Abstract: The application discloses double-acting pusher centrifuges comprising a rotatable sieve drum (6) which carries out separation of a mixture (17) into liquid and solid matter portion (40) in the form of filter cakes (14, 15). A centrally located pusher floor device, movable to-and-fro along the axis (9) of the sieve drum (6), pushes out alternately to one side and the other by its outer annular region the filter cake (14) deposited since the last clearing of the drum region. The pusher floor is provided at the height of the filter cake with a plurality of axial throughflow openings (12), which are fed through associated radial feeding openings (13) with a mixture. Deflection into the axial throughflow openings takes place automatically according to the resistance at the outlet which is large on the pushing-out side against the filter cake (14) to be moved, while on the opposite side behind the retreating pusher floor an empty space (16) is created into which the mixture can flow.