Valmet Oy

Valmet Paper Machinery Inc.

Valmet Corporation

Vaino Sailas

Antti Kuhasalo

Antti I Ilmarinen

Heikki Ilvespaa

Pertti Heikkila

Bjarne Ekberg

Jouko Yli-Kauppila

Mikko Karvinen

Ilkka Jokioinen

Matti Korpela

Pekka Taskinen

Antti Lehtinen

Osmo Skytta

Markku Lampinen

Dick Parker

Henrik Petterson

A method and device for drying a paper web wherein the paper web is supported on a drying wire without long open draws of the web. The paper web is contact-dried by pressing it with the drying wire onto a face of a contact-drying cylinder whose diameter is greater than about 1.5 m on a sector b whose magnitude is greater than about 180.degree.. The web is evaporation-dried as blowing-on drying and/or as through-drying by means of high-velocity drying-gas jets applied to the web on the drying wire on the face of the following large-diameter cylinder whose diameter is greater than about 2 m on a sector a having a magnitude greater than about 180.degree. while the web is on the side of the outside curve. The web to be dried is passed over a sector c of the suction roll which is subjected to negative pressure while the web is supported on the drying wire at the side of the outside curve. The magnitude of the sector of the suction roll has a magnitude greater than about 160.degree. and the diameter of the suction roll is less than the diameter of the contact-drying cylinder.

Drying method and drying module as well as dryer sections that make use

A method for manufacturing a cylindrical mantle of rolls or cylinders of a paper machine out of a corrosion-proof metal or alloy material, particularly refined steel, in which oblong plate blanks are cut to a length equal to the total length of the roll mantle to be manufactured. The plate blanks are machined or bent to mantle portions of a cross-sectional shape equal to a part of a circular ring. Out of the mantle portions, the cylindrical mantle of a roll or cylinder is assembled by joining the mantle portions together by means of axial welding joints prepared by electron-beam welding performed in the vacuum chamber of an electron-beam apparatus by using a number of mantle portions per one roll mantle. A roll or cylinder manufactured by the method is also described.

Rolls and cylinders for use in paper machines

A method for the manufacture of the cylindrical mantle (10) of the rolls or cylinders of a paper machine out of a corrosion-proof metal or alloy material, particularly refined steel, comprises cutting oblong plate blanks (20A) of a length equal to the total length of the roll mantle to be manufactured. The plate blanks (20A ) are machined or bent to mantle portions (20) of a cross-sectional shape equal to a part of a circular ring. Out of the mantle portions (20), the cylindrical mantle of a roll or cylinder is assembled by joining the mantle portions (20) together by means of axial welding joints (14) prepared by electron-beam welding performed in the vacuum chamber of an electron-beam aparatus by using a number of mantle portions (20) per one roll mantle (10). A roll or cylinder manufactured by means of the method is also described.

Method for the manufacture of rolls or cylinders of a paper machine and

An apparatus, method and band for forming and/or dewatering a fibrous web, in which the web or a pulp suspension layer forming the same is conveyed and supported through a significant portion of its run in a paper machine by a specific processing band, while liquid such as water is simultaneously removed therefrom by hydraulically contacting the same with liquid present under vacuum or underpressure within the processing band, through a finely porous, liquid-suction surface on the band that is saturated with liquid.

Method and apparatus for dewatering a fibrous web

A press roll in a paper making machine comprises a non-perforated inner frame onto which an elastic layered structure is applied, the layered structure including an inner layer having a volume of which a substantial portion is constituted by cavities and an outer layer adapted to act against the inner surface of a looped press felt which passes through the press nip, the outer layer having passages formed therethrough which communicate with the cavities of the inner layer. During operation, the cavities are compressed together and thereby widen or extend the nip zone and, additionally, the cavities act as suction devices to produce a negative pressure in the nip zone following the centerline thereof. A press is disclosed which is formed by the press roll described above and a counter-roll which is provided with an elastic coating and a hollow face. A pair of press felts pass through the nip zone formed by these rolls between which the web to be dewatered is passed.

Press roll and press in a paper making machine

A method for manufacturing hard-surfaced cast iron articles, such as rolls for use in the steel industry or paper calendering rolls, includes the steps of casting the article in a manner such that upon cooling the crystal structure of the article is that of grey cast iron and remelting the surface to be treated by directing at least one electron beam onto a zone of the surface to be treated and cooling the remelting zones in a rapid manner so that a hard surface is obtained. The electron beam may be directed onto the zone of the surface to be treated in a punctiform and/or lineal manner, in one or a plurality of partial steps, and in a continuous or stepwise manner. The apparatus of the invention includes at least one electron gun, apparatus for mounting the electron gun and the article relative to each other such that the electron gun can direct an electron beam onto the zone of the surface to be treated to remelt the same and apparatus for displacing the electron gun and article relative to each other.

Hard-surfaced cast iron articles and method and apparatus for

A roll of the type which is used in paper machines has an inner roll body provided with an outer covering made up of a series of elongated strip portions which circumferentially surround the inner roll body while being distributed axially therealong and engaging each other. These strip portions are welded to each other and also may be welded to the inner roll body. The welding of the strip portions is carried out by way of an electron beam type of welding which can be oriented so as to achieve one or more of a number of different types of weld connections between the successive strip portions and, if desired between the strip portions and the inner roll body. Where the strip portions form part of an elongated strip which is helically wound onto the inner roll body, the welding by way of the electron beam can take place simultaneously with the winding of the strip onto the roll body, and by suitable controls the welding can be continuous welding or the welding may be applied at predetermined intervals to provide a discontinuous type of welding.

Roll and roll-manufacturing method

A strip-covered roll and the method for manufacturing the same, according to which the roll includes an inner roll body and a plurality of circumferential strip portions surrounding and engaging the inner roll body so as to cover the latter, these circumferential strip portions also engaging each other and being distributed axially along the inner roll body. Each circumferential strip portion has on one side a circumferential groove and on the other side an integral circumferential projection, and the projection of one circumferential strip portion is received in and fills the groove of the next circumferential strip portion, the groove having in its interior a greater transverse dimension than at the side surface of each circumferential strip portion which is formed with the groove, so that in this way the circumferential strip portions are locked to each other. According to the method, the circumferential projection of each circumferential strip portion is initially of a configuration enabling it to enter into the groove of the next circumferential strip portion, and when these strip portions are pressed against each other the circumferential projection is deformed so as to fill the groove and provide the interlock.

Method of making strip-covered roll

A roll manufacturing method and roll, particularly for paper machines, wherein an inner roll body is surrounded by a strip having circumferential portions such as windings which engage and extend outwardly from an exterior surface of the inner roll body with the successive windings or circumferential strip portions engaging each other so that the engaging side surfaces of successive strip turns define an interface between themselves. The side surfaces of the strip are formed with registering grooves which thus define a bore extending across the interface, and an elongated interlocking member is situated in the latter bore so as to interlock the successive turns or circumferential strip portions against radial displacement outwardly away from the inner roll body. The interlocking member preferably has a fluid-tight sealing engagement with the groove surfaces which define the bore which receives the interlocking member, so that the interlocking member also forms a moisture barrier.

Roll manufacturing method and roll, particularly for paper machines

A roll of the type which is used in a paper machine has an inner roll body covered with a plurality of strips. The strips include pairs of strip portions situated one next to the other along the roll body and covering the outer surface thereof. Each pair of strip portions extends through 360.degree. around the roll body with each pair of strip portions including one strip portion at least part of which circumferentially surrounds and overlaps at least part of the other of each pair of strip portions. This one of each pair of strip portions circumferentially presses radially inwardly against at least said part of the other of each pair of strip portions to press the other of each pair of strip portions against the outer surface of the roll body. The one of each pair of strip portions has a coefficient of thermal expansion greater than the other of each pair of strip portions and when initially placed on the roll body is in a heated condition at a temperature sufficiently high so that upon cooling the one of each pair of strip portions will contract against the other of each pair of strip portions to provide the circumferential inwardly directed radial pressure acting to press the other of each pair of strip portions against the outer surface of the inner roll body.

Growing community of inventors

Vaajakoski, Finland

Vaino Sailas