摘要 |
The invention relates to a system for the oxygen delignification, in at leas t two reaction stages, of pulp which consists of lignocellulose-containing material and whose mean concentration is 8-18% pulp consistency. The oxygen delignification takes place in a first reaction stage (6) in which an essentially constant and low pressure prevails during the whole of the delignification process, after which the second delignification stage (10), with a substantially higher pressure and temperature and a longer dwell time, begins. The invention is characterised in that the first reaction stag e (6) consists of a pipe loop arranged to lie essentially in the same horizontal plane.
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