Valmet Corporation

Metso Paper Inc.

Valmet Paper Machinery Inc.

Nokia Corporation

Metsuo Paper, Inc.

Petri Nyberg

Jyrki Huovila

Michael H Odell

Ari Linsuri

Juha Antero Kniivil&auml;

Jari Hamalainen

Kari Holopainen

Heikki Ilvespaa

John Shakespeare

Olavi Viitanen

Pekka Pakarinen

Kati Lindroos

Juhana Lumiala

Sakari Soini

Veli-Matti Rajala

Tapani Nyman

Petri Jetsu

Juha Salmela

Hannu Karema

Hannu Lepom&auml;ki

Markku Kellom&auml;ki

Antti Suoper&auml;

John Francis Shakespeare

Elina Pohjala

Jussi Ahola

Pentti Saarenrinne

The invention discloses a new and original voltage variable resistor VVR with input and output ports and a first input and second input for control signals to set the impedance between the input and output ports as desired over a certain range and, thus, to optimize the operation of the VVR from the transmitter device control viewpoint as regards both the linearity and minimum impedance. The invention further discloses a method for controlling a VVR and a cellular radio system terminal.

Voltage controlled resistor and a controlling method

The invention relates to a method of mixing pulp components in the manufacture of paper, in which method the pulp components to be mixed are led to a mixing point along tubes arranged inside each other. The pulp component flows are mixed by generating turbulence in them by means of the end of an inner tube, the cross-section of which end is wave-like. This turbulence is guided and its effect is intensified by means of form parts in connection with the mixing point, which form parts are arranged on the inner surface of the outer tube. Further, the invention relates to an arrangement implementing the mixing of pulp components in accordance with the method.

Method and arrangement for mixing pulp components in the manufacture of paper

An attenuator for radio frequency applications includes variable shunt elements and series transmission elements. The impedances of the variable shunt elements and the series transmission elements are selected so that the impedance of the attenuator at the input terminal remains at a nominal value for all attenuation levels, thereby producing low loss at high frequencies. The use of the attenuator as a switch yields a non-reflective switch at radio frequencies.

Circuit topology for attenuator and switch circuits

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

Method and apparatus for controlling the mixing proportions of feed streams being supplied to a headbox, using devices for sampling two or more of the feed streams upstream of the headbox and devices for measuring concentration of constituents in or other properties of those samples. A method of regulating one or more properties of a moving web, and especially a paper web during manufacture, employing the aforesaid method and apparatus are also disclosed.

Apparatus for controlling a headbox in a paper machine

The invention concerns a headbox for a paper/board machine by whose means the basis weight of the web can be regulated. The headbox comprises a stock inlet header (J ), which becomes narrower towards its end. Tubes ( , . . . ) in a tube bank ( ) open in the stock inlet header (J ) across the machine width, which tubes are connected with thickening elements ( , . . . ) across the machine width, in which connection a flow (L ) is removed from the thickening element into the duct (D ) and said flow (L ) to be removed is regulated by means of a valve (V , V . . . ). From the thickening element ( , . . . ) a tube ( , . . . ) for a flow (L ) of higher consistency is provided, which flow is passed further in the headbox.

Headbox of a paper/board machine by whose means the basis weight of the web can be regulated

Method and apparatus for controlling a headbox in a paper machine

A method for continuous overall regulation of a former of a paper or board machine or equivalent in which a physical fluid flow model of the drainage and the flow state of the pulp suspension flow is formed. The model is solved by making use of the data on the geometry of the former and initial and boundary conditions necessary for a solution to the model. The difference between the simulated state, which has been obtained as the solution of the physical flow model, and the state adopted as the target is determined as the cost function, wherein the target state is determined by means of the quality requirements of the paper and possibly by means of the costs of operation and the runnability of the paper machine. The cost function is optimized and, thus, optimal regulation values and set values are obtained for the regulation devices and/or actuators of the former in view of the given cost function. After the optimization has been carried out in the preceding stage, the former's regulation devices and/or actuators are given new optimal regulation and set values.

Method for overall regulation of a former of a paper machine or

A method for the continuous overall regulation of a single-layer or multi-layer headbox of a paper, board or pulp-draining machine. A physical fluid flow model of a pulp suspension flow discharged from the headbox to be regulated is formed and solved to obtain a simulated flow state based, e.g., on data on the geometry of the headbox and initial and boundary conditions related to the headbox. A target flow state based on the quality requirements of the paper produced from the pulp suspension flow and the costs of operation and runnability of the machine is obtained and a difference between the simulated flow state obtained as the solution of the flow model and the target flow state is determined. This difference constitutes a cost function which is optimized to determine optimal regulation values and set values for instrumentation devices and actuators of the headbox which affect the pulp suspension flow. The optimal regulation and set values are provided to the devices and actuators of the headbox such that the devices and actuators of the headbox may operate at the optimal regulation and set values.

Method for overall regulation of the headbox of a paper machine or

A method and device in the regulation of a headbox. The headbox includes a pulp inlet header, after the pulp inlet header, seen in the pulp flow direction, a distributor manifold whose pipes are opened into an intermediate chamber. The headbox comprises an attenuation chamber placed in connection with the intermediate chamber and, after the intermediate chamber, a turbulence generator having tubes which are opened, at their outlet end, into a discharge duct and, at their inlet end, into the intermediate chamber. In the method, into different positions along the width of the headbox, a pulp suspension flow is introduced, the concentration of this flow is adjustable by combining two component flows. In the method, in the regulation of the concentration of the flow passed into the pulp suspension, two component flows are combined by into the pulp suspension flow introducing an additional flow. The mixing ratio of the combined flow is regulated by adjusting the additional component flow. In the method, the additional component flow is passed into the pulp flow taken out of the inlet header.

Method and device in the regulation of a headbox

A method in the regulation of a pulp suspension flow through the headbox of a paper machine/board machine wherein an additional flow is introduced into the pulp suspension at different points across the width of the headbox. The concentration of the additional flow is regulated by a mixer unit which includes a displaceable distributor part such that when the mixing ratio is being regulated, the flow resistances of the component flows, of the additional flow, entering into the mixer unit are adjusted by displacing the distributor part of the mixer unit in a chamber of the mixer unit.

A multi-layer headbox including at least two inlet headers for stock through which separate stocks are passed into a system of distributor pipes and further through a turbulence generator into a slice cone narrowing in the stock flow direction. Flaps are placed in the slice cone and one end of the flaps is attached to the turbulence generator. The flaps have at least two flap faces between which a step is formed. The step is arranged on the flap in an area in which the flap, and the flow duct, is curved and its the function is to dissipate any secondary vortices that might form on the curved flap face.

Multi-layer headbox

A method and device for the regulation of a pulp suspension flow in a multi-layer headbox and a multi-layer headbox for a paper machine/board machine. For the formation of different layers in the web, at least two pulp suspensions having different pulp concepts flow through the multi-layer headbox. The flow of a pulp suspension that forms one of the layers in the web is regulated by regulating the component flows that constitute this flow and regulating the concentration of the component flows independently from one another. In this manner, i.e., by regulating only this the particular layer, the total flow of the pulp suspension leaving the headbox is regulated.

Method in the regulation of a multi-layer headbox and a multi-layer

The present invention relates to a method and device in the draw of a paper web for reduction and equalization of transverse shrinkage of the paper web in the drying section of a paper machine. The lateral areas of the wire running in conjunction with the paper web are provided with a coating adhesion means, whereby, by means of the coating adhesion means, at the drying stage an adhesion force is produced between the lateral areas of the wire and of the paper to prevent transverse shrinkage of the paper web.

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Jyvaskyla, Finland

Petri Nyberg