US3873412A - Mechanically refining a mixture of kraft and semichemical pulp - Google Patents

Mechanically refining a mixture of kraft and semichemical pulp Download PDF

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Publication number
US3873412A
US3873412A US456455A US45645574A US3873412A US 3873412 A US3873412 A US 3873412A US 456455 A US456455 A US 456455A US 45645574 A US45645574 A US 45645574A US 3873412 A US3873412 A US 3873412A
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United States
Prior art keywords
pulp
hot
kraft
temperature
mixture
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Expired - Lifetime
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US456455A
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English (en)
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Michael T Charters
Franklin E Landis
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Sprout Bauer Inc
Bauer Brothers Co
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Bauer Brothers Co
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Application filed by Bauer Brothers Co filed Critical Bauer Brothers Co
Priority to US456455A priority Critical patent/US3873412A/en
Priority to CA217,492A priority patent/CA1051151A/en
Priority to FI750031A priority patent/FI750031A/fi
Priority to SE7500167A priority patent/SE7500167L/xx
Priority to JP966375A priority patent/JPS5313001B2/ja
Priority to US05/548,288 priority patent/US3989588A/en
Application granted granted Critical
Publication of US3873412A publication Critical patent/US3873412A/en
Assigned to SPROUT-BAUER, INC., reassignment SPROUT-BAUER, INC., MERGER (SEE DOCUMENT FOR DETAILS). EFFECTIVE DATE JULY 9, 1987 Assignors: SWM CORPORATION, MERGED INTO BAUER BROS. CO. CHANGED TO
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    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
    • D21B1/00—Fibrous raw materials or their mechanical treatment
    • D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
    • D21B1/12—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by wet methods, by the use of steam

Definitions

  • This invention relates to new and unique means and methods for producing a relatively low cost, high quality pulp for use in making kraft type products such as linerboard and bag grade paper.
  • the present-invention not only provides means and methods for extending the available supply of pulp for kraft type products but also enables a substantial reduction in the cost of producing such a pulp and improves its quality.
  • Embodiment of the invention provides an arrangement of apparatus enabling a pulping process featuring a mixture of defiberized wood chips, which may be derived from a variety of waste type materials, with a conventional kraft stock.
  • the wood chips either in a raw or weakly impregnated condition, are steamed, pressure refined in a disc refiner, and, while still hot, mixed with hot kraft pulp and hot black liquor.
  • the lignin which coats the disc refined fibers is reacted with the unused chemicals remaining in the black liquor.
  • the composite fiber mixture so obtained can then be conventionally refined and screened and washed either before or after refining.
  • the equipment and controls of the invention system are so arranged as to minimize the production of steam and the use of chemical liquors.
  • the net result is a most economical and effective procedure for providing a homogeneous pulp mixture eminently suited for use in making high quality kraft type products which have improved strength characteristics.
  • a primary object of the invention is to provide improvements in apparatus and procedures for producing a quality pulp suited for use in making kraft type products such as linerboard and bag type paper.
  • Another object of the invention is to provide a kraft quality pulp product comprising a mixture of conventional kraft fibers and fibers derived from woods not normally accepted or workable as kraft materials.
  • a further object of the invention is to provide means and methods of making kraft quality pulp which are economical to employ, more efficient and satisfactory in use and adaptable to a wide variety of applications.
  • Another object of the invention is to provide a workable procedure for employing low cost groundwood type materials in producing a kraft quality pulp.
  • An additional object of the invention is to provide means and methods for producing a new pulp suitable for use in kraft type products possessing the advantageous features, the inherent meritorious characteristics and the means and mode of use herein described.
  • FIG. 1 is a diagrammatic showing of a preferred installation for practicing a process embodying the concepts of the present invention
  • FIG. 2 shows a modification of the installation and procedure illustrated in FIG. 1;
  • FIGS. 3-5 diagrammatically illustrate further modifications of the installation and procedure of FIG. 1 which employ basic concepts of the present invention.
  • FIG. 1 of the accompanying drawings includes, in part and in series relation, a screw press 10, a steaming vessel 12, a disc type refiner 14, a centrifugal separator 16 and a mixing tank 18.
  • a blow tank 20 is connected to receive hot kraft stock and attendant black liquor from a batch type di gester (not shown) and to discharge such stock to the mixing tank 18 by way of a conduit 22.
  • the latter incorporates a pump 24, the control of which will determine the rate of feed of the hot kraft stock and black liquor to the tank 18.
  • a pump 26 is incorporated in a conduit 28 which connects at its entrance end to the mixing tank 18.
  • the discharge end of the conduit 28 connects to a disc type refiner 30 which is in a series relation with a screen 32 and a washer 34.
  • a series related refiner 30 There may be one or more series related refiners 30, screens 32 or washers 34. This will depend on the particular application of the invention system.
  • raw wood chips which may be derived from what is normally considered as scrap or waste materials, are first fed into the screw press 10.
  • a conventional screw press may be employed but it is preferred that the press 10 be one such as known as an Impressafiner, a product manufactured by The Bauer Bros. Co. of Springfield, Ohio, USA.
  • the impressionafiner the wood chips are successively compressed and expanded to remove resins and contained liquids and partially defiberized by this procedure.
  • the pressed chips are subjected to an application of a small amount of liquid conditioning chemical, the nature of which depends on the desired physical characteristics of the end product sought.
  • the conditioning chemical employed may be NaOH, Na- S, NaOI-I Na S, Na Sx (polysulfide), or the like.
  • the pre-treated chips are then moved through a pressure sealing valve 11 to the steam chamber defined in the vessel 12.
  • the chips are retained in the steam chamber for a period of two to ten minutes during which they are continuously advanced to a discharge station from which they are directed to the inlet of the disc refiner 14.
  • the refiner 14 will provide a pressurized environment for the partially defiberized and pre-conditioned chips. It is noted that a double revolving disc refiner is preferred, though a sin gle disc refiner will function satisfactorily for some applications of the invention system and process.
  • the chips In passing through the steam chamber in the vessel 12 the chips will be subjected to elevated pressures from to 150 p.s.i.g. and correspondingly to elevated temperatures and at consistencies from to 40 percent.
  • a similar environment will prevail in the refiner 14 as the chips are passed between opposed refiner discs (not shown), one of which revolves relative the other.
  • the chips Under influence of the discs and the pressurized conditions in the refiner 14, maintained by the provision of a valve 13 in a discharge line 15 extending from the refiner to the tangential inlet of the centrifugal separator 16, the chips are converted primarily into individual fibers coated with lignin and small fiber bundles loosely held together by a lignin bond. As the chips are re noted, the resultant fibers and fiber bundles and attendant free liquor are blown past the valve 13 to the inlet of the separator 16. Entering the inlet of the separator 16 together with these fibers is a measured amount of black liquor delivered by way of conduit 17 and through the medium of a pump 19. The suction side of pump 19 connects with a liquor recovery line 21 which connects in turn with the washer or washers 34 at the end of the invention system. The liquor will cause the pulp fibers which enter the separator to assume a dilute slurry form.
  • the temperature of the liquor introduced to the separator should be maintained between 140F. and 212F. It is most important for best per formance to keep the temperature of the liquor within the separator close to 212F., to insure an optimal reaction on the fibers by the residual chemicals in the hot black liquor and the maintenance of the fibers at an elevated temperature during and after the conventional cyclone separating procedure in the separator 16.
  • the fibers produced in the refiner 14 are further chemically treated in the separator 16 by hot black liquor which moves therewithfrom the underflow end of the separator to the mixing tank 18.
  • the blow tank 20 is connected with a digester containing a batch of conventional kraft pulp. Once the kraft materials in the digester are properly digested, the resultant pulp stock is delivered to the blow tank. The temperature of this stock and that in the mixing tank 18 is controlled by the delivering of metered amounts of hot black liquor. This liquor has its source in the liquor recovery line 21 and is furnished under the influence of pump 19 through branches 23 and 25 of the conduit 17. As noted in FIG. 1, a branch 27 of conduit 17 can be used to supply black liquor to the refiner 14, if so desired.
  • the pressure refined fiber products originating in the refiner 14 will be continuously mixed with the hot kraft pulp.
  • the latter is delivered from the blow tank 20 at a uniform rate so as to achieve a desired proportion of conventional kraft pulp to the disc refined pulp.
  • the mixing takes place in the presence of hot black liquor, the temperature of which, as noted previously, is kept close to 212F. It is significant that the pressure refined pulp will essentially be individual fibers, so that they are continuously exposed to the residual chemical in the hot black liquor and the reaction thereon by the chemical will be continuous throughout the entire process.
  • the proportion of the disc refined pulp mixed with the conventional hot kraft pulp will preferably becontrolled so that it will be between 5 and 25 percent of the total pulp production.
  • the amounts combined will depend on the required end product strength, bulk, brightness, printability, stiffness, etc. Practice indicates that the most practical pulp produced per the invention will have a disc refined fiber content of 10 to 15 percent. lt appears at this time that if this disc refined fiber content is increased to 25 percent, a new line of kraft type products will be enabled by the present invention.
  • the resulting savings of 71 ton of wood per day represents a 3.9 percent wood savingsv At a wood cost of $23 per ton, this represents a yearly (350 days) savings of approximately $571,000. Higher percentages of high yield pulp would, of course, increase the saving in wood usage.
  • the high black liquor temperatures employed per the invention not only improves the conditioning of the pressure refined fibers but they also improve the economics of operating evaporators in a conventionally associated chemical recovery system.
  • FIG. 2 of the drawings shows an installation which is identical to that shown in and described with reference to FIG. 1 except that the screw press 10 and the pre impregnation procedure effected therein is eliminated.
  • the raw chips will be first steamed and the rest of the procedure will be as previously described.
  • the system will be completely adquate for preparing pulp for use in kraft type products. This is due to the fact the chemical reaction enabled by use and application of hot black liquor as described is highly effective to control the physical characteristics of the desired end product.
  • FIG. 3 shows a modification of the system of FIG. 1 wherein the screw press and mixing tank 18 are both eliminated.
  • the centrifugal or cyclone separator 16 is so placed that its underflow end discharges the disc refined materials in the form of fibers chemically treated by hot black liquor, as previously described, directly to the blow tank 20.
  • the rate of feed of hot kraft pulp from the kraft digester to the blow tank will be maintained at a uniform level.
  • an automatic mixture will inherently take place.
  • a continuous cooking effect results as the residual chemicals in the black liquor in the blow tank react on the intermixed fibers.
  • the black liquor should be kept at a temperature in the range from about I40F. to 250F.
  • FIG. 3 is not preferred since the control factors are not as well defined as in the other described embodiments of the invention. However, the resultant pulp will be well suited for lesser quality kraft type products and advantages of the basic concept of the invention are still retained.
  • the conventional blow tank 20 would not be required for steam separation. In such case the kraft pulp could be discharged, in a metered flow, directly to the tank 18.
  • FIG. 4 of the drawings differs from that of FIG. 2 only in that the hot kraft stock is not combined with the disc refined stock in the tank 18 but in the course of a merging flow in the conduit 28.
  • conduit 22 is eliminated and replaced by a conduit 32 which directs the hot kraft stock from the blow tank 20 to the discharge conduit 28 at a point immediately following a pump 26.
  • the latter is incorporated in the conduit 28 to induce a pressured flow of stock from the tank l8 to the following disc refiner 30.
  • FIG. 5 ofthe drawings differs from that of FIG. 4 in that the cyclone separator 16 and the mixing tank 18 have been eliminated and replaced by a dilution tank 40.
  • the delivery line 17, which carries hot black liquor is provided with two branches 42 and 44 which connect the line with the tank 40.
  • the branches 42 and 44 embody control valves 41 and 43 and are connected to respectively discharge into the upper and lower ends of the tank 40.
  • the fiber stock created in the refiner 14, as previously described, is discharged directly to the tank 40 wherein pressure is carefully controlled.
  • black liquor of a proper temperature must be introduced to the case of the refiner 14, in the course of the disc refining procedure, in an amount sufficient to cause condensation of most of the steam which may occur during the refining operation.
  • the disc refined fibers are embodied in a body of hot black liquor to which liquor may be added, as required, below the level of the liquid in the tank, by way of the branches 42 and 44.
  • the dilute slurry form of the disc refined fibers which have been reacted with hot liquor in the dilution tank is channeled to the conduit 28 to be flowed therethrough under pressure.
  • a control valve 29 is incorporated in the conduit 28 in a following relation to the pump 27.
  • the blow tank 20 is connected to the conduit 28 by way of a conduit 45 in which is incorporated the pump 24 followed by a control valve 46. The discharge end of the conduit 45 connects into the conduit 28 immediately following the valve 29.
  • this last described disc refining is followed by screening and washing of a suitable and conven tional nature.
  • the resultant stock mixture, as washed, is directed to storage and/or immediately forwarded for further use while the hot black liquor remaining after washing is recovered and transmitted from the. washers by way of a line 21 into which is connected the hot liquor delivery line 17.
  • the invention provides a simple but unique process of extending conventional kraft stock which results in a high quality pulp usable for a great variety of kraft type products. Not only are economies inherent in the system and answers to problems which have been prevalent in the art as described, but the invention appears to have developed the possibility ofnew products which are basically kraft type products.
  • a process of producing a pulp suited for use in the manufacture of kraft type products, for example linerboard and bag grade paper comprising the steps of steaming small segments of fibrous material, defiberizing the same and elevating the temperature thereof and while the defiberized materials are still at elevated temperature mixing them with a hot kraft pulp and me chanically refining the mixture so obtained.
  • a process of producing pulp as in claim 1 characterized by elevating the temperature of said defiberized material by subjecting the same to a hot black liquor having a temperature in the range of 140F. to 250F. prior to mixing thereof with said hot kraft stock.
  • a process of producing pulp as in claim 2 characterized by applying said hot black liquor at a temperature in the neighborhood of 212F.
  • a process of producing pulp as in claim 1 wherein, immediately following the defiberizing of said steamed segments, the said defiberized material is introduced to a vessel with hot black liquor and in said vessel subjected with said liquor to a centrifugal separation action, in the course of which the fibers of said defiberized material are subjected to the chemical content of said liquor and caused to achieve and maintain an elevated temperature and then discharge and in a continuing movement thereof combine with the hot kraft stock to produce said mixture which is then further refined.
  • a process of producing pulp as in claim 6 wherein the said segments of fibrous material, following defiberizing thereof, are discharged to a blow tank which commonly receives said hot kraft stock and the mixture so produced is subjected to an application of hot black liquor at a temperature in the range of F. to 250F. to maintain the temperature of said defiberized material and react thereon in the course of flow therewith to refiner means wherein the mixture so obtained is subjected to a further refining procedure and the resultant stock forwarded for screening and washing.
  • a process of producing pulp as in claim 6 wherein following the centrifugal separating action said defiberized material at elevated temperature is introduced to a vessel wherein additional hot black liquor is added to maintain it at an elevated temperature and have the chemical content react thereon and then the resultant mixture is flowed to a further refiner means and in the course of its flow the hot kraft stock is introduced thereto to merge and mix therewith in movement to said further refiner means wherein the resulting mixture is subjected to refining as a composite to result in an intermingled pulp product.
  • a process of producing pulp as in claim 11 char acterized by mixing the defiberized segments with hot kraft pulp in hot black liquor at a temperature of [40F. to 250F.

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  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Mechanical Engineering (AREA)
  • Paper (AREA)
US456455A 1974-04-01 1974-04-01 Mechanically refining a mixture of kraft and semichemical pulp Expired - Lifetime US3873412A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US456455A US3873412A (en) 1974-04-01 1974-04-01 Mechanically refining a mixture of kraft and semichemical pulp
CA217,492A CA1051151A (en) 1974-04-01 1975-01-07 Apparatus and process for producing kraft type pulp
FI750031A FI750031A (xx) 1974-04-01 1975-01-07
SE7500167A SE7500167L (xx) 1974-04-01 1975-01-08
JP966375A JPS5313001B2 (xx) 1974-04-01 1975-01-22
US05/548,288 US3989588A (en) 1974-04-01 1975-02-10 Apparatus for producing kraft type pulp

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US456455A US3873412A (en) 1974-04-01 1974-04-01 Mechanically refining a mixture of kraft and semichemical pulp

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JP (1) JPS5313001B2 (xx)
CA (1) CA1051151A (xx)
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SE (1) SE7500167L (xx)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4060450A (en) * 1972-09-01 1977-11-29 Westinghouse Electric Corporation High yield saturating paper
US4145246A (en) * 1976-07-19 1979-03-20 Crown Zellerbach Corporation Process for making high-strength, high-yield sulfite-modified thermomechanical pulp and a linerboard composition produced therefrom
US4294653A (en) * 1974-09-23 1981-10-13 Mo Och Domsjo Aktiebolag Process for manufacturing chemimechanical cellulose pulp in a high yield within the range from 65 to 95%
US4836892A (en) * 1986-10-09 1989-06-06 Union Camp Corporation Pulp blends for linerboards
US5022962A (en) * 1988-10-25 1991-06-11 Enso-Gutzeit Oy Method for the treatment of spent liquors in pulp production
US6627041B2 (en) 2000-03-06 2003-09-30 Georgia-Pacific Corporation Method of bleaching and providing papermaking fibers with durable curl
US6899790B2 (en) 2000-03-06 2005-05-31 Georgia-Pacific Corporation Method of providing papermaking fibers with durable curl
EP1001076B1 (fr) * 1998-11-16 2006-04-26 Sicem Saga Spa Procédé et installation de production de pâtes à papier
US20070277947A1 (en) * 2006-06-02 2007-12-06 Xuan Truong Nguyen Process for manufacturing pulp, paper and paperboard products
CN107429484A (zh) * 2015-03-11 2017-12-01 安德里兹有限公司 用于木质纤维素材料的制浆的方法和系统
US11441271B2 (en) * 2018-02-05 2022-09-13 Domtar Paper Company Llc Paper products and pulps with surface enhanced pulp fibers and increased absorbency, and methods of making same
US12104327B2 (en) 2019-09-23 2024-10-01 Domtar Paper Company, Llc Tissues and paper towels incorporating surface enhanced pulp fibers and methods of making the same
US12116732B2 (en) 2019-09-23 2024-10-15 Domtar Paper Company, Llc Paper products incorporating surface enhanced pulp fibers and having decoupled wet and dry strengths and methods of making the same

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1372640A (en) * 1919-11-17 1921-03-22 Flintkote Co Paper felt
US1847326A (en) * 1928-01-28 1932-03-01 Lewis L Alsted Paper pulp and process of making same
US2660097A (en) * 1949-04-16 1953-11-24 Price Brothers & Company Ltd Method of processing wood pulp
US3202569A (en) * 1961-06-22 1965-08-24 Johns Manville Cold caustic fiberboard manufacture
US3811995A (en) * 1972-09-05 1974-05-21 Westvaco Corp Method of high yield semichemical pulp production
US3827934A (en) * 1971-06-28 1974-08-06 Westvaco Corp Process for producing high strength,high yield hardwood pulp

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1372640A (en) * 1919-11-17 1921-03-22 Flintkote Co Paper felt
US1847326A (en) * 1928-01-28 1932-03-01 Lewis L Alsted Paper pulp and process of making same
US2660097A (en) * 1949-04-16 1953-11-24 Price Brothers & Company Ltd Method of processing wood pulp
US3202569A (en) * 1961-06-22 1965-08-24 Johns Manville Cold caustic fiberboard manufacture
US3827934A (en) * 1971-06-28 1974-08-06 Westvaco Corp Process for producing high strength,high yield hardwood pulp
US3811995A (en) * 1972-09-05 1974-05-21 Westvaco Corp Method of high yield semichemical pulp production

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4060450A (en) * 1972-09-01 1977-11-29 Westinghouse Electric Corporation High yield saturating paper
US4294653A (en) * 1974-09-23 1981-10-13 Mo Och Domsjo Aktiebolag Process for manufacturing chemimechanical cellulose pulp in a high yield within the range from 65 to 95%
US4145246A (en) * 1976-07-19 1979-03-20 Crown Zellerbach Corporation Process for making high-strength, high-yield sulfite-modified thermomechanical pulp and a linerboard composition produced therefrom
US4836892A (en) * 1986-10-09 1989-06-06 Union Camp Corporation Pulp blends for linerboards
US5022962A (en) * 1988-10-25 1991-06-11 Enso-Gutzeit Oy Method for the treatment of spent liquors in pulp production
EP1001076B1 (fr) * 1998-11-16 2006-04-26 Sicem Saga Spa Procédé et installation de production de pâtes à papier
US7291247B2 (en) 2000-03-06 2007-11-06 Georgia-Pacific Consumer Operations Llc Absorbent sheet made with papermaking fibers with durable curl
US6899790B2 (en) 2000-03-06 2005-05-31 Georgia-Pacific Corporation Method of providing papermaking fibers with durable curl
US20050145348A1 (en) * 2000-03-06 2005-07-07 Lee Jeffrey A. Method of providing paper-making fibers with durable curl and absorbent products incorporating same
US20040016524A1 (en) * 2000-03-06 2004-01-29 Lee Jeffrey A. Method of bleaching and providing papermaking fibers with durable curl
US6627041B2 (en) 2000-03-06 2003-09-30 Georgia-Pacific Corporation Method of bleaching and providing papermaking fibers with durable curl
US8277606B2 (en) 2000-03-06 2012-10-02 Georgia-Pacific Consumer Products Lp Method of providing paper-making fibers with durable curl and absorbent products incorporating same
US20070277947A1 (en) * 2006-06-02 2007-12-06 Xuan Truong Nguyen Process for manufacturing pulp, paper and paperboard products
US20090145562A1 (en) * 2006-06-02 2009-06-11 Xuan Truong Nguyen Process for manufacturing pulp, paper and paperboard products
US7967948B2 (en) 2006-06-02 2011-06-28 International Paper Company Process for non-chlorine oxidative bleaching of mechanical pulp in the presence of optical brightening agents
CN107429484A (zh) * 2015-03-11 2017-12-01 安德里兹有限公司 用于木质纤维素材料的制浆的方法和系统
US10724174B2 (en) 2015-03-11 2020-07-28 Andritz Inc. Processes and systems for the pulping of lignocellulosic materials
US11352746B2 (en) 2015-03-11 2022-06-07 Andritz Inc. Processes and systems for the pulping of lignocellulosic materials
US11441271B2 (en) * 2018-02-05 2022-09-13 Domtar Paper Company Llc Paper products and pulps with surface enhanced pulp fibers and increased absorbency, and methods of making same
US20220412006A1 (en) * 2018-02-05 2022-12-29 Domtar Paper Company,Llc Paper products and pulps with surface enhanced pulp fibers and increased absorbency, and methods of making same
US12104324B2 (en) * 2018-02-05 2024-10-01 Domtar Paper Company, Llc Paper products and pulps with surface enhanced pulp fibers and increased absorbency, and methods of making same
US12104327B2 (en) 2019-09-23 2024-10-01 Domtar Paper Company, Llc Tissues and paper towels incorporating surface enhanced pulp fibers and methods of making the same
US12116732B2 (en) 2019-09-23 2024-10-15 Domtar Paper Company, Llc Paper products incorporating surface enhanced pulp fibers and having decoupled wet and dry strengths and methods of making the same

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Publication number Publication date
FI750031A (xx) 1975-10-02
JPS50126901A (xx) 1975-10-06
CA1051151A (en) 1979-03-27
JPS5313001B2 (xx) 1978-05-06
SE7500167L (xx) 1975-10-02

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Owner name: SPROUT-BAUER, INC.,

Free format text: MERGER;ASSIGNOR:SWM CORPORATION, MERGED INTO BAUER BROS. CO. CHANGED TO;REEL/FRAME:004810/0977

Effective date: 19871029