Abstract: In a cellulose pulp handling vessel having a first diameter material storing or treating portion above a second diameter discharge which is at least 20% less than the first diameter, reduced compression of the material and reduced power requirements of an agitator (if used), compared to prior art constructions are provided. A first transition, preferably a substantially smooth interior surface substantially frusto-conical transition, is provided between the first and second diameters. A second single-convergent transition may be provided above the first transition. A rotating agitator with at least two arms and associated paddles may be mounted for rotation in the transition about a substantially vertical axis for agitating the material in the transition. If desired, the transition may be moved, such as with a vibrator or oscillator. The invention is particularly suitable for pulp digesters and impregnation vessels.

Abstract: The invention relates to a former-press section (100, 110) of a paper machine and to a method of transferring a web from a former to a press section. Between the former section (100) and the press section (110) there is a pre-press zone (PP) which removes water from the web (W) and through which the web (W) is passed as a closed draw from the former section (100) to the press section (110). The upper wet wire (10) or the equivalent transfer wire (10A) of the former section (100) is passed through the pre-press zone (PP), the web (W) being passed on the lower face of said wire into and through the pre-press zone (PP). Inside the loop of the upper wet wire (10) or of the equivalent transfer wire (10A) and/or inside the loop of the lower wet wire (20) there are transfer devices (15, 15a, 16, 26) based on the use of a pressure difference.

Abstract: A binder is applied to particles which are then combined with fibers to bind the particles to the fibers. The particles have functional sites for forming a hydrogen bond or a coordinate covalent bond. The fibers have hydrogen bonding functional sites. The binder comprises binder molecules, the binder molecules having at least one functional group that is capable of forming a hydrogen bond or a coordinate covalent bond with the particles, and at least one functional group that is capable of forming a hydrogen bond with the fibers. A substantial portion of the particles that are adhered to the fibers may be adhered in particulate form by hydrogen bonds or coordinate covalent bonds to the binder, and the binder in turn may be adhered to the fibers by hydrogen bonds. Fibers containing particles bound by this method are easily densified.

Abstract: A system for removing bleed-through contaminants from OCC fiber pulp includes a plurality of primary flotation cells, with each primary flotation cell having an inlet, an accept outlet and a reject outlet. The inlet and the accept outlets of the plurality of primary flotation cells are coupled together in a series configuration. The reject outlets are coupled together in parallel. A secondary flotation cell has an inlet, at least one accept outlet and a reject outlet. The secondary flotation cell inlet is fluidly coupled with the reject outlet of the primary flotation cells. A water clarifier has an inlet, a clarified water outlet and a sludge outlet. The inlet is connected with the reject outlet of the secondary flotation cell.

Abstract: The process according to the present invention relates to the treatment of wastewater discharged from a bleach plant and more particularly treatment of bleach plant alkaline wash filtrate from treatment-steps and/or delignification/bleaching-steps of pulp. Further improvements of known processes are needed for solving the problems associated with the recovery of alkaline filtrates into the chemical recovery system. According to the process of the present invention, alkaline wash filtrate from treatment-steps and/or delignification/bleaching-steps of pulp is treated in a process by the following steps: i) treating at least a part of the alkaline filtrate in order to produce an alkaline concentrate enriched in high molecular weight dissolved organic compounds and a stream depleted in organic compounds, where the share of the alkaline concentrate to the total amount of the alkaline filtrate corresponds to a volume reduction factor (VRP) in the range of from about 2.0 up to about 7.

Abstract: The invention relates to a process for enhancing the concentration of the fiber derived dissolved and colloidal substances in process water that comes from mechanical pulping. According to the invention, process water is treated with enzyme preparations that have an effect on carbohydrates and that contain mannanase and/or endoglucanase, in particular, which break down the soluble carbohydrate polymers contained by the process water into low molecular weight oligosaccharides. The treatment prevents an increase in viscosity so that process water can be concentrated into a high dry content, or the treatment can be used to lower the viscosity of previously concentrated process water to facilitate after-treatment.

Abstract: Process and apparatus for degassing a flowing fibrous paper suspension. The process includes separating the suspension into partial streams, spraying the partial streams into a degassing chamber under vacuum, and exposing the suspension to the degassing vacuum for at least 10 seconds. In this manner, gas within the suspension is separated from the suspension. The process also includes suctioning the separated gas out of the degassing chamber. The apparatus includes a degassing chamber structured to subject the suspension to a vacuum sufficient for degassing, an element arranged at an inlet of said degassing chamber for dividing the suspension into a plurality of partial streams, and a suction device for removing separated gas from said degassing chamber. The apparatus is structured and arranged so that the suspension is subjected to the degassing vacuum for a duration of at least 10 seconds.

Abstract: The invention refers to a method for black liquor gasification in recovery boilers, of the type having a lower portion, referred to as a lower furnace and an upper portion, referred to as an upper furnace, black liquor sprayers for introduction of black liquor provided in the boiler above the lower furnace, and a number of combustion air levels, whereby the invention incorporates adding oxygen enriched air to the combustion air or directly into the lower furnace at at least one air level underneath the liquor sprayers for the purpose of creating the best possible reducing conditions in the lower furnace, redistributing from the lower furnace combustion air not needed therein following the addition of oxygen enriched air, thereby significantly reducing upward gas velocity underneath the black liquor sprayers, and introducing the redistributed combustion air in the upper furnace, thereby creating the reducing conditions and a controlled temperature in the lower furnace for emission control.

Abstract: The present invention is generally directed to a process for recycling paper containing wet strength additives. The process generally includes the step of mechanically fiberizing the paper in order to reduce the paper into substantially discreet fibers. The paper can be fiberized in various devices, including mills and pulverizers. Once the paper has been converted into substantially discreet fibers, the fibers can then be used in forming various paper products, including wipers and tissues. Of particular advantage, it has been discovered that fibers produced according to the process of the present invention produce paper webs having high bulk, high brightness, high porosity, and high opacity.

Abstract: There is provided a photocatalytic pulp composition characterized in that 40 to 95 wt % of a pulp and/or a paper having the water content of 3 wt % or less, the average fiber diameter of 5 to 300 &mgr;m and the average fiber length of 0.7 to 70 mm is blended with 5 to 60 wt % of titanium oxide. A photocatalytic pulp composition is provided in which 25 to 100 wt % of a thermoplastic resin is blended relative to the total weight of titanium oxide with a pulp and/or a paper blended at the above ratio.

Abstract: A hybrid system for processing papermaking fibers includes a multistage array of forward cleaners coupled with a flotation cell which increases overall efficiency of the system. In a typical embodiment, a first rejects aqueous stream from a first stage bank of centrifugal cleaners is treated in a flotation cell before being fed to a second stage bank of centrifugal cleaners.

Abstract: A repulpable wax containing paper product consists essentially of a hot melt formulation with an effective amount of an inorganic mineral filler such as clay. The inorganic mineral filler is in an amount which permits the article coated with the hot melt—inorganic mineral filler formulation to be repulped and recycled.

Abstract: A process for the production of pulp using alkaline delignification is disclosed, wherein cellulosic material is initially treated with steam, and a chelating agent is added in connection with the steam treatment. The end pH of the steam treatment stage is below 5. Liquors containing chelated, so-called non-process compounds are not recycled in the pulping process, but expelled therefrom for further processing where non-process compounds are eliminated.

Abstract: A product and process of making an absorbent paper article such as paper products, towels, napkins and the like is disclosed. In the invention, one may supply a single furnish, or slurry, of cellulose fibers. Then, it is possible to separate or fractionate the slurry into at least two portions based upon fiber length in the slurry. Fines are employed in the process of manufacturing the products, and fines are specifically incorporated into an inner layer of the final paper products. Fines, short fibers, and/or fibrils are used in the process so they may contribute in a positive manner to the final paper product, rather than acting in a negative manner as a chemical “sponge” or waste material. This use of fines in the inner layers of the product reduces the manufacturing cost and waste produced in the process. A soft paper product with good strength characteristics results from the process.

Abstract: The invention provides a process and apparatus for the treatment and recovery of fiberboard and particle board waste. Waste fiberboard and particle board is fed into a steam chamber and steam treated with steam under pressure from a steam generator. When the steam treatment is completed any effluent and excess steam are evacuated from the chamber and the steam treated waste is passed through a rotating trommel. Woodfibers and woodchips pass through the screens of the trommel and are collected for drying and further processing. Waste material, such as melamine coatings, passes through the trommel for collection and disposal. The collected woodfiber and woodchips can be processed for reuse in paper, cardboard or particle board manufacture or as mulch and other ground cover material.

Abstract: A double layer papermaking fabric having twice as many paper side cross machine direction yarns as machine side cross machine direction layer. A system of machine direction yarns is interwoven with both cross machine direction layers, with each machine direction yarn forming first and second knuckles on each side of the fabric. The paper side knuckles are woven with uniform spacing and each machine side cross machine direction yarn is passed under by two machine direction knuckles spaced by at least one intermediate machine direction yarn.

Abstract: In a tall oil refining operating plant, a warm water loop is disclosed for cooling the tall oil heads fraction extracted from the crude tall oil, rather than the conventional use of cold water. This avoids condensation and the subsequent solidification of athraquinone pulping aid remaining in the crude tall oil; thus, avoiding fouling of the cooling towers. The temperature of the warm-water is controlled automatically by tempering the cold water entering the warm water “cooling” loop, while removing excessively warm water from said loop to the cooling tower system, as needed.

Abstract: Process and apparatus for removing fine impurities from a fibrous suspension. The process and apparatus each provide for conveying the fibrous suspension to at least one sorting device, separating the fibrous suspension using the at least one sorting device into an accepts portion and a rejects portion, finishing at least some of the accepts portion leaving the at least one sorting device using a finishing device, separating at least some portion of the rejects portion leaving the at least one sorting device using at least one last sorting device into an accepts portion and an rejects portion, separating at least some portion of the accepts portion leaving the at least one last sorting device into an accepts portion and a rejects portion using a flotation device, and finishing at least some portion of the accepts portion leaving the flotation device using the finishing device.

Abstract: The invention relates to a method of recovering energy in a forming section of a papermaking or boardmaking machine, wherein stock from a headbox is fed into a forming zone of a forming section, said forming zone including at least one looped forming fabric curving along a convex surface of a support member, and water is drained from the stock through said at least one forming fabric in the forming zone to form a paper or board web, the water passing through said at least one fabric being thrown out from the forming zone and possessing kinetic energy, characterized by placing a movable component in the water thrown out from the forming zone, so as to cause the water to move the component, and thereby recovering part of the kinetic energy. The invention also relates to an arrangement in a papermaking or boardmaking machine.

Abstract: In the method for threading of a paper or paperboard web a narrower tail (T) separated from the paper or paperboard web (W) is conveyed between different holding points. On the travel path of the tail (T) there is at least one tension measuring device (1) which is arranged to measure the tension of the tail (T) passing by, said device (1) being connected to a data processing unit (7) which is connected to tension control means affecting the tail (T). The threading can be conducted on a tension level lower than the actual running tension of the full-width web (W).