The present invention relates to a device for extracting cakes resulting from pressurized filtration from a sealed tank (1) in which rotary filters (2) are provided, the tank being provided with a hopper (1b) for recovering solid particles and having an extension, in the lower portion thereof, in the form of a hatch (10) defined between at least two temporary blocking members (11, 12), characterized in that each temporary blocking member includes a rotary shaft (100) transversally arranged in the hatch and bearing at least one set (101, 102, 103) of two diametrically opposite radial fins having a global surface substantially corresponding to the cross-section of the hatch (10) and optionally at least one set of two radial forks (104, 105), as well as peripheral sealing means(102) mounted on the inner wall of the hatch opposite the end edge of said fins. The invention also relates to an associated extraction method.