Metso Paper Inc.

Hannu Karema

Petri Nyberg

Juhana Lumiala

Hannu Lepomäki

Maarit Tukiainen

Juha Salmela

Petri Jetsu

Hannu Lepom&auml;ki

Markku Kellom&auml;ki

Markku Kellomäki

A method for fluidisation of a pulp flow in the headbox of a paper machine or such. The characteristics of the pulp flow are affected in the headbox's fluidiser () in one step only, whereby the height (h) of the step is at least equal to the average fibre length, and after the fluidiser () the biggest permissible step expression in the flow channel in direction z is smaller than the average fibre length.

Method for fluidisation of pulp flow in the headbox of a paper machine or such and control equipment used in the fluidisation

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

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Jyväskylä, Finland

Hannu Karema