PROCESS FOR PURIFYING POLYCARBONATE POLYOLS AND PURIFYING APPARATUS THEREFOR

摘要

The present invention relates to a purifying apparatus for polycarbonate polyols, especially for removal of cyclic alkylene carbonates, comprising an evaporation unit (1) provided with a heater (10) and having an inlet (6) disposed at the top end thereof and a bottoms vessel (11), and a stripping column (2) connected downstream of the evaporation unit (1) and having a top (21) and a bottom (23), wherein a feed (5) for the polycarbonate polyol to be purified opens into the inlet (6) to the evaporation unit (1) and a gas outlet line (12) and a connecting line which opens into the top (21) of the stripping column (2) and is equipped with a pump (18) depart from the evaporation unit (1), and wherein a gas inlet line (24) for an inert gas opens into the bottom (23) of the stripping column (2) and a product line (27) for the purified polycarbonate polyol departs from the bottom (23) of the stripping column (2) and a gas outlet line (25) departs from the top (21) of the stripping column (2). The invention additionally relates to a process for purifying polycarbonate polyols with such a purifying apparatus.