Abstract: A process for purification treatment of an impure liquid, such as a contaminated condensate, obtained when producing paper or paper pulp. The liquid is introduced intro a stripper device at an admission point (C) and the stripper device is also supplied with an acidifier preferably at a point (D) that is located above the admission point (C) and malodorous gases are driven off from the stripper device.

Abstract: The invention relates to a throttle device for delivery of a current of gas through a channel (1), the device comprising a flap (4) which is arranged so that it can pivot on an axle (5) and which is designed in such a way that, at a certain pressure force exerted by the current of gas, it is opened from a position in which the channel (1) is essentially closed. The invention is characterized in that it comprises at least one weight (7) which is arranged to rotate together with the flap (4) and is designed to deliver a torque to the axle (5) in conjunction with the pivoting of the flap (4). The invention is intended in particular for recovery boilers, or heating boilers or steam boilers for solid fuels. The invention achieves an improved air penetration in respect of air flowing into the boiler.

Abstract: Provided is a process for making pulp having the steps of:contacting an undigested cellulosic fiber material with a pretreatment liquid formulated from a mixture comprising alkali metal bicarbonate and alkali metal hydrogen sulfide as reaction components which are dissolved or disbursed in an aqueous liquid, under conditions that:(1) the reaction components react to form H.sub.2 S, CO.sup.2 and alkali metal carbonate in situ;(2) HS.sup.- ions are formed by disassociation of H.sub.2 S and/or by disassociation of alkali metal hydrogen sulfide; and(3) at least a portion of the H.sub.2 S and/or HS.sup.- ions is absorbed or diffused into the undigested cellulosicfiber material to enhance the sulfur content of the undigested cellulosic fiber material,to form a sulfur enhanced, undigested cellulosic fiber material, wherein the pretreatment liquid is substantially free of alkali metal hydroxide; anddigesting the sulfur enhanced, undigested cellulosic fiber material in a digester to form a pulp.

Abstract: A filtering apparatus comprises: a pressure vessel; a plurality of filter elements arranged within the pressure vessel, the filter elements each having an upper end, a lower end and a side wall; filling bodies positioned within the filter elements; a first conduit for introducing compressed gas into the pressure vessel; a second conduit for transporting unfiltered liquid to and from the pressure vessel; and a third conduit for removing filtrate from the pressure vessel and transporting back-flushing liquid to and from the filter elements, the third conduit positioned proximate to a bottom portion of the pressure vessel and attached to the lower ends of the filter elements, such that the third conduit provides a support structure for the filter elements and the back-flushing liquid introduced via the third conduit fills the filter elements in a direction from the lower ends toward the upper ends, the volume of back-flushing liquid introduced into the filter elements limited by the filling bodies.

Abstract: Arrangement for separating off undesired particles from a suspension stream. The arrangement has a closed housing with an inlet for the suspension from which particles are to be separated off, an outlet for the treated suspension and an outlet for undesired particles. The arrangement also includes a screening drum that is perforated by a number of circular slits and cleaning members that are disposed inside the housing. The screening drum is immovable and the cleaning members are arranged to rotate along a circumferential surface of the screening drum and down into the circular slits.

Abstract: A grate assembly for a fluidized bed boiler is provided. A number of parallel sparge pipes extending substantially in the horizontal direction and are provided with devices for supplying fluidizing air from within sparge pipes into a combustion chamber located above the grate assembly. The discharge of coarse material is effected through an aperture system between the sparge pipes into a receiver unit fitted below the grate assembly. At least some of the sparge pipes are provided with a cool medium circulation, wherein at least a part of the cool medium circulation is placed in the sparge pipes at the upper edges thereof, to extend so that it provides a limit to the edge of the aperture system in the upper part of the sparge pipe in the longitudinal direction of the sparge pipe. Devices for supplying fluidizing air comprise a tubular supply channel that is directed from the upper surface of the sparge pipe. The supply channel is provided with air nozzle apertures at its upper part.

Abstract: Method for safely carrying out chemical reactions in a vessel having a discharge end, wherein a control valve is provided at the discharge end, and wherein reacted and unreacted chemicals are cleared from in front of the control valve thus reducing the risk of reacted and unreacted chemicals blocking the discharge end of the vessel.

Abstract: A device for filtering a liquid substance comprising a container (1) having an inlet (2), a rotor (6), an inner rotor part (7), at least one disc filter (8). Spray nozzles are provided for releasing material filtered away from the substance and deposited on the filter disc. Furthermore there are conveyors (17) for removing the material released.

Abstract: The process for the final evaporation has at least two evaporation appliances. These appliances are coupled in series with respect to the black liquor and in parallel with the live steam (primary steam), which drives the evaporation, and with the secondary steam that is generated by the evaporation. The pressure of the primary steam that is supplied to the appliance(s) where the liquor concentration is at the highest concentration is greater than the pressure of the primary steam supplied to the other appliances where the liquor concentration is not so high.

Abstract: The invention relates to a valve system for a space (1) which is under vacuum in relation to its surroundings (3), which valve system comprises a valve unit (7) which is intended to be arranged in association with a wall (2) which delimits the said space and has a wall opening (4) through the said wall, which valve unit comprises a valve (8) which is normally shut and closes the said wall opening but is arranged to be opened and allow air from the surroundings into the said space if the vacuum, i.e.

Abstract: A fractionator includes a shaft attached to a drum which is positioned in a housing and which is rotatable about a substantially horizontal axis and has an inlet means for suspension and at least two outlets for fractions. The drum has a first end and a second end and includes at least two fluid tight walls surrounding the axis. The drum also extends in its longitudinal direction between the first end and the second end to define a fluid channel. The fluid channel extrends substantially parallel to the axis from the first end to the second end and continuously in a circumferential direction of at least 360.degree..

Abstract: The present invention provides a method for continuously cooking kraft pulp in a digester having the steps of:feeding chips into an inlet of a digester;supplying black liquor to an impregnation zone of the digester in an amount such that the black liquor makes up greater than 40% by volume of the total volume of liquid present in the impregnation zone;extracting liquor from a screen girdle downstream of where the black liquor is added to the digester, in the direction the wood chips flow through the digester, in an amount greater than 50% by volume of the total volume of liquor present at the location of the screen girdle;maintaining a liquor:wood ratio in the impregnation zone of greater than 3:1; anddischarging cooked pulp from the digester.

Abstract: The present invention relates to a digester for continuous cooking, under elevated pressure and temperature, of fibre material in a vertical digester (1), where fibre material and cooking liquid are fed into the top of the digester, used cooking liquor is drawn off from at least one digester screen arrangement (1D) between the top and the bottom of the digester, and fibre material is fed out from the bottom of the digester, it being possible to maintain the temperature in the cooking zone immediately above the digester screen arrangement (1B) at essentially the same temperature level as the remaining cooking zone or cooking zones of the digester.

Abstract: Apparatus for adjusting the axial position of a rotatable feeder (2) in a charger for sluicing lignocellulose material and, if appropriate, liquid from a first space, with a first pressure, to a second space, with a different pressure, which apparatus (10) comprises an adjustment housing (11) connected immovably to the charger housing and an adjustment shaft (16) which moves the feeder in an axial direction. A worm wheel (23) is arranged on the adjustment shaft, and is coaxial with respect to the same, a shaft for a worm (27) extends through the adjustment housing wall, the worm (27) itself is in engagement with the worm wheel, turning members (29) are arranged to turn the worm and the worm wheel, conversion mechanisms (25, 26) are arranged for converting the rotational movement of the worm wheel, into an axial movement of the adjustment shaft and thus the feeder.

Abstract: The invention relates to a process for purifying electric precipitator ash of chlorides and potassium by means of leaching, filtering and washing a filter cake, with the leaching being carried out using water and recirculated filtrate from a previous washing. The process is characterized in that the filtration and the washing of the filter cake, and, where appropriate, the leaching, take place in a pressure filter in one and the same vessel.

Abstract: The present invention relates to a process and a device for the separation and purification of gas from a fiber suspension, especially residual gas after ozone delignification or pulp suspension, wherein the suspension together with the gas is introduced into a cyclone (2) or similar in which essential separation of suspension takes place, after which the essentially gas-free suspension is drawn off downwards and the gas (5) containing residual fiber and/or other impurities is drawn off upwards, the gas stream (5), before it is conducted away, being led through a liquid bath for separation of residual fibers and/or other impurities from the gas stream.

Abstract: Apparatus for treating pulp, comprising a stand (1); a rotatably mounted drum (3); feeding and discharging members (6, 8) for the pulp; a wall member (2) which surrounds the jacket (40) of the drum in order to delimit therebetween a material space (5) with which the feeding member communicates via an inlet (7), which material space includes two treatment zones (24, 25); a delivery member (26) for delivering liquid to the treatment space via the wall member; a press member (22, 23) arranged downstream of each delivery member in order to exert a press force against the pulp; a collecting chamber (18, 19) inside the drum in connection with each treatment zone and press member for receiving liquid which is pressed through the jacket. According to the invention, the drum is supported by two support rollers (12, 13) which extend through the drum on either side of its vertical center plane and are in contact with the inner side of the drum, the support rollers being rotatably mounted on the stand (1).

Abstract: A method and device for cooking pulp by increasing the effective alkali concentration in the residual phase of the cooking process to substantially improve the residual delignification rate and thus improving the pulp properties such as the pulp strength and pulp yield at a given lignin content.

Abstract: The invention relates to a method and arrangement for removing gas from a fibre/liquid suspension in a fibre treatment line in a pulp mill, which line includes at least one stage in which the fibre/liquid suspension is treated and/or stored in a large container (2) before being conveyed for further treatment. The fibre/liquid suspension is conveyed to the large container via a vessel (15) which with its lower part communicates with the large container and has a significantly smaller horizontal sectional area than the large container, but extends upwards above the level (4) of the fibre/liquid suspension in the large container, with gas being removed from the fibre/liquid suspension (19) in the area (18) of the upper part of the smaller vessel by means of the area being subjected to a subatmospheric pressure.

Abstract: The invention relates to a process for integrated evaporation and gasification of spent liquor from the production of cellulose, the gasification taking place in a reactor (1) at a pressure of from atmospheric pressure up to about 150 bar and at a temperature of about 500.degree.-1600.degree. C., by partial combustion of the spent liquor, a gas phase and a phase of solid and/or smelted material being formed in the reactor and being removed therefrom. The invention is characterized in that the combustion gas obtained from the reactor (1) by partial combustion of the spent liquor is brought together in direct contact with spent liquor, which may have been pre-evaporated, in a first stage--for example a venturi scrubber--, with alkali metal compounds, etc.