Process and plant for thermal treatment, in particular for rendering material harmless which is contaminated with pollutants

摘要

In a process for rendering contaminated material harmless, it is proposed, to improve the economics, that the material is, in a sequence of steps, heated in a first step by means of indirect heating while flowing through a degassing stage and is thus at least partially degassed. It is then further heated while passing through a combustion stage with direct heating, higher-boiling or less volatile pollutants being released. The material is cooled further while passing through a cooling stage with direct transfer of heat to cooling air, and finally discharged. Heated cooling air is introduced as secondary air into the combustion stage and the hot exit gas from the combustion stage is used for the indirect heating of the degassing stage. The gas expelled in the degassing stage is introduced into the combustion stage and burned therein at high temperatures with heated cooling air from the cooling stage. <IMAGE>