US3622262A - Method for washing preferentially cellulosic pulp - Google Patents

Method for washing preferentially cellulosic pulp Download PDF

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Publication number
US3622262A
US3622262A US720717A US3622262DA US3622262A US 3622262 A US3622262 A US 3622262A US 720717 A US720717 A US 720717A US 3622262D A US3622262D A US 3622262DA US 3622262 A US3622262 A US 3622262A
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United States
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liquid
washing
sieve
cellulosic pulp
treatment
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Expired - Lifetime
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US720717A
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English (en)
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Nils Gustav Leffler
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Valmet AB
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Sunds 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
    • 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

Definitions

  • the invention includes both a special process and a special arrangement, by which it is possible to keep stationary sieve surfaces free from clogging matter.
  • the new process is meant for the treatment, by means of a liquid, such as water for washing (but also in connection with the displacement of liquor and dewatering) of a fibrous material suspended in aliquid and being fed through a preferentially vertical and preferably cylindrical container in the axial direction thereof, said treatment being carried out in that part of the container which is filled with the material, the treatment liquid being caused to flow through the suspension of material from at least one means of supply for the treatment liquid towards at least one collecting chamber for withdrawn liquid, said chamber having a foraminous, preferably perforate wall.
  • the new process is characterized substantially in that the influx of the withdrawn liquid into the collecting chamber, is, entirely or partly, interrupted at suitable intervals in order to prevent clogging of the perforate wall of the collecting chamber and/or to facilitate the movement of the material past or along said surface. It is thought that this effect will be obtained thereby that the pulsatory flow will, inter alia, prevent fibers from getting stuck in the sieve holes, thus increasing the frictional resistance, and/or creating a film of liquid on the sieve surfaces in order to make it easier for the cellulosic pulp to slide past the same.
  • Such film of liquid may also be obtained by spraying liquid along that sieve surface which is turned against the pulp and causing such spraying to take place in the same direction as the direction of feed of the pulp from one or more slots, located one after the other in the axial direction of the container all the way around along the sieve surface.
  • An effective and correctly adjusted rinsing may result therein that the liquid in the collecting chamber inside the sieve plate member need not be pulsated, in which case the members serving that purpose may be dispensed with.
  • the pressure variations are obtained through the intermediary of liquid, which by means of a vibrator or some other means, producing pulsations in the liquid, is pulsated within at least one conduit communicating with the collecting chamber. The pulsation of the liquid within the collecting chamber may be caused to take place either continuously or intermittently.
  • the liquid in the collecting chamber there may be imparted, at suitable intervals, one or more pressure surges and/or slower pressure rises.
  • the liquid should have a resultant flow into the collecting chamber for withdrawn liquid (the sieve device).
  • An apparatus for carrying out the new method comprises a, preferentially, vertical and preferably cylindrical container, adapted for axial feed therethrough of the material to be treated, at least one means of supply for treatment liquid located within said container and below the intended level of material therein and furthennore at least one collecting chamber for withdrawn liquid arranged in a corresponding way but displaced in the radial direction of the container.
  • the apparatus is substantially characterized in that to the collecting chambers for withdrawn liquid there is connected at least one member for transmitting pressure impulses to the liquid in said collecting chambers from means serving for generating pressure variations.
  • FIG. 1 is a vertical sectional view of part of the apparatus, when mounted in a vertical container for the treatment of fibrous material
  • FIG. 2 on a larger scale, illustrating a longitudinal sectional view of the means for pulsating the treatment liquid.
  • FIG. 3 is a sectional view on the line IIIIII of FIG. 1 and FIG. 4, finally, a vertical sectional view of the collecting chamber.
  • Reference numeral 1 indicates part of the upper portion of a vertical, preferably cylindrical container, arranged to be traversed continuously by material to be treated, preferentially cellulosic pulp 2, in the direction indicated by capital A arrows.
  • the treatment (washing) liquid is indicated by 3
  • 4 is tower scraping means, of a known kind, rigidly mounted on a rotary shaft 5.
  • 6, 7 and 8 are supply means for washing liquid and said means may be stationarily and/or rotatably mounted. Also, they may be embodied in a known manner, for instance as substantially vertically extending spray pipes or nozzles, which are movable along paths concentric with annular collecting chambers for withdrawn liquid in accordance with the disclosure of Swedish Pat. Specification 198,496.
  • FIGS. 9 and 10 indicate collecting chambers for withdrawn liquid, said chambers preferably being devised as sieve baskets.
  • One or more pipes 11 communicate with the collecting chambers 9' and 10, said pipes serving for leading away the withdrawn liquid by way of an overflow 12.
  • H indicates the height of the static pressure determining the speed of How of the liquid through the pipe 11.
  • one (or more) pipe 13 communicates with the collecting chambers 9 and 10, said pipe 13 being, at its one end, by way of a funnellike portion 14 connected to means 15 for generating pressure variations (a vibrator or a pulsator), which through the intermediary of that liquid which normally is to be present in the pipe 13 and in the funnellike portion 14, are to produce a pulsatory flow of liquid through the slots or openings 16 in the walls of the chambers 9 and 10.
  • the vibrator 15 comprises two centrifugal weights 18, adapted to rotate in opposite directions via gear drives 17.
  • the vibrator is adapted to actuate a membrane 20, clamped between flanges 19, said membrane, by way of the liquid in the pipe l3, l4, transmitting the movements emanating from the vibrator, so that the previously mentioned, pulsatory flow through the slots 16 is obtained.
  • the pipe 13 directs the pulsatory flow towards the sieve baskets 9, l0 and not towards the outlet pipe 11.
  • Such other means may consist of, for instance, a piston reciprocating in a housing.
  • the piston may be driven continuously or intermittently and its movements may be rapid or slow, even very slow.
  • the use of a piston has proved particularly suitable for slow movements and long lengths of stroke or in case a rapid pressure surge is desired for the purpose of cleansing the slots or holes during the movement of the piston in one direction and in case a uniform and smooth withdrawal is desired during the return of the piston in the opposite direction. Consequently, in connection with this last-mentioned functioning the piston is to move rapidly in one direction and then to return slowly in the other direction.
  • the liquid within the housing of the piston may either be in a direct, open connection with the collecting chambers 9, or in a power transmitting connection by way of a membrane or the like. After one single stroke, i.e.
  • 21 and 22 indicate supply conduits for washing liquid to the chamber 8 and, respectively, to the chambers 6 and 7.
  • said supply conduits are connected to a water conduit or to some other conduit, possibly also to a backwater conduit, i.e. in such a manner that the amount of liquid and the pressure may be controlled.
  • the conduit 2] ends above the arms of the tower scraping means 4. Treated material (washed pulp) leaves through the outlet 23.
  • the pressure p be greater than the sum of the pressure p, and the difference in static pressure between the levels p, and p, at friction-free flow. If the difierence between these pressures is great the flow B of the displacement liquid may give larger inflow volumes at the lower portions of the sieve baskets (the collecting chambers) 9, 10 than at the upper portions.
  • the collecting chamber 9 is meant to have four outlet pipes, uniformly distributed along the circumference. All these pipes (with pipes between the collecting chambers) are indicated by Ill.
  • the collecting chamber 10 is meant to have two connections to pipes 11, counting along its circumference. The number of collecting pipes may be larger or smaller. A collecting chamber having a large diameter should have more pipes 11 than a chamber having a smaller diameter. Such pipes also may extend out of the tower, completely separated from each other. Theoretically, the pitch around the collecting chambers should be equal, irrespective of the diameters of the chambers. The same thing applies to the inlet pipes of the chambers 6, 7 for supplying the washing liquid.
  • the liquid should not have to be given a pulsatory motion, since the flow of liquid proceeds in a direction out of the chambers and the fibers of the cellulosic pulp should not have any tendency to cause clogging of slots or holes.
  • it may, under certain circumstances, be of advantage to supply the chambers with intermittent pressure surges through the liquid in the supply pipe (pipes) and, under particularly difficult conditions, with continuous pressure surges.
  • the invention may, with advantage, be used also in such apparatus in which cellulosic pulp is dewatered from 1-5 percent to about 8-15 percent in vertical containers with concentric sieve baskets arranged, in principle, in the way shown in FIG. 1.
  • Such sieve baskets may be provided at the top, at the middle or at the bottom portion of the container.
  • the dewaterin g may be followed by dilution to, for instance, l-5 percent, and repeated dewatering to about 8-15 percent by means of two successive sets of sieve baskets, when counting in the direction of flow of the cellulosic pulp.
  • the supplying of liquid may then take place by rotatable spray pipes in a known manner in accordance with the previously mentioned Swedish Pat. No. l98,496.
  • the sieve holes may be kept clean by pressure surges with clean water, white water or some other suitable liquid.
  • a further object of the invention is that it should be possible to move the cellulosic pulp from one container to another (for instance, from one bleaching tower to a successive bleaching tower) without other dilution takintg place than the one which might be obtained from a liqut treatment agent of the bleaching agent type, the condensate type et cetera.
  • the feeding of the cellulosic pulp may take place intermittently or shockwise, in which case no, or a limited, washing takes place during the feeding of the cellulosic pulp (in the direction of the arrow A).
  • the sieve members (the collecting chambers) 9, 10 may be given a vibratory motion in the axial and/or radial direction of the container 1, by which the liquid need not be pulsated by means of the special means described above.
  • the sieve surfaces (i.e. the foraminous parts) of the sieve members may be parallel to the direction of flow of the cellulosic pulp, as shown in FIGS. 1, 3 and 4, or they may form an angle, to said direction.
  • the method and/or the apparatus according to the invention is particularly suitable for the treatment-by means of a liquid-of suspensions of fibers or materials within the range of concentration of 1-15 percent.
  • a method for the continuous treatment of a suspension of a fibrous material comprising introducing the suspension into one end of a substantially vertical container, moving the suspension axially through the container, said container being, in the part where the treatment is carried out, filled with the suspension, introducing a treatment liquid into the moving suspension at a plurality of points located, with respect to each other, both axially and transversely of the container, passing the treatment liquid in a direction forming an angle with the direction of movement of the suspension, withdrawing liquid from the suspension at a plurality of points located, with respect to each other, both axially and transversely of the container, the points of withdrawal of liquid being arranged stationan'ly and spaced from the points of introduction of the treatment liquid transversely of the container, the space between the points of introduction and withdrawal being filled with the suspension of fibrous material, combining the liquid withdrawn at the plurality of points of withdrawal, passing the withdrawn liquid out of the container, periodically interrupting, entirely or partly, the flow of liquid at the points of withdrawal thereof from the suspension so that any
  • a method as claimed in claim I wherein the step of periodically interrupting the flow of liquid at the points of withdrawal from the suspension comprises subjecting the liquid to pressure impulses.

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)
  • Sampling And Sample Adjustment (AREA)
US720717A 1967-04-13 1968-04-11 Method for washing preferentially cellulosic pulp Expired - Lifetime US3622262A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE6705183A SE324950C (sv) 1967-04-13 1967-04-13 Forfarande och anordning for vetskebehandling foretredesvis tvettning av fibersuspensioner av cellulosamassa

Publications (1)

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US3622262A true US3622262A (en) 1971-11-23

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US720717A Expired - Lifetime US3622262A (en) 1967-04-13 1968-04-11 Method for washing preferentially cellulosic pulp
US00125349A Expired - Lifetime US3729961A (en) 1967-04-13 1971-03-17 Apparatus for the washing of preferably cellulosic pulp

Family Applications After (1)

Application Number Title Priority Date Filing Date
US00125349A Expired - Lifetime US3729961A (en) 1967-04-13 1971-03-17 Apparatus for the washing of preferably cellulosic pulp

Country Status (7)

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US (2) US3622262A (enrdf_load_stackoverflow)
DE (1) DE1761175C3 (enrdf_load_stackoverflow)
FI (1) FI53992C (enrdf_load_stackoverflow)
FR (1) FR1560832A (enrdf_load_stackoverflow)
GB (1) GB1205292A (enrdf_load_stackoverflow)
NO (1) NO132697C (enrdf_load_stackoverflow)
SE (1) SE324950C (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3905766A (en) * 1968-09-18 1975-09-16 Sunds Ab Method for the liquid treatment of, primarily, cellulosic pulp
US4975148A (en) * 1988-12-06 1990-12-04 Ahlstromforetagen Svenska Ab Cold blow system for batch production of pulp
US5027620A (en) * 1990-02-26 1991-07-02 Kamyr Ab Diffuser with flexible bellows and internal actuator
CN110656529A (zh) * 2019-09-12 2020-01-07 中国制浆造纸研究院有限公司 一种微细纤维及其制备方法和应用以及一种电气设备所用隔膜的制备方法

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE386692B (sv) * 1974-03-14 1976-08-16 Sunds Ab Anordning for koncentrering och/eller vetskebehandling sasom tvettning eller blekning av vetskehaltiga emnesblandningar, serskilt cellulosamassa
SE415202B (sv) * 1976-12-06 1980-09-15 Sunds Ab Anordning for koncentrering och/eller vetskebehandling av vetskehaltiga emnesblandningar
US4529482A (en) * 1979-04-25 1985-07-16 Kamyr Aktiebolag Apparatus for the treatment of pulp having oscillating distributing wiper blades
US4881286A (en) * 1987-11-27 1989-11-21 Kamyr Ab Effective diffuser/thickener screen backflushing
US4793161A (en) * 1987-11-27 1988-12-27 Kamyr Ab Effective diffuser/thickener screen backflushing
US5129119A (en) * 1991-04-09 1992-07-14 Glentech Inc. Diffuser efficiency

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2683366A (en) * 1949-02-26 1954-07-13 Kulvik Gunnar Washing arrangement for fibrous materials
US2712488A (en) * 1949-11-12 1955-07-05 Brax Antti Jussi Method and apparatus for washing pulp
US2964047A (en) * 1957-04-02 1960-12-13 A C Alvin Company Cleansing container and closure therefor
US3053069A (en) * 1957-08-21 1962-09-11 Sunds Verkst Er Aktiebolag Towers for bleaching pulp material, especially cellulose pulp
US3419466A (en) * 1964-10-12 1968-12-31 Anglo Paper Prod Ltd Method and apparatus for washing pulp

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1214152A (en) * 1915-11-05 1917-01-30 Albert Legrand Genter Method and apparatus for cleansing filter mediums.
SE225814C1 (enrdf_load_stackoverflow) * 1965-03-25 1969-03-25

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2683366A (en) * 1949-02-26 1954-07-13 Kulvik Gunnar Washing arrangement for fibrous materials
US2712488A (en) * 1949-11-12 1955-07-05 Brax Antti Jussi Method and apparatus for washing pulp
US2964047A (en) * 1957-04-02 1960-12-13 A C Alvin Company Cleansing container and closure therefor
US3053069A (en) * 1957-08-21 1962-09-11 Sunds Verkst Er Aktiebolag Towers for bleaching pulp material, especially cellulose pulp
US3419466A (en) * 1964-10-12 1968-12-31 Anglo Paper Prod Ltd Method and apparatus for washing pulp

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3905766A (en) * 1968-09-18 1975-09-16 Sunds Ab Method for the liquid treatment of, primarily, cellulosic pulp
US4975148A (en) * 1988-12-06 1990-12-04 Ahlstromforetagen Svenska Ab Cold blow system for batch production of pulp
US5027620A (en) * 1990-02-26 1991-07-02 Kamyr Ab Diffuser with flexible bellows and internal actuator
CN110656529A (zh) * 2019-09-12 2020-01-07 中国制浆造纸研究院有限公司 一种微细纤维及其制备方法和应用以及一种电气设备所用隔膜的制备方法
CN110656529B (zh) * 2019-09-12 2021-11-30 中国制浆造纸研究院有限公司 一种微细纤维及其制备方法和应用以及一种电气设备所用隔膜的制备方法

Also Published As

Publication number Publication date
FR1560832A (enrdf_load_stackoverflow) 1969-03-21
DE1761175C3 (de) 1975-07-10
FI53992C (fi) 1978-09-11
DE1761175B2 (de) 1974-11-21
US3729961A (en) 1973-05-01
NO132697C (enrdf_load_stackoverflow) 1975-12-17
DE1761175A1 (de) 1970-10-08
SE324950B (enrdf_load_stackoverflow) 1970-06-15
NO132697B (enrdf_load_stackoverflow) 1975-09-08
GB1205292A (en) 1970-09-16
FI53992B (fi) 1978-05-31
SE324950C (sv) 1977-02-28

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