Abstract: 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 (10) that comprises an upper part (11) with a first area and a lower part (13) with a second area A2 that is larger than the first area A1 by a factor of at least r2. The chips establish in the upper part (11) a level (14) of chips that is located at a level (h) above a level (18) of fluid consisting of liquor. The chips after passage of the upper part (11) pass through a transitional part (12), where an increase in area from the first area (A1) to and it is here that the angle of repose of the chips is reduced.

Abstract: 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.

Abstract: 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the chips suspension is placed under pressure for onwards transport to a subsequent digester, a fraction of fluid is withdrawn from the chips suspension, whereby a third fluid/wood ratio is established in the chips suspension.

Abstract: 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 LiqLEV 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.

Abstract: The method is for bleaching cellulose pulp in a bleaching line that has at least two bleaching steps including a first and second bleaching steps. The bleaching steps have wash apparatuses for the pulp arranged after the first and second bleaching steps. The dilution liquor is led in counter-currently to the pulp flow through the bleaching steps in the bleach line. A substantial portion of the wash liquor is supplied by means of a main conduit so that each of the wash apparatuses is independently supplied by means of first branch conduits connected to the main conduit. Each of the wash apparatuses independently bleeds out wash filtrate by means of second branch conduits connected to the main conduit. The main conduit has an outlet end which bleeds out at least some of the wash filtrate from the wash apparatus.

Abstract: The method is for bleaching cellulose pulp in a bleaching line that has at least two bleaching steps including a first (D1) and a second (D2) bleaching step. The bleaching steps have wash apparatuses (W4, W5) for the pulp arranged after the first and the second bleaching step. Wash liquor and where appropriate dilution liquor is led in principle in counter-current to the pulp flow through the bleaching steps in the bleach line (W1-D0-W2-EO/EOP-W3-D1-W4-D2-W5). At least one of wash liquor and dilution liquor is taken to the subsequent wash (W5) of the second bleaching step (D2) and at least a part of the wash filtrate from the subsequent wash of the second bleaching step is led to a second branch position (A2) in the main conduit.

Abstract: The invention concerns a method and a device for the dilution of dewatered cellulose pulp that maintains a consistency of 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 the granulate at a position at which the granulate is in free fall in a stand pipe 22, 40 and above a level LiqLEV of diluted pulp in the stand pipe. 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 is operating costs, while at the same time unnecessary mechanical influence of the pulp fibres can be avoided.

Abstract: A procedure for the continuous cooking of chemical pulp, comprising an impregnation vessel 101 and a digester 102. The chips are impregnated in the impregnation vessel 101 and are fed after impregnation together with circulation fluid through a transfer line 103 to a top separator 105 on the digester 102 in order to be cooked. A fraction of the circulation fluid is withdrawn at a top separator 105 and returned to the bottom of the impregnation vessel 101 via a return line 106. Black liquor is withdrawn from the digester via a black liquor line 108 to the impregnation vessel 101. The invention is characterised in that a heat exchanger 107 is arranged between the return line 106 and the black liquor line 108. The heat exchanger 107 allows the exchange of heat between the two lines, but does not allow the exchange of fluid. The temperature of the black liquor in the black liquor line 108 after passing through the heat exchanger 107 has been cooled by 10-15 ° C.