J. M. Voith Gmbh

Voith Sulzer Papiermaschinen Gmbh

Voith Gmbh

Wilfried Kraft

Wolfgang Mayer

Gerhard Kotitschke

Werner Kade

Hans-Peter Sollinger

Christian Schiel

Albrecht Meinecke

Andreas Meschenmoser

Hans K Dahl

Volker Schmidt-Rohr

Bernhard Kohl

Stefan Reich

Klaus Esslinger

Gunther Mohrhardt

Johann Preisetanz

Hans-J&uuml;rgen Wulz

Rudolf Bueck

Heinz Beck

Theo Hagele

Suction forming roll n double screen method and machine for the manufacture of a fibrous material web

A system for selective treatment of a traveling web, preferably of paper or cardboard, by surface treatment or impregnation in which at least one coater is in the case of web treatment arranged after a dryer group for treatment of the one side of web. At least one further coater for treatment of the other side of the web is arranged before a further dryer group. Noncontact web deflectors are arranged after the coaters and noncontact dryers can be installed retroactively in existing dryer sections.

System for selective treatment of a traveling paper web

The dry end of a paper machine comprises a first dryer group with top drying cylinders, with a first drying wire and with bottom deflection suction rolls. Adjacent this, there is a second dryer group with bottom drying cylinders, with a second drying screen and with top deflection suction rolls. In this way, both sides of the web to be dried come, in succession, into direct contact with the drying cylinders. At the place where the web changes from the first drying wire to the second drying wire, there is a transfer suction roll which lies within the loop of the second support belt. The web travels there from the last cylinder of the first dryer group over an at least approximately straight travel path to the transfer suction roll and thus onto the second support belt.

Dry end with open reversal place

The present invention relates to a dryer section of a machine for the production of fibrous web, such as a paper web. The dryer section comprises at least one dryer group having at least one drying cylinder and an endless porous support belt that guides the web around each cylinder. This is followed by a reversing roll being formed as a suction roll. With the web being supported by said porous support belt the web directly contacts said reversing roll. A distance of at least 150 mm is provided between the cylinder and the reversing roll. A sealing strip extends transversely over and close to the inner side of the endless porous belt in the region where web and belt are traveling off the cylinder. For deflecting the air boundary layer which arrives together with the belt, a sealing support beam also extends transversely over the inner side of the belt and supports the sealing strip. The beam, the sealing strip, the reversing roll and a section of the belt which is tangential to the cylinder and the reversing roll together define an area of negative pressure.

Dryer section

A twin-wire former for a paper machine having two endless loop wires, a wire support frame and a head box. The web forming zone leading from the entrance slot, which is at the breast roll in one wire loop and the forming roll in the other wire loop, is inclined at an angle of 30.degree. to 50.degree. to the horizontal. The wire support frame has the shape of an inverted U with a front support arranged upstream of the head box, a rear support arranged downstream of the headbox and an upper beam which connects the upper ends of the front and rear supports to each other. A lower beam is located within the loop of the lower wire and extends to both of the forward and rearward sides of the rear support with one end extending into the U-shaped frame while the other end extends at least approximately up to the remote end of the loop of the lower wire. At least one water removal element of the upper wire is suspended from the upper beam. At least one water removal element of the lower wire rests on the lower beam.

Twin wire former for a paper making machine

The dry end of a paper machine comprises a first dryer group with top drying cylinders (11 to 14), with a first drying wire (10) and with bottom deflection suction rolls (21 to 23). Adjacent this, there is a second dryer group with bottom drying cylinders (15 to 18), with a second drying screen (20) and with top deflection suction rolls (25 to 27). In this way, both sides of the web (9) to be dried come, in succession, into direct contact with the drying cylinders. At the place where the web (9) changes from the first drying wire to the second drying wire, there is a transfer suction roll (24) which lies within the loop (20) of the second support belt. The web (9) travels there from the last cylinder (14) of the first dryer group over an at least approximately straight travel path to the transfer suction roll (24) and thus onto the second support belt (20).

Dry end

A paper making machine comprises a press followed by an adjoining dry end having a plurality of dryer groups I to VI. Each dryer group comprises only one row of dryer cylinders and one row of reversal suction rolls which alternate with the dryer cylinders, and a respective endless support belt passing around the cylinders and rolls of each group along a guided meander path. The press and each of the dryer groups has a respective variable web speed drive. A speed control device controls the drives such that a positive difference in speed is present between the first dryer group and the press and a negative difference in speed is present between the last two dryer groups. Separation places may be defined between at least some of the dryer groups. Some of the separation places are closed providing support for the web passing between groups, and others are open providing an unsupported open draw for the web.

Dry end of a machine for the production of a fiber web

A dry end of a paper making machine has a plurality of dryer groups each in turn comprised of a plurality of heatable dryer cylinders which alternate with reversal rolls. A respective support belt meanders past each dryer cylinder and the succeeding reversal roll in each dryer group. The web to be dried is supported on the side of each support belt to contact the heatable dryer cylinders. The reversal roll that precedes the first dryer cylinder in each succeeding group serves as a web removal roll which is wrapped by the second support belt of the succeeding dryer group. The first support belt of the preceding dryer group has the web on the side of the first belt which is toward the removal roll. The first support belt contacts the second support belt on the removal roll over a smaller part of the circumference of the removal roll than the second support belt. The removal roll transfers the web from the first support belt to the second support belt at the removal roll. There is an unsupported length of the first support belt from the last reversal roll of the first dryer group to the removal roll in the second dryer group that is of a length that the time of travel of a point on the first support belt between those two rolls is at least 0.05 seconds and preferably between 0.06 and 0.12 seconds. That zone is free of suction devices. The first support belt and possibly the second or preferably porous dryer wires. A boundary air layer deflection device opposite the removal roll deflects the boundary layer of air through the first support belt to help deflect the web off the first support belt onto the second support belt at the removal roll.

Dryer group web transfer region for paper making machine

Twin-wire former with frame for a paper making machine

In a web pick-up device and a method of using the pick-up device in the press section of a paper machine, the running web makes contact, in a press gap, with a smooth rotating surface from which the web runs off at a point of pickup (A). The rotating surface and a suction box form together, in the area of the pickup point (A), a gap through which runs a porous conveyer belt which receives the fibrous web. The suction box is pivotably mounted and has in the area of the point of pickup (A) a sliding surface across which slides the conveyer belt, and which during operation is arranged at an adjustable spacing from the smooth surface. The spacing is determined by a stop on which bears the suction box during operation, under the effect of a flexible lift device.

Web pick-up device and method for transfer of a paper web

A dry end of a paper making machine comprising two dryer groups of dryer cylinders each followed by a respective web path reversal roll, which may be in the form of a suction guide roll, and a respective porous web support belt that meanders past each dryer cylinder and the next web path reversal roll for each dryer group. The last one of the first dryer group reversal rolls and the first one of the second dryer group reversal rolls, and additional guide rolls for guiding both the first and the second support belts, being so placed that at the place where the web is transferred from the first support belt to the second support belt, there is a spaced distance between the first and the second support belts. A web separation device generally inside the loop of the first support belt and opposite the first one of the second reversal rolls directs air through the first support belt to help transfer the web from the first support belt to the second support belt at the first one of the second reversal rolls. The web transfer device may be an additional blast zone on the circumference of the last one of the first reversal rolls, or an additional guide roll for the first support belt positioned to deflect the air, or another deflecting device positioned to deflect the air.

Dryer group web transfer region for paper making machine with open draw

A dryer section of a paper making machine is divided into several dryer groups, each comprising a plurality of dryer cylinders, a plurality of reversing rolls between neighboring cylinders and a respective web supporting belt wrapping around the cylinders of a dryer group. Within each dryer group, the web travels, in continuous contact with the supporting belt, alternately over the dryer cylinders and the reversing rolls so that the web comes into direct contact with the cylinders and the supporting belt comes into direct contact with the reversing rolls. The cylinders are arranged in several rows which are inclined to the vertical, alternately rearwardly and forwardly defining V-shaped double rows. The end of each row and the starting point of the following row are formed by two cylinders arranged horizontally alongside of each other. The rows of dryer cylinders succeed each other in the manner of a zig-zag line. Each inclined row comprises about three cylinders.

Dryer section with inclined rows of dryers

Twin-wire former

A paper-making machine has a plurality of drying cylinders for removing moisture from a wet web. The drying cylinders are arranged so that some of them are located in an upper plane and are hollow and have their interior connected to a source of suction, and others are located in a lower plane and are heated to form contact heaters. An endless traveling carrier band is trained about these cylinders in such a manner that its one surface which carries the wet web faces away from the hollow cylinders as it travels about them and faces towards the heated cylinders as it travels about the latter.

Growing community of inventors

Heidenheim, Germany

Wilfried Kraft