US3096234A - Continuous digesting system - Google Patents

Continuous digesting system Download PDF

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Publication number
US3096234A
US3096234A US770424A US77042458A US3096234A US 3096234 A US3096234 A US 3096234A US 770424 A US770424 A US 770424A US 77042458 A US77042458 A US 77042458A US 3096234 A US3096234 A US 3096234A
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liquor
pulp
digester
press
dilution tank
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US770424A
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Armstrong Bruce
William J Nolan
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NOLAN
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NOLAN
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Priority to US770424A priority Critical patent/US3096234A/en
Priority to FR808657A priority patent/FR1239179A/fr
Priority to FI1769/59A priority patent/FI40851B/fi
Priority to DEA33146A priority patent/DE1267076B/de
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Publication of US3096234A publication Critical patent/US3096234A/en
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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
    • D21C3/00—Pulping cellulose-containing materials
    • D21C3/22—Other features of pulping processes
    • D21C3/24—Continuous processes

Definitions

  • This invention relates to a continuous digester system for producing pulp and, more particularly, to a continuous digester system lhav-ing improved mechanisms for introducing the chips to Ithe digester and withdrawing the cooked pulp therefrom.
  • the liquor ratio that is, the ratio of the weight of chemical solution to weight o-f dry wood has always been kept at a minimum, and, more specifically, ⁇ a liquor ratio of between 3.0:1 and 4.011 has in the past been used in order to minimize both the heat required to bring the ⁇ digester charge to cooking temperature and the heat required to evaporate the spent black liquor.
  • the second serious fault inherent in low liquor ratios is the necessarily high concentration of digestion chemicals needed at the start of the cook in order to insure a sufficiently high 4concentration near the end of the cook to supply driving force for the digestion reaction. If the liquor ratio can be increased without economic penalty, the .initial concentration of digestion chemicals therein can be markedly reduced, the strength of the liquor near the end of the cook being just ⁇ as high as if -a high ⁇ chemical concentration, low liquor ratio cook were performed. It the digester can be designed to permit the use of high liquor ratios, any suitable low initial concentration may be used. This provides .a lchoice of various combinations of concentrations and temperatures not available with low liquor-wood ratios.
  • the invention provides .a means of changing the liquor/wood ratio at each successive step so that each step in the process is performed at the most favorable consistency.
  • the mixture of cooking liquor and Wood is pumped at approximately 4% consistency because pumps for this service perform best at this consistency.
  • the mixture of liquor and chips requires steam to bring the mixture up to digester temperature.
  • Four percent consistency is equivalent to 24 lbs. liquor per lb. of oven-dry wood. This would require an excessive amount of steam.
  • the No. 1 liquor transfer press removes liquor from the mixture until there remains only that liquor required to provide suicient chemical to react with and remove substantially all the lignin and leave a small residual of chemical to force the reaction right up to the end of the cook.
  • the chips are moved through the digester during which time the pulping reaction occurs.
  • the cooked pulp exi-ting from the digester is fed through a How sensing device and then to a second press where some of the spent digestion liquor is expressed therefrom. Part of this spent liquor is returned and mixed with 4the chips entering the digester and ⁇ the balance is sent to the recovery system.
  • the pulp ⁇ and spent liquor mixed therewith exiting from the press define the external liquor ratio which is la measure of the heat leaving the system and which, in any event, will be much less than the internal liquor ratio.
  • Suitable pressures are maintained on the streams entering and leaving the digester so that the chips are continuously fed thereinto and cooked pulp is removed therefrom while a suitable digesting pressure is maintained within the digester.
  • the transfer is designed to have an output consistency ranging from 20% to 40% As there are 24 pounds of liquor per pound of ovendry wood at 4% consistency, and from 4 pounds to 1'1/2 pounds at 20 and 40% respectively, the transfer will remove from 20 pounds to 221/2 pounds of liquor per pound of wood.
  • Heating up only 21/2 to 5 pounds of mixture of wood and cooking liquor to digester temperature would constitute an ⁇ attractive steam ⁇ demand but presents 1a diiiicult material handling problem; and does not provide la sufficient volume of yliquor to effectively wet :all Kthe chips in tlrir passage through the system.
  • spent black liquor from the second liquor transfer press 36 is re- 5 cycled to the digester and added to the high consistency mixture to dilute it to the desired liquor ratio.
  • This new liquor ratio may range from a low of 5 to 1 up to a high of to 1.
  • the recycle black liquor may be introduced by means of an injector which not only provides the necessary energy to inject the liquor but also provides the heat necessary to bring the mixture of chips and cooking liquor up to digester temperature plus the heat losses in the system.
  • the recycle black liquor and steam may be added directly to the digester or, preferably, mixed with the output of the liquor transfer press just prior to entering the digester.
  • a concentration for the original cooking liquor is selected so that the mixture of wood, cooking liquor, steam and recycle black liquor will give the desired starting concentration for the liquor ratio selected and (at the end of the cook) will give the required minimum residual concentration.
  • the cellulosic material which may be shredded chips prepared in accordance with the disclosures of application Serial No. 578,378, iled April 16, 1956, now abandoned, or ⁇ application Serial No. 369,740, tiled July 22, 1953, now U.S. Patent No.
  • 2,904,460 is fed, usually after being weighed, onto aV conveyor 10.
  • the chips are fed by the conveyor into a mixing tank 11 and yfresh digestion liquor, sometimes hereinafter referred to .as white liquor, is added thereto.
  • the white liquor is ordinarily at the temperature at which it is pumped from the causticizing system, usually in a range of 150l80 F.
  • the white liquor is pumped :by a pump 13, through a meter 14 Iand a valve 15, into the tank.
  • the valve 15 is controlled by a liquid level control 16.
  • Sullicient White liquor is added to the tank 11A so that the chips therein can be kept in uniform suspension by the agitator 12 and can be read-ily pumped.
  • the quantity of white liquor may be varied to provide a consistency within the range of 2-10% and is not critical, since ⁇ all excess :over digester requirements is removed by the first liquor transfer press 18 and is returned to the mixing tank, No. 11.
  • the chip suspension discharged from the tank 11 passes through a pump 17 to the first liquor transfer press 18.
  • la primary purpose of the pump 17 is to provide a hydrostatic pressure sullicient to equalize or slightly exceed the steam pressure in the -digester plus what ever friction is developed in the system.
  • Many types of pumps may be used for this purpose, such as a high-head centrifugal, a multi-stage centrifugal or a progressive cavity pump.
  • the rst liquor transfer press 18 may be substantially the same as that shown in U.S. Patent No. 2,664,814 and consists yof Ia screw of decreasing pitch, said screw rotating in a perforated barrel.
  • the annular area of the press decreases from the entrance lto the exit thereof.
  • the amount lof white liquor in contact with the chips as the chips leave the press determines the external liquor ratio and is so selected that it is sutiicient to insure completion of the desired pulping reaction.
  • the press 18 does not operate against digester pressure. Rather, there is la hydrostatic pressure built up by the pump 17 equal to or slightly greater than the steam pressure in the digester i9.
  • the pressed chips, entering the digester 19, are mixed with spent liquor from the ⁇ discharge end of the digester.
  • the spent liquor is substantially at full digester pressure, for example, at 150 pounds per square inch and 366 F.
  • the chips and their accompanying white liquor, before mixing with the spent liquor are at a temperature in the range of about 150 to 180 F. Since the spent liquor mixed at this point is substantially at digester temperature and pressure the only ⁇ steam required will be that amount necessary to heat the chips and white liquor from the press 18 to the digester temperature, in this example, 366 F. plus the heat losses of the system. Thus, steam requirements are held .to a minimum.
  • the spent liquor substanatially yat full digester Itemperature and pressure, is forwarded from :the spent liquor storage tank 2l through the conduit 22.
  • a valve 23 is provided in conduit 22 and the setting of said valve is controlled by .a metering device 24 in order to maintain the proper rate of ilow of the spent black liquor.
  • the black liquor then passes into an injector unit 26 where steam is fed thereinto and then the mixture is injected into and mixed with the chips' exiting from the press.
  • the steam not only serves to -inject the ⁇ spent liquor into the digester but also serves to 4heat the chips and the white liquor to the ⁇ digester temperature.
  • the mixture of the white liquor and the chips from the press, the spent liquor and the condensed steam determinees the internal :liquor ratio, that is, the liquor to wood ratio within Ithe digester. It is obvious that the internal liquor ratio is h-igher than the external ratio and may be set at any desired value by adding more or less spent liquor without yany substantial penalty to steam economy. The only effect of increases in .the internal liquor ratio will be to decrease the pulp capacity of the digester.
  • the digester i9 may take a variety of dierent forms.
  • the ⁇ digester includes a cylindrical tank 28 having an inlet opening 29 at the bottom thereof ⁇ and an outlet opening 30 at the top thereof.
  • the diameter and length of the digester are adjusted so that a suiiicient volume will be provided to insure the required tonnage of production at the liquor-to-wood ratio selected and the proper retention time for the cook.
  • a slowly rotating screw 31 is disposed within the digester and is driven by a suitable motor 32, preferably having a ⁇ suitable variable speed driving mechanism.
  • the angle of the helix and the speed of rotation of the screw are selected so that the vertical component just equals the upward bul-k flow rate of the ⁇ suspension of chips and liquor in the digester.
  • This llow rate is a function of the net area of the digester and the volume of the suspension per unit of time.
  • Some of the chips may contain sufficient entrained air to cause them to tend to float rapidly to the top of the digester. However, the settling rate of over half of the chips in the suspension will normally be greater than the bulk liow rate and they will tend to settle out of suspension toward-s the bottom ⁇ of the digester. Either phenomenon would adversely aiect the uniformity of the iinished pulp.
  • a relief line 33 ⁇ is provided at the top of the digester for ⁇ drawing olf air, noncondensible gases and volatile organic compounds su-ch as turpentine, etc.
  • the capacity of the digester system may be increased by using one or more ⁇ of these digester bodies in series. For example, if the digester is of such dimensions and the pitch and speed of the screw are so designed to provide one hundredtons of pulp per ⁇ day at a cooking time of thirtyfive minutes and an internal liquor ratio of ten to one, production may be doubled by using two digester bodies in series. The speed of the pump 17, and transfer screw in this .case must be doubled so that the total retention time of the chips in the two ⁇ digesters together will be equal to the total cooking time of thirty-live m-inutes.
  • the cooked pulp leaves through the exit opening 30 and passes through a conduit 34.
  • the conduit has a suitable flow sensing ldevice 35, such as a magnetic flow meter, a venturi meter or a similar instrument, for providing a signal, either electrical, mechanical or fluid pressure, proportional tol the flow through the conduit 34.
  • a second liquor transfer press 36 which is similar to the transfer press 1S previously described.
  • the decreasing annular space and ⁇ decreasing axial pitch of the screw squeeze out the excess spent liquor which passes through the perforations in the barrel. Since the pulp and spent liquor are still at the digester temperature and pressure, the expressed spent liquor is also at the digester temperature and pressure, and it flows into the strong spent liquor storage tank 21.
  • a liquid level controller 37 in the strong liquor tank 2l insures that all of the spent liquor entering the tank, in excess of that used yfor recirculation, will be drawn oit through the conduit 38 to the recovery system. Since the liquor sent to the recovery system is also at digester temperature and pressure, its heat content can be used effectively in the evaporators of the recovery system.
  • the squeezed pulp will leave the liquor transfer press 36 at a consistency determined by the design of the press, for example, ranging from about 20 to about 40 percent dry liber.
  • the pulp is then fed to a ⁇ dilution tank 39 where a suitable diluent, such as dilute black liquor yfrom the pulp washers, normally at a temperature of 4to 150 F. is flowed thereinto and is mixed therewith by an agitator 41.
  • a suitable diluent such as dilute black liquor yfrom the pulp washers, normally at a temperature of 4to 150 F.
  • the quantity of black liquor from the washing system can be Ivaried to ygive any desired linal pulp consistency, such as from 240%, for 4pumping purposes.
  • the equilibrium temperature within the dilution tank 39 is always kept below 212 F.
  • a suitable gas pressure source is connected -thereto by a conduit 42, said ⁇ conduit having a control valve 43 therein.
  • the gas pressure source may be either air or some other non-condensible gas and, as shown, is usually compressed air.
  • the rate of flow being determined by the pressure differential between the pressure in lthe digester and the pressure in the dilution tank 39.
  • the ilow meter 35 in the conduit 34 is made to control the .rate of flow of the pulp into the dilution tank 39.
  • the meter transmits a signal to the pressure control valve 43 and this, in turn, increases the gas pressure in the dilution tank. This increase in gas pressure decreases the rate of pulp ilow.
  • the flow meter transmits a reverse signal to the gas pressure control valve 43, thereby reducing the pressure in the dilution tank 39 to provide an increase in pulp flow.
  • the pressure Within the dilution tank 39 controls the flow of pulp thereinto and by properly coordinating the flow sensing device 35 and valve 43 it is possible to attain a substantially steady continuous flow of pulp into said tank while maintaining proper pressure within the digester.
  • a liquid level controller 44 maintains a constant level of pulp suspension in the dilution tank 39. This level may be located in la portion of reduced cross-section of the tank so that a minimum, still surface of the suspension will :be presented to the gas phase, insuring a minimum of gas solution into the hot pulp suspension.
  • the liquid level controller 44 is used to vary the speed of the final stock pump 46 if a positive displacement pump is used; -or it may 'be utilized to Vary the opening of the throttling valve for adjustable orifice.
  • the pump 46 transports the dilute pulp suspension through a consistency regulator 47, thence to the pulp washing system.
  • a iiow meter 48 may, i-f desired, be used after the consistency regulator to indicate and record the pulp flow. lFrom this pulp iiow rate and the consistency provided by the regulator it is possible to compute the Weight of dry pulp being produced during a unit of time. At the other end of the digester system, the combination of recorded weight of chips and the moisture content of the chips as determined from lan automatic chip sampling device make it possible to calculate the weight of dry chips -fed to the digester system per unit of time. From these data a true value of pulp yield and tonnage may be obtained continuously making it possible to adjust the digester controls as required to insure uniformity of yield and production.
  • the digester system can be adapted for use with any suitable cellulosic raw material, such as wood, bagasse, cotton or flax stalks, bamboo stalks and other annuals.
  • the digesting liquor may be alkaline -White liquor as used in the kraft process, caustic soda as used in the soda process, lbisulphite liquor with a soda, magnesium, ammonium or calcium base; sodium sulphite and carbonate as used in the neutral sulphite semichemical process, or any other suitable digestant.
  • the end product may be a fully cooked pulp, a high yield pulp, or a semichemical pulp requiring further mechanical subdivision.
  • the pulping reaction is obliged to start in the digester at the outside surface of the chip and progress in a radial direction toward the center of the chip.
  • a continuous digestion system including: a digester, said digester having an entrance opening adjacent the lower end thereof and an exit opening adjacent the upper end thereof; a ro-tatable screw within said digester forming continuously upward moving compartments controlling the movement of the -chips suspended inl liquor fed into said digester through said entrance opening upwardly at the same rate as the liquor to said exit opening; a feed mechanism for feeding chips of cellulosic material to said digester, said feeding mechanism including a mixing tank for receiving chips and mixing same with digestion liquor to iform a pumpa'ole slurry, a pump connected for withdrawing the slurry from said mixing tank and pressurizing same to a value in excess of the pressure within said digester, a -rst liquor transfer press connected for receiving the pressurized slurry from said pump, said -first press including means for expressing liquid from the slurry as same passes therethrough without substantially changing the pressure on said -chips so that the chips exiting from said press are at a high consistency and are acted upon by
  • a .continuous digester system for cooking cellulosic material comprising:
  • ya iirst liquor transfer press for receiving material from said pump and for squeezing out liquor therefrom without changing the pressure thereon;
  • control device for produoing'a signal proportional to the rate of ilow of material therethrough and means for feeding the material exiting 4from the top of the di-gester through said control device to produce a signal therefrom;
  • a second liquor transfer press for receiving the material from the control device to express the hot spent liquor therefrom;
  • a continuous digestion system including:
  • a feed mechanism for continuously feeding chips of cellulosic material to said digester, said feeding mechanism including a mixing tank for receiving chips and mixing same with 4digestion liquor to form a pumpable slurry;
  • a pump connected for withdrawing the slurry from said mixing tank and pressurizing same to a value in excess ofthe pressure within said digester
  • a iirst liquor transfer press connected for receiving the pressurized slurry from said pump, said rst press including means for expressing liquid ⁇ from the slurry as same passes therethrough without substantially changing the pressure on said chips so that .the chips exiting from said press are at a high consistency ⁇ and are acted upon by pressure in excess of that necessary to move same into the digester;
  • a discharge mechanism for continuously withdrawing pulp from said digester, said discharge mechanism including a conduit connected to the discharge end of said digester;
  • a second liquor transfer press connected to said conduit for receiving pulp flowing therethrough, s-aid second press including means ⁇ for expressing digestion liquor from the pulp las same passes therethrough so that the pulp exiting ⁇ from said second press is at a high consistency;
  • a high pressure storage tank for receiving expressed liquor
  • control means for controlling the pressure within said dilution tank
  • liquid llevel controller connected to said dilution tank for maintain-ing a substantially constant liquid level therein;
  • a continuous digestion system including:
  • a digester said digester having an entrance opening ladjacent the lower end thereof and an exit opening adjacent .the upper end thereof;
  • a feed mechanism for feeding chips of cellulosic material t-o said digester, said feeding mechanism including a mixing tank for receiving chips and mixing same with digestion liquor to form a pumpable slurry;
  • a pump connected for withdrawing the slurry from said mixing tank and pressurizing same to a value in excess of the pressure within said digester
  • a first liquor transfer press ⁇ connected for receiving the pressurized slurry from said pump, said rst press including means for expressing liquid ⁇ from the slurry as same passes therethrough without substa-ntially changing the pressure on said chips so that the chips exiting from said press are at a high consistency and are acted upon by pressure suicient to move same intothe digester;
  • a .discharge mechanism for continuously withdrawing pulp from said digester, said discharge mechanism including a conduit connected to the discharge end of said digester;
  • a second liquid transfer press connected to said conduit ⁇ for receiving pulp flowing therethrough, said second press including means for expressing digestion liquor from the pulp as same passes therethrough so that the pulp exiting from said second press is ⁇ at a high consistency;
  • I control means for controlling the pressure of the nonicondensable gas applied to said ⁇ dilution tank
  • liquid level controller connected to said dilution tank for maintaining a substantially constant liquid level therein;
  • Y and pump means for withdrawing diluted pulp from the dilution tank in such a manner as to cause ⁇ a smooth controllable llow of pulp and a release Iof the dilution tank pressure thereon.

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US770424A 1958-10-29 1958-10-29 Continuous digesting system Expired - Lifetime US3096234A (en)

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Application Number Priority Date Filing Date Title
US770424A US3096234A (en) 1958-10-29 1958-10-29 Continuous digesting system
FR808657A FR1239179A (fr) 1958-10-29 1959-10-28 Installation de digestion continue
FI1769/59A FI40851B (fr) 1958-10-29 1959-10-29
DEA33146A DE1267076B (de) 1958-10-29 1959-10-29 Verfahren zum kontinuierlichen Kochen von Zellulosematerial

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DE (1) DE1267076B (fr)
FI (1) FI40851B (fr)
FR (1) FR1239179A (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5106456A (en) * 1988-01-05 1992-04-21 A. Ahlstrom Corporation Method and apparatus for facilitating the discharge of pulp
WO1997024486A1 (fr) * 1995-12-27 1997-07-10 A. Ahlström Osakeyhtiö Pompage de pulpes de consistance moyenne et de temperature elevee a partir de colonnes d'alimentation
WO1999014424A1 (fr) * 1997-09-15 1999-03-25 MELVILLE, Gordon, Brown Procede et appareil de fabrication de pate
US20050037109A1 (en) * 2002-12-02 2005-02-17 Stig Soerensen Apparatus and method for hydrolysis of a protein containing raw material and application of the resulting hydrolysis products
WO2010002348A1 (fr) * 2008-07-03 2010-01-07 Metso Paper, Inc. Procédé et appareil pour commander un écoulement d’une suspension de pâte
US9416491B2 (en) 2013-01-04 2016-08-16 Sulzer Management Ag Method of and an arrangement for transferring a process liquid, an industrial facility and a method of simplifying the layout of such

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE461280B (sv) * 1988-06-06 1990-01-29 Kamyr Ab Behandling av ett fiberhaltigt material foere kokning till massa

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1954012A (en) * 1930-02-17 1934-04-10 Lemberger Antonin Manufacture of cellulose and the like
US1982130A (en) * 1933-09-05 1934-11-27 Longview Fibre Co Chemical treatment process for pulp manufacture
US2038925A (en) * 1934-11-20 1936-04-28 Chemipulp Process Inc Method and apparatus for the treatment of fibrous material
FR852892A (fr) * 1938-11-09 1940-03-05 Maschb Scholz & Co Procédé et dispositif pour la cuisson continue de matières fibreuses cellulosiques, de caoutchouc, de racines coupées, etc., attaquées par un liquide chaud sous pression
US2542801A (en) * 1945-04-12 1951-02-20 Joaquin J De La Roza Sr Continuous digestion apparatus for the production of highly purified cellulose
US2607680A (en) * 1947-02-17 1952-08-19 Buckeye Cotton Oil Company Apparatus and method for processing vegetable fibers
US2673690A (en) * 1951-10-27 1954-03-30 Hercules Powder Co Ltd Method for the digestion of cellulose-bearing material
US2858213A (en) * 1956-04-20 1958-10-28 Condi Engineering Corp Wood chip digestion

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE404506C (de) * 1921-12-01 1924-10-18 A Olier Sa Des Ets Verfahren und Einrichtung zur Herstellung von Zellstoff aus holzhaltigem Rohstoff
US1505934A (en) * 1921-12-01 1924-08-19 Olier Sa Ets A Device for the continuous treatment of ligneous materials for their transformation in cellulose
DE592332C (de) * 1931-01-19 1934-02-05 Gunnar Planck Verfahren zur fortlaufenden Herstellung von Zellstoff
DE897948C (de) * 1951-12-21 1953-11-26 Kamyr Ab Verfahren und Vorrichtung zum kontinuierlichen Aufschliessen von Faserstoffen
DE966918C (de) * 1952-05-29 1957-09-19 Kamyr Ab Vorrichtung zur Entnahme von Zellulosematerial aus Druckbehaeltern
DE1048773B (de) * 1955-02-14 1959-01-15 Escher Wyss GmbH, Ravensburg Einrichtung zum kontinuierlichen Aufschließen pflanzlicher faserhaltiger Stoffe zu Zellstoff oder HalbzeJl stoff

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1954012A (en) * 1930-02-17 1934-04-10 Lemberger Antonin Manufacture of cellulose and the like
US1982130A (en) * 1933-09-05 1934-11-27 Longview Fibre Co Chemical treatment process for pulp manufacture
US2038925A (en) * 1934-11-20 1936-04-28 Chemipulp Process Inc Method and apparatus for the treatment of fibrous material
FR852892A (fr) * 1938-11-09 1940-03-05 Maschb Scholz & Co Procédé et dispositif pour la cuisson continue de matières fibreuses cellulosiques, de caoutchouc, de racines coupées, etc., attaquées par un liquide chaud sous pression
US2542801A (en) * 1945-04-12 1951-02-20 Joaquin J De La Roza Sr Continuous digestion apparatus for the production of highly purified cellulose
US2607680A (en) * 1947-02-17 1952-08-19 Buckeye Cotton Oil Company Apparatus and method for processing vegetable fibers
US2673690A (en) * 1951-10-27 1954-03-30 Hercules Powder Co Ltd Method for the digestion of cellulose-bearing material
US2858213A (en) * 1956-04-20 1958-10-28 Condi Engineering Corp Wood chip digestion

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5106456A (en) * 1988-01-05 1992-04-21 A. Ahlstrom Corporation Method and apparatus for facilitating the discharge of pulp
WO1997024486A1 (fr) * 1995-12-27 1997-07-10 A. Ahlström Osakeyhtiö Pompage de pulpes de consistance moyenne et de temperature elevee a partir de colonnes d'alimentation
US5851350A (en) * 1995-12-27 1998-12-22 A. Ahlstrom Corporation Method and apparatus for pumping cellulose pulp
WO1999014424A1 (fr) * 1997-09-15 1999-03-25 MELVILLE, Gordon, Brown Procede et appareil de fabrication de pate
US20110033889A1 (en) * 2002-12-02 2011-02-10 Marine Bioproducts A.S. Apparatus and method for hydrolysis of a protein containing raw material and application of the resulting hydrolysis products
US20050037109A1 (en) * 2002-12-02 2005-02-17 Stig Soerensen Apparatus and method for hydrolysis of a protein containing raw material and application of the resulting hydrolysis products
US8173014B2 (en) * 2002-12-02 2012-05-08 Marine Bioproducts As Apparatus for hydrolysis of a protein containing raw material and application of the resulting hydrolysis products
US9232812B2 (en) 2002-12-02 2016-01-12 Marine Bioproducts A.S. Apparatus and method for hydrolysis of a protein containing raw material and application of the resulting hydrolysis products
WO2010002348A1 (fr) * 2008-07-03 2010-01-07 Metso Paper, Inc. Procédé et appareil pour commander un écoulement d’une suspension de pâte
US20110139384A1 (en) * 2008-07-03 2011-06-16 Metso Paper, Inc. Method and an apparatus for controlling a flow of pulp suspension
US8177937B2 (en) 2008-07-03 2012-05-15 Metso Paper, Inc. Method and an apparatus for controlling a flow of pulp suspension
US9416491B2 (en) 2013-01-04 2016-08-16 Sulzer Management Ag Method of and an arrangement for transferring a process liquid, an industrial facility and a method of simplifying the layout of such
US9708762B2 (en) 2013-01-04 2017-07-18 Sulzer Management Ag Method of and an arrangement for transferring a process liquid, an industrial facility and a method of simplifying the layout of such

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Publication number Publication date
FI40851B (fr) 1969-02-28
FR1239179A (fr) 1960-08-19
DE1267076B (de) 1968-04-25

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