EP0166190B1 - Reinigungsvorrichtung für Regenerativ-Wärmetauscher - Google Patents

Reinigungsvorrichtung für Regenerativ-Wärmetauscher Download PDF

Info

Publication number
EP0166190B1
EP0166190B1 EP85106182A EP85106182A EP0166190B1 EP 0166190 B1 EP0166190 B1 EP 0166190B1 EP 85106182 A EP85106182 A EP 85106182A EP 85106182 A EP85106182 A EP 85106182A EP 0166190 B1 EP0166190 B1 EP 0166190B1
Authority
EP
European Patent Office
Prior art keywords
hood
nozzle
nozzle tube
disposed
base part
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
Application number
EP85106182A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0166190A3 (en
EP0166190A2 (de
Inventor
Manfred Tratz
Karl-Heinz Dr. Mohr
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.)
Balcke Duerr AG
Original Assignee
Balcke Duerr AG
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 Balcke Duerr AG filed Critical Balcke Duerr AG
Publication of EP0166190A2 publication Critical patent/EP0166190A2/de
Publication of EP0166190A3 publication Critical patent/EP0166190A3/de
Application granted granted Critical
Publication of EP0166190B1 publication Critical patent/EP0166190B1/de
Expired legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28G—CLEANING OF INTERNAL OR EXTERNAL SURFACES OF HEAT-EXCHANGE OR HEAT-TRANSFER CONDUITS, e.g. WATER TUBES OR BOILERS
    • F28G1/00—Non-rotary, e.g. reciprocated, appliances
    • F28G1/16—Non-rotary, e.g. reciprocated, appliances using jets of fluid for removing debris
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D17/00—Regenerative heat-exchange apparatus in which a stationary intermediate heat-transfer medium or body is contacted successively by each heat-exchange medium, e.g. using granular particles
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28G—CLEANING OF INTERNAL OR EXTERNAL SURFACES OF HEAT-EXCHANGE OR HEAT-TRANSFER CONDUITS, e.g. WATER TUBES OR BOILERS
    • F28G9/00—Cleaning by flushing or washing, e.g. with chemical solvents
    • F28G9/005—Cleaning by flushing or washing, e.g. with chemical solvents of regenerative heat exchanger

Definitions

  • the invention relates to a device for cleaning the heat-exchanging surfaces of the fixed storage masses of regenerative heat exchangers with rotatingly driven hoods by means of a cleaning fluid which emerges from at least one nozzle of a nozzle tube essentially parallel to the planes of the heat-exchanging surfaces, the nozzle tube on the hood of the Regenerative heat exchanger attached and so the nozzle can be moved relative to the fixed storage mass and wherein the nozzle tube is connected by a feed line to a transfer device arranged in the center of rotation of the hood, which comprises a tube piece rotating with the hood and a stationary housing sealed with respect to the tube piece.
  • Cleaning devices for the storage masses of regenerative heat exchangers are known both for rotating storage masses and fixed guide devices as well as for fixed storage masses and rotating hoods.
  • Compressed air or superheated steam is preferably used as the cleaning agent, but sometimes also water, to which anti-corrosion inhibitors and wetting agents or solvents can be added.
  • the cleaning device consists of a nozzle tube attached to the hood, which is provided with nozzles over the entire length.
  • the nozzle tube sweeps over a circular ring and thus cleans the heat-exchanging surfaces of the fixed storage masses underneath.
  • the cleaning fluid is fed to the nozzle pipe via a radial feed line which opens into an axial feed line, the latter being connected to a transfer device arranged in the center of rotation of the hoods.
  • a disadvantage of this known cleaning device is that the nozzle tube lies completely in the flow area within the regenerative heat exchanger and thus adversely affects the flow conditions.
  • a further disadvantage of the known cleaning device is that the throughput quantities of the cleaning fluid are very high, since the nozzle tube has a large number of nozzles.
  • Another cleaning device for a regenerative heat exchanger is known from BE-A-879 153.
  • This consists of a rotatably driven heat exchanger, which is essentially cylindrical.
  • a fixed cleaning device is arranged, which consists of a telescopic nozzle tube with a fixed part.
  • the cleaning fluid is supplied via a hole in the fixed part to the nozzle tube.
  • the cleaning of the heat exchanger is carried out in such a way that it rotates and that the nozzle tube is telescopically displaced back and forth, so that the leakage of the cleaning fluid sprays the entire top of the heat exchanger for cleaning.
  • the object of the invention is to further develop the known cleaning device in such a way that the nozzle tube requires only a small amount of space, so as to minimize the disruptive influence of the nozzle tube on the flow conditions within the regenerative heat exchanger hold.
  • the invention proposes that the nozzle is arranged at the end of an at least two-part, telescopic nozzle tube which is formed from a base part arranged on the hood and a displaceable part that can be displaced relative to the base part, one end of the base part in the region of the The center of rotation and the opposite end of the base part is arranged on the outer circumference of the hood and the entire base part lies in the area of the hood that covers the storage mass, while only the displaceable travel part protrudes into the flow cross section of the flow media.
  • a particularly space-saving and simple cleaning device is created, which essentially consists only of the telescopic nozzle tube and the known transfer device.
  • the nozzle tube provided with at least one nozzle is adjusted in the radial direction relative to the storage mass, so that all the heat-exchanging surfaces of the storage masses are successively cleaned by the rotating movement of the hood.
  • the main part of the telescopic nozzle tube, namely the base part lies in the area of the hood that covers the storage mass, so that only the extendable end of the nozzle tube, namely the moving part, projects into the actual flow cross section of the flow media.
  • the inflow area of this extendable part of the nozzle tube is so small that no or virtually no disturbances in the flow occur.
  • the special arrangement of the telescopic nozzle tube makes it possible in a simple manner to move the nozzle formed at the front end of the displaceable moving part over the entire radius of the standing storage mass.
  • the cleaning device according to the invention can be used for targeted cleaning are, so that the advantage is further achieved that the throughput of the cleaning fluid can be reduced compared to known designs.
  • the moving part of the nozzle tube containing the nozzle is adjustable by an actuator depending on the extent of the surface in each case acted upon by the cleaning fluid, and the telescopic movement of the moving part of the nozzle tube is derived from the rotary movement of the hood.
  • the moving part is connected to an endless, flexible tension element, which is guided via two deflection rollers and whose one deflection roller is connected to a drive wheel, which is driven step by step by at least one stationary stop during the rotary movement of the hood.
  • FIG. 1 The schematic plan view of a regenerative heat exchanger according to FIG. 1 shows a fixed storage mass 1, which is equipped with heat-exchanging surfaces in the direction of view, through which hot flue gases and fresh air to be warmed up alternately flow.
  • the change of these two flow media is achieved by a rotating hood 2.
  • Such a hood 2 is arranged on each of the two end faces of the cylindrical storage mass 1.
  • the direction of rotation of the hood 2 is indicated in Fig. 1 by arrows.
  • a cleaning device is arranged on the hood 2 and thus rotates together with the hood 2.
  • 1 shows a housing 3 of this cleaning device and the front end of a telescopic nozzle tube 4, in which at least one nozzle is formed.
  • a cleaning fluid emerges from this nozzle essentially parallel to the planes of the heat-exchanging surfaces of the storage mass 1.
  • An embodiment of this cleaning device is shown in Fig. 2.
  • the nozzle tube 4 is designed in two parts and telescopic according to the embodiment of FIG. 2. It consists of a base part 4a fastened to the hood 2 and of a moving part 4b which has nozzle openings 4c at its front end.
  • the tubular travel part 4b which is closed at the front end except for the nozzle openings 4c, can be displaced in the longitudinal direction on the base part 4a, as indicated by the double arrow and the dash-dotted lines in FIG. 2.
  • Seals 4d are arranged between base part 4a and travel part 4b, which prevent cleaning fluid from escaping between base part 4a and travel part 4b in any position of the displacement part 4b relative to the base part 4a.
  • the cleaning fluid is fed to the nozzle tube 4 through a feed line 5, which is connected to a stationary line 7 by means of a transfer device 6.
  • a housing 6a is arranged at the end of this line 7 coming from a pressure source for the cleaning fluid.
  • This housing 6a is located in the center of rotation of the hood 2 and is aligned concentrically with the axis of rotation of the hood 2.
  • the open end of a pipe section 6b which is provided with a sealing ring 6c located in the housing 6a, projects into this fixed housing 6a.
  • This piece of pipe 6b with the sealing ring 6c rotates with the hood 2 and, as can be seen in FIG. 2, is connected to the feed line 5.
  • the moving part 4b is designed to be displaceable on the base part 4a.
  • 3 and 4 show an exemplary embodiment of the adjustment device required for this.
  • two deflection rollers 8a and 8b are rotatably mounted in the housing 3, over which an endless flexible tension element, for example a rope 9, runs.
  • a driver 9a is attached to this rope 9.
  • the cable 9 is driven with the aid of a drive wheel 10, which is connected in a rotationally fixed manner to the deflection roller 8a via its shaft 10a.
  • the drive wheel 10 is shown in dashed lines. It can be seen from this illustration that the drive wheel 10 protrudes slightly from the circumference of the hood 2. In this way, the drive wheel 10 provided with projections 10b can be rotated by means of fixed stops 11 when the hood 2 rotates past these fixed stops 11 with the drive wheel 10. The gradual rotation of the drive wheel 10 can be controlled by the arrangement and number of the stops 11, it being possible according to the double arrows drawn in FIG. 3 to either push the stops 11 into the movement area of the projections 10b of the chain wheel 10 or out of this movement area withdraw.
  • the circulating movement of the cable 9 generated with the aid of the drive wheel 10 is used to adjust the moving part 4b relative to the base part 4a.
  • driving bolts 4e are arranged on the moving part 4b.
  • Fig. 4 it is shown that when the driver 9a rotates, first the moving part 4b from the collapsed position of the telescopic nozzle tube 4, in which the nozzle openings 4c are the radially innermost part of the storage mass 1 brush, move radially outwards until the end position of the feed movement is reached. Subsequently, the driver 9a starts the return after its rotation around the deflection roller 8b.
  • the moving part 4b is carried along via the second driving bolt 4e in the direction of the end position of the return movement.
  • the driving bolts 4e are slightly offset from one another in the longitudinal direction of the moving part 4b, as is shown in particular in FIG. 4.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Cleaning In General (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
  • Cleaning By Liquid Or Steam (AREA)
  • Apparatus For Disinfection Or Sterilisation (AREA)
EP85106182A 1984-06-27 1985-05-21 Reinigungsvorrichtung für Regenerativ-Wärmetauscher Expired EP0166190B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3423619A DE3423619C2 (de) 1984-06-27 1984-06-27 Vorrichtung zur Reinigung der wärmetauschenden Flächen der Speichermassen von Regenerativ-Wärmetauschern
DE3423619 1984-06-27

Publications (3)

Publication Number Publication Date
EP0166190A2 EP0166190A2 (de) 1986-01-02
EP0166190A3 EP0166190A3 (en) 1986-12-03
EP0166190B1 true EP0166190B1 (de) 1988-03-23

Family

ID=6239232

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85106182A Expired EP0166190B1 (de) 1984-06-27 1985-05-21 Reinigungsvorrichtung für Regenerativ-Wärmetauscher

Country Status (8)

Country Link
US (1) US4705057A (ja)
EP (1) EP0166190B1 (ja)
JP (1) JPS6115097A (ja)
CN (1) CN85104615B (ja)
DE (1) DE3423619C2 (ja)
ES (1) ES8609693A1 (ja)
IN (1) IN160618B (ja)
MX (1) MX161261A (ja)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4972804A (en) * 1989-04-25 1990-11-27 Alexander T. Kindling Method and apparatus for organizing the flow of fluid in a vertical steam generator
US5019329A (en) * 1989-12-26 1991-05-28 Westinghouse Electric Corp. System and method for vertically flushing a steam generator during a shock wave cleaning operation
US5336331A (en) * 1992-01-22 1994-08-09 Jenkins Jerry Y Continuous condenser backflush and cleaning systems and methods for use thereof
DE19617860A1 (de) * 1996-04-23 1997-10-30 Buchen Gmbh Richard Sicherheitsvorrichtung für Hochdruckreinigungsgeräte zur Reinigung von Rohrwärmetauschern
US5924478A (en) * 1997-05-08 1999-07-20 Caterpillar Inc. Radiator washing system and method
US6318108B1 (en) 2000-09-27 2001-11-20 George L. Holstein Self-washing coil for air conditioning units
PT2051033E (pt) * 2007-10-17 2010-04-30 Balcke Duerr Gmbh Permutador regenerativo de calor
US20140041692A1 (en) 2012-08-07 2014-02-13 Aquarecycle, Llc Apparatus for cleaning a surface

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE515533A (ja) *
US1858508A (en) * 1925-03-14 1932-05-17 Ljungstroms Angturbin Ab Regenerative heating device
US2355021A (en) * 1941-08-08 1944-08-01 Air Preheater Washing apparatus for air preheaters
FR1186972A (fr) * 1957-04-17 1959-09-04 Svenska Rotor Maskiner Ab Dispositif de nettoyage pour préchauffeur rotatif
DE1143959B (de) * 1957-12-05 1963-02-21 Kraftanlagen Ag Rauchgasbeheizter Regenerativ-Luftvorwaermer mit feststehender Speichermasse und umlaufenden Luftanschluessen
BE879153A (fr) * 1979-10-02 1980-02-01 Sadacem Installation de ramonage de rechauffeurs d'air rotatifs

Family Cites Families (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3123132A (en) * 1964-03-03 Device for fluid cleaning of heat
US987450A (en) * 1910-12-07 1911-03-21 Vulcan Soot Cleaner Company Of Pittsburg Boiler-flue cleaner.
US1095991A (en) * 1913-11-26 1914-05-05 Gordon C Bennett Blower for boilers.
US1116873A (en) * 1914-03-10 1914-11-10 William L Cronin Boiler-flue blower.
US1141304A (en) * 1915-02-01 1915-06-01 James C Bennett Blower for boilers.
GB160588A (en) * 1920-01-20 1921-03-31 Harry Francis Jackson Thompson Cleaning condenser tubes and the like
US1939153A (en) * 1932-02-23 1933-12-12 Armando S Villasuso Regenerative heater
US2236635A (en) * 1940-01-03 1941-04-01 Jay A Young Apparatus for cleaning preheaters
NL103708C (ja) * 1940-11-21
US2379506A (en) * 1943-08-13 1945-07-03 Air Preheater Rotor operated washing nozzle
US2668978A (en) * 1951-02-07 1954-02-16 Diamond Power Speciality Retractable soot blower of the long-travel trolley supported type
US2812923A (en) * 1954-03-11 1957-11-12 Air Preheater Preheater washing device
US3183961A (en) * 1960-09-08 1965-05-18 Brandt Herbert Method and apparatus for controlling the temperature and humidity of a regenerative air-heater
US3208971A (en) * 1962-06-04 1965-09-28 Dow Corning Bis-silyl ureas and copolymers thereof
US3233661A (en) * 1962-11-16 1966-02-08 Svenska Rotor Maskiner Ab Flue gas heated regenerative air preheater with stationary heat retaining mass and rotary air channel valves
DE1904117U (de) * 1964-08-04 1964-11-12 Appbau Rothemuehle Brandt & Kr Russblaeser fuer regenerativ-lufterhitzer mit umlaufenden lufthauben und stationaeren heizflaechen.
GB1160439A (en) * 1965-09-21 1969-08-06 Jean Eugene Julien Dulait Improvements to Soot Blowing Devices.
US3576033A (en) * 1967-05-22 1971-04-20 Stevens & Co Inc J P 1-methyl-phenylene-2,4-bis(triethoxysilyl propylene-3'-ureylene)
US3595250A (en) * 1968-04-12 1971-07-27 Malsbary Mfg Co Automatic carwash apparatus
US3493461A (en) * 1969-01-21 1970-02-03 Union Carbide Corp Glass fiber reinforced polyvinyl chloride resin article and process therefor
US4046794A (en) * 1972-04-14 1977-09-06 Union Carbide Corporation Urea silicon product and uses thereof
GB1559679A (en) * 1975-11-04 1980-01-23 Davidson & Co Ltd Regenerative air preheaters and seal frame suspension control system therefor
IT1069399B (it) * 1976-12-23 1985-03-25 Autelli Giulio Lancia multipla pluriugelli per il lavaggio di scambiatori di calore rotanti e distributore per dette lance
SE422711B (sv) * 1978-05-19 1982-03-22 Frigoscandia Contracting Ab Sett att under drift avlegsna frostbeleggningar fran kylbatterier samt anordning for genomforande av settet
US4296780A (en) * 1978-06-21 1981-10-27 A. B. Carl Munters Apparatus including throttling device for use in ventilation duct
JPS5657792A (en) * 1979-10-15 1981-05-20 Shin Etsu Chem Co Ltd Preparation of ureido group-containing alkoxysilane
NL183026C (nl) * 1980-11-25 1988-07-01 Ppg Industries Inc Waterig appreteermiddel voor glasvezels, werkwijze voor de bereiding daarvan, de verkregen glasvezels en de met deze vezels gevormde polymeren.
US4428417A (en) * 1981-12-09 1984-01-31 Chesner Ramon J Heat exchanger cleaner
JPS5952199A (ja) * 1982-09-20 1984-03-26 Nippon Furekuto Kk 清掃機能を備えた回転式熱交換器
US4542785A (en) * 1983-09-23 1985-09-24 Massey-Ferguson Industries Limited Agricultural harvester heat exchanger

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE515533A (ja) *
US1858508A (en) * 1925-03-14 1932-05-17 Ljungstroms Angturbin Ab Regenerative heating device
US2355021A (en) * 1941-08-08 1944-08-01 Air Preheater Washing apparatus for air preheaters
FR1186972A (fr) * 1957-04-17 1959-09-04 Svenska Rotor Maskiner Ab Dispositif de nettoyage pour préchauffeur rotatif
DE1143959B (de) * 1957-12-05 1963-02-21 Kraftanlagen Ag Rauchgasbeheizter Regenerativ-Luftvorwaermer mit feststehender Speichermasse und umlaufenden Luftanschluessen
BE879153A (fr) * 1979-10-02 1980-02-01 Sadacem Installation de ramonage de rechauffeurs d'air rotatifs

Also Published As

Publication number Publication date
MX161261A (es) 1990-08-24
CN85104615A (zh) 1986-12-10
US4705057A (en) 1987-11-10
EP0166190A3 (en) 1986-12-03
EP0166190A2 (de) 1986-01-02
DE3423619C2 (de) 1986-09-04
JPS6115097A (ja) 1986-01-23
ES544528A0 (es) 1986-07-16
DE3423619A1 (de) 1986-01-02
IN160618B (ja) 1987-07-18
CN85104615B (zh) 1988-01-06
ES8609693A1 (es) 1986-07-16
JPH0373799B2 (ja) 1991-11-22

Similar Documents

Publication Publication Date Title
DE2247400C2 (de) Vorrichtung zum Abblasen von verdichteter Luft aus einem Verdichter eines Gasturbinenstrahltriebwerks
CH680114A5 (ja)
DE1621561B2 (de) Vorrichtung zum reinigen von speicherplatten
EP0166190B1 (de) Reinigungsvorrichtung für Regenerativ-Wärmetauscher
DE4005208A1 (de) Vorrichtung zur durchfuehrung eines dragier und/oder filmueberzugsverfahrens
DE2826596C2 (de) Stopfrohranordnung an einer Wurstfüllmaschine
DE1079667B (de) Reinigungsvorrichtung fuer schwer zugaengliche Hohlraeume, insbesondere fuer die Behaelter von Tankwagen
DE2348265A1 (de) Vorrichtung zur abtastung einer gekruemmten flaeche
DE2327532C3 (de) Flüssigkeitsfilter mit selbsttätiger Reinigung
DE2144896A1 (de) Kassette und Antriebswelle zum Aufnehmen der Kassette
DE2642004C2 (de) Dünnschichtverdampfer
DD202242A5 (de) Verfahren und einrichtung zum transport von zigaretten
EP0352570A1 (de) Vorrichtung zur Oberflächenbehandlung und insbesondere zur Reinigung von Fussböden und dergleichen
DE19854704C1 (de) Halte- und Reinigungsvorrichtung für zylindrische Filter
DE2238328A1 (de) Maschine zum ausbringen von gekoerntem oder pulverfoermigem material
DE4244038C1 (de) Vorrichtung zum streifen- oder tropfenförmigen Ausbringen fließfähiger Massen
DE2558946C2 (de) Verfahren zum Aufbringen eines Überzugs auf lose Teile und Vorrichtung zur Durchführung des Verfahrens
DE3543234C2 (ja)
DE2334840B1 (de) Kraftfahrzeug-Trocknungsanlage
DE3404057A1 (de) Verfahren und vorrichtung zum aneinanderbefestigen von rohrstuecken mit im winkel zueinanderstehenden rohrwaenden
DE2852446A1 (de) Duesenreinigungsvorrichtung
DE3806004A1 (de) Reinigungsgeraet fuer einen waermetauscher
DE19533071C2 (de) Vorrichtung zur Reinigung von Einbauten in wärme- und/oder verfahrenstechnischen Apparaten
DE1577712A1 (de) Abgedichtete Vorrichtung zur Ausfuehrung einer kreisfoermigen Bewegung zum Be- oder UEberstreichen von Gegenstaenden
DE4323490A1 (de) Transportvorrichtung mit einer Mitnehmerkette

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

AK Designated contracting states

Designated state(s): GB IT NL

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): GB IT NL

17P Request for examination filed

Effective date: 19861113

17Q First examination report despatched

Effective date: 19870304

D17Q First examination report despatched (deleted)
GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): GB IT NL

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
ITF It: translation for a ep patent filed

Owner name: ING. ZINI MARANESI & C. S.R.L.

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

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19910415

Year of fee payment: 7

ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19910531

Year of fee payment: 7

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

Ref country code: GB

Effective date: 19920521

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

Ref country code: NL

Effective date: 19921201

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19920521