APPARATUS AND PROCESS FOR CLEANING POLLUTED GROUND MATERIAL

摘要

The present invention concerns an apparatus and a process for cleaning polluted ground material which is finely divided in a first step and heat-treated in a second step. The apparatus for cleaning polluted ground material has a pre-dividing device (4 5, 6) and a heat treatment station. To provide an apparatus and a process of the above-indicated kind which permit highly efficient removal of volatile substances from the ground material at a comparatively low energy consumption and at low cost it is proposed in accordance with the invention that in regard to the process the ground material is heated in the second step without contact with an open flame by way of heat exchangers to a temperature above the boiling temperature of water and below a temperature of 400.degree.C and then the heated fine-grain ground material is exposed to hot, possibly superheated steam which removes the volatile constituents from the ground material grain. In regard to the apparatus it is proposed that the heat treatment station is an evaporator (10) at which there are provided heating devices (21, 11) circulating and conveying devices (11) and at a spacing from an intake of material into the evaporator (10) a steam feed device (12) for the feed of steam which is heated above the water condensation temperature to the ground material which is also heated in that region above the condensation temperature.