The invention relates to a device for the transfer between a solid matter and a liquid, comprising an outer drum and a perforated inner drum, means for commonly rotating the drums, and means situated inside the inner drum for moving the solid matter. In between the two drums, a number of troughs are formed which, during the rotation of the drums, bring up liquid and pour it out higher up through the inner drum. Along the front rim of each trough, the drum is provided with a drain opening, opposite to which means are provided for preventing, when the drain opening, during the rotation of the drums, is at the bottom, the penetration of solid matter through said opening.