Apparatus for cooling castings and for cooling and drying moulding sand

Abstract

An apparatus for cooling castings and cooling and drying moulding sand, comprising a horizontal drum rotatable about its longitudinal axis and having an inlet opening for castings and casting moulds at one end and an outlet opening for castings at the other end. The drum wall first has an impermeable part which is followed by a perforate part for the discharge of moulding sand. An underlying descriptive line of the drum viewed in the direction from the inlet end to the outlet end slopes upwardly at least for a part and this gives rise to several embodiments.

What I claim is: 
     
       1. An apparatus for cooling castings while cooling and drying molding sand, comprising in combination: an elongate, generally horizontal drum having an inlet end and an open discharge end defining a casting discharge mouth;   wall means at said inlet end for defining a restricted opening centered with respect to the axis of the drum, and means for feeding the molding sand and casting contents of molding flasks into said drum through said restricted opening;   said drum including an imperforate section leading from said wall means to adjacent the discharge end of said drum and including at least a terminal region nearest said discharge end which is of frusto-conical section which narrows toward said discharge end;   
     
     
       Said drum also having a perforate section leading from said frusto-conical terminal region of the imperforate section, whereby to discharge sand from said drum before reaching said discharge end of the drum; and means for selectively elevating the discharge end of the drum relative to its inlet end whereby to alter the inclination of said frusto-conical terminal region and thereby alter the residence time of the material passing through the drum.   
     
     
       2. Apparatus according to claim 1 wherein said imperforate section is frusto-conical throughout its length. 
     
     
       3. Apparatus according to claim 1 wherein said imperforate section is cylindrical except for said terminal region thereof. 
     
     
       4. Apparatus according to claim 3 wherein said perforate section is a frusto-conical extension of said frusto-conical terminal region. 
     
     
       5. Apparatus according to claim 3 wherein said perforate section is cylindrical. 
     
     
       6. Apparatus according to claim 1 wherein said imperforate section is of a length at least three times that of said perforate section. 
     
     
       7. An apparatus for cooling castings while cooling and drying molding sand, comprising in combination: an elongate, generally horizontal drum having an inlet end and an open discharge end defining a casting discharge mouth;   wall means at said inlet end for defining a restricted inlet opening centered with respect to the axis of the drum, and means for feeding the molding sand and casting contents of molding flasks into said drum through said restricted inlet opening;   said drum including an imperforate section leading from said wall means to adjacent the discharge end of said drum, and a perforate section at said discharge end, the imperforate section being of a length at least three times that of said perforate section;   said discharge mouth also being centered on the axis of said drum and the cummulative lengths of said imperforate and perforate sections of the drum, the size of said restricted inlet opening and the size of said discharge mouth being such that when said axis is inclined upwardly from said inlet end to said discharge end the lowermost point of said inlet opening lies at an elevated position with respect to the lowermost point of said discharge mouth and at least a portion of said imperforate section immediately adjacent and leading to said perforate section slopes upwardly; and   means for selectively inclining said axis to vary the amount by which said lowermost point of the discharge mouth lies below said lowermost point of the inlet opening whereby to vary the upward slope of said portion of the imperforate section and thereby control the residence time of the material passing through the drum.   
     
     
       8. An apparatus as defined in claim 7 including means for establishing an air flow through said drum from its discharge mount to its inlet opening. .Iadd. 9. Apparatus for cooling castings while cooling and drying molding sand, comprising in combination: an elongate, generally horizontal drum having an inlet end for receiving the contents of molding flasks which comprises molding sand and castings and having an open discharge end defining a casting discharge mouth;   means rotatably supporting said drum for rotation about its longitudinal axis;   said drum having an elongate section extending from said inlet end for mixing the sand and castings as the drum rotates and having a perforate section at said discharge end which is of a length sufficient to allow the sand to separate from the castings by passing through the perforations of said perforate section while said castings pass to and through said discharge opening as the drum rotates;   wall means at said inlet end of the drum for defining an inlet opening centered with respect to the axis of said drum;   said inlet opening being of restricted size with respect to said inlet end of the drum and said drum being shaped to provide at least a portion adjacent said perforate section which defines a bottom line sloping upwardly toward said perforate section to an elevation above the level of the bottom of said inlet end, whereby said sand and castings which are mixed in said elongate section must move upwardly to reach said perforate section;   means for feeding said contents of molding flasks into said drum through said inlet opening to provide a mixture in said elongate section which is of known ratio of sand to castings and of known moisture content; and   means for rotating said drum at a speed related to the slope of said bottom line and to the known characteristics of said mixture so as to dry said sand to a selected moisture content at discharge thereof while discharging said castings at hand-heat. .Iaddend.