Abstract: A Pulp Mill Recovery installation for producing liquors containing different concentrations of recovered process chemicals or combustion gasses containing different concentrations of process chemicals from a spent liquor obtained from the production of pulp.

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: 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.

Abstract: A blade guide for a dual-frame wood chip sorter comprising a plurality of fingers having a slot therethrough to receive therein a blade, first and second mounting plates on each frame mounting thereon the bottom of a respective number of the fingers. At least one blade on the first frame is disposed intermediate adjacent fingers attached to a first mounting plate with each finger holding an intermediate blade being on another first mounting plate that is longitudinally separated from the other first plate on the frame. The pattern repeats for the second mounting plates with blades from the second frame.

Abstract: A method of preparing a digesting liquor having high sulphidity from a spent liquor obtained from digesting cellulosic fiber material, optionally without a conventional causticizing step is provided. Thermal decomposition of the spent liquor is conducted under reducing conditions in a reactor at a pressure of from atmospheric pressure up to about 150 bar and at a temperature of about 500.degree. to 1600.degree. C. so that a combustible gas phase containing hydrogen sulphide is formed in the reactor and extracted therefrom, and a phase of solid or molten material of substantially sodium sulphide or potassium sulphide, or mixtures thereof. The solid or molten material is dissolved in an aqueous liquid to produce said digesting liquor. The invention hydrogen sulphide is recovered from the gas phase and returned to the reactor to be present during the thermal decomposition of the spent liquor.

Abstract: A tensioning member for a blade screen that permits simultaneous tensioning of a plurality of blades in a blade screen, such as for wood chip sorting. The blades may be provided with a sawtooth detail on a bottom edge to reduce the build-up of wood ribbons or fines that would otherwise occur. An elastomeric joint is also provided which allows a dual-frame blade screen to be assembled, while compensating for any phase angle error between eccentric shafts provided to agitate the wood chips by moving the screens.

Abstract: This invention relates to a device for thermal decomposition of stock, especially a spent liquor obtained from pulp manufacture, where the gas stream formed in this connection passes through a liquid bath. The decomposition device has a reactor with a chamber in which thermal decomposition takes place, and a separation zone including a liquid bath for separating off components contained in the gas stream leaving the chamber. The separation zone includes a housing for the liquid bath and a tipping chute arranged adjacent the outlet of the chamber, so that the tipping chute at least partially increases in cross-sectional area in the direction of flow of the gas stream.

Abstract: A method and reactor for thermally decomposing a carbonaceous raw material (6) to recover gas and, if applicable, solid or liquid chemicals, the raw material being fed into a chamber (2) for gasification under under-stoichiometric conditions, the gasification is carried out in a gasification zone (15) at a pressure from atmospheric pressure up to about 150 bar and at a temperature within the range 500.degree.-1600.degree. C. According to the invention a part of the thermal energy required to maintain the endothermic reactions in the gasification zone (15) is produced by combustion of a fuel (8) in a combustion zone (16) located close to and in gaseous contact with the gasification zone, the raw material and fuel being supplied through different nozzle channels (12 and 13, respectively). An oxygen-containing gas (17) is supplied in an amount sufficient to oxidize substantially all the fuel.

Abstract: A method of recovering energy and chemicals from a spent liquor which, after thickening to a dry content of 50-90%, is fed into a reaction chamber (1) in which a plurality of temperature zones are maintained, said method comprising the steps of (a) converting the liquid phase in the spent liquor to a steam phase, (b) thermally decomposing the spent liquor to form gaseous organic substances and solid and/or molten organic and inorganic substances, (c) reducing and (d) oxidizing said substances produced during the thermal decomposition, oxygen or oxygen-containing gas being supplied to the reaction chamber (1) in a controlled amount in order to maintain the reactions, which comprise combustion of organic substances, and a bed of said solid and/or molten substances being formed in a lower temperature zone in the reaction chamber (1). According to the invention said steps are carried out during exposure to low frequency sound.

Abstract: A reactor for gasification of cellulose-waste liquors, especially black liquor. The reactor includes a reactor cladding a supply for liquor and combustion air in the upper part of the reactor, an outlet opening for gases and other material in the lower part, and a heat-insulating lining at the cladding and bottom part. The lining is arranged at a distance from the surrounding wall, thereby forming a gap for gas or air having a pressure exceeding that in the hearth of the reactor.

Abstract: A tensioning member for a blade screen that permits simultaneous tensioning of a plurality of blades in a blade screen, such as for wood chip sorting, is shown. The blade screen tensioning member includes a hinged bracket that may be supported on a portion of a frame, a spring steel blade holder for engaging a press-snap inserted into a hole in each of the engaged blades, and an elastic stop nut and stud for tightening and tensioning the blades. The blades are held in place at the opposite end of the frame by a similar holder, which, however, is fixed rather than hinged. The spring steel blade holder is reinforced for additional strength, and is bent at an approximately 45 degree angle where the press-snap is engaged. The blades themselves may also be provided with a sawtooth detail on a bottom edge to reduce the build-up of wood ribbons or fines that would otherwise occur. A sliding bearing with a dovetail configuration is also provided.

Abstract: A process and reactor for recovering energy and chemicals from spent liquor obtained in pulp production by thermal decomposing the spent liquor are described, said decomposing being carried out in a reactor at a pressure of from atmospheric pressure up to 150 bar and at a temperature of 500.degree.-1500.degree. C. so that a gas and solid and/or molten inorganic material are formed, said gas being rich in energy to be used as fuel or being useful as raw material for chemical production. According to the invention the thermal decomposition of the spent liquor is carried out during exposure to low frequency sound and without or with simultaneously supply of oxygen or a gas containing oxygen in an amount below that stoichiometrically required for complete oxidation of the substances formed at the thermal decomposition. The reactor comprises at least one sound generator arranged to generate low frequency sound in the reactor.

Abstract: A refiner for producing mechanical pulp has greater spacing between bars of the refiner grinding elements than is conventional. The grooves between the bars have a sloping bottom, making an angle of about 1.degree.-30.degree. (preferably 5.degree.-20.degree.) with respect to a straight line between the bars. The width of the grooves is about 10-50 mm. The relative rotation of the refiner elements (whether disks, cylindrical, or conical) with respect to each other results in sequential refining: a moving tension field, with successive compressions before impacts, and expansions, achieving increased fiber flexibility, more fiber rolling motion, and less fiber cutting. Pulp produced has increased fiber flexibility yet maintains a high content of long fibers, and higher refiner capacity also ensues. Also, the refiner of the invention can be used to mix treatment chemicals --such as bleaching chemicals in liquid form--into kraft pulp at high consistency (e.g. about 30-55%).

Abstract: A refiner for producing mechanical pulp has greater spacing between bars of the refiner grinding elements than is conventional. The grooves between the bars have a sloping bottom, making an angle of about 1.degree.-30.degree. (preferably 5.degree.-20.degree.) with respect to a straight line between the bars. The width of the grooves is about 10-50 mm. The relative rotation of the refiner elements (whether disks, cylindrical, or conical) with respect to each other results in sequential refining: a moving tension field, with successive compressions before impacts, and expansions, achieving increased fiber flexibility, more fiber rolling motion, and less fiber cutting. Pulp produced has increased fiber flexibility yet maintains a high content of long fibers, and higher refiner capacity also ensues. Also, the refiner of the invention can be used to mix treatment chemicals--such as bleaching chemicals in liquid form--into kraft pulp at high consistency (e.g. about 30-55%).

Abstract: Mechanical cellulosic fibrous material pulp (mechanical pulp to produce paper products) having lower freeness, and enhanced light scattering properties, tensile and tear strengths, for a given energy input, is produced by force feeding a refiner. Using a progressive compacting plugscrew, cellulosic material (e.g. wood chips) is fed to the refiner inlet at a rate greater than the transporting capacity of the refiner (e.g. about 10-40% greater). The refiner preferably is a low frequency conical refiner with steam removal at the grinding area between the conical refiner elements. The production rate is regulated by sensing the axial force on the refiner rotor and controlling the spacing between the refiner elements in response to the sensed axial force. The screw has a compaction ratio of at least 3/1 for wood chips and 6/1 for pulp, and is rotated at about 6-10% the speed of rotation of the refiner rotor.

Abstract: In the production of mechanical pulp, a refiner (defibrator) is driven by a steam turnine. The steam supply for the turbine comprises process steam generated in the refiner during the refining action, which steam is preferably passed through a reboiler. Some make-up energy is necessary to provide all of the power for driving the refiner, the make-up energy being preferably provided by clean steam from an accessory source introduced to the turbine by a steam ejector. A portion of the process steam, and the steam discharge from the turbine, can be used for presteaming the chips (comminuted cellulosic fibrous material) before introduction into the refiner. Any condensate from the turbine may be fed to the reboiler. Reduction gears are provided between the turbine and the refiner drive shaft so that the refiner is driven at optimum rpm for the particular material being treated.

Abstract: A device for dressing a regulating wheel in a centerless grinding machine is adjustable for adapting the shape of the envelope surface of the regulating wheel to work pieces of different diameters. For this purpose, the dressing point (3) is arranged in a support (4) which co-operates with a follower (12) which is movable along a forming bar (9). The surface (11) on the forming bar which contacts the follower can be given a variable curve by the fact that the forming bar is provided with means (16, 20) for achieving elastic deformation of the forming bar in a plane coinciding with the path of the follower (12).

Abstract: A method for manufacturing retortable cans is taught which includes the step of cable extruding a tube of plastic. Subsequently, a substantially gas-tight material is laminated to the outside of the tube and a plastic layer is laminated to the layer of substantially gas-tight material. Preferably, the gas-tight material comprises a metallic foil.

Abstract: An opening device is taught for packages comprising a substantially rigid outer wall portion and an inner layer of substantially gas-tight material (preferably a metallic foil), wherein the outer wall portion includes a first tearing notch defining an opening and a second tearing notch defining a grip tongue. The outer wall and the inner wall being interconnected substantially over their total surfaces facing each other with said outer wall portion and said inner layer being separated within an area substantially under said grip tongue. Preferably, the grip tongue is located completely within the opening defined by said first tearing notch.

Abstract: A fluid restrictor for a bearing pocket in a hydrostatic bearing. The bearing comprises a first member having a bearing pocket and a second member confronting and facing the bearing pocket and a channel in the first member for supplying a pressure medium. The channel is preferably located centrally of the pocket in the first bearing member. The outlet of the channel in the bearing pocket is surrounded by a projection having a part which is parallel to the bearing surface of the other member. The projection and bearing surface define a slot-like restrictor wherein the position of the part may be adjusted depthwise in the bearing pocket whereby the pressure in the pocket may be selectively regulated.