Spheroidizing system for flame-processed high-sphericity powders and semiconductor filler materials

Abstract

This invention discloses a spheroidizing system and semiconductor filler material for preparing high-sphericity powders using a flame method. The spheroidizing system includes a feeding device, a material dispersing device, and a flame combustion device connected in sequence. The material dispersing device is configured to form a multi-stage airflow shear field internally. The flame combustion device includes a combined combustion nozzle and a throat sleeved outside the combined combustion nozzle. The feed end of the throat is connected to the material outlet of the material dispersing device. By applying an airflow shear field of a specific structure within a very short path or instant before the powder enters the high-temperature zone of the flame, the powder clusters in the conveying airflow are strongly, online, and instantly deagglomerated, maintaining their single-particle dispersion state until they enter the high-speed jet of flame, thereby improving the quality of the spherical powder.

Description

Technical Field

[0001] This invention relates to the field of powder material preparation technology, and more specifically, to a spheroidizing system and semiconductor filler material for preparing high sphericity powder by flame method. Background Technology

[0002] Spherical powders, due to their excellent flowability, high bulk density, low specific surface area, and isotropy, exhibit irreplaceable advantages in many high-end fields (such as metal / ceramic additive manufacturing (3D printing), precision injection molding (MIM), thermal spraying, electronic packaging, high-end catalysts, and biomedical carriers), representing a high-end form of powder material application. Flame processing (including plasma torches and high-temperature combustion flames) is a key process for achieving efficient and high-purity spheroidization of refractory materials (such as metals, ceramics, and carbides). The principle involves feeding the raw (usually irregularly shaped) powder into a high-temperature flame zone, where the material melts instantly and spheroidizes under surface tension, subsequently rapidly cooling and solidifying into spherical particles.

[0003] The core indicators for preparing high-quality spherical powders using the flame method (sphericity, sphericity, and particle size distribution uniformity) are highly dependent on the dispersion state of the material before it enters the high-temperature flame zone. An ideal dispersion state requires the material particles to enter the flame core zone as single particles, highly discrete, and spatially uniformly distributed. Currently used pneumatic conveying methods (such as Venturi tubes and fluidized bed ejectors) have significant shortcomings when processing fine powders (especially in the submicron to tens of micron range): uneven dispersion makes it difficult to achieve ideal uniform distribution of single particles in the conveying airflow, especially in the instant before entering the flame nozzle. Powders easily form concentration gradients or localized agglomeration at pipes and nozzles; particle adhesion is severe. Due to van der Waals forces and electrostatic adsorption, fine powders are prone to inter-particle adhesion and agglomeration during transport, forming "soft agglomerates" or even "hard agglomerates," such as... Figure 1 As shown.

[0004] The above-mentioned problem of insufficient dispersibility directly leads to the following serious defects in the flame spheroidization process: (1) "Grape bunch" agglomerates: the adhering particle agglomerates may not be able to fully separate and melt in the flame, eventually forming a "grape bunch" structure with multiple small balls adhering together, which seriously reduces the spheroidization rate and sphericity; (2) "Merged combustion" and abnormal particle size: the tightly adhering particles may first melt into a large droplet at high temperature and then spheroidize, or multiple small droplets may collide and merge during flight, resulting in the generation of large balls that are far larger than the target particle size. This not only causes a significant widening of the particle size distribution (PSD) (with the appearance of coarse outlier particles), but also leads to a decrease in the yield of fine powder and a deterioration in the consistency of product batches; (3) Incomplete spheroidization: the particles inside the agglomerates may not be completely spheroidized due to uneven heating or insufficient melting time, leaving residual edges and affecting the flowability and other properties of the final product.

[0005] Although attempts have been made to add mechanical dispersion (such as stirring, vibrating screen) or airflow-assisted dispersion devices to the conveying path, these methods are often inefficient, prone to introducing pollution, and difficult to achieve stable, efficient, and pollution-free online instant dispersion at the critical node where materials enter the flame zone at high speed. They cannot fundamentally solve the above-mentioned problems of adhesion and uneven dispersion.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a spheroidizing system and a semiconductor filler material for preparing high sphericity powders by flame method, so as to improve the above-mentioned technical problems.

[0008] This invention is implemented as follows:

[0009] In a first aspect, the present invention provides a spheroidizing system for preparing high sphericity powder by flame method, comprising a feeding device, a material dispersing device and a flame combustion device connected in sequence, wherein the material dispersing device is configured to form a multi-stage airflow shear field inside, and the flame combustion device includes a combined combustion nozzle and a throat sleeved outside the combined combustion nozzle, wherein the feeding end of the throat is connected to the material outlet of the material dispersing device.

[0010] In an optional embodiment, the combined combustion gun is positioned at the center of the throat, and the throat has an annular protrusion corresponding to the position of the combined combustion gun nozzle. The annular protrusion and the inner wall of the throat together form a continuous and axially symmetrical Venturi nozzle flow channel.

[0011] In an optional embodiment, the material dispersing device includes a feeding funnel, a dispersing mechanism, and an air collecting ring; the bottom of the feeding funnel has a material conveying air jet port on one side, and the bottom of the feeding funnel opposite to the material conveying air jet port is provided with a material conveying channel communicating with the dispersing mechanism; the dispersing mechanism has a cylindrical dispersing cavity inside, and the air collecting ring has multiple air outlet pipes arranged around its circumference, which are connected to the side wall of the dispersing mechanism and communicate with the dispersing cavity; the central area of ​​the dispersing cavity is connected to the throat pipe through a pipe.

[0012] In an optional embodiment, the gas collecting ring is located below the dispersing mechanism, and the top central region of the dispersing chamber is connected to the throat tube via a pipe.

[0013] And / or, the connection points of the plurality of air outlet pipes with the dispersing chamber are located at the same horizontal height of the dispersing chamber and are evenly spaced along the peripheral wall of the dispersing chamber, and the air outlet direction of the plurality of air outlet pipes is at the same angle to the peripheral wall of the dispersing chamber and is 40~60 degrees.

[0014] And / or, the gas collecting ring is also equipped with a pressure monitoring instrument.

[0015] In an optional embodiment, the feeding device includes a raw material bin, and a feeding impeller is provided at the bottom outlet of the raw material bin.

[0016] In an optional embodiment, the combined combustion nozzle includes an oxygen inlet pipe and a gas inlet pipe. The gas inlet pipe is sleeved outside the oxygen inlet pipe. The inner wall of the gas inlet pipe and the outer wall of the oxygen inlet pipe together form a gas passage. An oxygen interface is provided at the end of the oxygen inlet pipe, and a gas interface is provided at the end of the gas inlet pipe.

[0017] In an optional embodiment, it further includes a cyclone collecting device, the inlet of which is connected to the outlet of the flame combustion device, the bottom of which is provided with a coarse powder discharge port, and the top of which is provided with a gas outlet.

[0018] In an optional embodiment, a makeup air filter box for makeup air is also provided on the connecting pipe between the cyclone collecting device and the flame combustion device.

[0019] In an optional embodiment, it further includes a bag collection device, wherein the gas outlet of the cyclone collection device is connected to the inlet of the bag collection device, the bottom of the bag collection device is provided with a fine powder discharge port, and the top outlet of the bag dust collector is connected to a centrifugal fan.

[0020] In an optional embodiment, a cooling water baffle is also provided outside the throat, the cooling water baffle fully covering the flame spray area of ​​the combined combustion gun, and a cooling water inlet and a cooling water outlet are respectively provided at both ends of the cooling water baffle.

[0021] In a second aspect, the present invention also provides a semiconductor filler material, characterized in that it is prepared from raw materials with a particle size D50 of 1~10μm through the aforementioned spheroidizing system for preparing high sphericity powder by flame method, and the specific surface area of ​​the semiconductor filler material is 0.5~8cm² / g.

[0022] The present invention has the following beneficial effects:

[0023] Within a very short travel distance before the powder enters the high-temperature zone of the flame, a multi-stage enhanced shear airflow field is constructed. High-speed, multi-directional, turbulent airflow is used to subject the powder to intense shearing and dispersion. This allows for powerful, online, and real-time deagglomeration of powder clusters carried in the conveying airflow, effectively maintaining their individual particle dispersion until they enter the high-speed jet flame zone. This significantly improves the core process conditions of the spheroidization process. The resulting technical effects include: significantly suppressing the formation of incompletely melted agglomerates resembling "grape bunches"; promoting the evolution of individual particles towards an ideal spherical morphology; effectively eliminating abnormally large particles caused by local adhesion or merging, obtaining products with concentrated particle size distribution that meet target specifications (e.g., controllable D50 adjustment and significantly reduced Span value); reducing the proportion of defective products (such as agglomerates and oversized particles), increasing the yield of products meeting fine powder specifications, and thus reducing overall production costs.

[0024] Furthermore, this method exhibits excellent batch stability: thanks to the high controllability and repeatability of the dispersion process, product performance and batch-to-batch quality consistency are significantly enhanced. This technology also has broad applicability, compatible with various material systems (such as metals, ceramics, and inorganic non-metallic materials) and a wide range of original particle size distributions, making it particularly suitable for flame spheroidization of fine powders that are difficult to process effectively using traditional methods. Notably, it employs a purely physical mechanism for dispersion, which can reduce or even eliminate the use of chemical dispersants to some extent, thereby reducing the risk of introducing exogenous impurities and improving the purity and environmental friendliness of the final product. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram illustrating the adhesion, aggregation, and poor spheroidization results caused by conventional airflow transport in existing technologies.

[0027] Figure 2 This is a schematic diagram of the spheroidizing system for preparing high sphericity powder by flame method according to an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the vertical cross-sectional structure of the material dispersing device according to an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of the horizontal cross-sectional structure of the material dispersing device's dispersing mechanism according to an embodiment of the present invention.

[0030] Figure 5 This is a schematic diagram of a spheroidizing system for preparing high-sphericity powders using the flame method, as described in an embodiment of the present invention, to obtain powders with high sphericity and narrow distribution.

[0031] Icons: 10 - Spheroidizing system for flame method preparation of high sphericity powder; 100 - Feeding device; 110 - Raw material bin; 120 - Feeding impeller; 200 - Material dispersion device; 210 - Feeding funnel; 211 - Material conveying channel; 220 - Dispersion mechanism; 230 - Gas collecting ring; 231 - Pressure monitoring instrument; 201 - Material conveying gas nozzle; 202 - Main air inlet; 203 - Dispersion chamber; 240 - Gas outlet pipe; 3 00-Flame combustion device; 310-Combined combustion nozzle; 311-Gas inlet pipe; 312-Oxygen inlet pipe; 301-Gas interface; 302-Oxygen interface; 320-Throat; 321-Annular protrusion; 322-Cooling water jacket; 330-Make-up air filter box; 331-Make-up air proportional valve; 400-Cyclone separator; 410-Air shut-off valve; 500-Bag collection device; 600-Centrifugal fan; 601-Exhaust port. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0034] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0035] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0036] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0037] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0038] The following detailed description, through examples and in conjunction with the accompanying drawings, details the overall structure, working principle, and technical effects of a spheroidizing system 10 for preparing high-sphericity powders by flame method provided by the present invention.

[0039] See appendix Figure 2 The present invention provides a spheroidizing system 10 for preparing high sphericity powder by flame method, which includes a feeding device 100, a material dispersing device 200 and a flame combustion device 300 connected in sequence. The material dispersing device 200 is configured to form a multi-stage airflow shear field inside. The flame combustion device 300 includes a combined combustion nozzle and a throat 320 sleeved outside the combined combustion nozzle 310. The feeding end of the throat 320 is connected to the material outlet of the material dispersing device 200.

[0040] Specifically, the feeding device 100 includes a raw material silo 110, with a feeding impeller 120 installed at the bottom outlet of the raw material silo 110. The raw material silo 110 is generally a vertical cylindrical section with a conical bottom, the angle of which is 30°~60°, preferably 45°, and its volume is matched according to the production capacity. The cylindrical section ensures storage capacity, while the conical bottom utilizes gravity to promote flow. If the cone angle is too small, bridging is likely; if it is too large, material is likely to be swept away. The feeding impeller 120 installed at the bottom outlet of the raw material silo 110 can break up powder bridging, achieve precise quantitative unloading, and ensure that the powder enters the subsequent material dispersion device 200 uniformly, especially suitable for 5~100μm powders with poor flowability and easy agglomeration.

[0041] The material dispersion device 200 mainly consists of three parts: a feeding funnel 210, a dispersing mechanism 220, and a gas collecting ring 230. The discharge port of the feeding impeller 120 is located above the feeding funnel 210, and the material falls naturally into the funnel under gravity. In other embodiments, it can also be directly connected to the inlet of the feeding funnel 210 through a pipe, thereby effectively preventing material leakage or scattering.

[0042] The bottom structure of the feeding hopper 210 is designed as follows: one side is provided with a material conveying air jet nozzle 201, and the opposite side is provided with a material conveying channel 211 connected to the dispersing mechanism 220. The specific working process is as follows: after the material is deposited at the bottom of the feeding hopper 210 under the action of gravity, the high-speed airflow ejected by the material conveying air jet nozzle 201 pushes the material through the material conveying channel 211 into the dispersing mechanism 220 to complete the subsequent dispersion processing.

[0043] See Figure 3 The material conveying channel 211 has a Venturi tube shape, which facilitates the formation of a strong turbulent field within the channel, thereby effectively dispersing the material and completing its initial pre-dispersion treatment before entering the dispersing mechanism 220. The dispersing mechanism 220 has a cylindrical dispersing chamber 203 inside. The material, after being pre-dispersed by the material conveying channel 211, enters the chamber tangentially along the cylindrical inner wall of the dispersing chamber 203 and moves towards the central area under the combined action of centrifugal force and airflow disturbance, thus achieving secondary crushing and further dispersal of the material, significantly improving the dispersion effect and processing uniformity.

[0044] The gas collecting ring 230 is linked to the dispersing mechanism 220 through a pressure regulation mechanism, thereby precisely controlling the dispersing or crushing intensity of the material. The gas collecting ring 230 adopts a ring-shaped tubular structure design and is fixedly connected to the dispersing mechanism 220 by a rigid support (see details). Figure 3 , Figure 4 In terms of structural configuration, a main air inlet 202 is provided on one side of the air collecting ring 230, and multiple air outlet pipes 240 are evenly distributed around its circumference. These air outlet pipes 240 are connected to the side wall of the dispersing mechanism 220 in an equally spaced manner, and communicate with the inner cavity of the dispersing chamber 203.

[0045] In practice, all interfaces between the air outlet pipes 240 and the dispersing chamber 203 are located on the same horizontal plane and are evenly distributed along the periphery of the chamber. The air outlet direction of each air outlet pipe 240 forms an angle of 40-60 degrees with the periphery of the dispersing chamber 203, preferably using a uniform standard angle value. Through this design, multiple airflows are input in the same direction along the periphery of the chamber, working in synergy with the material conveying airflow to form a high-speed, multi-directional turbulent field within the dispersing chamber 203, achieving efficient shearing and dispersion of powder materials.

[0046] The central area of ​​the dispersing chamber 203 is connected to the throat 320 of the flame combustion device 300 via a dedicated pipe. After the material is fully dispersed in the chamber, it will converge towards the center of the chamber under the guidance of the airflow from the gas collecting ring 230, and finally be transported to the throat 320 of the flame combustion device 300 for combustion via a dedicated pipe. The material entering the throat 320 is already in a uniform atomized state, and the flow rate can be controlled to be approximately 8~15m / s.

[0047] Furthermore, see again Figure 2 The gas collecting ring 230 is installed below the dispersing mechanism. The top center area of ​​the dispersing chamber 203 is directly connected to the throat 320 of the flame combustion device 300 via a bent pipe. The bottom of the bent pipe is connected to the top of the dispersing mechanism 220 via a flange. The other end of the bent pipe is integrally formed with the throat 320, and the overall length of the bent pipe is relatively short to ensure the uniformity of the material. The gas collecting ring 230 also serves a supporting function in its structure, while guiding the gas to carry the material out from the top. It should be noted that, in order to achieve precise control of the pressure of the gas collecting ring 230 and thus accurately control the material dispersing intensity, the device is also equipped with a pressure monitoring instrument 231.

[0048] It should be noted that the gas introduced into the material conveying gas jet 201 and the gas introduced into the main air inlet 202 of the gas collecting ring 230 are both air. Of course, in some other embodiments, inert gases such as nitrogen can also be selected according to the subsequent flame combustion.

[0049] Furthermore, in this embodiment, the combined combustion nozzle 310 is positioned at the center of the throat 320. An annular protrusion 321 is provided on the throat 320 corresponding to the nozzle of the combined combustion nozzle 310. The annular protrusion 321 and the inner wall of the throat 320 together form a continuous and axially symmetrical Venturi nozzle flow channel. The combined combustion nozzle 310 includes a gas inlet pipe 311 and an oxygen inlet pipe 312. The gas inlet pipe 311 is sleeved outside the oxygen inlet pipe 312. The inner wall of the gas inlet pipe 311 and the outer wall of the oxygen inlet pipe 312 together form a gas passage. An oxygen interface 302 is provided at the end of the oxygen inlet pipe 312, and a gas interface 301 is provided at the end of the gas inlet pipe 311. After entering the bend, the material distribution is relatively uniform. The main function of the throat 320 is to control the contact between the material and the flame, ensuring the full combustion of the material and the flame. A combined combustion nozzle 310 is arranged in the center of the throat 320. The pressure of the gas inlet pipe 311 in the center of the nozzle is about 4 bar. The nozzle outlet is designed as a Venturi nozzle. The surrounding oxygen is at a pressure of 2.5~3 bar with a purity of over 93%. At this time, the gas velocity generated by the nozzle can reach over 300 m / s. After the material is burned by the flame, it will be immediately accelerated and pushed out by the airflow. The high-speed airflow plays a role in rapid transportation, avoiding the material from sticking together in a high-temperature environment.

[0050] An annular cooling water baffle 322 is provided outside the throat 320, which completely covers the flame spray area of ​​the combined combustion gun 310. The cooling water baffle 322 has a cooling water inlet and an outlet at each end, respectively. The cooling medium flows in from one side of the spray area and flows out from the other side, forming a complete circulating cooling circuit. This design ensures that the throat 320 is adequately cooled, and this component can be made of high-temperature resistant ceramic tubing to meet operational requirements.

[0051] A discharge pipe is connected to the outlet of the throat 320, and a makeup air filter box 330 is installed on this pipe. When the highly spherical powder generated by the flame combustion passes through with the airflow, it is rapidly cooled by injecting a large amount of cold air to prevent re-adhesion after high-temperature melting; the built-in filtration system of the makeup air filter box 330 can effectively remove suspended particles in the air to allow clean air to enter. To precisely adjust the makeup air volume, a makeup air proportional valve 331 is specially configured at the bottom of the equipment, which can precisely control the air intake volume according to process requirements.

[0052] Furthermore, the spheroidizing system 10 for preparing high-sphericity powder by flame method also includes a cyclone collector and a bag filter 500. The discharge pipe is directly connected to the cyclone collector, which has a coarse powder inlet at the bottom and a gas outlet at the top. The gas outlet is connected to the inlet of the bag filter 500 via a pipe. The bag filter 500 has a fine powder inlet at the bottom and its top outlet is connected to a centrifugal fan 600, which has an exhaust port 601. This system achieves effective classification and collection of spheroidized powder through the synergistic action of the cyclone separator 400 and the bag filter. Structurally, both the cyclone collector and the bag filter are equipped with air valves 410 at the bottom to ensure system sealing and operational stability. Simultaneously, the centrifugal fan 600 provides the necessary negative pressure suction, satisfying both the separation requirements of the cyclone collector and the efficient operation of the bag filter. This dual collection mechanism not only improves powder collection efficiency but also ensures accurate classification of powders of different particle sizes.

[0053] The working process of the spheroidizing system 10 used for flame preparation of high sphericity powder is as follows:

[0054] Material is fed from raw material silo 110 to feeding hopper 210 of material dispersion device 200 via feeding impeller 120. Gas is injected into the material conveying air jet port 201 at the bottom of feeding hopper 210, which conveys the material through material conveying channel 211 to dispersing chamber 203 inside dispersing mechanism 220. Gas is introduced through gas collecting ring 230 from all sides of dispersing chamber 203. In dispersing chamber 203, gas fully crushes and disperses the material. The dispersed material enters flame combustion device 300 through pipeline. Here, the material is in a uniform atomized state, and the flow rate can be controlled to be about 8~15m / s. The material enters the curved pipe and is further ejected from the Venturi nozzle structure between the throat 320 and the combined combustion nozzle. The nozzle simultaneously supplies fuel gas and oxygen; the central fuel gas pressure is approximately 4 bar, and the peripheral oxygen pressure is 2.5-3 bar, with a purity of over 93%. The gas velocity ejected from the Venturi nozzle structure can reach approximately 180 m / s. After combustion, the material is immediately accelerated and propelled by the airflow. This high-speed airflow provides rapid transport, preventing the material from sticking together at high temperatures. The material is then cooled by a large amount of cold air introduced through the air intake of the make-up air filter box 330. After rapid cooling, the material is collected in stages by the subsequent cyclone collector and bag filter 500. The resulting highly spherical, narrowly distributed powder... Figure 5 As shown.

[0055] In summary, the technical solution proposed in this invention achieves efficient online instantaneous deagglomeration of powder agglomerates in the conveying airflow by applying a specific structured airflow shear field in the instantaneous stage or within an extremely short conveying path before the powder enters the high-temperature zone of the flame, ensuring that the powder remains in a single-particle dispersed state until it enters the high-speed jet flame zone. This solution, combined with the optimized design of the Venturi nozzle, significantly improves powder dispersion performance, specifically manifested in the following technical advantages: 1. Excellent dispersion performance: It can efficiently and stably achieve online instantaneous deagglomeration of powder agglomerates in the conveying airflow, ensuring that the material enters the high-temperature zone of the flame in a highly discrete single-particle state; 2. Significantly improved core product indicators: The sphericity rate is close to 100%, effectively suppressing the formation of incomplete global agglomerates resembling "grape bunches," significantly improving sphericity, making individual particles closer to the ideal spherical shape, with a narrow and precisely controllable particle size distribution, effectively eliminating abnormally large particles caused by particle adhesion and merging, and obtaining a particle size distribution (D5) with high concentration and meeting the target requirements. 0. Precise and controllable, with a significantly reduced Span value); 3. Outstanding process advantages: Significantly improved production efficiency and product yield: greatly reduces defective products (agglomerates, large particles), increases the yield of fine powder that meets specifications, and reduces unit production costs; Significantly improved batch consistency: stable dispersion effect ensures stable product quality, and significantly improves batch-to-batch consistency; Wide material applicability: suitable for flame spheroidization processing of various materials (including metals, ceramics, inorganic non-metals, etc.) and particle size ranges (especially micro-fine powders that are difficult to process by traditional processes); Improved environmental friendliness of the process: the use of physical dispersion can reduce or avoid the use of chemical dispersants, effectively reducing the risk of impurity introduction.

[0056] In the manufacturing process of semiconductor filler materials, according to experimental data, when the particle size D50 of the raw material is in the range of 1~10μm, the product manufactured by the above scheme can effectively control the BET between 0.5~8cm² / g. The key factor affecting the specific surface ratio is the proportion of vaporized SiO2 "fluff" attached to the surface of the powder particles. By controlling the internal ambient temperature of the control device and combining it with the flow rate of the material, the specific surface ratio can be accurately controlled.

[0057] This technical solution achieves synergistic optimization of powder dispersion and spheroidization processes through innovative airflow shear field design and optimized coordination with Venturi nozzles, providing a reliable technical solution for the preparation of high-performance spherical powder materials.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A spheroidizing system for preparing high-sphericity powders by flame method, characterized in that, It includes a feeding device, a material dispersing device, and a flame combustion device connected in sequence. The material dispersing device is configured to form a multi-stage airflow shear field inside. The flame combustion device includes a combined combustion nozzle and a throat sleeved outside the combined combustion nozzle. The feeding end of the throat is connected to the material outlet of the material dispersing device. The combined combustion nozzle is located at the center of the throat. The throat has an annular protrusion at the position corresponding to the nozzle of the combined combustion nozzle. The annular protrusion and the inner wall of the throat together form a continuous and axially symmetrical Venturi nozzle channel. The material dispersion device includes a feeding funnel, a dispersing mechanism, and a gas collecting ring. A material conveying gas nozzle is located on one side of the bottom of the feeding funnel. On the other side of the bottom of the feeding funnel, opposite the material conveying gas nozzle, a material conveying channel communicating with the dispersing mechanism is provided. The dispersing mechanism has a cylindrical dispersing chamber inside. The gas collecting ring has multiple gas outlet pipes arranged circumferentially around it. These multiple gas outlet pipes are connected to the side wall of the dispersing mechanism and communicate with the dispersing chamber. The central area of ​​the dispersing chamber is connected to the throat pipe via a pipe. A cooling water sump is also provided outside the throat pipe, and the cooling water sump completely covers the flame spray area of ​​the combined combustion gun.

2. The spheroidizing system for preparing high-sphericity powder by flame method according to claim 1, characterized in that, The gas collecting ring is located below the dispersing mechanism, and the top of the central area of ​​the dispersing chamber is connected to the throat tube via a pipe; And / or, the connection points of the plurality of air outlet pipes with the dispersing chamber are located at the same horizontal height of the dispersing chamber and are evenly spaced along the peripheral wall of the dispersing chamber, and the air outlet direction of the plurality of air outlet pipes is at the same angle to the peripheral wall of the dispersing chamber and is 40 to 60 degrees. And / or, the gas collecting ring is also equipped with a pressure monitoring instrument.

3. The spheroidizing system for preparing high-sphericity powder by flame method according to any one of claims 1 to 2, characterized in that, The feeding device includes a raw material bin, and a feeding impeller is provided at the bottom outlet of the raw material bin.

4. The spheroidizing system for preparing high-sphericity powder by flame method according to any one of claims 1 to 2, characterized in that, The combined combustion nozzle includes an oxygen inlet pipe and a gas inlet pipe. The gas inlet pipe is sleeved outside the oxygen inlet pipe. The inner wall of the gas inlet pipe and the outer wall of the oxygen inlet pipe together form a gas passage. An oxygen interface is provided at the end of the oxygen inlet pipe, and a gas interface is provided at the end of the gas inlet pipe.

5. The spheroidizing system for preparing high-sphericity powder by flame method according to any one of claims 1 to 2, characterized in that, It also includes a cyclone collecting device, the inlet of which is connected to the outlet of the flame combustion device. The bottom of the cyclone collecting device is provided with a coarse powder discharge port, and the top of the cyclone collecting device is provided with a gas outlet. A makeup air filter box for makeup air is also provided on the connecting pipe between the cyclone collecting device and the flame combustion device.

6. The spheroidizing system for preparing high-sphericity powder by flame method according to claim 5, characterized in that, It also includes a bag collection device, the gas outlet of which is connected to the inlet of the bag collection device, a fine powder discharge port at the bottom of the bag collection device, and a centrifugal fan connected to the top outlet of the bag collection device.

7. The spheroidizing system for preparing high-sphericity powder by flame method according to any one of claims 1 to 2, characterized in that, The cooling water jacket has a cooling water inlet and a cooling water outlet at each end.

8. A semiconductor filler material, characterized in that, It is prepared from raw materials with a particle size D50 of 1~10μm by a spheroidizing system for preparing high sphericity powder by flame method according to any one of claims 1 to 7, and the specific surface area of ​​the semiconductor filler material is 0.5~8cm² / g.

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