Patent ID: 6336953
Filing Date: 2002-01-08
Classification: B22F

Abstract:
An apparatus for preparing metal powder, the apparatus including an annular nozzle comprising:a body having a hole for passing a flow of molten metal, a swirling room formed in the body for swirling a cooling liquid around the hole, and an annular slit between the swirling room and the hole for discharging swirled cooling liquid contained in the swirling room toward the flow of molten metal flowing through the hole, and an exhaust pipe extending downwardly from a lower surface of the annular nozzle with the hole having a central axis consonant to that of the exhaust pipe, an end of the exhaust pipe opposed to an end of the exhaust pipe extending downwardly from the lower surface being an open end, wherein the exhaust pipe has a length of â€œLâ€  and an inner diameter of â€œRâ€  and the annular slit has a diameter â€œrâ€ , and wherein the exhaust pipe has the length â€œLâ€  being 3-100 r and the inner diameter â€œRâ€  being 1.5-5 r, and wherein the flow of molten metal passes through the hole and into the exhaust pipe to be surrounded by the discharged cooling liquid in the form of a hyperboloid of one sheet inside the exhaust pipe to be exhausted, and wherein the hyperboloid of one sheet has a pressure reduced by 50-750 mmHg at a point forming a constricted part inside the exhaust pipe.