Abstract: Process and apparatus for dispersing fibrous paper stock that includes delivering an aqueous fibrous paper stock, pressing some water out of the aqueous fibrous paper stock to form a highly consistent coarse fibrous paper stock, and introducing the highly consistent coarse fibrous stock into an effective area of a mallet roll having circulating mallets which cooperate with fixed peripheral impact sections. In this manner, the highly consistent coarse fibrous stock is loosened and distributed. The process also includes transporting the highly consistent fibrous paper stock into a dispersing machine, and dispersing the highly consistent fibrous paper stock in a dispersing machine.

Abstract: The invention relates to a process system and a method for preliminary treatment of disintegrated cellulose-containing material, preferably wood chips, prior to pulp digestion. The process system and the method according to the invention make use of a process vessel intended to function both as a so-called chip bin and as a pre-impregnation vessel. The characteristics of the invention are that a sloping steaming vessel is arranged downstream of the process vessel for the purpose of separating an excess of pre-impregnation liquid from the pre-impregnated cellulose-containing material, that the sloping steaming vessel is arranged for supplying steaming vapor which preferably has been generated by flashing of extraction liquor from a pulp digester, and that the sloping steaming vessel is connected to a chip chute communicating with a condenser for connection to a system for managing foul-smelling process gases.

Abstract: This process involves feeding cellulose into an extruder with an acid solution. The extruder is comprised of a screw and a barrel. The screw is rotated so as to pressurize the cellulose, and the cellulose undergoes acid hydrolysis and forms microcrystalline cellulose. The invented process can be accomplished by using pure cellulose or a lignocellulosic material as the starting material. If a lignocellulosic material is used, then a basic solution is added to it and the lignocellulosic material is fed through an extruder so as to obtain a mixture comprising lignin, hemicellulose and cellulose. The lignin and hemicellulose are extracted and the remaining cellulose is processed, as discussed previously, to form microcrystalline cellulose.

Abstract: In a pulp treatment vessel, such as a kraft pulp continuous vertical digester, a cellulose slurry is caused to flow in the vessel interior in a flow path. A substantially annular void is formed at at least one point along the flow path, and dilution or treatment liquor is introduced into the substantially annular void so that the liquor is substantially uniformly distributed about the periphery of or into the slurry. The annular void may be formed by a step out in the vessel, and the uniform introduction of dilution liquor may be accomplished utilizing one or more openings, such as a plurality of openings substantially evenly spaced around the substantially annular void, e.g. using a screen surface. The screen surface may be substantially vertical or conical.

Abstract: A system is provided for feeding wood or annual plant chips to continuous digesters for producing paper pulp. The system comprises two stages: in a first, impregnation stage, the chips are impregnated with a sufficient amount of chemical reagents to allow them to be hot-digested by impregnation in alkaline or alkaline-earth solutions, then drained. In the case of annual plants, the plants are mechanically mixed with alkaline and/or alkaline-earth reagents and a minimal quantity of hot water to obtain a wet fiber-like mixture. In the second stage, the material impregnated above is pumped directly into a pressurized digester (1) by a hydraulic piston pump (2). A plug (4) formed in the pipe (3) between the pump and the digester provides the required seal and pressure resistance.

Abstract: Methods for mixing a treatment agent with a pulp suspension are disclosed including supplying the pulp suspension to a mixing chamber, moving the pulp suspension through a mixing zone with the mixing chamber, supplying the treatment agent to the moving pulp suspension across the entire width of the mixing chamber prior to the mixing zone, and in which the height of the mixing zone is sufficiently small such that the pulp suspension and the treatment agent are subjected to kneading within the mixing zone in order to repeatedly stretch and compress fiber flocks in the pulp suspension. Apparatus for mixing the treatment agent with the pulp suspension are also disclosed.

Abstract: A two stage ozone-pulp bleaching method and apparatus are disclosed. In the first stage, high consistency pulp particles are turbulently mixed and contacted with a gaseous mixture containing ozone to mix and contact substantially all of the pulp particles with ozone to react at least a portion of the pulp particles with the ozone. Pulp particles and gaseous bleaching mixture are then directed to a second stage including a quiescent pulp bed. Pulp particles may complete their reaction in the bed, which also serves to strip ozone which was not contacted with pulp particles in the first stage from the gaseous bleaching mixture.

Abstract: A mass tower for medium or high consistency fiber suspension includes a vertically elongated circumferential side wall defining a space for receiving the fiber suspension. The bottom portion of the mass tower is filled with a material in an amount and of sufficient strength, preferably sand, gravel or concrete, to support the weight of the fiber suspension above the filling material. The filling material forms a bottom surface in contact with the fiber suspension and has an opening therein. Within the filling material is formed a flow channel in communication with the opening and extending through the filling material towards the side of the bottom portion for allowing the fiber suspension to be discharged from the mass tower. A method of manufacturing a mass tower and a method of converting an existing mass tower is also disclosed.

Abstract: A process for conditioning an ozone gas recycle stream in an ozone pulp bleaching process, wherein the level of carbon dioxide in the recycle stream is controlled to allow full capacity operation of the ozone generator. Carbon dioxide concentration is identified over the relevant operational ranges and maximum concentration is identified for full capacity/optimum efficiency operation. Specific methods are described for controlling carbon dioxide concentration including purging a portion of the recycle stream, counter-current scrubbing of the recycle stream with an alkaline solution and passing the recycle stream through an adsorbent material. Contaminants entering the system also may be reduced by directing the purged recycle stream, which is relatively oxygen rich, into the dewatering press where pulp consistency is increased. In this manner nitrogen surrounding the pulp is displaced by oxygen and thus, does not enter the bleaching/ozone system with the pulp.

Abstract: A process of preparing a suspension of paper making fibers in water for use in the making of paper includes the steps of treating a mass of fibrous materials, such as shredded waste paper materials, with steam under pressure in a closed vessel, and transferring the resulting mixture of treated materials and steam to a second vessel containing a substantial volume of aqueous liquid in such manner that the mixture impacts directly the liquid in the second vessel at very high velocity causing disintegration of the solid materials into essentially separate fibers and contaminant particles accompanied by dispersion of these solids in the liquid in the second vessel. Systems are described for carrying out these process steps on either a continuous or a batch basis.

Abstract: The process and the continuously working installation are intended for the extraction or flushing out of a substance from a heterogenous system with a solid phase of fibrous or granular material by means of a liquid, which, in the course of the process, forms a liquid phase which is increasingly loaded with the substance to be extracted or flushed out. The solid phase (2) is advanced in the installation with conveyor means (9. 9', 9"). the liquid phase (4, 4', 4") passes through the installation substantially in the opposite direction to the solid phase. Elements (30, 31, 32, 30', 31', 32', 30", 31", 32") for compressing and decompressing the solid phase (2) are disposed along the path of the solid phase (2) through the installation which may consist of several treatment stages (5, 5', 5") connected in series. Means for drawing off at least a part of the liquid phase are foreseen in each of the compression zones.

Abstract: An arrangement for discharging medium consistency pulp in connection with diffeent pulp treatment devices or apparatuses, the arrangement having a mass chamber, which is arranged between a screw discharging pulp from a pulp treating apparatus and a centrifugal pump transferring the pulp further so that both the screw and the pump are substantially at the same horizontal level with the pulp treatment apparatus. Thus, the presence of a drop leg having a height of several meters is prevented, whereby the centrifugal pump has no need to pump the pulp upwards back to the height of the pulp treatment apparatus.

Abstract: An apparatus for dewatering and squeezing a water containing material comprises a drum with a sieve mantle defining two co-operating drum sections, each comprising a feed screw extending therein. The first section of the drum in the feed direction is formed for dewatering of the material mainly by self-drainage. The first drum section is rotatable and is provided with means for cleaning the sieve mantle holes. The second section is formed for increased compression of the material, and has a thread height for the feed screw smaller at the outlet of the second section than at the inlet to this section.

Abstract: A synergistic combination of high-shear mechanical disruption and alkali pretreatment in a high solids reaction mixture constitutes a significant improvement in the alkaline peroxide treatment of lignocellulosic materials. The simultaneous application of these conditions greatly reduces the amounts of reagents otherwise required, and also eliminates the waste stream of liquid byproducts. Suitable sources of substrate treatable by this process include nonwoody plant parts, crop residues, and agricultural byproducts. The products of this treatment are nontoxic and characterized by high cellulose availability. These products are thereby useful as carbohydrate sources in ruminant feeds, as microbial feedstocks, and as sources of dietary fiber for humans and other monogastrics.

Abstract: In the method for the manufacture of a paper pulp for currency use from a stock comprising textile fibers, the operations of boiling, bleaching, chopping, breaking, cutting and washing of the textile fibers are performed in at least one treatment machine (10, 40) of the type having two co-rotating screws, in a plurality of phases taking place successively and continuously. The operations include a phase of feeding and mixing the stock with water, at least oen compression phase, at least one phase of shearing of the textile fibers, at least one phase of treatment of introduction of boiling and bleaching reagents, at least one phase of washing of the bleached pulp by introduction of washing water, and a phase of transferring and evacuating the bleached and washed pulp.

Abstract: A method of preparing a pulp for digestion in a continuous process from a fiber-containing cellulose material is described.

Abstract: A decker comprises a tank having a thickening drum mounted rotatably therein and including a filtering shell. The inside of the drum communicates with an inlet for feeding mass, whose consistency is to be increased during the thickening process and outlets for discharging the thickened mass after the thickening process. The filtrate separated from the mass being thickened, is arranged in a flow communication from the inside of the thickening drum through the filtering shell of the drum to the bottom portion of the tank. At least one separating member is placed in the bottom portion of the tank outside the drum and forms a partition point or partition line situated transversely with regard to the direction of rotation of the drum and at a predetermined, angular distance from the horizontal plane coinciding with the axis of rotation.

Abstract: In a refiner (40) with two opposed discs (47,48) rotatable relative to each other fibre pulp is manufactured from lignocellulose-containing material. The material is advanced in a channel comprising a plug pipe (20), through which the material is fed in compressed state, and a steam screen pipe (32) for discharging steam. The steam screen pipe (32) is located directly after the plug pipe (20) and has a cross-sectional area, which slightly exceeds that of the plug pipe in order to allow a limited expansion of the material plug. The steam is thereby allowed to flow through the material, at the same time as the material plug prevents clogging of the apertures (37,39) of the steam screen pipe.

Abstract: An elongated, imperforate housing (2) has a slurry inlet port (5) at one end and a pulp discharge port (6) at the other end. A pressing section (2b) within the housing is in direct fluid communication with the inlet port, and extracts liquid from the slurry by passing the slurry through a first compression restriction (108) to produce a pressed pulp. An annular washing section (2c) within the housing is positioned immediately downstream of, and in direct fluid communication with, the first compression restriction. The washing section has radially inner (109) and outer (14) cylindrical walls defining an annular washing chamber (110) for decompressing, diluting, and washing the pressed pulp. The washing is accomplished by injecting a washing liquid into the washing chamber through the inner wall, and simultaneously through the outer wall while the mixture is agitated. A repressing section (2d) within the housing is in direct fluid communication with the washing section, for receiving the conveyed mixture.

Abstract: A method for producing low fines content pulp having successive treatment stages in each of which compressive and shearing forces are applied to the cellulosic fiber while simultaneously one or more chemicals are added. Gradual breakdown of the fibers is achieved with resulting low fines production whereby the pulp may be used for tissue, fluff and towel products.

Abstract: A chemical pulping process is disclosed wherein wood chips are partially defiberized such that the fibers in the chips are substantially separated from one another but sufficient interfiber bonding is maintained to preserve chip integrity and thereby provide chips having an open porous fibrous network; and the chips are subjected to chemical pulping at an elevated temperature to remove a majority of the lignin in the chips.

Abstract: Apparatus for feeding wood chips and the like into a treatment bin includes a feed tube assembly adapted to lead into the bin at a non-zero angle relative to the horizon. A plate is supported underneath the lower end of the feed tube assembly to collect in a mound wood chips fed through the feed tube. The height of the lower end of the feed tube assembly is adjusted so that the lower end of the feed tube assembly engages the mound of wood chips and thereby forms a seal with the mound. A plow is supported between the plate and the lower end of the feed tube assembly. Either the plate is stationary and the plow rotates or the plow is stationary and the plate rotates to knock wood whips from the mound off the plate. The apparatus optionally includes a feed screw mounted within and longitudinally of the feed tube assembly to compress the wood chips into the mound.

Abstract: For bleaching cellulose pulp or a fraction thereof, e.g. reject pulp, the cellulose pulp or fraction, having a concentration of 0.5-10%, preferably 3-6%, is introduced into a screw press comprising at least a first (47) and a second (48) dewatering zone, is dewatered in the first zone to a concentration of 20-40%, whereupon a liquor of bleach chemicals is introduced centrally into the pulp which, during continued treatment, is dewatered in the second zone to a discharge pulp concentration of 15-50, preferably 15-30%, the liquid pressed out of the second zone, together with fresh bleach chemicals, being returned to the pulp in the screw press as liquor of bleach chemicals.

Abstract: A method and apparatus are provided for effecting presteaming and deaeration of wood chips, or like comminuted cellulosic fibrous material. Presteaming takes place in a vertical presteaming vessel, utilizing a plurality of uniformly radially spaced nozzles adjacent the bottom of the vessel, a plurality of generally uniformly radially spaced steam introduction pipes in a central portion of the vessel, and a pair of synchronized rotating valves for feeding steam to the introduction nozzles and pipes in a coordinated manner. After presteaming, the chips pass through a chips meter to a vertical chute in which they are entrained in liquid, and then pass to a horizontal deaerating vessel. In the deaerating vessel, deaerated liquid is passed in a path generally perpendicular to the path of the material flowing through the deaeration vessel.

Abstract: An apparatus for continuously producing wood pulp from wood shavings comprising a screw which rotates within a hollow cylinder. The hollow interior of the cylinder is divided into a pressure zone and a grinding and bleaching zone, the shavings being subjected to at least partially defibrillation under a high, continuously-increasing pressure in the pressure zone and then being simultaneously further defibrillated and bleached in the grinding and bleaching zone. The grinding and bleaching zone includes a plurality of pin planes, each plane being formed of at least three radially extending pins which project through the wall of the cylinder, the planes being spaced apart along the length of the screw.

Abstract: A process and apparatus for producing pulp from impregnated cellulose-containing starting materials such as wood, straw, grass, waste materials etc. in a compacting apparatus comprising a shell (1) and two mutually opposite pistons (4, 4') contained in the shell. The material to be compacted is disposed between the pistons and constitutes a resistive electrical load. The pistons are movable relative to each other and the shell is movable relative to the pistons. The impregnated starting materials are digested at a relatively low hydromodulus of 0.5 to 2 with a direct action of heat on the impregnated starting materials in the compacting apparatus at a digesting temperature of 160.degree. to 300.degree. C. The digesting times are short and depend on the digesting temperature.

Abstract: Methods and apparatus for separating vapor from refined cellulosic material are disclosed. The method includes discharging the refined cellulosic material downwardly through an inlet opening into a discharge chamber maintained at substantially the same pressure as the refiner, deflecting the vapor laterally with respect to that cellulosic material, passing the vapor through the discharge chamber at a flow rate of less than 15 meters/sec. so that the cellulosic material carried by the vapor is separated from the vapor by sedimentation, and discharging the cellulosic material from the discharge chamber.

Abstract: Method and apparatus for producing fiber pulp of improved paper-forming characteristics from ligno-cellulose-containing material such as wood chips and the like. The pulp material is subjected to a defibrating process in at least two steps. In the first step, the pulp material is disintegrated in a defibrator to form a flocculent mass of initially separated and freed fibers. This flocculent mass is then passed through a screw compacting device in which it is subjected to compression of a magnitude of 1 to 5 times the volume of the initially separated fibers. The compressed and highly concentrated mass of initially separated fibers is then passed into a refiner wherein the fibers are finally separated and fibrillated to form the final pulp.The refining is performed at a dry content of about 25-30%.

Abstract: Process and apparatus are provided for continuously conveying particulate compressible fibrous material from a first zone at a first gas pressure to a second zone at a second gas pressure with a pressure differential therebetween of at least 0.5 bar while retaining the prevailing gas pressure in each zone, which comprises:(1) continuously compressing the particulate material in the first zone into a gas-containing but gas-impermeable mass extending across the interface between the two zones;(2) continuously passing the mass of material out from the first zone into the second zone while maintaining the gas pressure within the mass constant at the gas pressure of the first zone; and(3) continuously breaking up the mass entering the second zone into particulate material.

Abstract: The continuous treatment of a cellulosic material in the form of chips to produce at least partial delignification of the material without true mechanical grinding is effected in apparatus comprising two parallel meshing screws which are rotated in the same direction in a sheath and have identical threads providing a plurality of zones of different pitch. The material is passed in succession through a first zone for feeding the material downstream, a first braking zone for causing a first compression of the material, a second zone for feeding the material downstream and in which the material is brought into contact with a reagent, e.g. steam or a chemical reagent, and a second braking zone for causing a second compression of the material.

Abstract: A method and apparatus for continuous oxygen bleaching of cellulosic pulp is provided utilizing first and second pressurized chambers with a number of tubes in fluid communication with both of first and second chambers. Oxygen bearing fluid is intimately mixed with digested cellulosic pulp and is continuously fed under pressure to the first chamber. Communication is selectively provided between the first and second chambers through at least one of the tubular members to allow passage of pulp from the member to the second chamber. The tubular member through which pulp flows to the second chamber is progressively changed as are the members through which passage is blocked, so that the pulp remains within each tubular member sufficient time to allow oxygen-bleaching thereof without degradation, and passes through the members without channelling. The oxygen bleached pulp is continuously discharged from the second chamber. The passage of pulp through the tubular members may either be downwardly or upwardly.

Abstract: Lignocellulose material is mechanically compacted and subjected to sudden pressure increase by exposure to saturated steam in a digestor vessel in the absence of added chemical reagents to obtain a cooked material which is then mechanically compacted while under said saturated steam pressure. Small portions of the cooked and mechanically compacted material are thereafter subjected to rapid reduction in pressure down to atmospheric pressure and then recovered in a condition of enhanced digestibility by ruminants.

Abstract: A method and apparatus for presteaming of wood chips and the like. The chips are treated in a vertical presteaming vessel with steam under low pressure, and removal of the air from the chips is facilitated by maintaining the presteaming vessel substantially at or near atmospheric pressure. An exhaust fan, controlled by a pressure probe in the presteaming vessel, may be provided for maintaining the pressure in the vessel. The amount of air that can enter the vessel through the chips inlet is minimized by an inclined rotating screw assembly with a partial flight which elevates the packs and chips to form an isolation seal at the chips inlet into the vessel.

Abstract: Cellulose fibers are treated by providing the fibers in a 10-90% concentration in liquid, and applying elastic pressure shocks to the fibers for a duration not exceeding one second and of a magnitude causing the pressure in the interior of the fibers to exceed 0.2 atmospheres excess pressure. Thereafter the fibers are permitted to expand. The pressure shocks cause liquid to be expelled from the fibers without permanent deformation of the fibers occurring. When the fibers expand, liquid is adsorbed. These steps are repeated until the fibers are completely impregnated with liquid. This prevents the formation of fiber knots when the fibers are substantially dried before being formed into paper. The elastic pressure shocks can be applied by a rotating paddle wheel which intermittently elastically compresses the fibers against an elastic surface of a container.

Abstract: An apparatus and method for the displacement impregnation of cellulosic chips material with digesting liquid. Cellulosic chips material and liquid are fed from a source to a high pressure transfer valve whereat the pressure of the chips and liquid is boosted. The chips are fed from the high pressure transfer valve through a feed system to the topmost portion of a vertical treatment vessel, the vessel having a topmost portion and an impregnation zone in an upper portion thereof below the topmost portion. A countercurrent flow of digesting liquid in the vessel impregnation zone is established to impregnate the chips material with digesting liquid, and displace the water and minerals therefrom, and liquid withdrawn from the top of the treatment vessel is withdrawn into the feed system. The withdrawals insure that essentially no free water enters the impregnation zone. A chips plug is established at the vessel top through which all withdrawn liquid must pass.

Abstract: Lignocellulose fiber containing chips, preheated with steam liberated from a previous chip defibration, are dewatered and then defibrated in an atmosphere of saturated steam and in the presence of backwater and suspended in backwater to form a pulp suspension whereafter wet sheets are formed from the pulp suspension, water is mechanically removed from the wet sheets and recycled as backwater to be supplied simultaneously, with dewatered chips, to the defibration step and to form a new pulp suspension and said wet sheets are dried.

Abstract: A screw thickener to be used for dewatering fibrous materials and being provided with a stuffing means at the discharge end. Said screw thickener having a hydrostatic superpressure of at least 10 kPa and said stuffing means being actuated by pulling means.

Abstract: Dewatering and homogenizing apparatus comprising a screw thickener at the discharge end provided with a plug forming means actuated by pulling means. At the thickener's discharge end there is also mounted a hood for receiving dewatered pulp and with supply means for homogenizing agent.