US3849247A - Screening and feeding device for cellulose digesters - Google Patents

Screening and feeding device for cellulose digesters Download PDF

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Publication number
US3849247A
US3849247A US00339758A US33975873A US3849247A US 3849247 A US3849247 A US 3849247A US 00339758 A US00339758 A US 00339758A US 33975873 A US33975873 A US 33975873A US 3849247 A US3849247 A US 3849247A
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Prior art keywords
chips
vessel
outlets
digester
shell
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Expired - Lifetime
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US00339758A
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English (en)
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J Richter
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Metso Fiber Karlstad AB
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Kamyr AB
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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
    • D21C7/00—Digesters
    • D21C7/06—Feeding devices

Definitions

  • ABSTRACT Foreign Application Priority Data A cellulose digesting apparatus having at least one Mar. 21, 1972 Sweden 72/3600 vertical digester in open communication with a pressure-resistantvessel containing a screening device, the [52] US. Cl 162/237, 159/23, 162/52, screening device comprising a shell having an upper 162/241, 162/246, 210/415, 214/ 17 C impervious portion and a lower strainer portion, [51] Int. Cl.
  • D2lc 7/06 wherein liquid is strained from a chips-liquid suspen-
  • Field of Search 162/246, 241, 242, 237, sion for recirculation of the liquid, and a feeding de- 162/52, 17; 214/17 C; 259/23, 8; 210/413, vice which is adapted to transfer the chips from said 414, 415; 100/117 vessel to the digester, around the shell a circular trough for collecting chips discharged over the top
  • References Cited edge of the impervious portion, the feeding device UNITED STATES PATENTS comprising a plurality of chips outlets in the vessel each adapted for connection to a separate digester 31323111; 11132?
  • the invention relates to cellulose digesting apparatus for the charging of chips to a digester which is in open communication with a separate pressure-resistant vessel containing a screening device which strains a chips-liquid-suspension in order to recycle the liquid, and a feeding device for the transfer of the chips from said vessel to the digester.
  • a digester is shown in the U.S. Pat. No. 3,429,773.
  • the invention is concerned with the problem that cellulose mills often are in continuous expansion, and therefore, after only a few years production, a new digesting plant may have to be increased in capacity.
  • An object of the invention is to effect in a simple manner and at a comparatively small cost, a desired expansion so that cellulose digesting plants can be expanded with the greatest possible use of the equipment already installed, i.e. with as little rebuilding thereof as possible.
  • the invention is directed at using the installed devices for pretreatment of the chips and transportation thereof to the digester top; if at a later stage it is desired to enlarge the digesting plant with one or more further digesters, only simple modifications need be made.
  • a pressureresistant vessel with a plurality of chips outlets, each adapted for connection to a separate digester, allowing the plant to be supplemented with one or more additional digesters.
  • a device is provided for the proper distribution of the chips into the outlets employed.
  • the upper end of a vertical cylindrical separating shell surrounds a feeder screw coaxial therewith, and feeds the chips upwardly.
  • This upper end is surrounded by a portion of the pressure vessel preferably forming a circular trough with downwardly sloping chips outlet tubes being connected to the bottom of said trough at a level lower than the upper edge of said separating shell, so that chips flowing over said edge are transferred to the digester or digesters substantially by the action of gravity.
  • FIG. 1 diagrammatically shows a cellulose digesting apparatus comprising two digesters
  • FIG. 2 is a vertical elevational and partially crosssectional view shown at an enlarged scale, of the screening and chips distributing vessel forming part of said apparatus;
  • FIG. 3 is a modified form of the invention shown in FIGS. 1 and 2
  • FIG. 4 is a partial cross-sectional view taken along lines 4-4 of FIG. 2, with chips removed, showing exemplary displaceable lids for varying the size of the chips outlets.
  • the apparatus in FIG. 1 comprises two vertical essentially cylindrical continuous digesters 11, 13, the upper ends of which are continuously fed with a mixture of chips and digesting liquor. From the lower ends of the digesters l1, l3 digested and partially washed cellu- The chips are pretreated and distributed to each of the digesters. Chips from chips bin are fed in the usual manner through a low-pressure valve 17 into a steaming vessel 19 wherein the chips are steamed with low-pressure steam. By means of a high-pressure transfer valve 21 the chips are then transferred'to a conduit 23 filled with the digesting liquor at approximately the digester pressure. The conduit 23 is connected to a vertical, conical impregnating vessel 25 whose circumference increases with its vertical longitudinal axis.
  • the vessel 25 is united with the pressure-resistant vessel 27 which encloses a screening device and a chips distributing device. Liquid screened off by said screening device in vessel 27 is returned through the conduit 29 to the high-pressure transfer valve 21. Pump 31 circulates the liquid in a loop over 21, 23, 25,27, and 29. In said loop the chips are introduced by means of the valve 21 so that the chips suspended in the liquid are flushed into the vessel 27 situated at the level of the digester tops and are delivered and retained therein, whereas the liquid of the suspension is separated and recirculated.
  • the vessel 27, shown partially in sections in FIG. 2, is provided within a pressure-resistant casing 33 and a vertical cylindrical separating shell 35 of the same diameter as and forming an extension of the upper end of the impregnating vessel 25.
  • the lower end of the separating shell 35 is perforated or shaped with slits'so as to form a strainer, whereas the uppermost portion of the separating shell is impervious and forms a partition.
  • Inserted into the shell is a feeder screw 37 attached to a vertical shaft 39 which extends through and is sealed to the lid 41 of the casing 33.
  • a motor 42 (FIG. 1) connected to the exterior end of the shaft 39 turns the feeder screw 37 causing the chips-liquor-suspension to move-upwardly within the separating shell 35.
  • Vessel 27 forms a steam-filled space, surrounding the upper edge 43 of the separating shell, the lower boundary of which forms a circular launder or trough 47.
  • Said trough 47 extends around the upper edge 43 of the separating shell 35 and has its bottom situated at a lower level than said edge, so that chips fed upwardly through the shell by means of the feeder screw 37, drop over the edge 43 down into the trough 47 by gravity.
  • Connected to the bottom of the trough are at least two downwardly sloping chips outlet tubes 49, 51, which by means of connecting tubes 53 and 55 may be connected to the separating digesters l1 and 13.
  • Said tubes form an open communication between the vessel 27 and the respective operating digester, but it may be advantageous to insert shut-off valves in the conduits 53, 55 in order to be able to operate one digester without interruption when the other is temporarily taken out of operation.
  • the vessel 27 is provided with a device for distributing the chips upon the chips outlets 49, 51.
  • said distributing device consists of a scraper attached to the shaft 39 which comprises scraper arms 57 projecting radially across the edge of the shell 35 and down into the bottom of the trough 47. Chips that drop over the edge 43 down into the trough 47 are collected by said rotary scraper arms and are carrying along until they drop into the chips outlet tubes 49, 51. With diametrically opposite locations of two outlets the chips will be distributed into equal parts into each outlet.
  • the digesters are of different sizes or capacities so that distribution of the chips may be required in different proportions, the location of the outlets on the periphery may be changed accordingly.
  • the outlets are placed at an angle of 120 degrees from each other, whereby the scrapers collect and transfer to the smaller digester the chips which have dropped into one third of the circumference of the trough, and collect and transfer to the larger digester chips which have dropped into the remaining two thirds of the circumference of the trough.
  • the desired distribution may also be attained by varying the size of the outlets. Variations of both size and angle can be brought about by displaeeable lids, such as lids 50 shown in FIG. 4, in the bottom of the trough 47.
  • the drawings refer to an apparatus comprising two digesters, but the apparatus may be operated with a single digester, as is shown in FIG. 2 by the digester 13 with dash lines.
  • the chips outlet 51 is blocked, eg by means of a blind flange at its lower end, and the scraper arms 57 are not used for their distributing function but merely for moving the chips in the trough to the single outlet 49.
  • the number of chips outlets may be increased and it is possible to use a distributing vessel with three, four or more chips outlets that are used according to the total required output of the digesting apparatus.
  • the entire quantity of digesting liquor required for the digestion is supplied through the conduit 61 and high-pressure pump 63 after having been mixed with the liquor transferred to the low-pressure side of the transfer valve 2i, which is returned via the screening device 65 and the tank 67.
  • a portion of the liquor supplied is transferred into the conduit 29 by the valve 69 which is controlled by the level 45 in the vessel 27 so as to maintain said level, whereas the remaining portion of the liquor supplied is pumped through the conduit '71 directly to the digester tops and distributed by means of the valves 73, and 75.
  • said liquor portion is introduced into the conduits 77 and 79 along with pressure steam to the digesters for heating the chips therein to digesting temperature. In this manner the liquor will be atomized and sprayed as a mist over the chips in the digester tops.
  • all digesting liquor may be supplied to the vessel 27. This is preferred when the chips are able to absorb a sufficient quantity of liquor, so that a free liquor level 45 will be maintained below the edge of the straining portion of shell 35 without requiring any particular level control. On the other hand, if the liquor is to flow over that edge 43, procedures should be taken to distribute the liquor properly into the digesters.
  • the apparatus can also be operated when the digesting liquor or the main part thereof is supplied directly to the digesters and such liquid as is required for suspending the chips and flushing them to the digester tops consists of water, as is the case in prehydrolysis digesters, or of more or less diluted white liquor or black liquor.
  • the inlet to the bottom of the vessel 27 has been modified by the addition of a chamber 26 and secondary scraper 28.
  • the section 26 effectively increases the total volume of pipe 25 thereby providing for a longer retention time of the chips in the feeding line; that is, chips are impregnated in liquid at full digester pressure.
  • the chamber 26 may be a conical pipe connection and 28 is a rotating scraper body which will facilitate the chip movement from the larger pipe to the smaller diameter entrance 38.
  • the scraper rotates together with screw 37.
  • the cone can be omitted and the scraper 28 substituted by coupling the screw 37 to the scraper shaft.
  • the scraper itself can be supported by the bearings in the bearing housing which in turn is supported by arms fastened to pipe connection 26.
  • a cellulose digesting apparatus in which a top portion of at least one vertical digester is in open communication with a pressure-resistant vessel containing a screening device wherein liquid is strained from a chips-liquid suspension for recirculation of the liquid, and a feeding device for transferring the chips from said vessel to the digester, said feeding device comprising a plurality of chips outlets in the vessel each for connection to a separate digester and a distributing device for the distribution of the chips upon the outlets used, said screening device comprising a separating shell having an upper impervious portion and a lower strainer portion including means for collecting liquid separated from the chips; means for feeding the strainer chips upwardly through the shell for discharge over the top edge of the upper impervious portion, said means including a feeder screw surrounded by said shell and coaxial therewith; collecting means around said shell and below the top edge of said impervious portion for collecting strained chips discharged therefrom, said collecting means comprising a circular trough; the chips outlets comprising tubes connected to and sloping downwardly from the bottom of
  • Apparatus according to claim 1 wherein the distributing device comprises one or more scraper arms extending radially beyond the separating shell into the circular trough and being attached to and driven with the feeder screw.
  • Apparatus according to claim 1 further comprising means for varying the size of the chips outlets to effect a desired distribution of chips to chips outlets.

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US00339758A 1972-03-21 1973-03-12 Screening and feeding device for cellulose digesters Expired - Lifetime US3849247A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE03600/72A SE354302B (zh) 1972-03-21 1972-03-21

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US (1) US3849247A (zh)
JP (1) JPS5424001B2 (zh)
BR (1) BR7301978D0 (zh)
CA (1) CA981495A (zh)
DE (1) DE2312679C3 (zh)
FI (1) FI51507C (zh)
FR (1) FR2176981B1 (zh)
NO (1) NO136208C (zh)
SE (1) SE354302B (zh)
ZA (1) ZA731562B (zh)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3950147A (en) * 1974-08-08 1976-04-13 Kamyr, Inc. Process for feeding coal to a fluidized bed or suspended particle pressurized processing chamber and apparatus for carrying out the same
US4125384A (en) * 1977-03-03 1978-11-14 Kamyr Inc. Method and apparatus for continuously feeding solid particles into a pressurized container
US4347134A (en) * 1981-09-03 1982-08-31 Svehaug Oswald C Slurry separator having reaction nozzle driven rotory blades wiping a conical filter
US5213662A (en) * 1991-08-14 1993-05-25 Kamyr, Inc. Treatment of chips with high temperature black liquor to reduce black liquor viscosity
US5300195A (en) * 1988-05-31 1994-04-05 Kamyr Ab Continuous vertical digester apparatus
US5413677A (en) * 1993-04-05 1995-05-09 Kamyr, Inc. Method for producing chemical pulp from hardwood chips
US5795438A (en) * 1996-11-04 1998-08-18 Ahlstrom Machinery Inc. Method and apparatus for feeding multiple digesters
US20020129911A1 (en) * 2000-10-16 2002-09-19 Marcoccia Bruno S. Process and configuration for providing external upflow/internal downflow in a continuous digester
US20030121624A1 (en) * 2000-07-13 2003-07-03 Voith Paper Patent Gmbh Process and device for loading fibers with calcium carbonate
US20030175943A1 (en) * 1998-05-25 2003-09-18 Chisso Corporation Intermediates and improved processes for the preparation of neplanocin A
US7951127B2 (en) 2006-12-15 2011-05-31 Kimberly-Clark Worldwide, Inc. Composite bodyside liner
WO2012060749A1 (en) * 2010-11-03 2012-05-10 Metso Paper Sweden Ab Top separator for steam/liquid digester
US20210355604A1 (en) * 2020-05-12 2021-11-18 Seiko Epson Corporation Screw feeder and fiber structure manufacturing apparatus

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5151939A (ja) * 1974-10-31 1976-05-07 Canon Kk Saisenpataanyohotorejisutogenzoeki
SE7802408L (sv) * 1978-03-02 1979-09-03 Gloeersen Stig Sett for att overfora med vetska transporterbara material sasom fibermaterial
US6254701B1 (en) 1996-03-14 2001-07-03 Taiho Kogyo Co., Ltd. Copper alloy and sliding bearing having improved seizure resistance
US6120646A (en) * 1998-04-06 2000-09-19 Kvaerner Pulping Ab Feeding system of feeding a cellulose material

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2459180A (en) * 1943-12-04 1949-01-18 Kamyr Ab Apparatus for charging fibrous material into a digester
US2969113A (en) * 1957-12-18 1961-01-24 Sprout Waldron & Co Inc Pulp manufacture
US3041232A (en) * 1957-02-06 1962-06-26 Kamyr Ab Method of continuous cellulose digestion and digester apparatus for practicing said method
US3294626A (en) * 1963-07-15 1966-12-27 William R Matthews Continuous flow wafer impregnator and digest tube
US3467573A (en) * 1965-12-13 1969-09-16 Improved Machinery Inc Upflow digester containing means for separate removal of wash liquor and pulping liquor and method of pulping in said digester
US3471366A (en) * 1963-01-08 1969-10-07 Defibrator Ab Apparatus for use in the production of pulp from lignocellulose containing material
US3586600A (en) * 1967-07-27 1971-06-22 Improved Machinery Inc Continuous digesting apparatus
US3681192A (en) * 1968-07-04 1972-08-01 Defibrator Ab Sluice feeders for introducing finely divided chips into vessels under pressure
US3743572A (en) * 1970-06-11 1973-07-03 Kamyr Ab Screw feeder in a continuous cellulose digester

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2459180A (en) * 1943-12-04 1949-01-18 Kamyr Ab Apparatus for charging fibrous material into a digester
US3041232A (en) * 1957-02-06 1962-06-26 Kamyr Ab Method of continuous cellulose digestion and digester apparatus for practicing said method
US2969113A (en) * 1957-12-18 1961-01-24 Sprout Waldron & Co Inc Pulp manufacture
US3471366A (en) * 1963-01-08 1969-10-07 Defibrator Ab Apparatus for use in the production of pulp from lignocellulose containing material
US3294626A (en) * 1963-07-15 1966-12-27 William R Matthews Continuous flow wafer impregnator and digest tube
US3467573A (en) * 1965-12-13 1969-09-16 Improved Machinery Inc Upflow digester containing means for separate removal of wash liquor and pulping liquor and method of pulping in said digester
US3586600A (en) * 1967-07-27 1971-06-22 Improved Machinery Inc Continuous digesting apparatus
US3681192A (en) * 1968-07-04 1972-08-01 Defibrator Ab Sluice feeders for introducing finely divided chips into vessels under pressure
US3743572A (en) * 1970-06-11 1973-07-03 Kamyr Ab Screw feeder in a continuous cellulose digester

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3950147A (en) * 1974-08-08 1976-04-13 Kamyr, Inc. Process for feeding coal to a fluidized bed or suspended particle pressurized processing chamber and apparatus for carrying out the same
US4125384A (en) * 1977-03-03 1978-11-14 Kamyr Inc. Method and apparatus for continuously feeding solid particles into a pressurized container
US4347134A (en) * 1981-09-03 1982-08-31 Svehaug Oswald C Slurry separator having reaction nozzle driven rotory blades wiping a conical filter
US5300195A (en) * 1988-05-31 1994-04-05 Kamyr Ab Continuous vertical digester apparatus
US5213662A (en) * 1991-08-14 1993-05-25 Kamyr, Inc. Treatment of chips with high temperature black liquor to reduce black liquor viscosity
US5413677A (en) * 1993-04-05 1995-05-09 Kamyr, Inc. Method for producing chemical pulp from hardwood chips
US5795438A (en) * 1996-11-04 1998-08-18 Ahlstrom Machinery Inc. Method and apparatus for feeding multiple digesters
US20030175943A1 (en) * 1998-05-25 2003-09-18 Chisso Corporation Intermediates and improved processes for the preparation of neplanocin A
US20030121624A1 (en) * 2000-07-13 2003-07-03 Voith Paper Patent Gmbh Process and device for loading fibers with calcium carbonate
US6599390B2 (en) * 2000-07-13 2003-07-29 Voith Paper Patent Gmbh Process for loading fibers with calcium carbonate in a plurality of reactors
US6755941B2 (en) * 2000-07-13 2004-06-29 Voith Paper Patent Gmbh Apparatus for loading fibers with calcium carbonate
US6881298B2 (en) 2000-07-13 2005-04-19 Voith Paper Patent Gmbh Process for loading fibers with calcium carbonate in a plurality of reactors
US20020129911A1 (en) * 2000-10-16 2002-09-19 Marcoccia Bruno S. Process and configuration for providing external upflow/internal downflow in a continuous digester
US7951127B2 (en) 2006-12-15 2011-05-31 Kimberly-Clark Worldwide, Inc. Composite bodyside liner
WO2012060749A1 (en) * 2010-11-03 2012-05-10 Metso Paper Sweden Ab Top separator for steam/liquid digester
US20210355604A1 (en) * 2020-05-12 2021-11-18 Seiko Epson Corporation Screw feeder and fiber structure manufacturing apparatus
US11891722B2 (en) * 2020-05-12 2024-02-06 Seiko Epson Corporation Screw feeder and fiber structure manufacturing apparatus

Also Published As

Publication number Publication date
DE2312679C3 (de) 1975-11-13
JPS496202A (zh) 1974-01-19
NO136208B (zh) 1977-04-25
DE2312679B2 (de) 1975-01-02
FR2176981B1 (zh) 1976-09-10
CA981495A (en) 1976-01-13
DE2312679A1 (de) 1973-10-04
FI51507C (fi) 1977-01-10
JPS5424001B2 (zh) 1979-08-17
NO136208C (no) 1977-08-03
ZA731562B (en) 1973-11-28
FI51507B (zh) 1976-09-30
FR2176981A1 (zh) 1973-11-02
BR7301978D0 (pt) 1974-07-18
SE354302B (zh) 1973-03-05

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