METHOD AND ARRANGEMENT FOR CLEANING CONTAMINATED CONDENSATE INCLUDING A COMBINED STRIPPER/CONDENSER

This invention relates to a method for cleaning unclean condensate, emanated when producing cellulose pulp including evaporation of spent liquor under utilization of a cleaning plant having several condensers, coupled in series , characterized in that process steam from the last evaporation stage and unclean condensate are introduced into a combined stripper/condenser, the process steam and the condensate being brought to flow in opposite direction s so that direct heat exchange occurs, resulting in that volatile compounds of the condensate are separated and are taken up by the steam under simultaneou s indirect cooling, resulting in condensation of the main part of the process steam, that the remaining process steam is gradually flowing furtheron, the process steam being successively cooled indirectly, resulting in that water and turpentine are first condensed and collected and that methanol is condensed, collected condensate being separated from turpentine, which is removed from the plant and is reintroduced to the stripper/condenser and tha t methanol is removed from the plant, that principally cleaned condensate is collected at the bottom of the combined stripper/condenser and is removed fr om the plant or is further purified. The invention also relates to a cleaning plant.