KR20210131787A - Atomizing assembly and metal powder manufacturing device comprising the same - Google Patents

Abstract

According to one aspect of the present invention, a metal powder manufacturing apparatus can efficiently divide molten metal through the minimization of a spray pressure loss of fluids by forming the shortest path in which the fluids are sprayed by a fluid spray nozzle spraying the fluids toward a molten metal solution spray stream using an atomizing assembly with improved atomizing efficiency. According to another aspect of the present invention, in regard to the metal powder manufacturing apparatus including an orifice, a coolant spray nozzle sprays coolant in a fan shape, and coolant spray nozzles provided at different heights have an inclination angle formed with an inner wall of a chamber to be more increased as the coolant spray nozzles are lowered in height, and, accordingly, deviations of a scattering distance of molten metal droplets can be reduced to efficiently manufacture metal powder having uniform qualities.

Description

Atomizing assembly and metal powder manufacturing device comprising the same

One aspect of the present invention relates to a spray assembly for splitting and spraying a molten metal, and a metal powder manufacturing apparatus including the same.

Pure metals (Fe, Co, Ni, Cu, Zn, Al, Ti), alloys (ferrous (Fe) - non-ferrous (Al, Cu, Ni, Co, Ti)), relatively low-melting ceramic powders ( CuO, SnO, PbO, B ₂ O ₃ ) and the raw materials of their complexes are melted at a high temperature to produce a solid powder, usually conventionally known atomization process and centrifugal process are used.

In the former spraying method, for the purpose of manufacturing various pure metals and alloy powders, a raw metal ingot is charged into a crucible in a vacuum or inert atmosphere, melted completely in a high-frequency induction furnace or arc furnace, and the liquid metal passing through the microtubule is cooled. As a method of producing a fine powder form by high-pressure spraying with a medium (N ₂ , Ar, He, air, water or a mixture thereof), when oxidation is a problem in the powder obtained by this method, it is mainly an inert gas (N ₂ , Ar, He) is used, but when there is no oxidation problem, it is manufactured using air, high-pressure water (H ₂ O) or water and gas (air, N ₂ ). Depending on the size, shape and particle size distribution of the alloy powder, different powders are obtained.

These spraying methods are divided into gas spraying and water spraying depending on the type of cooling medium. First, the gas spraying method uses incombustible gas (N ₂ , Ar, He) or air as a cooling medium, so the cooling effect is low. In the case of powder, it is difficult to obtain a homogeneous alloy powder due to micro segregation, and the increase in production cost is a problem because the gas used is relatively expensive.

On the other hand, since the water injection method uses relatively inexpensive water (H ₂ O), it is possible to reduce the production cost of powder products, and since the cooling effect is large, fine segregation can be reduced. There is a problem that the equipment cost is high, and in order to lower the average particle diameter of the metal powder, a method of increasing the water pressure or increasing the water spray nozzle angle was applied. It is very difficult, and there is a problem in that a lot of ultra-fine satellite powder is attached to the surface of the powder to be manufactured.

Recently, interest in the technology is growing as the field of application of metal 3D printing technology has been expanded and its ripple effect is growing. The development of powder materials for printing is actively progressing.

Most of the metal powder used in the 3D printing process is a spherical powder manufactured by a gas atomizing method. This is because the spherical shape has excellent fluidity and is advantageous for uniform application or discharge of the powder layer, and thus the density and mechanical properties of the molded body can be improved.

The metal powder material currently supplied has a very low manufacturing yield and is supplied at a high price. In general, in the case of the metal powder used for 3D printing of the PBF (Power Bed Fusion) method, a spherical powder with a size of 10 to 45 μm is used. On the other hand, in the case of using the general gas atomizing method, a powder having a wide particle size distribution of 10 to 200 μm with a particle size of about 80 μm is manufactured, and among them, a powder having a size of 10 to 45 μm is about 10 to 15%. because it is only

For this reason, a metal powder manufacturing apparatus has been continuously studied until recently, and the market demand for a method for manufacturing a metal powder having an excellent spherical performance and a fine particle size according to the purpose and use of the product continues.

Korean Patent No. 10-1319028

One aspect of the present invention is to efficiently transmit the fluid injection pressure of the fluid injection nozzle to the molten metal to produce a metal powder having a fine particle size by spraying it, while improving the sphericity and cooling rate of the metal powder. The purpose is to provide a device.

One aspect of the present invention is

a hollow tube having a main body and a hollow tube formed inside the main body, the injection tube for spraying the molten metal liquid flowing through the hollow tube to the outside; and

As a fluid injection nozzle to which the injection tube is mounted, the nozzle body and the nozzle including a through hole through which the injection tube can be mounted and a fluid injection part for injecting a fluid into the molten metal liquid injection stem injected from the injection tube. includes,

The injection pipe is a spray assembly having a protruding end protruding outside the through hole through the through hole.

Here, the fluid injection unit may include a fluid supply pipe provided in the nozzle body, and a fluid injection port for ejecting the fluid supplied from the fluid supply pipe to the outside.

At this time, it is preferable that the fluid injection port injects the fluid by the shortest path up to the splitting point where the molten metal liquid injection stem is split.

In addition, the protruding end preferably has an inclined surface in order to provide the shortest path to the fluid injected from the fluid injection port,

The distance between the splitting point and the protruding end is preferably 2mm to 10mm,

The distance between the splitting point and the fluid nozzle is preferably 5 mm to 45 mm.

At this time, it is preferable that the fluid injection port injects the fluid to the molten metal liquid injection stem at an angle of 10° to 80°,

It may further include an injection pipe support provided on the upper portion of the through hole, the injection pipe is mounted on the outside of the main body of the injection pipe when the through hole passes through the injection pipe to adjust the length of the protruding end,

Preferably, the fluid injection port is an annular nozzle surrounding the injection pipe,

Preferably, the protruding end has a guide structure to provide the shortest path to the fluid injected from the fluid injection port.

Another aspect of the present invention includes the spray assembly described above,

a chamber for cooling the fragmented molten metal droplets; and

and a coolant spray nozzle provided on the inner wall of the chamber to cool the split molten metal droplet,

The cooling water jet nozzle is a metal powder manufacturing apparatus including a cooling water jet nozzle for jetting cooling water in a sectoral shape.

The spray assembly according to one aspect of the present invention injects the fluid to the molten metal liquid spray stem in the shortest path, so that the pressure of the injected fluid is effectively transferred to the molten metal stem, the molten metal is excellent in splitting efficiency and the molten metal droplets are fine. It can be split and sprayed.

In addition, the spherical performance of the sprayed metal powder can be increased by spraying the coolant so that the coolant spray nozzle provided in the chamber for cooling the scattered molten metal droplets has a suitable flight distance according to the falling path that varies depending on the diameter of the molten metal droplet. In addition, the jet nozzle injects cooling water in a flat fan-shaped form, so that the cooling efficiency can be improved because the injection area is wider and the cooling water is intensively injected compared to the cone-shaped cooling water injection.

1 is a cross-sectional view showing the structure of a spray assembly, which is an aspect of the present invention,
2 is a cross-sectional view showing the structure of another embodiment of the spray assembly.
3 is a cross-sectional view schematically showing a cross section of an apparatus for manufacturing metal powder, which is another aspect of the present invention;
Figure 4 is a perspective view schematically showing the metal powder manufacturing apparatus of Figure 3;

Prior to describing the present invention in detail below, it is to be understood that the terminology used herein is for the purpose of describing specific embodiments and is not intended to limit the scope of the present invention, which is limited only by the appended claims. shall. All technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art, unless otherwise stated.

Throughout this specification and claims, unless stated otherwise, the term comprise, comprises, comprising is meant to include the stated object, step or group of objects, and steps, and any other object. It is not used in the sense of excluding steps or groups of objects or groups of steps.

On the other hand, various embodiments of the present invention may be combined with any other embodiments unless clearly indicated to the contrary. Any feature indicated as particularly preferred or advantageous may be combined with any other feature and features indicated as preferred or advantageous. Hereinafter, embodiments of the present invention and effects thereof will be described with reference to the accompanying drawings.

In the present specification, the jet nozzle refers to a jet port for jetting steam, liquid, gas, etc. at high speed. When the expression jet nozzle is used, it is broadly interpreted, including nozzles that increase the speed of the fluid by narrowing the cross-sectional area of the pipe, and jets that can spray fluid at high speed, such as a method that sprays fluid by applying pressure.

Atomizing refers to atomizing a liquid by breaking it into small powders, and hereinafter, as an example, by spraying a high-pressure fluid into a molten metal liquid stem to form fine droplets.

The shortest path means the shortest distance that can be connected on a plane or space from one point or region to another point or region, but is not limited to the one shortest path, and is shorter than other general paths; It may be used to mean including paths having a shape close to a straight line.

One aspect of the present invention is an atomizing assembly for splitting a fluid by spraying a molten metal solution. The spray assembly includes a spray tube and a fluid spray nozzle.

1 is a cross-sectional view schematically showing a spray assembly according to an embodiment of the present invention. The injection pipe means a discharge port through which the molten metal flows. The injection tube includes a body in the form of a hollow tube body, and a hollow tube is formed inside the body, and the supplied molten metal liquid is injected through the hollow tube to the outside through the end of the injection tube. The outer diameter of the body may be changed, but is preferably configured to be constant, and the hollow inside may have a constant inner diameter or a structure in which the inner diameter changes including an orifice.

One end of the injection pipe may be connected to the lower part of a vessel or melting furnace for supplying molten metal, and the other end includes a protruding end protruding to the outside, and may spray the molten metal liquid flowing down the hollow through the outlet.

The inner diameter of the injection pipe may be in the range of 1mm to 7mm, preferably 2mm to 5mm, and the outer diameter of the injection pipe is preferably 9mm to 30mm, preferably 10mm to 20mm.

When the diameter of the injection pipe is smaller than the corresponding range, it is advantageous to form a metal powder with a fine particle diameter by spraying the fluid, but the flow rate of the flowing molten metal is small, so the production of metal powder decreases, and the injection pipe by cooling the molten metal There is a problem with a high possibility of clogging or narrowing.

The inner diameter of the injection pipe can be applied differently depending on the composition, temperature, viscosity, and particle size of the target powder to be used, etc. of the molten metal used, but if it is larger than the corresponding range, the flow rate flowing down increases and atomization by the fluid injection nozzle, that is, The efficiency of mizing is lowered, and the cooling efficiency of the powder is reduced, so that the quality of the manufactured metal powder is deteriorated.

The shape of the injection pipe is not limited, but it is preferably a hollow body shape formed in the vertical direction in which the molten metal liquid falls by gravity. Depending on the shape of the injection tube, the efficiency of splitting the molten metal flowing from the discharge port of the injection tube by the fluid injected from the fluid injection nozzle may vary.

The speed and flow rate of the flowing molten metal may vary according to the shape, diameter and length of the injection pipe, and the flow rate of the molten metal may be adjusted according to the viscosity and pressure according to the temperature and composition of the molten metal. The particle size and cooling rate of the manufactured metal powder may vary depending on the above factors.

The fluid injection nozzle has a through hole formed through the nozzle body in the center of the nozzle body, a fluid injection hole is formed around the through hole and injects a fluid to the outside, and an injection tube support is included in the upper part of the through hole can

The fluid injection nozzle is coupled at the bottom of the molten metal supply container coupled to the injection pipe or the injection pipe to spray the fluid against the molten metal liquid injection stem to split it. It is preferable that the through hole has an inner diameter greater than the outer diameter of the injection pipe so that the injection tube can pass therethrough, and the length is made smaller than the length of the injection tube to form the protruding end of the injection tube.

If the length of the nozzle body is longer than the length of the injection pipe and the end of the injection pipe does not protrude, the molten metal liquid is ejected or jumps out from the discharge port of the injection pipe, and the molten metal liquid comes into contact with the vicinity of the fluid injection port. There is a problem that can block the injection hole or change the direction and diameter of the injection hole.

A fluid supply pipe is configured in the nozzle body. The fluid supply pipe is an internal space for receiving or transporting a fluid supplied from the outside, and injects the fluid to the outside through the fluid injection port. The shape of the fluid supply pipe is not limited, but it is preferable to have a shape similar to the shape or arrangement of the injection hole. For example, when the injection hole has an annular slit shape, the fluid supply pipe also has an annular shape.

The fluid injection port is a device that receives a fluid supplied from a fluid supply pipe and injects the fluid, and the shape thereof is not limited. The fluid nozzle may be in the form of a slit or a hole, and is formed along the through hole and around the periphery of the through hole. The distance between the fluid injection port and the outer circumferential surface of the through hole may be 5 mm to 40 mm, preferably 7 mm to 20 mm.

The fluid to which the fluid injection nozzle 12 is injected is not limited, but it is preferable to use a gas, and the gas used is preferably a gas that does not have reactivity with a metal, preferably a gas with low reactivity such as nitrogen or argon. An inert gas is preferred.

When the direction of the fluid injection port is a straight line or molten metal injection stem from which the molten metal flows from the injection pipe, the central axis is disposed below the fluid injection nozzle so as to face the central axis. The angle formed by the direction of the fluid injection port of the fluid injection nozzle 12 with the injection stem is not limited, but is disposed so that the gas is injected toward the direction of gravity while forming an acute angle with the injection stem. The angle between the fluid nozzle and the spray stem is 10° to 80°, and preferably 20° to 60°.

The fluid injected from the fluid injection port is injected toward the molten metal to transmit pressure, and the injection stem is split by the pressure to be atomized in the form of droplets having a fine diameter. The larger the injection angle of the fluid jet port, the larger the collision occurs, and the greater the atomizing effect.

Since the pressure of the fluid injected from the fluid nozzle decreases sharply the farther it is from the injection port, the shorter the distance between the fluid injection port and the splitting point where the fluid comes into contact with the injection stem and the splitting occurs, the better the atomizing efficiency compared to the injection pressure. have. In general, the larger the injection angle, the shorter the distance between the fluid injection hole and the splitting point may be.

The spray assembly may further include an injection tube support capable of adjusting the position of the injection tube and the length of the protruding end when the injection tube and the through-hole of the fluid injection nozzle are coupled.

The injection tube support may have an annular shape having an inner diameter and an outer diameter, and is provided on the upper portion of the through hole and has an outer diameter greater than the inner diameter of the through hole, and the inner diameter of the injection tube support is the same as or similar to the outer diameter of the injection tube, so that friction and support function. The injection pipe support prevents shaking or movement when the injection pipe penetrates the through hole, and the length of the protruding end can be adjusted according to the thickness of the injection tube support.

The length of the protruding end may be 1 mm to 10 mm, preferably 2 mm to 7 mm.

The injection pipe is coupled to the through-hole to inject molten metal, and the fluid injected from the fluid injection hole formed around the through-hole collides at the splitting point of the injection stem to achieve atomization.

The distance between the discharge port of the protruding end of the injection pipe and the splitting point, which is the point at which the molten metal is split by the fluid injection hole of the fluid injection nozzle, may be 2 mm to 10 mm, preferably 3 mm to 5 mm.

The closer the location of the splitting point where the molten metal stem starts to split by the ejection port of the injection pipe and the fluid injection port of the fluid injection nozzle, the better the atomizing efficiency is. A clogging of the outlet may occur due to the rapid cooling of the molten metal stem.

The fluid injected from the fluid injection nozzle is injected in the direction of the fluid injection port, and the location of the splitting point determined by the direction of the fluid injection port and the position of the injection pipe may have an important effect on atomizing efficiency.

With respect to the location of the splitting point, two distances, the distance from the injection pipe discharge port and the distance from the fluid injection port, can affect the atomizing efficiency. The distance from the injection pipe discharge port can affect the temperature of the molten metal, and the distance from the fluid injection port affects the pressure of the fluid causing the splitting, so it is related to the atomizing efficiency.

For effective atomization, the closer the distance between the fluid injection port and the splitting point is, the better, and at this time, it is advantageous that the injection direction of the fluid and the injection stem of the molten metal liquid form a large injection angle.

When the distance between the fluid injection port and the injection pipe is close, the above condition can be easily satisfied. However, depending on the shape of the injection pipe and the shape of the protruding end, there is a problem in that the fluid injected from the fluid injection port by the edge of the protruding end cannot be injected in the shortest path, but collides with the protruding end or is injected in an inefficient path.

In order to maximize atomizing efficiency by overcoming the problems while satisfying the above conditions, an embodiment of the present invention guides the injection path of the fluid to the protruding end of the injection pipe so that the fluid can be injected in the shortest path; For example, it includes an inclined surface, a tapered surface of a form that becomes thinner toward the end, a through hole, or a structure having an arc or a cycloidal curve in cross section.

The inclined surface may include a cone or a partial shape of a truncated cone, and is preferably formed symmetrically with respect to the central axis of the injection pipe. In a cross section cut by an imaginary plane including the central axis of the injection pipe, when the extension lines of both inclined surfaces of the injection tube circumferential surface meet on the central axis and the angle between the extension line and the central axis is called the taper angle, the taper angle is 00° to 90° may be, preferably 10° to 70°, and more preferably 20 to 60°. This may be determined according to the angle of the fluid nozzle, and is preferably made within the range of -10° to +10° from the angle of the fluid nozzle.

If the taper angle is larger than the corresponding range, for example, if the inclination angle is 90 degrees in the form of a hollow tube body without a guide structure, the position and the injection angle of the fluid injection nozzle are limited, so that the molten metal is separated by the injection pipe outlet and the fluid injection nozzle. The distance of the splitting point increases, and when it is formed smaller than the corresponding range, the thickness around the end becomes thinner, and durability and heat resistance are lowered, so that the life of the orifice is short, and there is a problem that it is easy to malfunction.

The injection direction of the fluid injection port is formed adjacent to the inclined surface of the protruding end, and the injected fluid moves along the injection direction. Since it is not fully used for fragmentation, the efficiency of the device decreases.

Conversely, if the injection direction is too far from the discharge port of the protruding end, the moving distance from the fluid injection port to the molten metal increases, and the pressure of the injected fluid rapidly decreases until it collides with the molten metal, making it difficult to form droplets of fine particle size.

2 is a cross-sectional view showing another embodiment of the present side. The guide structure may include a through hole rather than an inclined surface. The guide structure is provided with a tunnel-shaped passage hole through which the fluid can pass at the protruding end of the injection pipe to induce the shortest path for the fluid to move. The hole size of the through hole may be constant, and may include a structure that expands according to the progress direction.

The fluid ejected by this ‹š, Joule-Thomson effect passes through the narrow hole while passing through the passage hole. do. Due to this, since the temperature of the fluid is lowered when it comes into contact with the molten metal, the cooling rate of the molten metal is further improved, and the amorphous ratio of the cooled metal is further increased due to the high cooling rate. This effect can be achieved because the distance between the fluid injection hole and the passage hole through which the fluid injected at high pressure is injected is close, and is maximized when the distance between the fluid injection hole and the passage hole is 10 mm or less, or 5 to 10 mm.

When the guide structure includes a cycloidal curve, in the case of a straight line, it is possible to minimize the loss of kinetic energy of the fluid caused by the difference between the direction of motion of the fluid injected from the fluid injection port and the direction of the surface of the protruding end. Even if the injection direction of the fluid injection unit and the surface of the guide structure are parallel, the injected fluid has a complicated direction. At this time, energy of the fluid may be lost due to collision with the surface of the guide structure, and the atomizing and cooling efficiency of the molten metal is reduced. some are reduced A cycloidal structure may be introduced to minimize such energy loss. A cycloid is a curve formed by the trace of a point on a circle rolling on a plane. The cycloid has a property of providing a faster falling speed than an object that freely falls due to gravity, and the fluid injected from the fluid spraying unit minimizes energy loss along the curved surface of the cycloid and quickly passes through the guide member to break the molten metal. point can be reached. The loss of kinetic energy on the curved surface of the guide structure is minimized, and the speed of the fluid passing through the curved surface is fast, so atomizing and cooling efficiency are increased.

Since the spray assembly according to an embodiment of the present invention has a guide structure such as an inclined surface at the protruding end, the sprayed fluid moves naturally along the inclined surface without colliding with the protruding end, and pressure can be transmitted to the molten metal stem at a short distance, thereby improving the splitting efficiency. do.

When the fluid injection hole of the fluid injection nozzle is perpendicular to the central axis, the injection gases injected from different nozzles collide with each other and the scattering direction of the molten droplets is not constant, so the quality of the metal powder is not good. It is undesirable because there is a possibility that enemies may scatter toward the injection pipe and block or narrow the discharge port.

The fluid nozzle may be configured in plurality and may be arranged in an annular shape around the through hole. The plurality of fluid nozzles may be configured to spray the fluid toward a point through which the spray stem passes. In this case, the metal molten liquid flowing down is scattered into fine molten droplets by the injected gas to form a cone shape and fall into the chamber.

Another aspect of the present invention is a metal powder manufacturing apparatus including a molten metal supply container, a spray assembly, a chamber, and a coolant spray nozzle.

The molten metal supply container 10 means a container containing the molten metal, and an orifice 11 may be provided on the bottom of the molten metal supply container 10 so that the molten metal can flow down in the vertical direction by gravity. have. The type and composition of the molten metal is not limited, and for example, metals with high activity such as Ti and Al may be included.

In addition, a magnetic metal or alloy and a molten metal of a composition for manufacturing the same, for example, Fe-Si-B-based amorphous metal, Fe-Si-BP-based amorphous metal, Fe-Si-B-Nb-Cu-based Metals having a composition for producing iron-based amorphous metal powder such as nanocrystalline metal, Fe-Ni-M (metalloid)-T (other transition metal), etc. may be used, and the molten metal may be cooled and manufactured into soft magnetic amorphous powder. have.

The spray assembly provides a molten metal liquid from a molten metal supply container at a constant flow rate, and includes an injection tube, which is a hollow tube having a hollow tube therein, and a fluid injection nozzle in which the injection tube is mounted, and the spray assembly described above is preferably used. do.

The chamber is a place where the molten metal particles are cooled inside, and is preferably composed of a cylindrical body having a space therein. The chamber 1 is located below the molten metal supply vessel. The shape of the chamber 1 is not limited, but it is preferably made of a cylindrical shape, and the inner diameter of the chamber 1 may be large at the top and smaller toward the bottom. D1/D2, which is the ratio of the inner diameter D1 in the upper part of the chamber 1 and the inner diameter D2 in the lower part of the chamber 1, may be in the range of 1 to 3, preferably 1.2 to 2.5.

The central axis of the chamber 1 may be installed to coincide with the orifice 11 of the molten metal supply container, and the orifice 11 may not coincide with the central axis of the chamber 1 depending on the angle and arrangement of the coolant injection nozzles. It may be, and the central axis of the chamber (1) may be configured obliquely to form a constant angle, not parallel to the vertical direction.

The length of the chamber 1 is preferably in the range of 1 to 5 times the inner diameter of the upper part of the chamber 1, preferably 1.5 to 4 times, in order to secure the distance at which the flowing molten metal scatters and improve the spherical performance. range is good.

If the length-to-diameter ratio of the chamber 1 is out of the corresponding range, the distance between the installation heights of the cooling water injection nozzles 20 increases, and the range in which the scattering distance of the molten metal droplets can be adjusted by adjusting the angle of the cooling water injection nozzle is narrowed or melted. As the distance between the metal and the cooling water spray nozzle increases, the molten metal droplets may be cooled before they become spherical, which may reduce the cooling efficiency.

If the diameter of the upper and lower parts and the length ratio of the chamber are within the corresponding range, cooling by cooling water can be intensively performed in the lower part of the chamber, thereby increasing the cooling efficiency of the molten metal.

The cooling water injection nozzle is an injection port disposed on the inner surface of the chamber 1 to inject cooling water for cooling the molten metal that has been turned into droplets. As the coolant spray nozzle, a jet nozzle may be used to spray coolant at high speed.

The uppermost coolant spray nozzle among the coolant spray nozzles provided on the inner wall of the chamber is referred to as the first coolant spray nozzle 21, and the height at which the first coolant spray nozzle 21 is positioned is defined as the first height. The first coolant spray nozzle 21 may be a single coolant spray nozzle, and may include a plurality of coolant spray nozzles having the same first height.

Among the coolant injection nozzles located at a height lower than the first height, the coolant injection nozzle having the highest position is called the second coolant injection nozzle 22, and the height at which the second coolant injection nozzle 22 is located is called the second height. define. The second coolant spray nozzle 22 may be a single coolant spray nozzle, and may include a plurality of coolant spray nozzles having the same second height.

Similarly, the third height, the fourth height, and the third coolant spray nozzle 23 and the fourth coolant spray nozzle 24 may be defined. Among the coolant injection nozzles located at a height lower than the (n-1)th height, the coolant injection nozzle having the highest position is called the nth coolant injection nozzle, and the height at which the nth coolant injection nozzle is located is defined as the nth height. .

The inclination angle can be interpreted as meaning an angle formed by the coolant spraying direction of the coolant spraying nozzle in a vertical direction with the inner wall of the chamber. It can be interpreted as an angle formed by a straight line of

The inclination angle of the first coolant spray nozzle 21 is referred to as a first inclination angle, and the inclination angle of the second coolant spray nozzle 22 is referred to as a second inclination angle. The inclination angle of the coolant spray nozzle 24 is referred to as a fourth inclination angle, and the inclination angle of the nth coolant spray nozzle is referred to as an nth inclination angle.

When there are a plurality of first coolant spray nozzles 21 positioned at the first height, all of the plurality of coolant spray nozzles may have the same first inclination angle or may have two or more first inclination angles. The arrangement of the cooling water jet nozzles 20 is not limited, but it is preferable for uniform cooling of the metal powder to be rotationally symmetric with respect to the central axis or to maximize the distance between the cooling water jet nozzles 20 .

For example, it is preferable that the two coolant spray nozzles 20 face each other with respect to the central axis, and the three coolant spray nozzles 20 form an angle of 120 degrees with respect to the central axis and are disposed in the form of an equilateral triangle. . In one embodiment of the present invention, the cooling water injection nozzles 20 are symmetrically disposed with respect to the central axis.

The coolant injection nozzles having different heights may be alternately disposed as shown in FIG. 2 . In the embodiment shown in FIG. 2 , the first coolant spray nozzle 21 and the second coolant spray nozzle 22 are alternately arranged, and the second coolant injection nozzle 22 and the third coolant injection nozzle 23 are alternately arranged. do.

The coolant spray nozzle 20 sprays coolant toward the central axis of the chamber 1 , and the spray direction of the nozzle has an inclination angle. The inclination angle may be increased as the height of the coolant injection nozzle decreases. The first inclination angle is 10° or more, and is made up of 60° or less, preferably in the range of 10° to 30°. Thereafter, the second inclination angle is the same as or greater than the first inclination angle, and the difference from the first inclination angle may be 0° or more and 30° or less, and preferably it is in the range of 5° to 15°.

The third inclination angle may be the same as or greater than the second inclination angle, and the difference from the second inclination angle may be 0° or more and 30° or less, preferably in the range of 5° to 15°.

Assuming that the first inclination angle of the first coolant injection nozzle 21 with the inner wall of the chamber 1 is θ11 and the nth inclination angle of the nth coolant injection nozzle is θ _{1n , θ 11} ≤ θ for n greater than 2 ₁₂ … A relationship such as ≤ θ _1n may be established, preferably θ ₁₁ < θ ₁₂ < … It is good that the relation of < θ _{1n holds.} The n-th inclination angle is equal to or greater than the n-1th inclination angle, and the difference from the n-1 inclination angle may be 0° or more and 30° or less, and preferably ranges from 5° to 15°.

The coolant spray nozzle 20 has an inclination angle, and a different flight distance may be provided according to the diameter of the metal droplet scattered by the fluid spray nozzle 12 by spraying the coolant. The larger the diameter, the larger the mass of the scattered molten metal droplets, the greater the kinetic energy and the less resistance of the fluid, the closer the flight path to the direction of gravity. It has a flight path that spreads out with a large jet angle with the direction of gravity under the resistance of

When the coolant is sprayed in the horizontal direction, the flight distance of the large-diameter droplet becomes shorter, and when the coolant is formed only on the inner wall of the chamber 1 , the flight distance of the large-diameter droplet becomes longer. When the coolant is injected at a predetermined angle with the inner wall of the chamber 1 toward the central axis, the flight distance of the large-diameter droplet and the small-diameter droplet can be adjusted.

If the flight distance is too short, the spherical performance is poor because the spheroidization of the particles due to the surface tension is not performed well. Since this is necessary, efficient production of metal powder can be achieved by adjusting the angle and installation position of the coolant spray nozzle 20 .

The arrangement in which the inclination angle increases as the height decreases has the effect of narrowing the interval between the stages of the coolant sprayed from the coolant spray nozzle as it approaches the central axis of the chamber 1 . A metal droplet having a larger diameter has a flight path closer to the central axis, so it passes through a plurality of cooling water layers at a high speed and has a high cooling rate, thereby increasing cooling efficiency.

The inclination angle of the coolant spray nozzle 20 may be adjusted. In the case of producing powder with different properties from molten metal of a single composition or in case of changing the composition of molten metal to produce powder with the same or better properties, the molten metal liquid by adjusting the spray angle of the coolant It is possible to control the enemy's scattering distance and cooling rate, and to form a powder with a higher amorphous ratio or spherical performance. The adjustment range of the inclination angle may be made in a range of 30 degrees vertically.

2 is a perspective view showing a coolant injection angle of a chamber according to an embodiment of the present invention. The coolant spray pattern of the coolant spray nozzle 20 installed on the inner wall of the chamber is indicated by a broken line. The cooling water injection shape of the cooling water injection nozzle 20 and the injection angle of the cooling water injected from the cooling water injection nozzle 20 vary depending on the height of the cooling water injection nozzle.

The coolant sprayed from the spray nozzle is sprayed in the form of a flat sector, and the central angle of the sector is defined as the injection angle. The spray angle may range from 30° to 130°, preferably from 35° to 110°, and more preferably from 40° to 90°.

The fan-shaped injection of the cooling water spray nozzle 20 concentrates the cooling water compared to the cone-shaped injection, so the cooling water is sprayed at a high density, so the cooling efficiency is increased, and it is easy to remove the water vapor layer on the surface of the metal powder. It has a large contact area and can be cooled by contacting even the molten metal droplets falling away from the central axis of the chamber.

When the first coolant spray nozzle 21 includes a plurality of coolant spray nozzles 20 , the first coolant spray nozzle 21 may have the same spray angle, and the spray angle varies according to the height of the spray nozzle. It can be adjusted to have a square shape.

In the embodiment shown in FIG. 2 , the spray angle increases as the height of the coolant spray nozzle 20 decreases. Assuming that the injection angle of the first coolant injection nozzle ₂₁ is θ 21 and the injection angle of the nth coolant injection nozzle is θ _2n , θ ₂₁ ≤ θ ₂₂ ≤ … ≤ θ _2n or θ ₂₁ < θ ₂₂ < … A relationship of < θ _2n can be established.

In the configuration in which the injection angle of the cooling water injection nozzle 20 increases as the height decreases, the cooling of the metal droplets increases toward the lower end of the chamber 1, so that the intensive injection cooling efficiency of the cooling water for one metal droplet decreases, so the contact area can have a beneficial effect in improving the overall cooling effect by maximizing the contact with a large number of metal droplets.

3 is a plan view showing an apparatus for manufacturing a metal powder according to an embodiment of the present invention. The first coolant spray nozzles 21 to the fourth coolant spray nozzles 24 are provided with four coolant spray nozzles at each height, and are arranged to be separated by 90 degrees from each other. The second coolant spray nozzle 22 is rotated 45 degrees from the first coolant spray nozzle 21 and is staggered. The third coolant spray nozzle 23 has the same arrangement as the first coolant spray nozzle 21 at the third height, and the fourth coolant spray nozzle 24 has the same arrangement as the second coolant spray nozzle 22 at the fourth height. have a layout The cooling water stage formed by this intersecting nozzle arrangement has a large contact area and allows an efficient cooling water stage to be formed.

The jetting shape of the cooling water jetting nozzle includes a nozzle jetting in a flat fan shape, and may include a cone jetting nozzle. Some of the plurality of coolant spray nozzles are sprayed in a flat fan shape and some are sprayed in a cone shape, and various coolant spraying methods may be used.

As the cooling water sprayed from the cooling water spray nozzle 20 is sprayed at high pressure and high speed, it further splits the molten metal droplets or breaks the water vapor layer on the surface of the molten metal droplet formed by the contact of the cooling water with the molten metal droplet, thereby improving the heat exchange efficiency and cooling It is possible to improve the speed and increase the amorphous degree of the metal powder produced. The pressure of the cooling water may be 80 bar to 150 bar, preferably 90 bar to 130 bar, and the injection rate of the cooling water is not limited, and the injection rate that can be obtained by the configuration of the nozzle in the pressure range of the cooling water It may be composed of

An angle adjusting means capable of adjusting the angle of the cooling water spray nozzle may be further included in the metal powder manufacturing apparatus. The angle adjusting means connects the cooling water jet nozzle to the inner wall of the chamber, and enables the cooling water jet nozzle to control the jet direction.

Since the angle of the cooling water spray nozzle can be adjusted, in the molten metal of the same composition, the particle shape of the metal powder can be adjusted to be closer to a spherical shape by adjusting the scattering distance longer. By increasing the speed, it is possible to adjust the amorphous ratio of the produced metal powder to increase.

Since the spraying angle can be adjusted according to the composition of the molten metal and the specific properties of the metal powder to be manufactured, it is possible to manufacture metal powders having various characteristics in the same apparatus.

In addition, when the composition of the molten metal is changed, the amorphous ratio due to cooling of the particles and the degree of sphericity due to the surface tension may vary even at the same coolant spray nozzle angle. can be produced at high speed.

Even when the composition of the molten metal does not change and the target properties change, if the angle of the cooling water spray nozzle is adjusted, the spherical performance is improved or the particle size of the powder becomes uniform, without the need for new equipment or investment.

When the cooling water jet nozzle 20 is cooled by scattering molten metal droplets into the nozzle, and blocking or narrowing the nozzle's jetting port interferes with the jetting of the cooling water jet nozzle 20, or the cooling water flows down along the inner surface of the chamber, the cooling water In order to prevent the case of interfering with the injection of the injection nozzle, the chamber 1 includes a shielding plate 30 covering the cooling water injection nozzle 20 on the inner wall to protect the cooling water injection nozzle 20 .

The shielding plate is installed on the upper part of the coolant spray nozzle 20 and covers or surrounds the coolant spray nozzle 20 from metal droplets scattered without blocking the spray path of the coolant spray nozzle 20. It is not limited to its structure. The shielding plate 30 may be in the form of a flat plate, or in the form of a folded flat plate, which is made of a curved surface or surrounds a part of a spherical surface or both the upper and lower portions of the coolant injection nozzle, and only the portion corresponding to the injection path is opened. may be in the form

Features, structures, effects, etc. exemplified in each of the above-described embodiments may be combined or modified for other embodiments by those of ordinary skill in the art to which the embodiments belong. Accordingly, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

1: Chamber 10: Molten metal supply container
11: injection pipe 12: fluid injection nozzle
13: protruding end 14: guide structure
15: nozzle body 16: fluid supply pipe
17: fluid injection port 18: injection pipe support
20: cooling water injection nozzle 21: first cooling water injection nozzle
22: second coolant injection nozzle 23: third coolant injection nozzle
24: fourth cooling water injection nozzle 30: shielding plate

Claims (11)

a hollow tube having a main body and a hollow tube formed inside the main body, the injection tube for spraying the molten metal liquid flowing through the hollow tube to the outside; and
As a fluid injection nozzle to which the injection pipe is mounted, the fluid injection unit comprising a nozzle body and a through hole through which the injection tube can be mounted, and a fluid injection unit for injecting a fluid into the molten metal liquid injection stem injected from the injection tube. including a nozzle;
The spray pipe has a protruding end protruding outside the through hole through the through hole spray assembly.
According to claim 1,
The fluid spraying unit includes a fluid supply pipe provided in the nozzle body, and a fluid injection port for spraying the fluid supplied from the fluid supply pipe to the outside.
3. The method of claim 2,
The fluid nozzle is a spray assembly for spraying the fluid in the shortest path to the splitting point where the spraying stem of the molten metal liquid is split.
4. The method of claim 3,
The protruding end portion has an inclined surface to provide the shortest path to the fluid sprayed from the fluid injection port.
5. The method of claim 4,
A spray assembly with a distance between the splitting point and the protruding end of 2 mm to 10 mm.
5. The method of claim 4,
A spray assembly with a distance between the splitting point and the fluid nozzle of 5 mm to 45 mm.
5. The method of claim 4,
The fluid nozzle is a spray assembly for spraying the fluid at an angle of 10 ° to 80 ° to the molten metal liquid spray stem.
According to claim 1,
A spray assembly comprising a spray pipe support provided on the upper portion of the through-hole and mounted on the outside of the main body of the spray pipe when the spray tube passes through the through hole to adjust the length of the protruding end.
3. The method of claim 2,
The fluid nozzle is an annular nozzle surrounding the injection pipe.
4. The method of claim 3,
The protruding end portion has a guide structure to provide the shortest path to the fluid sprayed from the fluid injection port.
It comprises the spray assembly of claims 1 to 10,
a chamber for cooling the fragmented molten metal droplets; and
and a coolant spray nozzle provided on the inner wall of the chamber to cool the split molten metal droplet,
The cooling water jet nozzle includes a cooling water jet nozzle for jetting cooling water in a sectoral shape.

Images