High-concentration mixer for producing a cellulose suspension having a high cellulose concentration

A high-concentration mixer for producing a homogeneous suspension of cellulose in an aqueous solution of a tertiary amine oxide, comprising a stationary container and an agitator arranged in a container axis, which agitator is connected to a motor via a flange provided in the region of the container bottom, which motor is designed for rotationally driving the agitator for mixing the suspension provided in the container, wherein the agitator has at least one helical coil which brings about a vertical downward flow of the suspension in the centre of the container and a vertical upward flow of the suspension in the region of the container wall, characterized in that the flange comprises at least one blade provided on its circumference, which is designed for wiping the suspension from the container and for supporting the vertical upward flow of the suspension in the region of the container wall, and that a spacer is provided between the container bottom and the flange, which spacer ensures a gap of a substantially consistent width between the container bottom and the flange.