procedure for the regulation of tillforsel of reaktionskemikalier at delignifiering and / or bleaching of the pulp

摘要

The delignification and/or bleaching of cellulose by treating a cellulose suspension contg. chemical-consuming materials with reaction chemicals, supplying to a treatment stage, in which these chemicals are wholly or partly consumed and adding during and/or after the reaction is regulated in accordance with measured values of the reaction chemicals content is improved by determining the requirement of the reactants of the suspension prior to the treatment stage as well as the content of residual unused reaction chemicals together with the measured value obtained and using for the control of the addition of reaction chemicals to the cellulose suspension before and if necessary also after the treatment stage. The lignum analysis may be carried out continuously and accurately, directly in the process stream to which the bleach addition is to be regulated. In addition the analysis before the bleaching stage gives information on the effectiveness of the cooker lye recovery.