Abstract: The problems of non-uniform treatment of paper pulp that may be caused by differential flow velocities within a vessel, channeling, and/or disruption of the pulp flow, are substantially eliminated by providing a non-circular cross-section substantially atmospheric pressure vessel with at least one screen surface, and typically a liquid introducing device. The vessel, screen surface, and liquid introducing device are constructed and positioned with respect to each other so that during the treatment of a pulp slurry the slurry has substantially uniform width in a treatment zone, and there is substantially uniform resistance to the flow of slurry over the screen surface over any particular cross-section of the vessel in the treatment zone, and its consistency varies less than 6% in the treatment zone (e.g. between 8-14%).

Abstract: The problems of non-uniform treatment of paper pulp that may be caused by differential flow velocities within a vessel, channeling, and/or disruption of the pulp flow, are substantially eliminated by providing a non-circular cross-section substantially atmospheric pressure vessel with at least one screen surface, and typically a liquid introducing device. The vessel, screen surface, and liquid introducing device are constructed and positioned with respect to each other so that during the treatment of a pulp slurry the slurry has substantially uniform width in a treatment zone, and there is substantially uniform resistance to the flow of slurry over the screen surface over any particular cross-section of the vessel in the treatment zone, and its consistency varies less than 6% in the treatment zone (e.g. between 8-14%).

Abstract: Dense, tramp material, is efficiently separated in a comminuted cellulosic fibrous material feed system, for example in a chemical cellulose digester feed system, in a simple but effective matter. By merely utilizing a generally vertical conduit and a slurry flow within it (which may be augmented by high speed liquid introduction), that is caused to turn in a radiused path, centrifugal force allows separation of the tramp material into a cavity beneath the radius transition without requiring any mechanical element to engage the slurry. Appropriate purges, baffles, and discharge mechanisms may be provided. Alternatively, a tramp material separator may be built into an otherwise conventional metering screw in a digester feed system, or one or more centrifugal separators can be provided downstream of the slurry pump in a chip slurry transport system or digester feed system.

Abstract: Dense, tramp material, is efficiently separated in a comminuted cellulosic fibrous material feed system, for example in a chemical cellulose digester feed system, in a simple but effective matter. By merely utilizing a generally vertical conduit and a slurry flow within it (which may be augmented by high speed liquid introduction), that is caused to turn in a radiused path, centrifugal force allows separation of the tramp material into a cavity beneath the radius transition without requiring any mechanical element to engage the slurry. Appropriate purges, baffles, and discharge mechanisms may be provided. Alternatively, a tramp material separator may be built into an otherwise conventional metering screw in a digester feed system, or one or more centrifugal separators can be provided downstream of the slurry pump in a chip slurry transport system or digester feed system.

Abstract: The problems of non-uniform treatment of paper pulp that may be caused by differential flow velocities within a vessel, channeling, and/or disruption of the pulp flow, are substantially eliminated by providing a non-circular cross-section substantially atmospheric pressure vessel with at least one screen surface, and typically a liquid introducing device. The vessel, screen surface, and liquid introducing device are constructed and positioned with respect to each other so that during the treatment of a pulp slurry the slurry has substantially uniform width in a treatment zone, and there is substantially uniform resistance to the flow of slurry over the screen surface over any particular cross-section of the vessel in the treatment zone, and its consistency varies less than 6% in the treatment zone (e.g. between 8-14%).

Abstract: Dense, tramp material, is efficiently separated in a comminuted cellulosic fibrous material feed system, for example in a chemical cellulose digester feed system, in a simple but effective matter. By merely utilizing a generally vertical conduit and a slurry flow within it (which may be augmented by high speed liquid introduction), that is caused to turn in a radiused path, centrifugal force allows separation of the tramp material into a cavity beneath the radius transition without requiring any mechanical element to engage the slurry. Appropriate purges, baffles, and discharge mechanisms may be provided. Alternatively, a tramp material separator may be built into an otherwise conventional metering screw in a digester feed system, or one or more centrifugal separators can be provided downstream of the slurry pump in a chip slurry transport system or digester feed system.

Abstract: A high pressure transfer device for feeding wood chips to a digester in the production of paper pulp has enhanced efficiency. A rotor having first and second sets of through extending conduits is mounted for rotation in a housing having first through fourth ports associated with each set, with a screen at the third port of each set for screening wood chips out of liquid passing through that third port. The third port of each set is connected to its own distinct source of suction, so as to enhance filling efficiency of the rotor.

Abstract: A high pressure transfer device for feeding wood chips to a digster in the production of paper pulp has enhanced efficiency. A pocketed rotor is mounted for rotation in a housing having first through fourth ports, with a screen at the third port for screening wood chips out of liquid passing through that third port. This screen is blanked at the leading edge in the direction of rotation so that as a pocket rotates into operative association with the first and third ports, the pocket inlet has an arcuate extent of about two inches which is exposed to the first port --large enough to allow chips to start flowing freely into the pocket--before the outlet of that pocket is exposed to a suction source in communication with the screen.

Abstract: Immediate and accurate control of a pulp refiner is provided so as to control the degree of refining in the production of mechanical pulp, such as RMP, TMP, and CTMP. The mechanical pulp discharged from a refiner is fluidized by a fluidizing centrifugal pump, the fluidizing action instantaneously removing the pulp latent properties. A sample of the latency-removed pulp is then subjected to a pulp freeness measurement, and that freeness measurement is supplied to a computer. The computer utilizes the freeness measurement, as well as other measurements such as pulp consistency and flow rate measurements, and dilution flow measurements, and in response to the inputs control refiner parameters to ensure that the freeness of the mechanical pulp being produced is within the desired range. The refiner parameters controlled can be the hydraulic plate loading (refining pressure), and/or the tonnage of fiber supplied to the refiner.

Abstract: A method and apparatus for the treatment of fiber material by oxygen bleaching. Digested cellulosic fiber material is treated with oxygen to reduce the Kappa number thereof further to about 15 or below. The reaction products are removed immediately after formation, and during the oxygen bleaching process. The fiber material is at a first consistency of about 8 to 15% consistency, and treatment with oxygen is accomplished by mixing the pulp with O.sub.2, NaOH solution, and water to thereby form an integral mixture of pulp with oxygen at a second consistency, thickening the integral mixture to return it to generally its first consistency, and repeating the mixing and thickening until pulp of a desired Kappa number (15 or below) is reached. The pulp is then washed and may be subsequently treated to reduce the Kappa number thereof to any desired value. A thickener is used which can thicken pulp at superatomspheric pressures and at a temperature greater than 100.degree. C.

Abstract: A process for continuously monitoring and controlling a continuous process for digestion of cellulose utilizing a computer which is programmed to determine (1) the mass of wood being fed to the digester from measurements of the density of the wood slurry feed, the density of the liquid and the total flow of slurry, (2) the mass of wood being withdrawn from the digester from measurements of the density of the pulp slurry, the density of the liquor and the total flow of slurry, (3) the correct amount of fresh digester liquor to be added concurrently with the wood feed and (4) amount of water wash and makeup digester liquor to be fed to the reactor. The computer can also be programmed to control the temperature in the reaction zone of the digester.

Abstract: A method and apparatus for the delignification of cellulosic fiber material to minimize the amount of reject material in the final pulp produced. The fiber material is digested, washed, oxygen delignified, and passed through a screening stage to provide a main pulp stream, and a reject stream from the separation stage. The flow and consistency of the separated reject material is determined, the reject material is refined, and sufficient chemical is added to the separated reject material, based upon the flow and consistency thereof, so that subsequent delignification of the reject material may be effected. This may be accomplished either by passing the reject material through a separate oxygen delignification stage and then returning it to the main pulp stream, or adding caustic to it and soaking it in a soak tank for predetermined period of time, and then returning it to the main pulp stream before the oxygen delignification stage therein.

Abstract: An assembly and method for determining the level of sound absorbing solids in a fluid-filled vessel. A number of sound receivers are mounted at spaced vertical positions to the exterior of the vessel along a generally vertical line, and a sound generator is mounted atop the vessel approximately 180.degree. around the circumference of the vessel from the receivers. The sound waves are intermittently or cyclically generated by the sound generator, they are received by the receivers, and evaluated. For those receivers mounted below the level of the solids, the energy received will be low, while for those mounted above the solids level in the fluid phase of the vessel, the energy received will be high. For cellulosic chips, the receivers are tuned to respond primarily to sound at a frequency of about 3200 Hz.

Abstract: A process for continuously digesting cellulosic fibrous material wherein the degree of delignification of the cellulosic fibrous material in the digestion zone is continuously determined and monitored by determining the exothermic heat of the delignification reaction taking place in the digester. The exothermic heat of the delignification reaction is determined by measurements of the temperature rise occurring in the delignification zone and the heat capacity of the cellulosic material and digesting liquor.

Abstract: An improved process for continuously monitoring and controlling a continuous process for digestion of cellulose utilizing a computer which is programmed to determined (1) the mass of wood being fed to the digester from measurements of the density of the wood slurry feed, the density of the liquid and the total flow of slurry, (2) the mass of wood being withdrawn from the digester from measurements of the density of the pulp slurry, the density of the liquor and the total flow of slurry, (3) the correct amount of fresh digester liquor to be added concurrently with the wood feed and (4) amount of water wash and makeup digester liquor to be fed to the reactor. The computer can also be programmed to control the temperature in the reaction zone of the digester.

Abstract: An apparatus and method for the digestion of cellulosic fiber material providing pulp of very uniform quality. Cellulosic fiber material entrained in treatment liquid is fed into a top portion of a first vertical treatment vessel, impregnation of the fiber material with treatment liquid taking place in the first vessel. A first flow path of fiber material entrained in and impregnated with treatment liquid is established from the bottom of the first vessel to a top portion of a separate second vertical treatment vessel, liquid substantially filling the second vessel. Liquid is withdrawn from the top portion of the second vessel (without screening) and a second flow path is established of the liquid withdrawn from the second vessel back toward the bottom portion of the first vessel, heating of the liquid during transport in the second flow path taking place.

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: A process for providing pressurized, pulverized coal for use in combustion or gasifying of coal by the fluidized bed or suspended particle combustion principles which comprises the steps of introducing lump coal, of stoker size to run of mine size, into a low energy liquid circulation stream; transferring the lump coal to a high energy, high pressure, liquid circulation stream; separating the lump coal from the high energy liquid circulation stream by lifting the coal through a free liquid surface, said high energy liquid draining from the coal by gravity; directing the coal by gravity transfer to a continuous mechanical dryer for removal of surface liquid; gravity transfer to a coal crusher for major size reduction; gravity transfer to a coal pulverizer for size reduction necessary for the gasification processes; transfer of pulverized coal by gas circulation from the pulverizer to a cyclone separator, said circulating gas used in the pulverizer for coal particle classifying; and final injection of the pulve