Apparatus for extracting components of solids by means of a liquid

Apparatus for extracting components of solids, by means of a liquid contacting the solids in counter-current flow, comprising:

• a rotating drum which comprises an outer casing, impervious to the liquids, having the shape of a body of revolution, an inner casing substantially impervious to the liquid, concentrically arranged inside the outer casing, having also the shape of a body of revolution, and defining a central axial channel, the axial length of the drum being much greater than the diameter of the outer casing, a plurality of radial walls, angularly spaced from one another, pervious to the liquid, extending axially along said drum, substantially between the inner casing and the outer casing, said radial walls and said inner and outer casings substantially defining generally axial compartments for the solids, said compartments extending substantially from one end to the other of the drum and having, along a cross section at right angle to the drum axis, the general shape of a truncated circle sector the apex of which merges with the drum axis;
• solids supply means for supplying a portion of solids to said compartments at one end of said drum;
• removal means for removing another portion of solids from said drum at the other end of said drum;
• liquid supply means for supplying liquid into the part of said compartments situated underneath the longitudinal axis of said drum, at said other end thereof;
• and
• overflow means for allowing the liquid to overflow out of said drum at said first end of said drum.