Abstract: A web dryer structure for thermal removal of liquid from a traveling web such as a web of paper coming from the press section of a papermaking machine including a row of upper dryer drums and a row of lower dryer drums with the drums positioned to carry the web in a sinuous path successively between upper and lower drums and the web wrapping the upper and lower surfaces of the drums respectively with upper and lower looped felts wrapping the web on the upper and lower surfaces of the drums with the felt guided by felt rolls which for the upper felt is beneath lower drums and for the lower felts are between the upper drums with the felt rolls being hollow roll shells and having glands therein divided so that a first portion of the felt roll faces the onrunning web and a second portion faces the offrunning web with the vacuum means and pressure means connected to the interior of the felt rolls so that one portion is subjected to a vacuum, and the other portion is subjected to a pressure, and the arrangement acc

Abstract: An air guide box for the dryer section of a paper making machine is arranged as generally between two succeeding drying cylinders and along a continuous support band or belt which supports the associated paper web to be dried; the air guide box has an end of generally wedge-like configuration which extends at least some distance into the gore-like space as exists in the region where the support band or belt runs onto the next drying cylinder; a first gap exists generally between a first wall of the guide box and the running support band or belt while a second gap exists as between a second wall of the guide box and the juxtaposed surface of such next drying cylinder.

Abstract: A method of drying a veneer sheet is provided. The method comprises the steps of tenderizing, compressing, and drying a veneer sheet. The compressing and drying steps are performed at the same time. The tenderizing step is preferably be performed before the above two steps but may be done thereafter or at the same time. An apparatus for performing the method is also disclosed. The apparatus comprises tenderizing means, deceleration transfer means, and heating means. The deceleration and the heating means are combined into one section. A plurality of rollers are used as deceleration transfer means.

Abstract: A paper machine multiple cylinder dryer includes a plurality of drying cylinders, in conjunction with which a drying fabric supports the web as it moves from one cylinder to another in closed conduction. A supporting fabric supports the web on some of the cylinders. The runs of the web supported by the drying fabric, the free surfaces of the drying cylinders and the runs of the supporting fabric confine elongated pockets in conjunction with the cylinders. In order to prevent web breaks occurring in the drying section of the fast-running paper machine, since such breaks are among the most important factors limiting the increasing of paper machine speeds, the multiple cylinder dryer provides a pressure greater than the ambient atmosphere pressure in the pockets in the direction of travel of the web, at least in the initial part of the dryer. This results in the considerable stabilization of the running of the web.

Abstract: A cylinder dryer usually includes a plurality of heated cylinders (4) about which a web-like material (1) is taken in a zig-zag mode and pressed against certain of the heated cylinder surfaces by means of an endless high-permeability wire (3), whereby cylinder pockets are formed between the cylinders (4), web (1) and wire (3), when the latter relinquishes contact with the web at a cylinder surface (6) to pass over a return roll (7) arranged between the cylinders, and once again makes contact with the web at the next following cylinder circumference (8). According to the invention these cylinder pockets are ventilated by a flow of drying air from a blowing box (9) being blown over the width of the wire against its surface facing away from the cylinder, in a direction forming an acute angle to and having a directing component substantially counter to the direction of travel of the wire. Blowing is carried out thereby within an area (6) where the wire relinquishes contact with the web.

Abstract: The invention relates to an arrangement for pulling the tail of a web-like material through a drying or cooling plant. In such a plant the web-like material is floated on air at a given distance from a surface provided with air delivery orifices. The web-like material (10) is thereby caused to pass zig-zag over drivable reversing rolls (2), while an endless traction or pulling member (3) in the form of a belt or rope runs in a separate path through the plant, substantially parallel to the material web, and is provided with means (12,13,14,15) with the aid of which the forward web end or tail (11) is attachable for pulling through the plant. At least one of the reversing rolls (2) is adapted at one end portion for carrying the tail pulling member either directly or over a pulley (9) drivably connected to said end portion. Driving the tail traction member is performed with the same means as drive the reversing rolls.

Abstract: An air-directing device for directing air to the multiple cylinder dryer of a paper machine includes members for blowing dry air into the vicinity of the web at those points where the evaporation of water from the web is strongest. This reduces the humidity in such regions and promotes the evaporation of water from the web. The points are the initial parts of the cylinder intervals after contact with the web. The air-directing device is so placed, and its air-blowing members are so disposed and directed, that the air blown out from such members is directed into the clefts defined by the surface of the drying cylinder and the paper web. This achieves a pressure effect in the clefts. The air-blowing members are primarily used in connection with single fabric conduction in pockets on the side of the web to urge the web fast to the fabric and are preferably disposed on a doctor beam or in conjunction therewith.

Abstract: A method and mechanism for dewatering a web in a paper making machine having press means, a first thermal dryer section having a long continuous support looped belt carrying the web along a first drying run with rolls and suction zones beneath the web and a hot air generating means for directing a flow of air onto the web in the first thermal run with the web being received substantially 40% bone dry at the beginning of the first thermal run and being delivered substantially 50% bone dry at the end of the run onto a heated drum dryer section.

Abstract: An improved vacuum box is described for holding a paper web onto a supporting fabric wherever velocity stresses would otherwise separate the web from its supporting fabric and expose the web to those stresses. Specially shaped vacuum boxes are fitted into the dryer "pockets" formed between the rows of a double row of adjacent drying cylinders and the web traveling a serpentine path between them. Pressure differential zones of the box hold the web onto its supporting fabric as the web and fabric travel between heated drying cylinders. A first zone leads the departure of the web and fabric from the web-wrapped cylinder to ensure that the web is positively held to the fabric as it leaves the cylinder. A second arcuate suction zone adjacent a fabric-wrapped cylinder evacuates grooves in the adjacent cylinder.

Abstract: In an apparatus for treating a layer of material, particularly in a number of successive thermal treatment phases with different treatment temperatures and durations, for carrying out at least two successive treatment phases, there is provided a roller with a roller shell, on to the outer wall of which the layer of material is applied, and which is rotatably mounted about a stationary carrier. Mounted on the carrier are a number of heat-conducting lines at least equal to the number of treatment phases to be carried out. The lines extend parallel to the roller shell and are mounted behind one another in the direction of rotation of the roller shell. They comprise elements which are connected to feed ducts for tempered media and each carry a tempered or cooled medium towards the inner wall of the roller shell.

Abstract: Methods and apparatus for drying a web of material running between a drying cylinder and a traveling covering cloth avoid the formation of air boundary layers which would impede heat exchange with respect to, and humidity removal from, the traveling web. In particular, these methods and apparatus avoid excessive wear of the covering cloth by locating a baffleplate at a distance from the covering cloth within a domain of the boundary layer, and promote a heat exchange and humidity removal through turbulence by impacting air from the boundary layer against a front surface of the baffleplate at a distance from the covering cloth, causing an exchange of air in the boundary layer and in meshes of the covering cloth. Effects of non-uniform humidity profiles are avoided by providing the front surface of the baffleplate with a varying configuration across the covering cloth.

Abstract: A method and apparatus provided at the initial stages of the drying section in a paper making machine for reliably transporting the web from the press section to the drying section and for reliably transporting the web at the initial drying section stage including a group of drying cylinders including a pair of substantially horizontal rows of drying cylinders located one above the other defining an upper drying cylinder row and a lower drying cylinder row and a web supporting lower endless drying belt extending alternately between drying cylinders in said upper and lower drying cylinder rows alternately lapping sectors of the drying cylinders in the upper and lower rows. In its transport over these drying cylinders the web is separated from the drying cylinders in the upper cylinder row by the lower drying belt while the web is in contact with the drying cylinders in the lower cylinder row.

Abstract: A drying apparatus for wet paper webs which employs a rotary drum having a foraminous cylindrical wall and being located between but spaced apart from two parallel drying rolls with foraminous or impermeable cylindrical walls. The major part of the drum is surrounded by a hotair hood, and an endless wire screen is trained over the rolls as well as over that part of the drum which is surrounded by the hood. The screen forms a loop which surrounds a stationary suction chamber extending into the space between the rolls and having an open side facing the drum as well as the spaces between the drum and the rolls. The suction chamber has one or more sealing strips which are closely adjacent to the screen upstream of the first roll (as considered in the direction of transport of a web) and downstream of the second roll. The leader of the web is threaded between the screen and the first roll, thereupon around the drum between the screen and the hood, and finally between the screen and the second roll.

Abstract: A mechanism for controlling the loose trailing end of a strip of paper passing through a photographic dryer and includes soft, readily yieldable retarding elements mounted in inclined relation to the downward run of the path of the paper strip through the dryer in generally opposed relation to the discharge of hot drying air from a pressurized distribution plenum. In paper processors individual strips of photographic prints are transported therethrough by being attached at their leading ends to a transport belt which carries the strips through a tortuous path including a downward run with the hot drying air being blown against the surface of the paper to be dried. Since only the leading end of the photographic paper is attached to the transport belt, the trailing end is loose and tends to fall down within the downward run portion of the drying chamber.

Abstract: 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.