Abstract: The present invention relates to extraction bedplates 10, 110, 210, 310, 410, 510, 610 for use in apparatus 5 for defiberizing paper making stock and methods for making such bedplates. Preferred methods for making such bedplates 10, 110, 210, 310, 410, 510, 610 include the step of cutting a disc shaped blank from a metal plate and the step of forming holes 45, 145, 245, 345, 445, 545, 645, 646 either the metal plate or the disc shaped blank. The holes 45, 145, 245, 345, 445, 545, 645, 646 preferably are formed using a cutting stream, most preferably either a laser or a water jet. Use of a such a cutting stream to form the holes facilitates the cutting of holes 45, 145, 245, 345, 445, 545, 645, 646 having non-circular, and preferably tesselatory, cross sections as well as holes 45, 145, 245, 345, 445, 545, 645, 646 extending at acute angles with respect to an axis 20 of the bedplate.

Abstract: The present invention relates to extraction bedplates 10, 110, 210, 310, 410, 510, 610 for use in apparatus 5 for defiberizing paper making stock and methods for making such bedplates. Preferred methods for making such bedplates 10, 110, 210, 310, 410, 510, 610 include the step of cutting a disc shaped blank from a metal plate and the step of forming holes 45, 145, 245, 345, 445, 545, 645, 646 either the metal plate or the disc shaped blank. The holes 45, 145, 245, 345, 445, 545, 645, 646 preferably are formed using a cutting stream, most preferably either a laser or a water jet. Use of a such a cutting stream to form the holes facilitates the cutting of holes 45, 145, 245, 345, 445, 545, 645, 646 having non-circular, and preferably tesselatory, cross sections as well as holes 45, 145, 245, 345, 445, 545, 645, 646 extending at acute angles with respect to an axis 20 of the bedplate.

Abstract: The present invention relates to extraction bedplates (10), (110), (210), (310), (410), (510), (610) for use in apparatus (5) for defiberizing paper making stock and methods for making such bedplates. Preferred methods for making such bedplates (10), (110), (210), (310), (410), (510), (610) include the step of cutting a disc shaped blank from a metal plate and the step of forming holes (45), (145), (245), (345), (445), (545), (645), (646) either the metal plate or the disc shaped blank. The holes (45), (145), (245), (345), (445), (545), (645), (646) preferably are formed using a cutting stream, most preferably either a laser or a water jet. Use of a cutting stream to form the holes facilitates the cutting of holes (45), (145), (245), (345), (445), (545), (645), (646) having non-circular, and preferably tesselatory, cross sections as well as holes (45), (145), (245), (345), (445), (545), (645), (646) extending at acute angles with respect to an axis (20) of the bedplate.

Abstract: Pressure screening apparatus for screening a suspension of paper fiber stock employs a rotor in which a single impulse or foil member is carried or positioned to move along a discrete portion of the screen surface. This arrangement improves efficiency of operation of the pressure screen by reducing the rotational effect of the rotor on the stock suspension being screened and by providing a less disturbed screening region through which the single foil operates. Embodiments are shown in which multiple single impulse elements sweep over discrete portions of a screen and in which a single foil is combined, in screening apparatus, with multiple foils in accordance with the increase in consistency of the stock as it passes through the screen.

Abstract: Improved apparatus for dewatering or washing a suspension of paper pulp in which first and second rolls are rotatably mounted with an endless loop of wire tensioned around the rolls, and in which a headbox delivers a pulp suspension to be thickened or washed and positioned with an outlet to discharge the pulp suspension into or onto the wire as it approaches the first roll, and in which the washed or dewatered pulp is collected after it has passed between the wire and a second roll, in which the first roll has a central shaft, and screw flighting on the shaft formed in left and right-hand sections are terminated at cylindrical discs mounted at opposite ends of the shaft, and in which the screw flighting has a depth which is substantially greater than the maximum thickness of the pulp layer and in which the aggregate open area between the screw flights is substantially greater than the cross-sectional area of the headbox outlet to assure that the spaces between the flights can be no more than partially filled

Abstract: Broke handling and reducing apparatus and method for comminuting a moving continuous sheet or web material such as paper broke in the dryer or converter section of a papermaking machine, includes a plurality of high pressure water jet cutting nozzles mounted in spaced-apart relation transversely to the direction of movement of the material and are mounted so as to direct high pressure cutting jets into the path of movement. The nozzles are mounted so that at least some of the nozzles are cyclically moved with respect to others of said nozzles to form a plurality of mutually intersecting jet cutter paths to reduce the material into a multiplicity of smaller discrete or easily separable pieces.

Abstract: Embodiments of apparatus for thickening a liquid suspension of solid particles, such as papermaking pulp in water, include a pair of spaced apart rolls and a woven wire or plastic wire belt trained around these rolls. The suspension is supplied to the apparatus at the first roll for centrifugal extraction and is carried by the belt to the second roll for further water extraction and thickening, and is then discharged from the apparatus. In one embodiment, the first roll is formed with an open surface, and the suspension is delivered to the web at least partially by flowing through the first roll openings, from either a headbox in the on-running wedge zone or a headbox internal to the rolls to deliver stock outwardly through the roll.

Abstract: A flat bed, Fourdrinier-type, countercurrent washer for cellulosic pulp incorporates a pressing section at the downstream end thereof which includes the couch roll and additional rolls that carry out multiple mechanical pressing operations on the pulp after it has been subjected to multiple stages of displacement washing without mechanical treatment. As a result, where such washers without mechanical pressing deliver pulp of a consistency of the order of 15% solids, this washer increases the pulp consistency to as high as 40% while correspondingly increasing the effectiveness of the washing operation as a whole.

Abstract: A process of preparing a suspension of paper making fibers in water for use in the making of paper includes the steps of treating a mass of fibrous materials, such as shredded waste paper materials, with steam under pressure in a closed vessel, and transferring the resulting mixture of treated materials and steam to a second vessel containing a substantial volume of aqueous liquid in such manner that the mixture impacts directly the liquid in the second vessel at very high velocity causing disintegration of the solid materials into essentially separate fibers and contaminant particles accompanied by dispersion of these solids in the liquid in the second vessel. Systems are described for carrying out these process steps on either a continuous or a batch basis.

Abstract: A cutter for comminuting a moving continuous sheet or web, such as paper broke, in the dryer or converter section of a papermaking machine, includes a plurality of high pressure water jet cutting nozzles positioned in a conduit section for receiving such broke from the papermaking machine. In one embodiment the nozzles are arranged in banks positioned to impact the sheet as it passes through the conduit section, from opposite sides, and are mounted on water conduits which, in turn, are mounted for reciprocating movement and are oscillated transversely of the direction of sheet movement by a mechanical drive. The cutting jets from the high pressure nozzles impact the sheet simultaneously at opposite sides, while being reciprocated to reduce the sheet into a multiplicity of smaller discrete or easily separable pieces which fall through the bottom of the conduit section, for further processing or disposal.

Abstract: A method for thickening a liquid suspension of solid particles, such as papermaking pulp in water, uses a pair of spaced apart rolls and a woven wire or plastic wire belt trained around these rolls. The suspension is supplied at the first roll for centrifugal extraction and is carried by the belt to the second roll for further water extraction and thickening, and is then discharged from the apparatus. In one embodiment, the first roll is formed with an open surface, and the suspension is delivered to the web at least partially by flowing both into and out a roll chamber via the first roll openings, from a headbox in the on-running wedge zone.

Abstract: Apparatus for screening papermaking stock comprises two annular flat screening plates arranged in parallel spaced relation to form a screening chamber therebetween which is bounded on its outer periphery by a cylindrical wall, and wherein a rotor includes vane portions which extend into this screening chamber to agitate the stock so that particles of sufficiently small size can pass through the screening plates into annular compartments outside the screening plates from which they flow into a peripheral chamber having an outlet port. The screening chamber includes an annular space which is surrounded by the accepts chamber and is radially beyond the vane portions of the rotor wherein reject material collects for discharge through an outlet tube which extends through the accepts chamber to the outside of the apparatus.

Abstract: Screen cylinders, and methods of making the same for use in removing contaminant particles from papermaking stock, have a seamless cylinder body and the openings or slots therethrough are formed by directing a focused laser beam at an outer surface while focusing the beam intermediate the outer an dinner surfaces to form an opening or slot with tapered walls. Wear bars may be applied to the inside surface as a bead of weld material. The seamless cylindrical body is formed by centrifugal casting or by cold roller extrusion.

Abstract: In apparatus for thickening a suspension of pulp material which includes an endless foraminous belt wrapping two spaced horizontally supported rolls, a special doctor mechanism is provided for transferring thickened pulp from the bare surface of the second roll into a trough mounted in the space bounded by the two rolls and the upper and lower runs of the belt. More specifically, the doctor mechanism includes a rigid doctor blade mounted with its working edge in close but spaced relation with the bare surface of the roll to remove pulp therefrom without contact with the roll surface. Provision is also made for periodically oscillating the blade about a horizontal axis to move its working edge away from and back to its closely spaced working relation with the roll.

Abstract: In screening apparatus for paper making stock comprising a cylindrical screening member dividing the interior of a pressure housing into a supply chamber and an accepts chamber, and also comprising a rotor mounted for rotation in the supply chamber and including a plurality of vanes mounted thereon in angularly spaced relation with each other and in relatively closely spaced relation with the screening member, each of the vanes is of generally airfoil shape and is oriented with its leading edge closest to the screening member and with the surface portion thereof trailing the leading edge diverging from the screening member to create a positive pressure force along the leading edge followed by a negative pressure force between the trailing portion and the screening member.

Abstract: A screen plate and method of making a screen plate for the pressure screening of papermaking stock in pressure screening apparatus includes slots which have been cut therethrough by a machining laser beam focused at the inlet side of the plate, to provide slots with nearly straight walls with minimum taper, and which are recast and have a "glassy" appearance by reason of the melting and resolidification of the immediate wall surface, to provide a low friction path for the stock. Straight, curved and inclined or slanted slots are disclosed including slots which are at a diagonal to the axis of the cylinder. Slots or openings are disclosed which are inclined to a radius line therethrough both with and against the direction of flow of the stock along the inlet surface. Wear bars are applied to the plate for coaction with the rotating foils on the screening apparatus, in the form of strips of weld material of high hardness applied directly to the plate.

Abstract: A screen plate and method of making a screen plate for the pressure screening of papermaking stock in pressure screening apparatus includes slots which have been cut therethrough by a machining laser beam focused at the inlet side of the plate, to provide slots with nearly straight walls with minimum taper, and which are recast and have a "glassy" appearance by reason of the melting and resolidification of the immediate wall surface, to provide a low friction path for the stock. Straight, curved and inclined or slanted slots are disclosed including slots which are at a diagonal to the axis of the cylinder. Slots or openings are disclosed which are inclined to a radius line therethrough both with and against the direction of flow of the stock along the inlet surface. Wear bars are applied to the plate for coaction with the rotating foils on the screening apparatus, in the form of strips of weld material of high hardness applied directly to the plate.

Abstract: A screen plate and plate and method of making a screen plate for the pressure screening of papermaking stock in pressure screening apparatus includes slots which have been cut therethrough by a machining laser beam focused at the inlet side of the plate, to provide slots with nearly straight walls with minimum taper, and which are recast and have a "glassy" appearance by reason of the melting and resolidification of the immediate wall surface, to provide a low friction path for the stock. Straight, curved and inclined or slanted slots are disclosed including slots which are at a diagonal to the axis of the cylinder. Slots or openings are disclosed which are inclined to a radius line therethrough both with and against the direction of flow of the stock along the inlet surface. Wear bars are applied to the plate for coaction with the rotating foils on the screening apparatus, in the form of strips of weld material of high hardness applied directly to the plate.

Abstract: An apparatus for pulping paper making stock at high consistencies which includes a rotor body having a plurality of vanes extending generally radially outwardly therefrom and a feed screw mounted centrally of the rotor body and extending upwardly therefrom along an axis of rotation of the rotor body. The feed screw includes a conical body having a base with a periphery adjacent root portions of the rotor vanes and at least one helical flight extending along the length of the conical body and, in one embodiment, has a tapered end which is located adjacent a vane root. The rotor body and feed screw are mounted for rotation in a center portion of the bottom wall of a tub for holding paper making stock such that, when the rotor is rotated, the conical body and helical screw guide material contacting the feed screw downwardly and outwardly to contact the rotor vanes which impel the stock toward the side wall of the tub with sufficient force to climb the wall.

Abstract: In screening apparatus for paper making stock including a housing, a cylindrical perforated screen member separating the interior of the housing into a supply chamber and an accepts chamber on the inside and outside respectively of the screen member, an inlet port for supplying stock to one end of the supply chamber, an outlet port from the accepts chamber, a reject port from the supply chamber, and a rotor mounted for rotation within the screen member, the rotor is characterized by comprising a substantially circular disk which is of a thickness constituting a very minor fraction of the axial length of the screen member and has vanes mounted on its outer periphery which extend lengthwise of the screen member for rotation with the disk in the annular space between the periphery of the disk and the inner surface of the screen member.