Abstract: A wide variety of end products may be manufactured from fibers or fiber pulp derived from feathers. Examples of such end products are paper and paper-like products, non-woven and woven fibers, insulation, filters, extrusions, and composite sheets and plates.

Abstract: In the pulp washing machine and method therefor, pulp to be washed is fed between the rotating drum and the pressing roll inside it, so that pulp passes along a spiral-formed track around the pressing roll, being thereby pressed several times. Washing liquid is fed to the pulp at one or several points along its track of movement, between the pressings and/or at the pressing position. Washing thus takes place partly as a diffusion and partly as a displacement washing process. Washing is efficient and reduces the breaking of pulp fibers down to a minimum.

Abstract: The invention relates to a method and a device for feeding out fiber pulp over an overflow rim (2) at the upper end of a cylindrical container (1), through which the pulp, which is suspended in liquid, is being fed continuously from the bottom and upwards. The distinguishing features are that the pulp is diluted at a level below the upper surface of the pulp by means of a multiplicity of diluting nozzles (15A-D), which extend downwards in the pulp and which are rotated around the vertical center line (12) of the container, and that the pulp, which has been fed upwards through the container, and the diluting liquid are mixed with each other to form an essentially homogeneous suspension with the aid of rotating scraper elements (14A-D) which extend downwards in the surface layer of the suspension and, at the same time as they are homogenizing the mixture, feed the suspension outwards towards, and finally over, the overflow rim.

Abstract: An apparatus and process for the solvent pulping and washing of pulp using vessels purged of oxygen free gas when the process is arrested or terminated. The washing is accomplished by first continuously passing the pulp to a pressure diffuser, then to a first multi-stage drum displacer washer, and then to a second multi-stage drum displacer. In the pressure diffuser the lignin is washed out of the pulp, utilizing as wash liquid a mixture of solvent and water having a solvent concentration equal to or higher than that required by the extraction process within the digester, and at a pressure at least about 350 psi. The pressure in the second and third stages is lower, and water is the wash liquid in the third stage. Alcohol can be recovered from the spent wash liquid of the first wash stage, so that all but about ten gallons or less of alcohol per ton of pulp is recovered.

Abstract: A defoamer composition made from the reaction product of an epoxide containing composition selected from epoxide fatty acids, epoxide vegetable oils and mixtures thereof and at least one secondary compound selected from the group consisting of fatty acids and alkoxylated derivatives thereof, alkoxylated polyols, alcohols, alkoxylated alcohols, alkylphenols, alkoxylated alkylphenols, alkylamides, alkoxylated alkylamides, acetylenic glycols, alkoxylated acetylenic glycols, polybasic acids, alkylene oxides, organo silicones and polymers thereof, and methods of using the same especially for defoaming black liquor produced in the pulp and paper industry.

Abstract: Methods for discharging spent cooking liquors from a batch digester containing cooked lignocellulose-containing material in spent cooking liquor are disclosed, including supplying a first portion of washing liquid to the digester to displace a first portion of the spent cooking liquor at a temperature and dry solids content which substantially corresponds to the temperature and dry solids content of the spent cooking liquor at the end of the batch digestion, supplying a second portion of washing liquid to the digester to displace a second portion of the spent cooking liquor having a temperature and dry solids content substantially lower than that of the spent cooking liquor in the digester, and maintaining the first and second portions of spent cooking liquor separate from each other. Methods of producing kraft pulp in batch digesting processes using this method are also disclosed.

Abstract: Ethyleneamines are used in washing pulp to remove lignin. A process for washing a cellulose pulp mixture containing lignin to remove at least a portion of the lignin therefrom comprises use of a washing composition with at least about 100 ppm of an ethyleneamine. The process includes an improvement in a washing process a cellulose pulp mixture containing lignin wherein a washing composition is used to remove at least a portion of the lignin, the improvement comprising use of at least about 100 ppm of an ethyleneamine with the washing composition and/or using an amount of ethyleneamine at least equivalent to about 100 ppm based on the washing composition with the washing composition. The washing composition is also novel and includes a washing composition for washing kraft pulp comprising water and at least about 100 ppm of an ethyleneamine.

Abstract: The present invention is directed to a method for increasing the retention on a washing/thickening device in an aqueous papermaking system. The method generally comprises adding to the furnish solids of the system an effective amount of a cationic polyacrylamide polymer.

Abstract: A defoaming composition of the following formula: ##STR1## wherein R is a hydrocarbon radical of from 10-20 carbon atoms and made be either saturated, unsaturated and either linear or branched in structure; R.sup.1 is a reactive alkoxy radical of from 2 to 4 carbon atoms; y is an interger of at least 1; A is an ethylene. propylene, or butylene group; and x is an integer of at least 1. The above composition can be used with oil-based defoaming aqueous system. The defoaming composition and process for defoaming are included.

Abstract: A method of washing cellulosic pulp to remove dissolved solids as well as dirt, inorganic fillers and fiber debris from the pulp. A thin mat of cellulosic pulp having a weight of 3 to 100 pounds of dry fiber per 1000 sq. ft. is applied to the upper surface of a porous, endless belt or fabric. The belt containing the pulp mat is moved in a generally horizontal path, and as it is moved in this path wash water is directed against the exposed upper surface of the mat through a series of longitudinally spaced showers to thereby impregnate the mat with wash water. Water removal devices, preferably table rolls, are located beneath the belt and downstream in the direction of travel from each shower to thereby remove the wash water from the mat. After moving through the path of travel, the washed pulp is removed from the belt, and the wash water removed from the mat can be used in other portions of the papermaking process.

Abstract: A method of manufacturing chemical pulp out of comminuted cellulosic fiber material comprising digesting the fiber material with digestion liquid without preceding peroxide stage. According to the invention the comminuted fiber material is treated in at least one stage prior to said digestion, in the presence of a liquid containing at least one compound having the ability to form complexes with metals existing naturally in the fiber material.

Abstract: In a pulp digester for continuous cooking under raised pressure and temperature of fiber material in a vertical digester (1), input of fiber material and cooking liquid takes place at the top of the digester, withdrawal of spent cooking liquor is carried out from at least one digester screening arrangement (1D) between the top and the bottom of the digester, and fiber material is fed out from the bottom (1C) of the digester, and at least one screening arrangement (2) in the lower half of the digester, wherein at least one of said screening arrangements (1, 2) has at least one screen element (2A) of which the main configuration is of angular shape, preferably rectangular, most preferred square, having a screen face (3A) of which the total area is less than 1 m.sup.

Abstract: A method and apparatus for treating wood pulp that includes incompletely washed brownstock, in which the brownstock is treated at a pH range of approximately 7.0 to 9.0 with a hemicellulase enzyme preparation that has a pH optimum below 6.0. Also, a method and apparatus for treating wood pulp containing incompletely washed brownstock in which the brownstock is treated at a pH range of approximately 6.0 to 9.0 with a hemicellulase enzyme preparation that has a pH optimum below 6.0 and that has a low cellulase content such that not more than about 10,000 FPU are added per ton of pulp.

Abstract: Improved apparatus for dewatering or washing a suspension of paper pulp in which first and second rolls are rotatably mounted with an endless loop of wire tensioned around the rolls, and in which a headbox delivers a pulp suspension to be thickened or washed and positioned with an outlet to discharge the pulp suspension into or onto the wire as it approaches the first roll, and in which the washed or dewatered pulp is collected after it has passed between the wire and a second roll, in which the first roll has a central shaft, and screw flighting on the shaft formed in left and right-hand sections are terminated at cylindrical discs mounted at opposite ends of the shaft, and in which the screw flighting has a depth which is substantially greater than the maximum thickness of the pulp layer and in which the aggregate open area between the screw flights is substantially greater than the cross-sectional area of the headbox outlet to assure that the spaces between the flights can be no more than partially filled

Abstract: Process for high pH metal ion chelation in pulps. Extraction and removal of detrimental metal ions and organic solvent extractives prior to delignification and bleaching is carried out on pulp, preferably kraft pulp, at a pH over 5, more preferably a pH over 6, most preferably a pH of 7-9. Aqueous pulp is first brought to a pH of about 3-6 to cause chelation and desorption of metal ions from the fiber phase of the aqueous pulp, and at the same time implementing air entrainment and evaporation. The pH is then raised, and the extractable species are removed by dewatering and washing the pulp.

Abstract: Located within the annular screen of the pressure diffuser is a tubular baffle hung from adjacent the top of the vessel. The baffle has two headers disposed on its inner surface, with openings in the tube providing communication between the exterior of the tube and the headers. A conduit extends from each header to an arm at the top of the vessel, to allow extracted liquid to be discharged. Another extraction conduit is provided at the bottom of the vessel, in communication with the screen interior and the tubular baffle interior. Treatment liquid, such as wash liquid, may be introduced at two, three, or more positions along the vessel with the liquid extracted from the first and second headers being introduceable at different positions along the vessel. A flexible, elastomeric material, sealing element with integral annular skirt may extend from the bottom end of the tubular baffle and engage the screen to provide a seal minimizing mixing between stages.

Abstract: A multi-stage pressure diffuser is provided for treating paper pulp or similar comminuted cellulosic fibrous material. Two different subvolumes are defined within the annular screen of the pressure diffuser by a tubular baffle hung from adjacent the top of the vessel, and a transverse wall near the middle of the vessel. Wash liquid is introduced into the top stage, extracted liquid passes through the bottom of the baffle, and is removed through a liquid outlet at the top of the vessel. That removed liquid is then reintroduced into the bottom stage as wash liquid, and the extracted liquid from the bottom stage is discharged from the vessel at the bottom. The screen assembly may be blanked at the area of the transverse wall dividing the subvolumes from each other, in order to minimize the possibility of mixing of the extraction flows in the different stages.

Abstract: The invention relates to a diffuser, comprising a substantially cylindrical, vertical container, through which cellulose pulp is arranged to be transported, nozzle arms, for delivering a fluid, such as washing liquid, to the pulp, concentrically disposed screen surfaces and screen arms disposed on and connected to said screen surfaces for withdrawal of said fluid. The screen arms are provided, at their outer ends, with withdrawal pipes, directed substantially vertically downwards, which are slidably controlled and are connected in sealing arrangement to outlets for said fluid. The invention relates also to a stuffing box designed to receive a rod, preferably a pull rod for raising and lowering a screen pack having screen surfaces in a diffuser, said rod being guided in sealing arrangement and slidably through a fixture which is mounted in a bearing for free movement in a plane substantially perpendicular to said rod.

Abstract: A process for the treatment of absorbent sanitary paper products to separate such products into components thereof in a form suitable for recycling or re-use is disclosed; absorbent sanitary paper products include disposable diapers, incontinence products, feminine hygiene products, bedpads and other related absorbent and adsorbent products. The process comprises the step of treating said products in at least one bath of an aqueous solution to remove particulate and/or soluble matter from the products. The bath is operated under conditions that are conducive to non-destructive separation of said products into components thereof. In preferred embodiments, the treated product thus obtained is treated with at least one aqueous washing solution and with at least one aqueous solution of at least one of bleaching agent and antimicrobial agent, and separate streams of plastic and cellulosic materials are recovered. The process results in the recovery of usable products from absorbent sanitary paper products.

Abstract: A method for washing a fibre suspension including the steps of feeding the suspension into an annular displacement space, supplying a fluid through a permeable outer surface of the space, rotating the space to establish a fibre layer between the fluid supplied through the permeable outer surface of the displacement space and a remaining part of the fibre suspension.

Abstract: A pressurized dynamic pulp washer including an annular hollow housing in which the stock is driven axially along a plurality of stationary, annular, coaxial wash filters in axially reversible directions, with an annular rotatable shell between the wash filters to urge liquid through openings in the filters, to generate axial, radial and circumferential velocities in the slurry to create localized pulses in the slurry to urge liquid through the filters with wash liquid being introduced to replace liquid filtered from the fibers in the slurry.

Abstract: Recyclable containers such as corrugated or folding boxes are made from a coated paper or kraft grade sheet including a plastic coating thereon. Aqueous acrylic resin containing compositions can be applied in excess on the paper or kraft grade sheet and the unwanted coating metered and removed by directing a jet of air at the coating. After solidification of the coating, the coated paper or kraft sheets can be incorporated as components of corrugated or folding boxes. Recovery of the unwanted coating permits recycling of the coating component. Corrugated and folding boxes including the components can be recycled by conventional repulping processes. A process of manufacture of the coated sheets is also disclosed.

Abstract: The invention relates to a method and device for the washing of a medium consistency fibrous slurry, especially a chemical pulp slurry in which the slurry is fed at an inclined angle onto a substantially horizontal portion of circulating filter belt, and then distributed over substantially the entire working width of the filter belt. The distributed slurry is then washed with a washing liquid under localized pressure to produce a slurry having a medium consistency range, i.e., about 8 to 15 percent. In order to increase the consistency to 20 to 40 weight percent, preferably about 30 to about 35 weight percent, the washed slurry is passed to a pressing zone.

Abstract: A pulp dewatering and washing apparatus comprising a pressure vessel in which is contained a table assembly having a foraminous surface, in the form of a conveying belt, on which a pulp slurry is deposited. A differential pressure chamber in the table assembly is vented to a lower pressure location to cause a pressure differential across the pulp slurry to cause dewatering. Also, wash water is deposited on the dewatered pulp in sequential cycles to accomplish washing. A contact plate is provided to press the pulp slurry to aid in dewatering. The conveying belt of the table assembly on which the pulp slurry is deposited is stationary during the dewatering and washing, and then after the pressure differential between the vessel and the pressure differential chamber is reduced to zero, the conveyor belt moves the dewatered and washed slurry to a discharge location.

Abstract: A method and apparatus for the treatment of fiber suspensions of the pulp and paper industry, in particular, the so-called postscreening of pulp in the bleaching stage. The method includes that the pulp discharged from a bleaching stage is diluted to the screening consistency, that the pulp is screened in a pressure screen and that the accept fraction is supplied to the subsequent treatment stage at the supply consistency of the stage without a separate thickening stage. The screening is preferably carried out in a narrow-slot screen.

Abstract: A wire-type pulp washing machine includes an endless moving foraminous wire which extends about a breast roll defining an on-running end and a couch roll defining an off-running end with a generally horizontal upper run of the wire extending between the rolls with showers providing a counter-current washer. The endless wire forms a wire return run having a horizontal wire section beneath the upper run. Pulp which has been washed on the upper counter-current washer may be removed and subjected to a chemical action, such as a bleaching action, and then reapplied to a horizontal return run section of the wire by a headbox to form a pulp mat on the inside surface of the wire. This pulp mat is subject to further countercurrent washing by the application of wash water to an upper surface of the mat and by draining of the wash water through the wire by suction boxes. This wash water may advantageously be applied as the wash water to the last stage of the counter-current washer along the upper run.

Abstract: A method for enhancing pulp washing efficiency is disclosed. An anionic sulfonate surfactant is added within the washing or pulping operation to enhance the removal of lignin and spent cooking chemicals from pulp.

Abstract: A pressure diffuser is constructed so that the compression of pulp that normally occurs during rapid movement of the screen assembly does not significantly degrade the efficiency of the washing (or other treatment liquid) action in the diffuser. This is accomplished by providing at least two headers, including a first vertical header and flow control assembly for one or more sets of horizontal treatment liquid conduits adjacent the pulp inlet to the diffuser, and a second vertical header and flow control assembly for one or more horizontal treatment liquid conduits remote from the pulp inlet. The first and second vertical headers may comprise a common pipe with a flow preventer precluding flow between them, or distinct pipes supplied with treatment liquid by a common pump. The advantageous results are further achieved by providing at least one ring [mounted between the outer screen and the concentric inner support cylinder of the screen assembly] with a plurality of rapid-flow restricting openings.

Abstract: Apparatus for treating pulp with a treating liquid, comprising a vessel (1) with cylindrical wall (2), inner screening means (3) for withdrawing liquid from the pulp, and a plurality of distributing tubes (5) on the outside of the vessel for the supply of treating liquid into the vessel through a plurality of inlet connections (6). According to the invention each distributing tube (5) is formed of an annular section (20) and an opposing part (21) of the cylinder wall (2), the section being welded directly to the cylinder wall, and the section and the cylinder wall part enclosing between them a distributing channel (22). Furthermore, each inlet connection (6) is provided with an opening (23) extending through the cylinder wall part and connecting the distribution channel to the interior of the vessel.

Abstract: Method in the washing of alkaline, cellulosic pulp, for example sulphate pulp, CTMP and CMP pulp, the washing being effected in at least one stage. By an addition of carbon dioxide, there will be realized greatly reduced washing losses of, primarily, inorganic ions, as well as improved washing-out of substances which give rise to chemical oxygen demand (COD).

Abstract: The invention concerns a drum washer. The washer has two plates (14; 18) located after each other in parallel with the drum, and the pulp to be washed is conducted between these plates. Between the plates there is a gap (22) closed by a flap valve (25) by way of which gap washing liquid is conducted through the mat. The washer is especially suitable for washing cellulose pulp.

Abstract: A method of removing fine contaminants from waste paper fibrous material (S) is described with solution (1) and pre cleaning (2) whereupon the fibrous material is first subjected to a washing treatment (3) and then to a flotation treatment (5). The washing filtrate (12) from the washing treatment (3) is cleaned in a filtrate-flotation treatment (4) so that a cleaned fraction (14) can be returned into the useful material (13) of the washing treatment. The so cleaned waste paper fibrous material can be passed to further treatment steps such as flotation, bleaching and/or dispersion. The reject material from the filtrate-flotation (4) is, in one embodiment, again subjected to a flotation treatment.

Abstract: A process is disclosed for bleaching pulp without chlorine containing chemicals and for greatly reducing total washing filtrate discharge, comprising the steps of: 1) sending pulp that has been subjected to continuous digestion, oxygen-delignification and then washing, through a washing press; 2) treating, with agitation, the delignified washed pulp with sulfuric acid and a chelating agent; 3) washing the pulp in a washing apparatus; 4) bleaching with hydrogen peroxide in a reaction vessel; 5) washing the hydrogen peroxide bleached pulp; 6) adding sulfuric acid and ozone with mixing of the pulp; 7) reacting the pulp with ozone in a reaction vessel; and 8) washing the ozone reacted pulp, wherein the majority of liquid filtrate from the bleaching process that is waste not to be recycled is drawn off from the washing apparatus of step 3, the washings in step 3 and 5 have at least 85% efficiency, filtrate from washing step 5 is recirculated to the washing apparatus of step 3, and filtrate from the washing apparat

Abstract: A process for enhancing pulp washing efficiency is disclosed. An anionic surfactant is added within the washing or pulping operation to enhance the removal of lignin and spent cooking chemicals from pulp.

Abstract: A method for washing a fibrous suspension. The fibrous suspension is dearated with a deaerating centrifugal pump as it is pumped into the washing zone. The washing water is also dearated with a deaerating centrifugal pump.

Abstract: A flat bed, Fourdrinier-type, countercurrent washer for cellulosic pulp incorporates a pressing section at the downstream end thereof which includes the couch roll and additional rolls that carry out multiple mechanical pressing operations on the pulp after it has been subjected to multiple stages of displacement washing without mechanical treatment. As a result, where such washers without mechanical pressing deliver pulp of a consistency of the order of 15% solids, this washer increases the pulp consistency to as high as 40% while correspondingly increasing the effectiveness of the washing operation as a whole.

Abstract: In the bleaching of paper pulp without chlorine, such as using an OTZE or OZP bleach sequence, filtrate from subsequent stages is used as a wash liquid in preceding wash stages. The filtrate is treated with a fiber filter, and then passes through a magnesium filter, which has magnesium chips with a maximum dimension of about 3 mm or less. The magnesium removes heavy metal ions, and if any of the magnesium dissolves in the filtrate it provides a beneficial affect on the pulp. The pH of the filtrate is typically maintained in the 2-6 range to facilitate dissolution of Cu, Mn and Fe while the magnesium stays out of solution. Two filters may be provided in parallel so that if one becomes contaminated the other may be quickly put into service, and any explosive gases from the magnesium filter are vented.

Abstract: The invention concerns the recycling of waste paper in a deinking process with flotation with at least one other cleaning stage downstream. According to the invention, selective flotation is performed in multiple stages. After no more than a third flotation stage, the flotation foam collected up to that point is removed and purified by means of flash flotation, which produces sludge, clear water and separated foam that contains the contaminants from the waste paper feed. Subsequently, the sludge is removed from the paper recycling process. Large impurities are removed from the sludge (foam) (except for the foam from up to the three last stages) in up to two washing units (including thickeners) or screen units. The fibers are then separated from the relatively fine contaminants, and these contaminants are primarily removed as sludge from the resulting low-fiber fractions by flash flotation.

Abstract: A process for bleaching wood pulp is provided comprising subjecting the wood pulp, after brown stock washing, to an oxygen delignification stage, a washing sequence, a first chlorine dioxide bleaching stage, an oxidative extraction stage, at least one final chlorine dioxide bleaching stage and then recycling the filtrate from the oxidative extraction stage countercurrently through the bleaching plant and brown stock washing. Additionally, and quite beneficially, the filtrate from the first chlorine dioxide bleaching stage is also recycled countercurrently through the brown stock washing thereby significantly reducing the environmental impact associated with the manufacture of bleach wood pulp.

Abstract: Brown stock washing of wood pulp is improved by adding a water-soluble cationic polymer to the wash water. The cationic polymer reacts with lignin solution present in the larger channels in the pulp mat to give a precipitate which lowers the flow rate of wash water through the larger channels. A more efficient wash water usage is obtained.

Abstract: The invention relates to a process for bleaching chemically delignified lignocellulose-containing pulp, to render more efficient a peroxide-containing treatment stage, by treating the pulp with a complexing agent before the peroxide step, so that the trace metal profile of the pulp is altered by the treatment with the complexing agent, in the absence of sulphite, at a pH in the range from 3.1 up to 9.0 and at a temperature in the range from 10.degree. C. up to 100.degree. C., whereupon, in a subsequent step, the treatment with a peroxide-containing substance is carried out at a pH in the range from 7 up to 13, said two-step treatment being carried out at an optional position in the bleaching sequence applied to the pulp.

Abstract: A process for delignifying and bleaching a lignocellulosic pulp without the use of elemental chlorine by partially delignifying the pulp to a K No. of about 10 or less and a viscosity of greater than about 13 cps; and further delignifying the partially delignified pulp with an effective amount of ozone for a sufficient time to obtain a substantially delignified pulp having a K No. of about 5 or less, a viscosity of greater than about 10, and a GE brightness of at least about 50%. The substantially delignified pulp may be brightened by the addition of a bleaching agent such as chlorine dioxide or a peroxide to obtain a final product having a GE brightness of at least about 65%, preferably above 70% to as high as 90%. Because of the absence of elemental chlorine in this sequence, filtrate from all stages but the chlorine dioxide stage (if used) can be recovered without sewering. Major environmental improvements are thus achieved.

Abstract: A control system for a countercurrent pulp washing process in which the pulp is formed as a pulp mat on at least one moving filter surface and the mat is supplied with rinse water to replace water in the pulp mat thereby reducing the soda loss in the mat before it is removed from the filter surface. The process is characterized by at least one predictable process variable including dissolved solids retained in the pulp mat. The system comprises a trainable neural network having a plurality of input neurons having input values applied thereto and output neurons for providing output values and means for training the neural network to provide predicted values for the predictable process variables.

Abstract: A wire-type pulp washing machine includes an endless moving foraminous wire which extends about a breast roll defining an on-running end and a couch roll defining an off-running end with a generally horizontal upper run of the wire extending between the rolls with showers providing a counter-current washer. The endless wire forms a wire return run having a horizontal wire section beneath the upper run. Pulp which has been washed on the upper counter-current washer may be removed and subjected to a chemical action, such as a bleaching action, and then reapplied to a horizontal return run section of the wire by a headbox to form a pulp mat on the inside surface of the wire. This pulp mat is subject to further countercurrent washing by the application of wash water to an upper surface of the mat and by draining of the wash water through the wire by suction boxes. This wash water may advantageously be applied as the wash water to the last stage of the counter-current washer along the upper run.

Abstract: Method for treating chemically treated cellulosic pulp that contains sodium ions wherein the pulp is subjected to an ion exchange with a cation (preferably calcium) having a higher valence than the sodium followed by washing of the sodium cations from the pulp and then forming the pulp containing the cations in an amount equivalent to at least 700 ppm of calcium ions into a sheet thereby to facilitate water removal and increase the production rate of the sheet forming machine.

Abstract: Method and apparatus for treating a gas containing aqueous fiber suspension in a fiber line process of a pulp mill including at least one of pulp screening, washing and bleaching includes (a) transferring the gas containing fiber suspension at a consistency to a treatment station; (b) treating said fiber suspension at the same level by removing a portion of the water from the fiber suspension so as to generate aqueous filtrate and treated fiber suspension having a relatively higher consistency; (c) simultaneously pumping and degassing the filtrate at the same level; and (d) pumping the treated fiber suspension having the relatively higher consistency away from the treatment station at the same level by imparting to the treated fiber suspension sufficient shear force so as to render the fiber suspension pumpable.

Abstract: A cylinder type paper pulp washer or thickener apparatus includes a rotatable cylinder mold with a forming wire surface. The mold rotates at least partially submerged in a vat of dilute paper pulp stock and a differential pressure across the wire surface draws stock from the vat through the cylinder mold and forms a pulp mat on the wire surface, and a plurality of disrupters are positioned within the vat and in arcuately spaced relation to the wire surface to cause a disruption of the fiber mat which obstructs the flow of the stock liquid through the wire surface and thereby provides for the reestablishment of flow. Various disrupters are shown, including a rotating non-circular bar, a doctor blade, a foil, a fluid jet, a brush, and a triangular protuberance. A plurality of such disrupters are positioned in peripherally spaced relation to cause repeated disruption and reformation of a fiber mat to increase the throughflow and washing or thickening efficiency of the apparatus.

Abstract: A pressurized dynamic pulp washer in which stock is driven along a stationary wash wire and pulses are generated in the stock to urge liquid through openings in the wash wire. Wash liquid is introduced countercurrent to the flow of stock, and localized mixing and reslurrying occurs.

Abstract: The invention relates to a method and device for the washing of a medium consistency fibrous slurry, especially a chemical pulp slurry in which the slurry is fed at an inclined angle onto a substantially horizontal portion of circulating filter belt, and then distributed over substantially the entire working width of the filter belt. The distributed slurry is then washed with a washing liquid under localized pressure to produce a slurry having a medium consistency range, i.e., about 8 to 15 percent. In order to increase the consistency to 20 to 40 weight percent, preferably about 30 to about 35 weight percent, the washed slurry is passed to a pressing zone.

Abstract: A method of defiberizing fibrous cellulosic material bound by chemical bonds and physical force comprising treating the fibrous cellulosic material in a treatment apparatus so as to loosen the chemical bonds between the fibers but to leave the bonds caused by physical force essentiall undisburbed to generate treated fiber accumulations and removing a stream of the treated fiber accumulations from said treatment apparatus and defiberting the treated fiber accumulations by subjecting the material to shear forces in the stream, the shear forces being of sufficient strenth to substantiallyl break the physical forces keeping the fibers together and to separate the fibers.