| 摘要 |
PURPOSE: To obtain fine metallic powder at a good yield with use of inexpensive refractories and a small amt. of gas of an ordinary pressure by combining a refractory molten metal pipe and a specific gas injection jig at the time of producing the fine metallic powder by an atomization method. CONSTITUTION: A gas atomizing nozzle is constituted by providing the molten metal pipe 2 of a cylindrical shape with the annular gas injection jig 1 around this pipe in tight contact state therewith. The shape at the bottom end on the outlet side of the molten metal pipe 2 is a horizontal plane having no difference in level. The outlet shapes of plural pieces of gas injection holes 3 for injecting gas jets in an inverted circular conical form from the circumference of the molten metal flow of the injection jig 1 on the outlet side of the molten metal pipe 2 are circular. The axial central lines 8 of the injection holes 3 converge at a point 7 on the axial central line 6 in the lower part of the molten metal pipe 2 and intersects therewith at an angleα. The volume V of the space enclosed by the curved surface 5 of a virtual inverted circular cone smoothly connecting the axial central lines 8, the outside surface of the molten metal pipe 2, its extension surface, the side end faces of the injection holes 3 of the gas injection jig 1 and their extension surfaces satisfies the equation. Dn is the diameter (mm) of the virtual circle smoothly connecting the central points at the circular sections of the injection holes in the outlets of the injection holes 3.
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