EP0111825B1 - Dispositif pour la technique de séparation magnétique à gradients forts en vue de séparer des particules magnétisables - Google Patents

Dispositif pour la technique de séparation magnétique à gradients forts en vue de séparer des particules magnétisables Download PDF

Info

Publication number
EP0111825B1
EP0111825B1 EP83112268A EP83112268A EP0111825B1 EP 0111825 B1 EP0111825 B1 EP 0111825B1 EP 83112268 A EP83112268 A EP 83112268A EP 83112268 A EP83112268 A EP 83112268A EP 0111825 B1 EP0111825 B1 EP 0111825B1
Authority
EP
European Patent Office
Prior art keywords
filter
gauzes
filter sub
separating device
medium
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
EP83112268A
Other languages
German (de)
English (en)
Other versions
EP0111825A1 (fr
Inventor
Günter Dr. Rupp
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.)
Siemens AG
Original Assignee
Siemens 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 Siemens AG filed Critical Siemens AG
Publication of EP0111825A1 publication Critical patent/EP0111825A1/fr
Application granted granted Critical
Publication of EP0111825B1 publication Critical patent/EP0111825B1/fr
Expired 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
    • B03C1/00—Magnetic separation
    • B03C1/02—Magnetic separation acting directly on the substance being separated
    • B03C1/025—High gradient magnetic separators
    • B03C1/031—Component parts; Auxiliary operations
    • B03C1/033—Component parts; Auxiliary operations characterised by the magnetic circuit
    • B03C1/034—Component parts; Auxiliary operations characterised by the magnetic circuit characterised by the matrix elements

Definitions

  • the invention relates to a device of the high-gradient magnetic separation technology for separating magnetizable particles from a flowing medium with a filter structure which has a plurality of at least approximately perpendicular to the direction of flow of the medium and viewed in the direction of flow relatively closely arranged wire networks made of non-corrosive, ferromagnetic material contains a predetermined mesh size and thickness of their wires, the wire nets being arranged in a magnetic field directed essentially parallel or antiparallel to the direction of flow of the medium.
  • a separation device is known from DE-PS 26 28 095.
  • the magnetic deposition method takes advantage of the fact that in a suitable magnetic field arrangement a magnetizable particle experiences a force which moves or holds it against other forces acting on it. Such forces are, for example, gravity or hydrodynamic frictional forces in a liquid medium. Separation processes of this type are intended, for example, for steam or cooling water circuits in conventional as well as in nuclear power plants. In the liquid or gaseous medium of these circuits, particles are suspended, which are generally caused by corrosion. When removing these particles from the medium with the aid of a magnetic separation process, however, the difficulty arises that the particles to be separated are very different in their chemical composition, their particle size and their magnetizability.
  • the corrosion products in the secondary circuit of a nuclear power plant consist of various iron oxides, of which the ferrimagnetic magnetite (Fe 3 0 4 ) is the largest, the antiferromagnetic hematite (a-Fe 2 0 3 ) the second largest proportion by weight and paramagnetic hydroxides the rest.
  • a corresponding device contains a cylindrical filter container which is filled with soft iron balls which are arranged in a magnetic field generated by an electrical coil surrounding the filter container.
  • This magnetic field in conjunction with the balls, gives rise to sufficiently high field strength gradients to attach the ferromagnetic particles, which are also transported in a liquid flowing through the filter, to the magnetic poles of the balls.
  • the balls can be demagnetized to clean the filter.
  • the degree of separation of this known device i.e. the ratio of the concentration of suspended matter separated from the spherical filter to the corresponding concentration before entering the filter is relatively small.
  • HGM technology high gradient magnetic separation technology
  • the device to be extracted from the above-mentioned DE-PS 26 28 095 is such an HGM separating device.
  • a central filter space it contains a filter structure made up of a plurality of wire meshes arranged in close succession in the flow direction to form a stack, which are arranged perpendicular to the flow direction of the medium in a relatively strong magnetic field.
  • This magnetic field is directed parallel or antiparallel to the direction of flow of the medium in the area of the filter structure and causes, for example, a magnetic induction in the order of 1 Tesla.
  • the thickness of the wires of the networks made of ferromagnetic material is very small and is, for example, less than 0.1 mm. The magnetic field gradients generated on them are consequently very high, so that even weakly magnetizable particles can be filtered out with this separating device.
  • the object of the present invention is therefore, to improve the above-mentioned separation device so that its degree of separation and their service life are increased.
  • the first filter substructure therefore has the low field strength, and the volume of the easily magnetizable particles is absorbed.
  • the second filter substructure with the high field strength is then reserved for the separation of weakly magnetizable particles.
  • the variation in the wire thickness of the networks of the two filter structures takes into account the fact that the particles to be separated are different with regard to their size and magnetizability. Both measures, namely two or more magnetic field strength ranges and gradation of the wire diameter, lead to a more uniform distribution of the separated particles in the entire filter volume.
  • the advantages associated with this embodiment of the separating device according to the invention can then be seen in particular in a relatively high degree of separation, a slowly increasing pressure drop and in a long service life of the filter structure.
  • the separating device generally designated 2 contains a container 4 which is essentially rotationally symmetrical with respect to an axis 3 and which is made of non-magnetic material such as e.g. made of stainless steel.
  • This, for example, vertically arranged container is closed on its upper end face by means of a flange cover 5 and contains a lateral connecting flange 6 in the region of its lateral surface adjoining it.
  • the lower end of the container is designed as a central flange 7.
  • a medium M, in which the particles to be filtered out are suspended, is to be introduced into the interior 8 of the container through the side connecting flange 6, while the filtered medium, designated M ', is discharged again from the container 4 on the flange 7.
  • Each filter substructure 10 and 11 is composed of a predetermined number of filter elements 12 and 13, for example, which have the same extent in the flow direction, so that the ratio of the number of elements 12 of the filter substructure 10 to the number of elements 13 of the filter substructure 1 is approximately the ratio of 1 corresponds to 1 2 .
  • Each of these filter elements has, for example, a hollow cylindrical holding frame in order to hold a plurality, ie at least 50,
  • the filter elements 12 and 13 preferably to be able to accommodate at least 100 nets arranged in close succession in the flow direction, in particular so-called netting blanks.
  • only one of the filter elements 12 and 13 has a portion of the associated networks coarsened by lines 14 and 15, respectively.
  • the nets consist of the finest wires made of non-corrosive, ferromagnetic material, for example made of stainless steel, and have a predetermined mesh size.
  • the networks are held in the individual filter elements 12, 13 or partial filter structures 10, 11 in such a way that they are arranged in the container 4 perpendicular to the direction of flow of the medium M.
  • Adjacent nets 14 and 15 in the filter elements 12 and 13 are at approximately the same short distance of about one millimeter or lie directly on top of one another.
  • a larger number of nets 14 is accommodated in the filter volume of the first filter substructure 10 in accordance with the ratio 11 to 1 2 than in the filter volume of the second filter substructure 11.
  • the mutual spacing of the nets within a filter element 12, 13 and / or are graduated from filter element to filter element, in which case a greater packing density of nets is generally provided after the outlet side of the respective filter substructure than on the corresponding inlet side.
  • the thickness of the wires of the nets 14 on the inlet side denoted by 16 of the first filter substructure 10 should be greater than the thickness of the wires of the nets 15 on the outlet side denoted by 17 of the second filter substructure 11.
  • the networks 14 of the first filter substructure and / or the networks 15 of the second filter substructure can each have the same wire thicknesses. It is particularly advantageous however, when the wire thickness in each of the filter substructures varies in the flow direction of the medium M in such a way that the coarser wires are arranged at the inlet and the finer ones at the outlet. As a result, it is taken into account in each of the two filter substructures that the particles to be separated can vary with regard to their size and magnetizability.
  • the wire thickness of the nets 14 on the inlet side 16 of the first filter substructure 10 is preferably selected to be at least twice as large as the wire thickness of the last nets 15 on the outlet side 17 of the second filter substructure 11.
  • the nets 14 of all filter elements 12 can have the same wire thickness.
  • the networks 15 of the filter elements 13 the same wire size is chosen, which is smaller by the predetermined amount.
  • the wire thickness in at least one of the filter substructures 10 or 11, for example only in the filter substructure 11, can vary from the stronger to the lesser.
  • the thickness of the wires of the nets 14 of the first filter substructure 1Q is less than 0.4 mm, preferably about 0.2 mm, while wires with a thickness of less than 0.1 mm are provided for the nets 15 of the downstream filter substructure 1Q.
  • the nets 14 of the filter elements 12 and / or the nets 15 of the filter elements 13 can also be graduated in terms of their mesh size in such a way that the nets with the larger mesh size are each arranged on the inlet side and the nets with the smaller mesh size on the outlet side. In general, mesh sizes between 1.0 mm and 0.1 mm are provided for the nets 14 and 15.
  • the first filter substructure 1Q should be exposed to a largely homogeneous magnetic field directed parallel or antiparallel to the direction of flow of the medium M.
  • This magnetic field is generated by a magnetic coil 18 arranged in the area of the filter substructure 10 around the container 4 and in this filter substructure causes a magnetic flux density B 1 indicated by an arrowed line, which is generally between 0.01 Tesla and 0.1 Tesla.
  • the second filter substructure 1 is also enclosed by a magnet coil 19, which is designed for a magnetic flux density B 2 in this filter substructure between approximately 0.1 Tesla and 1.0 Tesla.
  • the flux density B 1 caused by the coil 18 in the filter substructure 10 should be lower, preferably at most half as large as the flux density B 2 generated by the coil 19 in the downstream filter substructure 1.
  • each of these coils is still surrounded by an iron jacket 20 or 21 so that only the side of the coil facing the respective filter substructure remains open.
  • your container 4 made of non-magnetic stainless steel has an inner diameter of about 400 mm and a wall thickness of 5 mm.
  • the first filter substructure 10 is composed over a length 11 of approximately 500 mm of 1000 network blanks 14 of non-corroding, ferromagnetic stainless steel stacked directly on top of one another within 11 filter elements 12.
  • Net blanks 14 with wire thicknesses of 0.2 mm and mesh sizes of approximately 1 mm are provided on the inlet side 16 of the filter substructure 10, while the net blanks 14 made of wires with 0.1 mm thickness and mesh sizes are provided on the outlet side of the filter substructure 10 facing the filter substructure 11 of 0.2 mm.
  • the subordinate filter substructure 11 contains, over a length I 2 of approximately 250 mm, approximately 500 network blanks 15 lying one on top of the other in 6 filter elements 13, which have wire thicknesses of approximately 0.1 mm and mesh sizes of 0.2 mm on the inlet side facing the filter substructure 10 the outlet side 17 mesh blanks 15 with wire thicknesses of 0.05 mm and mesh sizes of 0.1 mm are provided.
  • the values for the wire thicknesses and mesh sizes between the values of the respective inlet and outlet sides are graduated within the two filter substructures 10 and 11.
  • the coil 18 is designed to generate a magnetic flux density B 1 of 0.05 Tesla
  • the coil 19 is designed for a magnetic flux density B 2 of approximately 0.2 Tesla.

Landscapes

  • Filtering Materials (AREA)
  • Liquid Crystal (AREA)
  • Hard Magnetic Materials (AREA)
  • Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
  • Filtration Of Liquid (AREA)

Claims (12)

1. Dispositif de la technique de séparation magnétique à gradients élevés pour réaliser le dépôt de particules magnétisables depuis unfluide en écoulement (M), à l'aide d'une structure de filtre, qui contient plusieurs réseaux de fils (14,15), disposés au moins à peu près perpendiculairement à la direction de l'écoulement et comparativement étroitement serrés les uns derrière les autres, lorsque l'on regarde approximativement dans le sens de l'écoulement, et qui sont constitués en un matériau ferromagnétique nese corrodant pas et possèdent des mailles d'une largeur prédéterminée et des fils d'une épaisseur prédéterminée, les réseaux de fils étant disposés dans un champ magnétique dirigé essentiellement selon une direction parallèle ou antiparallèle par rapport à la direction d'écoulement du fluide, caractérisé par le fait que la structure de filtre contient au moins deux structures partielles (10, 11) disposées l'une derrière l'autre suivant la direction d'écoulement du fluide (M), auquel cas à l'étendue de la première structure partielle de filtre (10) se trouve produite une densité de flux magnétique (B1) qui est inférieure à la densité de flux magnétique (B2) produite à l'etendue de la seconde structure partielle de filtre (11), alors qu'au moins les fils des réseaux (14) possèdent, sur le côté d'entrée (16) du fluide (M) dans la première structure partielle de filtre (10),une épaisseur plus importante que les fils des réseaux (15) au niveau du côté de sortie (17) du fluide (M') hors de la seconde structure partielle de filtre (11).
2. Dispositif de séparation suivant la revendication 1, caractérisé par le fait que la densité de flux magnétique (B2) dans la seconde structure partielle de filtre (11) est égale au moins au double de la densité de flux magnétique (B1) dans la première structure partielle de filtre (10).
3. Dispositif de séparation suivant la revendication 1 ou 2, caractérisé en ce que des réseaux (14) de la première structure partielle de filtre (10) possèdent des fils de même épaisseur.
4. Dispositif de séparation suivant l'une des revendications 1 à 3, caractérisé par le fait que les réseaux (15) de la seconde structure partielle de filtre (11) possèdent des fils de même épaisseur.
5. Dispositif de séparation suivant la revendication 1 ou 2, caractérisé par le fait que l'épaisseur des fils des réseaux (14; 15) de la première et/ou de la seconde structure partielle de filtre (10 ou 11) diminue dans la direction de l'écoulement.
6. Dispositif de séparation suivant l'une des revendications 1 à 5, caractérisé par le fait que dans au moins l'une des structures partielles de filtre (10,11), l'épaisseur des fils des réseaux au niveau du côté entrée est au moins deux fois plus importante que l'épaisseur des fils des réseaux au niveau du côté sortie.
7. Dispositif de séparation suivant l'une des revendications 1 à 6, caractérisé par le fait que le volume occupé par la première structure partielle de filtre (10) est supérieur au volume occupé par la seconde structure partielle de filtre (11).
8. Dispositif de séparation suivant l'une des revendications 1 à 7, caractérisé par le fait que les deux structures partielles de filtre (10, 11) possèdent des nombres différents de réseaux (14 ou 15).
9. Dispositif de séparation suivant l'une des revendications 1 à 8, caractérisé par le fait que les distances entre des réseaux voisins (14; 15) dans la première et/ou dans la seconde structure partielle de filtre (10, 11) possèdent des valeurs différentes.
10. Dispositif de séparation suivant l'une des revendications 1 à 9, caractérisé par le fait que les réseaux (14) de la première structure partielle de filtre (10) et/ou les réseaux (15) de la seconde structure partielle de filtre (11) possèdent respectivement sur le côté entrée des mailles dont la largeur est plus importante que sur le côté sortie.
11. Dispositif de séparation suivant l'une des revendications 1 à 10, caractérisé par le fait qu'au moins quelques uns des réseaux (14) de la première structure partielle de fitre (10) possèdent des mailles d'une largeur plus importante que les réseaux (15) de la seconde structure partielle de filtre (11).
EP83112268A 1982-12-22 1983-12-06 Dispositif pour la technique de séparation magnétique à gradients forts en vue de séparer des particules magnétisables Expired EP0111825B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19823247522 DE3247522A1 (de) 1982-12-22 1982-12-22 Vorrichtung der hochgradienten-magnettrenntechnik zum abscheiden magnetisierbarer teilchen
DE3247522 1982-12-22

Publications (2)

Publication Number Publication Date
EP0111825A1 EP0111825A1 (fr) 1984-06-27
EP0111825B1 true EP0111825B1 (fr) 1986-03-19

Family

ID=6181445

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83112268A Expired EP0111825B1 (fr) 1982-12-22 1983-12-06 Dispositif pour la technique de séparation magnétique à gradients forts en vue de séparer des particules magnétisables

Country Status (4)

Country Link
US (1) US4544482A (fr)
EP (1) EP0111825B1 (fr)
JP (1) JPS59120219A (fr)
DE (2) DE3247522A1 (fr)

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1989011324A1 (fr) * 1988-05-25 1989-11-30 Ukrainsky Institut Inzhenerov Vodnogo Khozyaistva Dispositif pour separer des materiaux ferromagnetiques contenus dans des milieux fluides
US4666595A (en) * 1985-09-16 1987-05-19 Coulter Electronics, Inc. Apparatus for acoustically removing particles from a magnetic separation matrix
US4664796A (en) * 1985-09-16 1987-05-12 Coulter Electronics, Inc. Flux diverting flow chamber for high gradient magnetic separation of particles from a liquid medium
US6020210A (en) * 1988-12-28 2000-02-01 Miltenvi Biotech Gmbh Methods and materials for high gradient magnetic separation of biological materials
DE4328739A1 (de) * 1993-08-26 1995-03-02 Klaus Pflieger Vorrichtung zur Behandlung von Kühlflüssigkeiten
US5439586A (en) * 1993-09-15 1995-08-08 The Terry Fox Laboratory Of The British Columbia Cancer Agnecy Magnetic filter with ordered wire array
US5514340A (en) * 1994-01-24 1996-05-07 Magnetix Biotechnology, Inc. Device for separating magnetically labelled cells
AT404563B (de) * 1997-07-08 1998-12-28 Goeschl Robert Verfahren und vorrichtung zur abscheidung von magnetisierbaren teilchen
GB2330321B (en) * 1997-10-16 2001-09-12 Cryogenic Ltd High gradient magnetic separation
US6238279B1 (en) * 1999-06-03 2001-05-29 Promos Technologies, Inc. Magnetic filtration for slurry used in chemical mechanical polishing of semiconductor wafers
GB0023385D0 (en) * 2000-09-23 2000-11-08 Eriez Magnetics Europ Ltd Magnetic separator
JP5943711B2 (ja) * 2012-05-30 2016-07-05 技研パーツ株式会社 強磁性体フィルタ及びこれを備えた不純物除去器具並びに不純物除去方法
US9598957B2 (en) 2013-07-19 2017-03-21 Baker Hughes Incorporated Switchable magnetic particle filter
WO2017046178A1 (fr) * 2015-09-14 2017-03-23 Medisieve Ltd Appareil de filtration magnétique et procédé
CN106513170B (zh) * 2016-12-22 2018-07-31 河南特耐工程材料股份有限公司 一种螺旋磁场式微粉磁选机
JP7415242B2 (ja) * 2018-03-09 2024-01-17 国立研究開発法人物質・材料研究機構 磁気分離装置

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1277488B (de) * 1967-06-08 1968-09-12 Siemens Ag Einrichtung zur elektromagnetischen Entfernung von Eisenoxyden aus Fluessigkeit
US3567026A (en) * 1968-09-20 1971-03-02 Massachusetts Inst Technology Magnetic device
JPS5245777A (en) * 1975-08-07 1977-04-11 Furukawa Electric Co Ltd:The Magnetic separation apparatus
DE2628095C3 (de) * 1976-06-23 1981-08-06 Siemens AG, 1000 Berlin und 8000 München Magnetische Abscheidevorrichtung
US4087358A (en) * 1976-10-12 1978-05-02 J. M. Huber Corporation Augmenting and facilitating flushing in magnetic separation
JPS54154873A (en) * 1978-05-29 1979-12-06 Nippon Atom Ind Group Co Ltd High-gradient magnetism filter
JPS5524537A (en) * 1978-08-11 1980-02-21 Toshiba Corp Magnetic filter
FR2447744B1 (fr) * 1979-02-02 1988-04-29 British Nuclear Fuels Ltd Procede et appareil de separation de particules d'un liquide
JPS55106510A (en) * 1979-02-09 1980-08-15 Hitachi Ltd Magnetic packed tower

Also Published As

Publication number Publication date
DE3247522A1 (de) 1984-06-28
US4544482A (en) 1985-10-01
EP0111825A1 (fr) 1984-06-27
JPS59120219A (ja) 1984-07-11
DE3362629D1 (en) 1986-04-24

Similar Documents

Publication Publication Date Title
EP0111825B1 (fr) Dispositif pour la technique de séparation magnétique à gradients forts en vue de séparer des particules magnétisables
DE2628095C3 (de) Magnetische Abscheidevorrichtung
EP0050281B1 (fr) Dispositif de séparation pour la technique de séparation à gradients magnétiques élevés
CH657541A5 (de) Verfahren und einrichtung zum trennen magnetischer von unmagnetischen teilchen.
DE2659254A1 (de) Verfahren und vorrichtung zum trennen von teilchen unterschiedlicher dichte mit magnetischen fluiden
WO2016041534A1 (fr) Séparateur magnétique à champ intense
DE2615580C2 (de) Magnetischer Abscheider zum Abscheiden magnetisierbarer Teilchen aus einem durchströmenden Fluid
DE102008047842A1 (de) Vorrichtung und Verfahren zum Abscheiden ferromagnetischer Partikel aus einer Suspension
DE3123229C2 (fr)
DE734137C (de) Dauermagnetfilter zum Abscheiden magnetisierbarer Stoffe aus stroemenden Fluessigkeiten
DE3620660C2 (fr)
DE2624090C2 (de) Magnetischer Abscheider
EP0025095B1 (fr) Dispositif pour la séparation magnétique à gradient élevé
DE3303518C2 (fr)
DE2517857C2 (de) Vorrichtung zum Abscheiden magnetisierbarer Teilchen aus einer Suspension
DE3247557C2 (de) Vorrichtung zur Hochgradienten-Magnetseparation
DE2501858C2 (de) Vorrichtung zum Abscheiden magnetisierbarer Teilchen, die in einer Flüssigkeit suspendiert sind
DE2552355A1 (de) Vorrichtung und verfahren zur scheidung nativer magnetisierbarer teilchen aus einem diese in suspension enthaltenden fluid
DE68922108T2 (de) Vorrichtung zur kontinuierlichen Reinigung von Flüssigkeiten, insbesondere Wasser, durch Hochgradient-Magnetfiltration.
DE3033698A1 (de) Magnetisches filter
DE3427462A1 (de) Magnetische sortiervorrichtung
DE69220930T2 (de) Magnetscheider
DE2738649A1 (de) Vorrichtung fuer filtereinrichtungen zur abscheidung feinster magnetisierbarer teilchen
DE2111986C3 (de) Magnetischer Naßabscheider
DE2615179C3 (de) Magnetscheider

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): DE FR GB

17P Request for examination filed

Effective date: 19840809

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB

REF Corresponds to:

Ref document number: 3362629

Country of ref document: DE

Date of ref document: 19860424

ET Fr: translation filed
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
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19870901

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

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

Effective date: 19880831

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

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

Ref country code: GB

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

Effective date: 19881122