Metso Paper Inc.

Valmet Corporation

Juhana Lumiala

Antti Poikolainen

Ari Puurtinen

Hannu Lepom&auml;ki

Petri Jetsu

Petri Nyberg

Mika Viertola

Hannu Lepomäki

Jarmo Kirvesm&auml;ki

Hannu Karema

Tommi Korolainen

Juha Salmela

Jukka T Heikkinen

Kari Pitk&auml;j&auml;rvi

Jari P H&auml;m&auml;l&auml;inen

Pasi Sirvi&ouml;

Markku Kellom&auml;ki

Ilkka Kemil&auml;inen

A procedure and arrangement to control the lamella of a headbox's lip channel, when the mass flow goes in the headbox () through the lip channel (), in which case single mass flows are held separate from each other with the lamella () before the flows are united after the lamella. The lamella's dimensions, mechanical characteristics and/or dynamic characteristics are changed at least in the lamella's border area with an active structure, which is active and/or passive active tool and/or active and/or passive active material.

Method for managing lamella vibrations of a lip channel of a head box and the lamella for the lip channel of the headbox

A method and an apparatus for mixing dilution liquid into a stock flow in a paper or board machine. Dilution is carried out in at least two stages using in the first dilution stage (I) valves (V , V , V . . . ) fitted with a larger mutual spacing at different points of width across a headbox and passing the dilution water through the valves to desired points of width of the headbox according to the requirement of control of the basis weight of paper or board. In the second dilution stage (II), dilution water is passed into connection with the stock flow coming from the first dilution stage (I), said dilution water being controlled by means of valves (V &prime;, V &prime; . . . ), which valves (V &prime;, V &prime; . . . ) have been fitted with a denser spacing than the valves (V , V , V . . . ) of the first dilution stage (I).

Method for mixing dilution liquid into a stock flow in a paper or board machine to control basis weight using coarse and fine controls

A paper/board machine headbox ( ) has a stock inlet header (J), a tube bank ( ), a turbulence generator ( ) and a slice opening ( ) which is provided with a profile bar. The headbox ( ) is provided with cross direction measuring sensors (D , D ; D ), by means of which the flow rate profile of the headbox ( ) is determined, and the profile bar of the slice opening ( ) of the headbox ( ) is adjusted in the cross direction on the basis of the thus determined flow rate profile. The headbox ( ) is provided with measuring sensors (D , D ; D ) for determining the cross direction flow rate profile of the headbox ( ) and with means for adjusting the profile bar on the basis of the flow rate profile.

Method and system for controlling headbox in a paper/board machine

A headbox ( ) has a stock inlet header, a tube bank, a tubulence generator and a slice channel. Measurement targets (P , P , P , P, P ) are provided with means for making measurements of the fiber mobility of the fiber suspension, then controlling the flow state of the suspension. Sensors on the width of the headbox ( ) or traversing sensors are positioned on different width points of the headbox ( ) and arranged to measure the fiber mobility profile, with means for changing the flow state on the basis of the measurements. Apparatus for diluting the thick stock into headbox consistency and units for cleaning the stock to be fed into the headbox may be provided. Sensors may be disposed in the short circulation pipes or cleaning units arranged to measure the fiber mobility of the fiber suspension with means for changing the flow state on the basis of the measurement data.

Regulation system for the short circulation and headbox of a paper machine or equivalent

A sample collecting device takes samples from the white water drained from the web through the wire in the wire part, at a number of points in the cross direction of the web. An analyzer analyses the samples and forms a retention profile for controlling the paper machine. The device for measurement and regulation of the retention profile comprises means for measurement of the retention profile across the web width from different points of width of the web. The headbox comprises ducts passing to different points of width of the headbox to pass a flow of liquid containing a retention agent in the headbox into connection with the stock flow to regulate the retention profile across the web width. The ducts have valves which are regulated on the basis of the retention profile data for regulating the retention agent into duct flow.

Method and device for measurement of the retention profile and for control of the retention in a paper/board machine

Control equipment for the headbox tip lath of a paper machine includes first actuators ( . . . ), which are located at different points along the headbox ( ) width and connect functionally with a bendable intermediate part ( ). At the different points along the headbox ( ) width there are also second actuators ( . . . ) which are used in the tip lath control. These connect functionally with both the bendable intermediate part ( ) and the tip lath ( ). The first actuators ( . . . ) are used to perform rough control of the tip lath ( ) whereas the second actuators ( . . . ) are used to perform fine control of the tip lath ( ).

Control equipment for the headbox tip lath in a paper machine or such and method of tip lath control

The invention relates to a headbox ( ) for a paper/boardmaking machine. The headbox ( ) including a stock flow header ( ) and, following the stock flow header, a piping system such as an inlet pipe manifold, and/or a turbulence generator ( ) and a tapered slice ( ), wherefrom the stock is passed onto the forming wire (H ). The construction of said headbox further includes a flow header (J) for a dilution liquid the flow header having connected thereto an inlet channel (S ), a return pipe (S ) and outlet channels (D , D , D , . . . ) that are distributed over the full length of said flow channel for passing the dilution water to control valves (V , V , . . . ) and, therefrom, further to different points along the cross-machine width of the headbox so as to mix with the stock delivered from the stock flow header ( ) in order to control the consistency of the stock to a desired value, thus accomplishing the control of the web basis weight profile in cross-machine direction over the headbox. The dilution water flow header (J) is structured to accomplish mixing of the dilution water flow (L ) so as to make the consistency of the dilution water flow (L ) homogeneous both along the entire length of the flow header (J) and in cross sections of the flow taken in planes perpendicular to the longitudinal axis of the flow header.

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Jyväskylä, Finland

Juhana Lumiala