Metso Paper Inc.

Valmet Technologies, Inc.

Valmet Aktiebolag

Rickard Andersson

Johan Bylander

Jörgen T Lundberg

Magnus Henriksson

Anders Bergdahl

Fredrik Pontén

Magnus Danielsson

Stefan Mattsson

Apparatus for washing and dewatering pulp and a system for controlling this apparatus are provided. The apparatus includes a pair of rotatable press rolls installed in vats and including a press nip therebetween, an inlet for feeding the pulp to the press nip, with one of the press rolls being movable in relation to the other and in which the processing of the pulp is determined by the number of variable operating parameters. The system includes apparatus for utilizing the distance between the press rolls as a variable operating parameter, for setting a desired value for a specific control parameter, for measuring the specific control parameter, and for adjusting at least two of the variable operating parameters during operation to maintain the difference between the desired value and the measured value of the specific control parameter below a predetermined difference.

System for washing and dewatering pulp

Methods for processing pulp in an apparatus for washing and dewatering pulp and a system for controlling this apparatus are provided. The apparatus includes a pair of rotatable press rolls installed in vats and including a press nip therebetween, an inlet for feeding the pulp to the press nip, with one of the press rolls being movable in relation to the other and in which the processing of the pulp is determined by the number of variable operating parameters. The method includes utilizing the distance between the press rolls as a variable operating parameter, setting a desired value for a specific control parameter, measuring the specific control parameter, and adjusting at least two of the variable operating parameters during operation to maintain the difference between the desired value and the measured value of the specific control parameter below a predetermined difference. Systems for controlling this apparatus are also disclosed.

Apparatus for washing and dewatering pulp, a system for controlling such an apparatus, and a method for processing pulp in such an apparatus

The present invention relates to a washing apparatus for washing of cellulose pulp comprising: a rotatable drum (), a stationary support (), a stationary cylindrical casing (), that encloses the drum, whereby an annular space () is defined between the casing and the drum, a number of seals () that are arranged on the casing and that seals between the casing and the drum, such that the annular space is divided in a formation zone (F), at least one washing zone (T, T), and a discharge zone (U), and at least a reinforcing frame rib (), that is attached to the casing. The reinforcing frame rib () extends around the entire casing () for fixing the casing in a predetermined form, whereby detrimental deformation of the casing (), when washing the paper pulp at overpressure, is prevented.

Arrangement for the treatment of cellulose pulp in a washing apparatus arranged with a reinforcing frame

Washing apparatus is disclosed comprising one or possibly two co-operating cylindrical press rolls, each having a perforated outer surface. A guide surface is provided at a distance from the perforated outer surface and encloses the respective press roll in the circumferential direction over at least 225&#xb0; of the roll's circumference, wherein a pulp passage is provided between the perforated outer surface and the guide surface. During operation, pulp that is fed into the pulp passage is guided in a direction of rotation of the respective press roll and is pressed in a pinch between the press rolls. The radial distance between the outer surface of the press roll and the guide surface is substantially the same throughout a portion of the pulp passage in the circumferential direction.

Arrangement for washing and dewatering cellulose pulp

A washer for washing and dewatering cellulose pulp is disclosed, comprising a rotary drum with a plurality of external compartments on the drum defined by axial compartment walls distributed along the circumference of the drum, a stationary cylindrical casing enclosing the drum, defining a ring-shaped space between the casing and the drum, and longitudinal seals in the axial direction of the drum diving the ring-shaped space into a forming zone for forming the pulp, at least one washing zone for washing the pulp at an overpressure, and a discharge zone, and where the longitudinal axial seals are attached to positioning cylinders for adjusting the radial position of the seals, and the longitudinal seal has an articulated connection with the positioning cylinders to make possible oblique positioning of the seal.

Arrangement for the treatment of cellulose pulp involving seal positioning means

A washer for washing and dewatering of cellulose pulp is disclosed, comprising a rotatable drum with a plurality of outer compartments for the pulp to be washed defined by axial compartment walls distributed along the circumference of the drum, a stationary cylindrical casing that encloses the drum, whereby an annular space is defined between the casing and the drum, the annular space divided by means of longitudinal seals in the axial direction of the drum into zones for forming, washing and discharge of the pulp. At least two of the longitudinal seals are arranged such that, when the drum rotates, they meet compartment walls at shifted points in time with respect to each other. Preferably, all of these longitudinal seals are arranged along the circumference of the drum at different positions with respect to respective opposite axial compartment walls.

Arrangement for treatment of cellulose pulp

Apparatus for washing and dewatering cellulose pulp is disclosed comprising: a rotatable press roll having a perforated outer surface for dewatering the pulp; a stationary guide surface arranged at a distance from the perforated outer surface so as to enclose the press roll in the circumferential direction, such that a substantially closed vat is defined between stationary guide surface and the press roll; a pulp passage, being provided between the perforated outer surface and its stationary guide surface, such that during operation, pulp is transported in the direction of rotation and, at the end of the pulp passage, is pressed in a pinch between the press roll and a second press roll. A radial distance between the stationary guide surface and the associated press roll is generally increasing towards the pinch, such that the vat diverges, towards the pinch.

A washer for washing and dewatering cellulosic pulp is disclosed, comprising a rotary drum with a plurality of external compartments defined by axial compartment walls distributed along the drum's circumference, a stationary cylindrical casing enclosing the drum, whereby a ring-shaped space is defined between the casing and the drum and where longitudinal seals divide the ring-shaped space into a forming zone for forming the pulp, at least one washing zone for washing the pulp at overpressure, and a discharge zone for feeding out the washed pulp, and the filtrates from different washing stages are collected in a peripheral valve located at the drum's end wall, the filtrate stages are separated by seals in the valve, and at least some of the valve seals are displaced in relation to the corresponding longitudinal seal, as seen in the direction of rotation of the drum.

Arrangement for the treatment of cellulose pulp in a washing apparatus arranged with displaced peripheral valve seals

A washing arrangement for washing and dewatering cellulose pulp is disclosed, comprising at least one rotary cylindrical element, against which the pulp is dewatered, and where a seal is located in an end seal holder, so that the seal has a contact surface against the rotary cylindrical element and an application surface placed against an applicator located in a groove in the end seal holder, where the seal has a longitudinal extension, which corresponds to either the entire or at least a greater part of the circumference of the cylindrical element, and is intended to seal against the end of the cylindrical element, and where the seal is a polymer ledge provided with an arming element.

Arrangement for the treatment of cellulose pulp

The present invention relates to a washing apparatus () for washing of cellulose pulp, comprising a rotatable drum (), a stationary support (), a discharge device () that has an outlet orifice (), a casing that surround the drum and that forms a longitudinal discharge opening () and a conveyer worm () arranged below the outlet orifice for reception and removal of washed pulp. The conveyer worm () is movably arranged relatively the support () between a first position (P), in which the conveyer worm receives washed pulp during operation, and a second position (P), in which the outlet orifice () is exposed and access to the drum () via the outlet orifice is possible for carrying out service, maintenance and inspection of the washing apparatus ().

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Matfors, Sweden

Rickard Andersson