EP0241817B1 - Verfahren und Vorrichtung zur Erzeugung von Stickstoff - Google Patents

Verfahren und Vorrichtung zur Erzeugung von Stickstoff Download PDF

Info

Publication number
EP0241817B1
EP0241817B1 EP87104899A EP87104899A EP0241817B1 EP 0241817 B1 EP0241817 B1 EP 0241817B1 EP 87104899 A EP87104899 A EP 87104899A EP 87104899 A EP87104899 A EP 87104899A EP 0241817 B1 EP0241817 B1 EP 0241817B1
Authority
EP
European Patent Office
Prior art keywords
rectification
nitrogen
air
sub
stream
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
EP87104899A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0241817A3 (en
EP0241817A2 (de
Inventor
Karl-Heinz Dipl.-Ing. Schweigert
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.)
Linde GmbH
Original Assignee
Linde GmbH
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 Linde GmbH filed Critical Linde GmbH
Publication of EP0241817A2 publication Critical patent/EP0241817A2/de
Publication of EP0241817A3 publication Critical patent/EP0241817A3/de
Application granted granted Critical
Publication of EP0241817B1 publication Critical patent/EP0241817B1/de
Expired legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/044—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a single pressure main column system only
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
    • F25J3/04284—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams
    • F25J3/0429—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams of feed air, e.g. used as waste or product air or expanded into an auxiliary column
    • F25J3/04296—Claude expansion, i.e. expanded into the main or high pressure column
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2200/00—Processes or apparatus using separation by rectification
    • F25J2200/50—Processes or apparatus using separation by rectification using multiple (re-)boiler-condensers at different heights of the column
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2200/00—Processes or apparatus using separation by rectification
    • F25J2200/72—Refluxing the column with at least a part of the totally condensed overhead gas
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S62/00—Refrigeration
    • Y10S62/939—Partial feed stream expansion, air

Definitions

  • the invention relates to a process for the production of nitrogen by low-temperature rectification of air, in which the air is compressed and divided into two substreams, the first of which is cooled and fed to a one-stage rectification, while the second is post-compressed, cooled, decompressed and also rectified is supplied, and in which the nitrogen is removed from an upper portion of the rectification.
  • the invention also relates to a device for performing such a method.
  • the publication shows a process for obtaining oxygen of medium purity, a nitrogen stream having essentially atmospheric pressure being obtained, in particular in the exemplary embodiment according to FIG. 2.
  • the first, non-post-compressed partial air stream is fed into the rectification column immediately after it has cooled, while the second, post-compressed partial stream, after it has cooled, is brought out of the rectification in heat exchange with decomposition products and then throttled, before it is also released is passed into the rectification column.
  • a nitrogen stream is removed from the top of the rectification column and is expanded to approximately atmospheric pressure while performing work. The majority of the work performed in relieving nitrogen is transferred to the secondary compressor for the second partial air flow.
  • This method has the disadvantage that the nitrogen obtained with a pressure of approx. 3.3 bar must be expanded in order to drive the air post-compressor. If nitrogen is desired by the consumer at elevated pressure, the nitrogen must be compressed from atmospheric pressure to the desired pressure. If the nitrogen obtained from the rectification with increased pressure is released to the consumer without prior relaxation, additional energy must be used for the post-compression of the second partial air stream, which is also uneconomical.
  • the present invention is therefore based on the object of developing a process for the production of nitrogen of the type mentioned at the outset, with which nitrogen can be obtained economically with superatmospheric pressure.
  • This object is achieved in that the first (not post-compressed) partial stream, before it is fed to the rectification, is brought into heat exchange with bottom liquid from the rectification, that the expansion of the second partial stream is carried out in a work-performing manner and that at least a part of the at Relaxation work is used to recompress the second partial stream.
  • the non-post-compressed partial air stream is used according to the invention for heating the column sump. Heating the sump increases the oxygen content in the sump. At the same time, the nitrogen content in the top of the rectification column increases, so that a high yield is ensured.
  • the entire second partial air stream, which is no longer used to heat the column sump, as in the previously known method, is relaxed after its compression, whereby the work done during the expansion is at least partially transferred to the secondary compressor for the second partial air stream. As a result, it is no longer necessary to relax the nitrogen obtained in the rectification to drive the secondary compressor.
  • the nitrogen can be removed as product directly under the increased pressure of the rectification.
  • the nitrogen is obtained at a pressure between 3 and 10 bar.
  • the nitrogen pressure is preferably between 3 and 6 bar.
  • the second partial flow before its expansion has a higher temperature than the first partial flow before its heat exchange with the bottom liquid.
  • bottom liquid from the rectification in heat exchange with at least partially condensing nitrogen in the head of the rectification is evaporated and the resulting residual gas is used to regenerate a cleaning stage for the air to be separated.
  • the air is preferably cleaned in molecular sieves, which are regenerated with the residual gas, or at least a partial stream thereof.
  • a device for producing nitrogen by low-temperature rectification of air with a rectification column which is connected to a supply line for air to be separated, a branch line containing a compressor and an expansion device branching off from the supply line and also opening into the rectification column, is characterized in that that a heat exchanger is arranged in the branch line, which is in heat-exchanging connection with the bottom of the rectification column.
  • the heat exchanger can be arranged outside the rectification column, its heating surfaces being connected on the one hand to the bottom liquid and on the other hand to the gas space above the liquid. According to a preferred embodiment of the subject of the invention the heat exchanger is arranged in the bottom of the rectification column.
  • FIG. 1 shows a schematic representation of a method for generating nitrogen under elevated pressure.
  • Air 1 to be separated is compressed in a compressor 2 from about 1 bar to 6 bar.
  • the compressed air is fed to a cleaning stage 3, in which impurities, in particular water and carbon dioxide, contained in the air are removed.
  • Cleaning stage 3 is preferably a periodically operated molecular sieve, which is alternately loaded and regenerated.
  • the cleaned air is divided into two partial streams 4, 5.
  • the first partial flow 5, which amounts to about 40% of the air to be separated, is cooled in a heat exchanger 6 in heat exchange with decomposition products to about 100 K and then in a heat exchanger 10, which is arranged in the bottom liquid 11 of a rectification column 7, in heat exchange cooled with the partially evaporating bottom liquid 11 and at least partially liquefied before it is introduced into the rectification column 7.
  • the second partial stream 4 (about 60% of the air to be separated) is post-compressed in a post-compressor 8 to a pressure of about 7 bar and then also cooled in the heat exchanger 6 in heat exchange with decomposition products.
  • the second partial flow 4 is removed from the heat exchanger 6 at an intermediate point. Its temperature is about 120 K and is therefore higher than the temperature of the first partial flow when it is removed from the heat exchanger 6.
  • the second partial flow is then expanded in a turbine 9 to produce a pressure of approximately 4 bar and passed into the rectifying column 7.
  • the premature removal of the second partial flow from the heat exchanger 6 ensures that no expansion into the wet steam region takes place in the turbine 9.
  • the work obtained on the turbine 9 is completely transferred to the post-compressor 8.
  • the air is broken down into an oxygen-rich liquid 11, which collects in the bottom of the rectification column, and a nitrogen-rich gas fraction, which collects in the top of the rectification column.
  • the nitrogen is removed via a line 17 from the top of the rectification column 7 with a purity of approximately 99.9999% and heated in the heat exchanger 6 in heat exchange with the two partial air streams 4, 5 before it is withdrawn from the system.
  • the pressure of the nitrogen obtained (apart from pressure losses when passing through the heat exchanger 6) is equal to the pressure in the rectification column 7.
  • Oxygen-rich liquid is removed from the bottom of the rectification column 7 via a line 12 and, after supercooling in a heat exchanger 13, is fed to a condenser-evaporator in the top of the rectification column 7.
  • the oxygen-rich liquid is evaporated there in heat exchange with condensing nitrogen, which trickles back into the rectification column as reflux liquid.
  • the resulting residual gas is removed via a line 14 and, after heating in the heat exchanger 13, the heat exchanger 6, where it is further heated in heat exchange with the partial air streams 4, 5.
  • Part of the residual gas (line 15) is withdrawn from the system, another part (line 16) is fed to cleaning stage 2 as regeneration gas.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Separation By Low-Temperature Treatments (AREA)
  • Treating Waste Gases (AREA)
EP87104899A 1986-04-02 1987-04-02 Verfahren und Vorrichtung zur Erzeugung von Stickstoff Expired EP0241817B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3610973 1986-04-02
DE19863610973 DE3610973A1 (de) 1986-04-02 1986-04-02 Verfahren und vorrichtung zur erzeugung von stickstoff

Publications (3)

Publication Number Publication Date
EP0241817A2 EP0241817A2 (de) 1987-10-21
EP0241817A3 EP0241817A3 (en) 1987-11-19
EP0241817B1 true EP0241817B1 (de) 1989-11-02

Family

ID=6297715

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87104899A Expired EP0241817B1 (de) 1986-04-02 1987-04-02 Verfahren und Vorrichtung zur Erzeugung von Stickstoff

Country Status (4)

Country Link
US (1) US5037462A (no)
EP (1) EP0241817B1 (no)
DE (2) DE3610973A1 (no)
NO (1) NO167064C (no)

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3770772D1 (de) * 1986-11-24 1991-07-18 Boc Group Plc Luftverfluessigung.
GB2198513B (en) * 1986-11-24 1990-09-19 Boc Group Plc Air separation
JP2755953B2 (ja) * 1988-05-19 1998-05-25 テイサン株式会社 窒素ガス製造方法
DE4017410A1 (de) * 1989-06-02 1990-12-06 Hitachi Ltd Verfahren und vorrichtung zur herstellung von extrem reinem stickstoff
US4966002A (en) * 1989-08-11 1990-10-30 The Boc Group, Inc. Process and apparatus for producing nitrogen from air
US5074898A (en) * 1990-04-03 1991-12-24 Union Carbide Industrial Gases Technology Corporation Cryogenic air separation method for the production of oxygen and medium pressure nitrogen
US5123946A (en) * 1990-08-22 1992-06-23 Liquid Air Engineering Corporation Cryogenic nitrogen generator with bottom reboiler and nitrogen expander
JP2909678B2 (ja) * 1991-03-11 1999-06-23 レール・リキード・ソシエテ・アノニム・プール・レテュード・エ・レクスプロワタシオン・デ・プロセデ・ジョルジュ・クロード 圧力下のガス状酸素の製造方法及び製造装置
JP3306517B2 (ja) * 1992-05-08 2002-07-24 日本酸素株式会社 空気液化分離装置及び方法
FR2692664A1 (fr) * 1992-06-23 1993-12-24 Lair Liquide Procédé et installation de production d'oxygène gazeux sous pression.
FR2700205B1 (fr) * 1993-01-05 1995-02-10 Air Liquide Procédé et installation de production d'au moins un produit gazeux sous pression et d'au moins un liquide par distillation d'air.
US5365741A (en) * 1993-05-13 1994-11-22 Praxair Technology, Inc. Cryogenic rectification system with liquid oxygen boiler
US5385024A (en) * 1993-09-29 1995-01-31 Praxair Technology, Inc. Cryogenic rectification system with improved recovery
US5697229A (en) * 1996-08-07 1997-12-16 Air Products And Chemicals, Inc. Process to produce nitrogen using a double column plus an auxiliary low pressure separation zone
US5682762A (en) * 1996-10-01 1997-11-04 Air Products And Chemicals, Inc. Process to produce high pressure nitrogen using a high pressure column and one or more lower pressure columns
FR2767317B1 (fr) * 1997-08-14 1999-09-10 Air Liquide Procede de conversion d'un debit contenant des hydrocarbures par oxydation partielle
DE19908451A1 (de) * 1999-02-26 2000-08-31 Linde Tech Gase Gmbh Zweisäulensystem zur Tieftemperaturzerlegung von Luft

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0144430A1 (en) * 1983-03-08 1985-06-19 Daidousanso Co., Ltd. Apparatus for producing high-purity nitrogen gas

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB985068A (en) * 1960-04-11 1965-03-03 British Oxygen Co Ltd Separation of air
DE1117616B (de) * 1960-10-14 1961-11-23 Linde Eismasch Ag Verfahren und Einrichtung zum Gewinnen besonders reiner Zerlegungsprodukte in Tieftemperaturgaszerlegungsanlagen
US3620032A (en) * 1968-05-16 1971-11-16 Air Liquide Method for producing high-purity oxygen from commercially pure oxygen feed-stream
FR2060184B1 (no) * 1969-09-10 1973-11-16 Air Liquide
GB1576910A (en) * 1978-05-12 1980-10-15 Air Prod & Chem Process and apparatus for producing gaseous nitrogen
DE2854508C2 (de) * 1978-12-16 1981-12-03 Linde Ag, 6200 Wiesbaden Verfahren und Vorrichtung zur Tieftemperaturzerlegung eines Gasgemisches
DE3035844A1 (de) * 1980-09-23 1982-05-06 Linde Ag, 6200 Wiesbaden Verfahren und vorrichtung zur gewinnung von sauerstoff mittlerer reinheit
US4401188A (en) * 1981-04-06 1983-08-30 C. L. Frost & Son, Inc. Chain spraying apparatus
JPS58198677A (ja) * 1982-05-14 1983-11-18 株式会社日立製作所 空気分離方法及び装置
US4566887A (en) * 1982-09-15 1986-01-28 Costain Petrocarbon Limited Production of pure nitrogen
US4594085A (en) * 1984-11-15 1986-06-10 Union Carbide Corporation Hybrid nitrogen generator with auxiliary reboiler drive

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0144430A1 (en) * 1983-03-08 1985-06-19 Daidousanso Co., Ltd. Apparatus for producing high-purity nitrogen gas

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Hansen/Linde, "Tieftemperaturtechnik", S. 282/283 *

Also Published As

Publication number Publication date
NO167064C (no) 1991-09-25
DE3760920D1 (en) 1989-12-07
DE3610973A1 (de) 1987-10-08
NO167064B (no) 1991-06-17
US5037462A (en) 1991-08-06
NO871365D0 (no) 1987-04-01
EP0241817A3 (en) 1987-11-19
EP0241817A2 (de) 1987-10-21
NO871365L (no) 1987-10-05

Similar Documents

Publication Publication Date Title
EP0241817B1 (de) Verfahren und Vorrichtung zur Erzeugung von Stickstoff
EP0093448B1 (de) Verfahren und Vorrichtung zur Gewinnung von gasförmigem Sauerstoff unter erhöhtem Druck
EP0299364B1 (de) Verfahren und Vorrichtung zur Luftzerlegung durch Rektifikation
EP0505812B1 (de) Verfahren zur Tieftemperaturzerlegung von Luft
DE2557453C2 (de) Verfahren zur Gewinnung von gasförmigem Sauerstoff
DE2920270C2 (de) Verfahren zum Erzeugen von Sauerstoff
EP0316768B1 (de) Verfahren zur Luftzerlegung durch Tieftemperaturrektifikation
EP1031804B1 (de) Tieftemperaturzerlegung von Luft mit Stickstoff Rückführung
DE1007345B (de) Verfahren zum Zerlegen von verdichteter Luft durch Tiefkuehlen, Verfluessigen und Rektifizieren und Vorrichtung fuer das Verfahren
DE3817244A1 (de) Verfahren zur tieftemperaturzerlegung von luft
EP0100923A1 (de) Verfahren und Vorrichtung zur Zerlegung eines Gasgemisches
DE19908451A1 (de) Zweisäulensystem zur Tieftemperaturzerlegung von Luft
DE3528374A1 (de) Verfahren und vorrichtung zur erzeugung von stickstoff mit ueberatmosphaerischem druck
DE19909744A1 (de) Zweisäulensystem zur Tieftemperaturzerlegung von Luft
WO1998019122A1 (de) Verfahren und vorrichtung zur gewinnung von druckstickstoff
DE915456C (de) Verfahren zur Trennung von Gasgemischen in der Kaelte durch Verfluessigung und Rektifikation
DE19537913A1 (de) Dreifachsäulenverfahren zur Tieftemperaturzerlegung von Luft
DE2903089A1 (de) Verfahren zur gewinnung von sauerstoff aus luft
DE4030749A1 (de) Verfahren zur tieftemperaturzerlegung von luft
DE3643359C2 (de) Verfahren und Vorrichtung zur Luftzerlegung durch zweistufige Rektifikation
EP0878677A1 (de) Verfahren und Vorrichtung zur Gewinnung von Stickstoff durch Tieftemperaturzerlegung von Luft
DE19543953C1 (de) Verfahren und Vorrichtung zur Gewinnung von Sauerstoff und Stickstoff unter überatmosphärischem Druck
DE3315930A1 (de) Verfahren und vorrichtung zur zerlegung eines gasgemisches
EP1209431B1 (de) Verfahren und Vorrichtung zur Erzeugung von Sauerstoff und Stickstoff
EP0559117B1 (de) Verfahren und Vorrichtung zur Zerlegung eines Gasgemisches

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

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE GB NL

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE GB NL

17P Request for examination filed

Effective date: 19871027

17Q First examination report despatched

Effective date: 19880728

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE GB NL

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
REF Corresponds to:

Ref document number: 3760920

Country of ref document: DE

Date of ref document: 19891207

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: NL

Payment date: 19910430

Year of fee payment: 5

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19910516

Year of fee payment: 5

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19920320

Year of fee payment: 6

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

Ref country code: NL

Effective date: 19921101

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19930101

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

Ref country code: GB

Effective date: 19930402

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19930402