Atomizer for improving the uniformity of the particle size of metal powder

Abstract

The application discloses an atomizer for improving granularity uniformity of metal powder, comprising: a smelting furnace for melting metal materials into liquid metal; an atomizing furnace for atomizing and cooling the liquid metal to form metal powder; a flow guide structure for spraying the liquid metal from a smelting chamber into an atomizing chamber; a first atomizing mechanism and a second atomizing mechanism in an upstream and downstream relationship along a spraying direction of the liquid metal, the first atomizing mechanism being used for forming turbulent flow of atomizing medium and contacting with the liquid metal, and the second atomizing mechanism being used for forming vortex flow of atomizing medium and contacting with the liquid metal. The application has the beneficial effect that the structure is ingeniously and reasonably designed, so that the granularity uniformity of the metal powder is higher.

Description

Technical Field

[0001] This invention relates to an atomizer for improving the particle size uniformity of metal powder, belonging to the field of metal powder preparation technology. Background Technology

[0002] Currently, in the field of metal powder preparation technology, a commonly used method is to use an atomizing medium to disperse, atomize, and then cool and solidify a jet of molten metal into metal powder. Metal powders obtained using this method have good sphericity and superior physical properties.

[0003] For example, the invention patent with prior art publication number CN107262730B discloses a gas atomization preparation method and equipment for micro-spherical metal powder. In this invention patent, the lower end of the guide nozzle is surrounded by an annular slit or annular hole atomizer. The metal liquid is sprayed out from the lower end of the guide nozzle to form a metal liquid jet. The atomizer sprays a high-speed airflow to atomize and cool the metal liquid jet to form metal powder.

[0004] The invention patent has the following defects: the contact efficiency between the metal liquid jet and the atomizing medium (high-speed airflow) is low, which makes it impossible for the atomizing medium to fully impact and disperse the metal liquid jet. The particle size uniformity of the metal droplets formed by atomization is low, resulting in low particle size uniformity of the final metal powder. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an atomizer that improves the particle size uniformity of metal powder. The atomizer has a clever and reasonable structural design, which makes the metal powder have higher particle size uniformity.

[0006] The present invention is achieved through the following technical solution.

[0007] An atomizer for improving the particle size uniformity of metal powder, comprising: A smelting furnace is used to melt metallic materials into liquid metal. Atomizing furnace is used to atomize and cool liquid metal to form metal powder. A flow guiding structure is used to inject liquid metal from the melting chamber into the atomization chamber; The first atomizing mechanism and the second atomizing mechanism are in an upstream-downstream relationship along the direction of liquid metal injection. The first atomizing mechanism is used to form a turbulent flow of atomized medium and bring it into contact with the liquid metal, while the second atomizing mechanism is used to form a vortex flow of atomized medium and bring it into contact with the liquid metal.

[0008] As a further improvement of the present invention, the flow guiding structure has a plurality of flow guiding holes arranged in a ring and connecting the melting furnace and the atomizing furnace, or has a flow guiding groove arranged in a ring and connecting the melting furnace and the atomizing furnace, so that liquid metal is injected from the melting chamber into the atomizing chamber and forms a liquid metal jet band.

[0009] As a further improvement of the present invention, the first atomizing mechanism includes a plurality of first spray units surrounding the inner periphery of the metal liquid jet band and a plurality of second spray units surrounding the outer periphery of the metal liquid jet band; the second atomizing mechanism includes a plurality of third spray units surrounding the inner periphery of the metal liquid jet band and a plurality of fourth spray units surrounding the outer periphery of the metal liquid jet band.

[0010] As a further improvement of the present invention, the injection direction of the first injection unit is adapted to form a first atomizing medium vortex with the ejected atomized medium, the injection direction of the second injection unit is adapted to form a second atomizing medium vortex with the ejected atomized medium, and the rotation directions of the first atomizing medium vortex and the second atomizing medium vortex are opposite; the injection direction of the third injection unit is adapted to form a third atomizing medium vortex with the ejected atomized medium, and the injection direction of the fourth injection unit is adapted to form a fourth atomizing medium vortex with the ejected atomized medium, and the rotation directions of the third atomizing medium vortex and the fourth atomizing medium vortex are the same.

[0011] As a further improvement of the present invention, the spraying directions of the first spraying unit, the second spraying unit, the third spraying unit, and the fourth spraying unit are all orthogonally decomposed into a first spraying direction along the liquid metal spraying direction and a second spraying direction that forms a vortex.

[0012] As a further improvement of the present invention, the atomizing furnace is provided with an inner cylinder, a middle cylinder, and an outer cylinder; the space between the inner cylinder and the middle cylinder forms an atomizing space for atomizing the liquid metal jet; the space inside the inner cylinder and the space between the middle cylinder and the outer cylinder are used to transport the atomizing medium; the first spray unit and the third spray unit are disposed on the outer wall of the inner cylinder, and the second spray unit and the fourth spray unit are disposed on the inner wall of the middle cylinder.

[0013] As a further improvement of the present invention, the inner cylinder is connected to a first delivery pipe for providing atomizing medium, and a plurality of through holes are formed on the inner cylinder, the through holes forming the first injection unit and the third injection unit; the outer cylinder is connected to a second delivery pipe for providing atomizing medium, and a plurality of through holes are formed on the middle cylinder, the through holes forming the second injection unit and the fourth injection unit.

[0014] As a further improvement of the present invention, a partition is provided between the middle cylinder and the outer cylinder to divide the space into a first space and a second space; the second injection unit corresponds to the first space and the fourth injection unit corresponds to the second space; a heating structure for heating the atomizing medium is provided in the first space and a cooling structure for cooling the atomizing medium is provided in the second space; the second conveying pipe forms a branch pipe, which connects the first space and the second space respectively.

[0015] As a further improvement of the present invention, the heating structure is configured as an electric heating wire coiled and arranged in the first space.

[0016] As a further improvement of the present invention, the cooling structure is configured as a refrigerant pipe coiled and arranged in the second space.

[0017] The beneficial effects of this invention are: During its flow, the liquid metal first encounters turbulence generated by the atomizing medium from the first atomizing mechanism, and then eddies generated by the atomizing medium from the second atomizing mechanism. Under the action of turbulence, the liquid metal is sufficiently impacted and atomized, forming metal droplets. This improves the efficiency of contact and atomization with the atomizing medium. The turbulence can also repeatedly disperse larger metal droplets and increase the frequency of collisions between them, resulting in smaller droplets. These droplets gradually cool and form metal powder, resulting in a final metal powder with higher particle size uniformity and smaller particle size. The highly uniform and small-sized metal droplets formed by turbulence are then subjected to eddies. The eddies relatively reduce the frequency of collisions between droplets and increase the frequency of contact with the atomizing medium, accelerating the rate at which the metal droplets cool and solidify into metal powder. Attached Figure Description

[0018] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings to aid in understanding the objectives and advantages of the present invention, wherein: Figure 1 This is a cross-sectional view of the atomizer from a frontal viewing angle. Figure 2 This is a cross-sectional view of the first atomizing mechanism from a top-down perspective; Figure 3 This is a cross-sectional view of the second atomizing mechanism from a top-down perspective; Figure 4 for Figure 1 A magnified view of a portion of the image. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0020] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the construction shown in the accompanying drawings. The terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive.

[0021] Reference Figures 1-4 An atomizer for improving the uniformity of metal powder particle size includes a melting furnace 1, an atomizing furnace 2, a flow guiding structure 3, a first atomizing mechanism, and a second atomizing mechanism.

[0022] The melting furnace 1 is used to melt metal materials into liquid metal, store the liquid metal and keep it at a constant temperature to keep it in a liquid state. It can be composed of a melting crucible for melting metal materials, a heat-insulating crucible for storing liquid metal, and a high-temperature resistant pipe connecting the melting crucible and the heat-insulating crucible. The heat-insulating crucible can be equipped with a heating coil to improve the heat preservation effect.

[0023] The atomizing furnace 2 provides a space in which liquid metal is atomized into metal droplets and gradually cooled and solidified to form the final product, metal powder.

[0024] The flow guiding structure 3 connects the melting furnace 1 and the atomizing furnace 2, so that the liquid metal in the melting furnace 1 is sprayed into the atomizing furnace 2 through the flow guiding structure 3, and atomized and cooled solidified in the atomizing furnace 2.

[0025] The first atomizing mechanism and the second atomizing mechanism are located inside the atomizing furnace 2, and they are in an upstream-downstream relationship along the direction of liquid metal injection. Generally, the melting furnace 1 is located above the atomizing furnace 2, and the flow guiding structure 3 is in a vertical direction, that is, the direction of liquid metal injection is vertically downward. In other words, the first atomizing mechanism and the second atomizing mechanism are in an up-down position relationship.

[0026] The first atomizing mechanism is used to create turbulence in the atomizing medium and bring it into contact with the liquid metal; the second atomizing mechanism is used to create turbulence in the atomizing medium and bring it into contact with the liquid metal.

[0027] In this embodiment, during its flow path, the liquid metal first encounters turbulence generated by the atomizing medium from the first atomizing mechanism, and then encounters eddies generated by the atomizing medium from the second atomizing mechanism. Under the action of turbulence, the liquid metal is sufficiently impacted and dispersed into atomized droplets, thereby improving the efficiency of contact and atomization with the atomizing medium. It is worth noting that the liquid metal in turbulence not only has an excellent effect of being fully dispersed, but the turbulence can also repeatedly disperse larger-diameter metal droplets and increase the frequency of collisions between metal droplets, causing them to form smaller-diameter metal droplets. These metal droplets gradually cool to form metal powder, resulting in metal powder with higher particle size uniformity and smaller particle size. The highly uniform and small-particle-size metal droplets formed under the action of turbulence are then subjected to the action of eddies. The eddies can relatively reduce the frequency of collisions between metal droplets and increase the frequency of contact with the atomizing medium, thereby accelerating the rate at which the metal droplets cool and solidify into metal powder.

[0028] The atomizer in this embodiment can fully break down the liquid metal particles by sequentially forming turbulence and eddies during the flow of liquid metal, thereby obtaining metal powder with a relatively more uniform particle size, and the obtained metal powder can have a smaller particle size.

[0029] In this embodiment, the flow guiding structure 3 has multiple annularly distributed flow guiding holes 31 that connect the melting furnace 1 and the atomizing furnace 2, or an annular flow guiding channel that connects the melting furnace 1 and the atomizing furnace 2, so that liquid metal is injected from the melting chamber into the atomizing chamber and forms a liquid metal jet band p. If the flow guiding structure 3 is provided with flow guiding holes 31, the liquid metal jet band p is composed of multiple annularly distributed liquid jets with extremely small gaps between adjacent jets; if the flow guiding structure 3 is provided with flow guiding channels, the liquid metal jet band p can be in the form of a curtain-like, annular, continuously flowing liquid. These two configurations are essentially the same in effect.

[0030] In this embodiment, the liquid metal injected into the atomizing furnace 2 is formed into a liquid metal jet band p by the flow guiding structure 3. Compared with the liquid metal injection method in the prior art, the liquid metal jet band p injected by the flow guiding structure 3 has a larger surface area, which can achieve more thorough and sufficient contact with the atomizing medium. This makes the impact and crushing effect of the atomizing medium on the liquid metal jet band p more effective and efficient. From a fundamental perspective, this can solve the problem of low uniformity of metal powder particle size caused by insufficient atomization to a certain extent.

[0031] In this embodiment, the first atomizing mechanism includes multiple first spray units a surrounding the inner periphery of the liquid metal jet belt p and multiple second spray units b surrounding the outer periphery of the liquid metal jet belt p. The first spray units a spray the atomizing medium inward from the outer periphery of the liquid metal jet belt p, and the second spray units b spray the atomizing medium outward from the inner periphery of the liquid metal jet belt p. The second atomizing mechanism includes multiple third spray units c surrounding the inner periphery of the liquid metal jet belt p and multiple fourth spray units d surrounding the outer periphery of the liquid metal jet belt p. The third spray units c spray the atomizing medium inward from the outer periphery of the liquid metal jet belt p, and the fourth spray units d spray the atomizing medium outward from the inner periphery of the liquid metal jet belt p.

[0032] Both the first and second atomizing mechanisms have multiple spraying units set inside and outside the metal liquid jet zone p, spraying atomizing media onto both the inner and outer surfaces of the metal liquid jet zone p. This fully utilizes the large surface area of ​​the metal liquid jet zone p, allowing the metal liquid to be fully subjected to the impact and shearing action of the bidirectional atomizing media, thereby producing fine and uniform metal droplets.

[0033] In this embodiment, the injection direction of the first injection unit a is adapted to form a first atomized medium vortex, and the injection direction of the second injection unit b is adapted to form a second atomized medium vortex. The rotation directions of the first and second atomized medium vortices are opposite. The injection directions of each first injection unit a are symmetrically arranged about the central axis of the metal liquid jet band p, and the injection directions of each second injection unit b are symmetrically arranged about the central axis of the metal liquid jet band p. The injection direction of the third injection unit c is adapted to form a third atomized medium vortex, and the injection direction of the fourth injection unit d is adapted to form a fourth atomized medium vortex. The rotation directions of the third and fourth atomized medium vortices are the same, and the injection directions of each third injection unit c and each fourth injection unit d are symmetrically arranged about the central axis of the metal liquid jet band p.

[0034] In this embodiment, the injection directions r of the first injection unit a, the second injection unit b, the third injection unit c, and the fourth injection unit d are orthogonally decomposed into a first injection direction r1 along the liquid metal injection direction and a second injection direction r2 that forms vortices. The first injection direction r1 allows turbulence and vortices to act on the liquid metal jet p while also assisting in propelling the liquid metal jet p, thereby improving the overall atomization efficiency. As for the second injection direction r2, as... Figure 2 , 3As shown, the second jet direction r2 of the first jet unit a is clockwise, and the second jet direction r2 of the second jet unit b is counterclockwise. These opposite directions create turbulence. It's important to note that the overall jet intensity of the first jet unit a and the second jet unit b are approximately the same to balance the resulting turbulence. Similarly, the second jet direction r2 of the third jet unit c and the fourth jet unit d are clockwise, creating vortices. Again, it's important to note that the overall jet intensity of the third jet unit c and the fourth jet unit d are approximately the same to balance the resulting vortices.

[0035] More specifically regarding the internal structure of the atomizing furnace 2, the atomizing furnace 2 is provided with an inner cylinder 21, a middle cylinder 22, and an outer cylinder 23. The space between the inner cylinder 21 and the middle cylinder 22 forms an atomizing space s for atomizing the metal liquid jet p. The space inside the inner cylinder 21 and the space between the middle cylinder 22 and the outer cylinder 23 are used to transport the atomizing medium. The first spray unit a and the third spray unit c are provided on the outer wall of the inner cylinder 21, and the second spray unit b and the fourth spray unit d are provided on the inner wall of the middle cylinder 22.

[0036] Because the liquid metal jet p is confined within the atomization space s for atomization, the outward diffusion of metal powder is prevented. This not only facilitates collection but also avoids the collection of metal powder accumulated in other locations inside the atomization furnace 2. Furthermore, due to the turbulence and eddies formed within the atomization space s, i.e., the strong gas flow within the atomization space s, metal powder is less likely to adhere to the outer wall of the inner cylinder 21 and the inner wall of the middle cylinder 22.

[0037] For the first injection unit a, the second injection unit b, the third injection unit c, and the fourth injection unit d, setting them as nozzles or through holes to spray the atomized medium can achieve essentially the same effect.

[0038] To reduce product costs and simplify assembly, the inner cylinder 21 is connected to a first delivery pipe 41 that provides the atomizing medium. Multiple through holes are formed on the inner cylinder 21, with the upper through hole forming the first injection unit a and the lower through hole forming the third injection unit c. The outer cylinder 23 is connected to a second delivery pipe 42 that provides the atomizing medium. Multiple through holes are formed on the middle cylinder 22, with the upper through hole forming the second injection unit b and the lower through hole forming the fourth injection unit d.

[0039] It should be noted that a partition 24 is provided between the middle cylinder 22 and the outer cylinder 23, dividing the space into a first space s1 and a second space s2. The second injection unit b corresponds to the first space s1, and the fourth injection unit d corresponds to the second space s2. A heating structure 51 for heating the atomizing medium is provided in the first space s1, and a cooling structure 52 for cooling the atomizing medium is provided in the second space s2. The second delivery pipe 42 forms a branch pipe, which connects the first space s1 and the second space s2 respectively.

[0040] By setting up a heating structure 51, the atomized medium sprayed by the second spray unit b is heated, so that under the action of turbulence, the metal droplets in the liquid metal jet p do not cool and solidify into solid particles, but remain in a liquid particle state, thus resulting in higher uniformity and smaller particle size of the metal droplets. By setting up a cooling mechanism, the atomized medium sprayed by the fourth spray unit d is cooled, so that the highly uniform and smaller metal droplets gradually cool and solidify into metal powder under the action of eddies, avoiding the formation of large particles with attached satellite particles.

[0041] In this embodiment, the heating structure 51 is configured as an electric heating wire coiled and arranged in the first space s1. The motor heating wire needs to cover the entire first space s1 as much as possible to improve the heating effect.

[0042] In this embodiment, the cooling structure 52 is configured as a refrigerant pipe coiled in the second space s2, and a cooling medium flows through the refrigerant pipe. The cooling medium can be a gaseous medium or a liquid medium. The refrigerant pipe needs to cover the entire second space s2 as much as possible to improve the cooling effect.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An atomizer for improving the particle size uniformity of metal powder, characterized in that, include: A melting furnace is used to melt metallic materials into liquid metal. Atomizing furnace, used to atomize and cool liquid metal to form metal powder; A flow guiding structure is used to inject liquid metal from the melting chamber into the atomization chamber; The first atomizing mechanism and the second atomizing mechanism are in an upstream-downstream relationship along the direction of liquid metal injection. The first atomizing mechanism is used to form a turbulent flow of atomized medium and bring it into contact with the liquid metal, while the second atomizing mechanism is used to form a vortex flow of atomized medium and bring it into contact with the liquid metal. The flow guiding structure has multiple flow guiding holes arranged in a ring and connecting the melting furnace and the atomizing furnace, or it has a flow guiding groove arranged in a ring and connecting the melting furnace and the atomizing furnace, so that liquid metal is injected from the melting chamber into the atomizing chamber and forms a liquid metal jet band; The first atomizing mechanism includes multiple first spray units surrounding the inner periphery of the liquid metal jet and multiple second spray units surrounding the outer periphery of the liquid metal jet; the second atomizing mechanism includes multiple third spray units surrounding the inner periphery of the liquid metal jet and multiple fourth spray units surrounding the outer periphery of the liquid metal jet. The spraying direction of the first spraying unit is adapted to form a first atomizing medium vortex by the sprayed atomizing medium, and the spraying direction of the second spraying unit is adapted to form a second atomizing medium vortex by the sprayed atomizing medium, and the rotation directions of the first atomizing medium vortex and the second atomizing medium vortex are opposite. The spray direction of the third spray unit is adapted to form a third atomized medium vortex, and the spray direction of the fourth spray unit is adapted to form a fourth atomized medium vortex, wherein the rotation directions of the third atomized medium vortex and the fourth atomized medium vortex are the same. The atomizing furnace is provided with an inner cylinder, a middle cylinder, and an outer cylinder. A partition is provided between the middle cylinder and the outer cylinder to divide the space into a first space and a second space. The second spray unit corresponds to the first space, and the fourth spray unit corresponds to the second space. A heating structure for heating the atomizing medium is provided in the first space, and a cooling structure for cooling the atomizing medium is provided in the second space.

2. The atomizer for improving the particle size uniformity of metal powder according to claim 1, characterized in that, The spraying directions of the first spraying unit, the second spraying unit, the third spraying unit, and the fourth spraying unit are all orthogonally decomposed into a first spraying direction along the liquid metal spraying direction and a second spraying direction that forms a vortex.

3. The atomizer for improving the particle size uniformity of metal powder according to claim 1, characterized in that, The space between the inner cylinder and the middle cylinder forms an atomizing space for atomizing the liquid metal jet; the space inside the inner cylinder and the space between the middle cylinder and the outer cylinder are used to transport the atomizing medium; the first injection unit and the third injection unit are disposed on the outer wall of the inner cylinder, and the second injection unit and the fourth injection unit are disposed on the inner wall of the middle cylinder.

4. The atomizer for improving the particle size uniformity of metal powder according to claim 3, characterized in that, The inner cylinder is connected to a first delivery pipe that provides atomizing medium. Multiple through holes are formed on the inner cylinder, which form the first injection unit and the third injection unit. The outer cylinder is connected to a second delivery pipe that provides atomizing medium. Multiple through holes are formed on the middle cylinder, which form the second injection unit and the fourth injection unit.

5. The atomizer for improving the particle size uniformity of metal powder according to claim 1, characterized in that, The heating structure is configured as an electric heating wire coiled and arranged in the first space.

6. The atomizer for improving the particle size uniformity of metal powder according to claim 1, characterized in that, The cooling structure is configured as a refrigerant pipe coiled and arranged in the second space.

7. The atomizer for improving the particle size uniformity of metal powder according to claim 4, characterized in that, The second delivery pipe has branch pipes that connect to the first space and the second space respectively.

Images