JPH0322441B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to molten metal, which is one of the powder manufacturing methods used to manufacture metal powder that is a raw material for powder metallurgy, electrical materials, etc. This invention relates to a spray device for the spray method.

[Conventional technology]

Conventionally, methods for producing powder for powder metallurgy, electrical materials, etc. include electrolytic method, mechanical pulverization method, rotating electrode method,
There are reduction methods, spraying methods, etc., but the spraying method is particularly suitable for mass production and is widely used. As a powder manufacturing apparatus using this spraying method, for example, the one shown in FIG. 1 is known. That is, in FIG. 1, 1 is a tundish, 2 is a molten metal, 3 is a molten metal flow, 4 is a nozzle body, 5 is a metal droplet, and 6 is a molten metal flow.
is a container, 7 is a fluid flow (jet) such as water,
This jet 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 a device, the metal flow is instantaneously dispersed and cooled, so metal powder can be easily produced in large quantities, and the manufacturing cost is therefore low.

The jet of the conventional spray device is formed through a slit formed by a nozzle inner cylinder 8 and a nozzle outer cylinder 9 fitted into the nozzle body 4. The speed of this jet is determined by the slit width W.
Generally, it is set to 0.5 to 0.01 mm. When adjusting this slit width W, please refer to the second
As shown in the figure, this is done by providing a screw at the top and rotating an inner screw 10 to move the inner cylinder up and down. However, this method has the disadvantage that it is difficult to change the slit width W during tapping, and in the event of an accident such as the molten metal flow 3 being blown up, the screw may be damaged.

[Problem that the invention seeks to solve]

This invention solves the problems of the prior art described above, and allows the slit width W to be arbitrarily adjusted even when molten metal is flowing down, that is, when tapping, and prevents accidents such as blowing up of the molten metal stream 3. A molten metal spraying device that is characterized by not being damaged even in the event of a molten metal spraying device was completed after various studies.

[Means for solving problems]

That is, the present invention uses a nozzle with an annular slit to eject water or other fluid, and in an apparatus for spraying and pulverizing molten metal by flowing down the molten metal into the center of the nozzle, concentric slits are used to form the slit. The slit width W is adjusted by moving the nozzle outer cylinder between the nozzle inner cylinder and the nozzle outer cylinder arranged above by rotating an adjustment screw provided at the lower part thereof using a drive device. This is a unique molten metal spraying device.

[Effect]

As shown in FIG. 3, this invention provides a nozzle outer cylinder 9 of a spraying device that forms a slit for ejecting fluid.
By rotating the adjusting screw 11 provided at the bottom of the boiler by rotating a drive device such as a motor, the slit width W can be safely adjusted arbitrarily even during tapping, and the jet speed can be arbitrarily adjusted. , the particle size of metal powder can be adjusted freely.

That is, in the conventional spraying device shown in FIG.
Even if the slit width W is precisely adjusted using the internal screw 10, it is difficult to maintain a very narrow gap of 0.01 mm constant during spraying because the molten metal flow 3
This is difficult due to the effects of radiant heat, fluctuations in fluid pressure, fluid temperature, etc. In the apparatus of the present invention, by adjusting the slit width W using the drive device 2, such as a motor, while monitoring the nozzle back pressure, a constant and arbitrary jet flow velocity can be obtained.

Furthermore, as is clear from FIG. 3, neither the liquid flow nor the powder flow comes into contact with the drive device, and maintenance is extremely easy.

〔Example〕

FIG. 3 shows one embodiment of this invention, and shows the first embodiment of the invention.
The same reference numerals are used for the same components as in FIGS.

In FIG. 3, reference numeral 9 denotes a nozzle outer cylinder, which is movably inserted into the lower part of the nozzle body by means of an adjusting screw 11. A gear 13 is fitted to the lower part of the adjustment screw 11, and a pinion 14 is fitted to the motor 12, so that the rotation of the motor 12 rotates the adjustment screw 11 via these gears. Then, the nozzle outer cylinder 9 moves up and down. As a result, the slit width W can be adjusted, and the nozzle back pressure can be adjusted arbitrarily even during pouring, and the influence of external disturbances such as those mentioned above, such as radiant heat due to the molten metal flow 3, fluctuations in liquid pressure, and liquid temperature. It is possible to always eliminate minute changes in the slit width W due to

FIG. 4 shows the change in nozzle back pressure when molten metal is sprayed using the spray device shown in FIG. 2, and the change in nozzle back pressure when molten metal is sprayed using the spray device of the present invention. 2, A is the experimental data for the spray device shown in FIG. 2, and B is the experimental data for the spray device of the present invention.

However, the molten metal at this time is a copper alloy, the tapping temperature is 1500°C, the diameter of the molten metal flow is 8 mm, and the inner diameter of the nozzle is 25 mm.

As is clear from FIG. 4, it is difficult to maintain a constant nozzle back pressure with the conventional spray device as shown in FIG. It can be seen that it is possible to keep the nozzle back pressure almost constant.

[Effects of the present invention]

The present invention is capable of maintaining a constant nozzle back pressure even when high nozzle back pressure is applied as described above, and also allows the nozzle back pressure to be changed arbitrarily during tapping, for example, 2 tons. One ton of the tap water was sprayed at high nozzle back pressure, and the remaining 1 ton was sprayed at low nozzle back pressure, and the spraying was carried out under two different conditions to produce two types of metal powders with different particle sizes. It also has the characteristic of being easily obtained.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of a metal powder manufacturing apparatus using a spraying method, FIG. 2 is an explanatory diagram showing an example of a conventionally widely used molten metal spraying apparatus, and FIG. Fig. 4 is an explanatory diagram showing an example of the spraying device of the present invention, and Fig. 4 shows the results of investigating the relationship between the nozzle back pressure and the elapse of tap time when molten metal is sprayed using the spraying device of the present invention, and the results under the same conditions. , which shows a comparison of changes in nozzle back pressure when using a conventional spray device. The meanings of the symbols in the figure are as follows. 1... Tandeshushi, 2... Molten metal, 3...
Molten metal flow, 4... Nozzle body, 5... Metal powder, 6... Container, 7... Liquid flow (jet), 8
... Nozzle inner cylinder, 9 ... Nozzle outer cylinder, 10 ... Inner screw, 11 ... Adjustment screw, 12 ... Motor, 13
... Gear, 14 ... Pinion, A ... Nozzle back pressure of the conventional spray device, B ... Nozzle back pressure of the spray device of the present invention.

Claims (1)

[Claims] 1. In a device that uses a nozzle that spouts water or other fluid with an annular slit to spray and powder molten metal by flowing down the center of the nozzle, nozzles arranged concentrically to form the slit are used. The slit width W is adjusted by moving the nozzle outer cylinder between the nozzle inner cylinder and the nozzle outer cylinder by rotating an adjustment screw provided at the lower part thereof using a drive device. Metal spraying equipment.