JPH0256403B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a metal powder manufacturing apparatus used for manufacturing metal powder that is a raw material for powder metallurgy, electrical materials, and the like. [Prior Art] Conventionally, metal powder manufacturing equipment for powder metallurgy, electrical materials, etc. has been manufactured using electrolytic method, mechanical pulverization method, spray method,
Powder manufacturing equipment using a rotating electrode method or the like is often used, and the spray method is particularly suitable for mass production and is widely used. For example, as shown in FIG. 1, 1 is a tundish, 2 is a molten metal, 3 is a molten metal stream, 4 is a nozzle body, 5 is a metal droplet, 6 is a container, and 7 is a molten metal stream. It is a fluid stream such as water, and this fluid stream is ejected at a high speed, for example, 100 m/s, so as to be focused at an angle θ. When molten metal is sprayed using such an apparatus, metal droplets are instantaneously formed and cooled at the same time, which has the advantage of low manufacturing costs and high productivity. A nozzle body as shown in FIG. 2 is well known as a conventional spraying device. The fluid inlet of the nozzle body is often designed so that the fluid flows in from the tangential direction as shown in Fig. 3, and the fluid exits from the outlet as a swirling jet, so if the angle θ is made smaller, However, a void is formed in the center of the jet, and as a result, the molten metal flow is not sufficiently atomized, resulting in a poor product yield of metal powder. In addition, when the angle θ is increased, an upward flow occurs at the focal point of the jet, which causes the molten metal to be blown up, preventing atomization, and eventually causing the molten metal flow to block the center of the nozzle body, which is a serious drawback. It was hot. [Problems to be Solved by the Invention] The present invention solves the above-mentioned problems of the prior art, and enables the efficient production of metal powder by easily forming a jet that has no pores and does not cause the blow-up phenomenon. The purpose is to provide a metal powder manufacturing device that can produce metal powder. [Means for Solving the Problems] That is, the present invention provides an apparatus for spraying and pulverizing metal by using a nozzle having an annular slit that spouts water or other fluid, and causing molten metal to flow down into the center of the nozzle. In the metal powder manufacturing apparatus, an inflow hole is provided on the side surface of the nozzle so that fluid flows in from two directions, a tangential direction and a normal direction, and a valve is attached to each of the inflow holes to adjust the inflow amount. be. [Function] As shown in Fig. 4, this invention controls the inflow amount of fluid such as water through valves, one in the normal direction and one in the tangential direction on the side surface of the nozzle body from which fluid is ejected. By doing so, a jet with no pores and no blow-up phenomenon is formed, and metal powder can be produced with a high yield. That is, the fluid flowing in from the inflow hole in the tangential direction rotates within the nozzle body, and the fluid flowing in from the inflow hole in the normal direction acts to stop the rotation. Therefore, by adjusting the valves 9 and 10, a jet having a composite vector F of the vector F1 due to the centrifugal force and the vector F2 due to the injection force as shown in FIG. 5 is formed, and the actual injection angle is determined by adjusting the nozzle body. It is characterized by changing the angle from θ to θ ₀ to form a jet free of voids and blow-up phenomenon. Therefore, if the nozzle body angle is manufactured within the range of 15° to 90°, the optimum injection angle, for example, 40°, can be easily obtained by adjusting the valves 9 and 10 without changing the nozzle body angle. . [Embodiment] FIG. 4 is a diagram showing an embodiment of the present invention, and the same reference numerals as in FIG. 3 are used, and the explanation thereof will be omitted. The metal powder manufacturing apparatus of the present invention shown in FIG. 4 has a nozzle body angle of 90 degrees, and has two inlet holes on the side surface of the nozzle body 5, one from the connection direction and one from the normal direction to the valve 9. A valve 10 is provided for fluid inflow. Using this device, a molten copper metal stream was sprayed with a ratio of tangential flow rate to normal flow rate of 3:1, and fine metal powder could be produced at a high yield. Further, when a molten copper metal stream was sprayed by flowing the fluid at the above-mentioned flow rate ratio of 5:1, voids were generated in the center of the jet and only very coarse copper powder was obtained. When the molten copper metal stream was atomized by flowing the fluid at the above-mentioned flow rate ratio of 1:1, a severe blow-up phenomenon occurred and no atomization was possible. Further, when the fluid was flowed at a flow rate ratio of 4:1 and a molten copper metal flow was sprayed, copper powder was obtained which was slightly coarser than when the flow rate ratio was 3:1. The spraying conditions of this example and the powder characteristics (particle size distribution, apparent density, fluidity) of the obtained powder are shown in Table 1. Further, in the apparatus of the present invention shown in FIG. 4, the powder characteristics are also shown in Table 1 as a comparative example when the ratio of the tangential flow rate to the normal flow rate is changed as the spray conditions. As is clear from Table 1, the copper powder obtained using the apparatus of the present invention has a fine particle size and a good yield.

【table】

〔Effect of the invention〕

According to the present invention, fine metal powder can be obtained with a high yield by allowing the fluid to flow in two directions, the tangential direction and the normal direction, and adjusting the respective flow rates using valves.

[Brief explanation of drawings]

FIG. 1 is an overall explanatory diagram showing an example of a powder manufacturing apparatus using the spray method, FIG. 2 is a side view showing the direction of fluid inflow of a conventional nozzle body, and FIG. 3 is a plan view showing the direction of fluid inflow of a conventional nozzle body. FIG. 4 is an explanatory diagram showing an example of the powder manufacturing apparatus of the present invention, and FIG. 5 is an explanatory diagram showing changes in the jet angle of the fluid of the present invention. DESCRIPTION OF SYMBOLS 1... tundish, 2... molten metal, 3... molten metal flow, 4... nozzle body, 5... droplet, 6... container, 7... fluid flow, 8... fluid inlet, 9... valve, 10...
valve.

Claims (1)

[Claims] 1. In a device that uses a nozzle with an annular slit to eject water or other fluid and sprays molten metal down the center of the nozzle to atomize the metal, the side surface of the nozzle has a tangential direction and a normal direction. An inflow hole is provided so that fluid can flow in from two directions,
Metal powder manufacturing equipment characterized by each valve being equipped with a valve to adjust the amount of inflow.