Global Patent Index - EP 1033437 A3

EP 1033437 A3 2001-03-21 - Method and device for controlling the breaking length ratio in a paper machine

Title (en)

Method and device for controlling the breaking length ratio in a paper machine

Title (de)

Verfahren und Vorrichtung zur Regelung des Reisslängenverhältnisses in einer Papiermaschine

Title (fr)

Procédé et dispositif de régulation de proportion de longeur de rupture dans une machine à papier

Publication

EP 1033437 A3 (DE)

Application

EP 99118682 A

Priority

DE 19908973 A

Abstract (en)

[origin: EP1033437A2] To set the breaking length ratio of a paper web, at a papermaking machine, the actual breaking length ratio is measured at the web formed from a wet pulp delivered by the stock inlet (1), which is compared with a nominal breaking length ratio. The deviation between actual and nominal values is used to adjust the micro-turbulence at the stock inlet delivery opening. The stock inlet has at least one dividing blade, which has a sliding movement to set the level of micro-turbulence. The breaking length ratio is measured by an ultrasonic system. The measurements are made as a lateral profile, and the micro-turbulence is adjusted by sections across the machine width. The measurements are made at a number of points (5.1-5.3) across the machine width, where at least one of the measurement points can be moved by sliding across the machine line. The value of the micro-turbulence alteration is proportional to the absolute difference between the actual and nominal breaking length ratios, where the micro-turbulence is reduced on a low breaking length ratio, and vice versa. The sliding blade is moved along the machine running when the breaking length ratio is too large, and against the machine direction if it is too small. At the same time that the micro-turbulence is adjusted, a modification is made to the difference between the speed of pulp flow from the stock inlet and the fourdrinier movement speed. An Independent claim is included for a papermaking machine with a stock inlet (1) and at least one system to modify the micro-turbulence in the emerging pulp flow. Measurement points (5.1-5.3) to register the breaking length ratio are across the machine width, linked to a unit (9) which compares actual and nominal breaking length ratio values and shows a deviation between them. A control unit (13) sets the intensity of the micro-turbulence at the outflow from the stock inlet, according to the required correction to bring the nominal and actual values together. Preferred Features: The evaluation unit (9) has a suitable program for the comparison of nominal and actual breaking length ratio values, and register a deviation between them. At least one setting system at the stock inlet is in sections, for an adjustment to the intensity of the micro-turbulence by sections across the machine width.

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

D21G 9/00; D21F 1/02

IPC 8 full level (invention and additional information)

D21F 1/02 (2006.01); D21G 9/00 (2006.01)

CPC (invention and additional information)

D21G 9/0027 (2013.01); D21F 1/02 (2013.01); D21F 1/028 (2013.01); Y10S 162/10 (2013.01); Y10S 162/11 (2013.01)

Citation (search report)

Designated contracting state (EPC)

AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

EPO simple patent family

EP 1033437 A2 20000906; EP 1033437 A3 20010321; DE 19908973 A1 20000907; US 6251225 B1 20010626; US 6536443 B1 20030325

INPADOC legal status


2006-05-17 [18D] DEEMED TO BE WITHDRAWN

- Effective date: 20051108

2001-12-12 [AKX] PAYMENT OF DESIGNATION FEES

- Free text: AT DE FI SE

2001-11-14 [17P] REQUEST FOR EXAMINATION FILED

- Effective date: 20010921

2001-03-21 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A3

- Designated State(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

2001-03-21 [AX] REQUEST FOR EXTENSION OF THE EUROPEAN PATENT TO

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

2000-12-20 [RAP1] TRANSFER OF RIGHTS OF AN EP PUBLISHED APPLICATION

- Owner name: VOITH PAPER PATENT GMBH

2000-09-06 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A2

- Designated State(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

2000-09-06 [AX] REQUEST FOR EXTENSION OF THE EUROPEAN PATENT TO

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