Method of and apparatus for classifying refuse

An apparatus for treating refuse consisting of light and heavy fractions, said apparatus comprising:

• a housing having an entrance port and defining a generally closed chamber;
• conveyor means for introducing a stream of raw and uncomminuted refuse into said housing through said port at a predetermined velocity in a predetermined generally horizontal direction so that said stream drops in said chamber along a path;
• a return conduit having an outlet end in said chamber at one side thereof and an inlet end in said chamber at the opposite side thereof, said inlet end being directed in said predetermined direction at said outlet end;
• blower means for circulating air in a closed circuit in said conduit and through said chamber in a generally horizontal flow direction generally perpendicular to said path and opposite said predetermined direction;
• means for withdrawing portion of the air from said circuit outside said chamber, for filtering said portion of air, and for releasing said portion of air to the atmosphere;
• a continuous sieve surface in said chamber extending perpendicularly to said flow direction and lying directly in front of said inlet end, whereby air is aspirated through said sieve surface and a portion of said light fraction adheres thereto;
• means for continuously vertically displacing said surface;
• means for stripping said portion from said surface at a location in said chamber vertically offset from said inlet end;
• means relatively close to said sieve surface for collecting the remainder of said light fraction;
• and
• means relatively far from said sieve surfface for collecting said heavy fraction.