ELECTROMAGNETIC INDUCTION CASTING APPARATUS

摘要

PROBLEM TO BE SOLVED: To suppress the temperature gradient of an ingot right after solidifying in a conductive bottomless crucible to a low level by forming the upper parts of the crucible as water cooling parts and the lower parts as non-water cooling parts and dividing at least a portion in a longitudinal direction in both of the water cooling parts and non-water cooling parts to a plurality in a circumferential direction by slits in the longitudinal direction. SOLUTION: This apparatus is arranged on the inner side of an induction coil, electromagnetically melts the raw material for melting in the crucible and downwardly draws the melt while solidifying the molten raw material. The longitudinal parts 2a" of the water cooling parts 2a and the longitudinally parts 2b" of the non-water cooling parts 2b are of the same pitch and the corresponding longitudinal parts are integrated to each other. Electromagnetic force acts to maintain the molten metal and the crucible without contact with each other near the boundaries of the water cooling parts 2a and the non-water cooling parts 2b and, therefore, stable casting is made possible. The cooling of the solidified part is suppressed in the non-water cooling parts 2b and even more, the solidified part is positively subjected to heat insulation by induction heating on the inner side of the slits 2b'. The temperature gradient in a temperature region up to 1420 to 1200 deg.C which exert a serious influence on the performance as the solar battery of the silicon ingot is suppressed to the lower level.