COLUMN FOR PURIFICATION BY DISTILLATION OF CARBOXYLIC ACID ANHYDRIDES

摘要

The invention relates to a column (1) for purification by distillation of carboxylic acid anhydrides, comprising a bottoms circulation stream in which an evaporator (21) is accommodated, and a pump (23), in order to direct product removed from the sump through the evaporator (21) and back into the column. The pump (23) is a magnetically coupled pump, in which a magnetic holder (27) extending in the axial direction is formed on the outer circumference of the rotor (25), and the rotor (25) is closed by means of a containment shell (39) on the side opposite the suction side.