Abstract: A feed screw for feeding lignocellulosic material to a rotary disc refiner is disclosed. The feed screw includes at least one peripheral thread for feeding the lignocellulosic material axially towards the disc refiner and the feed screw feeds the lignocellulosic material from its upstream end towards its downstream end through the center of the opposed grinding surfaces of the disc refiner, the downstream end of the peripheral thread including an angled end part disposed at an angle with respect to the peripheral thread such that the lignocellulosic material is redirected in a radial direction as it leaves the end of the peripheral thread.

Abstract: The feed system is for a continuous digester where at least two pumps are arranged in parallel at the bottom of a pre-treatment vessel and a stirrer is provided in direct connection to inlets to pumps. The system makes it possible to provide a feed system with an improved accessibility and operational reliability, and to operate the main part of the pumps at optimal efficiency even if the production capacity is reduced.

Abstract: The feed system is for a continuous digester where at least two pumps are arranged in parallel in the bottom of a pre-treatment vessel and a liquid level of at least 20 meters is established. The system makes it possible to provide a feed system with an improved accessibility and more reliable operation, and to operate the main part of the pumps at optimal efficiency even if the production capacity is reduced.

Abstract: The invention relates to a method of producing a structured fibrous web of paper. The method comprises forming a fibrous web and conveying the formed fibrous web on a water receiving felt (5) to a dewatering nip. An endless belt (11) with a polyurethane surface is passed through the nip together with the fibrous web and the water receiving felt (5). After the dewatering nip, the fibrous web is conveyed by the endless belt (11) to an endless textured fabric (12) which is permeable to air and to which the web is transferred from the endless belt (11) in a transfer nip. The textured fabric (12) rans at a lower speed than the endless belt (11). After the transfer to the textured fabric (12), the fibrous web is carried by the textured fabric (12) to a drying cylinder (17). The transfer nip is formed by two rolls of which one is a suction roll within the loop of the textured fabric. The transfer nip has a length which is 5 mm-40 mm.

Abstract: The method, system and a withdrawal screen section are for the impregnation of chips during the manufacture of chemical pulp. Chips are both steamed and impregnated in a low pressure impregnation vessel, using pressurized hot spent cooking liquor BL as the main part of the impregnation liquid. The hot spent cooking liquor produces most of the steam BLST necessary for steaming the chips. At least two independent first and second screen rows, SC1 and SC1b respectively, are installed in order to improve the process in the impregnation vessel. The first screen row withdraws acidified treatment liquor for disposal which otherwise would be a parasitic acidified waste fluid in the system. The second screen row recirculates treatment fluid back to center of treatment vessel in order to even out the pH profile over the cross section of the vessel.

Abstract: The continuous digester is for producing pulp from comminuted cellulosic material. The digester has a cone diverter on a bottom scraper arranged in the bottom of the digester for assisting in out feed of pulp produced. The cone diverter of the bottom scraper has an upper inclined surface of the cone diverter with an inclination angle in the range 30±10 degrees in relation to the vertical. In order to improve washing performance in the bottom of the digester, especially for overloaded digesters, the upper inclined surface is equipped with draining apertures in fluid communication with a liquid receiving chamber inside the cone diverter. The liquid receiving chamber is connected via a drainage channel to the exterior of the vessel.

Abstract: The present invention relates to a press device (1) that comprises an extended nip roll (2) and a counter roll (3). The extended nip roll (2) has a flexible jacket (4) and a support body (5) inside the flexible jacket (4). The extended nip (2) roll also has internal means for causing the support body (5) to move or expand radially towards an inner surface (6) of the flexible jacket (4) to form a nip with the counter roll. The rolls (2, 3) have axial ends (7, 8, 10, 11) that are supported in bearing housings (9, 12). One or several actuators (13) such as hydraulic cylinders connects bearing housings (9, 12) to each other and the actuator or actuators (13) are arranged to act on the bearing housings (9, 12) to cause them to move to each other in a closing movement. A mechanical stop (14) which is separate from the rolls (2,3) is arranged to halt the closing movement. The invention also relates to a machine that uses the press device and to a method of operating the press device.

Abstract: The feed system is for a continuous digester where at least two pumps are arranged in parallel at the bottom of a pre-treatment vessel. The outlets of the pumps are combined at a merging point before a common transfer line extends to the top of the digester. The system makes it possible to provide a feed system with an improved accessibility and operational reliability, and to operate the main part of the pumps at optimal efficiency even if the production capacity is reduced.

Abstract: A method and apparatus for processing pulp is disclosed including opposed endless wires conveyed in the same direction and defining a web-forming space therebetween for dewatering the web, a pair of perforated dewatering tables supporting the endless wires for pressing the wires towards the web, the first perforated dewatering table ending upstream of the second perforated dewatering table, and a press roll downstream of the back end of the first perforated dewatering table and opposed to the back end of the second perforated dewatering table to form a nip between the press roll and the back end of the second perforated dewatering table, which has a profiled surface that interacts with the press roll to prolong the nip between the press roll and the back end of the second perforated dewatering table.

Abstract: The method is for retrieving heat from black liquor wherein the black liquor is withdrawn from a digester in association with the production of cellulose pulp. The black liquor at the withdrawal stage maintains a first withdrawal temperature. At least a part of the black liquor is led to a heat exchanger. An exchange of heat takes place in the heat exchanger between the black liquor and a bleaching filtrate that has been obtained from the bleaching plant. The exchange of heat results in the bleaching filtrate experiencing a raise in temperature of at least 5° C., after which the heated bleaching filtrate is used in the bleaching plant.

Abstract: The method and arrangement is for cleaning at least one of filter sheets and filter cakes in a pressurized white liquor filter with spray nozzles and driving fluid. The white liquor filter is used in a causticizing process in which green liquor is causticized before the white liquor filter by the addition of lime and in which it forms during the process a lime mud slurry. The white liquor filter 101 is used to separate white liquor from the lime mud. The driving fluid for the spray nozzle is constituted principally by the filtrate that is obtained from the filter.

Abstract: A device for positioning a drain pipe (6) of a draining system in a drying cylinder (1) the jacket (2) of which has inner circumferential grooves (3) for condensate which is formed as a result of heat transfer, said draining system comprising an outlet means and a plurality of drain pipes which are connected to the outlet means, wherein the draining system removes the condensate from the grooves via the drain pipes and the outlet means, wherein the device has a pipe positioner (40) which is disposed within an end portion (9) of the drain pipe located closest to the jacket, said pipe positioner comprising a supporting body (41) resting on the top surfaces (30) of two adjacent ridges (5), and a locking device (54) for fixing the drain pipe to the pipe positioner (40), which has a first through hole (48) for receiving the drain pipe (6), and a second hole (49) for receiving the locking device, said second hole opening into the first hole.

Abstract: A device for positioning a drain pipe (6) of a draining system in a drying cylinder (1), the jacket (2) of which has inner circumferential grooves (3) for condensate which is formed as a result of heat transfer, said draining system comprising an outlet means and a plurality of drain pipes which are connected to the outlet means, wherein the draining system removes the condensate from the grooves via the drain pipes and the outlet means, wherein the device has a pipe positioner (14) which is disposed in an end portion (12) of the drain pipe located closest to the outlet means, said pipe positioner comprising a mounting device (15) for mounting the drain pipe onto the outlet means, and a lockable connection (16) that connects the drain pipe to the mounting device (15). According to the invention, the lockable connection is a joint connection, which defines a fulcrum for pivoting of the drainpipe in a plane to enable positioning of the drain pipe relative to the bottom surface of the groove.

Abstract: The method is for influencing the flow from a strainer construction in a continuous digester. In order to avoid clogging of the withdrawal compartment in the strainer construction, an additive that counteracts precipitation processes is added directly to the withdrawal compartment while the cooking fluid is withdrawn from the withdrawal compartment. The addition of chemicals can take place at the same time as the withdrawn cooking fluid is withdrawn from the digester and the strainer construction, or while the withdrawn cooking fluid is fully or partially re-circulated back to the withdrawal compartment.

Abstract: The system is for the reception and transport of dry lime mud from a continuously operating pressurized filter in a causticization process. A tube valve is used as an outlet from the pressurized process. The tube valve has a minimum length that is twice a diameter of the tube. A column of lime mud can be held within it as a pressure lock. The column of lime mud can be caused to descend through the tube valve by controlling a difference in pressure between an inner surface and an outer surface of the tube such that the diameter of the tube expands essentially uniformly along its length by 5-10% or by at least 4-6 millimeters.

Abstract: A tissue papermaking machine is described, comprising a wet section and a press section comprising a single press with first and second press elements forming a press nip, and with a press felt running through the press nip in contact with the formed fiber web, whereby the second press element is arranged inside the loop of the press and felt, and a smooth belt runs through the press nip in contact with the formed fiber web, whereby the first press element is arranged inside the loop of the belt, and a transfer roll arranged inside the loop of the belt forming a transfer nip with a drying surface, whereby the smooth belt carries the fiber web between the press nip and the transfer nip. A pre-dewatering device is arranged upstream of the press to dewater the fiber web to a dry content of 15-30%. Associated methods are also provided.

Abstract: The high pressure sluice feeder has a conical rotor mounted in a housing having a complementary conical interior. The rotor has a plurality of trough-going pockets arranged offset to each other in the rotor. The housing has ports distributed evenly around a circumference of the housing and exposed to the pockets during rotation of the rotor. A conical exterior surface of the rotor or the conical interior surface of the housing is equipped with a flush-out groove. The groove catches any abrasive particles caught between the complementary conical surfaces of the rotor and housing. The abrasive particles are flushed out towards the trough-going pockets of the rotor when one end of the groove is pressurized by either one neighboring trough-going pocket or a sealing liquid supply to a gable end of the rotor/housing.

Abstract: The cyclone is for separating gas from a gas laden liquid stream by pressure reduction of the liquid stream. The cyclone has a cylindrical casing, having a tangentially directed inlet arrangement for the gas laden liquid stream, a lower outlet line for liquid and an upper outlet line for vapor and gas. The inlet arrangement is connected to a common supply source (BLPR), and has at least two insertion pipes. The flow in at least one of these insertion pipes is controlled by at least one valve that depends upon an order of flow from the common supply source to maintain a flow velocity above a critical value.

Abstract: Digested softened non-defibrated chips are fed out from a bottom of a digester. The chips are fed out under an influence of a bottom scraper at the bottom of the digester and through an outlet tap at the bottom of the digester and onwards to an outlet line connected to the outlet tap. This takes place before the softened chips pass through a blow-valve arranged in the outlet line, across which blow-valve a pressure drop of at least 0.5 bar and at most 3-5 bar has been established. The chips are exposed to a displacement wash after the chips have passed the outlet tap. The displacement wash has been established in the flow of chips through the outlet line before the chips are defibrated by the pressure drop across the blow-valve.

Abstract: The method and an arrangement are for the improvement of a wash after completed digestion in a continuous digester for the production of cellulose pulp. The softened chips are exposed to a radially directed displacement wash after they have passed the rotating bottom scraper. The displacement wash has been established in the flow of digested softened chips through the outlet tap before the softened chips are defibrated by the fall in pressure across the blow-valve that is arranged after the digester.