Kvaerner Pulping Ab

Kvaerner Pulping Technologies Ab

Sven-Erik Olsson

Vidar Martin Snekkenes

Lennart Gustavsson

Johanna Svanberg

Stig Andtbacka

Per Johan Nystrom

Kenneth Olof Bellstrom

Finn Jacobsen

ANGke Backlund

Peter Christen Kylin

Christen Gro Hansen

The invention relates to a process for continuous cooking of wood chips at elevated pressure and temperature in a vertical digester ( ) 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 ( ), 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. 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.

Process for continuous cooking of pulp

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.

Chip bin

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.

Separator having a screen basket disposed in a digester

Method of continuously isothermally cooking of pulp

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Sunne, Sweden

Sven-Erik Olsson