Recovery of fibers from a fiber processing waste sludge
First Claim
Patent Images
1. A process of recovering fibers comprising:
- providing a waste sludge from a waste paper recycling facility comprising a plurality of previously de-fibered, individual fibers and fines;
placing said waste sludge in a first vessel;
bringing an interior of said vessel and said waste sludge to an elevated temperature and pressure;
maintaining said elevated temperature and pressure for an effective time interval;
discharging said waste sludge from said first vessel to a second vessel, said second vessel being sufficiently vented to maintain a pressure drop during said discharge step, and to thereby provide a treated sludge product comprising treated fibers and fines;
passing said treated sludge through a separator to separate and collect a portion of said treated fibers and said treated fines from said sludge.
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Abstract
A process of recovering a useful population of fibers and fines from the waste stream of fiber processing facility is disclosed. Steam explosion of the fiber-containing waste stream is used to increase the separation efficiency of the fibers from the ash. The steam explosion also enhances the quality of the recovered fibers and fines, providing a population of recovered fibers which can be incorporated into the fiber component of a tissue or absorbent paper product.
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Citations
20 Claims
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1. A process of recovering fibers comprising:
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providing a waste sludge from a waste paper recycling facility comprising a plurality of previously de-fibered, individual fibers and fines;
placing said waste sludge in a first vessel;
bringing an interior of said vessel and said waste sludge to an elevated temperature and pressure;
maintaining said elevated temperature and pressure for an effective time interval;
discharging said waste sludge from said first vessel to a second vessel, said second vessel being sufficiently vented to maintain a pressure drop during said discharge step, and to thereby provide a treated sludge product comprising treated fibers and fines;
passing said treated sludge through a separator to separate and collect a portion of said treated fibers and said treated fines from said sludge. - View Dependent Claims (2, 3, 4)
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5. A process of converting waste fibers comprising:
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providing a waste stream comprising a mixture of previously de-fibered, individual fibers from a fiber processing facility;
exposing said waste stream to an elevated temperature and pressure;
releasing rapidly said pressure from said waste stream, thereby providing a plurality of treated fibers within a treated waste stream; and
separating said treated fibers from said waste stream, said treated fibers having improved fiber properties than an untreated population of de-fibered, individual fibers. - View Dependent Claims (6, 7, 8, 9, 10)
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11. A process of converting waste fibers comprising:
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providing a waste stream from a de-fibering operation of a paper making or paper recycling facility, comprising a mixture of a plurality of individual fibers;
exposing said waste stream to an elevated temperature and pressure;
releasing rapidly said pressure from said waste stream, thereby providing a plurality of treated fibers within a treated waste stream; and
separating said treated fibers from said waste stream. - View Dependent Claims (12)
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13. A process of improving the useful properties of fibers comprising:
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providing a first supply of individual and disassociated fibers, said fibers contained within a waste stream from a paper fiber processing operation;
subjecting said waste stream containing said individual and disassociated fibers to an elevated temperature;
discharging said waste stream at an elevated temperature from a first pressure environment to a second pressure environment, said first pressure being greater than said second pressure;
separating a portion of said individual and disassociated fibers from said waste stream, thereby providing a second supply of fibers, said second supply of fibers having improved fiber qualities than untreated fibers. - View Dependent Claims (14, 15, 16, 17, 18)
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19. A process of recovering fibers from waste paper recycling sludge comprising:
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providing a waste sludge consisting essentially of a plurality of individual fibers, and individual fines;
placing said waste sludge in a first vessel;
bringing an interior of said vessel and said waste sludge to an elevated temperature and pressure;
maintaining said elevated temperature and pressure for an effective time interval;
discharging said waste sludge from said first vessel to a second vessel, said second vessel being sufficiently vented to maintain a pressure drop during saiddischarge step, and to thereby provide a treated sludge product comprising treated fibers and fines;
passing said treated sludge through a separator to separate and collect a portion of said treated fibers and said treated fines from said sludge.
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20. A process of recovering fibers and fines from a waste sludge comprising:
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providing a source of individual fibers and fines said source consisting essentially of a waste sludge from a fiber processing facility;
placing said waste sludge in a first vessel;
bringing an interior of said vessel and said waste sludge to an elevated temperature and pressure;
maintaining said elevated temperature and pressure for an effective time interval;
discharging said waste sludge from said first vessel to a second vessel, said second vessel being sufficiently vented to maintain a pressure drop during said discharge step, and to thereby provide a treated sludge product comprising treated fibers and fines;
passing said treated sludge through a separator to separate and collect a portion of said treated fibers and said treated fines from said sludge.
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Specification