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Title: Shearing means for penetrating pulp stock on Fourdrinier machine
Claims: I claim: 1. An improved method of making paper utilizing a Fourdrinier paper making machine, comprising the following steps: supplying a paper stock having a consistency greater than 1/2% and less than 21/2% to a Fourdrinier fabric whereby a pulp stock web is formed on the fabric; dewatering the pulp stock web to a consistency between 2% and 51/2%; applying a shearing action to fiber bundles and flocs situated in the web by shearing means at a location where the consistency of the web is between 2% and 51/2%, thereby upsetting the fibers and redistributing them substantially in a horizontal plane and smearing the flocs; removing additional water from the pulp stock web downstream from the location where the shearing action is applied to the web; and removing the web from the Fourdrinier fabric and directing the web to pressing and drying sections of the paper making machine. 2. A method according to claim 1, wherein the consistency after initial dewatering of the pulp stock web at the location of the application of the shearing action is between 2 and 4%. 3. A method according to claim 2, including the steps of subjecting the web to a first low vacuum suction immediately upstream of the location where the shearing action is applied to the web in order to maintain the consistency of the web between 2% and 4% at the location of the shearing means. 4. A method according to claim 3, including the step of subjecting the web to a second low vacuum suction immediately downstream of the location where the shearing action is applied to the web, the second low vacuum suction providing rapid resetting of bottom fibers situated adjacent a lower surface of the pulp web, and drawing down in rapid sequence, fibers situated in a liquid suspension above the bottom fibers as the pulp web is further drained. 5. A method according to claim 3, wherein the first low vacuum suction is operated under a vacuum of between 10 and 40 inches of water. 6. A method according to claim 5, wherein the first low vacuum suction is operated under a vacuum of between 10 and 20 inches of water. 7. A method according to claim 4, wherein the second low vacuum suction operates under a vacuum of between 14 and 22 inches of water. 8. In a paper making machine having an endless Fourdrinier fabric having an upper run and a lower run, the fabric extending between a breast roll and a couch roll, a headbox situated adjacent the breast roll at an upstream end of a forming section of the machine, the headbox having a slice at a lower end thereof for discharging pulp stock onto an upper surface of the fabric, table rolls or foils, or both, being situated immediately beneath an upper run of the fabric, and suction boxes being located immediately beneath the fabric and downstream of the table rolls or foils for effecting further removal of water from a web formed from the pulp stock on the upper surface of the fabric, the improvement comprising shear means situated above an upper surface of the top run of the fabric such that a lower portion of the shear means is adapted to penetrate a pulp stock web situated on the Fourdrinier fabric; the shear means being operated by an external means supplying power, which drives the shear means at a surface speed exceeding a linear speed of the fabric by greater than 3% and less than 8% of the speed of the fabric; the shear means being situated at a location where a consistency of the pulp stock web situated on the fabric is between 2% and 51/2%; the shear means providing a shearing action to fiber bundles and flocs situated in the pulp stock web as the pulp stock web passes between the shear means and the fabric, whereby the re-working the pulp stock web and re-forming the fiber network and smearing the flocs thereof. 9. For use in a paper making machine according to claim 8, wherein said shear means comprises a top shear roll, wherein the surface speed of the top shear roll exceeds the linear speed of the fabric by greater than 3% and less than 5% of the linear speed of the fabric. 10. In a paper making machine according to claim 9, wherein the shear means is a top shear roll and the consistency at the top shear roll is between 2% and 4%. 11. In a paper making machine according to claim 10, the top shear roll having annular end pieces fastened thereto and support trunnion ring bearings, a drive cog wheel being secured to one of the trunnion ring bearings, the trunnion ring bearings rotatably supporting the top shear roll in a pair of spaced-apart enclosed trunnions, each trunnion having a trunnion support ring carrying a plurality of rotatably mounted trunnion wheels about the periphery thereof, the trunnion wheels engaging a respective trunnion ring bearing; one end of each trunnion support ring being pivotally mounted and an other end thereof being movably supported in a substantially vertical direction by means of fluid actuated telescoping means, the telescoping means permitting vertical adjustement of the top shear roll relative to the upper surface of the top run of the fabric. 12. In a paper making machine according to claim 10, wherein a first low vacuum suction means is situated immediately upstream of the top shear roll beneath the fabric, the first low vacuum suction means adapted to maintain the consistency of the pulp stock web between 2 and 4% as the pulp stock web passes beneath the top shear roll, the first low vacuum suction means being operated under a vacuum of between 10 and 40 inches of water. 13. In a paper making machine according to claim 12, wherein a second low vacuum suction means is situated beneath the fabric immediately downstream of the top shear roll, the second low vacuum suction means adapted to rapidly reset bottom fibers in the pulp stock web and draw down in rapid sequence fibers and liquid suspension above the bottom fibers as the pulp stock web is further drained, thereby facilitating release of the pulp stock web from the fabric downstream of the top shear roll. 14. In a paper making machine according to claim 11, wherein the top shear roll is of light weight, rigid tubular construction made up of sheet metal rings supported by a grid work of spirally positioned body wires, the roll having a surface deck comprising closely spaced spirals of wires wound over longitudinal supporting rods set into peripheries of the sheet metal rings, the spirals of the surface deck being covered by a wire screen, the wire screen having a coarse mesh between 8 and 24 strands per inch. 15. In a paper making machine according to claim 12, wherein the first low vacuum suction means immediately upstream of the top shear roll comprises an upstream sheet stabilizing suction box, the upstream sheet stabilizing suction box having a slotted cover having a wear-resistant inserts and adapted to operate under a vacuum of between 10 and 40 inches of water. 16. In a paper making machine according to claim 13, wherein the second low vacuum suction means comprises a downstream sheet stabilizing suction box having a wear-resistant slotted cover, the downstream sheet stabilizing suction box adapted to operate under a vacuum between 14 and 22 inches of water. 17. In a paper making machine according to claim 10, wherein a spray pan collector is situated adjacent to and downstream from the top shear roll. 18. An improved method of making paper utilizing a Fourdrinier paper making machine, comprising the following steps: supplying a paper stock having a consistency slightly greater than 2% to a Fourdrinier fabric whereby a pulp stock web is formed on the fabric; dewatering the pulp stock web to a consistency between 2% and 51/2%; applying a shearing action to fiber bundles and flocs situated in the web by shearing means at a location where the consistency of the web is between 2% and 51/2%, thereby upsetting the fibers and redistributing them substantially in a horizontal plane and smearing the flocs; removing additional water from the pulp stock web downstream from the location where the shearing action is applied to the web; and removing the web from the Fourdrinier fabric and directing the web to pressing and drying sections of the paper making machine. Other info: Inventors: Hansen, Victor E. (Jacksonville, FL, US) Application Number: 791943 Filing Date: 1977-04-28 Publication_date: 1979-03-20 Assignee: JWI Ltd. (Montreal, CA) Primary Class(es): 162/210 162/217, 162/313, 162/314, 162/364, 162/DIG7 Other Classes: US Patent Ref:
Other Refs:
Primary Examiner: Fisher, Richard V. Assistant Examiner: Attorney: Brown; Charles E. |
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