EP0452387B1 - Filtre pour la separation de particules a partir de gaz - Google Patents

Filtre pour la separation de particules a partir de gaz Download PDF

Info

Publication number
EP0452387B1
EP0452387B1 EP90901699A EP90901699A EP0452387B1 EP 0452387 B1 EP0452387 B1 EP 0452387B1 EP 90901699 A EP90901699 A EP 90901699A EP 90901699 A EP90901699 A EP 90901699A EP 0452387 B1 EP0452387 B1 EP 0452387B1
Authority
EP
European Patent Office
Prior art keywords
filter
gases
members
dust
fibres
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
EP90901699A
Other languages
German (de)
English (en)
Other versions
EP0452387A1 (fr
Inventor
Rolf Hunt
Peter Odenmo
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.)
UK Secretary of State for Defence
ABB Technology FLB AB
Original Assignee
UK Secretary of State for Defence
ABB Flaekt AB
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
Application filed by UK Secretary of State for Defence, ABB Flaekt AB filed Critical UK Secretary of State for Defence
Priority to AT90901699T priority Critical patent/ATE103209T1/de
Publication of EP0452387A1 publication Critical patent/EP0452387A1/fr
Application granted granted Critical
Publication of EP0452387B1 publication Critical patent/EP0452387B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
    • B03C3/02—Plant or installations having external electricity supply
    • B03C3/04—Plant or installations having external electricity supply dry type
    • B03C3/14—Plant or installations having external electricity supply dry type characterised by the additional use of mechanical effects, e.g. gravity
    • B03C3/155—Filtration

Definitions

  • the present invention relates to a filter for separating particles from gases by screening, comprising bag-shaped filter members made of textile filter material, each filter member having at least one opening for discharging the gases flowing through the filter material of said filter member, pervious stiffening means arranged inside said filter members, and electrically conductive means arranged inside and outside the filter members for charging said fibres, the electrically conductive means inside the filter members consisting of the said stiffing means, and the electrically conductive means outside the filter members consisting of electrodes.
  • a filter of this type is disclosed in US-A-3,910,779 and when such filters are used for cleaning dust-laden gases, for example flue gases from refuse incineration plants, the dust accumulated on the outsides of the filter members should form dust cakes as thick as possible. This is due to the fact that the cleaning effect of the filter increases with the thickness of the dust cake; the longer the distance the gases have to travel through the filter members, the greater the chance of collecting the dust contained in the gases.
  • these filters are provided with electrically conductive means that enhance the dust particles ability to form large dust particles the dust cakes formed by the dust particles will be porous. This means that the resistance and consequently the pressure drop across the dust cakes will be moderate even for thick dust cakes. Consequently, the thickness of the dust cakes will not be limited by the pressure drop but by the density of the dust cakes. If the density is too high the dust cakes have a tendency to fall off the filter members before they have become thick enough for producing a satisfactory efficiency.
  • the filter is used in a plant for cleaning flue gases from a refuse incineration plant, it is especially difficult to maintain thick dust cakes on the filter members, since gaseous hydrogen chloride and, if the refuse is humid, considerable amounts of water vapour are formed.
  • lime is supplied upstream of the filter in a contact reactor, the hydrogen chloride will react with the lime and form calcium chloride which is hygroscopic.
  • the presence of calcium chloride causes the dust cakes to attract water vapour, making them compact, heavy and sticky.
  • the tendency of the dust cakes to fall off the filter members will be considerable so that the thickness of the dust cakes will not be sufficient for producing a satisfactory separation of the particulate and gaseous impurities of the flue gases, and the filter will be difficult to clean.
  • the filter operating temperature is in this case at a level too low for the remaining process.
  • a powdery catalyst material is applied to the outsides of the filter members, and ammonia is added to the gases ahead of the filter, the latter may be used for catalytic reduction of nitrogen oxides in the gases.
  • the catalyst material in many cases has such a high density that the catalyst material layers formed on the outsides of the filter members become so heavy that they fall off the filter members before they have become thick enough for a satisfactory nitrogen oxide reduction.
  • the object of the present invention is, therefore, to provide a gas cleaning filter which imparts to the dust cakes or the catalyst material layers a sufficient thickness to obtain a satisfactory separation of the particulate and gaseous impurities of the gases in all filter applications, i.e. also in a plant for cleaning flue gases from a refuse incineration plant.
  • a voltage of 0-50 kV, especially 20 kV, has been applied between the stiffening means and the electrodes.
  • the stiffening means may be earthed, and to the electrodes a voltage of 0-50 kV, preferably 20 kV, may be applied.
  • the electrodes may be earthed, and to the stiffening means a voltage of 0-50 kV, preferably 20 kV, may be applied.
  • the textile filter material preferably is of PTFE (TEFLON).
  • the fibres hanging loosely from the filter medium preferably consist of PTFE (TEFLON) and usually have a length of 10-50 mm, preferably 30 mm, and a thickness smaller than or equalling 0.2 mm, preferably 0.1 mm.
  • Fig. 1 is a longitudinal sectional view of a bag filter according to the invention.
  • Fig. 2 is an enlarged part sectional view of Fig. 1.
  • the bag filter 1 shown in Fig. 1 comprises a filter housing 2, an inlet 3 for the gases, e.g. flue gases from a refuse incineration plant, to be cleaned, and an outlet 4 for the cleaned gases.
  • a plate 5 divides the inside of the filter housing into a raw gas chamber 2a and a clean gas chamber 2b communicating with the inlet and the outlet, respectively.
  • the bag filter usually comprises 100-500, especially 300, filter bags 7 arranged in longitudinal and transverse rows. At their upper open end, these filter bags are detachably mounted in holes 6 in the plate 5 by means of a conventional attachment (not shown).
  • the length of the filter bags is 3-5 m, usually 5 m, and their diameter is 100-200 mm, usually 125-130 mm.
  • the longitudinal distance between two adjacent filter bags 7 is 300-500 mm, usually 400 mm.
  • the transverse spacing is 300-500 mm, usually 400 mm.
  • Electrodes 8 are arranged between the filter bags such that one electrode is positioned at each point of intersection between the diagonal lines of four longitudinally and transversely adjacent filter bags.
  • the electrodes have the same length, but are thinner than the filter bags and in the form of round rods. Their diameter is 20-40 mm, usually 30 mm.
  • the electrodes are inserted through holes (not shown) in the plate 5 and are kept in place by means of holders (not shown), such that they have no contact with the plate 5. A voltage of 20 kV has been applied to the electrodes via their holders.
  • Nozzle tubes 9 with nozzles 10 are transversely arranged over the filter bags 7, such that one nozzle is positioned over the upper open end of each filter bag. Consequently, each filter bag, when being cleaned, receives a direct injection of cleaning air supplied to the nozzles from a pressure tank (not shown) via the nozzle tubes. The cleaning air is supplied to one nozzle tube at a time, in the form of a short strong pulse of compressed air.
  • the nozzle tubes are detachably mounted in the clean gas chamber 2b for exchange of filter bags. For the same reason, the top of the filter housing 2 is provided with a number of doors 11 positioned over the nozzle tubes 9.
  • the bottom of the filter housing 2 is funnel-shaped to serve as a dust pocket for collecting the dust separated from the raw gas.
  • the dust is then fed to a dust container (not shown) by means of a screw conveyor (not shown).
  • the fitter bags 7 are mounted round stiffening means 12 in the form of cages which, in conventional manner, are shaped such that they do not interfere with the movement of the gas flow through the filter bags. Furthermore, these cages are earthed via the plate 5.
  • Fig. 2 It is also apparent from Fig. 2 that the outsides of the filter bags are provided with fibres 13 hanging loosely from the filter material of the filter bags. These fibres are usually made of the same textile material as the filter. Since such materials can withstand higher operating temperatures, when surrounded by thick dust cakes, the choice of the material is determined by the filter operating temperature and the thickness of the dust cake 14 forming round the fibres 13.
  • Acryl is a suitable material for operating temperatures of 60-130°C polyester for temperatures of 130-150°C RYTON for temperatures of 150-180°C, and TEFLON for temperatures of 180-240°C.
  • the length of the fibres is 10-50 mm, preferably 30 mm, and the thickness is smaller than or equalling 0.2 mm, preferably 0.1 mm.
  • the bag filter operates as follows.
  • the dust-laden gases to be cleaned in the bag filter are conducted, under a certain excess pressure, into the raw gas chamber 2a the filter housing 2 via the inlet 3. Since the inlet is positioned at the upper end of the filter bags, the gases will flow vertically downwards along the outsides thereof (see Fig. 1), i.e. leading of the gases co-acts with gravity. Consequently, the dust released by the cleaning of the filter bags 7 will not be recycled to the bags by the incoming gases.
  • the cleaned gases flow from the inside of the filter bags to the clean gas chamber 2b and, via the outlet 4, to a chimney (not shown) and are discharged into the atmosphere (see Fig. 1).
  • the fibres hanging loosely on the outsides of the filter bags will also have a reinforcing effect on the dust cakes of the filter bags, such that the heavy dust cakes usually formed on the outsides of the filter bags when the filter is used as an NO x -catalyst, will remain on the filter bags.
  • a different voltage than 20 kV may of course be applied between the electrodes and the cages, but it should preferably be 0-50 kV to make it possible to obtain maximum results.
  • the round rod electrodes may, of course, also be of square or spiral form.

Landscapes

  • Filtering Of Dispersed Particles In Gases (AREA)
  • Electrostatic Separation (AREA)

Abstract

Le filtre décrit (1), qui sert à séparer des particules à partir de gaz par criblage, comprend des éléments de filtrage en forme de sacs (7) qui sont fabriqués à partir d'un matériau de filtre et qui comportent chacun au moins une ouverture pour la décharge des gaz s'écoulant à travers le matériau de filtre des organes de filtrage. Le filtre (1) comprend en outre des organes raidisseurs perméables disposés à l'intérieur des éléments de filtrage. Les faces extérieures des éléments de filtrage (7) sont pourvues de fibres (13) suspendues flottantes au matériau de filtrage ainsi que des organes électroconducteurs (8) disposés à l'intérieur et/ou à l'extérieur des éléments de filtrage et servant à charger lesdites fibres.

Claims (6)

  1. Filtre destiné à séparer des particules de gaz par tamisage, comprenant des éléments filtrants en forme de sac (7) faits de matière filtrante textile, chaque élément filtrant ayant une ouverture au moins pour laisser sortir les gaz s'écoulant à travers la matière filtrante dudit élément, des moyens raidisseurs perméables (12) prévus à l'intérieur des éléments filtrants, et des moyens électroconducteurs (12, 8) prévus à l'intérieur et à l'extérieur des éléments filtrants, les moyens électroconducteurs prévus à l'intérieur des éléments filtrants (7) étant constitués par lesdits moyens raidisseurs (12), et les moyens électroconducteurs prévus à l'extérieur des éléments filtrants (7) étant constitués par des électrodes (8), caractérisé en ce que les faces extérieures des éléments filtrants (7) sont munies de fibres (13) suspendus librement à la matière filtrante, et en ce que lesdites fibres sont chargées par les moyens électroconducteurs (12, 8).
  2. Filtre selon la revendication 1, caractérisé en ce qu'une tension de 0-50 kV, de préférence de 20 kV, a été appliquée entre les moyens raidisseurs (12) et les électrodes (8).
  3. Filtre selon la revendication 2, caractérisé en ce que les moyens raidisseurs (12) sont mis à la terre, et en ce qu'une tension de 0-50 kV, de préférence de 20 kV, a été appliquée aux électrodes (8).
  4. Filtre selon la revendication 2, caractérisé en ce que les électrodes (8) sont mis à la terre, et en ce qu'une tension de 0-50 kV, de préférence de 20 kV, a été appliquée aux moyens raidisseurs (12).
  5. Filtre selon l'une quelconque des revendications précédentes, caractérisé en ce que la matière filtrante est le PTFE (TEFLON).
  6. Filtre selon l'une quelconque des revendications précédentes, caractérisé en ce que les fibres (13) suspendus librement au filtre consistent de PTFE (TEFLON) et ont une longueur de 10-50 mm, de préférence de 30 mm, et une épaisseur inférieure ou égale à 0,2 mm, de préférence de 0,1 mm.
EP90901699A 1989-01-03 1990-01-02 Filtre pour la separation de particules a partir de gaz Expired - Lifetime EP0452387B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT90901699T ATE103209T1 (de) 1989-01-03 1990-01-02 Filter zum abtrennen von teilchen aus gasen.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8900017A SE462615B (sv) 1989-01-03 1989-01-03 Filter foer rening av gaser
SE8900017 1989-01-03

Publications (2)

Publication Number Publication Date
EP0452387A1 EP0452387A1 (fr) 1991-10-23
EP0452387B1 true EP0452387B1 (fr) 1994-03-23

Family

ID=20374672

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90901699A Expired - Lifetime EP0452387B1 (fr) 1989-01-03 1990-01-02 Filtre pour la separation de particules a partir de gaz

Country Status (7)

Country Link
EP (1) EP0452387B1 (fr)
JP (1) JPH04502577A (fr)
AU (1) AU4836290A (fr)
CA (1) CA2045146A1 (fr)
DE (1) DE69007611D1 (fr)
SE (1) SE462615B (fr)
WO (1) WO1990007382A1 (fr)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19542859A1 (de) * 1995-11-17 1997-05-22 Hosokawa Mikropul Ges Fuer Mah Oberflächenfiltration- und -filter
US5938818A (en) * 1997-08-22 1999-08-17 Energy & Environmental Research Center Foundation Advanced hybrid particulate collector and method of operation
WO2002066167A1 (fr) * 2001-02-23 2002-08-29 Elex Ag Depoussiereur electrostatique a tubes de filtration integres
US6544317B2 (en) 2001-03-21 2003-04-08 Energy & Environmental Research Center Foundation Advanced hybrid particulate collector and method of operation
KR100453930B1 (ko) * 2002-08-29 2004-10-20 한국에너지기술연구원 조합형 집진장치
KR101181546B1 (ko) * 2005-11-02 2012-09-10 엘지전자 주식회사 정전식모 섬유를 포함하는 공기정화기
US7990650B2 (en) * 2006-07-14 2011-08-02 Hitachi Global Storage Technologies, Netherlands B.V. Reducing the obstruction of air flow through a bypass channel associated with a disk drive using an electrostatic pass-by filter

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3018845A (en) * 1957-12-12 1962-01-30 Milton A Powers Filters
NL256788A (fr) * 1958-09-12
US3910779A (en) * 1973-07-23 1975-10-07 Gaylord W Penney Electrostatic dust filter
EP0142547B1 (fr) * 1983-05-10 1987-04-29 Industriell Arbetshygien I Söderhamn Ab Dispositif de filtrage pour purification d'air ou de gaz

Also Published As

Publication number Publication date
JPH04502577A (ja) 1992-05-14
AU4836290A (en) 1990-08-01
EP0452387A1 (fr) 1991-10-23
SE462615B (sv) 1990-07-30
DE69007611D1 (de) 1994-04-28
CA2045146A1 (fr) 1990-07-04
WO1990007382A1 (fr) 1990-07-12
SE8900017D0 (sv) 1989-01-03

Similar Documents

Publication Publication Date Title
US5217511A (en) Enhancement of electrostatic precipitation with electrostatically augmented fabric filtration
KR100348168B1 (ko) 필터와 정전기적 분리기의 조합
US6932857B1 (en) Multi-stage collector and method of operation
US4308036A (en) Filter apparatus and method for collecting fly ash and fine dust
CA1037882A (fr) Methode pour l'extraction de solides finement divises en presence dans un gaz
US4973459A (en) Apparatus and method for removing gaseous contaminants and particulate contaminants from a hot gas stream
EP0301630B1 (fr) Dispositif de filtration
US4374652A (en) Filter apparatus and method for collecting fly ash and fine dust
US5308590A (en) Apparatus for removing particulate matter and gases from a polluted gas stream
EP1361927A1 (fr) Depoussiereur electrostatique a tubes de filtration integres
EP0452387B1 (fr) Filtre pour la separation de particules a partir de gaz
US3668836A (en) Electrostatic precipitator
SK15672002A3 (sk) Prachový filter
US20030177901A1 (en) Multi-stage collector
US4290786A (en) Apparatus for removing particulate matter from a gas stream
US4000995A (en) Particulate bed dust collectors
US4976934A (en) Nested, recirculating-fiber filter
SU1039571A1 (ru) Горизонтальный электрофильтр
CN214972821U (zh) 一种物理阻隔吸附气-液-固分离装置
CN113209767A (zh) 一种物理阻隔吸附气-液-固分离装置及方法
DE3707625C2 (de) Verfahren und Vorrichtung zur Behandlung von fluidisierten Schüttgütern in Wirbelschichtapparaten
GB2131330A (en) Electrostatic dust separator
KR910004772B1 (ko) 순환 유동상 반응기 및 그 반응실로부터 나오는 가스에 함유된 고체의 분리 방법
JPH02194866A (ja) フイルター装置

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19910617

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB IT LI LU NL SE

17Q First examination report despatched

Effective date: 19921023

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE DK ES FR GB IT LI LU NL SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19940323

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRE;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.SCRIBED TIME-LIMIT

Effective date: 19940323

Ref country code: DK

Effective date: 19940323

Ref country code: LI

Effective date: 19940323

Ref country code: BE

Effective date: 19940323

Ref country code: DE

Effective date: 19940323

Ref country code: FR

Effective date: 19940323

Ref country code: AT

Effective date: 19940323

Ref country code: SE

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19940323

Ref country code: CH

Effective date: 19940323

Ref country code: ES

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19940323

REF Corresponds to:

Ref document number: 103209

Country of ref document: AT

Date of ref document: 19940415

Kind code of ref document: T

REF Corresponds to:

Ref document number: 69007611

Country of ref document: DE

Date of ref document: 19940428

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

EN Fr: translation not filed
NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19950102

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

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

Effective date: 19950131

26N No opposition filed
GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19950102