Flow field improvement device
By designing a flow field improvement device, the problem of uneven gas mixing in the chemical vapor deposition furnace cavity was solved, achieving uniform gas distribution in the reaction area and improving deposition efficiency and product consistency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HUNAN BOOM NEW MATERIALS
- Filing Date
- 2025-06-25
- Publication Date
- 2026-07-07
AI Technical Summary
During chemical vapor deposition, uneven gas mixing and flow field distribution within the furnace cavity lead to a gradient distribution of deposition rates, affecting the consistency and reliability of product performance.
A flow field improvement device is adopted, including an inner cylinder, a middle cylinder and an outer cylinder, a gas collecting funnel and a guide cone, to form a gradually changing gas gathering channel and a uniform mixing area, ensuring the uniform distribution of gas in the reaction area.
It significantly improves the uniformity of the flow field inside the furnace, reduces the difference in interface layer thickness, and improves deposition efficiency, making it suitable for the preparation of uniform coatings on workpieces with complex shapes.
Smart Images
Figure CN224467910U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of flow guiding devices, and more specifically, it relates to a flow field improvement device. Background Technology
[0002] In the field of material surface interface layer preparation, chemical vapor deposition (CVD) technology has become an important means of surface modification for various materials such as ceramics and metals due to its significant advantages, including high deposition efficiency, good coating quality, low preparation temperature, simple equipment, and applicability to complex components. This technology generates solid deposits on solid surfaces through gas-phase chemical reactions, enabling the controllable growth of high-precision coatings.
[0003] In practical applications, especially in deposition processes involving multiple gas components, traditional methods typically employ multiple independent inlet pipes to separately introduce the reactant gas and carrier gas into the mixing chamber. Due to differences in flow velocity, pressure, and direction at each gas inlet, it is difficult to establish a stable flow field distribution within the mixing chamber. When the mixed gas enters the vapor deposition furnace, the superposition of turbulence and boundary layer effects further exacerbates the flow field inhomogeneity, manifesting as significant differences in gas velocity, concentration, and residence time in different regions of the deposition object. This non-uniform gas environment results in a spatially gradient distribution of deposition rates, which not only reduces the overall density and bonding strength of the deposition interface but also causes coating thickness fluctuations exceeding process tolerances, severely impacting product performance consistency and reliability. Utility Model Content
[0004] The purpose of this application is to provide a flow field improvement device to solve the technical problems of uneven gas mixing and flow field distribution in the furnace cavity in the prior art.
[0005] To achieve the above objectives, the technical solution adopted in this application is as follows:
[0006] A flow field improvement device is provided, comprising:
[0007] An inner cylinder, a middle cylinder, and an outer cylinder extending vertically; the middle cylinder is fitted around the outside of the inner cylinder and spaced apart from the inner cylinder; the outer cylinder is fitted around the outside of the middle cylinder and spaced apart from the middle cylinder.
[0008] The gas collecting funnel has its small end connected to the top of the middle cylinder and its large end connected to the inner wall of the outer cylinder.
[0009] A guide cone is located inside the gas collecting funnel and covers the top of the inner cylinder;
[0010] A base plate supports the bottom of the inner cylinder and the middle cylinder; the base plate is provided with ventilation holes;
[0011] The gas collecting funnel and the guide cone enclose a gas mixing zone; the inner cylinder and the middle cylinder enclose a reaction zone; the gas mixing zone, the reaction zone, and the vent are connected in sequence.
[0012] As a further improvement to the above technical solution:
[0013] Optionally, the base of the guide cone is placed over the opening at the top of the inner cylinder, and the diameter of the guide cone gradually decreases from the base to the top.
[0014] Optionally, the apex angle of the guide cone ranges from 60° to 90°.
[0015] Optionally, the height of the guide cone is in the range of 150mm-250mm.
[0016] Optionally, the gas collecting funnel includes a conical section and a flat section, the larger end of the conical section is connected to the inner wall of the outer cylinder, the smaller end of the conical section is connected to the flat section, and the flat section is supported on the top of the middle cylinder.
[0017] Optionally, the flat plate has an opening, the diameter of which is smaller than the diameter of the middle cylinder and larger than the diameter of the inner cylinder.
[0018] Optionally, the height of the outer cylinder is greater than the sum of the heights of the gas collecting funnel and the middle cylinder, and also greater than the sum of the heights of the inner cylinder and the guide cone.
[0019] Optionally, the inner cylinder and the middle cylinder have the same height.
[0020] Optionally, there may be multiple inner cylinders, middle cylinders, and outer cylinders, and each inner cylinder, middle cylinder, or outer cylinder may be stacked sequentially in the vertical direction.
[0021] Optionally, the height of a single outer cylinder is greater than the height of a single inner cylinder or a single middle cylinder.
[0022] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0023] The flow field improvement device provided in this application includes an inner cylinder, a middle cylinder, and an outer cylinder extending vertically. The middle cylinder is fitted outside the inner cylinder and spaced apart from it. The outer cylinder is fitted outside the middle cylinder and spaced apart from it. The small end of a gas collecting funnel is connected to the top of the middle cylinder, and the large end of the gas collecting funnel is connected to the inner wall of the outer cylinder, forming a gradually changing gas converging channel. A guide cone is located inside the gas collecting funnel and covers the top of the inner cylinder. A base plate supports the bottom of the inner and middle cylinders and has vent holes for gas flow and discharge. Multiple gas inlets first enter the gas mixing area formed by the gas collecting funnel and the guide cone. In this area, gases of different components are fully mixed through a gradually narrowing flow channel. The mixed gas is guided by the guide cone and uniformly enters the reaction area between the inner and middle cylinders, avoiding turbulence caused by sudden changes in flow velocity or turbulent flow direction, thereby ensuring the uniformity of gas distribution in the reaction area. The gas mixing zone, reaction zone, and vent holes in the bottom plate are connected in sequence to form a continuous and stable gas flow path.
[0024] This device effectively controls the diffusion and flow of gas through a centralized mixing and re-diffusion gas flow method, making the gas concentration and flow rate more uniform at various locations within the reaction zone, and significantly improving the uniformity of the flow field inside the furnace. This structural design can reduce the difference in interface layer thickness during the deposition process, improve deposition efficiency, and is suitable for the preparation of uniform coatings on workpieces with complex shapes. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0026] Figure 1 This is a cross-sectional structural schematic diagram of the flow field improvement device of this application;
[0027] Figure 2 This is a three-dimensional structural schematic diagram of the flow field improvement device of this application.
[0028] The following are the labeling elements in the figure:
[0029] 1. Inner cylinder; 2. Middle cylinder; 3. Outer cylinder; 4. Gas collecting funnel; 41. Conical section; 42. Bottom plate section; 5. Guide cone; 6. Bottom plate; 61. Through hole and vent hole. Detailed Implementation
[0030] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.
[0031] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on the other component. When a component is referred to as "connected to" or "sleeved on" another component, it can be directly connected to or indirectly connected to the other component.
[0032] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application 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. Therefore, they should not be construed as limitations on this application.
[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0034] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of protection of this invention.
[0035] To address the technical problems of uneven gas mixing and unstable flow field distribution within the chemical vapor deposition furnace cavity, such as... Figure 1 and Figure 2 As shown, this application provides a flow field improvement device, which includes an inner cylinder 1, a middle cylinder 2 and an outer cylinder 3 extending in a vertical direction; the middle cylinder 2 is sleeved on the outside of the inner cylinder 1 and spaced apart from the inner cylinder 1; the outer cylinder 3 is sleeved on the outside of the middle cylinder 2 and spaced apart from the middle cylinder 2.
[0036] The small end of the gas collecting funnel 4 is connected to the top of the middle cylinder 2, and the large end of the gas collecting funnel 4 is connected to the inner wall of the outer cylinder 3, forming a gradual gas gathering channel. The guide cone 5 is located inside the gas collecting funnel 4 and covers the top of the inner cylinder 1; the bottom plate 6 is supported at the bottom of the inner cylinder 1 and the middle cylinder 2, and the bottom plate 6 is provided with vent holes 61 for gas flow and discharge.
[0037] The multi-channel air intake first enters the gas mixing zone formed by the gas collecting funnel 4 and the guide cone 5. Within this zone, gases of different components are thoroughly mixed through a gradually narrowing flow channel. The mixed gas, guided by the guide cone 5, enters the reaction zone between the inner cylinder 1 and the middle cylinder 2 uniformly, avoiding turbulence caused by sudden changes in flow velocity or disordered flow direction, thus ensuring consistent gas distribution within the reaction zone. The gas mixing zone, the reaction zone, and the vent holes 61 of the bottom plate 6 are sequentially connected, forming a continuous and stable gas flow path.
[0038] This device effectively controls the diffusion and flow of gas through a centralized mixing and re-diffusion gas flow method, making the gas concentration and flow rate more uniform at various locations within the reaction zone, and significantly improving the uniformity of the flow field inside the furnace. This structural design can reduce the difference in interface layer thickness during the deposition process, improve deposition efficiency, and is suitable for the preparation of uniform coatings on workpieces with complex shapes.
[0039] In one embodiment of this application, the base of the guide cone 5 covers the top opening of the inner cylinder 1 to ensure the integrity of the gas flow path. The guide cone 5 adopts a conical structure design, with its base diameter matching the diameter of the inner cylinder 1's opening, and gradually narrowing upwards along the axial direction to form a tapered guide surface. This conical structure can guide the mixed gas to diffuse evenly in all directions along the conical surface of the guide cone 5, avoiding local turbulence or backflow at the inlet of the middle cylinder 2. The guide cone 5 is used to ensure that the mixed gas can be evenly distributed to the annular reaction area between the inner cylinder 1 and the middle cylinder 2. This structure effectively reduces gas flow resistance and improves the uniformity of gas distribution, providing a stable flow field environment for the subsequent deposition process.
[0040] In one embodiment of this application, the apex angle of the guide cone 5 is in the range of 60°-90°. This angle range is set based on a comprehensive consideration of gas flow characteristics and deposition process requirements: when the apex angle is less than 60°, the cone surface of the guide cone 5 is too gentle, which may lead to a decrease in gas velocity and an increase in flow resistance; while when the apex angle exceeds 90°, the steepness of the cone surface increases, easily causing gas flow separation and resulting in localized turbulence. By controlling the apex angle of the guide cone 5 within the range of 60°-90°, the mixed gas can be uniformly diffused along the cone surface to the reaction area while ensuring smooth gas flow. This angle range satisfies both the dynamic requirements of gas flow and ensures the stability of the flow field during deposition, thereby effectively improving the uniformity of the interface layer deposition.
[0041] In one embodiment of this application, the height of the guide cone 5 ranges from 150mm to 250mm. This size range is determined based on gas flow characteristics and the actual requirements of the deposition process: when the height is below 150mm, the guiding effect of the guide cone 5 is insufficient, potentially leading to inadequate gas mixing; when the height exceeds 250mm, although the guiding effect is enhanced, it increases the equipment size and may generate unnecessary flow resistance. By controlling the height of the guide cone 5 within the range of 150mm-250mm, it ensures that the gas is fully mixed before entering the reaction zone while maintaining reasonable equipment size and gas flow efficiency. This height range helps optimize the gas flow path, ensuring a uniform distribution of the flow field within the reaction zone, thereby improving the stability and consistency of the deposition process.
[0042] In one embodiment of this application, the gas collecting funnel 4 includes a conical section 41 and a bottom plate section 42. The conical section 41 has a tapered conical structure, with its large end abutting against the inner wall of the outer cylinder 3 and its small end connected to the bottom plate section 42. The bottom plate section 42 is horizontally positioned and supported on the top end face of the middle cylinder 2, forming a stable support structure. This structure enables the gas collecting funnel 4 to effectively collect and guide multiple streams of gas into the gas mixing area, while ensuring a stable and reliable connection with the middle cylinder 2 and the outer cylinder 3. The conical structure of the conical section 41 facilitates gas convergence and premixing, while the bottom plate section 42 provides a transition platform for gas flow to the reaction area, together forming an efficient gas guiding channel.
[0043] In one embodiment of this application, the bottom plate portion 42 has a through hole with an opening 61. The diameter of the through hole 61 is smaller than the diameter of the middle cylinder 2 and larger than the diameter of the inner cylinder 1. This dimensional relationship ensures that the gas can smoothly transition from the gas mixing area to the annular reaction area between the inner cylinder 1 and the middle cylinder 2, which avoids abrupt changes in the gas flow cross section and maintains an appropriate gas flow rate, thereby ensuring the uniformity of gas distribution in the reaction area.
[0044] In one embodiment of this application, the height of the outer cylinder 3 is greater than the sum of the heights of the gas collecting funnel 4 and the middle cylinder 2, and also exceeds the sum of the heights of the inner cylinder 1 and the guide cone 5. This height relationship ensures that the outer cylinder 3 can fully accommodate key components such as the gas collecting funnel 4, the middle cylinder 2, the inner cylinder 1, and the guide cone 5, forming a complete closed gas flow channel. The height of the outer cylinder 3 provides sufficient installation space for each internal component while maintaining the continuity of the gas flow path. The mixed gas can complete the entire process from gas intake, mixing to reaction inside the outer cylinder 3, avoiding gas leakage or external interference, thereby ensuring the stability and controllability of the deposition process.
[0045] In one embodiment of this application, the inner cylinder 1 and the middle cylinder 2 are at the same height, so that the top openings of the inner cylinder 1 and the middle cylinder 2 can cooperate with the gas collecting funnel 4 and the guide cone 5 to ensure a smooth transition of gas from the mixing area to the reaction area and avoid uneven gas flow caused by height differences.
[0046] In one embodiment of this application, the inner cylinder 1, middle cylinder 2, and outer cylinder 3 can be modularly combined, with the number of any one or more cylinders adjustable according to actual needs. Multiple cylinders of the same type are stacked vertically to form an expandable composite flow channel structure. The end connections between the cylinders are achieved through mechanical docking, including but not limited to slotted joints and mortise and tenon joints, ensuring stable coaxiality and airtightness of the stacked cylinder assembly. This modular design allows for flexible adjustment of the volume and height of the reaction zone according to actual process requirements, while also facilitating equipment maintenance and component replacement. The stacking and combination of multiple cylinders maintains the gas flow characteristics of a single-layer structure while expanding the processing capacity of the device, making it suitable for deposition processes of different scales.
[0047] In one embodiment of this application, the height of a single outer cylinder 3 is greater than the height of a single inner cylinder 1 or a single middle cylinder 2. This height difference allows the outer cylinder 3 to fully accommodate the inner cylinder 1 and the middle cylinder 2, and creates additional space at its top for installing the gas collecting funnel 4 and the guide cone 5.
[0048] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A flow field improvement device, characterized in that, include: An inner cylinder (1), a middle cylinder (2), and an outer cylinder (3) extending vertically; the middle cylinder (2) is fitted around the outer side of the inner cylinder (1) and spaced apart from the inner cylinder (1); the outer cylinder (3) is fitted around the outer side of the middle cylinder (2) and spaced apart from the middle cylinder (2); The gas collecting funnel (4) has its small end connected to the top of the middle cylinder (2) and its large end connected to the inner wall of the outer cylinder (3); The guide cone (5) is located inside the gas collecting funnel (4) and covers the top of the inner cylinder (1); The bottom plate (6) is supported at the bottom of the inner cylinder (1) and the middle cylinder (2); the bottom plate (6) is provided with ventilation holes (61). The gas collecting funnel (4) and the guide cone (5) enclose a gas mixing area; the inner cylinder (1) and the middle cylinder (2) enclose a reaction area; the gas mixing area, the reaction area and the vent (61) are connected in sequence.
2. The flow field improvement device as described in claim 1, characterized in that, The base of the guide cone (5) is placed on the top opening of the inner cylinder (1), and the diameter of the guide cone (5) gradually decreases from the bottom to the top.
3. The flow field improvement device as described in claim 2, characterized in that, The apex angle of the guide cone (5) ranges from 60° to 90°.
4. The flow field improvement device as described in claim 2, characterized in that, The height range of the guide cone (5) is 150mm-250mm.
5. The flow field improvement device as described in claim 1, characterized in that, The gas collecting funnel (4) includes a conical section (41) and a flat section (42). The large end of the conical section (41) is connected to the inner wall of the outer cylinder (3), and the small end of the conical section (41) is connected to the flat section (42). The flat section (42) is supported on the top of the middle cylinder (2).
6. The flow field improvement device as described in claim 5, characterized in that, The flat plate (42) has an opening with a diameter smaller than that of the middle cylinder (2) and larger than that of the inner cylinder (1).
7. The flow field improvement device according to any one of claims 1 to 6, characterized in that, The height of the outer cylinder (3) is greater than the sum of the heights of the gas collecting funnel (4) and the middle cylinder (2), and is also greater than the sum of the heights of the inner cylinder (1) and the guide cone (5).
8. The flow field improvement device according to any one of claims 1 to 6, characterized in that, The inner cylinder (1) and the middle cylinder (2) have the same height.
9. The flow field improvement device according to any one of claims 1 to 6, characterized in that, The number of any one or more of the inner cylinder (1), middle cylinder (2) and outer cylinder (3) is multiple, and each of the inner cylinder (1) or middle cylinder (2) or outer cylinder (3) is stacked in sequence along the vertical direction.
10. The flow field improvement device as described in claim 9, characterized in that, The height of a single outer cylinder (3) is greater than the height of a single inner cylinder (1) or a single middle cylinder (2).