Abstract: The multi-cylinder dryer of a papermachine comprises a first tier of cylinders, wherein a web travels supported by a first dryer wire on the cylinders of the first tier of cylinders, as well as a second tier of cylinders, wherein the web travels supported by a second dryer wire on the cylinders of the second tier of cylinders. Upon passing around its wire guide roll, each dryer wire forms a loop having at least one section, along which the first or second wire, respectively, is free from the web and which in this wire traveling direction is immediately upstream of a point, at which the first or second wire is received on the first or second guide roll.
Abstract: A dryer section of a paper machine including cylinder groups provided with single-wire draw having smooth-faced heated drying cylinders against which a web to be dried enters into direct contact, and reversing rolls. The groups with single-wire draw have a drying wire which is guided in a loop by guide rolls as well as by the drying cylinders and the reversing rolls so that the drying cylinders are placed outside the wire loop, and the reversing rolls are situated in gaps between the drying cylinders inside the drying-wire loop. In order to optimize the drying capacity calculated per unit of length of the dryer section in the machine direction, as the drying makes progress, a different ratio of the drying cylinder diameter to the reversing roll diameter is employed, so that, in the first group or groups in the initial end of the dryer section, the ratio is higher than the corresponding ratio in the groups in the middle area of the dryer section.
March 24, 1995
Date of Patent:
September 10, 1996
Ville Korhonen, Allan Liedes, Jouko Yli-Kauppila
Abstract: A group with single-wire draw in a dryer section of a paper machine having heated smooth-faced drying cylinders against whose smooth face a paper web to be dried is brought into direct contact, and reversing cylinders. The group with single-wire draw also includes a drying wire which is guided in a loop by guide rolls as well as by the drying cylinders and reversing cylinders so that the drying cylinders are placed outside the wire loop and the reversing cylinders are situated in gaps between the drying cylinders inside the loop of the drying wire. In the group with single-wire draw, the drying cylinders include large cylinders and small cylinders, the diameter of the large cylinders is substantially larger than the diameter of the small cylinders. The small cylinders are placed in gaps between the large cylinders so that their centers of rotation are on a level substantially different than the level of the centers of rotation of the large cylinders.
Abstract: The multi-cylinder dryer of a papermachine includes a first tier of cylinders, where the web supported by a first dryer wire travels on the cylinders of the first tier of cylinders, as well as a second tier of cylinders, where the web supported by a second dryer wire travels on the cylinders of the second tier of cylinders. The first dryer wire travels from a cylinder of the first tier of cylinders to a first guide roll and delivers the web lying on its side facing the cylinder of the first tier onto the second dryer wire and, after having wound onto a second wire guide roll, again takes up, on its surface facing the following cylinder of the first tier, the web from the second dryer wire traveling through the second tier of cylinders.
Abstract: A photosensitive material drying method for drying a photosensitive material conveyed along a conveying path, including steps of: training a front surface and a rear surface of the photosensitive material alternately around a plurality of heat rollers whose outer circumferences are heated by heat sources; heating the photosensitive material by an amount of heat provided on a basis of a temperature of the outer circumferences of the heat rollers and on the basis of a time of contact between the photosensitive material and the heat rollers; and evaporating moisture from a surface of the photosensitive material not contacting the heat rollers. High-quality drying can be effected in a small space and with little use of electric power. Efficient drying in which dimensions of films are stable can be carried out.
Abstract: A paper web impulse drying apparatus and method. A paper or paperboard web, typically of indefinite length, is treated after issuing from a Fourdrinier or other paper making apparatus by passing it through the nip of a pair of rolls, at least one of which is heated. The rolls both compress the web and raise it to a relatively high temperature. Such treatment enhances certain properties of the web. Web delamination due to flashing of superheated water, after the web leaves the nip, is prevented by both (a) a steam chamber on the exit side of the nip through which the web passes, and (b) heating the web prior to its entrance into the nip. This permits lower roll temperatures to be employed, thereby decreasing the magnitude of the sudden decrease in pressure experienced by the web as it exits from the roll nip. By preheating the sheet and passing it through the steam chamber, the temperature of the heated drying roll or rolls can be decreased to 120.degree.-150.degree. C.
April 27, 1993
Date of Patent:
April 11, 1995
International Paper Company
Vladislav A. Babinsky, Warren G. Mumford