Particle separation and drying apparatus

Apparatus for performing particle separation from a liquids/solids slurry comprising:

• a partly perforated centrifuge drum for rotating about a vertical axis at a plurality of selected speeds, including a fast speed at which centrifugal effects on material in the drum are substantial so that partly dried solids collect in a substantially cylindrical mass on a side wall of the drum, and a slow speed at which the centrifugal effects on material in the drum are negligible;
• a stripping mechanism which includes an angularly displaceable plough device;
• drive means for displacing said stripping mechanism within the drum when the drum is rotated at said slow speed for dislodging solids which have been built up on the side wall of the drum in said substantially cylindrical form during rotation at said high speed, and said drive means for angularly displacing said plough device within the drum about an axis parallel to said vertical rotational axis of the drum for entering solids which have been built up in said cylindrical form and also for displacing longitudinally of its own rotational axis for advancing along the length of said cylindrical mass of solids;
• means for supplying a washing liquid to the interior of the drum to enable separated solids to be washed;
• means for heating at least a bottom part of the drum on which partly dried solids collect when dislodged by said stripping mechanism from the side wall of the drum, whereby said solids are themselves heated to cause evaporation therefrom of any remaining liquid;
• and
• a plurality of mixing elements carried by said stripping mechanism which, when the plough device has been displaced longitudinally to approximately its fullest extent, are for entering said solids, which have collected on the drum bottom as a result of stripping by said plough device, and for stirring said solids so as to provide a substantial stirring action to maximize exposure of the surface area of the solids to the wash liquid when washing the solids and to the heated parts of the drum when drying the solids.