EP0225526B1 - Appareil pour traiter un liquid avec des gaz ou pour mélanger des liquides - Google Patents

Appareil pour traiter un liquid avec des gaz ou pour mélanger des liquides Download PDF

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Publication number
EP0225526B1
EP0225526B1 EP86116151A EP86116151A EP0225526B1 EP 0225526 B1 EP0225526 B1 EP 0225526B1 EP 86116151 A EP86116151 A EP 86116151A EP 86116151 A EP86116151 A EP 86116151A EP 0225526 B1 EP0225526 B1 EP 0225526B1
Authority
EP
European Patent Office
Prior art keywords
distributor
gas
chamber
liquid
vibration
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.)
Expired - Lifetime
Application number
EP86116151A
Other languages
German (de)
English (en)
Other versions
EP0225526A2 (fr
EP0225526A3 (en
Inventor
Bruno Gruber
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.)
ABS International SA
Original Assignee
ABS International SA
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 claimed from DE3543022A external-priority patent/DE3543022C1/de
Priority claimed from DE3608970A external-priority patent/DE3608970C1/de
Application filed by ABS International SA filed Critical ABS International SA
Priority to AT86116151T priority Critical patent/ATE85903T1/de
Publication of EP0225526A2 publication Critical patent/EP0225526A2/fr
Publication of EP0225526A3 publication Critical patent/EP0225526A3/de
Application granted granted Critical
Publication of EP0225526B1 publication Critical patent/EP0225526B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20Mixing gases with liquids
    • B01F23/23Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
    • B01F23/238Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids using vibrations, electrical or magnetic energy, radiations
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20Mixing gases with liquids
    • B01F23/23Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
    • B01F23/231Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids by bubbling
    • B01F23/23105Arrangement or manipulation of the gas bubbling devices
    • B01F23/2312Diffusers
    • B01F23/23121Diffusers having injection means, e.g. nozzles with circumferential outlet
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F33/00Other mixers; Mixing plants; Combinations of mixers
    • B01F33/40Mixers using gas or liquid agitation, e.g. with air supply tubes
    • B01F33/409Parts, e.g. diffusion elements; Accessories
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F35/00Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
    • B01F35/71Feed mechanisms
    • B01F35/717Feed mechanisms characterised by the means for feeding the components to the mixer
    • B01F35/71755Feed mechanisms characterised by the means for feeding the components to the mixer using means for feeding components in a pulsating or intermittent manner
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01FMIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/20Mixing gases with liquids
    • B01F23/23Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids
    • B01F23/231Mixing gases with liquids by introducing gases into liquid media, e.g. for producing aerated liquids by bubbling
    • B01F23/23105Arrangement or manipulation of the gas bubbling devices
    • B01F23/2312Diffusers
    • B01F23/23126Diffusers characterised by the shape of the diffuser element
    • B01F23/231264Diffusers characterised by the shape of the diffuser element being in the form of plates, flat beams, flat membranes or films

Definitions

  • the invention relates to a device for gassing a carrier liquid or for admixing an additional liquid to a carrier liquid with a chamber, a gas or liquid inlet opening into the chamber, a distributor which is provided with gas or liquid outlet openings, and a vibration device.
  • a shock pressure wave source which can vibrate or emit sound, is arranged inside a chamber into which gaseous medium is introduced.
  • the shock pressure wave source causes the gas filaments, which pass through the distributor designed as a perforated plate, to be torn off.
  • a gas bubble outlet which comprises a finely perforated oscillator membrane.
  • the gas bubble emitter is immersed in a liquid and, if it is continuously subjected to gas, automatically vibrates, whereby fine gas bubbles are generated in a pulsating manner.
  • the distributor consists of a pulsating sieve plate column which can be moved up and down in a vessel filled with a liquid.
  • the sieve trays are supported by three vertical feed lines through which the gas to be dispersed is led under the lowest sieve tray.
  • Numerous devices are also known for mixing liquids with one another. These known devices involve the introduction of liquid into another liquid by means of mechanical swirling. In order to produce mixtures or emulsions with the known possibilities, a large amount of kinetic energy is consumed. It is also often undesirable to raise the temperature due to the friction that occurs.
  • the invention has for its object to provide a device which enables large amounts of gas or additional liquid to be introduced in finely divided form into a carrier liquid with little energy expenditure, without this having to be brought into turbulent movement and thereby heating up in an often undesirable manner .
  • the object is achieved in that the distributor, the wall opposite this or both are designed or mounted to vibrate relative to the chamber and that the vibrating device is connected to the distributor, to the wall opposite the distributor or to both, and this with vibrations acted upon, the volume of the chamber being pulsatile compressible.
  • the distributor is preferably designed as a membrane, which is set in vibration, for example, with the aid of the vibration device.
  • the distributor can be connected to the chamber via an elastic intermediate layer, so that the distributor can also be designed essentially as a rigid plate, the pulsating compression being effected via the elastic intermediate layer.
  • the vibration device suitably consists of an electromagnetic vibration generator.
  • the vibrating device can be connected to the distributor and / or the wall opposite this via a rigid linkage.
  • the number and size of the escaping gas or liquid bubbles can be set in a wide range with the amount of liquid or gas supply, the number and size of the bores of the distributor, the frequency and amplitude of the oscillation of the vibration generator.
  • the fine bubbles always emerge from the distributor when the vibration generator exerts pressure on the distributor or the membrane and the gas or liquid overpressure on the distributor thus increases.
  • Figure 1 shows a cross section through a device with a distributor 1, which is attached to the edge of the chamber 2, has a gas or liquid supply line 3 and has a vibration device 5, which acts on the membrane 10 via a rigid linkage 4 and that in the Chamber 2 located gas or the liquid can pulsate, so that the distributor 1 releases synchronous to the vibration frequency fine bubbles 6 in a surrounding liquid.
  • Figure 2 shows a cross section through a device with a perforated membrane as a distributor 1, which is attached to the chamber 2, wherein a vibrating device 5 acts on the distributor 1 via a rigid linkage 4.
  • Figure 3 shows a cross section through a device with a rigid perforated plate as a distributor 1, which is fastened to the chamber 2 via an elastic intermediate layer 8 (for example rubber) and has a vibration device 5 which acts on the distributor 1 via a rigid linkage 4 .
  • an elastic intermediate layer 8 for example rubber
  • Figure 4 shows a cross section through a device with a distributor 1, which is inserted into the side of a tube 9 filled with liquid, the vibrating device 5 acting on the membrane 10 with a second linkage 7 inside the chamber 2 providing a rigid connection with the Distributor 1 owns.
  • the distributor 1 consists of a perforated membrane.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
  • Mixers With Rotating Receptacles And Mixers With Vibration Mechanisms (AREA)

Claims (5)

  1. Dispositif pour dissoudre un gaz dans un liquide porteur ou pour mélanger un additif liquide à un liquide porteur, comprenant une chambre (2), une admission de gaz ou de liquide (3) qui débouche dans la chambre (2), un distributeur (1) qui est muni d'orifices de sortie du gaz ou du liquide, ainsi qu'un dispositit vibrateur (5), caractérisé en ce que le distributeur (1), la paroi (10) opposée à lui ou les deux ensemble sont réalisés ou montés de façon à pouvoir vibrer par rapport à la chambre, et en ce que le dispositif vibrateur (5) est raccordé au distributeur (1), à la paroi (10) opposée au distributeur (1) ou aux deux et imprime à ceux-ci des vibrations, le volume de la chambre (2) étant compressible de façon pulsatoire.
  2. Dispositif selon la revendication 1, caractérisé en ce que le distributeur (1) est réalisé sous forme de membrane.
  3. Dispositif selon la revendication 1 ou 2, caractérisé en ce que le distributeur (1) est relié à la chambre (2) par une pièce intermédiaire élastique (8).
  4. Dispositif selon l'une quelconque des revendications 1 à 3, caractérisé en ce que le dispositif vibrateur (5) est réalise sous forme de générateur électromagnétique de vibrations.
  5. Dispositif selon l'une quelconque des revendications 1 à 4, caractérisé en ce que le dispositif vibrateur (5) est relié par une tringlerie rigide (4, 7) au distributeur (1) et/ou à la paroi (10) opposée à celui-ci.
EP86116151A 1985-12-05 1986-11-21 Appareil pour traiter un liquid avec des gaz ou pour mélanger des liquides Expired - Lifetime EP0225526B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86116151T ATE85903T1 (de) 1985-12-05 1986-11-21 Vorrichtung zur begasung von fluessigkeiten oder zur mischung von fluessigkeiten.

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE3543022A DE3543022C1 (en) 1985-12-05 1985-12-05 Appliance for mixing gas into a liquid
DE3543022 1985-12-05
DE3608970 1986-03-18
DE3608970A DE3608970C1 (en) 1986-03-18 1986-03-18 Apparatus for mixing liquids

Publications (3)

Publication Number Publication Date
EP0225526A2 EP0225526A2 (fr) 1987-06-16
EP0225526A3 EP0225526A3 (en) 1988-09-07
EP0225526B1 true EP0225526B1 (fr) 1993-02-24

Family

ID=25838546

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86116151A Expired - Lifetime EP0225526B1 (fr) 1985-12-05 1986-11-21 Appareil pour traiter un liquid avec des gaz ou pour mélanger des liquides

Country Status (4)

Country Link
US (1) US4793714A (fr)
EP (1) EP0225526B1 (fr)
AT (1) ATE85903T1 (fr)
DE (1) DE3687824D1 (fr)

Families Citing this family (36)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5090352A (en) * 1987-02-24 1992-02-25 Corwin R. Horton Bow foil
US5117882A (en) * 1987-02-24 1992-06-02 Corwin R. Horton Microbubble-generating and dispensing devices and methods
DE3735080C1 (de) * 1987-10-16 1988-10-13 Borsig Gmbh Vorrichtung zum Zerstoeren von Schaum
DE3841618A1 (de) * 1988-12-10 1990-06-13 Linde Ag Gaseintragssystem
US5078504A (en) * 1989-02-06 1992-01-07 Spectrum Sciences B.V. Dispersion apparatus
DE4240949C1 (de) * 1992-12-07 1994-01-05 Envicon Klaertech Verwalt Belüftungseinrichtung
FR2699091B1 (fr) * 1992-12-10 1995-02-17 Thomson Csf Procédé de production de particules d'un premier fluide dans un deuxième fluide, les fluides étant non miscibles entre eux, et dispositif pour sa mise en Óoeuvre.
CA2104565A1 (fr) * 1993-08-20 1995-02-21 Richard D. Vanderploeg Capsule de bouteille
JP3396319B2 (ja) * 1993-12-28 2003-04-14 浜松ホトニクス株式会社 液体処理方法および液体処理装置
JP3367038B2 (ja) * 1997-04-21 2003-01-14 株式会社 本家松浦酒造場 アルコール溶液のアルコール分離装置
DE19731099C1 (de) * 1997-07-19 1999-04-01 Henkel Kgaa Vorrichtung zur Einleitung von Schallwellen in Reaktoren
US6039309A (en) * 1997-12-05 2000-03-21 The United States Of America As Represented By The Secretary Of The Navy Method and apparatus for producing gas bubbles in a liquid medium
AU8467998A (en) * 1998-03-30 1999-10-18 Vyacheslav Ivanovich Drobyshev Method for producing foam and device for realising the same
US6398195B1 (en) * 1998-04-10 2002-06-04 Grt, Inc. Method of and apparatus for producing sub-micron bubbles in liquids and slurries
US6270249B1 (en) 1998-09-30 2001-08-07 Robert W. Besuner Vertically reciprocating perforated agitator
IL129208A0 (en) * 1999-03-28 2000-02-17 Liposol Ltd A method and apparatus for nebulizing a liquid particulary useful for the aerosol delivery of biopharmaceuticals
DE10011022A1 (de) * 2000-03-07 2001-09-27 Meinhard Knoll Vorrichtung und Verfahren zur Durchführung von Synthesen, Analysen oder Transportvorgängen
EP1447127B1 (fr) * 2001-02-23 2007-07-04 Japan Science and Technology Agency Dispositif pour produire des émulsions
US6939032B2 (en) * 2001-10-25 2005-09-06 Erie Scientific Company Cover slip mixing apparatus
US20040257907A1 (en) * 2003-06-19 2004-12-23 Agency For Science, Technology And Research Method and apparatus for mixing fluids
US7367550B2 (en) * 2003-11-18 2008-05-06 Massachusetts Institute Of Technology Peristaltic mixing and oxygenation system
US20050122836A1 (en) * 2003-12-05 2005-06-09 Maytag Corporation Stand mixer with control panel
US20060060991A1 (en) * 2004-09-21 2006-03-23 Interuniversitair Microelektronica Centrum (Imec) Method and apparatus for controlled transient cavitation
GB2443396B (en) * 2006-10-30 2011-10-19 Univ Sheffield Bubble generation for aeration and other purposes
US10377651B2 (en) * 2006-10-30 2019-08-13 Perlemax Ltd Bubble generation for aeration and other purposes
EP2294305B1 (fr) * 2008-03-31 2015-07-29 Technion Research & Development Foundation Ltd. Système sonique et procédé de fabrication de mélanges liquide-gaz
FR2935373A1 (fr) * 2008-09-04 2010-03-05 Lm Environment Dispositif de diffusion des boues pour digesteur a lit de boue
GB2479528A (en) * 2010-04-08 2011-10-19 Advanced Fuel Technologies Uk Ltd A device for diffusing gas into a liquid
FR2969506B1 (fr) * 2010-12-22 2013-02-15 Sartorius Stedim Biotech Sa Melange du contenu d'un conteneur flexible a usage biopharmaceutique.
EP2906679A1 (fr) 2012-10-15 2015-08-19 Perlemax Ltd Génération de bulles pour éliminer des constituants d'un liquide
US9403135B2 (en) * 2014-03-18 2016-08-02 Sartorius Stedim North America Inc. Mixing container and mixing system
US9643140B2 (en) 2014-05-22 2017-05-09 MikroFlot Technologies LLC Low energy microbubble generation system and apparatus
US20180085477A1 (en) * 2015-04-08 2018-03-29 Sonocore, Inc. Method for manufacturing bubbles
JP6605229B2 (ja) * 2015-05-11 2019-11-13 国立大学法人群馬大学 気体の微細化装置
WO2017000253A1 (fr) * 2015-06-30 2017-01-05 Kechuang Lin Appareil et système de génération de bulles
IL305263A (en) * 2021-02-18 2023-10-01 Moleaer Inc produces nanobubbles

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB497741A (en) * 1936-07-03 1938-12-28 Ig Farbenindustrie Ag Method for introducing gases into liquids
US2124983A (en) * 1937-08-30 1938-07-26 Martin Joseph Agitator
US2420691A (en) * 1945-05-05 1947-05-20 Vang Alfred Evaporator
US2856273A (en) * 1953-12-28 1958-10-14 Pure Oil Co Apparatus for low velocity fluidization
US3097828A (en) * 1958-04-30 1963-07-16 Grun Gustav Method and apparatus for mixing pulverulent or fine-grain material
US3264213A (en) * 1964-10-27 1966-08-02 Pav Jarmil Method and apparatus for continuous biological degradation of metabolisable substances
DE1917962A1 (de) * 1969-04-09 1971-02-25 Maschf Augsburg Nuernberg Ag Schalldruckpumpen
DE2514197A1 (de) * 1975-04-01 1976-10-14 Linde Ag Vorrichtung zur begasung von fluessigkeiten
US4353668A (en) * 1980-04-29 1982-10-12 North American Car Corporation Hopper bottom unit
DE3039969C2 (de) * 1980-10-23 1983-06-01 Bruno 8039 Puchheim Gruber Vorrichtung zur Erzeugung von Gasblasen oder Schaum

Also Published As

Publication number Publication date
EP0225526A2 (fr) 1987-06-16
US4793714A (en) 1988-12-27
EP0225526A3 (en) 1988-09-07
DE3687824D1 (de) 1993-04-01
ATE85903T1 (de) 1993-03-15

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