Spheroidizing furnace and silicon dioxide powder production system

Abstract

This invention provides a spheroidizing furnace and a silica powder production system. The spheroidizing furnace includes a furnace body with a gaseous silica inlet at the top and a solid silica outlet on the lower side. A heat exchange jacket is installed on the outer wall of the furnace body, extending from the top of the furnace body at least to the solid silica outlet. The heat exchange jacket is divided into multiple sections, each with a cooling medium inlet and outlet. A main air inlet is located at the furnace body corresponding to the uppermost heat exchange jacket section, and auxiliary gas inlets are located at the furnace body corresponding to each heat exchange jacket section. This structural design allows for precise control of the cooling flow field and airflow (including material) in the spheroidizing furnace, achieving precise control over product particle size and distribution, and improving the quality of the silica powder.

Description

Technical Field

[0001] This utility model relates to the field of silicon dioxide powder preparation technology, and more specifically, to a spheroidizing furnace and a silicon dioxide powder production system. Background Technology

[0002] With the rapid development of the global electronics and information industry and the continuous improvement of technologies such as 5G and AI, higher technical requirements have been placed on electronic products to be thinner and smaller, on chip packaging performance, and on the substrates that support the chips. This, in turn, places higher technical demands on silica, such as higher purity, suitable particle size distribution, low alpha phase content, and greater internal density. Spherical silica, as a key material in large-scale integrated circuit packaging and IC substrate industries, is increasingly widely used in these sectors.

[0003] The spheroidizing furnace is a key piece of equipment in the combustion synthesis method. Silicon powder is burned in the combustion vaporization chamber to generate silica vapor, which then enters the spheroidizing furnace for cooling, changing from a gaseous state to a liquid state, and then from a liquid state to a solid state, forming spherical silica powder. However, existing spheroidizing furnaces cannot precisely control the flow rate of the airflow (including materials) within the furnace body and the heat dissipation, which directly affects the quality and performance of the final product, thereby impacting the reliability and stability of downstream products.

[0004] In view of this, this utility model is proposed. Utility Model Content

[0005] The purpose of this invention is to provide a spheroidizing furnace and a silica powder production system to improve the aforementioned technical problems.

[0006] The embodiments of this utility model can be implemented as follows: In a first aspect, this utility model provides a spheroidizing furnace, which includes a furnace body. A gaseous silica inlet is provided at the top of the furnace body, and a solid silica outlet is provided on the lower side of the furnace body. A heat exchange jacket is provided on the outer wall of the furnace body. The heat exchange jacket extends from the top of the furnace body at least to the solid silica outlet. The heat exchange jacket is divided into multiple sections. Each section of the heat exchange jacket is provided with a jacket cooling medium inlet and a jacket cooling medium outlet. A main gas inlet is provided at the furnace body part corresponding to the uppermost section of the heat exchange jacket, and an auxiliary gas inlet is provided at the furnace body part corresponding to each section of the heat exchange jacket.

[0007] In an optional implementation, the heat exchange jacket is divided into at least three sections.

[0008] In an optional embodiment, each of the auxiliary gas inlets is provided with a first flow regulating device.

[0009] In an optional embodiment, the furnace body is cylindrical in shape and conical at the bottom end, and the heat exchange jacket extends from the top of the furnace body to the end of the cylindrical section of the furnace body.

[0010] In an optional embodiment, the top of the furnace body is an open end, and a jacket cover is provided on the top of the furnace body. The jacket cover is detachably connected to the top of the furnace body to close the top of the furnace body. The jacket cover is provided with a jacket cover cooling medium inlet and a jacket cover cooling medium outlet. The gaseous silica inlet is located in the middle of the jacket cover, and a second flow regulating device is correspondingly provided on the jacket cover cooling medium inlet.

[0011] In an optional embodiment, an air inlet pipe is connected to the bottom end of the furnace body, and a third flow regulating device and a first surfactant injection device are provided on the air inlet pipe.

[0012] Secondly, this utility model provides a silicon dioxide powder production system, which includes a spheroidizing furnace and a combustion vaporization chamber as described in any of the foregoing embodiments, wherein the outlet of the combustion vaporization chamber is connected to the gaseous silicon dioxide inlet of the spheroidizing furnace.

[0013] In an optional embodiment, it further includes an ultrafine classification system, a dust collection system, and a fan system. The ultrafine classification system is connected to the solid silica outlet of the spheroidizing furnace, the gas outlet of the ultrafine classification system is connected to the air inlet of the dust collection system, the air outlet of the dust collection system is connected to the air inlet of the fan system, and the air outlet of the fan system is connected to the main air inlet on the furnace body.

[0014] In an optional embodiment, an air inlet pipe is provided at the bottom of the spheroidizing furnace, and a first surfactant injection device is provided on the air inlet pipe. The air outlet of the blower system is connected to the air inlet pipe.

[0015] In an optional embodiment, a cyclone separation system is further provided between the ultrafine classification system and the spheroidizing furnace. The cyclone separation system is connected to the ultrafine classification system and the spheroidizing furnace through pipelines. A second surfactant injection device is also provided on the pipeline between the spheroidizing furnace and the cyclone separation system.

[0016] The beneficial effects of the spheroidizing furnace and silica powder production system provided in this embodiment of the utility model include: by designing the heat exchange jacket on the furnace body into multiple sections, each section is provided with a jacket cooling medium inlet and a jacket cooling medium outlet, and each section of the furnace body corresponding to the heat exchange jacket is provided with an auxiliary gas inlet, the cooling flow field and airflow (including material) of the spheroidizing furnace can be precisely controlled through the above structural settings, thereby achieving the desired particle size and particle size distribution of the product and improving the product quality of silica powder. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model 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.

[0018] Figure 1 This is a schematic diagram of the structure of the spheroidizing furnace provided in the first embodiment of the present invention; Figure 2 A schematic diagram of the silicon dioxide production system is provided for the second embodiment of this utility model.

[0019] Icons: 1-Homogenization silo; 2-Fluidized silo; 3-Feeder; 4-Powder injector; 5-Combustion vaporization chamber; 6-Spheroidizing furnace; 6.1-Jacket cover; 6Cb1-Jacket cover cooling medium outlet; 6Jb1-Jacket cover cooling medium inlet; 6J1-Gaseous silica inlet; 6J2-Main air inlet; 6C1-Solid silica outlet; 6.2T1-Heat exchange stage 1; 6.2T2-Heat exchange stage 2; 6.2T3-Heat exchange stage 3; 6Jb2-First jacket cooling medium inlet; 6Cb2-First... Jacket cooling medium outlet; 6Jb3 - Second jacket cooling medium inlet; 6Cb3 - Second jacket cooling medium outlet; 6Jb4 - Third jacket cooling medium inlet; 6Cb4 - Third jacket cooling medium outlet; 6Ja1 - First auxiliary gas inlet; 6Ja2 - Second auxiliary gas inlet; 6Ja3 - Third auxiliary gas inlet; 7 - Cyclone separation system; 8 - Ultrafine classification system; 9 - Dust collection system; 10 - Fan system; 11 - Third material collection tank; 12 - Second material collection tank; 13 - First material collection tank. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present 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 present invention without inventive effort are within the scope of protection of the present invention.

[0022] 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.

[0023] In the description of this utility model, 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 utility model product is usually placed during use, they are only for the convenience of describing this utility model 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 utility model.

[0024] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0025] It should be noted that, where there is no conflict, the features in the embodiments of this utility model can be combined with each other.

[0026] The following detailed description, through embodiments and in conjunction with the accompanying drawings, details the overall structure, working principle, and technical effects of a spheroidizing furnace and silica powder production system provided by this utility model.

[0027] First Embodiment See Figure 1 This utility model provides a spheroidizing furnace 6, which includes a furnace body. A gaseous silica inlet 6J1 is provided at the top of the furnace body. That is, the silica vapor generated after the silicon powder is burned can enter the furnace body of the spheroidizing furnace 6 from the gaseous silica inlet 6J1 at the top under the action of the gas. A solid silica outlet 6C1 is provided on the lower side of the furnace body. The silica vapor enters the spheroidizing furnace 6 for cooling and temperature reduction, changing from gaseous to liquid, and then from liquid to solid to form spherical silica powder. The negative pressure gas generated by the induced draft fan is drawn out from the solid silica outlet 6C1.

[0028] In this embodiment, the furnace body is cylindrical with a conical bottom. A heat exchange jacket is provided on the outer wall of the furnace body, extending from the top of the furnace body at least to the solid silica outlet 6C1. Exemplarily, the heat exchange jacket extends from the top of the furnace body to the end of the cylindrical section. The cylindrical main structure facilitates uniform cooling and reaction of the internal materials, while the conical bottom facilitates gas entry and material discharge, reducing material residue. The extension range of the heat exchange jacket, combined with this shape, fully utilizes cooling and airflow regulation in the main material reaction area, namely the cylindrical section, improving production efficiency and product quality.

[0029] Furthermore, in this embodiment, the heat exchange jacket is divided into multiple sections, each with a cooling medium inlet and an outlet. This allows the cooling medium to enter and exit in segments, enabling more precise temperature control of different areas. The uppermost heat exchange jacket section corresponds to a main air inlet 6J2 in the furnace body, providing the main airflow for the reaction inside the furnace. Each heat exchange jacket section corresponds to an auxiliary gas inlet in the furnace body, which helps to adjust the airflow distribution inside the furnace. The overall structure creates the foundation for subsequent precise control.

[0030] Specifically, in this embodiment, the heat exchange jacket is divided into at least three sections, for example, it can be divided into three sections. More sections mean a more precise degree of temperature and airflow control. Compared with heat exchange jackets that are not segmented or have few segments, a design with three or more sections can more accurately adjust the cooling effect for different height areas of the furnace body, adapting to the differentiated temperature and airflow requirements of different reaction stages, thereby ensuring the stability of product quality. For example, the heat exchange jacket can be divided into a first heat exchange section 2T1, a second heat exchange section 2T2, and a third heat exchange section 2T3. Among them, the first heat exchange section 2T1 is shorter than the second heat exchange section 2T2 and the third heat exchange section 2T3 along the furnace body axis. The actual number of sections and the length of each section of the heat exchange jacket are set according to the actual situation of the spheroidizing furnace 6. The first heat exchange stage 2T1 is equipped with a first jacket cooling medium inlet 6Jb2 and a first jacket cooling medium outlet 6Cb2, and the furnace body corresponding to the first heat exchange stage 2T1 is also equipped with a first auxiliary gas inlet 6Ja1; the second heat exchange stage 2T2 is equipped with a second jacket cooling medium inlet 6Jb3 and a second jacket cooling medium outlet 6Cb3, and the furnace body corresponding to the second heat exchange stage 2T2 is also equipped with a second auxiliary gas inlet 6Ja2; the third heat exchange stage 2T3 is equipped with a third jacket cooling medium inlet 6Jb4 and a third jacket cooling medium outlet 6Cb4, and the furnace body corresponding to the third heat exchange stage 2T3 is also equipped with a third auxiliary gas inlet 6Ja3.

[0031] Furthermore, each of the aforementioned auxiliary gas inlets is equipped with a first flow rate regulating device (not shown in the figure). During the spheroidizing reaction, the required auxiliary gas flow rate varies at different stages and in different regions. With the first flow rate regulating device, operators can precisely control the gas intake of each auxiliary gas inlet according to actual production needs, avoiding deviations in product particle size and distribution due to unstable gas intake, and further ensuring the quality uniformity of the silica powder product.

[0032] Furthermore, the top of the furnace body is an open end, and a jacketed cover 6.1 is installed on the top of the furnace body. The jacketed cover 6.1 is detachably connected to the top of the furnace body to seal the top of the furnace body. The jacketed cover 6.1 is provided with a jacketed cover cooling medium inlet 6Jb1 and a jacketed cover cooling medium outlet 6Cb1. A gaseous silica inlet 6J1 is located in the middle of the jacketed cover 6.1. A second flow regulating device (not shown in the figure) is correspondingly provided for the jacketed cover cooling medium inlet 6Jb1. The detachable cover facilitates maintenance and cleaning, and the independent regulation of the cooling medium can precisely control the temperature of the top area of ​​the furnace body, that is, the raw material inlet, to prevent the raw material from reacting too early or agglomerating, and to ensure the smooth progress of subsequent reactions.

[0033] It should be noted that both the first and second flow regulating devices can be commonly used flow control valves.

[0034] An air inlet pipe (not shown) can be connected to the bottom end of the furnace body. The air inlet pipe is equipped with a third flow regulating device (not shown) and a first surfactant injection device (not shown). The conical structure of the furnace bottom also facilitates the dispersion of the surfactant loaded in the incoming gas. The air inlet pipe provides a channel for introducing gas from the bottom. The third flow regulating device precisely controls the air intake, while the addition of the first surfactant injection device is crucial. Surfactants can alter the surface properties of materials, assisting in the regulation of particle formation during spheroidization. Combined with precise airflow, this helps obtain silica powder with ideal particle size and distribution, improving the flowability and dispersibility of the silica powder. For example, the surfactant can be silicone oil, silane, etc. It should be noted that the third flow regulating device can be a commonly used flow control valve.

[0035] Second Embodiment See Figure 2 This embodiment provides a silica powder production system, which includes a combustion vaporization chamber 5 and a spheroidizing furnace 6 as described in the first embodiment. The outlet of the combustion vaporization chamber 5 is connected to the gaseous silica inlet 6J1 of the spheroidizing furnace 6. The combustion vaporization chamber 5 is responsible for vaporizing the silica raw material, converting it into a gaseous state, and then conveying it to the spheroidizing furnace 6 for spheroidizing reaction. The two work closely together to form a key front-end link of the production system, providing a suitable raw material form for the subsequent production of high-quality silica powder.

[0036] Specifically, in this embodiment, the silicon dioxide powder production system further includes a homogenization storage silo 1, a fluidization silo 2, a feeder 3, and a powder sprayer 4 connected in sequence by pipelines. The powder sprayer 4 is connected to the combustion vaporization chamber 5. Silicon powder (including but not limited to one or more of metallic silicon powder, wafer slicing polishing silicon powder, and seed crystal cutting silicon powder) is fed into the homogenization storage silo 1 for homogenization. The homogenized raw material enters the fluidization silo 2 at a set feeding rate, and then enters the combustion vaporization chamber 5 for combustion vaporization via the feeder 3 and the powder sprayer 4.

[0037] As shown in the first embodiment, an air inlet pipe is provided at the bottom of the spheroidizing furnace 6, and a first surfactant injection device is provided on the air inlet pipe, the specific location of which is as follows: Figure 2 At point SJ1. The surfactant sprayed from the bottom can fully mix and react with the silica powder, improving the flowability and dispersibility of the silica powder.

[0038] Furthermore, the silica powder production system also includes a cyclone separation system 7 and an ultrafine classification system 8. The solid silica outlet of the spheroidizing furnace 6 is connected to the cyclone separation system 7 via a pipeline. The cyclone separator can separate agglomerates or large particles, while the fine powder enters the ultrafine classification system 8 with the airflow, and the coarse powder is used as raw material. It should be noted that a first material collection bucket 13 is installed at the bottom of the cyclone separation system 7 to collect agglomerated or large-particle silica powder. Because silica produced by the deflagration method has poor dispersibility and flowability after cooling, ordinary classification processes struggle to achieve precise top-cut classification of cold materials. However, in this process, the material is hot and has undergone surface treatment, resulting in good dispersibility and flowability, making it easy to achieve precise top-cut classification through the ultrafine classification system 8. Moreover, compared to traditional offline classification, this process is online classification, eliminating the need for a feeding system or a separate collection system, thus saving on production line investment and space. A second material collection bucket 12 is installed at the bottom of the ultrafine classification system 8 to collect coarser silica powder that does not meet the target particle size.

[0039] Furthermore, a second surfactant injection device (not shown in the figure) is also installed on the pipe connecting the cyclone separation system 7 and the spheroidizing furnace 6. The specific location is as follows: Figure 2 At point SJ2 in the process, a second surfactant injection device is added. This device can readjust the surface properties of the particles during the material circulation process, further improving the dispersibility and flowability of the final silica powder, reducing or even completely removing the hydroxyl groups on the silica surface, and grafting new functional groups. This, in turn, significantly improves product quality through precise classification.

[0040] See you again Figure 2The silica powder production system also includes a dust collection system 9. The gas outlet of the ultrafine classification system 8 is connected to the air inlet of the dust collection system 9, and the air outlet of the dust collection system 9 is connected to the air inlet of the fan system 10. The air outlet of the fan system 10 is connected to the main air inlet 6J2 on the furnace body and the air inlet pipe at the bottom. That is, the airflow containing silica powder of the target particle size after being classified by the ultrafine classification system 8 is filtered by the dust collection system 9, and the finished silica powder is collected through the third material collection bucket 11 at the bottom of the dust collection system 9. After removing the silica powder, the gas loaded with silica powder enters the fan system 10. The fan system 10 can exhaust part of the gas as needed. The fan system 10 circulates the gas to the spheroidizing furnace 6 for reuse. Part of the gas can be introduced into the air inlet pipe at the bottom of the spheroidizing furnace 6 as the carrier gas for surfactant, and another part of the gas can be introduced into the furnace body through the main air inlet 6J2 on the furnace body.

[0041] In summary, the spheroidizing furnace 6 and the silica powder production system achieve precise control over the cooling flow field, airflow, and material surface properties, effectively improving the product quality of silica powder. Furthermore, the main gas is recycled, reducing production costs.

[0042] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model.

Claims

1. A spheroidizing furnace characterized by comprising: It includes a furnace body, with a gaseous silica inlet at the top and a solid silica outlet on the lower side of the furnace body. A heat exchange jacket is provided on the outer wall of the furnace body, extending from the top of the furnace body at least to the solid silica outlet. The heat exchange jacket is divided into multiple sections, each of which has a jacket cooling medium inlet and a jacket cooling medium outlet. The uppermost section of the heat exchange jacket has a main air inlet at the corresponding part of the furnace body, and each section of the heat exchange jacket has an auxiliary gas inlet at the corresponding part of the furnace body.

2. A spheroidizing furnace according to claim 1, characterized in that The heat exchange jacket is divided into at least three sections.

3. A spheroidizing furnace according to claim 1, characterized in that Each of the main air inlet and each of the auxiliary gas inlets is equipped with a first flow regulating device.

4. A spheroidizing furnace according to claim 1, characterized in that The furnace body is cylindrical in shape and conical at the bottom end. The heat exchange jacket extends from the top of the furnace body to the end of the cylindrical section of the furnace body.

5. A spheroidizing furnace as claimed in claim 1, characterized in that The top of the furnace body is an open end, and a jacketed cover is provided on the top of the furnace body. The jacketed cover is detachably connected to the top of the furnace body to close the top of the furnace body. The jacketed cover is provided with a jacketed cover cooling medium inlet and a jacketed cover cooling medium outlet. The gaseous silica inlet is located in the middle of the jacketed cover, and a second flow regulating device is provided corresponding to the jacketed cover cooling medium inlet.

6. A spheroidizing furnace according to any one of claims 1 to 5, characterized in that The bottom end of the furnace body is connected to an air inlet pipe, and the air inlet pipe is equipped with a third flow regulating device and a first surfactant injection device.

7. A system for producing a silica powder, characterized by comprising: It includes the spheroidizing furnace and the combustion vaporization chamber as described in any one of claims 1 to 6, wherein the outlet of the combustion vaporization chamber is connected to the gaseous silica inlet of the spheroidizing furnace.

8. The silica powder production system according to claim 7, characterized by, It also includes an ultrafine classification system, a dust collection system, and a fan system. The ultrafine classification system is connected to the solid silica outlet of the spheroidizing furnace. The gas outlet of the ultrafine classification system is connected to the air inlet of the dust collection system. The air outlet of the dust collection system is connected to the air inlet of the fan system. The air outlet of the fan system is connected to the main air inlet on the furnace body.

9. The silica powder production system according to claim 8, characterized by, The bottom of the spheroidizing furnace is provided with an air inlet pipe, and a first surfactant injection device is provided on the air inlet pipe. The air outlet of the blower system is connected to the air inlet pipe.

10. The silica powder production system according to claim 9, characterized by, A cyclone separation system is also provided between the ultrafine classification system and the spheroidizing furnace. The cyclone separation system is connected to the ultrafine classification system and the spheroidizing furnace through pipelines. A second surfactant injection device is also provided on the pipeline between the spheroidizing furnace and the cyclone separation system.

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