Evaporating method for hot black liquor obtained from digestion process during production of cellulose pulp, involves cooling hot black liquor by heat exchange with black liquor partially evaporated in evaporation stage in evaporation line

摘要

The evaporating method involves leading a hot black liquor to a multistage evaporation line with at least five evaporation stages (I,II). The hot black liquor, which is to undergo evaporation in the evaporation line, is cooled by heat exchange with a black liquor that has been at least partially evaporated in an evaporation stage in the evaporation line. An independent claim is also included for a hot black liquor evaporation equipment.