JPH0757881B2 - Nozzle for metal powder production - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in a nozzle for producing metal powder by a gas atomizing method.

(Prior Art) The gas atomizing method is a method of producing a rapidly solidified powder by impinging a gas stream on a falling molten metal stream to finely divide the molten metal stream and at the same time cooling the molten metal stream with a gas.

In the conventional nozzle for producing metal powder in the gas atomizing method, as shown in FIG. 3, a molten metal dropping port 2 is provided in the center of a nozzle body 1, and the molten metal dropping port 2 is placed on the outer peripheral wall of the molten metal dropping port 2. An annular gas injection port 3 for injecting and concentrating gas toward the center line 1 of the port 2 is provided.

(Problems to be Solved by the Invention) By the way, since the above-mentioned conventional nozzle for producing metal powder does not have a mechanism for adjusting the injection angle of gas, the metal powder having one specification, that is, the metal powder having a certain particle diameter is used. It could only be manufactured. Further, since the gas injection pressure and amount cannot be adjusted, the gas injection pressure and gas amount corresponding to various molten metal flows cannot be set, and therefore the metal powder that can be produced by one nozzle is limited and lacks versatility. Further, the gas is tangentially supplied to one gas chamber 4 to form a swirling flow in the gas chamber 4, and the gas is jetted annularly while swirling from the gas injection port 3, but the gas chamber 4 is large. Therefore, the swirling force of the gas in the gas chamber 4 is weak, and therefore the gas injected annularly from the gas injection port 3 does not swirl sufficiently and the action of finely dividing the molten metal flow is not sufficiently performed. is there.

(Object of the Invention) The present invention has been made to solve the above problems, and it is possible to produce a metal powder having a desired particle size, and to adjust various gas injection pressures and gas amounts to cope with various molten metal flows. Another object of the present invention is to provide a nozzle for producing metal powder, which is capable of giving a sufficient swirling force to the gas injected in a ring shape.

(Means for Solving Problems) A nozzle for producing a metal powder according to the present invention for solving the above problems has a molten metal dropping port at the center of a nozzle body and an outer peripheral side of the molten metal dropping port. In a nozzle for producing metal powder having an annular gas injection port for injecting and concentrating gas toward the center line of the molten metal drop port, the inner peripheral wall portion forming the annular gas injection port is separated from the nozzle body. The nozzle body is detachably fixed to the nozzle body and vertically movable, and the inner peripheral wall portion with the taper angle of the inner peripheral wall is separately prepared, and the outer peripheral wall portion forming the annular gas injection port is separated from the nozzle body. And two gas chambers of a concentric annular shape are provided between the outer peripheral wall portion and the nozzle body and the inner peripheral wall portion, and the passages that connect the two gas chambers are tangential to the inner gas chamber. The passage is the same It is characterized in that it is formed so as to be oriented.

(Function) Since the metal powder production nozzle of the present invention is configured as described above, by vertically fixing the inner peripheral wall portion forming the gas injection port, the gap with the outer peripheral wall portion is adjusted, That is, since the width of the annular gas injection port is adjusted to change the gas injection pressure and the gas amount, various molten metal flows can be accommodated. Also, by replacing the inner peripheral wall part forming the gas injection port with another inner peripheral wall part having a different taper angle and mounting and fixing it, the injection angle of the gas from the annular gas injection port changes, so the molten metal flow The size of the finely divided particles is adjusted, and thus a metal powder having a desired particle size can be obtained.
Furthermore, two concentric annular gas chambers are provided between the outer peripheral wall portion forming the gas injection port and the nozzle main body and the inner peripheral wall portion, and a passage connecting both gas chambers is provided in a tangential direction of the inner gas chamber in all directions. Since the passages are formed in the same direction, when the gas that has entered the small annular gas chamber enters the inner small annular gas chamber through the tangential passage, it makes a strong swirling motion. Therefore, the gas injected annularly from the gas injection port swirls sufficiently, the action of finely dividing the molten metal flow is sufficiently performed, and the cooling by the gas is also very effectively performed, so that the gas having a substantially uniform particle size is obtained. A metal powder is obtained.

(Embodiment) An embodiment of the nozzle for producing metal powder according to the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a longitudinal sectional view, second
The figure is a bottom view. In the figure, reference numeral 1 is a nozzle body, and a molten metal drop port 2 made of a carbon pipe is provided in the center, and only the upper end portion of the molten metal drop port 2 is fitted and fixed in the center of the nozzle body 1. There is. On the outer periphery from the middle height portion to the lower end of the molten metal drop port 2, an inner peripheral wall portion 5 forming an annular gas injection port 3 for injecting and concentrating gas toward the center line 1 of the molten metal drop port 2 is provided. Further separated and fitted, and detachably attached to the central concave portion 1a of the nozzle body 1 with the screw 6.
Moreover, the lock screw 7 is screwed up to the inner peripheral wall portion 5 at an equiangular square position in the center of the upper surface of the nozzle body 1 and fixed. As the inner peripheral wall portion 5, several kinds of inner peripheral wall surfaces 5a having different taper angles are separately prepared. The outer peripheral wall portion 8 forming the annular gas injection port 3 is separated from the nozzle body 1 to separate the nozzle body 1.
It is detachably fixed to. That is, the annular convex portion 8a of the outer peripheral wall portion 8 is fitted into the annular concave portion 1b of the nozzle body 1, and the annular convex portion 8a is fixed to the annular concave portion 1b with the screw 9 screwed from the upper surface of the nozzle body 1. The outer peripheral edge of the outer peripheral wall portion 8 is fixed to the step portion 1c on the lower surface of the outer peripheral portion of the nozzle body 1 with a screw 10 screwed from the lower surface thereof. The annular convex portion 8a of the outer peripheral wall portion 8 forms two concentric annular gas chambers 11 and 12 between the nozzle body 1 and the inner peripheral wall portion 5.
Four passages 13 communicating with 1 and 12 are formed in the annular convex portion 8a in the tangential direction of the inner gas chamber 12. 14, 14 'in the figure
Reference numeral 15 is a gas pipe for feeding an inert gas to the outer gas chamber 11, and reference numeral 15 is a molten metal scattering protection cylinder vertically fixed to the outer peripheral side of the gas injection port 3, that is, the lower surface of the outer peripheral wall portion 8 concentrically with the gas injection port 3. Is. In this example, the taper angle of the inner peripheral wall portion 5a of the inner peripheral wall portion 5 is 35 degrees, and the opening 8b of the outer peripheral wall portion 8 forming the gas injection port 3 is 10R. The gap with the peripheral wall surface 5a is 0.25 mm.

In the metal powder manufacturing nozzle of the embodiment thus configured, the molten metal is made to flow out and fall from the central molten metal drop port 2 and at the same time, the inert gas is jetted and dropped from the gas jet port 3 on the outer peripheral side thereof. A molten metal is concentrated, finely divided, and rapidly cooled and solidified by the inert gas to obtain a metal powder. In the production of this metal powder, when the inert gas is pumped into the small annular gas chamber 11 outside the gas pipes 14 and 14 ', it immediately passes through the four passages 13 and is tangentially directed to the small annular gas chamber 12 inside. The inert gas makes a strong swirling motion in the annular gas chamber 12 as it flows in from. Therefore, the inert gas that is annularly injected from the gas injection port 3 swirls sufficiently, the action of finely dividing the molten metal flow is sufficiently performed, and the rapid solidification by the inert gas is also very effectively performed, so that it is substantially uniform. A metal powder having various particle sizes can be obtained.

In addition, in the nozzle for producing metal powder of the present invention, the lock screw 7 is removed from the inner peripheral wall portion 5, and the inner peripheral wall portion 5 is rotated to move up and down with respect to the concave portion 1a of the nozzle body 1 as appropriate.
Since the gap between the outer peripheral wall portion 8 and the opening 8b is adjusted, that is, the width of the annular gas injection port 3 is adjusted to change the gas injection pressure and the gas amount, various molten metals are fixed. It can be applied to finely divide the flow and rapidly solidify it to make metal powder.

Furthermore, the nozzle for producing metal powder of the present invention has a gas injection port 3
By replacing the inner peripheral wall portion 5 forming the inner peripheral wall portion 5 with another inner peripheral wall portion having a different taper angle of the inner peripheral wall surface 5a, and mounting and fixing the inner peripheral wall portion 5a, the injection angle of the inert gas from the annular gas injection port 3 is changed. Therefore, the size for finely dividing the molten metal flow is adjusted, that is, a large injection angle results in a metal powder having a small particle size, and a small injection angle results in a metal powder having a large particle size. A metal powder having a diameter can be obtained.

(Effects of the Invention) As can be seen from the above description, the nozzle for producing metal powder according to the present invention can give a sufficient swirling force to the gas injected in a ring shape, so that the molten metal flow can be sufficiently finely divided. In addition, rapid solidification by gas is extremely effective, and a metal powder having a substantially uniform particle size can be obtained. Moreover, since the gas injection pressure and the gas amount can be adjusted by adjusting the width of the gas injection port, various molten metal flows can be finely divided and rapidly solidified to produce metal powder, which is versatile. Furthermore, the inner peripheral wall portion forming the gas injection port,
By replacing with a taper angle of the inner peripheral wall surface changed, the gas injection angle is adjusted, and there is an effect that a metal powder having a desired particle size can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the metal powder producing nozzle of the present invention, FIG. 2 is a bottom view thereof, and FIG. 3 is a vertical sectional view showing a conventional metal powder producing nozzle. Is a bottom view thereof.

Claims (1)

[Claims] 1. A metal having a molten metal drop port at the center of a nozzle body and an annular gas injection port for injecting and concentrating gas toward the center line of the molten metal drop port on the outer peripheral side of the molten metal drop port. In the powder manufacturing nozzle, the inner peripheral wall portion forming the annular gas injection port is separated from the nozzle main body to be detachably fixed to the nozzle main body and vertically movable, and the taper angle of the inner peripheral wall surface is changed. An inner peripheral wall portion is separately prepared, and an outer peripheral wall portion forming an annular gas injection port is separated from the nozzle main body and detachably fixed to the nozzle main body, and between the outer peripheral wall portion and the nozzle main body and the inner peripheral wall portion. Nozzle for producing metal powder, wherein two concentric annular gas chambers are provided, and a passage connecting the two gas chambers is formed so that all the passages have the same direction in the tangential direction of the inner gas chamber.