Abstract: A filter apparatus comprises a plurality of rod-shaped filter elements disposed within a cylindrical vessel on at least one circular array concentric with the vessel axis, and extending parallel to the vessel axis, said filter elements being mounted in one of the vessel end walls and drained through this vessel end wall. Rotatably mounted in the opposite vessel end wall is a rotor comprising a plurality of agitator elements extending radially spaced from and parallel to the filter elements. The filter elements are provided with individual filtrate drains adapted to be individualy monitored to ascertain the quality of the filtrate. Each filtrate drain may be provided with a valve operable to deactivate the associated filter element in the case of damage thereto.