US3004876A - Method for washing fibrous material - Google Patents

Method for washing fibrous material Download PDF

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Publication number
US3004876A
US3004876A US647276A US64727657A US3004876A US 3004876 A US3004876 A US 3004876A US 647276 A US647276 A US 647276A US 64727657 A US64727657 A US 64727657A US 3004876 A US3004876 A US 3004876A
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Prior art keywords
washing
barrel
liquor
liquid
enclosure
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Expired - Lifetime
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US647276A
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English (en)
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Carl W Zies
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International Basic Economy Corp
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International Basic Economy Corp
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Priority to US647276A priority Critical patent/US3004876A/en
Priority to FR858132A priority patent/FR1287721A/fr
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    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/02—Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B9/00—Presses specially adapted for particular purposes
    • B30B9/02—Presses specially adapted for particular purposes for squeezing-out liquid from liquid-containing material, e.g. juice from fruits, oil from oil-containing material
    • B30B9/12—Presses specially adapted for particular purposes for squeezing-out liquid from liquid-containing material, e.g. juice from fruits, oil from oil-containing material using pressing worms or screws co-operating with a permeable casing
    • B30B9/16—Presses specially adapted for particular purposes for squeezing-out liquid from liquid-containing material, e.g. juice from fruits, oil from oil-containing material using pressing worms or screws co-operating with a permeable casing operating with two or more screws or worms
    • B30B9/163—Presses specially adapted for particular purposes for squeezing-out liquid from liquid-containing material, e.g. juice from fruits, oil from oil-containing material using pressing worms or screws co-operating with a permeable casing operating with two or more screws or worms working in different chambers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B9/00—Presses specially adapted for particular purposes
    • B30B9/02—Presses specially adapted for particular purposes for squeezing-out liquid from liquid-containing material, e.g. juice from fruits, oil from oil-containing material
    • B30B9/26—Permeable casings or strainers
    • B30B9/267—Strainer bars; Spacers

Definitions

  • theseliquids for example black liquors that exist ina paperpulp mill, may be washed from fibers with excessive volumes of water in equipment known as vacuum drum washers.
  • meehanicalscrew presses now employed for deliquifying of .fibrous .materials in .paper mills fall into two classifications; .the first classification consists of thosegpresses which candewater a 'fibrousmaterial to a pressed pulp containingapproximately 65% moisture.
  • presses .in this classification are -.employed, three or four different presses in .series normally constitute a .washsystem wherein fresh water is added to the fiber material:ahead of, for example, the fourth press in the line.
  • the second classification consists of those presses which can dewater a fibrous material to approximately 40% moisture.
  • One of wthesepresses alone is capable of removing approximately 70% of the contaminating liquor from a fibrous material 'wherein higher degrees of removal of contaminants is required.
  • Two different-presses in this classification used in series constitutes-awash systern 'whereinfresh water is added to the fiber material ahead of the second press in'the' line.
  • One object ofthis invention is to.provide.methods.for introducing operating liquids under pressure into the workingconfines of the barrel ofacontinuous mechanical screw press.
  • a further object of this invention is to obviate the necessity of multiple units in a multi-stage washing system.
  • a further object of this invention is to provide methods for washing of liquors from fibrous materials with .a minimum amount of dilution water.
  • a further object'of this invention is tolprovide methods for introducing a working liquid or a digesting .liquorQ into a.preceding zone of a mechanical screw press barrel and mechanically extracting .this same liquid and/ or liquor in a. succeeding zone of the screw press barrel.
  • Thisproblem consists of transporting the digested chips in a large volume of 'the digestion liquor through pumpsv and pipelines, whichofnecessitymustbe "fabricated of non-corrosive material such as stainless steel because of :the'corrosive natureof-these liquors.
  • FIG. 'l isaview partlyin verticalsection andpar tly in side elevation, showing a working assembly suitable foruse 'in'the performance of theimetho'dsherein disclosed, including vertical and horizontal screw pressbarthe recovery of digestion, liquor (black liquor).
  • the general type of apparatus is familiar to those skilled rels and associated elements.
  • FIGS. 1A and 1B For convenience in illustration, because the complete assembly is extensive, several parts of said assembly have been cut away and are shown in FIGS. 1A and 1B as follows:
  • FIG. 1A is a drawing, partly in section and partly in side elevation, showing feeding anddriving mechanism for the vertical press barrel, the plane of separation between FIGS. '1 and 1A being along the broken line A-A in both said figures;
  • FIG. 1B is a drawing, partly in section and partly in side elevation, showing driving mechanism for the horizontal barrel, and other associated elements, the line of separation between FIGS. 1 and 1B being along the plane BB in both said figures;
  • FIGS. 2, 3 and 4 are sectional views taken respectively on the lines 22, 33 and 44 of 'FIG. I;
  • FIG. 1 shows a screw press assembly wherein a material such as neutral sulfite semichemically digested wood chips may be processed for Since in the art, I will describe only briefly the broad function and purpose of some of the main elements of the structure.
  • the screw press (assembled views l,'1A and 1B) includes feeding means (FIG. 1A) comprising a horizontal rotatable shaft carrying a helical worm 11, the shaft and worm being enclosed in a tubular housing 12 which.
  • Shaft 10 is driven from cooperating sprockets 17 which in turn are driven by a motor, not shown.
  • Shaft 15 is. driven from motor 18 through a gear reduction train in housing 19, and then through a worm and gear or a bevel gear and pinion to shaft 15, this driving gear. being conventional and therefore not shown.
  • chute 14 Forming a downward continuation of chute 14 is a vertical barrel section 22 -(FIG. 1) coaxial and coextensive with chute 14. This barrel section will be more explicitly described hereinbelow.
  • Shaft 15 continues downwardly through barrel section 22, and carries there on a plurality of screw hubs 24, 25, 26, 27, 28, 29 and 30, each having its respective helical screw flight thereon, .the periphery of which closely. approaches the inner face of the barrel wall. 1
  • an imperferate collar 23 within which-the advancing material is compacted into a liquid-seal plug by gradually increasing viouslyrecognized in the art, for example by decreasing 4 the pitch of screw flights 36 towards the left end, or by increasing the shaft root diameter towards the left, or by restricting the escape opening within an automatic choke assembly 37.
  • This automatic choke assembly is not shown in detail, but structural features of one suitable embodiment are well shown and described inU.S. Patent No. 1,752,054 to Raymond T. Anderson.
  • rotation of a worm 38 produces co-acting rotation of a peripheral gear which through the operation of further cooperating parts results in the'constriction of inner peripheral parts so as to produce a change in the diameter of a choke aperture somewhat similar to the operation of the so-called iris diaphragm which is used in there is a short space .59 where the material movement some optical elements, for example certain camera lenses.
  • barrel zone 22 will be better understood by reference to prior patents to Raymond T. Anderson, including for example, U.S. Patents Nos. 1,722,882, and 1,773,771;
  • This vertical barrel part is built up from an assembly of barrel bars 43, lying side by side (FIG. 2) and all fitted together in keystone-like fashion, having V-shaped spring clips 44 therebetween, 'and .tightly maintained by semicircular frame members 45 and 46 which in turn are clamped longitudinally by bars 47, transversely retained by tie bolts 48.
  • the barrel bars 43 are disposed in such close mutual lateral contact as to prevent solid material from escaping radially outwardly therebetween, but to permit liquid to be squeezed through theminute interstices when the pressure is heavy.
  • the spacesbetween the barrel bars may be adjusted depending on the fibrous material being pressed. 4 7
  • Zone 23 of the vertical barrel might 'be termed the sealing? zone since no drainage occurs therefrom and the plug therein formed provides a liquid seal for liquids originating in thehorizontal barrel as will appear.
  • this extension of the sealing zone may be 'obtained by assembling two semicylindrical portions of tubing in the lower section of prepress zone 22 in place of the barrel bars norm-ally employed. This same effect may be attained merely by using barrel bars in this same area without spacers between the bars;
  • Each branchpipe feeds into a respective apertureextending radially inwardly through a knife bar, the disposal being such .that the liquid is discharged into the barrel near the shaft surface.
  • 'Each branch pipe is provided with a'valve 75 for possible individual control.
  • the right portion of the horizontal barrel of this embodiment may'therefore be'termed the wash liquid injection portion.
  • a deflecting shield 67 prevents the concentrated liquor issuing from zone 22 from intermingling with washed liquors issuing from the washing section of the horizontal barrel 66 and pressing section 34.
  • a collecting trough 79 collects liquors from the horizontal barrel which issue from the screw press by means of pipes 76, and from this trough they proceed to intermittent storage tanks (not shown). This arrangement of concentrated liquor and wash liquor separation is utilized wherein a multi-stage two-press system is employed. If a multi-stage singlepress system is employed, baflle hown in FIG. 1 for separation of concentrated liquor and wash liquor are not employed.
  • the fibrils continue onwardly in the barrel towards the automatic choke 37 and the 'dischargepoint 41. In'its trip through the horizontal barrel the material hasbeen simultaneously exposed to mechanical expression and water washing, and each effect supplements the other.
  • By controlling the temperature within the barrel which can be done by pressure control and/or supplemental heating means, along with the multi-stage washing means'thus provided, very eificient' washing of fiber bundles and fibers is attained.
  • the apparatus above-described and shown in the drawings can be modified in varioushelpful ways for specific purposes merely 'by further consideration of the operations already described.
  • the vertical barrel or at least the drainage portion thereof may be made longer to provide more drainage space and more liquor removal during the preliminary pressure application. Since a wide range of fibrous materials can be processed in this apparatus, it is recognized that it will be desirable toprepress a greater quantity of liquor from fibrous materials which originally contain a greater quantityof liquor. For example, in
  • barrel injection sections may he, therefore, employed 'whereinmaterials that absorb wash liquids or give up liq- .uor' fractions with diificulty' are being processed.
  • the entire horizontal barrel may be lengthened by '1 'to 3 feet, or more,.as required by materials that give up contained contaminants with difii-
  • neutral sulfite'semichemically digested aspen wood chips were processed in the apparatus .of this invention as illustrated in 1.6 pounds of .water were employed for every one pound .of fiber on the oven dry weightbasis.
  • the digested wood chips processed contained 32.2% soluble solids on the dry weight basis.
  • the fiber bundles thus produced contained only '6;5%.soluble's0lids on a dry weightbasis.
  • a second control 'test another quantity of the same .neutral sulfite semichemically digested aspen wood chips were pressed in the mechanical screw press not employingthe novel washing means of this invention.
  • the fiber. bundles from this control test contained 11.75% soluble solids on the dry basis, or almost double the .quantity as that when the methods of this invention were practiced.
  • a third test was conducted wherein the neutral sulphite semichemically digested chips were pressed in a first stage press so that the resultant fiber bundles contained 50% moisture. 1.2 pounds of water per pound of oven dry solubles free fiber was then continuously added to the pressed fibers from the first press as they were being conveyed to a second press. The second press operation was so conducted that the fiber bundles were also pressed to a material containing 50% moisture. The resultant fiber bundles from this test contained only 250 pounds of solubles per ton of D. solubles free fiber.
  • a fourth test was then conducted employing the methods and means of this invention whereby 1.2 pounds of water heated to a temperature of 150 was pumped into six ports of the horizontal barrel as illustrated by pipe lines 76, FIG. 1, per pound of oven dry solubles free fiber. The press was so operated that the resultant fiber bundles also contained 50% moisture.
  • the resultant fiber bundles contained 250 pounds of solubles per ton of CD. solubles free fiber.
  • This high hydrostatic head of wash water on the pulp in process not only permits an extremely rapid rate of diffusion of the wash water into the fiber bundles, but also permits the filling of voids between fiber bundles withwater instead of air as the fiber bundles continue their passage along the horizontal barrel of the apparatus 7 shown in FIG. 1.
  • FIG. 5 I illustrate schematically an arrangement in'which the horizontal barrel is equipped with alternate wash and drainage sections so arranged as to furnish direct counter current washing within the same horizontal barrel.
  • the showing of FIG. 5, while simply schematic, will be clearly understandable to one now familiar with FIGS. 1 t0 4,
  • Neutral sulphite semichemically digested chips with black liquor entrained therein areintroduced into the 'vided with a shaft 53 having screw flights 54 thereon and is shown as having drainage sections 84, 85 and 86 alternating with sections 87, 88, and '89 which are non-drainage or solid wall sections.
  • trough 850 From trough 850 the liquid is advanced by pump 57 through line 93 into the first wash section 89 at the entry end of the horizontal barrel, and again it is carried one step to the left into drainage section 86aud then is squeezed into trough 86a.
  • the liquor now having been considerably enriched with black liquor, is pumped through pipe 94 by pump 58 to the original point of entry 81 of digested chips, and discharged into the feed conveyor 80.
  • a fair proportion of the excess concentrated liquor is expressed in the travel through the vertical barrel. This may be collected in a trough 95 and pumped through pipe 96 by pump 61 to any convenient disposal point.
  • FIG. 6 is a schematic showing of a multi-stage, multipress washing system, although in this particular instance, for simplicity, two stages are indicated in the drawing. Obviously the system can be enlarged to any extent desired by the use of additional units or stages.
  • fresh water is pumped by pump P through pipe 100 to wash section 101'ofthe second press enclosed in broken lines 102.
  • the efiluent from sections 101 and 103 is collected in drainage pan 104 and advanced by pump P through pipe 105 to prepress section 106 of the vertical barrel.
  • the liquors drained from section. 106 are intercepted'fby pan 107 and are advanced by pump P to the wash section 108 of the press enclosed in broken lines 109, the first press in this series.
  • the liquors collected in drain pan 112 from the wash and press sections 108 and 111 of this first press 109 are advanced by pump P from pan 112 through pipe 113 to vertical pre-press barrel 114.
  • the liquors collected in drain pan represent the total wash effluent from the multi-stage pressing system just described, and these liquors are pumped by pump P to an evaporator or to any end use ormeans of disposal known in the art.
  • Each ofthe wash sections 101 and 108 may represent any plurality of stages, for example between two and twelve stages.
  • each of the screw presses in the present series (FIG. 6) may be equipped with a counterflowwash system within each press.
  • a countercurrent, multi-stage washing would, of course, be more efiicient, than for example a pair of presses in series with only single point introduction of wash water in each of the presses.
  • wash liquids may be pumped into either a vertical or a horizontal barrel at points other than through the knife bar lugs illustrated in FIG. 1.
  • water could be pumped into the barrel at any point on the periphery of the barrel, or it could be pumped to the barrel at either end of the barrel, but, of course, preferably to the feed end of the barrel.
  • the most efficient use of wash liquors is only attained when these liquors are pumped to the innermost parts of the materials being processed in the barrel of the screw press as is accomplished through the means and methods of this invention.
  • the processes described herein may be facilitated or accelerated by subjecting the conglomerate mass of liquor-bearing material to planned variations in temperature as it moves through the horizontal barrel. Such variations may be achieved, for example, by injecting steam through injection nozzles similar to those shown herein for injecting wash liquid, and the steam may be developed either at atmospheric pressure or may be super-heated to higher temperatures and pressures. Since rates of diffusion are increased with temperature, the values of the methods and means of this application may be enhanced by conducting the washing thus attained at temperatures above room temperature. For example, because of a mechanical pressure imposed upon the pulp Within the apparatus of FIG. 1 and because of the hydrostatic pressures that may be employed, it may attain values as high as 5,000 p.s.i.
  • Water under these pressures may be heated above 212 for injection into the apparatus of this invention.
  • a further illustration of the use of temperatures by injection of steam or super heated water by the methods and means of this invention may be illustrated by a commercial scale processing of waste papers for dispersion of asphalt bodies.
  • steam under 150 p.s.i. pressure has been injected into the vertical barrel of the apparatus shown in FIG. 1 to increase the temperature of the waste paper pulp before it reaches the transition section 59 shown in FIG. 1.
  • a waste paper pulp initially at 100 F. may be raised to a controlled temperature, for example 165 to 200 F., depending upon the requirements of the subsequent operations to be conducted in the horizontal barrel of the press.
  • the wash water temperature can also be varied, and additional injections of water at any desired temperature can be made at any desired points along the barrel.
  • a method of washing residual digestion liquor from a digested mass of fibrous material comprising passing said material through an elongated enclosure from an entry end to a discharge end thereof, applying pressure continuously to the material in a direction adapted to simultaneously compact the material and assist in moving it in the direction aforesaid, arranging said enclosure into a series of operating sections, each section consisting of a washing zone and a drainage zone, providing apertures in the enclosure wall in registry with each drainage zone, injecting liquid into each washing zone, collecting drained liquid which escapes through the apertures in each drainage zone, re-injecting the collected liquid-liquor solution into a respective washing zone in a section nearer to the entry end of the enclosure whereby to establish a flow of washing liquid gradually increasing in liquor concentration in a direction counter to the direction of movement of the material being washed, prepressing the material to remove a relatively readily removable fraction of liquor from the material, continuously charging the prepressed material into said enclosure, and injecting into the material being prepressed the drainage liquid from a drainage
  • a method of washing residual digestion liquor from a digested mass of fibrous material comprising passing said material through an elongated enclosure from an entry end to a discharge end thereof, applying pressure to the material in a direction adapted to simultaneously compact the material and assist in moving it in the direction aforesaid, injecting a wash liquid into a zone of said enclosure near said entry end, said wash liquid being capable of leaching out said liquor, injecting steam into said enclosure between said entry end and the zone where said wash liquid is injected, and providing drain apertures in a drainage wall portion of said enclosure through which the aforesaid pressure drives the solution of liquid and liquor.
  • a method of washing residual digestion liquor from a digested mass of fibrous material comprising passing said material through an elongated enclosure from an entry end to a discharge end thereof, applying pressure continuously increasing to between 1000 p.s.i. and 5000 p.s.i. to the material in a direction adapted to simultaneously compact the material and assist in moving it in the direction aforesaid, injecting a wash liquid into a zone of said enclosure near said entry end, said wash liquid being capable of leaching out said liquor, and providing drain apertures in a drainage wall portion of said enclosure through which the aforesaid pressure drives the solution of liquid and liquor.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
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US647276A 1957-03-20 1957-03-20 Method for washing fibrous material Expired - Lifetime US3004876A (en)

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US647276A US3004876A (en) 1957-03-20 1957-03-20 Method for washing fibrous material
FR858132A FR1287721A (fr) 1957-03-20 1961-04-08 Perfectionnements aux procédés de lavage des matières fibreuses

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US647276A US3004876A (en) 1957-03-20 1957-03-20 Method for washing fibrous material
FR858132A FR1287721A (fr) 1957-03-20 1961-04-08 Perfectionnements aux procédés de lavage des matières fibreuses

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3207293A (en) * 1962-11-05 1965-09-21 Robert C White Vibratory conveyor with inversion diverter
US3360400A (en) * 1961-06-07 1967-12-26 Ajem Lab Inc Method for power washing, surface reforming and the like
US4611612A (en) * 1984-05-01 1986-09-16 Chicagoland Processing Corp. Apparatus for continuously treating solids with liquids
EP0139736B1 (fr) * 1983-04-13 1987-06-16 ANDERSSON, Alf Ove Procede de lavage de pulpe
WO1990002224A1 (fr) * 1988-08-19 1990-03-08 Sprout-Bauer, Inc. Presse de lavage de la pate
WO1995015412A1 (fr) * 1993-11-30 1995-06-08 Dxresources Corporation Systeme de desencrage de papier journal au moyen d'un dispositif d'extraction a contre-courant

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2451963A1 (fr) * 1979-03-22 1980-10-17 Creusot Loire Procede et installation de preparation et de lavage d'une pate a papier a partir d'une matiere lignocellulosique reduite en morceaux

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US604348A (en) * 1898-05-17 Cooking and pressing apparatus
US1933609A (en) * 1932-02-17 1933-11-07 J O Ross Engineering Corp Multiple stage pulp washer
US2308883A (en) * 1937-07-15 1943-01-19 Chemical Seed Treating And Del Process for the treatment of cotton seed and the like
US2761799A (en) * 1953-11-09 1956-09-04 Schroeder Otto Method of and apparatus for washing labeled bottles and separating labels from the wash liquid
US2784725A (en) * 1953-04-30 1957-03-12 Standard Oil Co Crystal-washer apparatus

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US604348A (en) * 1898-05-17 Cooking and pressing apparatus
US1933609A (en) * 1932-02-17 1933-11-07 J O Ross Engineering Corp Multiple stage pulp washer
US2308883A (en) * 1937-07-15 1943-01-19 Chemical Seed Treating And Del Process for the treatment of cotton seed and the like
US2784725A (en) * 1953-04-30 1957-03-12 Standard Oil Co Crystal-washer apparatus
US2761799A (en) * 1953-11-09 1956-09-04 Schroeder Otto Method of and apparatus for washing labeled bottles and separating labels from the wash liquid

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3360400A (en) * 1961-06-07 1967-12-26 Ajem Lab Inc Method for power washing, surface reforming and the like
US3207293A (en) * 1962-11-05 1965-09-21 Robert C White Vibratory conveyor with inversion diverter
EP0139736B1 (fr) * 1983-04-13 1987-06-16 ANDERSSON, Alf Ove Procede de lavage de pulpe
US4611612A (en) * 1984-05-01 1986-09-16 Chicagoland Processing Corp. Apparatus for continuously treating solids with liquids
WO1990002224A1 (fr) * 1988-08-19 1990-03-08 Sprout-Bauer, Inc. Presse de lavage de la pate
US4915830A (en) * 1988-08-19 1990-04-10 Sprout-Bauer, Inc. Pulp wash press
WO1995015412A1 (fr) * 1993-11-30 1995-06-08 Dxresources Corporation Systeme de desencrage de papier journal au moyen d'un dispositif d'extraction a contre-courant
US5520780A (en) * 1993-11-30 1996-05-28 Dxresources Corporation Method and apparatus for de-inking newsprint using counterflow extractor

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