Abstract: 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 of 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 A final cooking fluid is present during the cook for the major part of the cook and is withdrawn through a withdrawal strainer only during the final 15 minutes of the cook.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 The withdrawn final cooking fluid during the final 15 minutes of the cook consists of spent black liquor that maintains a residual alkali level that lies under 15 g/l.

Abstract: An device, system and method of using is disclosed to provide a releasably attached external tension member(s), earth anchor(s), net(s), means for adjusting and means for attaching to the earth anchor(s) to accomplish an emergency structure restraint system.

Abstract: 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 A final cooking fluid is present during the cook for the major part of the cook and is withdrawn through a withdrawal strainer only during the final 15 minutes of the cook. The final cooking fluid ensures a fluid/wood ratio that is greater than 3.5 in association with the withdrawal The withdrawn final cooking fluid during the final 15 minutes of the cook consists of spent black liquor that maintains a residual alkali level that lies under 15 g/l.

Abstract: The method is for cooking of cellulose pulp in which the raw material, preferably in the form of chips, undergoes a successive elevation of temperature towards the cooking temperature while the chips are first impregnated with an impregnation liquor followed by cooking in a cooking liquor that is preferably alkali. Through the addition of pre-evaporated black liquor, either as early as the impregnation stage or during the subsequent cooking stage, an improved delignification process is achieved in which the pulp obtains improved properties, primarily with respect to strength/viscosity for a given degree of delignification, and also with respect to yield. The method can be used both for continuous cooking and for batch cooking of cellulose pulp.

Abstract: An device, system and method of using is disclosed to provide a releasably attached external tension member(s), earth anchor(s), net(s), means for adjusting and means for attaching to the earth anchor(s) to accomplish an emergency structure restraint system.

Abstract: The continuous digester is for producing chemical pulp to a process for operating this digester and to a feedback system for the cooking liquid. By means of implementing cooking zones 1st, 2nd, 3rd, 4th and 5th down through the digester, that have a successively decreasing liquid-to-wood ratio, it is possible to obtain a more uniform alkali profile during the cooking. The alkali is kept high at the beginning by means of a high liquid-to-wood ratio, typically over 6:1, which exceeds conventional liquid-to-wood ratios, which are normally around 3.5-5.0:1.

Abstract: The method is for the manufacture of cooked cellulose pulp in which the starting material, preferably chips, undergoes a successive increase in temperature towards cooking temperature. This is done while the chips are first treated in a pre-treatment zone in which the main part, greater than 50%, of fresh white liquor necessary for the cooking stage is added, after which this alkali-rich treatment fluid is withdrawn and replaced to a major extent by black liquor. The alkali-rich treatment fluid that has been withdrawn after the pre-treatment stage is then added to the cooking stage, which is why the addition of fresh white liquor to the cooking stage is reduced to an equivalent amount. Maximal yield-enhancing effect is obtained using poly-sulphide-rich white liquor during the pre-treatment at a temperature in the interval 60±40° C. and retention time in the interval 2-60 minutes, preferably 2-10 minutes.

Abstract: The process is for continuously cooking chemical pulp in a digester system consisting of at least one vessel for impregnating and cooking comprising an inlet into which a mixture of chips and process liquid is fed. The chips are impregnated at a predetermined impregnation temperature, Timp, and cooked at a predetermined cooking temperature, Tcook, after which dissolved pulp is fed out at the outlet of the digester system. The process liquid which is continually extracted is retained outside the digester system during a dwell time, t, of at least 30 min, without any heating above 140°, and thereafter returned to the digester system to a position which is substantially at the same level as the extraction, or downstream thereof, and thereby constitute part of the process liquid in the subsequent treatment zone. The process results in improved tear strength, beatability, bleachability and reduced color reversion, and increased yield across the digester.

Abstract: The invention concerns a method for the production of cellulose pulp. A wood raw material that principally comprises softwood, preferably in the form of cut wood chips, is treated in several stages in various treatment steps. One of the stages is cooking the material in an alkali cooking fluid, with the aim of obtaining improved quality with respect to tensile strength, and of obtaining higher yield. A controlled addition of wood raw material in the form of hardwood at an amount corresponding to 1-20% of the amount of softwood, preferably 3-15%, and more preferably at least 5%, takes place.

Abstract: The method is for cooking of cellulose pulp in which the raw material, preferably in the form of chips, undergoes a successive elevation of temperature towards the cooking temperature while the chips are first impregnated with an impregnation liquor followed by cooking in a cooking liquor that is preferably alkali. Through the addition of pre-evaporated black liquor, either as early as the impregnation stage or during the subsequent cooking stage, an improved delignification process is achieved in which the pulp obtains improved properties, primarily with respect to strength/viscosity for a given degree of delignification, and also with respect to yield. The method can be used both for continuous cooking and for batch cooking of cellulose pulp.

Abstract: The method is for the manufacture of cooked cellulose pulp in which the starting material, preferably chips, undergoes a successive increase in temperature towards cooking temperature. This is done while the chips are first treated in a pre-treatment zone in which the main part, greater than 50%, of fresh white liquor necessary for the cooking stage is added, after which this alkali-rich treatment fluid is withdrawn and replaced to a major extent by black liquor. The alkali-rich treatment fluid that has been withdrawn after the pre-treatment stage is then added to the cooking stage, which is why the addition of fresh white liquor to the cooking stage is reduced to an equivalent amount. Maximal yield-enhancing effect is obtained using poly-sulphide-rich white liquor during the pre-treatment at a temperature in the interval 60±40° C. and retention time in the interval 2-60 minutes, preferably 2-10 minutes.

Abstract: The process is for continuously cooking chemical pulp in a digester system consisting of at least one vessel for impregnating and cooking comprising an inlet into which a mixture of chips and process liquid is fed. The chips are impregnated at a predetermined impregnation temperature, Timp, and cooked at a predetermined cooking temperature, Tcook, after which dissolved pulp is fed out at the outlet of the digester system. The process liquid which is continually extracted is retained outside the digester system during a dwell time, t, of at least 30 min, without any heating above 140°, and thereafter returned to the digester system to a position which is substantially at the same level as the extraction, or downstream thereof, and thereby constitute part of the process liquid in the subsequent treatment zone. The process results in improved tear strength, beatability, bleachability and reduced color reversion, and increased yield across the digester.

Abstract: The invention relates to a continuous digester for producing chemical pulp, to a process for operating this digester and to a feedback system for the cooking liquid. By means of implementing cooking zones 1st, 2nd, 3rd, 4th and 5th down through the digester, having a successively decreasing liquid-to-wood ratio, it is possible to obtain a more uniform alkali profile during the cooking. The alkali which is totally available is kept high at the beginning by means of a high liquid-to-wood ratio, typically well over 6:1, which well exceeds conventional liquid-to-wood ratios, which are normally around 3.5-5.0:1. In combination with digester liquid from subsequent cooking zones being fed back to the top of the digester, the alkali concentration can be kept low at the beginning of the cooking, typically within 20-35 g/l when cooking softwood. This is achieved with essentially all the alkali, i.e. more than 80%, being added at the beginning of the cooking.

Abstract: A method for continuous cooking of lignocellulosic fiber material, comprising the steps of sequentially (a) in a first stage, impregnating the fiber material in an impregnation liquid comprising alkali metal hydroxide, and thereafter withdrawing (14, 514) a spent impregnation liquid; (b) in a second stage, cooking the fiber material in a cooking liquor comprising alkali metal hydroxide; and (c) in a third stage, adding (A), to said fiber material, a liquid which is rich in hemicellulose, said liquid preferably comprising at least a part (14a, 514a) of said withdrawn spent impregnation liquid. In a fourth stage (d), the fiber material is cooked in a cooking liquor comprising the liquid added in the third stage, whereby the fiber material is subjected to a retention time of at least 1 hour in said fourth stage.

Abstract: This invention relates to a new and improved way of continuously cooking fiber material, wherein temperatures and alkaline levels are controlled to be maintained within specific levels in different zones of the digesting process in order to optimize chemical consumption and heat-economy, and, at the same time, achieving very good pulp properties.

Abstract: This invention relates to a new and improved way of continuously cooking fiber material, wherein temperatures and alkaline levels are controlled to be maintained within specific levels in different zones of the digesting process in order to optimize chemical consumption and heat-economy, and, at the same time, achieving very good pulp properties.

Abstract: This invention relates to a new and improved way of continuously cooking fiber material, wherein temperatures and alkaline levels are controlled to be maintained within specific levels in different zones of the digesting process in order to optimize chemical consumption and heat-economy and at the same time achieve very good pulp properties.

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.