TVETTFORFARANDE

摘要

A solid product impregnated with a liquid substance is subjected to successive washing operations in a washing zone by a process wherein: the successive washing operations are carried out with a washing liquid the content of the substance to be eliminated therein decreasing from the first washing operation towards the last washing operation; a small quantity of liquid rich in the substance to be eliminated is removed from the washing liquid used during the first washing operation and an equivalent amount of the liquid free of the substance to be eliminated is introduced into the washing liquid used during the last washing operation; during each washing operation a substantial quantity of washing liquid is used, the greater quantity of this liquid being recovered and with the exception of the first washing operation, a small quantity of this washing liquid is transferred into the washing liquid corresponding to the washing operation at the immediately lower level whereby the content of the substance to be eliminated is maintained constant in each washing operation. The process may be carried out continuously or discontinuously.