Evaporation of bleach filtrate in the gas cooling system of a plant for gasifying black liquor

摘要

Method for recovering/purifying bleaching effluents from a bleaching plant (20) for cellulose fibre, in which bleaching filtrate (6) is supplied to a gas cooling system adherent to a plant (22) for partial or overstoichiometric combustion of cellulose spent liquors, whereby the water content of the filtrate wholly or partially is converted into steam, which steam subsequently is cooled, after which thereby formed condensate (12) is drawn off for direct or indirect return to the process water system of the pulp mill.