US3873410A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for recovering paper fibers from waste paper containing materials
Assignee: Black Clawson Co
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Filing: 1973-08-27
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Granted: 1975-03-25
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Expires: 1993-08-27
Abstract
Abstract Waste paper containing materials, e.g., commercial ''''waste paper'''' or municipal waste, are treated for recovery of reusable paper therefrom by slushing in a pulper followed by screening of the entire output extracted from the pulper, with or without an intermediate centrifugal cleaning operation, in a screen having fine perforations sized to accept only substantially fully defibered paper. The reject flow from this screen is maintained at an adequately high rate, e.g., 20-80% to assure freedom from blocking of the screen perforations. A deflaker is connected to receive this reject flow, and the output of the deflaker is separated by a tailing screen into accepts which are recycled to the primary screen and rejects which are eliminated from the system. Major advantages of this method and system include the use of only one piece of apparatus for each of the essential operations of pulping, screening and deflaking, the elimination of low specific gravity reject from the system at a single station, and distribution of power requirements in such manner that the ratio of pulping power to deflaking power is 1.5 or less.
Inventors
- 👤 David E Chupka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:15
CPC Classifications
D; D21; D21B; D21B1/00; D21B1/02; D21B1/026; D21B1/04; D21B1/12; D21B1/30; D21B1/32; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/64; Y10; Y10S; Y10S241/00; Y10S241/38
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
172 words
THE METHOD OF TREATING MATERIALS CONTAINING WASTE PAPER TO RECOVER PAPER FIBERS THEREFROM FOR REUSE WHICH COMPRISES THE STEPS OF: A. SUPPLYING SAID MATERIALS AND WATER TO A VESSEL AT RATES MAINTAINING THE CONSISTENCY OF THE RESULTING SUSPENSION IN THE RANGE OF APPROXIMATELY 2-8%, B. CONTINUOUSLY PULPING SAID SUSPENSION IN SAID VESSEL TO REDUCE SAID MATERIALS TO FRAGMENTS, C. CONTINUOUSLY EXTRACTING FROM SAID VESSEL A SLURRY COMPRISING LIQUID AND SUCH OF SAID FRAGMENTS AS WILL PASS THROUGH HOLES OF THE ORDER OF 1/2 TO 2 INCHES IN DIAMETER, D. SUBJECTING SAID SLURRY TO SCREENING THROUGH RELATIVELY FINE PERFORATIONS SIZED TO ACCEPT ONLY SUBSTANTIALLY FULLY DEFIBERED PAPER WITHOUT PRELIMINARY SCREENING THEREOF, E. CONTROLLING THE ACCEPTED AND REJECTED FLOWS FROM SAID SCREENING STEP TO MAINTAIN AT LEAST APPROXIMATELY 20% OF THE SOLID MATERIALS IN SAID SLURRY IN THE RESULTING REJECTED FLOW, F. SUBJECTING SAID FLOW OF REJECTED MATERIALS TO A DEFIBERING ACTION, G. SUBSTANTIALLY ELIMINATING FROM THE RESULTING DEFIBERED MATERIALS THE NON-FIRBOUS CONSTITUENTS THEREOF, AND H. RESUBJECTING THE REMAINING MATERIAL TO SAID SCREENING STEP.
Claim 2
Independent Claim
172 words
THE METHOD OF TREATING MATERIALS CONTAINING WASTE PAPER TO RECOVER PAPER FIBERS THEREFROM FOR REUSE WHICH COMPRISES THE STEPS OF: A. SUPPLYING SAID MATERIALS AND WATER TO A VESSEL AT RATES MAINTAINING THE CONSISTENCY OF THE RESULTING SUSPENSION IN THE RANGE OF APPROXIMATELY 2-8%, B. CONTINUOUSLY PULPING SAID SUSPENSION IN SAID VESSEL TO REDUCE SAID MATERIALS TO FRAGMENTS, C. CONTINUOUSLY EXTRACTING FROM SAID VESSEL A SLURRY COMPRISING LIQUID AND SUCH OF SAID FRAGMENTS AS WILL PASS THROUGH HOLES OF THE ORDER OF 1/2 TO 2 INCHES IN DIAMETER, D. SUBJECTING SAID SLURRY TO SCREENING THROUGH RELATIVELY FINE PERFORATIONS SIZED TO ACCEPT ONLY SUBSTANTIALLY FULLY DEFIBERED PAPER WITHOUT PRELIMINARY SCREENING THEREOF, E. CONTROLLING THE ACCEPTED AND REJECTED FLOWS FROM SAID SCREENING STEP TO MAINTAIN AT LEAST APPROXIMATELY 20% OF THE SOLID MATERIALS IN SAID SLURRY IN THE RESULTING REJECTED FLOW, F. SUBJECTING SAID FLOW OF REJECTED MATERIALS TO A DEFIBERING ACTION, G. SUBSTANTIALLY ELIMINATING FROM THE RESULTING DEFIBERED MATERIALS THE NON-FIRBOUS CONSTITUENTS THEREOF, AND H. RESUBJECTING THE REMAINING MATERIAL TO SAID SCREENING STEP.
Claim 3
Dependent Claim
36 words
The method defined in claim 1 including the step of controlling the power requirements for said pulping and defibering step to establish a ratio of not more than approximately 1.5 of pulping power to defibering power.
Claim 4
Dependent Claim
21 words
The method defined in claim 1 wherein said screening and defibering steps are carried out without substantial dilution of said slurry.
Claim 5
Dependent Claim
29 words
The method defined in claim 1 including the step of subjecting said extracted slurry to centrifugal cleaning to remove high specific gravity materials therefrom, prior to said screening step.
Claim 6
Dependent Claim
20 words
The method defined in claim 1 wherein said fine perforations are slots of the order of 0.022 inch in width.
Claim 7
Dependent Claim
21 words
The method defined in claim 1 wherein said fine perforations are circular holes of the order of 0.062 inch in diameter.
Claim 8
Dependent Claim
178 words
The method defined in claim 1 wherein said screening and controlling step comprises the component steps of: a. continuously supplying said extracted slurry to one end of a supply chamber having as one wall thereof a cylindrical screen member having multiple slots therethrough extending generally parallel with the axis thereof, b. maintaining a pressure difference from said supply chamber to the accepts side of said screen member to cause passage of accepted material through said slots, c. causing the slurry in said supply chamber to form a tubular layer of substantial thickness and of substantially the same length as said screen member immediately adjacent the surface of said screen member in said supply chamber, d. creating a substantially tangentially oriented hydraulic shear field in said tubular layer of slurry with shear rates sufficiently high to cause elongated particles to be aligned generally tangentially of said screen member and thereby to flow past rather than through said slots, and e. continuously removing from the other end of said screen chamber approximately 20-80% of said slurry including such elongated particles.
Claim 9
Dependent Claim
173 words
The method defined in claim 1 wherein said screening and controlling step comprises the component steps of: a. continuously supplying said extracted slurry to one end of a supply chamber having as one wall thereof a cylindrical screen member having multiple substantially circular perforations therethrough, b. maintaining a pressure difference from said supply chamber to the accepts side of said screen member to cause passage of accepted material through said perforations, c. causing the slurry in said supply chamber to form a tubular layer of substantial thickness and of substantially the same length as said screen member immediately adjacent the surface of said screen member in said supply chamber, d. creating a substantially tangentially oriented hydraulic shear field in said tubular layer of slurry with shear rates sufficiently high to cause elongated particles to be aligned generally tangentially of said screen member and thereby to flow past rather than through said perforations, and e. continuously removing from the other end of said screen chamber approximately 20-80% of said slurry including such elongated particles.
Claim 10
Dependent Claim
191 words
Apparatus for treating materials containing waste paper to recover paper fibers therefrom for reuse, comprising: a. pulping means including a tub, b. means for supplying said materials and water to said tub at rates maintaining the consistency of the resulting suspension in the range of approximately 2-8%, c. means for continuously pulping said suspension in said tub to reduce said materials to fragments, d. means for continuously Extracting from said tub a slurry comprising liquid and such of said fragments as will pass through holes of the order of 1/2 to 2 inches in diameter, e. screen means connected to receive said slurry and having relatively fine perforations sized to accept only substantially fully defibered paper, f. means for controlling the accepted and rejected flows from said screen means to maintain at least approximately 20% of the solid materials in said slurry in the resulting rejected flow, g. defibering means connected to receive the resulting rejected materials from said screen means, h. a tailing screen connected to receive the resulting defibered materials and to eliminate non-fibrous constituents therefrom, and i. means for recycling the remaining fibrous material to said screen means.
Claim 11
Dependent Claim
191 words
Apparatus for treating materials containing waste paper to recover paper fibers therefrom for reuse, comprising: a. pulping means including a tub, b. means for supplying said materials and water to said tub at rates maintaining the consistency of the resulting suspension in the range of approximately 2-8%, c. means for continuously pulping said suspension in said tub to reduce said materials to fragments, d. means for continuously Extracting from said tub a slurry comprising liquid and such of said fragments as will pass through holes of the order of 1/2 to 2 inches in diameter, e. screen means connected to receive said slurry and having relatively fine perforations sized to accept only substantially fully defibered paper, f. means for controlling the accepted and rejected flows from said screen means to maintain at least approximately 20% of the solid materials in said slurry in the resulting rejected flow, g. defibering means connected to receive the resulting rejected materials from said screen means, h. a tailing screen connected to receive the resulting defibered materials and to eliminate non-fibrous constituents therefrom, and i. means for recycling the remaining fibrous material to said screen means.
Claim 12
Dependent Claim
28 words
Apparatus as defined in claim 9 further comprising centrifugal cleaning means connected between said tub and said screen to remove high specific gravity materials from said extracted slurry.
Claim 13
Independent Claim
185 words
The method of treating materials containing waste paper to recover paper fibers therefrom for reuse which comprises the steps of: a. supplying said materials and water to a vessel at rates maintaining the consistency of the resulting suspension in the range of approximately 3-5%, b. continuously pulping said suspension in said vessel to reduce said materials to fragments, c. continuously extracting from said vessel a slurry having a consistency of approximately 3-5% of such of said fragments in liquid as will pass through holes of the order of 1 inch in diameter, d. subjecting said slurry to screening through relatively fine perforations sized to accept only substantially fully defibered paper without preliminary screening thereof, e. controlling the resulting accepted and rejected flows from said screening step to maintain at least approximately 20% of the solid materials in said slurry in said rejected flow, f. subjecting said flow of rejected materials to a defibering action at a consistency not less than said pulping consistency, g. substantially eliminating from the resulting defibered materials the non-fibrous constituents thereof, and h. resubjecting the remaining materials to said screening step.
Claim 14
Independent Claim
185 words
The method of treating materials containing waste paper to recover paper fibers therefrom for reuse which comprises the steps of: a. supplying said materials and water to a vessel at rates maintaining the consistency of the resulting suspension in the range of approximately 3-5%, b. continuously pulping said suspension in said vessel to reduce said materials to fragments, c. continuously extracting from said vessel a slurry having a consistency of approximately 3-5% of such of said fragments in liquid as will pass through holes of the order of 1 inch in diameter, d. subjecting said slurry to screening through relatively fine perforations sized to accept only substantially fully defibered paper without preliminary screening thereof, e. controlling the resulting accepted and rejected flows from said screening step to maintain at least approximately 20% of the solid materials in said slurry in said rejected flow, f. subjecting said flow of rejected materials to a defibering action at a consistency not less than said pulping consistency, g. substantially eliminating from the resulting defibered materials the non-fibrous constituents thereof, and h. resubjecting the remaining materials to said screening step.
Claim 15
Dependent Claim
29 words
The method defined in claim 11 wherein said paper-containing materials comprise municipal solid waste, and said fine perforations are circular holes of the order of 0.050-0.079 inch in diameter.
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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) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |