Abstract: 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.

Abstract: Fiber material and cooking liquor are introduced at the top of the digester and pulp is discharged from the bottom of the digester, via a line in which the pulp is maintained at substantially the same pressure level, to a pressurized wash. 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. At the same time a small portion of the wash filtrate is also to be recirculated to the bottom of the digester as dilution liquid. 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.

Abstract: 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.

Abstract: 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.

Abstract: Chip bin comprising, an upper container part, a discharge opening, and, arranged between the container part and the discharge opening, a discharge zone, preferably without moving parts, the discharge zone having a curvilinear roller shape in any freely chosen horizontal cross-section and the number of corners in the geometrical curvilinear figure of the cross-section is more than two, preferably three, in that the cross-section of the discharge zone decreases from the container part (5) down towards the discharge opening (4), and in at least one section of the discharge zone having a downwardly continuously decreasing curvilinear roller shaped cross-section.

Abstract: 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. The digesting process includes a top separator that separates the transport liquid from the fiber material and permits the fiber material to be exposed to the cooking liquid.

Abstract: A chip bin that has a feeding device, an upper container part and a discharge opening defined therein. A discharge zone is disposed between the upper container part and the discharge opening. The discharge zone has no moving parts and has a diameter that is decreasing from the upper container part down towards the discharge zone. The discharge zone has a discharge section in the form of a truncated cone that has a downwardly continuously decreasing circular cross section. The discharge section has a center line extending therethrough so that the center line and the longitudinal vertical axis of the chip bin form an acute angle alpha.

Abstract: The present invention relates to a digester for continuous cooking, under elevated pressure and temperature, of fibre material in a vertical digester (1), where fibre material and cooking liquid are fed into the top of the digester, used cooking liquor is drawn off from at least one digester screen arrangement (1D) between the top and the bottom of the digester, and fibre material is fed out from the bottom of the digester, it being possible to maintain the temperature in the cooking zone immediately above the digester screen arrangement (1B) at essentially the same temperature level as the remaining cooking zone or cooking zones of the digester.