Abstract: A debarking mechanism including a number of rotatable debarking shafts extending parallel to an advancing direction (A) of the trees to be fed therethrough, which are provided with a number of teeth extending beyond the circumferential surface of the shaft and the debarking shafts being adapted to each other in such a way that the presently processed trees make a circular motion (C) in the debarking mechanism, in which motion the trees are forced upon the support surface constituted by the debarking shafts effected by the rotary motion of the debarking shafts. The uppermost debarking shaft has been fitted together with a guiding surface, the surface together with the uppermost debarking shaft forming a slot convergent in the direction of rotation of the debarking shaft.

Abstract: Method and system for controlling the operation of a recovery boiler or another boiler having a furnace wherein the operation is monitored by monitoring sensors, the sensors converting the acquired electromagnetic radiation to electrical signals which are conducted to image processing which forms an image of an object, such as the char bed and/or the char and/or chemicals on the furnace walls and/or deposits on boiler surfaces, based on the data from the sensors, and wherein the operation, such as burning of the char bed and/or the formation of char and/or chemicals on the furnace walls and/or the formation of deposits on boiler surfaces, is controlled with help of the image, wherein the sensors are arranged to produce sensor signals for 3D (three-dimensional) imaging, wherein the sensor signals are conducted to the image processing unit for forming a 3D image, such as an image of the bed and/or the char and/or the chemicals, and/or its shape describing derivatives, and/or temperature chart of the bed surface

Abstract: An apparatus for screening a fibrous suspension including: a housing, conduits therein at least for fiber suspension being fed, reject and accept, and a rotor and a cylindrical screen drum installed in the housing, at least one of which is rotatable, whereby a surface of the rotor is provided with rotor elements in proximity to the surface of the screen drum, whereby each rotor element includes a front surface facing a flow of the fiber suspension, an upper surface and a trailing surface sloping from the upper surface towards the surface of the rotor, wherein the trailing surface of the rotor element is curved and sidewalls of the trailing surface converge at a back point of the rotor element.

Abstract: An apparatus for distributing a pulp flow, said apparatus including: a valve body connected to an inlet conduit and an outlet conduit for the pulp flow and provided with a closing member for opening and closing the valve to regulate the pulp flow; a distribution member arranged in a direction the pulp flow and downstream of the closing member, said distribution member distributing the pulp flow into at least two partial flows, and at least two channels wherein each channel receives a respective one of the two partial flows, wherein said channels are connected to the valve body or to the outlet conduit from the valve.

Abstract: The present invention relates to a method in connection with smelt removal form a recovery boiler, whereby the smelt is removed from the boiler via a smelt spout surrounded outside the boiler by a hood and a dispersion medium, preferably steam, is fed into the smelt flow falling from the smelt spout for shattering the smelt flow. An essential characteristic is that at least one wall of the hood is washed with liquid so that the liquid first flows downwards on the outer surface of the hood wall and is led into the interior of the hood via at least one trough-like member arranged on the outer surface of the wall and openings in the wall so that the liquid further flows downwards on the inner surface of the wall. The invention also relates to an arrangement for washing the hood and the feeding device for the dispersion medium.

Abstract: In a boiler, a space is reserved to expand the boiler by increasing the front and rear walls. To expand the boiler, wall additions are added to increase the width of the front and rear walls. After the expansion, the distance between the front and rear walls is substantially the same distance between the front and rear walls before the expansion.

Abstract: An arrangement in screening apparatuses of the pulp and paper industry, including a conduit for removing reject formed in a screening process. The circulation of material is arranged between the reject removal conduit and the interior of the screening apparatus from the removal conduit into the interior of the screening apparatus via a conduit external to the screening apparatus. When such a by-pass flow is arranged for pulp via external circulation, heavy particles in the layer being diluted are allowed to be separated onto the bottom of the reject removal conduit and therethrough e.g. into a separate junk trap.

Abstract: An apparatus for cleaning and cooling a liquor nozzle, the nozzle including at least a liquor tube for feeding liquor and chemicals into a furnace of a recovery boiler. The apparatus includes an outer casing tube, which defines a space whereto conduits are provided for introducing water and steam to generate an emulsion or a conduit for introducing emulsion generated by the water and steam and the surface of which is provided with openings, such as pores or holes, for discharging the emulsion formed by water and steam through the outer casing.

Abstract: A method for burning chlorine-containing liquors in a chemical recovery boiler at a pulp mill, wherein the recovery boiler includes spent liquor sprayers for feeding spent liquor and a number of combustion air levels including: increasing a combustion temperature in the recovery boiler in a burning zone where a chlorine-containing liquor or a chlorine-containing effluent is burned; while burning the liquor or effluent, volatilizing the chlorine in the liquor or effluent to produce chloride-containing salts in flue gases in the boiler, and removing the chloride-containing salts from the flue gases.

Abstract: An apparatus for treating pulp including: at least one liquid-permeable surface rotating around a shaft, onto which surface a pulp layer is formed; a feeder to feed pulp to the apparatus for treatment on the liquid-permeable surface; an internal barrier defining a first pulp treatment section and a second pulp treatment section; the first treatment section receiving from the feeder a first type of pulp and the second treatment section receiving from the feeder a second type of pulp, wherein the first type of pulp is supplied to the feeder from a first pulp treatment stage in a pulping system and the second type of pulp is supplied to the feeder from a second pulp treatment stage in the pulping system, and a pulp discharge to discharge treated pulp from the apparatus, wherein the pulp discharge discharges the first type of pulp after treatment separately from discharging the second type of pulp after treatment, and a filtrate discharge to discharge filtrate flowing through the liquid-permeable from the apparat

Abstract: The present invention relates to a method of treating lime mud slurry being generated in a causticizing process in a pulp mill in a disc filter, in which method the lime mud is fed in the filter, thickened on the filter discs and removed from the filter discs. The lime mud is treated in at least two stages in one and the same disc filter in such a way that the lime mud slurry entering the filter is fed onto only a part of the filter discs, on which lime mud is thickened and removed from the discs, and the removed lime mud is re-slurried in liquid, and the lime mud slurry thus obtained is fed onto a second part of the filter discs, on which lime mud is thickened and removed from the filter and led into a subsequent process stage. The invention also relates to an apparatus.

Abstract: The invention relates to an apparatus for sorting wood chips, said apparatus having a feeder for supplying the wood chips onto a sloping support surface so that the chips slide along the support surface and over a slit extending across the support surface. A flow of gas through the slit providing an impulse action to the chips as the chips pass over the slit. Alongside the impulse-action generating gas flow discharging from the slit is mounted a baffle/guide plate for controlling turbulence created by the gas flow.

Abstract: A log shuffler and conveyor assembly including: a chute including a log conveyor having a bottom surface and at least one sidewall; a gap in the log conveyor, and a log shuffler arranged in the gap of the conveyor, wherein the shuffler includes at least one pivoting plate having a first edge moving reciprocally above and below the bottom surface of the chute.

Abstract: A method of treating pulp in connection with the bleaching of chemical pulp, said method including treating of the pulp in at least an ozone, chlorine dioxide or alkali phase and thereafter washing of the pulp in a washing device having an E10 value of at least 3, whereby washing liquid is introduced into the washing device countercurrently in relation to the pulp and filtrate is discharged from the washing device. At first the pulp is washed in the washing device so that the washing liquid is filtrate obtained from the washing device itself and the amount of thus circulated washing liquid is 1.5-3.5 t/adt pulp, whereafter the pulp is washed with liquid introduced from outside the washing device, the amount of said liquid being such that the dilution factor in the latter wash is less than 1 t/adt and that the total amount of washing liquid used in the washing device is such that the dilution factor is more than 0 t/adt.

Abstract: The present invention relates to a method for reducing nitrogen oxide emissions in combustion. Fuel is combusted in a first zone, whereby nitrogen oxides are generated. Supplementary fuel is fed in another zone under reducing conditions. At the same time, the temperature is adjusted so that nitrogen oxides convert essentially to hydrogen cyanide. Finally, air is fed in for finalizing the combustion and converting the hydrogen cyanide into nitrogen.

Abstract: The invention relates to a chipper (1) bed knife (2) attached detachably to the chipper frame (3), the chipper (1) having a chipper disc (5) supported on its shaft (4), which shaft is fitted rotatably to the chipper frame (3), the chipper disc (5) comprising a number of knives (6) arranged to pass the knife edge (7) of the bed knife (2) at a distance corresponding to the required knife clearance (v), when the chipper disc (5) is rotating. The bed knife (2) also has a second knife edge (7?), the said knife edges (7, 7?) being arranged at a distance from each other in the direction of movement (A) of the chipper disc (5) knives (6). A groove (8) is formed in the bed knife (2) between the said knife edges (7, 7?).

Abstract: A method for feeding lime mud into a lime kiln including a rotary kiln shell having an interior between a first end wall and a second end wall, the method including: feeding the lime mud into a flue gas flow in the interior of the rotary kiln shell or in close proximity to the shell to pretreat the lime mud; separating the pretreated lime mud from the flue gas flow; conveying the separated lime mud into the lime kiln, and calcining the separated lime mud in the lime kiln.

Abstract: An arrangement is disclosed for supplying an air jet form to the furnace of a recovery boiler, where the furnace has a front wall, a rear wall and side walls. Black liquor spraying devices are disposed on the furnace walls at one or several levels of the furnace. A plurality of air ports are located at several horizontal levels for introducing air into the furnace from an air supply. In the arrangement for the secondary air flows, two horizontal air levels at different elevations are arranged above the lower primary levels and below the black liquor sprayer. Secondary air is supplied from two opposite walls and the air ports from each of the two levels are located so that the air jets are introduced in an interlaced pattern having an even number of jets on one opposite wall and an uneven number of jets on the other opposite wall. The air jets of said at least two air levels are located substantially one above each other in substantially vertical rows.

Abstract: A debarking mechanism for the excortication or pretreatment of trees for separately performed final barking and for the expulsion of at least some of the removed barks from a wood flow passing through the debarking mechanism, the debarking mechanism including a number of rotatable debarking shafts extending parallel to an advancing direction (A) of the trees to be fed therethrough, which are provided with a number of teeth extending beyond the circumferential surface of the shaft and adapted to strip bark off the presently processed trees transversely to the lengthwise direction of the trees and at the same time to convey the trees transversely relative to said shafts, and the shafts together with the teeth thereof, being adapted to constitute at least a section of a support surface, upon which the presently processed trees travel through the debarking mechanism, and the debarking shafts being adapted to each other in such a way that the presently processed trees make a circular motion (C) in the debarking me

Abstract: A filter element for pulp screens comprising at least two plates separated by a distance from each other, wherein one plate has a number of projections formed thereon, and the projections being directed towards the other plate. The plates are attached to each other at the projections.