JPS62278208A - Ring nozzle for producing metallic powder - Google Patents

Abstract

PURPOSE:To reduce energy loss and to stably atomize a molten metal by incorporating a prescribed flow uniformizing ring and a prescribed flow regulating ring into a ring nozzle so as to form a uniform film of the molten metal. CONSTITUTION:A molten metal introduced 12 into a ring nozzle from the introducing holes 5 under high pressure flows into four or more dividing holes 1 pierced in a flow uniformizing ring 3. The molten metal is then introduced into divided chambers 7 and flows into flow regulating holes 2, where the flow directions of the molten metal are changed and the flows are finely divided and regulated. The number of the flow regulating holes 2 is >=2 times the number of the dividing holes 1. The flows are made uniform through a flow regulating zone 11 between a flow regulating ring 4 and the body of the nozzle and jets out of jet holes 13. A jet film having the shape of an inverted cone is formed with high uniformity over the whole circumference, so the molten metal is stably atomized with a reduced energy loss.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a spraying device, in particular a spray nozzle, for producing powder from molten metal.

[Conventional technology]

When molten metal is sprayed using a ring nozzle, the most important thing is the water film formed by the water jet ejected from the nozzle, and the properties of the resulting metal powder are influenced by the properties of this water film. Especially when trying to obtain powder with low apparent density, in the entire circumferential direction of the ring nozzle,
A water film as uniform as possible is required. In the past, various spray nozzles for producing metal powder have been proposed, but among them, a spray device equipped with a dynamic pressure control ring and an adjustment guide has been proposed to obtain a uniform water film (Japanese Patent Publication No. 43 -63
89). In addition to this spray device, there is also a device that converts the jet liquid emitted from a plurality of pencil-type spray nozzles into an inverted conical water film using a creeping guide (Japanese Patent Publication No. 52-19540).
) etc. have been proposed. However, in a spray device equipped with a dynamic pressure control ring and an adjustment guide, when high-pressure water is introduced from one or two high-pressure pipes, this high-pressure water is decelerated once by the dynamic pressure control ring and uniformly After the water has been brought to a certain pressure, the water is ejected from the spout, but in this case, a uniform water flow cannot be achieved in the chamber on the spout side.

This non-uniformity remains even in the high-speed jet ejected from the jet nozzle. In other words, when the width of the gap between the dynamic pressure control ring and the ring nozzle body is 0.2+ns+ or more, the water flow of high-pressure water introduced from one or two directions is strong only in the direction of introduction, and the resulting water film is The focal point is not a point, but a long figure 8-like shape perpendicular to the direction of introduction.

In the method using a dynamic pressure control ring, in order to obtain uniformity of water flow, the width of the gap must be 0.2 mm or less;
If it is less than 21, the resistance due to the dynamic pressure control ring will increase, and the pressure loss will be large (approx.
This results in a loss of 0 kg/crII or more. In addition, the dynamic pressure control ring may be deformed due to not only the pressure loss but also the pressure difference before and after the dynamic pressure control ring, causing the inside of the ring to become clogged and possibly breaking the nozzle or pump.

Such non-uniformity of the water flow coming from the high-pressure water introduction direction can be improved by increasing the ratio of the cross-sectional area of the high-pressure water inlet to the cross-sectional area of the spout, but if the daily new area of the jet is constant. In this case, there is a limit to the inlet cross-sectional area due to the size of the nozzle, etc.
There are many practical problems. On the other hand, in a spray nozzle that does not rectify the flow inside the spray nozzle, but uses a creeping guide to turn the injected impulse into an inverted cone-shaped water film, the energy loss is large because the direction of the high-speed jet is changed by the creeping guide. , there are problems such as a decrease in the ability to powder the molten metal.

[Problem that the invention seeks to solve]

In order to solve the technical problems with the conventional ring nozzles, the present inventors investigated various spray nozzles that were as uniform as possible and had less energy loss. The present invention was completed based on the discovery that the objective could be achieved by installing the following.

[Means to solve the problem]

The present invention provides four or more dividing holes and a number of dividing holes in the direction of changing the flow direction of the spray medium flowing out from the dividing holes, from the time the spray medium is introduced into the spray nozzle until the spray medium reaches the jet nozzle. This is a ring nozzle for producing metal powder, characterized in that it is provided with a countercurrent ring and a rectifier ring, each having at least twice the number of rectifying holes.

[Effect]

Referring to FIG. 1, the present invention will be described in further detail as follows. The inside of the nozzle has a countercurrent ring (2) and a rectification ring (2) which characterize the present invention, and these allow the inside of the nozzle to be divided into four chambers. For purposes of explanation, the order in which high-pressure water flows through this chamber is high-pressure water inlet ■, high-pressure water guide chamber ■, and divided chamber ■
, rectification chamber (■), and pre-ejection chamber (■).

First, the high-pressure water introduced into the nozzle from the high-pressure water inlet (2) enters the high-pressure water introduction chamber (2) and is guided around the entire circumference. Then, it passes through the dividing hole (■) provided in the countercurrent ring (■) and is led to the dividing chamber (■). In this case, there are 4 to 1 dividing holes at equal intervals in the same plane at positions different from the high-pressure water introduction direction and the perpendicular direction.
It is desirable to provide two. By selecting the optimal position and number in this way, the strong directional nature of the high aqua regia in the initial introduction direction is canceled out, and the high aqua regia is introduced into the divided chamber (2). Split room■
Although the flow velocity of the high-pressure water introduced into the tank decreases, the uniformity of the flow improves. Furthermore, the high pressure water comes out from the dividing chamber ■ and the dividing hole [1
] is finely divided by rectifying holes ■ that play the same role as
rectified. In this case, it is desirable that the rectifying holes (2) be located in a direction perpendicular to the dividing hole [1] and at a different position from the same axis, and that the number of rectifying holes (2) be at least twice the number of dividing holes (2).

It is necessary to design the total membrane area of these high-pressure water inlet (■), dividing hole (■), and rectification hole (■) to be approximately equal, thereby creating a structure with less pressure loss and a greater uniformity effect on the water film. A ring nozzle is obtained.

Next, the high-pressure water that is finely divided by this rectifying hole ■ is
The liquid is guided to the rectifying chamber (2), the speed is reduced again, and the liquid is guided from the rectifying band (0) between the rectifying ring (2) and the nozzle body to the ejection front chamber (2). The cross-sectional area of this rectifying zone (2) should be approximately equal to the introduction of high-pressure water, and the width of the gap should be 0.5 to 1 mm in order to reduce the pressure and improve the rectifying effect.

As mentioned above, the high-pressure water introduced into the high-pressure water introduction chamber ■ from the high-pressure water inlet ■, passed through the countercurrent ring ■, the rectification ring [4], and led to the pre-jet chamber ■. The initial strong directionality in the water is canceled out, resulting in a uniform water flow in the entire circumferential direction. The water flow that has been made uniform before the spout 0 in this manner is ejected from the spout 0, forming an inverted conical water film water jet that is highly uniform around the entire circumference. This stabilizes the water film, increases the concentration of the water jet, and increases the energy efficiency of the nozzle. That is, the energy of the water jet is effectively used to deform and cool the molten metal, and the powder obtained using this water film is made into fine particles.

[Example, comparative example]

To confirm uniformity using the ring nozzle of the present invention shown in Fig. 1, the cross-sectional area of the spray port [phase] was made equal to the cross-sectional area of the high-pressure water inlet (■), and the rectification zone gap 0 was set to 0.5...m. 4 people poured high-pressure water from the high-pressure water inlet ■.

At this time, since the cross-sectional area of the jet nozzle 0 and the high-pressure water inlet ■ are made equal, the pressure appearing on the pressure gauge connected to the high-pressure water inlet ■ is mostly due to the resistance of the piping and the resistance inside the nozzle, that is, the rectifier ring. This can be considered to be due to the resistance caused by ■ and the rectifier ring ■. As a result of the test, this pressure was 21kgf/-
Met. In addition, the water flow ejected from the ring nozzle was uniform and stable.

In contrast, as a comparative example, a ring nozzle of the same type as in Japanese Patent Publication No. 43-6389 was used, and the dynamic pressure control ring clearance, which corresponds to the rectifying band clearance of the present invention, was set to 0.5 to 0.31. Similarly, the pressure and the uniformity and stability of the ejected water stream were observed. The results are shown in Table 1 for comparison.

Table 1 Furthermore, using the ring nozzle of the present invention and the ring nozzle of the comparative example, the ejection pressure was set to 150 kgf/cnl, and C
A molten metal of u-10XSn alloy was atomized with a molten metal diameter of 8 mmφ.

Table 2 shows a comparison of the characteristics of the powder obtained by this atomization.

Table 2 As shown in Table 2, when the ring nozzle of the present invention was used, the particle size distribution shifted to the finer side compared to the comparative example, and the apparent density decreased with each particle size, indicating the effectiveness of the present invention. It is shown.

〔Effect of the invention〕

As described in detail above, the ring nozzle incorporating the countercurrent ring and the rectifying ring of the present invention is an industrially useful invention as it can provide a uniform water film and perform stable atomization with little energy loss.

[Brief explanation of drawings]

FIG. 1 is a cross-section of a ring nozzle incorporating the counterflow ring and rectifier ring of the present invention. FIG. 2 is a plan view of the countercurrent ring. ■Divided hole ■Rectification hole ■Counterflow ring ■Rectification ring
■High pressure water inlet ■High water pressure introduction chamber ■Divided chamber ■Rectification chamber ■Pre-spout chamber
＠Adjustment guide・0 rectification zone 0 high pressure water introduction direction
0 spout

Claims (2)

[Claims] (1) After the spray medium is introduced into the spray nozzle until it reaches the spout, there are four or more dividing holes [1] and dividing holes [1].
] A flow equalizing ring [3] and a flow straightening ring [4] are provided in which the number of straightening holes [2] is twice or more the number of dividing holes, and the straightening ring [4] is provided in a direction that changes the flow direction of the spray medium flowing out from the A ring nozzle for metal powder production featuring: (2) The ring nozzle for producing metal powder as set forth in claim 1, wherein the flow equalizing ring [3] and the adjusting ring [4] are integrally constructed.