Process and plant for drying sludge-like materials, especially sludge from wastewater treatment plants, with thermal energy production

摘要

The invention relates to a method for drying pasty materials, in particular sludge from wastewater treatment plants, including a first indirect drying stage (1) supplied with a heat-transfer fluid, which outputs (1a, 1b) pre-dried sludge and water vapour; a step (6) of forming sludge at the outlet of the first stage, and a second stage of drying (7) pre-dried sludge that is heated by means of a heating gas, in particular air, said second stage producing (7b) dried sludge; at least one portion of the dried sludge produced by the second stage is incinerated (23) to produce thermal energy, and at least one portion of said thermal energy is used to heat the heat-transfer fluid of the first drying stage.