Chemical vapor infiltration furnace with gas dispersing device

Abstract

The utility model discloses a chemical vapor infiltration furnace with a gas dispersing device, and belongs to the technical field of chemical vapor infiltration furnaces. According to the chemical vapor infiltration furnace with the gas dispersing device, the conical polyhedral gas dispersing device is adopted for effectively dispersing gas at the gas inlet through the arranged gas dispersing openings, and through the method, the gas can be uniformly distributed, so that the contact surfaces of all positions of a substrate and the gas are kept consistent; in addition, the gas dispersing device does not need to be fixed, different types of gas dispersing devices can be replaced at any time according to needs, the needed gas dispersing device can be selected according to the specification of the substrate, the gas is accurately in contact with the substrate, and waste of the gas and raw materials is avoided.

Description

Technical Field

[0001] This utility model belongs to the technical field of chemical vapor permeation furnaces, specifically relating to a chemical vapor permeation furnace with a gas dissipation device. Background Technology

[0002] Chemical vapor infiltration (CVI) is an advanced technology for preparing inorganic materials. Its principle involves decomposing or reacting one or more gaseous compounds at high temperatures, then depositing them into the interior of a porous medium, thereby densifying the material. Currently, CVI is mainly used to manufacture various high-temperature ceramic matrix composites, especially those with carbide and nitride matrices. Furthermore, this technology can also be used to manufacture various impermeable components. By processing at relatively low temperatures, materials with significantly increased melting points can be prepared, while avoiding chemical reactions between fibers and the matrix due to thermodynamic instability during the composite process. With continuous technological advancements, CVI has become capable of preparing some high-performance composite materials that are difficult to achieve using traditional hot-pressing sintering methods.

[0003] In chemical vapor infiltration furnaces, substrates near the inlet tend to form a crust on their surface due to higher gas concentration and flow rate, leading to uneven internal deposition. Conversely, substrates farther from the inlet, with lower gas concentration and flow rate, fail to form good surface deposition, resulting in poor internal deposition and wasted raw materials. Furthermore, the airflow at the inlet is weak, making effective gas diffusion via jetting difficult without external assistance. However, applying external force can affect the furnace's airtightness and increase operating costs. Currently, many gas dispersing devices are fixed to the furnace wall, a design that easily damages the furnace wall, especially under high temperature and pressure conditions, posing a greater challenge to the furnace wall's durability. Summary of the Invention

[0004] The present invention aims to solve the technical problems existing in the prior art and provide a chemical vapor permeation furnace with a gas dissipation device.

[0005] The above-mentioned technical problems of this utility model are mainly solved by the following technical solution: a chemical vapor infiltration furnace with a gas dissipation device, comprising a reactor and a mixing tank, wherein the reactor comprises a reaction chamber and a furnace top, the furnace wall of the reaction chamber is a hollow structure, a water cooling device is provided inside the furnace wall of the reaction chamber, a gas outlet is provided at the top of the furnace top, a gas inlet is provided at the bottom of the reaction chamber, an inlet pipe is connected between the mixing tank and the gas inlet of the reactor, a gas dissipation device is provided at the gas inlet, a base support frame is provided at the bottom of the reaction chamber corresponding to the gas dissipation device, the base support frame is coaxially arranged with the gas inlet, and a base is provided at the top of the base support frame;

[0006] The mixing tank is connected to a raw material tank and a gas tank. Both the raw material tank and the gas tank are connected to the mixing tank through pipelines. Both the raw material tank and the gas tank are equipped with heating devices between themselves and the mixing tank.

[0007] The gas dispersing device includes an inverted cone and a support column for supporting the cone. The cone is a hollow structure with an open bottom, and the bottom of the cone is located in the air inlet of the reaction chamber. The top of the cone has multiple gas dispersing holes that radiate outwards.

[0008] Preferably, the cone is mounted at the same height as the air inlet by a support column.

[0009] Preferably, the water cooling device includes a hot water exchange pipe spirally wound inside the furnace wall of the reaction chamber.

[0010] Preferably, the furnace top and the reactor are detachable.

[0011] The beneficial effects of this utility model are as follows: This solution provides a chemical vapor infiltration furnace with a gas dispersion device. The device uses a conical polyhedral gas dispersion device to effectively disperse the gas from the inlet through the set gas dispersion port. In this way, not only can the gas be evenly distributed, ensuring that the contact surface between the gas and various positions of the substrate is consistent, but it also avoids the use of additional external force, thereby effectively controlling costs. In addition, the gas dispersion device does not need to be fixed and can be replaced with different models as needed. The required gas dispersion device can be selected according to the specifications of the substrate to ensure that the gas is in precise contact with the substrate, avoiding waste of gas and raw materials. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model;

[0013] Figure 2 This is a schematic diagram of the structure of the gas dispersing device of this utility model;

[0014] Figure 3 This is a schematic diagram of the structure of a hot water exchange pipe according to this utility model.

[0015] In the diagram: 1. Reactor; 2. Mixing tank; 3. Reaction chamber; 4. Furnace top; 5. Water cooling device; 6. Gas outlet; 7. Gas inlet; 8. Gas inlet pipe; 9. Gas dissipation device; 10. Base support frame; 11. Base; 12. Raw material tank; 13. Gas tank; 14. Heating device; 15. Cone; 16. Support column; 17. Gas dissipation hole; 18. Hot water exchanger pipe. Detailed Implementation

[0016] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0017] Example: A chemical vapor permeation furnace with a gas dissipation device, such as Figures 1-3 As shown, the reactor includes a reactor 1 and a mixing tank 2. The reactor 1 includes a reaction chamber 3 and a furnace top 4. The furnace wall of the reaction chamber 3 is hollow, and a water cooling device 5 is installed inside the furnace wall. The top of the furnace top 4 has a gas outlet 6, and the bottom of the reaction chamber 3 has a gas inlet 7. An inlet pipe 8 connects the mixing tank 2 and the gas inlet 7 of the reactor 1. A gas dissipation device 9 is installed at the outlet 7. A base support frame 10 is installed at the bottom of the reaction chamber 3 corresponding to the gas dissipation device 9. The base support frame 10 is coaxially arranged with the gas inlet 7, and the base support frame 10... The top of the 0 is provided with a base 11; the mixing tank 2 is connected to a raw material tank 12 and a gas tank 13, both of which are connected to the mixing tank 2 through pipelines, and both of which are provided with heating devices 14 between the raw material tank 12 and the gas tank 13 and the mixing tank 2; the gas dispersing device 9 includes an inverted cone 15 and a support column 16 for supporting the cone 15, the cone 15 is a hollow structure with an open bottom, and the bottom of the cone 15 is located in the air inlet 7 of the reaction chamber 3, and the top of the cone 15 is provided with a plurality of gas dispersing holes 17 that radiate outwards.

[0018] The cone 15 is supported by a support column 16 at the same height as the air inlet; the water cooling device 5 includes a hot water exchange pipe 18 spirally wound inside the furnace wall of the reaction chamber 3; the furnace top 4 and the reaction furnace 1 are detachable.

[0019] The principle of this utility model is as follows: In order to control the furnace wall temperature after the reaction starts, a water cooling device 5 is provided inside the furnace wall; the gas outlet 6 is located at the top of the furnace 4, the gas inlet is located at the bottom of the furnace, the base support frame 10 is located on both sides of the gas inlet, the base 11 is placed on the gas dispersing device 9, and the bottom of the gas dispersing device 9 is at the same level as the gas inlet. If the gas dispersing device 9 is inserted into the gas inlet pipe 8, the airflow will return to the gas inlet pipe after contacting the gas dispersing device 9 and form a vortex therein, thereby affecting the gas flow. Therefore, the gas dispersing device 9 is not placed in the gas hole.

[0020] The air inlet pipe 8 is connected to the mixing tank, which is connected to the raw material tank and the gas tank 13 through two pipes respectively. In order to ensure that the two gases entering the mixing tank are at similar temperatures, both pipes are equipped with heating devices 14.

[0021] By adjusting the size and direction of the vent 17, the flow of gas can be controlled to achieve precise regulation of the reaction gas and to evenly disperse the airflow around the device.

[0022] The advantages of this device are that it avoids the traditional drilling and fixing method, and the air diffuser 9 can be replaced with different sizes at any time, offering high flexibility and reusability. In addition, the shape of the air diffuser 9 can be adjusted according to the specific shape of the air inlet, and it can even be designed as a conical polyhedron to meet different needs.

[0023] Finally, it should be noted that the above embodiments are merely representative examples of this utility model. Obviously, this utility model is not limited to the above embodiments and can have many variations. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this utility model should be considered to fall within the protection scope of this utility model.

Claims

1. A chemical vapor permeation furnace with a gas dissipation device, comprising a reactor (1) and a mixing tank (2), characterized in that: The reactor (1) includes a reaction chamber (3) and a furnace top (4). The furnace wall of the reaction chamber (3) is a hollow structure. A water cooling device (5) is provided inside the furnace wall of the reaction chamber (3). An outlet (6) is provided at the top of the furnace top (4). An inlet (7) is provided at the bottom of the reaction chamber (3). An inlet pipe (8) is connected between the mixing tank (2) and the inlet (7) of the reactor (1). A gas dissipation device (9) is provided at the outlet (7). A base support frame (10) is provided at the bottom of the reaction chamber (3) corresponding to the gas dissipation device (9). The base support frame (10) is coaxial with the inlet (7), and a base (11) is provided at the top of the base support frame (10). The mixing tank (2) is connected to a raw material tank (12) and a gas tank (13). Both the raw material tank (12) and the gas tank (13) are connected to the mixing tank (2) through pipelines. Both the raw material tank (12) and the gas tank (13) are equipped with heating devices (14) between themselves and the mixing tank (2). The gas dispersing device (9) includes an inverted cone (15) and a support column (16) for supporting the cone (15). The cone (15) is a hollow structure with an open bottom, and the bottom of the cone (15) is located in the air inlet (7) of the reaction chamber (3). The top of the cone (15) has a plurality of gas dispersing holes (17) that radiate outwards.

2. A chemical vapor permeation furnace with a gas dissipation device according to claim 1, characterized in that: The cone (15) is mounted at the same height as the air inlet via a support column (16).

3. A chemical vapor permeation furnace with a gas dissipation device according to claim 1, characterized in that: The water cooling device (5) includes a hot water exchange pipe (18) spirally wound inside the furnace wall of the reaction chamber (3).

4. A chemical vapor permeation furnace with a gas dissipation device according to claim 1, characterized in that: The furnace top (4) and the reactor (1) are detachable structures.

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