Method and apparatus for reclaiming sand

Sand reclaiming apparatus comprising:

• a. a longitudinal drum defining an internal chamber having first and second subchambers, said drum being mounted for rotation about a longitudinal axis;
• b. means for rotating said drum;
• c. an inlet port located at one end of said drum and in communication with said first subchamber;
• d. an inlet chute extending through said inlet port into said first subchamber;
• e. a plurality of I-beams located within said first subchamber and attached to the interior periphery of said drum, said I-beams being spaced circumferentially therein and extending longitudinally of said drum;
• f. a spider located within said first subchamber and dividing said first subchamber into first and second breaking zones, said spider comprising a central hub portion and a plurality of arms spaced around said hub portion and extending radially outwardly therefrom, one end of each of said arms being attached to said hub portion and the other end of each of said arms being attached to one of said I-beams;
• g. a plurality of spikes attached to each of said I-beams within said first breaking zone, said spikes having a generally conical shape and extending inwardly within said drum;
• h. a first sizing screen located adjacent said second breaking zone, said first sizing screen having a generally frustoconical shape and being attached to a first screen frame supported within said drum, said first sizing screen in part defining a grinding zone containing a plurality of grinding balls;
• i. an inner shell located within said second subchamber of said drum, one end of said inner shell being attached to said first screen frame;
• j. a second sizing screen positioned between said inner shell and said drum, said second sizing screen having a generally frusto-conical shape and being attached to a second screen frame supported between said inner shell and said drum;
• k. a plurality of outlet openings within said drum located radially adjacent said second sizing screen;
• and
• l. a plurality of third sizing screens, one of said third sizing screens being positioned across each of said openings.

Method of reclaiming sand from foundry molds and the like comprising the steps of:

• a. feeding the material to be reclaimed into a drum having an internal chamber defining first and second subchambers;
• b. rotating said drum;
• c. passing the material to be reclaimed through a first breaking zone within said first subchamber having projection members located therein;
• d. classifying the material to be reclaimed into a first part consisting of particles having a predetermined first maximum size and a second part consisting of particles larger than said predetermined first maximum size;
• e. passing said first part of material to be ground through a second breaking zone within said first subchamber;
• f. classifying said first part of the material to be ground into a first portion consisting of particles having a predetermined second maximum size and a second portion consisting of oversized particles;
• g. discharging said oversized particles from said drum;
• h. grinding said first portion of said first part of the material to be reclaimed in a grinding zone containing a plurality of grinding balls;
• i. classifying said first portion of said first part of the material to be reclaimed after it has been ground into a finished product having a predetermined third maximum size and oversized particles;
• j. discharging the oversized particles from the drum;
• and
• k. discharging said finished product from the drum.