Abstract: An apparatus and method for protecting a wood chip destructuring device from damage due to tramp material. The destructuring device includes a pair of destructuring rolls operating a pre-established distance from each other and an infeed chute for delivering a stream of wood chips to pass through a region between the destructuring rolls. Said protection system includes a sensing unit and a control unit to detect tramp material present in the chip stream. If tramp material is detected in the wood chip flow, the protection system operates to further separate the destructuring rolls so that the surfaces of the destructuring rolls will not be damaged by the tramp material as the flow of material passes between the destructuring rolls.

Abstract: A method and apparatus for coating a traveling paper web includes a coating applicator disposed in movably-controlled spaced adjacency with the paper web, which is supported on a rotating backing roll. The coating applicator permits a controlled introduction of a fresh portion of an aqueous slurry of coating material which is mixed with a recirculated portion of coating material in a controlled manner to prevent the formation of large vortices within the coating applicator. The coating material flows successively through mixing, convergent, and recirculation channels, all of which are defined on one side thereof by a distinct surface of a flow stabilizer which is positioned centrally in a cavity in the coating apparatus.

Abstract: A cleaning apparatus is disclosed for cleaning a forming wire extending around a wire turning roll of a paper machine. The apparatus includes a shower which is disposed upstream relative to the turning roll for spraying a cleaning liquid onto the forming wire. A housing is disposed between the shower and the turning roll, the housing being connected to a source of pressurized air. The housing defines an opening which has a first and a second end. The housing also defines an orifice which has an upstream and a downstream end for permitting a flow therethrough of the pressurized air such that the flow of air is directed against the wire for at least partially removing the cleaning liquid therefrom. The opening cooperates with the turning roll such that the opening conforms with the turning roll for substantially sealing the opening against loss of the pressurized air so that the flow of pressurized air is directed through the orifice.

Abstract: A controlled crown roll utilizes a crown support piston with a glide shoe with a cavity in the face of the glide shoe centered under the nip loading line. The cavity is surrounded by a land area, the majority of which is located away from the nip load. Use of a low viscosity hydraulic fluid, for example, 15.6 cP, with a hydraulic film thickness of 0.002 inches, results in significantly lower friction between the glide shoe and the interior surface of the rotating mantle. Recesses in the piston sides form hydrostatic thrust bearings which perform the centering function for the piston and the glide shoe.

Abstract: The press section of a papermaking machine has two conventional presses followed by two or three presses including one heated Extended Nip press thereby allowing control of the two-sidedness of the web by balancing the temperature and pressure of the Extended Nip Press with the pressure and temperature of the additional presses to form a one-sided sheet. The use of smooth high temperature press felts can aid in the reduction of two-sidedness of the formed web. The dryer section may alternatively add a fifth press utilizing the first dryer roll as the backing roll, two Extended Nip presses, a heated Extended Nip press followed by a heated conventional press, or a heated Extended Nip press in the third pressing position followed by a conventional heated press utilizing the first dryer as the backing roll.

Abstract: A winding machine for winding webs, such as paper webs which may be longitudinally slit, has two support rollers (TW1 and TW2) that carry the roll being produced (R; R'; R", R"') in a winding bed formed between the support rollers. Both support rollers have elastic casings (M1 and M2) which are however deformable to a different extent. One of the support rollers is partially surrounded by the web during winding. In order to further optimize the winding quality, even in the case of heavy wound web rolls, the support roller (M1) subjected to the highest total load, that results both from static and dynamic loads during winding, has the most elastically deformable casing. Such a winding machine is preferably developed so that the space (DR) delimited by both support rollers (TW1 and TW2) and the already partially produced wound web roll (R) is sealed as much as possible at its ends and from below. An overpressure can be generated in the space (DR) for relieving the inherent weight of the roll (R).

Abstract: In a pulp washing method which employs a dilution stage, followed by an extraction stage, and followed, in turn by a dilution stage, filtrates from the extraction stage and the displacement stage are segregated so that at least a part of the filtrate from the extraction stage may be removed from the pulp washing.

Abstract: An applicator head is positioned beneath a backing roll and has a housing divided into three sections. A first coating pond is defined between an overflow barrier and a first wall. A converging plate extends between the first wall and a second wall, and converges toward the substrate, and a second pond is defined between the plate and an end wall. Coating is introduced to both ponds. A low pressure cavity is defined beneath the converging plate and between the first wall and the second wall. The cavity opens to the second pond, and draws air and excess coating from the second pond. The substrate is prewetted as it passes through the first pond, and coating deprived of entrained air is applied to the substrate in the second pond. Coat weight uniformity and increased machine speeds are thus achievable.

Abstract: A blanket passes over a concave shoe which is urged against a backing roll to form a press nip. The ends of the blanket are attached to circular heads. The transition from the nip-imposed cardioid shaped to the circular shape maintained by the heads results in a region of the blanket subject to fatigue. The heads are mounted on journals for motion between inboard stops and outboard stops which are spaced apart approximately 4 inches in the cross machine direction. Positioning of the heads on the journals is controlled by four hydraulic pistons mounted between the support beam and each head. Multiple hydraulic systems are controlled to extend the life of the blanket by alternating between holding the back head fixed and letting the front head float and fixing the front head and letting the back head float.

Abstract: An applicator head is positioned beneath a backing roll over which a substrate can be drawn. The applicator head has a housing which contains a pond of coating material between an up machine overflow lip and a down machine extraction plate or premetering plate. Coating material at a relatively low velocity flows into the pond adjacent to the overflow lip. The premetering plate extends radially from the coating inlet to a position proximate to and converging with the backing roll, where it premeters the amount of coating applied to the substrate. The premetering plate preferably has a plurality of holes through which coating and air are drawn. A metering element is spaced downstream of the premetering plate, and a low pressure area is constructed therebetween. Air and coating are drawn from the low pressure area through a valve, and the pressure thereby controlled.

Abstract: A multiplicity of teeth are mounted to a beam in a comb structure, with the space between the teeth defining slots. The edges of the slots are lined with upstanding flanges which are sharpened to form cutting edges. The comb structure is arranged to be substantially parallel to an array of bag breaking bars. The bars interdigitate with the teeth and thus pass through the narrow openings between the teeth where the knife edges scrape the bars, thereby cutting free any material adhering to or impaled upon the bag breaking bars. Alternatively, an apparatus for cleaning a bag breaker has a pivotally mounted are having a fork which is aligned to receive a bar between the tines of the fork. The fork engages the base of the bar and then proceeds to slide up the bar as the forward motion of the bar causes the arm to pivot. In this way, material impaled upon a bar is slid or scraped upwardly towards the top of the bar.

Abstract: The Extended Nip press apparatus of this invention has an endless loop nip blanket which is clamped at each end head by a circular array of twelve clamp segments which are positioned radially by the hydraulic actuation of an axially positionable circumferential clamp ring. The blanket is separately sealed by an air tube seal which extends between the clamp ring and the interior of the blanket. Because the clamping arrangement is independent of the seal, inadvertent loss of air pressure will not cause the blanket to become unclamped.

Abstract: An apparatus for filtering suspensions is provided with rotatable annular vertical disks (4) covered with filter material and partly submerged in the suspension to be filtered. Each disc is provided with a number of cells (22) for receiving filtrate from the suspension as the disc is rotated. The cells of each disc communicate with a central filtrate chamber (7) via respective accumulation chambers (30) formed by wall means (31) in the filtrate chamber. Each accumulation chamber of each disc extends axially past the disc and has an outlet (32) which also extends axially past the disc. The advantage is that a more concentrated coarse fraction of the suspension can be achieved.

Abstract: A refiner plate has bars integrally formed with the refiner plate base member which have discrete regions of selected physical properties. A material possessing the physical property is deposited in a reservoir in the bar, such as a groove. The reservoir may be positioned in the top of the bar and may be of various shapes. Alternatively, the reservoir with material is positioned on the bar leading or trailing edge. Alternatively, an abrasive surface extends over the entire upper surface of the bar including the leading and trailing edges. The bar may be formed of a white iron alloy which is heat-treated to form a soft matrix with embedded carbide grains. By protecting regions of desired smoothness with a wear-resistant protective coating flow is preserved in selected areas.

Abstract: A method and apparatus for cooling wood pulp, coming from a high temperature bleaching stage at a consistency of approximately 10%, prior to introducing the wood pulp to a low temperature bleaching stage, including the steps of exposing the pulp to a thickening press in order to extract sufficient liquor from the pulp to increase the consistency to more than 25%; fluffing the pulp and depositing it on a moving bed cooler having a provision for blowing air through the pulp; and blowing cooling air through the pulp by using an air pump device with appropriate ducting. By first thickening the pulp, the mass of pulp to be cooled is significantly reduced and energy savings proportionate to the mass reduction are realized.

Abstract: An expandable mandrel including a threaded spindle with a drive for rotating the spindle, wedge pieces supported on the spindle with core chuck lugs facing outwardly for engaging the inner surface of a core, the wedge pieces having outwardly facing inclined cam surfaces, matching cam surfaces on the core chuck lugs to expand the core chuck lugs when the wedge pieces are moved relatively axially by the spindle, the wedge pieces and core chuck lugs being free to rotate with the spindle until locked by an annular gear and a stopping rack so that the wedge pieces and core chuck lugs are held against rotation to allow the spindle to rotate relatively thereby moving the wedge pieces axially and the core chuck lugs outwardly.

Abstract: A rotary drum filter valve is provided with a valve having a valve segment with a first part which partially restricts the flow of filtrate from a head section and a second part which blocks from the head section.

Abstract: Air entrained within the pond of a coating applicator is influenced toward a designated region for removal. The region is formed by a recessed air collector which sets up a high-recirculation, low-pressure zone within the pond. Entrained air bubbles migrate to the collector. The collected air and excess coating is drawn out of the collector cavity by a plurality of perforations which discharge to a collection cavity at a lower pressure or partial vacuum. The collector structure may be employed in various coater/size press configurations.

Abstract: The top and bottom felts at the web transfer between two dryer sections in a single tier papermaking dryer are spaced by pivoting the vacuum roll over which the felt and web move. The vacuum roll is mounted to two pivot arms which are driven by inflatable air rides to alternately incline the roll toward the downstream felt, forming a sandwich of the two felts and the web, and to a spaced position. The short motion of the vacuum roll allows standard felt stretchers to be used, and permits rapid adjustment of the felt spacing.

Abstract: The top and bottom felts at the web transfer between two dryer sections in a single tier papermaking dryer are spaced by pivoting the vacuum roll over which the felt and web move. The vacuum roll is mounted to two pivot arms which are driven by inflatable air rides to alternately incline the roll toward the downstream felt, forming a sandwich of the two felts and the web, and to a spaced position. The short motion of the vacuum roll allows standard felt stretchers to be used, and permits rapid adjustment of the felt spacing.