Voith Patent Gmbh

Voith Paper Patent Gmbh

Oliver Kaufmann

Volker Schmidt-Rohr

Thomas Ischdonat

Ingolf Cedra

Armin Bauer

Thomas Ruehl

Rudolf Münch

Thomas Rühl

Moritz Schmalenbach

Marco Esper

Peter Biener

Niels Hardt

Jens Haag

Rainer Wenzl

Pekka Typpö

A device for determining the weight per unit area of a moving material web, in particular a fibrous material web includes at least one microwave sensor that has an element for coupling the microwaves and a reference element. The coupling element and the reference element are located at a distance from one another in such a way that the material web can be moved therebetween. At least one microwave sensor element, the coupling element and/or the reference element can be moved such that the distances between the material web and the elements can be adjusted for or during the measurement of the moving material web.

Determination of basis weight of a material web using a microwave sensor, whereby the distance between the material web and the surfaces of the microwave sensor is being adjusted to a constant value by air cushions

The invention relates to a method for optimizing the energy balance of a forming section in a machine for producing fibrous webs, in which a fiber suspension, which is fed to the forming section by way of a material ramp after the immobility point is reached, is passed through at least two dewatering units within a compression zone and to a subsequent functional unit. The invention is characterized in that a setpoint value for a target dryness to be set is predefined based on the existing dewatering elements as a function of a theoretical maximum achievable dryness under plant conditions in the area of the transition zone, said setpoint being selected such that it is less than the theoretical maximum achievable dryness but is equal to or greater than a required minimum dryness in the area of the transition zone, and that the target dryness is controlled by lowering the inlet dryness at one of the last dewatering units disposed in the direction of passage of the fiber suspension within the compression zone.

Method for optimizing the energy balance in forming sections in machines for the production of fibrous webs, and forming section

A forming section in a machine for producing a web of fibrous material includes a control and/or regulating system including a control and/or regulating device which is connected with at least one device for at least indirect acquisition of one value at least indirectly characterizing the dry content of the fibrous web in a transfer area from the forming section to a following function unit, with a device for input of a desired value for the target dry content, and with at least the control elements of an individual dewatering unit located prior to one of the last dewatering units, or the last dewatering unit inside the compression zone. The control and/or regulating device also includes a device for creating the control variables for controlling the individual dewatering units.

Method for optimizing the energy balance in forming sections in machines for the production of fibrous webs, and forming section using control elements associated with dewatering units

In a method for determining the moisture of a running material web, in particular a paper web or paperboard web, the material web is scanned by way of a sensor including a microwave resonator, the resonance response of the microwave resonator is investigated, and the moisture in the material web is established in the light of this resonance response while taking account of the distance between the microwave resonator and the material web. Also disclosed is a corresponding apparatus for determining the moisture.

Method and apparatus for determining the moisture of a running material web

Sensor and process for measuring mass of water on a sheet forming fabric. The sensor includes a microwave element positionable to couple an electromagnetic field into a stock layer to be measured, and a microwave signal generator coupled to the microwave element to generate, in the microwave element, a microwave signal having a frequency lower than a relaxation frequency of water. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

Microwave water weight sensor and process

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Heidenheim, Germany

Oliver Kaufmann