Heat treatment of metal castings and in-furnace sand reclamation

Abstract

The method and apparatus for reclaiming substantially pure sand from a heat treating furnace; wherein a casting with sand core and/or sand mold, comprising sand bound by a combustible binder, attached thereto is introduced into the heat treating furnace; or, wherein portions of sand core and/or sand mold that are not attached to a casting are introduced into the heat treating furnace. Wherein, the reclaiming within the furnace is carried out, in part, by a fluidizer that promotes binder combustion by one or more process of agitating, heating, and oxygenating. Wherein, the characteristics of the reclaimed sand are selectively controlled by controlling the dwell time of the sand within the heat treating furnace.

We claim:  
     
         1 . An apparatus for heat treating a casting with sand core, comprising sand bound by a combustible binder, attached thereto and for reclaiming sand from the sand core, said apparatus comprising: 
 a furnace for receiving a casting therewithin; furnace heating means for heating said furnace; and    means for agitating portions of sand core within said furnace.    
     
     
         2 . An apparatus for heat treating a casting with sand core, comprising sand bound by a combustible binder, attached thereto and for reclaiming sand from the sand core, said apparatus comprising: 
 a furnace for receiving the casting therewithin;    furnace heating means for heating said furnace;    means for loosening portions of sand core from the casting; and    means for reclaiming, within said furnace, sand of loosened portions of sand core, wherein said means for reclaiming comprises, at least, a means for agitating loosened portions of sand core.    
     
     
         3 . A method for heat treating a casting with sand core, comprising sand bound by a combustible binder, attached thereto and for reclaiming sand from the sand core, said method comprising the following steps: 
 introducing the casting into a furnace;    heating the furnace; and    agitating, within the furnace, the sand core.    
     
     
         4 . A method for heat treating a casting with sand core, comprising sand bound by a combustible binder, attached thereto and for reclaiming sand from the sand core, said method comprising the following steps: 
 introducing the casting into a furnace;    heating said furnace;    loosening portions of sand mold from the casting while the casting is in said furnace; and    reclaiming, within said furnace, sand of loosened portions of sand mold, wherein the step of reclaiming includes, at least, agitating the loosened portions of sand mold.