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Lennart Kållén

Mikael H Lindstrom

Christofer Lindgren

Lars Ledung

Ulf Persson

Tomas Lindberg

Lennart Borjeson

Per-Olof Sahlin

Green liquor clarification comprising filtering of a flowing suspension containing solids, wherein the suspension is brought into contact with a first filter unit (), said 5 filter unit () comprising one or several filter elements () comprising one or several filter bodies () having filter channels () within the filter bodies () with a filtering layer (), a part of the suspension is forced to pass through the filtering layer () from a first/inner surface (A) to a second/outer surface (B) of the filtering layer () forming a filtrate while the solids substantially remains in a residual part of the suspension forming a slurry and where the filtering layer () is made of a membrane material with pores, said pores having a pore size of 0.1-10 micrometer, more preferred 0.1-5 micrometer and most preferred 0.2-1.0 micrometer.

Method and arrangement for clarifying green liquor

A process is modeled by a dynamic model, handling time dependent relations between manipulated variables of different process sections (A&#x2013;D) and measured process output variables. Suggested input trajectories for manipulated variables for a subsequent time period are obtained by optimizing an objective function over a prediction time period, under constraints imposed by the dynamic process model and/or preferably a production plan for the same period. The objective function comprises relations involving predictions of controlled process output variables as a function of time using the process model, based on the present measurements, preferably by a state estimation procedure. By the use of a prediction horizon, also planned future operational changes can be prepared for, reducing any induced fluctuations. In pulp and paper processes, process output variables associated with chemical additives can be used, adapting the optimization to handle chemical additives aspects.

Dynamic on-line optimization of production processes

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Forshaga, Sweden

Lennart Kållén