Two-stage heat treating decoring and sand reclamation system

A two-stage system for processing metal castings and core sand formed of sand and binder, including a first stage for removing said core sand from said metal castings and heat treating said metal castings, and including a separate, second stage for thereafter reclaiming at least said core sand removed from said metal castings for reuse,

• said system comprising, in said first stage:
• means for conveying said castings and sand in said first stage and including a casting entrance for receiving said castings and a casting exit for removing said castings;
• means for fluidizing and heating said sand in said conveying means of said first stage to a substantially uniform heat treating temperature to thereby cause said castings to be heat treated while at the same time causing said binder in said core sand within said castings to break down such that said core sand is removed from said castings in at least clumps of said core sand and binder;
• said conveying means of said first stage comprising a first heated chamber having a support surface for said castings and a support surface for said sand and a first plenum for directing hot air upwardly through said sand into said first heated chamber and including means for vibrating said conveying means of said first stage to convey said castings and said sand generally from said casting entrance toward said casting exit;
• and
• means for transferring all of said sand from said conveying means of said first stage including said core sand removed from said castings, and including any clumps of said core sand and binder, to said second stage to fully reclaim said core sand for reuse by completely pyrolyzing said binder while said core sand is within said second stage;
• said sand transferring means being in communication with said conveying means of said first stage intermediate said casting entrance and said casting exit;
• said system comprising, in said second stage:
• means for conveying said sand in said second stage and including a sand entrance for receiving all of said sand from said sand transferring means of said first stage;
• means for fluidizing and heating said sand in said conveying means of said second stage to a sand reclamation temperature to thereby cause said core sand removed from said castings in said first stage, and including any clumps of said core sand and binder, to be subjected to heat sufficient to completely pyrolyze said binder in said second stage to cause said core sand to be reclaimed for reuse;
• said conveying means of said second stage comprising a second heated chamber having a support surface for said sand from said first stage and a second plenum for directing hot air upwardly through said sand into said second heated chamber and including means for vibrating said bed of said second stage to convey said sand generally from said sand entrance to a sand exit;
• and
• means for recirculating at least a portion of said sand from said conveying means of said second stage to said conveying means of said first stage after said core sand has been reclaimed for reuse;
• said sand recirculating means being in communication with said conveying means of said second stage generally at said sand exit of said conveying means of said second stage.

A two-stage vibratory system for processing metal castings and core sand formed of sand and binder, including a first vibratory stage for removing said core sand from said metal castings and heat treating said metal castings, and including a separate, second vibratory stage for thereafter reclaiming at least said core sand removed from said metal castings for reuse,

• said system comprising, in said first vibratory stage:
• means for conveying said castings and sand in said first vibratory stage and including a casting entrance for receiving said castings and a casting exit for removing said castings;
• means for fluidizing and heating said sand in said conveying means of said first vibratory stage to a substantially uniform heat treating temperature to thereby cause said castings to be heat treated while at the same time causing said binder in said core sand within said castings to break down such that said core sand is removed from said castings in at least clumps of said core sand and binder;
• said conveying means of said first vibratory stage comprising a first heated chamber having a grid-like support surface for said castings and a support surface for said sand and a first plenum below said grid-like support surface for directing hot air upwardly through said sand into said first heated chamber and including means for vibrating said conveying means of said first vibratory stage to convey said castings and said sand generally from said casting entrance toward said casting exit;
• said vibrating means of said first vibratory stage producing vibratory forces to convey said castings and said sand generally from said casting entrance toward said casting exit;
• and
• means for transferring all of said sand from said conveying means of said first vibratory stage including said core sand removed from said castings, and including any clumps of said core sand and binder, to said second vibratory stage to fully reclaim said core sand for reuse by completely pyrolyzing said binder while said core sand is within said second vibratory stage;
• said sand transferring means being in communication with said conveying means of said first vibratory stage intermediate said casting entrance and said casting exit;
• said system comprising, in said second vibratory stage:
• means for conveying said sand in said second vibratory stage and including a sand entrance for receiving all of said sand from said sand transferring means of said first vibratory stage;
• means for fluidizing and heating said sand in said conveying means of said second vibratory stage to a sand reclamation temperature to thereby cause said core sand removed from said castings in said first vibratory stage, and including any clumps of said core sand and binder, to be subjected to heat sufficient to completely pyrolyze said binder in said second vibratory stage to cause said core sand to be reclaimed for reuse;
• said conveying means of said second vibratory stage comprising a second heated chamber having a support surface for said sand from said first vibratory stage and a second plenum for directing hot air upwardly through said sand into said second heated chamber and including means for vibrating said conveying means of said second vibratory stage to convey said sand generally from said sand entrance to a sand exit;
• said vibrating means of said second vibratory stage producing vibratory forces to convey said sand generally from said sand entrance to said sand exit for recirculating at least a portion of said sand;
• and
• means for recirculating at least a portion of said sand from said conveying means of said second vibratory stage to said conveying means of said first vibratory stage after said core sand has been reclaimed for reuse;
• said sand recirculating means being in communication with said conveying means of said second vibratory stage generally at said sand exit of said conveying means of said second vibratory stage.