covered portions and portions which are either free or covered with pervious material.

Tidligere kendte dæmpere af denne type har i almindelighed en ikke fuldt ud tilfredsstillende lavfrekvensdæmpning. Lyddæmpere af andre typer, f.eks. membranabsorberingsmidler, som 15 frembyder bedre lavfrekvensdæmpning, er kendte, men lyddæmpere af den førstnævnte type er af flere andre årsager ofte at foretrække.Prior art dampers of this type generally have a not fully satisfactory low frequency attenuation. Mufflers of other types, e.g. membrane absorbers which provide better low frequency attenuation are known, but silencers of the former type are often preferred for several other reasons.

Pra svensk patentskrift nr. 410.217 kendes en lyddæmper af den 20 indledningsvis nævnte type. Oet heri anvendte porøse element har hele den ene side dækket, medens den anden i alt væsentligt er fuldstændig fri. Som følge heraf bliver tykkelsen af det porøse element akustisk virksomt ved resistiv dæmpning.Pra Swedish Patent Specification No. 410,217 discloses a silencer of the type mentioned initially. The porous element used herein covers the whole of one side, while the other is substantially completely free. As a result, the thickness of the porous element becomes acoustically active by resistive damping.

25 Formålet med opfindelsen er derfor at tilvejebringe en i henseende til lavfrekvensdæmpningen forbedret lyddæmper af den indledningsvis beskrevne type, hvis højfrekvensdæmpning til trods herfor tilgodeser et i ventilationsinstallationer værende behov.The object of the invention is therefore to provide an improved sound attenuator of the type described initially, whose high frequency attenuation nevertheless meets a need in ventilation installations.

3030

Det ønskede resultat opnås ved, at lyddæmperen bibringes de karakteristiske træk, der fremgår af det efterfølgende patentkrav 1.The desired result is achieved by imparting the silencer to the characteristic features of the following claim 1.

35 Herved opnås, at der tilvejebringes en lyddæmper, som yder både resistiv og reaktiv dæmpning. Dette skyldes især, at det porøse element på begge sider har afdækkede endepartier og etHereby it is obtained that a silencer is provided which provides both resistive and reactive attenuation. This is mainly because the porous element on both sides has exposed end portions and one

DK 159669 BDK 159669 B

2 frit mellemparti, så at hver elementende har et lommelignende rum, hvori enden af det porøse element er beliggende. Disse lommelignende rum tjener direkte som reaktive dæmpere inden for det aktuelle lavfrekvensområde.2 is a free intermediate portion so that each element end has a pocket-like space in which the end of the porous element is located. These pocket-like compartments serve directly as reactive dampers within the current low frequency range.

55

En udførelsesform for opfindelsen beskrives nedenfor under henvisning til tegningen, hvor fig. 1 viser en lyddæmper, som er beregnet til en ventilations-10 kanal med rektangulært kanal tværsnit, og fig. 2 en i lyddæmperen ifølge opfindelsen 1 indgående lydskærm.An embodiment of the invention is described below with reference to the drawing, in which fig. 1 shows a silencer intended for a rectangular duct ventilation duct 10; and FIG. 2 shows a sound screen included in the muffler according to the invention 1.

15 Den i fig. 1 viste lyddæmper består af seks i form af lydskærme anbragte elementer 1 og 2, der er anbragt i et hylster, som udgøres af en almindelig ventilationskanal med rektangulært tværsnit. Hylsteret er således fremstillet på normal måde af stålplade. Lydskærmenes porøse materiale består passende af 20 mineraluld.15 The embodiment of FIG. 1, the silencer shown in Fig. 1 consists of six sound screens arranged in the form of sound screens 1 and 2, which are arranged in a casing, which is a regular ventilation duct with rectangular cross-section. The casing is thus made in the normal manner of steel plate. The porous material of the sound screens is suitably made up of 20 mineral wool.

Den i fig. 1 viste lyddæmper er sammensat af tre rækker af lydskærme, som hver består af to lydskærme, hvis ender er anbragt stødende op til hinanden. Rækkerne er orienteret på 25 langs af luftstrømmens gennemstrømningsretning. Lydskærmene 2 omskyl les af luftstrømmen, medens l.ydskærmene 1 er placeret op imod tilstødende kanalvægge, og som følge heraf bestryges de kun af luftstrømmen på den ene side.The FIG. 1, the muffler shown is composed of three rows of sound screens, each of which consists of two sound screens whose ends are adjacent to each other. The rows are oriented at 25 along the direction of air flow. The sound screens 2 are flushed by the air flow, while the sound screens 1 are positioned against adjacent duct walls, and as a result they are only covered by the air flow on one side.

30 Opbygningen af en lydskærm 2 fremgår tydeligere af fig. 2.30 The structure of an audio screen 2 is more clearly seen in FIG. 2nd

Hver lydskærm har sin opstrøms- og nedstrømsende 4, 5 omsluttet af i alt væsentligt uigennemtrængeligt arkmateriale 6, fortrinsvis plademateriale, som strækker sig et stykke langs lydskærmens sideflader på langs af luftstrømmens strømnings-35 bane. Disse sideflader har imellem de partier, der er dækket af det i alt væsentligt ugennembrudte materiale 6, et mellem-parti 7, som er frit beliggende eller (ikke vist i fig. 2) dækket af et gennembrudt materiale.Each audio screen has its upstream and downstream ends 4,5, enclosed by substantially impervious sheet material 6, preferably sheet material, which extends a distance along the side surfaces of the audio screen along the flow path of the airflow. These side surfaces have between the portions covered by the substantially unbroken material 6 an intermediate portion 7 which is freely located or (not shown in Fig. 2) covered by a pervious material.

Claims (6)

1. Lyddæmper, beregnet til ventilationskanaler eller ventilationsapparater samt bestående af et eller flere porøse ele- 35 DK 159669 B menter (2) af f.eks. mineraluld, der tjener som resistivt lyd-absorberingsmiddel, hvilke elementer er anbragt i luftstrømmen i en kanal ellet et apparathylster og indrettet som lydskærme, der omskylles af luftstrømmen, og hvor et eller flere af de 5 porøse elementer (2) på deres langs luftstrømmens strømnings-baner forløbende flader har både af ugennembrudt arkformet materiale (6) dækkede partier og partier (7), som enten er frie eller dækket af gennembrudt materiale, kendetegnet ved, at hver af de nævnte flader, set i strømningsretningen er 10 opdelt i tre partier (6,7), nemlig et mellemparti (7), som er frit eller dækket af det gennembrudte materiale, og to op til mellempartiet (7) stødende endepartier (6), som sammen med elementets endeflader er dækket af det ugennembrudte materiale. 151. Silencer intended for ventilation ducts or ventilation apparatus and consisting of one or more porous elements (2) of e.g. mineral wool which serves as a resistive sound absorber, which elements are arranged in the air flow in a duct or an apparatus housing and arranged as sound screens which are flushed by the air flow and wherein one or more of the 5 porous elements (2) on them flow along the air flow paths extending surfaces have both portions of unbroken sheet-shaped material (6) covered and portions (7) which are either free or covered with pervious material, characterized in that each of said surfaces, seen in the flow direction, is divided into three portions. (6,7), namely an intermediate portion (7) which is free or covered by the breakthrough material, and two adjacent end portions (6) adjacent to the intermediate portion (7) which, together with the end faces of the element, are covered with the non-breakthrough material. 15 2. Lyddæmper ifølge krav 1, kendetegnet ved, at mellempartiet (7) er dækket af perforeret plade, strækmetal eller lignende materiale med mindst 20% frit areal.Silencer according to claim 1, characterized in that the intermediate portion (7) is covered with perforated plate, stretch metal or similar material with at least 20% free area. 3. Lyddæmper ifølge krav 1 eller 2, kendetegnet ved, at at det ugennembrudte materiale (6) strækker sig over ca. 2/3 af det porøse elements (2) udstrækning (L) i luftstrømmens strømningsretning eller lydudbredelsesretningen, og at det mellemliggende parti (7) er i hovedsagen centreret i 25 forhold til det porøse elements (2) nævnte udstrækning (L).Silencer according to claim 1 or 2, characterized in that the breakthrough material (6) extends over approx. 2/3 of the extent (L) of the porous element (2) in the direction of flow of air or the sound propagation direction, and that the intermediate portion (7) is substantially centered relative to the extent (L) of the porous element (2). 4. Lyddæmper ifølge krav 3, kendetegnet ved, at det porøse elements (2) nævnte udstrækning (L) udgør omkring 1/4 af bølgelængden for den lavfrekvens, som tilsigtes at 30 blive kraftigere dæmpet end, hvad absorberingsmidlet i sig selv muliggør.Silencer according to claim 3, characterized in that said extent (L) of the porous element (2) constitutes about 1/4 of the wavelength of the low frequency which is intended to be more attenuated than what the absorbent itself allows. 5. Lyddæmper ifølge et eller flere af kravene 1-4, kendetegnet ved, at det ugennembrudte materiale (6) i 35 hver ende af det enkelte porøse element (2) udgøres af en plade, som dækker elementets (2) gavlende, og er bukket omkring to modstående af dennes kanter for at strække sig langs de to af elementets sider, der bestryges af luftstrømmen. DK 159669 BSilencer according to one or more of claims 1-4, characterized in that the non-breakthrough material (6) at each end of the individual porous element (2) is constituted by a plate which covers the end of the element (2) and is bent about two opposite sides of its edges to extend along the two sides of the element, which is coated by the flow of air. DK 159669 B 5 Det i alt væsentligt ugennembrudte materiale 6 strækker sig passende over ca. 2/3 af det porøse elements udstrækning L i luftstrømmens strømningsretning eller lydudbredelsesretningen. Herved er det mellemliggende parti 7 i hovedsagen centreret på strækningen L. 10 Strækningen L vælges endvidere passende således, at den er ca. 1/4 af bølgelængden af den lavfrekvens, som tilsigtes at blive kraftigere dæmpet end absorberingsmidlet i sig selv muliggør.Suitably, the substantially unbroken material 6 extends over ca. 2/3 of the porous element's extension L in the flow direction of the air flow or the direction of sound propagation. Hereby, the intermediate portion 7 is substantially centered on the line L. 10 The line L is furthermore appropriately selected so that it is approx. 1/4 of the wavelength of the low frequency which is intended to be more attenuated than the absorbent itself allows. 15 Lydskærmen er ifølge fig. 2 opbygget af et porøst element i form af et lige parallelepipedumformet legeme, som i hver ende har en ugennembrudt plade 6, som dækker elementets gavl og er bukket omkring dets kanter samt strækker sig et stykke langs de af elementets sider, der bestryges af luftstrømmen. Oe på 20 disse elementsider beliggende partier af pladerne 6 er vist plane og tildannet med sine afsluttende kanter mod det mellemliggende frie parti 7 af elementet orienteret i alt væsentligt vinkelret på pladernes langsgående kanter langs elementsiderne. 25 Den ovenfor beskrevne lyddæmper frembyder takket være den nævnte partielle indeslutning ved hjælp af det i alt væsentligt ugennembrudte arkformede materiale 6, en kombination af resistiv og reaktiv dæmpning. Resultatet heraf er en i alt væ-30 sentligt forbedret lavfrekvensdæmpning uden uheldig stor reducering af højfrekvensdæmpningen. Patentkrav.15 According to FIG. 2 is constructed of a porous element in the form of a straight parallelepiped shaped body, which has at each end a non-pierced plate 6, which covers the end of the element and is bent around its edges and extends a distance along the sides of the element which is covered by the flow of air. Oe on 20 of these element sides located portions of the plates 6 are shown planar and formed with their terminating edges towards the intermediate free portion 7 of the element oriented substantially perpendicular to the longitudinal edges of the plates along the element sides. The abovementioned muffler, thanks to said partial enclosure, offers, by means of the substantially unbroken sheet-shaped material 6, a combination of resistive and reactive damping. The result is a substantially improved low frequency attenuation without unduly large reduction of the high frequency attenuation. Claims. 6. Lyddæmper ifølge krav 5, kendetegnet ved, at hver gavlendes plade (6) langs den af luftstrømmen bestrøgne side er plan og i alt væsentlig retvinklet afsluttet op til det nævnte mellemliggende parti (7). 10 15 20 25 30 35Silencer according to Claim 5, characterized in that the plate (6) of each endplate (6) along the side covered by the airflow is flat and substantially at right angles to the intermediate portion (7). 10 15 20 25 30 35
DK214483A 1982-05-14 1983-05-13 MUFFLER DK159669C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8203030 1982-05-14
SE8203030A SE450656B (en) 1982-05-14 1982-05-14 Muffler for ventilation ducts or ventilation equipment

Publications (4)

Publication Number Publication Date
DK214483D0 DK214483D0 (en) 1983-05-13
DK214483A DK214483A (en) 1983-11-15
DK159669B true DK159669B (en) 1990-11-12
DK159669C DK159669C (en) 1991-04-15

Family

ID=20346812

Family Applications (1)

Application Number Title Priority Date Filing Date
DK214483A DK159669C (en) 1982-05-14 1983-05-13 MUFFLER

Country Status (7)

Country Link
DE (1) DE3317273A1 (en)
DK (1) DK159669C (en)
FI (1) FI75415C (en)
FR (1) FR2526860B1 (en)
GB (1) GB2122256B (en)
NO (1) NO162931C (en)
SE (1) SE450656B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110770511A (en) * 2017-04-14 2020-02-07 弗劳恩霍夫应用研究促进协会 Split muffler assembly with sound absorbing end sides

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DE3934756A1 (en) * 1989-10-18 1991-04-25 Kuehnle Kopp Kausch Ag Noise damper for axial-flow fan - has adjacent sound absorbing chamber behind diffuser core and/or jacket transversely to flow direction
FI91995C (en) * 1990-11-20 1994-09-12 Valmet Paper Machinery Inc Absorptive silencer, especially for air ducts in paper mills
EP0558472B1 (en) * 1990-11-21 1998-04-08 Sound Attenuators Limited Improvements in attenuators
GB2267731A (en) * 1992-06-10 1993-12-15 Lancaster Glass Fibre Sound absorber insert for an exhaust silencer.
SE506618C2 (en) 1996-12-19 1998-01-19 Flaekt Ab Device and method of noise reduction in a gaseous medium transport system and use of the device in a ship exhaust system
US5801342A (en) * 1997-01-27 1998-09-01 Lindab Ab Double-walled structure and method and arrangement for producing the same
US6062270A (en) * 1997-01-27 2000-05-16 Lindab Ab Double-walled structure in a ventilation duct system
EP0897083A3 (en) * 1997-08-14 2000-03-29 Müller-BBM GmbH Ultrasonic sound attenuator
SE511627C2 (en) * 1997-11-03 1999-11-01 Stifab Farex Ab Muffler baffle for rectangular vents
SE511628C2 (en) * 1997-11-10 1999-11-01 Stifab Farex Ab Silencer with baffles for rectangular ventilation ducts
US6073723A (en) * 1998-06-05 2000-06-13 Gallo; Anthony Acoustic damping material
SE521395C2 (en) * 1998-07-10 2003-10-28 Lindab Ab Double-wall construction in a ventilation duct system and use of a sheet metal strip
US6543575B1 (en) 2000-06-14 2003-04-08 Lindab Ab Double-walled structure and connection arrangement
FI122523B (en) 2008-04-30 2012-03-15 Metso Paper Inc Low-frequency silencer, a method for manufacturing a low-frequency silencer, and a system for low-frequency silencers, for example, in air-conditioning ducts for paper mills
WO2014076355A1 (en) 2012-11-15 2014-05-22 Wärtsilä Finland Oy An exhaust gas noise attenuator unit for internal combustion piston engine
GB2519749B (en) * 2013-10-24 2015-08-05 Bentley Motors Ltd Tyre cavity noise absorber
GB2528950A (en) 2014-08-06 2016-02-10 Aaf Ltd Sound suppression apparatus
JP6851404B2 (en) * 2018-01-31 2021-03-31 富士フイルム株式会社 Silent ventilation structure

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110770511A (en) * 2017-04-14 2020-02-07 弗劳恩霍夫应用研究促进协会 Split muffler assembly with sound absorbing end sides

Also Published As

Publication number Publication date
NO831722L (en) 1983-11-15
NO162931C (en) 1990-03-07
GB2122256A (en) 1984-01-11
SE450656B (en) 1987-07-13
FI75415B (en) 1988-02-29
DE3317273C2 (en) 1991-04-11
DK214483A (en) 1983-11-15
FI75415C (en) 1988-06-09
GB2122256B (en) 1985-11-13
FI831586L (en) 1983-11-15
FR2526860A1 (en) 1983-11-18
DE3317273A1 (en) 1983-11-17
SE8203030L (en) 1983-11-15
FI831586A0 (en) 1983-05-09
DK214483D0 (en) 1983-05-13
NO162931B (en) 1989-11-27
FR2526860B1 (en) 1989-06-16
DK159669C (en) 1991-04-15
GB8312060D0 (en) 1983-06-08

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