Abstract: Refiner disc segments for use in connection with disc refiners are disclosed. The refiner disc segments include in a radial portion thereof raised bars extending outwardly from the center of the segment with grooves defined between the raised bars, the raised bars having a width B, and the grooves having a width S and a depth D such that the ratio B.multidot.S.multidot.D/S+D is greater than about 2.7 mm and less than about 4.3 mm, and wherein the width B is from about 1 to 4 mm, the width S is from about 2 to 5 mm, and the depth D is from about 1 to 7 mm. Overall refining apparatus including a pair of refining members which includes such refining disc segments are also disclosed as is a method for producing these refining disc segments.

Abstract: A method is disclosed for delignification of ligno-cellulose containing fiber material comprising mixing an oxygen-containing gas with the cellulose fiber material so as to atomize the gas and form a foam of the gas and the cellulose fiber material, and without an intervening oxidation step, subjecting the foam to upwardly flowing, substantially non-pressurized, alkali extraction. The alkali extraction step is conducted at a temperature of from about 40.degree. to about 80.degree. C. and at a pH, ligno cellulose containing fiber concentration and oxygen containing gas concentration sufficient to provide a bleached, delignified cellulose fiber without bleaching the lignin substance extracted from the material and to suppress lignin condensation reaction during the extraction.

Abstract: Lignocellulose material is pretreated with steam, heat, lignin softening chemicals or combinations thereof. The pretreated material is then refined in a disc refiner. Water is added to the material in the refining zone of the disc refiner to form a suspension at concentration of 8-15% at the point of discharge from the gap between the discs of the refiner. Steam development and steam backflow from the gap is reduced.

Abstract: A treatment for wood chips in the manufacture of pulp is described. Prior to chip washing, the chips are placed in contact with an impregnation liquid such that all readily fillable cavities in the chips become filled with the liquid. The chips can be steamed prior to the impregnation process to increase the liquid absorption. After the impregnated chips are drained of the excess liquid, no appreciable amount of washing liquid is absorbed by them during a subsequent washing cycle used to remove included gravel and sand.

Abstract: The digestion of the cellulose-containing material is performed with a digestion liquor containing sulphur and sodium followed by recovery and regeneration of said digestion liquor and bleaching of the cellulose-containing material with chlorine dioxide. The SO.sub.2 -containing and possibly chloride-containing gas from the recovery boiler (11) of the process and from combustion of evil-smelling gases (20) is absorbed in an absorption liquor containing and alkali metal salt solution free of sulphur or sulphur compounds such as sulphide or thiosulphate, in a scrubber (27). The resulting scrubber liquor is mixed with acid residual solution (26) from the manufacture of chlorine dioxide, whereby sulphur dioxide (32) in gaseous state is returned to the process, whereafter the residual solution (34) free from SO.sub.

Abstract: Disclosed herein are apparatus and method for measuring, during operation, the degree of sharpness of grindstones in a wood pulp grinding machine of the type where one motor drives two grindstones, each having two or more pockets for loading timber. In accordance with the apparatus and method, the power of the motor and the feed rates of the pockets are simultaneously measured. After a predetermined time interval, during which the operating conditions of the machine change, these measurements are made again. The degree of sharpness of the grindstones can then be calculated using the measured values of power and feed rates.

Abstract: An absorbent cellulose material is disclosed which comprises a substituted cellulose having an average degree of substitution sufficiently low to render the material insoluble and in which the fibers have an increased surface area formed by bursting the fibers during drying. In addition, a method of manufacturing such absorbent material is also disclosed which comprises providing an insoluble substituted cellulose material having an average degree of substitution sufficiently low to render the material insoluble, swelling the material to its maximum swelled state, fixing the material in that state, and drying the material while maintaining the material in its swelled state to thereby prevent shrinkage of the material during drying and to cause the fibers to burst during drying.

Abstract: A method and apparatus are disclosed for compressing a portion of low pressure steam into steam of higher pressure in which the means for doing so are energized by the heat energy of the remainder of the low pressure steam.

Abstract: Method and apparatus for refining fiberous material in a disc refiner for withdrawing steam developed during refining of such fiberous material. The disc refinger comprises a pair of refining discs each of which includes a inner refining surface. The refining discs are mounted for rotation relative to one another in a housing with the refining surfaces opposing one another during the relative rotation and defining a refining space therebetween. Each of the refining surfaces of the refining discs is provided with a passageway for withdrawing steam developed in the refining space. The passageways extend from the respective refining surfaces in a direction away from the refining space and radially inward relative to the direction that the fiberous material moves through the refining space.

Abstract: Apparatus for drying web materials is disclosed, including a drum, means for supplying steam under pressure to the interior of the drum, passage means extending axially in a portion of the outer drum wall and through one of its end walls for removing condensed steam formed within the drum therefrom, groove means extending circumferentially around the inner surface of the cylindrical drum for collecting condensed steam and supplying it to the passage means, throttle means outside of the end wall, vacuum condensing means under reduced pressures for condensing steam carried by the condensate, and discharge conduit means connecting the throttle means to the vacuum condensing means, the throttle means being adapted to provide a pressure drop between the passage means and the discharge conduit.

Abstract: A method for improving the homogeneity of ligno-cellulose containing materials during digestion in a digester is disclosed. Specifically, the ligno-cellulose containing material and cooking liquor are charged to the digester, a portion of the cooking liquor is drawn off from the digester and heated, preferably in a calorisator, and the heated liquor is divided into two portions, the first portion being returned to the top of the digester, and the second portion being returned to the bottom of the digester, and boiling is caused to occur in the digester solely by terminating the flow of liquor into the top of the digester.

Abstract: A device is provided for applying a fluid surface treatment agent to a paper web that includes a container for receiving the fluid surface treatment agent to be applied. The container includes a gap which is mounted for contact with the paper web for transferring the fluid from the container to the paper web. A rotary brush is positioned opposite the gap and on the other side of the paper web, and includes fluffy surfaces for applying pressure to the paper web to press the paper web into contact with the fluid applying gap. The position and pressure of the brush are adjustable, and a casing is provided to at least partially surround the brush to produce a fan effect on the paper web as the brush rotates relative thereto.

Abstract: A method is provided for controlling the amount of active substance applied to the surface of a continuously-moving paper web, with the active substance being dissolved in or dispersed in a treating liquid. The paper web is passed over a coating unit and includes an opening through which the treating liquid is applied to the paper web. The method includes the steps of supplying a first fluid with a predetermined amount of active substance to a first batching device and supplying a second fluid consisting of pure solvent or dispersing agent to a second batching device. The output of the first batching device is controlled in response to the speed of the paper web to control the amount of active substance supplied to a mixer, and the output of the second batching device is controlled in response to the fluid pressure at the opening of the coating unit to control the amount of solvent or dispersing agent supplied to the mixer.

Abstract: Refining elements for use in the refining of fibrous materials, such as cellulose pulps and the like, are disclosed. Specifically, the refining elements disclosed comprise a pair of refining zones disposed in a direction of flow of the fibrous materials through the refining element, both refining zones including both grooves and ridges on the face thereof, and specifically wherein the ratio of the width of the grooves to the width of the ridges in the first refining zone is greater than the ratio of the width of the grooves to the width of the ridges in the second refining zone. Preferably, the number of ridges in the second refining zone is less than that in the first refining zone, and at least three such refining zones may also be included in the refining element.

Abstract: Raw fibrous material is preheated in a preheater in the presence of steam under a pressure greater than atmospheric pressure and then continuously introduced into a disc refiner, without prior defibration, whereby steam is generated in said disc refiner. The generated steam is continuously conducted away from said disc refiner as subsequent fibrous material is continuously being introduced into the disc refiner in order to obtain a pressure in the disc refiner which is greater than atmospheric pressure but less than the pressure in said preheater.

Abstract: A load-weighing device for indicating the weight of a load is provided for attachment to the load-carrying member of a lifting device. The load-weighing device includes a frame connected to the load-carrying member and a bearing block mounted in the frame for rotation relative to the load-carrying member. A clearance space is provided between the lower surface of the bearing block and the frame which is eliminated upon the application of a load. A bearing member is also mounted in the frame and includes a cylindrically-shaped lower surface which is arranged to abut a cylindrically-shaped upper surface of the bearing block. The bearing member is provided with a recess for receiving a pressure-sensitive member so that when a load is lifted by the load-carrying member, the force of the load is transferred to the pressure-sensitive member which operates to provide a load-measuring value to a receiver.

Abstract: A method for the treatment of the surface of refining elements or segments is disclosed. The refining segment surfaces, which generally include grooves and ridges, are normally subjected to mechanical polishing or grinding prior to use, thereby smoothing the surface of the ridges of the refining segments and depositing a surface layer of material thereon. This surface layer is removed according to the invention disclosed, by either mechanical or chemical means, in order to permit the uniform wear of the ridges during use, and to roughen that surface. This may be accomplished chemically, for example, by such processes as electrolysis and etching with various acids.

Abstract: Apparatus for refining fibrous material which includes two oppositely rotating refining discs each supported on a shaft, which shafts are rotatably mounted on a base. Bearing means are provided for the shafts which are adapted to receive the axial forces applied to the shafts during the refining operation. The bearing means includes at least two axial bearings on each shaft and a piston and cylinder arrangement on each shaft connected to the base for transferring the axial forces from the axial bearings to the base.

Abstract: An improved fuse size, as well as a method for preparing same, are disclosed. Specifically, the fuse size disclosed includes a combination of urea and carboxymethyl cellulose, preferably including added starch. The method disclosed includes combining the urea and carboxymethyl cellulose, heating the mixture, and then adding an oxidizing agent to the mixture in the presence of a metal ion which has at least two oxidation stages, but which is in the lower of said oxidation stages when added thereto. In a preferred embodiment, the oxidizing agent employed comprises hydrogen peroxide, and the metal ion is preferably bivalent iron, added in the form of a ferrous salt such as ferrous chloride.