Compulsory mixer for continuous as well as batch processing

The mixer comprises a mixing trough (1) and equipped, in this mixing trough two parallel, driven in opposite directions, with helical mixing tools (15) mixing shafts (4). The direction of rotation of the mixing shafts is selected so that the mixing tools between the mixing shafts run up and cause a reverse feed direction along the individual mixing shafts. The mixer further comprises feed means for introducing hörniger (20,21) and possibly fliessiger (22-23) mixture components into the mixing trough. In mixing trough sheet is disposed between the two mixing shafts, a closable bottom emptying (2) which extends (in particular as a rotary slide valve closure) over a majority of the floor length. In the remainder of the floor length, there is another, smaller discharge (3), which is dimensioned or adjustable such that continuous operation of the mixer, it allows for closed main bottom emptying. The aforementioned twin-shaft compulsory mixer can be used with relatively low conversions, equally for batch operation and continuous operation, so that can be transferred depending on the quality and quantity requirements from one to the other operation in the field.