In order to obtain a cake of solid particles recovered from suspensions in a liquid, the particles accumulating behind a filter (15) that the liquid penetrates, the connection to a liquid inlet duct (28) into a cylindrical chamber (30) comprises a diffusor (29) that has divergent channels (31) for expanding the flow and rendering the speed and rate of flow uniform in the section of the chamber (30), promoting in particular the peripheral flow, such that a cake having uniform properties is obtained.
