US4383918A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High turbulence screen
Assignee: Black Clawson Co
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Filing: 1980-05-02
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Granted: 1983-05-17
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Expires: 2000-05-02
Abstract
Abstract Apparatus for screening a suspension of liquid, paper making fibers and undesirable rejects to remove a substantial portion of the rejects therefrom comprise a cylindrical screening member provided with circumferentially extending screening slots in the range of from greater than 0.008 inch to approximately 0.030 inch in width, and bars projecting from the inlet face of the screen and cooperating with rotating foils for creating a field of high intensity, fine scale turbulence adjacent the inlet face of the screen. The paper making fibers and other particles of elongated thin shapes can pass through the screening slots, but relatively chunky reject particles, which would pass through the larger openings of conventional paper making screens, are rejected without fractionation of the paper making stock or appreciable variation in the consistencies of the feed, accepts and reject flows. The apparatus has special utility in a two-stage screening system when installed immediately ahead of the headbox of a paper machine, and also as the primary screen in a waste paper stock preparation system.
Inventors
- 👤 David E. Chupka
- 👤 Peter Seifert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:01
CPC Classifications
D; D21; D21D; D21D5/00; D21D5/02; D21D5/16; B; B07; B07B; B07B1/00; B07B1/18; B07B1/20; D21D5/023; D21D5/026
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
110 words
A pressurized paper making stock screen comprising: a substantially cylindrical screening member having an inlet side and an accepts side, means for feeding under pressure a suspension of liquid, paper making fibers and undesirable reject particles to said inlet side of said screening member, means defining a plurality of through slots in said screening member extending substantially circumferentially thereof, said slots having a narrowest portion of from greater than 0.008 inch to approximately 0.030 inch, means for generating immediately adjacent said inlet side of said screening member a field of high intensity fine scale turbulence, and means for removing from said screen rejects too large to pass through said slots.
Claim 2
Dependent Claim
110 words
A pressurized paper making stock screen comprising: a substantially cylindrical screening member having an inlet side and an accepts side, means for feeding under pressure a suspension of liquid, paper making fibers and undesirable reject particles to said inlet side of said screening member, means defining a plurality of through slots in said screening member extending substantially circumferentially thereof, said slots having a narrowest portion of from greater than 0.008 inch to approximately 0.030 inch, means for generating immediately adjacent said inlet side of said screening member a field of high intensity fine scale turbulence, and means for removing from said screen rejects too large to pass through said slots.
Claim 3
Dependent Claim
61 words
The screen of claim 1 wherein said turbulence generating means comprises: elongated members projecting from said inlet side of said screening member, and means mounted for movement adjacent and parallel with said inlet side of said screening member and said elongated members, said elongated members being of sufficiently large section measured transversely of said cylinder to prevent hairpinning of fibers thereon.
Claim 4
Dependent Claim
19 words
The screen of claim 2 wherein said slots are circumferentially continuous about said screening member and spaced axially thereof.
Claim 5
Dependent Claim
20 words
The screen of claim 3 wherein said screening member comprises a plurality of axially spaced rings defining said slots therebetween.
Claim 6
Dependent Claim
35 words
The screen of claim 3 wherein said screening member comprises a continuous strand wound helically about a central axis with adjacent coils in spaced relation defining said slots therebetween as a substantially continuous helical slot.
Claim 7
Independent Claim
148 words
A system for treating on a continuous basis a suspension comprising liquid, paper making fibers of various lengths, and undesirable particles of both elongated but thin shapes and relatively chunky shapes to remove a substantial portion of said particles from said suspension as reject, comprising: (a) a pair of screening stations arranged to receive said suspension in series, (b) the first of said screening stations including means for rejecting the undesirable particles of elongated but thin shape while accepting the particles of relatively chunky shape having cross-sectional dimensions less than a first predetermined maximum, and (c) the second of said screening stations being connected to receive the accepted stock from said first screening station and including means for rejecting particles of relatively chunky shape having cross-sectional dimensions greater than a second predetermined maximum substantially smaller than said first predetermined maximum while accepting particles of elongated but thin shape.
Claim 8
Independent Claim
148 words
A system for treating on a continuous basis a suspension comprising liquid, paper making fibers of various lengths, and undesirable particles of both elongated but thin shapes and relatively chunky shapes to remove a substantial portion of said particles from said suspension as reject, comprising: (a) a pair of screening stations arranged to receive said suspension in series, (b) the first of said screening stations including means for rejecting the undesirable particles of elongated but thin shape while accepting the particles of relatively chunky shape having cross-sectional dimensions less than a first predetermined maximum, and (c) the second of said screening stations being connected to receive the accepted stock from said first screening station and including means for rejecting particles of relatively chunky shape having cross-sectional dimensions greater than a second predetermined maximum substantially smaller than said first predetermined maximum while accepting particles of elongated but thin shape.
Claim 9
Dependent Claim
101 words
A system as defined in claim 6 wherein said first screening station includes a screen member provided with multiple screen holes of substantially circular shape and a predetermined diameter establishing said first predetermined maximum dimension, and said second screening station includes a cylindrical screening member provided with multiple screening slots extending substantially circumferentially thereof and of substantially greater length than width, said slots having a narrowest portion of a predetermined width substantially smaller than the diameter of said holes to establish said second maximum predetermined dimension and reject relatively chunky particles having a cross-sectional dimension greater than said second predetermined maximum.
Claim 10
Dependent Claim
119 words
A system as defined in claim 6 wherein said second screening station includes a screen comprising: a substantially cylindrical screening member having an inlet side and an accepts side, means for feeding under pressure a suspension of liquid, paper making fibers and undesirable reject particles to said inlet side of said screening member, means defining a plurality of through slots in said screening member extending substantially circumferentially thereof, said slots having a narrowest portion of from greater than 0.008 inch to approximately 0.030 inch, means for generating immediately adjacent said inlet side of said screening member a field of high intensity fine scale turbulence, and means for removing from said screen rejects too large to pass through said slots.
Claim 11
Dependent Claim
64 words
A system as defined in claim 8 wherein said second screening station further comprises: elongated members projecting from said inlet side of said screening member, and means mounted for movement adjacent and parallel with said inlet side of said screening member and said elongated members, said elongated members being of sufficiently large section measured transversely of said cylinder to prevent hairpinning of fibers thereon.
Claim 12
Dependent Claim
34 words
A system as defined in claim 8 wherein said first screening station includes a screen member provided with multiple screen holes of substantially circular shape and a predetermined diameter establishing said predetermined maximum dimension.
Claim 13
Dependent Claim
59 words
A system as defined in claim 9 wherein said first screening station includes a screen member provided with multiple screen holes of substantially circular shape and a predetermined diameter establishing said first predetermined maximum dimension, and wherein said slots in said screening member at said second screening station are circumferentially continuous about said screening member and spaced axially thereof.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-16 | 1986-11-15 | 1987-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-16 | 1990-11-15 | 1991-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-16 | 1994-11-15 | 1995-05-17 | $7700.00 | Window Closed / Lapsed |