A centrifugal assisted laminar atomization device

Abstract

This application provides a centrifugal-assisted laminar atomization device, which relates to the field of additive manufacturing technology. By combining the centrifugal force generated by a centrifugal liquid distributor to assist the metal melt in forming a liquid film and then ejecting it, with the sonic airflow generated at the throat of the Laval nozzle and the supersonic airflow generated in the acceleration section, this overcomes the traditional laminar atomization's reliance on a small nozzle aperture, improves metal powder production efficiency, reduces the requirement for positive pressure driving the smelting chamber, and enhances operational safety.

Description

Technical Field

[0001] The present application relates to the field of additive manufacturing technology, and in particular to a centrifugal assisted laminar atomization device. Background Art

[0002] In recent years, the application of metal additive manufacturing technology in aerospace, automotive manufacturing, biomedicine, industrial molds, and other fields has continued to grow, and the consumption of powder raw materials required for metal additive manufacturing has also increased accordingly. As the performance requirements of metal additive manufacturing products in various fields increase, metal additive manufacturing technology also requires metal powder raw materials with narrower particle size distribution and finer particle size. Currently, iron-based, aluminum-based, copper-based, and nickel-based powders are generally produced using the vacuum induction melting inert gas atomization (VIGA) process. However, the particle size distribution of additive manufacturing metal powder raw materials produced by the VIGA process is relatively wide and the particle size is relatively coarse. The laminar flow gas atomization (LFGA) process based on the Laval nozzle can produce metal powders with a narrower particle size distribution and finer particle size. This laminar atomization process requires that the diameter of the liquid column in the guide tube be reduced to less than 2 mm, that is, the outlet aperture of the guide nozzle must be no larger than 2 mm. Therefore, the production efficiency of current laminar flow atomization equipment is relatively low. In actual applications, to ensure the smooth outflow of the molten metal in the guide nozzle, existing laminar flow atomization equipment requires a large driving positive pressure (such as high-pressure argon) above the melting chamber to allow the molten metal to pass through the guide nozzle outlet with an aperture of 1-2 mm. This design also poses a hidden danger to the sealing of the melting chamber and the safety of the atomization operation.

[0003] There is currently no effective technical solution to the above problems. Summary of the Invention

[0004] The purpose of this application is to provide a centrifugal assisted laminar atomization equipment, which, through the ingenious combination of a centrifugal liquid distributor and an atomizing spray disc, aims to improve the atomization efficiency without limiting the size of the guide nozzle, reduce the requirements for the driving pressure of the smelting chamber, and thus help reduce the safety hazards of the atomization work.

[0005] The present application provides a centrifugal assisted laminar atomization device, comprising a smelting chamber, an atomization chamber, a flow guide nozzle, an atomizing spray disc and a centrifugal liquid distributor;

[0006] The smelting chamber is used to prepare a metal melt, the atomizing chamber is arranged below the smelting chamber, the guide nozzle is arranged at the outlet of the smelting chamber and extends into the atomizing chamber, the guide nozzle is used to inject the metal melt into a centrifugal liquid distributor, and the centrifugal liquid distributor rotates to form a first liquid film on the metal melt under centrifugal force and throw it out;

[0007] The atomizing spray disc is coaxially arranged with the guide nozzle and is arranged around the centrifugal liquid distributor. The atomizing spray disc includes an upper cover and a lower cover. A Laval nozzle for the first liquid film to enter its throat is formed between the upper cover and the lower cover. An acceleration section is provided on the side of the Laval nozzle facing away from the centrifugal liquid distributor. The atomizing spray disc has a flow channel for conveying atomizing gas to the Laval nozzle. The atomizing gas reaches sonic speed at the throat of the Laval nozzle and acts on the first liquid film to form a thinner second liquid film. Subsequently, the atomizing gas enters the acceleration section, reaches supersonic speed, and simultaneously atomizes the second liquid film.

[0008] The clever combination of a centrifugal liquid distributor and an atomizing spray disc eliminates the need to limit the size of the guide nozzle, improves atomization efficiency, reduces the requirement for driving pressure in the melting chamber, and helps reduce safety hazards in atomization operations.

[0009] Optionally, a driving device is further included, wherein the centrifugal liquid distributor has a cavity and a rotating part that can rotate, the driving device is used to drive the rotating part to rotate, the cavity is provided with an annular gap, the cavity is used to receive the molten metal, the cavity is located on the upper surface of the rotating part, and the molten metal flowing into the cavity is subjected to the centrifugal force of the rotating part during rotation to form the first liquid film and is thrown out from the annular gap.

[0010] Through the above solution, a specific structure of the centrifugal liquid distributor is provided, which facilitates the realization of centrifugal liquid disposal.

[0011] Optionally, the centrifugal liquid distributor includes a guide portion, the rotating component is a turntable portion, the turntable portion is arranged below the guide portion, the guide portion and the turntable portion are enclosed to form the cavity, and the annular gap is formed between the edge position of the turntable portion and the guide portion, the cavity is connected to the annular gap, and the guide portion and the turntable portion are split structures.

[0012] Optionally, the centrifugal liquid distributor includes a guide portion, the rotating component is a turntable portion, the turntable portion is arranged below the guide portion, the guide portion and the turntable portion are enclosed to form the cavity, and the annular gap is formed between the edge position of the turntable portion and the guide portion, the cavity is connected to the annular gap, and the guide portion and the turntable portion are an integrally formed structure.

[0013] Optionally, the flow channel of the atomizing spray disc includes an upper flow channel and a lower flow channel. The upper flow channel is formed by the upper cover of the spray disc and the guide part, and the lower flow channel is formed by the lower cover of the spray disc and the turntable part. The atomizing gas flows into the Laval nozzle from the upper flow channel and the lower flow channel respectively, and the width of the upper flow channel and the lower flow channel gradually decreases in the direction approaching the Laval nozzle.

[0014] Through the above solution, a specific structure of the atomizing spray disc flow channel is provided, which optimizes the delivery and effect of the atomizing gas.

[0015] Optionally, the guide portion is a rotating body structure, the guide portion is trumpet-shaped, and the distance between the guide portion and the turntable portion gradually decreases radially outward.

[0016] Optionally, the guide portion and the spray plate upper cover are an integrally formed structure.

[0017] Optionally, the atomizing chamber is provided with a first return air device and / or a second return air device, the first return air device is arranged above the atomizing chamber and close to the smelting chamber, the first return air device is used to spray the non-uniform first gas downward, and the second return air device is arranged below the atomizing spray disc, and the second return air device is used to spray the second gas horizontally or upwardly.

[0018] Optionally, the first gas is a non-uniform gas.

[0019] Optionally, the direction of the second gas ejected from the second air return device is tilted upward, and the angle between the outlet of the second air return device and the horizontal plane is greater than 0° and less than or equal to 15°.

[0020] From the above, it can be seen that the centrifugal assisted laminar atomization equipment provided in this application, through the ingenious combination of the centrifugal liquid distributor and the atomizing spray disc, does not need to limit the outlet size of the guide nozzle, thereby improving the production efficiency of the centrifugal assisted laminar atomization equipment and reducing the requirements for the driving pressure of the smelting chamber, thereby improving the safety of the atomization operation.

[0021] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or understood by practicing the embodiments of the present application. The objectives and other advantages of the present application can be achieved and obtained through the structures particularly pointed out in the written description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a diagram of the overall structure of the centrifugal assisted laminar atomization equipment provided in an embodiment of the present application.

[0023] Figure 2Schematic diagram of the positions of the guide nozzle, atomizing spray disc and centrifugal liquid distributor provided in the embodiment of the present application.

[0024] Explanation of reference numerals: 100, melting chamber; 101, melting crucible; 102, tundish; 110, atomizing chamber; 120, guide nozzle; 130, atomizing spray disc; 131, spray disc upper cover; 132, spray disc lower cover; 133, throat; 134, acceleration section; 140, centrifugal liquid distributor; 141, guide section; 142, turntable section; 143, annular gap; 151, upper flow channel; 152, lower flow channel; 156, driving device; 171, first gas; 172, second gas; 173, cyclone separator; 174, dust collector; 175, return air fan; 180, third pipeline; 181, first powder collecting tank; 182, second powder collecting tank; 183, third powder collecting tank. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work fall within the scope of protection of the present application.

[0026] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0027] There are some technical problems in the traditional existing metal additive manufacturing powder preparation technology, especially the laminar atomization process based on the Laval nozzle. This process requires the diameter of the liquid column in the guide tube to be reduced to less than 2mm, which means that the outlet aperture of the guide nozzle must be no larger than 2mm. This small aperture limits the flow rate of the metal melt, resulting in low production efficiency of existing laminar atomization equipment. In order to overcome the resistance of the melt through such a small aperture, a large driving positive pressure, such as high-pressure argon, needs to be applied above the melting chamber. This high positive pressure operation not only increases the complexity and operating cost of the equipment, but also places extremely high demands on the sealing performance of the melting chamber and brings potential safety hazards during the atomization operation.

[0028] When faced with the above problems, this application first considers whether the efficiency can be improved by further optimizing the guide nozzle structure or increasing the gas pressure. However, simply increasing the aperture of the guide nozzle will destroy the liquid column shape and liquid column diameter required for laminar atomization, and fine powder cannot be obtained; and further increasing the gas pressure will increase safety risks and cost issues. In this regard, this application further explores a new melt pretreatment method, which aims to achieve efficient liquid distribution and pre-atomization of the metal melt without relying on small-aperture guide nozzles and high positive pressure, thereby providing a more suitable liquid film morphology and higher flow rate for subsequent supersonic gas atomization.

[0029] Please refer to Figure 1 and Figure 2 , Figure 1 This is a diagram of the overall structure of the centrifugal assisted laminar flow atomization equipment in some embodiments of the present application. This eliminates the need to limit the size of the guide nozzle 120, improves atomization efficiency, and reduces the driving pressure requirement for the smelting chamber 100, thereby helping to reduce safety hazards during atomization.

[0030] The present application provides a centrifugal assisted laminar atomization device, comprising: a smelting chamber 100, an atomization chamber 110, a flow guide nozzle 120, an atomizing spray disc 130 and a centrifugal liquid distributor 140;

[0031] The smelting chamber 100 is used to prepare a molten metal. The atomizing chamber 110 is disposed below the smelting chamber 100. The guide nozzle 120 is disposed at the outlet of the smelting chamber 100 and extends into the atomizing chamber 110. The guide nozzle 120 is used to inject the molten metal into the centrifugal liquid distributor 140. The centrifugal liquid distributor 140 rotates to form a first liquid film under the centrifugal force and then throws the molten metal out.

[0032] The atomizing spray disc 130 is coaxially arranged with the guide nozzle 120, and the atomizing spray disc 130 is arranged around the centrifugal liquid distributor 140. The atomizing spray disc 130 includes a spray disc upper cover 131 and a spray disc lower cover 132. A Laval nozzle for the first liquid film to enter its throat 133 is formed between the spray disc upper cover 131 and the spray disc lower cover 132. An acceleration section 134 is provided on the side of the Laval nozzle facing away from the centrifugal liquid distributor 140. The atomizing spray disc 130 has a flow channel for conveying atomizing gas to the Laval nozzle. The atomizing gas reaches the speed of sound at the throat 133 of the Laval nozzle and acts on the first liquid film to form a thinner second liquid film. Then the atomizing gas enters the acceleration section 134 to reach supersonic speed and simultaneously atomizes the second liquid film.

[0033] Among them, the driving device 156 can adopt a high-speed motor, but is not limited to this. The gas supply device can provide inert gas. The centrifugal liquid distributor 140 can include a rotating disc, the center of the disc receives the metal melt sent by the guide nozzle 120, and the disc rotates at high speed to throw the melt to the edge.

[0034] The core lies in the centrifugal liquid distributor 140, which rotates and uses centrifugal force to throw the molten metal out to form a first liquid film. Compared with traditional laminar atomization equipment that directly relies on pressure (the guide nozzle 120 requires 10-20 kPa and compensation pressure, where the compensation pressure is approximately 0.5 times the pressure of the atomizing gas) to extrude the molten metal, the centrifugal force of the centrifugal liquid distributor 140 of the present application can compensate for part of the pressure, without the need for compensation pressure, and the driving positive pressure of the guide nozzle 120 does not need to reach 10-20 kPa, thereby reducing the driving pressure of the smelting chamber, while increasing the flow rate and eliminating the need to limit the size of the guide nozzle 120 outlet. This helps reduce dependence on the smelting chamber pressure, thereby improving safety and creating more favorable conditions for subsequent atomization.

[0035] Among them, the Laval nozzle refers to a convergent-divergent channel formed on the atomizing spray disc 130, and its throat 133 receives the first liquid film thrown out. The flow channel of the atomizing spray disc 130 allows the atomizing gas flowing through to reach the speed of sound in the throat 133, which is mainly for the purpose of performing preliminary gas impact and breaking the first liquid film. The acceleration section 134 refers to the channel extending from the throat 133 of the Laval nozzle. Its structure allows the atomizing gas to further expand and accelerate in the channel to reach supersonic speed, which is mainly for providing supersonic airflow to efficiently atomize the second liquid film. The flow channel refers to the channel inside the atomizing spray disc 130 used to guide the atomizing gas to the Laval nozzle. It can be an annular channel or multiple independent channels, which is mainly for effectively transporting the atomizing gas to the atomizing area.

[0036] Specifically, the smelting chamber 100 is used to prepare a molten metal that requires atomization. The prepared molten metal is guided through the guide nozzle 120 to the centrifugal liquid distributor 140 located within the atomizing chamber 110 below. The centrifugal liquid distributor 140 is driven to rotate by a drive device 156. The injected molten metal spreads outward under the action of centrifugal force, forming a thin first liquid film that is ejected in a ring-shaped manner from the edge of the centrifugal liquid distributor 140. The atomizing spray disc 130 is coaxially arranged with the guide nozzle 120. The upper and lower covers 131 and 132 of the atomizing spray disc 130 respectively surround the guide portion 141 and the rotating disc portion 142 of the centrifugal liquid distributor 140 to form an annular Laval nozzle. The throat 133 of the Laval nozzle directly faces the first liquid film ejected by the centrifugal liquid distributor 140. An air supply device delivers atomizing gas to the flow channel of the atomizing spray disc 130, and the atomizing gas enters the Laval nozzle through the flow channel. At the throat 133 of the Laval nozzle, the atomizing gas is accelerated to the speed of sound, where it undergoes high-speed shearing and interaction with the first liquid film thrown out, causing a preliminary impact and breaking of the first liquid film, making it thinner and forming a second liquid film. The Laval nozzle is connected to an acceleration section 134 on the side facing away from the centrifugal liquid distributor 140. After passing through the throat 133 of the Laval nozzle, the atomizing gas enters the acceleration section 134, where it further expands and accelerates to reach a supersonic state. The supersonic atomizing gas flow violently shears and breaks the thinned second liquid film in the acceleration section 134, atomizing it into tiny metal droplets, which are then cooled and solidified in the atomization chamber to form metal powder. The entire process uses centrifugal force to assist in the distribution of the metal melt, reducing the requirements for the outflow pressure of the metal melt. At the same time, combined with efficient supersonic gas atomization, high-throughput, low-energy powder preparation is achieved.

[0037] Through the above solution, the present application improves the production efficiency of metal powder produced by the laminar atomization process, reduces the requirement for driving positive pressure of the smelting chamber 100, and thus improves the operational safety of the centrifugal assisted laminar atomization equipment.

[0038] In some embodiments, the smelting chamber 100 includes a smelting crucible 101 and a tundish 102. The smelting crucible 101 is used to smelt the metal mother material into a metal melt. The tundish 102 is used to hold the metal melt. The guide nozzle 120 is arranged below the tundish 102 to prepare the metal melt.

[0039] In some embodiments, a driving device 156 is also included. The centrifugal liquid distributor 140 has a cavity and a rotating part that can rotate. The driving device 156 is used to drive the rotating part to rotate. The cavity is provided with an annular gap 143. The cavity is used to receive the molten metal. The cavity is located on the upper surface of the rotating part. The molten metal flowing into the cavity is subjected to the centrifugal force of the rotating part during rotation to form a first liquid film and is thrown out from the annular gap 143.

[0040] Specifically, the metal melt is injected into the cavity of the centrifugal liquid distributor 140 from the guide nozzle 120, and the cavity serves as a receiving space to ensure that the metal melt can be collected inside the centrifugal liquid distributor 140. The rotating parts of the centrifugal liquid distributor 140 exert a centrifugal force on the metal melt in the cavity when rotating. The centrifugal force causes the melt to move toward the periphery of the cavity and forms a uniform liquid film at the edge of the cavity (the thickness of the liquid film generally does not exceed 0.5mm), that is, the first liquid film (the thickness of the first liquid film is determined by the thickness of the annular gap 143. The thickness of the annular gap 143 is pre-set according to the process requirements. In this application, the thickness of the annular gap 143 is preferably in the range of 0.3mm-1mm). The annular gap 143 set at the edge of the cavity serves as a preset liquid film outlet, so that the formed first liquid film can be stably thrown out from the gap in an annular form. This method of using centrifugal force to form a liquid film and eject it from the annular gap 143 overcomes the surface tension and viscosity of the melt, ensures the uniformity and stability of the liquid film, and provides a precise ejection position. Compared to relying solely on pressure to extrude the metal melt, the centrifugal force of the centrifugal liquid distributor 140 can assist or partially replace the driving pressure of the smelting chamber 100, thereby reducing the driving pressure required for the smelting chamber 100, while increasing the flow rate of the metal melt and eliminating the need to strictly limit the outlet size of the guide nozzle 120. This stable annular liquid film ejection is crucial for subsequent coordination with the Laval nozzle of the atomizing spray disc 130. It allows the centrifugal assisted laminar atomization equipment to operate at higher production efficiency, while reducing the requirement for the driving positive pressure of the smelting chamber 100 and improving the safety of the atomization operation.

[0041] In some embodiments, the centrifugal liquid distributor 140 includes a guide portion 141, and the rotating component is a turntable portion 142. The turntable portion 142 is arranged below the guide portion 141. The guide portion 141 and the turntable portion 142 are enclosed to form a cavity, and an annular gap 143 is formed between the edge position of the turntable portion 142 and the guide portion 141. The cavity is connected to the annular gap 143, and the guide portion 141 and the turntable portion 142 are split structures.

[0042] The split design of the guide portion 141 and the turntable portion 142, as well as the cavity and annular gap 143 formed by the two, achieves stable liquid distribution and ejection of the molten metal. Specifically, the guide nozzle 120 introduces the molten metal into the cavity formed by the guide portion 141 and the turntable portion 142, and the turntable portion 142 rotates at high speed, causing the molten metal in the cavity to form a liquid film under the action of centrifugal force, and finally forms a first liquid film at the edge of the centrifugal liquid distributor 140. That is, the centrifugal liquid distributor 140 can transform the large-diameter and large-flow molten metal at the outlet of the guide nozzle 120 into a thinner melt liquid film (i.e., the thickness of the liquid film generally does not exceed 0.5mm), allowing the centrifugal assisted laminar atomization equipment to operate at a higher production efficiency, while reducing the driving positive pressure of the smelting chamber 100 and improving the safety of the atomization operation. The split structural design allows the guide portion 141 and the turntable portion 142 to be optimized and manufactured separately.

[0043] As a specific implementation, the centrifugal liquid distributor 140 can be composed of a guide portion 141 in the shape of an inverted cone or trumpet and a disc-shaped turntable portion 142. The outer edge of the guide portion 141 and the spray disc cover 131 of the atomizing spray disc 130 are enclosed to form a flow channel for conveying atomizing gas to the Laval nozzle, and the outer edge of the guide portion 141 and the spray disc cover 131 of the atomizing spray disc 130 are integrally formed, such as Figure 2 As shown, the turntable portion 142 (ie, a rotatable component) is disposed below the guide portion 141 , and the turntable portion 142 is connected to the driving device 156 (may be connected via a coupling or a tool handle, etc.).

[0044] In some embodiments, the centrifugal liquid distributor 140 includes a guide portion 141, and the rotating component is a turntable portion 142. The turntable portion 142 is arranged below the guide portion 141. The guide portion 141 and the turntable portion 142 are enclosed to form a cavity, and an annular gap 143 is formed between the edge position of the turntable portion 142 and the guide portion 141. The cavity is connected to the annular gap 143. The guide portion 141 and the turntable portion 142 are an integrally formed structure (the guide portion 141 and the turntable portion 142 are connected by an axially symmetrical connecting column (support column), and the specific connection method is not limited here).

[0045] Specifically, by adopting an integrally formed structure, the centrifugal liquid distributor 140 of the present application effectively avoids the problems of loose connections, high-temperature deformation, and sealing difficulties caused by a split structure, significantly improving the structural stability of the centrifugal liquid distributor 140, the uniformity of the metal melt flow, and the uniformity and stability of the first liquid film. This enables the centrifugal liquid distributor 140 to stably and reliably form a high-quality liquid film under the condition of a large flow rate of metal melt input, providing good initial conditions for the subsequent laminar atomization process, helping to improve atomization efficiency and powder quality, while reducing the requirement for positive pressure to drive the smelting chamber 100 and improving the safety of the atomization operation.

[0046] In some embodiments, the flow channel of the atomizing spray disc 130 includes an upper flow channel 151 and a lower flow channel 152. The upper flow channel 151 is formed between the spray disc upper cover 131 and the guide portion 141, and the lower flow channel 152 is formed between the spray disc lower cover 132 and the turntable portion 142. The atomizing gas flows into the Laval nozzle from the upper flow channel 151 and the lower flow channel 152 respectively, and the width of the upper flow channel 151 and the lower flow channel 152 gradually decreases in the direction approaching the Laval nozzle.

[0047] Specifically, through this contraction design, the atomized gas is gradually accelerated before entering the Laval nozzle, which increases the kinetic energy of the gas, helps to stabilize the gas flow state, and reduces turbulence. The accelerated atomized gas converges from the upper flow channel 151 and the lower flow channel 152 respectively to form a horizontal laminar atomized gas that reaches the speed of sound at the throat 133 of the Laval nozzle and acts on the first liquid film at the same time, causing the first liquid film to be further broken up to form a thinner second liquid film. Subsequently, the atomized gas enters the acceleration section 134 on the side of the Laval nozzle facing away from the centrifugal liquid distributor 140, reaches supersonic speed in the acceleration section 134, and simultaneously performs supersonic atomization on the second liquid film, eventually forming fine metal powder. This structural design, combined with the structure of the centrifugal liquid distributor 140, makes the formation of the gas flow channel more reasonable and precise, and ultimately helps to obtain metal powder with a narrower particle size distribution and finer particle size, thereby improving the powder quality.

[0048] In some embodiments, the guide portion 141 is a rotating body structure, the guide portion 141 is trumpet-shaped, and the distance between the guide portion 141 and the turntable portion 142 gradually decreases radially outward.

[0049] Specifically, the centrifugal liquid distributor 140 of the present application optimizes the flow of the metal melt in the centrifugal liquid distributor 140 and the formation and ejection of the first liquid film by making specific restrictions on the structure of the guide portion 141 and the turntable portion 142, and further improves the flow state of the atomizing gas. The guide portion 141 is designed as a rotating body structure, which ensures that the entire centrifugal liquid distributor 140 has good dynamic balance and structural stability when rotating at high speed. At the same time, its rotational symmetry matches the centrifugal liquid ejection process, which helps to form a uniformly distributed first liquid film. The guide portion 141 is trumpet-shaped, and its outer surface and the spray disc upper cover 131 of the atomizing spray disc 130 together constitute the upper flow channel 151 of the atomizing gas. The trumpet-shaped profile can smoothly guide the atomizing gas into the upper flow channel 151, and make its flow state more stable in the process of flowing to the Laval nozzle, reduce turbulent losses, and facilitate gas acceleration. The distance between the guide portion 141 and the turntable portion 142 gradually decreases radially outward. When the metal melt flows toward the channel under the action of centrifugal force, the melt flow rate will gradually increase due to the gradual decrease in the cross-sectional area of ​​the channel, and at the same time, it will be forced to shrink into a thinner liquid film. In addition, the relative position and shape between the guide portion 141 and the turntable portion 142 also affect the shape of the lower flow channel 152 adjacent to the turntable portion 142, and work together with the lower cover 132 of the atomizing spray disc 130 to further optimize the flow and acceleration process of the atomizing gas in the lower flow channel 152. Through the coordinated cooperation of these structures, the present solution can more accurately control the formation of the first liquid film and the shape of the flow channel, thereby optimizing the acceleration effect of the gas at the Laval nozzle and the interaction efficiency with the first liquid film, thereby improving the overall atomization performance.

[0050] In some embodiments, the guide portion 141 and the spray plate upper cover 131 are integrally formed.

[0051] Specifically, by integrally forming the guide portion 141 with the spray disc cover 131, the inherent fitting errors and sealing risks of a separate structure are eliminated. This resulting structure has greater overall rigidity and dimensional stability, ensuring a more precise and stable shape for the upper flow channel 151. This allows the atomizing gas to flow to the Laval nozzle in a smoother and more controlled manner, contributing to a more stable and efficient laminar atomization process. The guide portion 141 and the spray disc cover 131 are constructed as a single unit directly from the design model using additive manufacturing techniques, such as metal 3D printing, without specific limitations herein.

[0052] In some embodiments, the thickness of the annular gap 143 ranges from 0.3 mm to 1 mm.

[0053] This solution limits the thickness range of the annular gap 143 to 0.3mm-1mm. By controlling the size of the annular gap 143, it can be ensured that the metal melt can smoothly and evenly form a first liquid film under the action of centrifugal force, thereby providing a good foundation for the subsequent atomization process. Specifically, when the size of the annular gap 143 is less than 0.3mm, the metal melt is easily obstructed during the flow process, resulting in an uneven liquid film, or even unable to form a continuous liquid film, affecting the atomization effect. When the size of the annular gap 143 is greater than 1mm, the liquid film formed by the metal melt is too thick, which increases the difficulty of subsequent atomization, resulting in an increase in powder particle size and uneven distribution. Therefore, limiting the size of the annular gap 143 to within the range of 0.3mm-1mm can effectively solve the above problems and ensure that the metal melt can smoothly form a uniform first liquid film, thereby improving the atomization efficiency and powder quality.

[0054] In some embodiments, the atomizing chamber 110 is provided with a first return air device and / or a second return air device. The first return air device is arranged above the atomizing chamber 110 and close to the smelting chamber 100, and the first return air device is used to spray the first gas 171 downward. The second return air device is arranged below the atomizing spray disk 130, and the second return air device is used to spray the second gas 172 horizontally or upwardly.

[0055] This solution aims to reduce the size of the atomizing chamber 110 and suppress the satellite powder yield by arranging a first return air device and / or a second return air device in the atomizing chamber 110 . Specifically, a large number of tiny molten droplets and supersonic airflow generated by the atomization operation form a gas-liquid mixed flow that diffuses outward. At the same time, the tiny molten droplets are continuously cooled and cooled by convection and radiation, and finally produce metal powder with finer particle size and narrower particle size distribution. By setting a first return air device, the horizontal airflow ejected from the Laval nozzle is forced to flow downward, which is beneficial to reducing the radial size of the atomizing chamber 110. At the same time, a second return air device is also set below the atomizing spray disc 130. The second gas 172 is used to replenish air to the gas-liquid mixed flow or the gas-solid mixed flow to prevent the solidified powder in the atomizing chamber 110 from being carried into the air flow mixed flow by the upward airflow (the gas-liquid mixed flow or the gas-solid mixed flow will suck the surrounding air during the flow process, so that the gas at the bottom of the atomizing chamber 110 carries the solidified powder upward under the action of suction and thermal buoyancy, thereby increasing the satellite powder yield). By setting a second return air device to spray the second gas 172, this upward airflow can be effectively suppressed, thereby reducing the generation of satellite powder. The first air return device and the second air return device work together to optimize the air flow field in the atomizing chamber 110, effectively control the movement trajectory of the powder, and solve the problems of powder backflow and satellite powder.

[0056] In some embodiments, the first gas 171 is a non-uniform gas.

[0057] Specifically, a non-uniform gas flow refers to a gas whose velocity gradually increases along the flow direction of the gas-liquid mixed flow. After the tiny molten droplets cool and solidify, the first gas 171 forces the gas-solid mixed flow (the molten droplets cool and solidify into metal powder, forming a gas-solid mixed flow, i.e., the airflow carrying the metal powder) to deflect downward, thereby facilitating subsequent powder collection. In practical applications, the first return air device can include an annular nozzle positioned at the top of the atomizing chamber 110, surrounding the central axis of the guide nozzle 120 and the atomizing disk 130. The outlet of this annular nozzle can be designed to have varying slit widths or angles along the radial direction, thereby ejecting the first gas 171 with a non-uniform radial velocity or flow distribution. For example, areas near the central axis can be designed to eject gas at a lower velocity, while areas farther from the central axis can eject gas at a higher velocity, or vice versa, to create a desired airflow profile. This non-uniform airflow, ejected downward, interacts with the high-speed atomizing gas ejected from the atomizing disk 130 and the atomized molten metal, shaping the airflow field within the atomizing chamber 110.

[0058] The first air return device and the second air return device can both be implemented by using an annular nozzle or multiple independent nozzles.

[0059] In some embodiments, the direction of the second gas 172 ejected from the second air return device is tilted upward, and the angle between the outlet of the second air return device (i.e., the center line of the ejection direction of the second gas 172) and the horizontal plane is greater than 0° and less than or equal to 15°.

[0060] This solution further specifies that the second gas 172 is ejected upward at an angle between 0° and 15°. This upward angle is designed to replenish the second gas 172 to the gas-liquid or gas-solid mixed flow, preventing solidified powder in the atomization chamber 110 from being displaced by the upward airflow into the mixed flow (the gas-liquid or gas-solid mixed flow will entrain surrounding air during its flow, causing the gas in the lower portion of the atomization chamber 110 to carry solidified powder upward due to entrainment and thermal buoyancy, increasing the satellite powder yield), thereby reducing the satellite powder yield.

[0061] In some embodiments, the first air return device and the second air return device are both connected to the air return system of the atomization chamber 110 , and the air return system is used to provide gas to the first air return device and the second air return device.

[0062] Specifically, the return air system of the atomizing chamber 110 provides gas to the first return air device and the second return air device. Since the temperature of the gas is relatively high, the temperature drop of the atomizing chamber can be reduced, which is beneficial to ensuring the sphericity of the powder.

[0063] In some embodiments, the return air system includes a cyclone separator 173, a dust collector 174 and a return air fan 175. The side of the atomizing chamber 110 is connected to the cyclone separator 173 through a first pipe, and the top of the cyclone separator 173 is connected to the dust collector 174 through a second pipe. The return air fan 175 is connected to the dust collector 174. The return air fan 175 is used to pressurize the gas discharged from the dust collector 174 and is connected to the first return air device and the second return air device through a third pipe 180, as shown in FIG. Figure 1 shown.

[0064] In some embodiments, a first powder collecting tank 181, a second powder collecting tank 182, and a third powder collecting tank 183 are further included. The first powder collecting tank 181 is arranged below the outlet of the atomization chamber 110 and is connected to the outlet of the atomization chamber 110. The second powder collecting tank 182 is arranged below the cyclone separator 173, and the third powder collecting tank 183 is arranged below the dust collector 174. The first powder collecting tank 181 is used to collect powder in the atomization chamber 110, the second powder collecting tank 182 is used to collect powder in the cyclone separator 173, and the third powder collecting tank 183 is used to collect powder in the dust collector 174.

[0065] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any actual relationship or order between these entities or operations.

[0066] The above description is merely an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, various modifications and variations of the present application are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A centrifugal assisted laminar atomization device, characterized in that: include: A smelting chamber (100), an atomizing chamber (110), a flow guide nozzle (120), an atomizing spray disc (130), and a centrifugal liquid distributor (140); The smelting chamber (100) is used to prepare a metal melt, the atomizing chamber (110) is arranged below the smelting chamber (100), the guide nozzle (120) is arranged at the outlet of the smelting chamber (100) and extends into the atomizing chamber (110), the guide nozzle (120) is used to inject the metal melt into the centrifugal liquid distributor (140), and the centrifugal liquid distributor (140) rotates to form a first liquid film on the metal melt under the centrifugal force and throw it out; The atomizing spray disc (130) is coaxially arranged with the guide nozzle (120), and the atomizing spray disc is arranged around the centrifugal liquid distributor (140). The atomizing spray disc (130) includes a spray disc upper cover (131) and a spray disc lower cover (132). A Laval nozzle is formed between the spray disc upper cover (131) and the spray disc lower cover (132). The throat (133) of the Laval nozzle is for the first liquid film to enter. An acceleration section (134) is provided on the side of the Laval nozzle facing away from the centrifugal liquid distributor (140). The atomizing spray disc (130) has a flow channel for conveying atomizing gas to the Laval nozzle. The atomizing gas reaches sonic velocity at the throat (133) of the Laval nozzle and acts on the first liquid film to form a thinner second liquid film. Subsequently, the atomizing gas enters the acceleration section (134) to reach supersonic velocity and simultaneously atomizes the second liquid film. The centrifugal liquid distributor (140) further comprises a driving device (156), wherein the centrifugal liquid distributor (140) comprises a cavity and a rotating component capable of rotating, wherein the driving device (156) is used to drive the rotating component to rotate, wherein the cavity is provided with an annular gap (143), wherein the cavity is used to receive the molten metal, wherein the cavity is located on the upper surface of the rotating component, and the molten metal flowing into the cavity is subjected to the centrifugal force of the rotating component during rotation to form the first liquid film and is thrown out from the annular gap (143).

2. The centrifugal assisted laminar atomization device according to claim 1, characterized in that: The centrifugal liquid distributor (140) includes a guide portion (141), the rotating component is a turntable portion (142), the turntable portion (142) is arranged below the guide portion (141), the guide portion (141) and the turntable portion (142) enclose the cavity, and the annular gap (143) is formed between the edge of the turntable portion (142) and the guide portion (141), the cavity is connected to the annular gap (143), and the guide portion (141) and the turntable portion (142) are separate structures.

3. The centrifugal assisted laminar atomization device according to claim 1, characterized in that: The centrifugal liquid distributor (140) comprises a guide portion (141), the rotating component is a turntable portion (142), the turntable portion (142) is arranged below the guide portion (141), the guide portion (141) and the turntable portion (142) enclose to form the cavity, and an annular gap (143) is formed between the edge of the turntable portion (142) and the guide portion (141), the cavity is connected to the annular gap (143), and the guide portion (141) and the turntable portion (142) are an integrally formed structure.

4. The centrifugal assisted laminar atomization device according to claim 2, characterized in that: The flow channel of the atomizing spray disc (130) includes an upper flow channel (151) and a lower flow channel (152), wherein the upper flow channel (151) is enclosed between the spray disc upper cover (131) and the guide portion (141), and the lower flow channel (152) is enclosed between the spray disc lower cover (132) and the turntable portion (142), and the atomizing gas flows into the Laval nozzle from the upper flow channel (151) and the lower flow channel (152) respectively, and the widths of the upper flow channel (151) and the lower flow channel (152) gradually decrease in a direction approaching the Laval nozzle.

5. The centrifugal assisted laminar atomization device according to claim 2 or 3, characterized in that: The guide portion (141) is a rotating body structure, the guide portion (141) is trumpet-shaped, and the distance between the guide portion (141) and the turntable portion (142) gradually decreases radially outward.

6. The centrifugal assisted laminar atomization device according to claim 4, characterized in that: The guide portion (141) and the spray plate upper cover (131) are an integrally formed structure.

7. The centrifugal assisted laminar atomization device according to claim 1, characterized in that: The atomizing chamber (110) is provided with a first return air device and / or a second return air device, wherein the first return air device is provided above the atomizing chamber (110) and close to the smelting chamber (100), and is used to spray the first gas (171) downward, and the second return air device is provided below the atomizing spray disc (130), and is used to spray the second gas (172) horizontally or upwardly.

8. The centrifugal assisted laminar atomization device according to claim 7, characterized in that: The first gas (171) is a non-uniform gas.

9. The centrifugal assisted laminar atomization device according to claim 8, characterized in that: The direction of the second gas (172) ejected from the second air return device is tilted upward, and the angle between the outlet of the second air return device and the horizontal plane is greater than 0° and less than or equal to 15°.

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