Gas atomizer

Abstract

To improve the capability to pulverize a molten material by a flow of gas.SOLUTION: A gas atomizer 100 comprises a material supply unit 130 that allows a liquid in which a material is melted to flow down, a main body 212 that is arranged in a manner surrounding a flow of the liquid flowing down, a flow guide 210 that has a plurality of slits 216 formed at a lower end of the main body 212, and a jet nozzle 220 that has one or a plurality of openings 222 provided annularly along an outer periphery of the main body 212 of the flow guide 210 and for jetting gas obliquely downward from the openings 222.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a gas atomizing device. [Background technology]

[0002] Metal powders are used in various fields such as electronic materials, catalysts, and 3D printers. In order to improve the performance of metal powders, there is a demand for finer metal powders. Gas atomization equipment has been developed as a technology for producing metal powders with sizes between 1 μm and 500 μm at low cost.

[0003] The gas atomizing device includes, for example, a material supplying unit that causes the molten metal to flow down, and an injection nozzle that injects gas toward the flow of the molten metal. In the gas atomizing device, gas is injected from the injection nozzle provided around the periphery of the flow of the molten metal, and the gas is made to collide with the molten metal, thereby pulverizing the molten metal. The pulverized molten metal is air-cooled as it falls, thereby producing metal powder.

[0004] In the gas atomizing device, the particle size of the produced metal powder can be reduced by increasing the flow rate of the gas injected from the injection nozzle. However, when the gas flow rate is increased, the upward flow of the gas generated at the collision point between the molten metal and the gas flow becomes large. This causes a problem that the molten metal adheres to the injection nozzle due to the flow of the gas, and the adhered molten metal solidifies and clogs the injection nozzle.

[0005] Therefore, a technology has been developed in which a cylindrical flow guide is provided between the molten metal flow and the injection nozzle, and the injected gas flow is deflected by colliding with the outer wall of the flow guide, thereby preventing the upstream side from reaching the injection nozzle (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 61-266504 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the technology equipped with a flow guide described in Patent Document 1 above has the problem that the collision of the gas flow with the flow guide reduces the gas flow velocity, thereby reducing the ability of the gas flow to crush the molten metal.

[0008] In view of the above problems, the present disclosure aims to provide a gas atomizing device capable of improving the ability to crush molten material using a gas flow. [Means for solving the problem]

[0009] In order to solve the above problems, a gas atomization device according to one embodiment of the present disclosure includes a material supply section that causes a liquid of molten material to flow downward, a flow guide having a main body arranged to surround the flow of the flowing liquid and a plurality of slits formed at the lower end of the main body, and an injection nozzle having one or more openings arranged in a ring shape along the outer periphery of the main body of the flow guide and that injects gas diagonally downward from the openings.

[0010] In addition, the gas injected from the opening of the injection nozzle may include a first gas flow that passes through a slit in the flow guide and collides with the liquid flow at a first height position, and a second gas flow that collides with the main body of the flow guide, is deflected, and collides with the liquid flow at a second height position lower than the first height position.

[0011] Additionally, the flow guide may have two or more and five or less slits.

[0012] The opening width of the slit of the flow guide may be gradually increased from the top to the bottom.

[0013] In addition, the main body of the flow guide may protrude downward below the opening of the injection nozzle, and the total area of ​​the multiple slits may be 2.0% or more and 6.8% or less of the area of ​​the protruding portion of the main body of the flow guide.

[0014] The body of the flow guide protrudes downward beyond the opening of the injection nozzle, and the amount of protrusion of the body of the flow guide may be more than 2.0 mm and not more than 3.0 mm. Effect of the Invention

[0015] According to the present disclosure, it is possible to improve the ability of a gas flow to break up molten material. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram illustrating a gas atomizing device according to an embodiment. [Diagram 2] FIG. 2 is a vertical sectional view of the injection mechanism according to the embodiment. [Diagram 3] FIG. 3 is a diagram illustrating a gas flow injected by the injection nozzle according to the embodiment. [Figure 4] FIG. 4 is a diagram for explaining the positional relationship between the main body and slits of the flow guide according to the embodiment and the opening of the injection nozzle. [Diagram 5] FIG. 5 is a table showing the test conditions for the examples and comparative examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values ​​shown in the embodiments are merely examples for ease of understanding, and do not limit the present disclosure unless otherwise specified. In this specification and the drawings, elements having substantially the same functions and configurations are given the same reference numerals to avoid repeated explanation. In addition, elements not directly related to the present disclosure are not illustrated.

[0018] [Gas atomizing device 100] 1 is a diagram illustrating a gas atomizing apparatus 100 according to this embodiment. The gas atomizing apparatus 100 according to this embodiment is, for example, a free-fall type gas atomizing apparatus. In the free-fall type gas atomizing apparatus 100, an ingot 10 (metal material) is directly heated and melted, and the molten metal obtained is allowed to flow down (fall), and gas is injected into the flow of the molten metal to powderize the molten metal.

[0019] As shown in FIG. 1, the gas atomizing apparatus 100 according to this embodiment includes, for example, a melting chamber 110, a cooling chamber 120, a material supply unit 130, an injection mechanism 140, an injection gas supply unit 150, an exhaust mechanism 160, and a recovery mechanism 180.

[0020] The melting chamber 110 is a chamber in which the ingot 10 is melted (dissolved). The cooling chamber 120 is provided below the melting chamber 110. The cooling chamber 120 is water-cooled by a water-cooling jacket (not shown). The melting chamber 110 and the cooling chamber 120 are communicated with each other by an opening 112. The water-cooling mechanism 114 water-cools the periphery of the opening 112 in the melting chamber 110.

[0021] A material supply unit 130 is provided within the melting chamber 110. The material supply unit 130 melts the ingot 10 and causes the molten metal produced thereby to flow down. The ingot 10 is a metal that has been refined and turned into a lump. The ingot 10 is also called a bullion or a cast metal. The type of metal that constitutes the ingot 10 is not limited. The molten metal is a solid metal that has been melted by heating and turned into a liquid.

[0022] In this embodiment, the material supply unit 130 includes, for example, a rotating rod 132, a motor 134, a heating unit 136, and a funnel 138.

[0023] The rotating rod 132 is a circular rod extending in the vertical direction. The rotating rod 132 penetrates the upper surface of the melting chamber 110. The ingot 10 is held at the lower end of the rotating rod 132. A motor 134 is connected to the upper end of the rotating rod 132. The motor 134 rotates the ingot 10 via the rotating rod 132. The rotating rod 132 is also moved up and down by an actuator (not shown).

[0024] The heating unit 136 heats and melts the ingot 10. The heating unit 136 heats the ingot 10 by, for example, induction heating. The heating unit 136 has, for example, an induction coil and a power source that applies a high-frequency current to the induction coil.

[0025] The funnel 138 is made of quartz. The funnel 138 is provided between the ingot 10 and the heating section 136. The funnel 138 blocks the upstream flow (upward flow) generated in the cooling chamber 120, which will be described later, from contacting the molten metal.

[0026] The cooling chamber 120 is provided with an injection mechanism 140. The injection mechanism 140 injects gas into the flow of molten metal flowing down (falling) from the melting chamber 110 through the opening 112 to pulverize the molten metal. The molten metal pulverized by the injection mechanism 140 is air-cooled and solidified as it falls through the cooling chamber 120. The metal powder thus produced is collected by a collection mechanism 180, which will be described later. The specific configuration of the injection mechanism 140 will be described in detail later.

[0027] The ejection gas supply unit 150 supplies gas to the ejection mechanism 140. The gas is, for example, an inert gas such as argon (Ar) or nitrogen (N2). The ejection gas supply unit 150 includes, for example, a supply pipe 152 and an on-off valve 152a. The supply pipe 152 connects a gas supply source and the ejection nozzle 220 (see FIG. 2) of the ejection mechanism 140. The on-off valve 152a is provided in the supply pipe 152. The on-off valve 152a opens and closes the supply pipe 152.

[0028] The exhaust mechanism 160 exhausts gas from the melting chamber 110 and the cooling chamber 120. The exhaust mechanism 160 includes, for example, a rotary pump 162, a mechanical booster pump 164, exhaust pipes 166, 168, and 170, and on-off valves 166a, 166b, 168a, and 170a.

[0029] The discharge side of the rotary pump 162 is open to the atmosphere. The suction side of the rotary pump 162 is connected to the discharge side of a mechanical booster pump 164. The suction side of the mechanical booster pump 164 is connected to an exhaust pipe 166.

[0030] An exhaust pipe 166 connects the mechanical booster pump 164 and the melting chamber 110. On-off valves 166a and 166b are provided in the exhaust pipe 166. The on-off valves 166a and 166b open and close the exhaust pipe 166. An exhaust pipe 168 connects a portion of the exhaust pipe 166 between the on-off valves 166a and 166b and the cooling chamber 120. An on-off valve 168a is provided in the exhaust pipe 168. The on-off valve 168a opens and closes the exhaust pipe 168. An exhaust pipe 170 connects a downstream side of the on-off valve 168a in the exhaust pipe 168 and the melting chamber 110. An on-off valve 170a is provided in the exhaust pipe 170. The on-off valve 170a opens and closes the exhaust pipe 170.

[0031] The recovery mechanism 180 includes, for example, a first recovery pot 182, a connecting pipe 184, a cyclone 186, a second recovery pot 188, a connecting pipe 190, a check valve 190a, and a dust collector 192.

[0032] The first recovery pot 182 is connected to the lower end of the cooling chamber 120. The metal powder that falls from the cooling chamber 120 is stored in the first recovery pot 182.

[0033] A connecting pipe 184 connects the first recovery pot 182 and a cyclone 186 .

[0034] The cyclone 186 separates the gas-solid mixture of gas and metal powder provided from the cooling chamber 120 into gas and metal powder.

[0035] Second collection pot 188 is connected to the lower end of cyclone 186. Second collection pot 188 stores the metal powder separated by cyclone 186. The average particle size of the metal powder stored in second collection pot 188 is smaller than the average particle size of the metal powder stored in first collection pot 182.

[0036] A connecting pipe 190 connects the upper end of the cyclone 186 to a dust collector 192. A check valve 190a is provided on the connecting pipe 190. The check valve 190a prevents gas from flowing back from the dust collector 192 to the cyclone 186.

[0037] The dust collector 192 collects the metal powder from the solid-gas mixture of the gas and the metal powder supplied from the cyclone 186. The dust collector 192 is connected to a suction pump (not shown).

[0038] [Operation of the gas atomization device 100] Next, the operation of the gas atomizing device 100 will be described. First, the ingot 10 is attached to the rotating rod 132 and moved to the vicinity of the induction coil of the heating unit 136. When the melting atmosphere is an inert gas atmosphere, the inert gas is supplied by the injection gas supply unit 150, and the inside of the melting chamber 110 is evacuated by the exhaust mechanism 160, thereby replacing the inside of the melting chamber 110 with an inert gas atmosphere. After the replacement inside the melting chamber 110 is completed, the operation of the injection gas supply unit 150 and the exhaust mechanism 160 is stopped.

[0039] Then, the operation of the heating unit 136 is started to heat the surface of the ingot 10 and melt the ingot 10. As a result, molten metal is generated, and the flow of the molten metal flows down into the cooling chamber 120 through the opening 112. Note that in this embodiment, the central axis of the flow of the molten metal coincides with the central axis of the opening 112.

[0040] Furthermore, the injection gas supply unit 150 is operated to inject gas from the injection mechanism 140. The gas then collides with the flow of molten metal flowing down from the melting chamber 110, pulverizing the molten metal. The molten metal pulverized by the injection mechanism 140 is air-cooled and solidified as it falls through the cooling chamber 120. The metal powder thus produced is collected by the collection mechanism 180.

[0041] In order to prevent the gap between the ingot 10 and the heating part 136 from becoming larger due to melting, the rotating rod 132 may be lowered by the amount of melting to maintain a constant gap between the ingot 10 and the heating part 136. This allows a continuous flow of molten metal to be generated, and metal powder to be produced continuously.

[0042] When a predetermined amount of metal powder has been produced, the operation of the heating unit 136 and the operation of the injection gas supply unit 150 are stopped. Then, the metal powder recovered by the recovery mechanism 180 is taken out of the gas atomizing apparatus 100.

[0043] [Injection mechanism 140] Next, a specific configuration of the injection mechanism 140 according to this embodiment will be described. Fig. 2 is a vertical cross-sectional view of the injection mechanism 140 according to this embodiment.

[0044] As shown in FIG. 2, the injection mechanism 140 includes a flow guide 210 and an injection nozzle 220 .

[0045] The flow guide 210 has, for example, a main body 212, a flange portion 214, and a plurality of slits 216. The main body 212 is, for example, tubular. The main body 212 is, for example, cylindrical, elliptical, or rectangular. The inner diameter of the main body 212 is, for example, 21 mm. The flange portion 214 is an annular disk member extending horizontally from the upper end of the main body 212. The flange portion 214 is placed on the upper surface of the nozzle upper member 224 of the injection nozzle 220 so that the central axis P of the main body 212 coincides with the central axis of the opening 112.

[0046] As described above, the central axis of the flow of molten metal coincides with the central axis of the opening 112. Therefore, the main body 212 is disposed so as to surround the flow of molten metal that has flowed down. In other words, the flow of molten metal flows down inside the main body 212.

[0047] Furthermore, the main body 212 protrudes downward beyond an opening 222 of an injection nozzle 220, which will be described later.

[0048] The multiple slits 216 are formed in the lower end of the main body 212. The multiple slits 216 are provided, for example, at equal intervals in the circumferential direction of the main body 212.

[0049] The injection nozzle 220 has one opening 222 formed in an annular shape along the outer periphery of the body 212 of the flow guide 210. That is, in this embodiment, the opening 222 of the injection nozzle 220 is annular. Furthermore, the injection nozzle 220 injects gas obliquely downward from the opening 222. The opening 222 of the injection nozzle 220 is designed, for example, such that the injected gas is concentrated at a point P1 on the central axis P. The injection nozzle 220 injects gas obliquely downward from the opening 222 toward the flow of the molten metal.

[0050] The injection nozzle 220 is, for example, a supersonic nozzle (Laval nozzle). For example, as shown in Fig. 2, the injection nozzle 220 includes a nozzle upper member 224 and a nozzle lower member 226. The nozzle upper member 224 and the nozzle lower member 226 are annular. The nozzle lower member 226 is provided below the nozzle upper member 224. An opening 222 is formed by a bottom surface of the nozzle upper member 224 and an inner peripheral surface of the nozzle lower member 226.

[0051] The diameter of the inner periphery of the nozzle upper member 224 is slightly larger than the outer diameter of the body 212 of the flow guide 210. The inner periphery of the nozzle upper member 224 contacts the outer periphery of the body 212 of the flow guide 210.

[0052] FIG. 3 is a diagram for explaining the gas flow injected by the injection nozzle 220 according to the present embodiment. As shown in FIG. 3, the gas injected obliquely downward from the opening 222 of the injection nozzle 220 is branched into a first gas flow F and a second gas flow S. The first gas flow F shown by a solid line in FIG. 3 is a gas flow that passes through the slit 216 of the flow guide 210 and collides with the flow D of the molten metal. In other words, a part of the gas injected from the opening 222 of the injection nozzle 220 is bled into the inside of the main body 212 by the slit 216 and becomes the first gas flow F. The second gas flow S shown by fine cross-hatching in FIG. 3 collides with the outer peripheral surface of the main body 212 of the flow guide 210, is deflected, and collides with the flow D of the molten metal.

[0053] The first gas flow F that passes through the multiple slits 216 is concentrated at a point P1 on the central axis P. That is, the first gas flow F collides with the molten metal flow D at a height position H1 of the point P1. Therefore, the molten metal flow D is first coarsely crushed (primary crushed) by the first gas flow F at the first height position H1. The height position H1 is a vertical position that includes the point P1.

[0054] Moreover, the second gas flow S deflected by the main body 212 of the flow guide 210 gradually spreads in the horizontal direction as it goes downward, and the end portion on the central axis P side is gathered at a point P2 on the central axis P. The point P2 is located lower than the point P1. Therefore, the second gas flow S starts to collide with the molten metal flow D at a height position H2 (second height position) lower than the height position H1. Then, at a height position H3 (second height position) of the point P2, the second gas flow S collides with the molten metal flow D over the entire horizontal direction. Therefore, at the height position H1, the molten metal flow D coarsely crushed by the first gas flow F is further crushed (secondary crushed) by the second gas flow S.

[0055] In this manner, the molten metal flow D collides with the first gas flow F, and then with the second gas flow S. That is, the molten metal flow D collides with the gas flow in two stages.

[0056] As described above, the first gas flow F passes through the slit 216 without colliding with the main body 212 of the flow guide 210, and collides with the molten metal flow D. Therefore, the first gas flow F collides with the molten metal flow D while maintaining the flow velocity of the gas injected from the opening 222. This allows the molten metal to be efficiently pulverized by the gas flow at the height position H1.

[0057] Then, the flow D of the molten metal pulverized at the height position H1 collides with the second gas flow S below the height position H1. The second gas flow S is deflected by colliding with the outer peripheral surface of the main body 212 of the flow guide 210, and therefore has a lower flow rate than the first gas flow F. However, the second gas flow S collides with the flow D of the molten metal pulverized by the first gas flow F. Therefore, the gas atomizing device 100 according to this embodiment can improve the pulverizing ability of the molten metal by the gas flow compared to the conventional technology in which the flow D of the molten metal is pulverized only by the second gas flow S. Therefore, the gas atomizing device 100 according to this embodiment can produce a metal powder having a smaller average particle size compared to the conventional technology equipped with a flow guide without the slit 216.

[0058] Moreover, the gas atomizing apparatus 100 according to this embodiment includes a flow guide 210 having a main body 212. This makes it possible to prevent the upward blowing upstream generated at the collision point (at height position H1 and below height position H1) between the molten metal flow D and the gas flow from reaching the opening 222 of the injection nozzle 220. Therefore, the gas atomizing apparatus 100 according to this embodiment makes it possible to prevent adhesion of the molten metal at the opening 222 of the injection nozzle 220.

[0059] In addition, the flow guide 210 preferably has two or more and five or less slits 216, and more preferably has four slits 216. If the flow guide 210 has only one or less slits 216, the ratio of primary crushing by the first gas flow F is too low, and the degree of improvement in the crushing ability of the molten metal is low. On the other hand, if the flow guide 210 has six or more slits 216, the first gas flow F increases, and the upward blowing stream generated at the height position H1 increases. For this reason, by having the flow guide 210 have two or more and five or less slits 216, it is possible to improve the crushing ability of the molten metal and prevent the adhesion of the molten metal to the opening 222 of the injection nozzle 220 by reducing the blowing stream. In addition, by having the flow guide 210 have four slits 216, it is possible to further improve the crushing ability of the molten metal and prevent the adhesion of the molten metal to the opening 222 of the injection nozzle 220 by further reducing the blowing stream.

[0060] FIG. 4 is a diagram for explaining the positional relationship between the main body 212 and the slits 216 of the flow guide 210 according to this embodiment and the opening 222 of the injection nozzle 220. As shown in FIG.

[0061] As shown in Fig. 4, it is preferable that the opening width of the slit 216 of the flow guide 210 gradually increases from the top to the bottom. This allows the first gas flow F to be gradually increased from the top to the bottom. Therefore, the gas atomizing device 100 can further improve the pulverizing ability of the molten metal. The shape of the slit 216 may be a triangle, a semi-ellipse, or a semi-circle as shown in Figs. 2 and 3.

[0062] The upper end of the slit 216 may be at the same height as the opening 222 of the injection nozzle 220 .

[0063] As described above, the body 212 of the flow guide 210 protrudes downward from the opening 222 of the injection nozzle 220. The protrusion amount T of the body 212 of the flow guide 210 is preferably more than 2.0 mm and not more than 3.0 mm, and more preferably 2.5 mm. If the protrusion amount T of the body 212 of the flow guide 210 is not more than 2.0 mm, an upward blowing stream that reaches the opening 222 of the injection nozzle 220 is generated. On the other hand, if the protrusion amount T of the body 212 of the flow guide 210 is more than 3.0 mm, the improvement of the crushing ability of the molten metal is reduced. Therefore, by setting the protrusion amount T of the body 212 of the flow guide 210 to more than 2.0 mm and not more than 3.0 mm, it is possible to prevent the molten metal from adhering to the opening 222 of the injection nozzle 220 due to a reduction in the blowing stream, and to improve the crushing ability of the molten metal. In addition, since the protrusion amount T of the main body 212 of the flow guide 210 is 2.5 mm, it is possible to prevent the molten metal from adhering to the opening 222 of the injection nozzle 220 by further reducing the blow-up stream, and to further improve the crushing ability of the molten metal.

[0064] In addition, the total area of ​​the plurality of slits 216 is preferably 2.0% or more and 6.8% or less of the area of ​​the protruding portion of the body 212 of the flow guide 210. If the total area of ​​the plurality of slits 216 is less than 2.0% of the area of ​​the protruding portion of the body 212 of the flow guide 210, the ratio of primary crushing by the first gas flow F is too low, and the degree of improvement in the crushing ability of the molten metal is low. On the other hand, if the total area of ​​the plurality of slits 216 is more than 6.8% of the area of ​​the protruding portion of the body 212 of the flow guide 210, the first gas flow F becomes large, and the upward blowing stream generated at the height position H1 increases. For this reason, by making the total area of ​​the plurality of slits 216 2.0% or more and 6.8% or less of the area of ​​the protruding portion of the body 212 of the flow guide 210, it is possible to simultaneously improve the crushing ability of the molten metal and prevent the adhesion of the molten metal to the opening 222 of the injection nozzle 220 due to the reduction in the blowing stream.

[0065] As described above, the gas atomizing device 100 according to this embodiment can improve the pulverizing capacity of the molten metal.

[0066] [Example] Tests were carried out using the injection mechanisms 140 of Examples 1 to 4 and the injection mechanisms 140 of Comparative Examples 1 to 7.

[0067] FIG. 5 is a table showing the test conditions of the examples and the comparative example. As shown in FIG. 5, in the examples 1 to 4, the number of slits 216 was four. In the example 1, the protrusion amount T was 2.5 [mm], and the pressure of the gas injected from the injection nozzle 220 was 4.0 [MPa]. In the example 2, the protrusion amount T was 2.5 [mm], and the pressure of the gas injected from the injection nozzle 220 was 5.0 [MPa]. In the example 3, the protrusion amount T was 3.0 [mm], and the pressure of the gas injected from the injection nozzle 220 was 4.0 [MPa]. In the example 4, the protrusion amount T was 3.0 [mm], and the pressure of the gas injected from the injection nozzle 220 was 5.0 [MPa].

[0068] In Comparative Examples 1 to 4, the flow guide 210 does not have the slit 216. In Comparative Example 1, the protrusion amount T is 2.5 [mm], and the pressure of the gas injected from the injection nozzle 220 is 4.0 [MPa]. In Comparative Example 2, the protrusion amount T is 2.5 [mm], and the pressure of the gas injected from the injection nozzle 220 is 5.0 [MPa]. In Comparative Example 3, the protrusion amount T is 3.0 [mm], and the pressure of the gas injected from the injection nozzle 220 is 4.0 [MPa]. In Comparative Example 4, the protrusion amount T is 3.0 [mm], and the pressure of the gas injected from the injection nozzle 220 is 5.0 [MPa].

[0069] In Examples 1 to 4 and Comparative Examples 1 to 4, clogging of the opening 222 of the injection nozzle 220 due to adhesion of the molten metal was not observed. On the other hand, it was confirmed that Examples 1 to 4 produced a larger amount (weight ratio) of metal powder having a particle size of 106 μm or less than Comparative Examples 1 to 4. It was confirmed that Example 1 produced a 22% larger amount of metal powder having a particle size of 106 μm or less than Comparative Example 1. It was confirmed that Example 2 produced a 22% larger amount of metal powder having a particle size of 106 μm or less than Comparative Example 2. It was confirmed that Example 3 produced a 23% larger amount of metal powder having a particle size of 106 μm or less than Comparative Example 3. It was confirmed that Example 4 produced a 23% larger amount of metal powder having a particle size of 106 μm or less than Comparative Example 4.

[0070] In Comparative Examples 5 and 6, clogging of the opening 222 of the injection nozzle 220 due to adhesion of the molten metal was observed.

[0071] From the above results, it was confirmed that the flow guide 210 preferably has two or more and five or less slits 216.

[0072] In Comparative Example 7, clogging of the opening 222 of the injection nozzle 220 due to adhesion of the molten metal was observed.

[0073] From the above results, it was confirmed that the protrusion amount T of the main body 212 of the flow guide 210 is preferably more than 2.0 mm and 3.0 mm or less.

[0074] Although the embodiments have been described above with reference to the accompanying drawings, it goes without saying that the present disclosure is not limited to the above-described embodiments. It is clear that a person skilled in the art can think of various modified or altered examples within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure.

[0075] For example, in the above embodiment, the gas atomizing apparatus 100 produces metal powder. However, the gas atomizing apparatus 100 may produce resin or glass powder. In this case, the material supply unit 130 may melt the resin or glass as a material and allow the molten liquid to flow down.

[0076] In the above embodiment, the injection nozzle 220 has one annular opening 222. However, the injection nozzle 220 may have a plurality of openings 222. In this case, the plurality of openings 222 may be provided annularly along the outer periphery of the main body 212 of the flow guide 210. [Explanation of symbols]

[0077] 100 Gas atomizer 130 Material supply department 210 Flow Guide 212 Main unit 216 Slit 220 Injection Nozzle 222 Aperture

Claims

1. a material supplying section for causing a liquid obtained by melting a material to flow down; A flow guide including a main body arranged to surround the flow of the liquid that has flowed down and a plurality of slits formed in a lower end of the main body; an injection nozzle having one or more openings provided annularly along an outer periphery of the body of the flow guide, the injection nozzle injecting gas obliquely downward from the openings; A gas atomizing device comprising:

2. The gas injected from the opening of the injection nozzle is a first gas flow passing through the slit of the flow guide and impinging on the liquid flow at a first elevation; a second gas flow that is deflected by impacting the body of the flow guide and impacts the liquid flow at a second elevation that is lower than the first elevation; and The gas atomizing apparatus of claim 1 , comprising:

3. The gas atomizing apparatus according to claim 1 or 2, wherein the flow guide has two or more and five or less of the slits.

4. 3. The gas atomizing device according to claim 1, wherein an opening width of the slit of the flow guide gradually increases from the top to the bottom.

5. The body of the flow guide protrudes downward beyond the opening of the injection nozzle, 3. The gas atomizing device according to claim 1, wherein a total area of ​​the plurality of slits is 2.0% or more and 6.8% or less of an area of ​​the protruding portion of the main body of the flow guide.

6. The body of the flow guide protrudes downward beyond the opening of the injection nozzle, The gas atomizing device according to claim 1 or 2, wherein a protrusion amount of the body of the flow guide is more than 2.0 mm and is not more than 3.0 mm.

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