The invention relates to an apparatus for the treatment of spent material said treatment including the desolventisation and toasting of said spent material (DT) to yield desolventized spent material and/or the drying and cooling of said desolventized spent material (DC) to yield meal and/or their combination (DTDC), said apparatus being made of stacked trays supporting said spend material said apparatus being equipped with means to provide at least one fluid phase going through said spent material, wherein at least a portion of the said at least one fluid phase is pulsed through said spent material.