CRUCIBLE FOR MANUFACTURING PT, PD GROUP NOBLE METAL GRANULAR LUMP

摘要

PURPOSE: To protect the body and the nozzle against damage due to heat shock by covering a nozzle having a nozzle hole formed integrally with an inner crucible on the bottom of a double crucible with an outer crucible. CONSTITUTION: A nozzle 5 having a nozzle hole 4 defined by a straight part 4a of 3-6 mm long having inside diameter of 2-7 mm and a tapered part 4b of 10-17 mm long having enlarged inside diameter of 7.3-16.2 mm integral with an inner crucible 1 is formed on the bottom of a double crucible where the inner crucible 1 is covered with an outer crucible 2. Since the inner crucible 1 and the integral nozzle 5 having a low heat shock resistance are covered with the outer crucible 2 having a high heat shock resistance, they are protected surely. Furthermore, clogging due to solidification in the way of flow down can be eliminated because the straight part 4a of the nozzle hole 4 is short. According to the structure, the body and the nozzle are protected against damage due to heat shock surely and a granular mass can be produced smoothly.