A method and system for heating a hydraulic digester, such as a single-vessel hydraulic digester, which has a top separator, a level of chips and a liquid phase above the level of chips. The method includes: a. entraining chips in liquor to produce a slurry having a first temperature, b. feeding the slurry of chips to the digester through the top separator, c. supplying direct steam to the liquid phase between the level of chips and the top separator to heat the slurry to a second temperature for the impregnation stage, wherein the steam is fed by using at least one steam injector having a plurality of steam discharge openings; and d. heating the slurry to a third temperature and cooking the chips in a cooking zone, and withdrawing the cooked pulp from the bottom of the digester.

A method and system for heating a hydraulic digester, such as a single-vessel hydraulic digester, which has a top separator, a level of chips and a liquid phase above the level of chips. The method includes: a. entraining chips in liquor to produce a slurry having a first temperature, b. feeding the slurry of chips to the digester through the top separator, c. supplying direct steam to the liquid phase between the level of chips and the top separator to heat the slurry to a second temperature for the impregnation stage, wherein the steam is fed by using at least one steam injector having a plurality of steam discharge openings; and d. heating the slurry to a third temperature and cooking the chips in a cooking zone, and withdrawing the cooked pulp from the bottom of the digester.

The present invention relates to an outlet system for transporting comminuted lignocellulosic material from a vessel, said bottom portion (1) having an upper circumference (15) that is essentially circular and a lower circumference (16) comprising at least two essentially straight portions (16a, 16c) opposite each other. The invention also relates to a vessel having such an outlet system.

The present invention relates to an outlet system for transporting comminuted lignocellulosic material from a vessel, said bottom portion (1) having an upper circumference (15) that is essentially circular and a lower circumference (16) comprising at least two essentially straight portions (16a, 16c) opposite each other. The invention also relates to a vessel having such an outlet system.

A cooking method and a digester system wherein partly digested cellulosic fiber source is compressed during cooking to provide high molecular weight lignin and pulp.

A cooking method and a digester system wherein partly digested cellulosic fiber source is compressed during cooking to provide high molecular weight lignin and pulp.

The present invention relates to a method of producing holocellulose fibres by treating a wood-based raw material with an organic peroxide, wherein the method comprises charging the organic peroxide continuously to the wood-based raw material during the treatment and/or charging the organic peroxide to the wood-based raw material in at least two separate steps with an intermediate alkaline treatment step. Additionally, a process for the production of paper comprising the steps of preparing a papermaking stock comprising an aqueous pulp slurry comprising cellulosic fibres and having a fibre consistency of from 0.1 to 40% by weight, wherein the cellulosic fibres comprise or consist of holocellulose fibres, and wherein the amount of the wood-based holocellulose fibres is from 0.5 to 100% by weight, based on the total weight of the stock; providing the stock to a wire and form a web; dewatering the web; and drying the web is claimed. By the method affordable way to produce holocellulose fibres usable in the process to provide paper with high strength is provided, while effective dewatering can be obtained during the manufacturing process.

The present invention relates to a method of producing holocellulose fibres by treating a wood-based raw material with an organic peroxide, wherein the method comprises charging the organic peroxide continuously to the wood-based raw material during the treatment and/or charging the organic peroxide to the wood-based raw material in at least two separate steps with an intermediate alkaline treatment step. Additionally, a process for the production of paper comprising the steps of preparing a papermaking stock comprising an aqueous pulp slurry comprising cellulosic fibres and having a fibre consistency of from 0.1 to 40% by weight, wherein the cellulosic fibres comprise or consist of holocellulose fibres, and wherein the amount of the wood-based holocellulose fibres is from 0.5 to 100% by weight, based on the total weight of the stock; providing the stock to a wire and form a web; dewatering the web; and drying the web is claimed. By the method affordable way to produce holocellulose fibres usable in the process to provide paper with high strength is provided, while effective dewatering can be obtained during the manufacturing process.

A method for feeding a slurry of chips and liquid to a prehydrolysis reactor in the production of dissolving pulp. The slurry is pumped by using at least one pump to the reactor, and alkali is fed into the at least one pump 5 for adjusting the pH of the slurry to a range of 7-10.

A method for feeding a slurry of chips and liquid to a prehydrolysis reactor in the production of dissolving pulp. The slurry is pumped by using at least one pump to the reactor, and alkali is fed into the at least one pump 5 for adjusting the pH of the slurry to a range of 7-10.