LOW FLOW NOZZLE AND METHOD FOR THERMAL SPRAYING FOR ITS FORMATION

摘要

PURPOSE: To provide a nozzle which pours molten metal out of a crucible, pours out the molten metal at a lower flow rate than heretofore and does not give rise to freeze-off. CONSTITUTION: The nozzle 21 is fitted into the bottom of the crucible 20 and is supported by a step 23 disposed at the crucible bottom. An insert 27A supported by a step 22 is fitted into the nozzle. The bore of this insert and the bore of the nozzle constitute a concentric circular shape in an axial direction and the ratio of the diameter of the bore of the insert to the length thereof is preferably set at 2.7 so as to obtain the max. flow rate. The downstream end of the insert bore is provided with a flow orifice 26 of a trapezoidal shape which flares to the position in contact with the nozzle wall. The bore of the nozzle is expanded with respect to the bore of the insert, by which the occurrence of the freeze-off is substantially prevented.