Global Patent Index - EP 1050342 A1

EP 1050342 A1 2000-11-08 - Method for removing impurities from an aqueous paper fiber suspension

Title (en)

Method for removing impurities from an aqueous paper fiber suspension

Title (de)

Verfahren zur Entfernung von Störstoffen aus einer wässrigen Papierfasersuspension

Title (fr)

Procédé pour éliminer des impuretés d'une suspension aqueuse de fibres à papier

Publication

EP 1050342 A1 (DE)

Application

EP 00107633 A

Priority

DE 19920480 A

Abstract (en)

Selective flotation stages (1,2) are used to separate foreign matter from a fiber suspension (S). The downstream flotation s (2) uses the residual air contained in the cleaned suspension flow (A1) from the first stage (1), without additional air to give bubbles for flotation. The second and downstream stage (2) acts as a flotation cyclone, with a centrifugal acceleration of the hydrocyclone of a v which is 5-200 times the rate of the spin of the earth, or 10-100 times. At the second and downstream flotation stage (2), the suspension from the first stage (1) is fed at a tangent into a cylinder. The flotation foam (R2) formed at the second stage (2) the cleaned suspension (A2) move out of the stage (2) at the axially opposite end to the inlet. The flotation foam (R2) is taken axially from the side of the second flotation stage (2) which also has the inflow, and the cleaned suspension (A2) is taken axia from the opposite side. The weaker force field used is the gravity of the earth. The cleaned suspension (A1) from the first flotation stage (1) is passed directly to the downstream flotation stage (2), without dwelling in a vat.

Abstract (de)

Das Verfahren dient der Entfernung von Störstoffen, z.B. Druckfarben oder Stickies, aus einer wässrigen Papierfasersuspension, insbesondere wenn diese aus Altpapier hergestellt ist. Es werden mehrere selektive Flotationsschritte durchgeführt, von denen der stromaufwärtige Flotationsschritt (1), z.B. im Erdschwerefeld betrieben wird und der unmittelbar stromabwärts folgende Flotationsschritt (2) in einem Flotationszyklon. Dabei wird der Flotationszyklon lediglich mit Hilfe der im Gutstoff (A1) des stromaufwärtigen Flotationsschrittes (1) enthaltenen Restluft, also ohne weitere Luftzugabe betrieben. Das Verfahren ist besonders wirtschaftlich und effektiv. <IMAGE>

IPC 1-7 (main, further and additional classification)

B03D 1/02; B03D 1/14; D21F 1/70

IPC 8 full level (invention and additional information)

B03D 1/02 (2006.01); B03D 1/14 (2006.01); D21F 1/70 (2006.01)

CPC (invention and additional information)

B03D 1/1418 (2013.01); B03D 1/02 (2013.01); B03D 1/1406 (2013.01); B03D 1/1462 (2013.01); B03D 1/1475 (2013.01); B03D 1/247 (2013.01); D21F 1/70 (2013.01)

Citation (search report)

  • [DYA] EP 0888819 A1 19990107 - VOITH SULZER PAPIERTECH PATENT [DE]
  • [DA] DE 4426159 A1 19941208 - VOITH GMBH J M [DE]
  • [DY] DATABASE WPI Section Ch Week 8540, Derwent Publications Ltd., London, GB; Class F09, AN 1985-245072 [25], XP002041309

Designated contracting state (EPC)

AT DE FI FR

EPO simple patent family

EP 1050342 A1 20001108; EP 1050342 B1 20060607; AT 328667 T 20060615; DE 19920480 A1 20001109; DE 50012882 D1 20060720

INPADOC legal status


2008-11-28 [PG25 FR] LAPSED IN A CONTRACTING STATE ANNOUNCED VIA POSTGRANT INFORM. FROM NAT. OFFICE TO EPO

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- Free text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

- Effective date: 20060607

2008-08-29 [PG25 AT] LAPSED IN A CONTRACTING STATE ANNOUNCED VIA POSTGRANT INFORM. FROM NAT. OFFICE TO EPO

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

- Effective date: 20070408

2008-04-30 [PG25 FR] LAPSED IN A CONTRACTING STATE ANNOUNCED VIA POSTGRANT INFORM. FROM NAT. OFFICE TO EPO

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- Free text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

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2008-01-31 [PG25 DE] LAPSED IN A CONTRACTING STATE ANNOUNCED VIA POSTGRANT INFORM. FROM NAT. OFFICE TO EPO

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2007-05-16 [26N] NO OPPOSITION FILED

- Effective date: 20070308

2007-05-04 [EN] FR: TRANSLATION NOT FILED

2006-09-13 [RAP2] TRANSFER OF RIGHTS OF AN EP GRANTED PATENT

- Owner name: VOITH PATENT GMBH

2006-07-20 [REF] CORRESPONDS TO:

- Document: DE 50012882 P 20060720

2006-06-07 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: B1

- Designated State(s): AT DE FI FR

2006-06-07 [PG25 FI] LAPSED IN A CONTRACTING STATE ANNOUNCED VIA POSTGRANT INFORM. FROM NAT. OFFICE TO EPO

- Ref Country Code: FI

- Free text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

- Effective date: 20060607

2001-07-25 [AKX] PAYMENT OF DESIGNATION FEES

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2001-07-04 [17P] REQUEST FOR EXAMINATION FILED

- Effective date: 20010508

2001-04-04 [RAP1] TRANSFER OF RIGHTS OF AN EP PUBLISHED APPLICATION

- Owner name: VOITH PAPER PATENT GMBH

2000-11-08 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A1

- Designated State(s): AT DE FI FR

2000-11-08 [AX] REQUEST FOR EXTENSION OF THE EUROPEAN PATENT TO

- Free text: AL;LT;LV;MK;RO;SI