摘要:
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.
摘要:
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.
摘要:
The method is for feeding a chips-slurry from a low-pressure to a high-pressure system during the continuous cooking of chemical cellulose pulp. The feed takes place through a sluice feeder 53′ between these systems. The sluice feeder is provided with a rotor with through-pockets 1, 2 that are alternately connected with the low-or the high-pressure system. A recirculation line 54′, that has a high-pressure pump 57′, extends from the first outlet 53b′ of the sluice feeder to the second inlet 53c′ of the sluice feeder for transporting the fluid that has been expelled from the pockets of the sluice feeder when these are located in their first position. The fluid expels the chips mixture from the pockets of the sluice feeder in their second position and is essentially exclusively constituted by the fluid that has been expelled from the pockets in their first position.
摘要:
A method for the continuous cooking of chemical pulp with the aim of achieving improved heat economy in a digester system having a vessel (1) for impregnation and a vessel (2) for cooking the impregnated cellulose chips. A part of the black liquor (14) withdrawn from the digester (2) is added at the beginning of a transfer system (4) to increase the temperature of the chips mixture in the transfer system (4). A fraction of the transport fluid (10) from the transfer system (4) that is continuously withdrawn from the impregnated chips fed into the top of the digester is returned to the impregnation vessel (1) at essentially the maintained transfer temperature.
摘要:
The method is for feeding a chips-slurry from a low-pressure to a high-pressure system during the continuous cooking of chemical cellulose pulp. The feed takes place through a sluice feeder 53′ between these systems. The sluice feeder is provided with a rotor with through-pockets 1, 2 that are alternately connected with the low- or the high-pressure system. A recirculation line 54′, that has a high-pressure pump 57′, extends from the first outlet 53b′ of the sluice feeder to the second inlet 53c′ of the sluice feeder for transporting the fluid that has been expelled from the pockets of the sluice feeder when these are located in their first position. The fluid expels the chips mixture from the pockets of the sluice feeder in their second position and is essentially exclusively constituted by the fluid that has been expelled from the pockets in their first position.
摘要:
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.
摘要:
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.
摘要:
A method 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 that has an upper part with a first area (A1) and a lower part with a second area (A2) that is larger than the first area (A1) by a factor of at least √{square root over (2)}. The chips establish in the upper part a level of chips that is located at a level (h) above a level of fluid consisting of liquor. The chips after passage of the upper part pass through a transitional part, where an increase in area from the first area (A1) to the second area (A2) takes place, and it is here that the angle of repose of the chips is reduced.
摘要:
The invention relates to a method for supplying washing liquid to a digester (1) for cellulose pulp and a subsequent diffuser washing device (2a, 2b). A high, disturbance-free production capacity can be obtained by using a common feed pump (P1) which, via a main feed line (10), supplies both the diffuser washing device and the digester with washing liquid in parallel. The first pump (P1) establishes a pressure on the washing liquid which is in the interval 2–6 bar, and is preferably 4 bar, while the second pressure level, which is established by the diffuser pump device (P2a, P2b), is in the interval 6–12 bar, but is at least 2 bar higher than the first pressure level, and the third pressure level, which is established by the digester pump (P3), is in the interval 12–25 bar The system becomes self-regulating in the event of any operational disturbances in the flow of washing liquid and, if the pumps are appropriate, a countercurrent flow of washing liquid through the system is essentially maintained.
摘要:
The invention relates to a process for continuous cooking of wood chips at elevated pressure and temperature in a vertical digester (1) for production of chemically dissolved pulp. Fiber material and cooking liquor are introduced at the top of the digester and pulp is discharged from the bottom of the digester (1), via a line (8) in which the pulp is maintained at substantially the same pressure level, to a pressurized wash (7). More than 50% of the used cooking liquor (black liquor) which is extracted from the system in total is extracted from the wash filtrate of the pressurized wash. The pressurized wash is regulated so that a high temperature is maintained in the wash filtrate. The extraction is regulated so that a net co-current flow is established at the bottom of the digester.