Abstract: A blow box (40) is disclosed which is disposed within a pocket (26) defined by a web (W) and felt (F) travelling together from a first dryer (12) to and around a second dryer (14) and onto and around a third dryer (16). The blow box (40) includes a wedge-shaped box extending from between the first and third dryers (12 and 16) to adjacent the second dryer (14), the box (40) being connected to a source of pressurized air (42) for maintaining the web (W) in close conformity with the felt (F) when the web and felt diverge relative to the first dryer (12). The box (40) defines an orifice (44) which is disposed adjacent to the first dryer (12) for directing pressurized air against the felt and then redirecting the air in a direction opposite to the direction of rotation of the first dryer (12) such that the web is urged against the felt for inhibiting the tendency of the web to adhere to the first dryer (12) when the felt diverges relative to the first dryer (12).

Abstract: An assembly for use at the nip between a dryer fabric and a dryer bottom roll at a location at which the fabric moves onto the roll and at which the web to be dried is outside the fabric. A shroud having first and second walls which diverge from a nose is assembled with a plenum chamber body having downwardly converging walls with an opening between the lower ends. The upper edge of one wall of the shroud is secured to one wall of the body to form a first plurality of orifices with the nose of the shroud below the opening and with the other wall of the shroud extending upwardly along and in spaced relation to the other wall of the body. One edge of a baffle extending across the body opening is secured to the one wall of the shroud with the other edge of the baffle connected to the other body wall at a location below the upper end of the other shroud wall to form a second line of orifices.

Abstract: A control valve (22) is disclosed for controlled both the flow of steam (S) from a steam header (18) and air (A) into a steam box (12) of a web drying machine. The control valve (22) includes a valve body (26) defining a longitudinal passageway (28). The passageway (28) has a first and a second end (30,32) with the first end (30) of the passageway (28) being connected to, and in fluid communication with, the steam header (18). The second end (32) is connected to and in fluid communication with an air header (19). A first and a second valve seat (34,36) are disposed adjacent to the first and the second ends (30,32) of the passageway (28) for controlling respectively the flow of steam (S) and air (A) into the steam box (12). An elongate valve stem (38) having a first and a second valve closure (44,46) is movable axially within and along the passageway (28), the first and second closures (44,46) being disposed adjacent to a first and second end (40,42) of the valve stem (38).

Abstract: A drying apparatus for sheets of sliced veneer has two conveyor belts lying one above the other running together jointly around a partially curvilinear, looped path guided by a plurality of guide apparatuses, the belts being positioned so that the sheets may be inserted between the belts for transport in a direction transverse to their widths, wherein the conveyor belts run rectilinearly between at least two of the adjacent guide apparatuses for a distance at least equal to half the maximum width of the sheets fed between the belts. The guide apparatuses may be rotatable cylindrical structures, for example rollers or cylinders, whose axes of rotation preferably all lie in the same horizontal plane. These rotatable cylindrical structures may be provided with brakes, drying and heating units as well. Furthermore the drying apparatus provides a velocity difference between the belts of from 2% to 5% and the belts passing between adjacent pairs of rollers are inclined at angles from 30.degree. to 75.degree..

Abstract: The invention concerns cooling apparatus for strip metal of the kind comprising a series of spaced cooling rolls around which the strip metal is passed such that it follows a serpentine path and is cooled by contact with the rolls, and elongate gas jet devices disposed widthwise of the strip opposite the outer surface parts of respective cooling rolls in contact with the strip.

Abstract: The invention relates to an arrangement in cylinder drying, intended for incorporation in a paper machine and including a plurality of heated cylinders (1) arranged substantially parallel in two rows, about which the paper web (2) is taken serpentine during drying, whereat it is carried by an endless porous fourdrinier wire (3) which presses the web against the cylinder surfaces in one row of cylinders and lies between the paper web and the cylinders in the other row. For preventing the web from lifting from the wire as a result of pressure differences on either side thereof, there are blowing boxes (11,12) arranged for blowing out air in at least some of the pockets (4,5) situated on opposite sides of the web, each of said pockets being formed by the web and three cylinders lying consecutively in the travelling direction of the web.

Abstract: A waste heat boiler is used to provide hot air to the drying hood of a Yankee dryer and to provide steam to the inside of the Yankee drying cylinder.

Abstract: In a method of and apparatus for heat-drying of webs, especially printed or inked webs, the web is first subjected to a contactless heat shock treatment, for example by hot air at about 300.degree. C. It is then heated by a contact process at a lower temperature, for example by heated rollers at about 230.degree. C., after which it is cooled by a contact process in a third step. Each of the heated rollers may have associated therewith a roller for applying a film of a buffer agent and also a cleaning roller. Energy expended in the processes is recovered by the use of heat exchangers. The apparatus may comprise a closed housing divided into separate chambers within which the sequence of steps is carried out.

Abstract: In a paper making machine, transfer apparatus for guiding a paper web from the press section to the drying section includes a smoothing press including upper and lower smoothing press rolls wherein the web is passed from the press section to the smoothing nip either directly or guided by a guide roll. The lower smoothing press roll of the smoothing press is substantially situated at a position which is normally occupied by a so-called baby or lead-in cylinder of a conventional drying section and the drying wire of the drying section is guided over a sector of the lower smoothing roll which is of a size sufficiently large that the web is transferred onto the drying wire which then carries the web as a closed draw onto the first drying cylinder of the drying section and, preferably, to the subsequent drying cylinders as a so-called single-fabric draw.

Abstract: The invention relates to a sealing device in a cylinder drier, intended for incorporation in a paper machine and including a plurality of cylinders arranged in two substantially parallel rows (1a,1b), the paper web (2) being trained serpentine about said cylinder during drying, said web being carried by an endless porous Fourdrinier drier (3) adapted for pressing the web against the cylinder surfaces in one row of cylinders and situated between the paper web and the cylinder surfaces in the other row. Two shielding members (7,15) being disposed in the space restricted by the wire and an intermediate cylinder surface on that cylinder which the wire and the web come onto and leave. Said shielding members facing the wire and extending substantially in parallel with and close to the wire and over the entire width of the web.

Abstract: Apparatus and method for guiding a fibrous web from a press section to a drying section, such as guiding a paper web from the press section to the drying section in a paper-making machine. The apparatus comprises a fetching roll adapted to guide the web passing from the press section onto a drying wire from the drying section passing about the fetching roll, and means for urging the web and drying wire against one another as the web is passed to the drying section, this urging means disposed between the fetching roll and the drying section in a running direction of the web and wire. The method of the present invention comprises passing the web from the press section onto a drying wire passing about a fetching roll, and urging the web and drying wire against each other as the drying wire passes from the fetching roll to the drying section.

Abstract: Apparatus for ventilating pockets in a multi-cylinder dryer of a paper machine of the type in which guide rolls are situated in spaces between adjoining drying cylinders and wherein a wire or felt has free runs between the drying cylinders and the guide rolls. With respect to a particular pocket to be ventilated, the apparatus functions to blow air through the inlet or incoming free run of the wire into the pocket with air being removed from the pocket at least partially through the following or outgoing free wire run following the guide roll. The apparatus comprises nozzle apparatus including a nozzle nose situated proximate to the incoming free wire run, at least two nozzles being defined by the nozzle nose which extend transversely to the direction of run of the wire. Air is blown through the nozzles into a space defined by the incoming free wire run facing the nozzles, by the guide roll and by the nozzle nose.

Abstract: The surfaces of cylinders or fabrics moving in the press or drying section of a paper machine induce layers of air along with them, which layers of air produce positive and negative pressures at the pits or nips defined by the fabrics or web and the surface of the cylinder. The positive and negative pressures are detrimental to the mutual support contact between the web and the fabric. A method for eliminating the detrimental positive and negative pressures affects the pressure levels at the nips by blowing air in directions opposite to the direction of travel of the web or fabric passing close to a blowing device, and possibly also opposite to the direction of travel of the cylinder surface. As a result of the blowing of air, air is ejected from the pressurized nips or from spaces placed facing the nips of negative pressure on the opposite side of the running of the web and the fabric. Apparatus for carrying out the method includes a blow box placed in connection with the nip.

Abstract: Cylinder dryer for a paper machine comprising a plurality of drying cylinders (10,20). The paper web and its lead strip are conducted between said cylinders (10,20) supported by a fabric (11). For guiding through the cylinder dryer the lead strip (L) having a width of a smaller order of magnitude than the normal width of the web (W), an air blowing means has been arranged adjacent to the drying cylinder and the free draws thereinbetween. Said air blowing means urges the web lead strip against the surface of the supporting fabric (11) or the cylinder. Said blowing means has substantially the same width as the lead strip and it carries a plurality of nozzles holes (14), through which air jets (F.sub.1,F.sub.2) are directed against the web. The covering angle of said air blowing means substantially equals that angle (.beta.) on which the web supporting fabric (11) and the web (W) on its outside change direction.

Abstract: In equipment for drying lengths of materials, in particular lengths of paper, with the length being guided by means of a permeable belt in a semi-circle around a drying drum and being deflected by a guide roller toward a next drying drum which is enveloped in the same manner, with blow boxes being arranged between the drums to supply the drying medium, the improvement comprising means mounting blow-out sections (7) of the blow boxes (3) in a displaceable manner in the radial direction of the drying drums (1, 2) within a frame (12), and means whereby the sections can be returned into their initial positions.

Abstract: In the dryer section of a paper making machine, the paper web is pressed against the drying cylinders by means of an air-permeable endless support band. An air blast apparatus extends transversely of the paper making machine and creates an air flow which is directed generally across and through the support band and onto the paper web. The air blast apparatus has at least one blow orifice in the form of a ring slot with two longitudinal slots extending generally longitudinally of the air blast box or housing of the air blast apparatus, and at least generally transversely of the paper web and the support band. The blowing directions of the two longitudinal slots may be at different angles with respect to the running direction of the support band.

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 pocket ventilation roll baffle assembly adapted for use in drying a paper web is disclosed. The pocket ventilation roll includes a stationary tubular inner core roll, a tubular outer shell roll mounted for rotation in concentrically spaced relation about the inner core roll, and a device for supplying drying air within the inner core roll. The drying air flows longitudinally through the inner core roll and radially outwardly through an arcuate portion of longitudinally arranged perforations contained in the inner core roll and circumferential perforations contained in the outer shell roll. The pocket ventilation roll baffle assembly includes a baffle arrangement for adjusting the profile of the drying air flowing radially outwardly from the pocket ventilation roll.

Abstract: A web dryer structure for thermal removal of moisture 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 guide rolls which for the upper felt are beneath upper drums and for the lower felts are above lower drums with the guide rolls being hollow roll shells and having glands therein divided so that a first portion of the guide roll faces the onrunning web and a second portion faces the offrunning web with vacuum means and pressure means connected to the interior of the guide rolls so that one portion is subjected to a vacuum, and the other portion is subjected to a pressure, and the arrangement accomm

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 a simple mechanical system to effect removal, reduction or change in composition of boundary layered atmosphere associated with web passage around a heat transfer roll. In effect, the purpose of the invention is to eliminate the layer of air between the web and the heat transfer roll, or to eliminate as much air as possible so that better and more intimate contact is achieved between the web and the heat transfer roll, or to change the pressure and composition of the atmosphere, thus assuring higher efficiency of heat transfer from the roll to the web. The mechanical structure can involve a squeeze roll positioned between the heat transfer roll, squeezing the boundary layer of air attached to the web out prior to web contact to the heat transfer roll. In addition, the squeeze roll could utilize some type of vacuum associated with it.

Abstract: A web that is coated or imprinted on both surfaces has a straight stretch that emerges from a dryer enclosure in which the web is heated and extends to a chill roll around which a curved portion of the web is partially wrapped. A duct-like tunnel surrounding said stretch has its outer end near the chill roll. In a preferred embodiment, a nozzle at the outer end of the upper tunnel wall blows a blade-like jet against the curved portion of the web to force it into intimate engagement with the chill roll periphery and thus prevent accumulations of solvent vapor condensate thereon. Part of the jet air deflected by the web is guided inwardly along the web by the upper tunnel wall. Air outlets just above the lower tunnel wall, near its outer end and spaced at intervals across it, provide for inward air flow under the web. Practically all vapor emanating from the web after it leaves the dryer is thus driven into the dryer.

Abstract: A paper web drying apparatus having a throughdrying drum wherein heated air is supplied beneath a hood around a portion of the periphery of the drum through which the air may pass, the hollow interior of the drum being connected to exhaust means, the hood distributing heated air to the surface of the web, the improvement according to the invention comprises dividing the hood into at least two separate sections, the section adjacent the web inlet having a series of nozzles connected to a source of heated air and interspersed air ducts or the like connected to air exhaust means, the section adjacent the web outlet being connected to a source of heated air but not to exhaust means. This enables impingement drying to take place adjacent the web inlet, impingement and throughdrying to take place at a point further along the arc of travel of the web beneath the web and only throughdrying to take place during the final portion of the web travel.

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: 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: An improved paper drying process and machine are described in which the paper web is supported independently of velocity-induced stresses thus permitting operation at speeds significantly in excess of the prior art for each paper grade. The process requires: (1) transporting the web on a supporting fabric that travels from the last press nip through at least the initial portion of a drying section; and (2) holding the web onto its supporting fabric by employing forces normal to the major web surfaces sufficient to overcome those forces which tend to lift the web from its supporting fabric. The web on its supporting fabric travels a serpentine path through the drying section about drying cylinders with the web alternating between direct contact with a drying cylinder followed by indirect contact with the subsequent cylinder.

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: A hood for the cylinder drying section of paper making machines and other cylinder drying machines comprising a framework composed of hollow square or rectangular tubes supporting the hood through which heated air is passed for delivery between the cylinders, inlet air being drawn in by a fan and passing over a heat transfer unit and a steam battery separated from the cylinder chamber by an inclined diaphragm wall and an exhaust fan for drawing the moist air from the cylinder chamber through a damper valve controlled duct to the heater chamber for recirculation or exhaust.

Abstract: A freshly printed continuously traveling paper web leaves a heated print drying zone hot with its printing dry enough to avoid smudging but retaining a residual amount of the printing ink's solvent oil which continues to vaporize, forming a boundary layer of vaporizing oil traveling with the web. For cooling, the web wraps partially around one or more cooling rolls where condensation can cause the vapor boundary layer to condense on the exposed cold roll surface to a liquid phase, exerting a solvent action more or less resoftening the otherwise adequately dried printing with consequent smudging on the roll surface. To prevent this, the boundary layer is pneumatically removed from either this exposed surface of the roll not contacted by the web, or from the web itself, preventing resoftening of the printing by what would otherwise be liquid solvent oil.

Abstract: A paper machine drying section and method for operating the same are provided for reliably maintaining a web in engagement with a drying fabric at locations where the fabric is situated between the web and drying cylinders. Those drying cylinders which are directly contacted by the drying fabric, so that the web is separated therefrom by the drying fabric, are formed with recessed outer surfaces having voids across which the fabric extends. The pressure in these voids is maintained at a magnitude less than the pressure at the outer surface of the web where it travels around those cylinders from which it is separated by the fabric, so that in this way the web is urged by the pressure differential toward the fabric so as to be incapable of becoming detached therefrom.

Abstract: The web drying section of a paper machine has a plurality of drying cylinders; an air permeable belt passes around one cylinder and the web to be dried passes outside the belt around the one cylinder; gussets defined in the region of initial engagement and final disengagement of the feeder belt with the one cylinder; the entrance side gusset includes an air lock to eliminate the boundary layers of air on the feeder belt and the drying cylinder and to minimize return of ambient air into the entrance side gusset, thereby to hold the web to the belt and drying cylinder; the exit side gusset includes an air lock adapted to permit the boundary layers of air to leave the exit side gusset and also to minimize return of ambient air into the exit side gusset; features of the air locks are disclosed; additional suction means improve the vacuum in the air lock gussets.

Abstract: The operation of paper machines making light weight webs at higher speeds wherein satisfactory drying of the webs is frequently precluded by the occurrence of web flutter within the drier section, is made possible by the provision of floater headers integrated with the hood structure of the Papridrier (T.M.), to provide support to the web substantially throughout its length until a sufficient degree of dryness is reached whereat the web is sufficiently strong to withstand flutter generated forces.

Abstract: The described apparatus has utility as a doctor on a paper machine, as a drying element in an aircap dryer and as a sealing element in such a dryer. It involves a foot portion having an outer surface generally conforming to the curvature of the cylinder surface on which it is used. It is resiliently supported in close juxtaposition to the cylinder surface so that a gap diminishing in thickness towards one longitudinal edge of the foot portion is provided. At least two rows of nozzles communicate through the foot portion in order to project pressurized air into the gap. Each nozzle is angled relative to three orthogonal planes, one of which is tangent to the cylinder surface at the point where the nozzle axis meets the surface, another of which is parallel to the longitudinal edge of the foot portion. The flow from the nozzles is such as to support the foot portion and to seal the support flow from any disorganized flows.

Abstract: Process for promoting uniform and low levels of migration in drying of moist textile webs impregnated with treating agents using cylinder drying machines, by removing the vapor layer formed on the reverse surface of the textile web not contacting the heated cylinders during the continuous passage of the web through the heat transfer zone by suction or transverse blowing over the width of the web. Devices for carrying out this process are described.

Abstract: A drying apparatus suitable for use in the drying of paper web and which comprises a housing, rollers located within the housing for supporting the paper web which is transported through the housing, and means for applying heat to the rollers. The heat is applied directly to the rollers' periphery and at such a level as to cause vaporization of moisture contained within the web, whereby a vapor layer is created between the web and the portion of the rollers' periphery which would otherwise be contacted at any given time by the web.

Abstract: A moisture profiling apparatus is provided for use with continuous running webs, particularly paper but useful for other permeable webs, having a series of adjacent compartments extending transversely of the web guide means and provided with means to selectively vary the quantity, velocity and temperature of gaseous drying medium impinging on the surface of the web, so as to modify variations in the moisture profile transversely of the web. The profiling hood is generally used in combination with a dryer drum, which may be a hollow drum provided with a plurality of transversely extending vacuum chambers and means to control the vacuum conditions in the drum chambers, so as to further modify the flow conditions of the gaseous drying medium, usually air.

Abstract: The low temperature heat recovery system is used in combination with apparatus for drying a moving web of paper or the like and comprises a steam circuit, a gas circuit and a refrigerant circuit. The steam circuit recovers condensed steam from the rotary cylinders of the paper dryer, reheats the steam and injects the steam back into the rotary cylinders or back into the steam main. The gas circuit removes the wet air from the dryer housing, extracts the moisture and the latent heat from the air, reheats the air and injects the air back into the housing. The refrigerant circuit functions as a heat pump to heat the steam and air prior to injecting the steam and air into the cylinders and housing, and cools the air to condense and extract the moisture from the air.

Abstract: An apparatus for improving the surface of a web of printing material for coating or printing including means to "drag" under pressure the web of material over a surface thereby flattening and aligning in a uniform pattern the fibers of a web of printing material.

Abstract: Method and apparatus for drying a moving web utilizing one or more air caps each including an apertured plate together with a high pressure plenum which is arranged to deliver high pressure air through the apertures in the plate to impinge against the web. The geometry of the plates, their spacing from the web and the positioning of exhaust means are correlated to provide a minimum amount of cross flow interference thereby improving the heat transfer and ultimately the efficiency of the drying operation.

Abstract: Apparatus for drying a travelling web, particularly a paper web. A hot air delivery structure is mounted adjacent the periphery of a steam heated cylinder to direct jets of hot air against travelling web supported on the cylinder. At least part of hot air delivery structure is moveable transversely of the cylinder periphery and the jets of hot air produce a surface effect to hold air delivery structure away from engagement with the web. Movement of hot air delivery structure is preferably achieved by flexure of that structure.