A device for carrying out mechanical, chemical, and/or thermal processes in a housing (3), comprising mixing and cleaning elements (5) on at least two shafts (1, 2), the mixing and cleaning elements (5) on the shafts (1, 2) meshing with each other and being equipped with disk elements that include kneading bars. The number of disk elements including kneading bars is adjusted to the speed ratio between the shafts.