Method and apparatus for treating pulp

摘要

The present invention relates to a method of and apparatus for treating pulp. More precisely, the present invention relates to a method and apparatus for treating pulp with oxygen. Especially preferably the method and apparatus according to the invention relate to oxygen delignification of chemical pulp, i.e. so-called oxygen bleaching. A characterizing feature of the method according to the invention of treating chemical pulp in an oxygen bleaching stage where the pulp is bleached in at least one pressurized reactor in the presence of alkali is that the whole oxygen stage is effected pressurized and that a bigger amount of alkali than conventional is fed in the beginning of the oxygen stage and that the whole alkali dose is fed in the beginning of the oxygen stage.