Patent application number | Description | Published |
20080202712 | Method and Device for the Continuous Cooking of Pulp - The continuous digester system has an inlet defined therein for the feed of a chips suspension and an outlet for the output of a cooked suspension of pulp. The suspension or chips is fed in to the inlet through a line at the beginning of the cook, where the chips suspension has a volume of starting cooking fluid that establishes a fluid/wood ratio that is greater than 3.5. A final cooking fluid is present during the cook for the major part of the cook and is withdrawn through a withdrawal strainer only during the final 15 minutes of the cook. The final cooking fluid ensures a fluid/wood ratio that is greater than 3.5 in association with the withdrawal The withdrawn final cooking fluid during the final 15 minutes of the cook consists of spent black liquor that maintains a residual alkali level that lies under 15 g/l. | 08-28-2008 |
20080202717 | Arrangement for Feeding a Slurry of Chips and Liquid - The method and arrangement is for the feed of a chips suspension from one vessel to a subsequent digester in a continuous cooking process for the production of chemical cellulose pulp. The vessel has an inlet defined therein for the input of chips and an outlet defined therein for the output of a chips suspension. The chips suspension in the vessel has a first fluid/wood ratio established above a second fluid/wood ratio that is established at the bottom of the vessel. The second fluid/wood ratio is at least as great as, preferably greater than, the first fluid/wood ratio. After the output of the chips suspension from the vessel and before the chips suspension is placed under pressure for onwards transport to a subsequent digester, a fraction of fluid is withdrawn from the chips suspension, whereby a third fluid/wood ratio is established in the chips suspension. | 08-28-2008 |
20080210392 | METHOD FOR PRODUCING CELLULOSE PULP IN A CONTINUOUS DIGESTER IN AN ENERGY-EFFICIENT MANNER - The method is for producing cellulose pulp in a continuous digestion system in an energy-efficient manner. Cellulose chips are fed continuously with a transfer liquid in a transfer line to a top separator arranged at the top of a digester, for the separation of free liquid from the cellulose chips. The top separator has a withdrawal space in which free liquid collects. At least a fraction of the free liquid that has separated, with a temperature T | 09-04-2008 |
20080271861 | Method for Oxygen Delignification of Cellulose Pulp by Mixing of Chemicals - The method is for the improved oxygen delignification of cellulose pulp with a medium consistency of 8-16%. The fraction of dissolved oxygen can be maintained at a high level throughout the process by the use of high pressure, greater than 15.0 bar, and by repeated agitative mixing while maintaining the high pressure. A fraction just over 20% of the total oxygen added is dissolved in the fluid phase such that the amount of oxygen in the fluid phase is maintained at a high level throughout the complete high-pressure section. This means that the amount of oxygen that is dissolved in the fluid phase and that penetrates the cellulose fibers can be maintained at an optimal high level throughout the process for improved delignification of the cellulose. | 11-06-2008 |
20080277081 | Method and Arrangement For Impregnation of Chips - A method and an arrangement for the impregnation of untreated chips during the manufacture of chemical pulp. The untreated chips are fed without preceding steam treatment into an impregnation vessel ( | 11-13-2008 |
20090071615 | CONTINUOUS DIGESTER WITH FLUID CIRCULATION - The arrangement concerns an improved design for at least one of the cooling, dilution and washing at the bottom of a continuous digester for the production of cellulose pulp. By arranging at least one extra strainer section above the lowermost strainer section, with the addition of washing fluid or dilution fluid between the extra strainer section and the lowermost strainer section, more washing fluid can be added at the bottom of the digester without counteracting the flow of the column of chips. This provides space for the increase of production, for improvement of the flow of the column of chips, or for combinations of these effects while retaining good cooling, washing and dilution at the bottom of the digester. | 03-19-2009 |
20090107642 | METHOD FOR OXYGEN DELIGNIFICATION OF CELLULOSE PULP AT HIGH PRESSURE IN SEVERAL STEPS - The method is for the improved oxygen delignification of cellulose pulp with a medium consistency of 8-16%. The fraction of dissolved oxygen can be maintained at a high level throughout the process by the use of high pressure, greater than 15.0 bar, and by repeated agitative mixing while maintaining the high pressure, such that as large a fraction as just over 20% of the total oxygen added is dissolved in the fluid phase, and such that the amount of oxygen in the fluid phase is maintained at a high level throughout the complete high pressure section. By the establishment of retention times between the remixing operations with successively increasing retention times, while retaining a high pressure, an optimal adaptation of the remixing is obtained at the time at which a certain fraction of the oxygen dissolved in the fluid phase has been consumed. | 04-30-2009 |
20120012271 | Device for Dilution of Cellulose Pulp - The method and a device is for the dilution of dewatered cellulose pulp that maintains a consistency of 20-30% or greater. By shredding of the pulp to a finely divided dry-granulate, dilution to a homogeneous consistency in the medium consistency range can take place exclusively through hydrodynamic effects from the addition of dilution fluid. The dilution fluid is added to granulate at a position at which granulate is in free fall in a standpipe and above a level Liq.sub.LEV of diluted pulp in the standpipe. A number of nozzles are arranged around the periphery of the stand pipe, directed in towards the centre of the stand pipe, obliquely downwards in the direction of fall of the granulate. It is possible through this simplified procedure to avoid completely the conventional dilution screws, and this reduces the investment costs and operating costs, while at the same time unnecessary mechanical influence of the pulp fibres can be avoided. | 01-19-2012 |