Graphene composite film preparation device with wave absorbing function

Abstract

The invention relates to the technical field of graphene film production, in particular to a graphene composite film preparation device with a wave absorbing function, which comprises a mounting plate, a box body is fixed at the center of the top of the mounting plate, and a heating plate for heating a substrate is fixedly mounted in the box body; clamps for clamping a base plate are symmetrically fixed to the top of the heating plate, a vacuum pump for vacuumizing the box body is fixed to the top of the mounting plate, one side of the box body is connected with an air inlet assembly through an air inlet pipe, and in the process that the vacuum pump is started to exhaust air in the box body, a first valve is opened, a motor drives fan blades to rotate in the forward direction; the fan blades rotate in the cylinder, so that air flow from top to bottom is generated in the cylinder, dust remaining on the base plate can float through impact of the air flow, then the dust is brought out in the flowing process of the air flow, and the effect of cleaning the base plate is achieved.

Description

Technical Field

[0001] This invention relates to the field of graphene film production technology, and in particular to an apparatus for preparing graphene composite films with wave-absorbing function. Background Technology

[0002] Graphene possesses a linear band structure where the conduction and valence bands intersect, resulting in a zero bandwidth. This means that graphene can absorb electromagnetic waves of various frequencies. Due to its unique band structure and high electron density, graphene exhibits excellent microwave absorption properties. It can achieve efficient absorption not only in the microwave and infrared bands but also has the potential for broad absorption in the visible light band. This makes graphene a promising candidate for applications in materials science, electronics, and optics.

[0003] A CVD graphene fabrication device and a method for preparing graphene films are disclosed in patent publication number CN112938945B. This invention provides a CVD graphene fabrication device, including a support base, a graphene growth substrate, and a top cover. The support base has an annular closed structure with a through-hole at the top, and a fixing post is provided on the inner wall of one of the through-holes. The fixing end of the graphene growth substrate is bent and has an opening adapted to the fixing post. A fixing plate is provided on the inner wall of the top cover, and the fixing plate has an opening adapted to the fixing post.

[0004] In the process of preparing graphene films by chemical vapor deposition (CVD), tools such as lint-free cloths and brushes are usually used to remove dust and particles from the substrate surface. However, during the substrate processing, if there is dust on the tools used by the operator, there is a risk that the dust on the tools may fall onto the substrate, resulting in tiny particles and dust on the substrate surface. During the growth process, graphene may form aggregates or voids around the dust, which will affect the uniformity of the film. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies where, during operation, dust on the tools may fall onto the substrate, causing tiny particles and dust to form on the substrate surface. During the growth process, graphene may aggregate or form voids around the dust, affecting the uniformity of the film. The invention proposes a graphene composite film preparation device with wave-absorbing function.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a graphene composite film preparation device with wave absorption function, including a mounting plate, a box fixed at the top center of the mounting plate, a heating plate for heating the substrate fixedly installed inside the box, a clamp for holding the substrate symmetrically fixed at the top of the heating plate, a vacuum pump for evacuating the box fixed at the top of the mounting plate, an air intake assembly connected to one side of the box through an air intake pipe, and an airflow circulation assembly installed at the top inside the box.

[0007] During the vacuuming process, the airflow circulation component generates a downward airflow that impacts the top of the substrate, blowing away the dust remaining on the top of the substrate. As the air intake component draws air into the chamber, the airflow circulation component agitates the incoming airflow, thoroughly mixing the airflow entering the chamber.

[0008] In a further embodiment, the airflow circulation assembly includes a cylinder fixed to the inner top side wall of the housing, a fan blade installed inside the cylinder via a rotating assembly, and a connecting pipe fixedly connected to the outer wall of the cylinder.

[0009] In a further embodiment, the rotating assembly includes a support frame, which is fixedly installed on the top of the housing. A motor is fixed to the top of the support frame, and the output shaft of the motor passes through the support frame and is fixed with a rotating rod. The end of the rotating rod away from the motor passes through the top side wall of the housing and is fixed with a fan blade, which is located inside the cylinder.

[0010] In a further embodiment, a mounting shell is fixed to the top of the heating plate, and the end of the connecting pipe away from the cylinder is fixedly connected to the top of the mounting shell. An air outlet is fixedly opened on the side of the mounting shell facing the clamp.

[0011] In a further embodiment, the air intake assembly includes a first air intake pipe and a second air intake pipe. The first air intake pipe is fixedly connected to the outer wall of the air intake pipe, and a first one-way valve is provided at the air outlet end of the first air intake pipe. The second air intake pipe is fixedly connected to the outer wall of the air intake pipe, and a second one-way valve is provided at the air outlet end of the second air intake pipe.

[0012] In a further embodiment, the heating plate has a heating cavity inside, and a heater is fixed to the top of the heating cavity;

[0013] An inclined plate is fixedly installed inside the housing, and the inclined plate is located on the side of the air outlet of the air inlet pipe.

[0014] In a further embodiment, a combustion chamber is provided at the top center of the mounting plate, and an opening is provided at the bottom of the box body. The heating chamber and the combustion chamber are connected through the opening. A second valve is installed inside the opening, and a heat-conducting plate is installed inside the heating chamber.

[0015] The vacuum pump has a fixed connection to the outlet end via a connecting pipe. The end of the connecting pipe away from the vacuum pump passes through the bottom of the mounting plate and connects to the combustion chamber.

[0016] In a further embodiment, an air pump is fixed to the top of the mounting plate, and an air supply pipe is fixedly connected to the air outlet end of the air pump. The end of the air supply pipe away from the air pump passes through the mounting plate and connects to the combustion chamber. A first exhaust pipe is fixedly connected to the inner wall of the combustion chamber. The end of the first exhaust pipe away from the combustion chamber passes through the inner wall of the mounting plate, and the end of the first exhaust pipe away from the combustion chamber is located above the mounting plate.

[0017] In a further embodiment, a preheating box is fixed to one end of the air inlet pipe away from the box body, a first exhaust pipe is fixedly connected to the bottom of the preheating box, and a second exhaust pipe is fixedly connected to one side of the top of the preheating box.

[0018] The upper part of the preheating box is fitted onto the outer wall of the first air inlet pipe, and the lower part of the preheating box is fitted onto the outer wall of the second air inlet pipe.

[0019] In a further embodiment, a purification box is fixed to the top of the mounting plate, and the end of the second exhaust pipe away from the preheating box passes through the top of the purification box and enters the interior of the purification box. The interior of the purification box contains purification liquid, and the exhaust end of the second exhaust pipe is located inside the purification liquid. A discharge pipe is fixedly connected to one side of the top of the purification box.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. This invention, through the arrangement of the fan blades, allows the first valve to open during the vacuum pump's operation to evacuate the interior of the chamber. The motor drives the fan blades to rotate forward, creating a downward airflow within the cylinder. This airflow impact causes dust remaining on the substrate to float up and be carried out, effectively cleaning the substrate. During the intake process, the first valve closes, and the motor drives the fan blades to rotate in reverse, creating an upward airflow within the cylinder. This airflow circulates within the chamber, facilitating the mixing of gases and allowing the vacuum pump to expel all air.

[0022] 2. Through the design of the combustion chamber, the gas extracted by the vacuum pump is also at a high temperature due to the high temperature inside the chamber. After the mixed gas enters the combustion chamber through the connecting pipe, the high-temperature hydrogen and methane mixture spontaneously combusts upon contact with air. The combustion occurs inside the combustion chamber, and the flame generated by the combustion passes through the opening and contacts the bottom of the heat-conducting plate, thereby heating the heat-conducting plate. The heat from the heat-conducting plate is transferred to the heating plate through heat conduction, which helps to maintain the substrate temperature at around 1000℃, within a stable temperature fluctuation range.

[0023] 3. By setting up an inclined plate, the gas entering the box from the air inlet pipe is blown onto the inclined plate, flows along the inclined plate and rotates inside the box, and forms a vortex along the inner wall of the box, which increases the disturbance effect on the gas inside the box, thereby facilitating the full mixing of methane and hydrogen, making the methane concentration inside the box uniform, and thus making the methane concentration in the mixed gas in contact with the substrate uniform.

[0024] 4. This invention utilizes an airflow circulation component. A motor drives the fan blades to rotate forward, generating airflow that cleans dust from the substrate surface. When hydrogen is introduced into the housing, the motor drives the fan blades to rotate in reverse, causing airflow circulation and increasing airflow disturbance, thus accelerating the removal of air from the housing. When methane gas is introduced into the housing, the airflow disturbance ensures a uniform methane concentration inside the housing, and a protective airflow is generated through the air outlet, achieving uniform contact between methane and the substrate surface. During the cooling process of the substrate, the airflow circulation accelerates the contact between air and the inner wall of the housing, speeding up the dissipation of heat from the inside of the housing, thereby indirectly accelerating the heat dissipation of the substrate. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the first overall structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the second overall structure of the present invention;

[0027] Figure 3 This is a cross-sectional view of the overall structure of the present invention;

[0028] Figure 4 For the present invention Figure 3 Enlarged view of the structure at point A in the middle;

[0029] Figure 5 This is a cross-sectional view of the preheating box of the present invention;

[0030] Figure 6 This is a cross-sectional view of the housing of the present invention;

[0031] Figure 7This is a cross-sectional view of the internal structure of the housing of the present invention.

[0032] In the diagram: 1. Mounting plate; 2. Housing; 3. Clamp; 4. Heating plate; 5. Heater; 6. Air inlet pipe; 7. Air outlet pipe; 8. Vacuum pump; 9. Air inlet; 10. First valve; 11. Support frame; 12. Motor; 13. Rotating rod; 14. Fan blade; 15. Cylinder; 16. First air inlet pipe; 17. First one-way valve; 18. Inclined plate; 19. Connecting pipe; 20. Mounting shell; 21. Air outlet; 22. Second air inlet pipe; 23. Second one-way valve; 24. Connecting pipe; 25. Combustion chamber; 26. Air pump; 27. Air supply pipe; 28. First exhaust pipe; 29. ​​Preheating box; 30. Second exhaust pipe; 31. Purification box; 32. Second valve; 33. Heat-conducting plate; 34. Door. Detailed Implementation

[0033] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0034] like Figures 1 to 7 The graphene composite film preparation device with wave absorption function shown includes a mounting plate 1, a box 2 fixed at the top center of the mounting plate 1, a heating plate 4 for heating the substrate fixedly installed inside the box 2, a clamp 3 for holding the substrate symmetrically fixed on the top of the heating plate 4, a vacuum pump 8 for evacuating the box 2 fixed on the top of the mounting plate 1, an air intake assembly connected to one side of the box 2 through an air intake pipe 6, and an airflow circulation assembly installed on the inner top of the box 2.

[0035] During the vacuuming process, the airflow circulation component generates a downward airflow that impacts the top of the substrate, blowing away the dust remaining on the top of the substrate. During the process of the air intake component drawing air into the housing 2, the airflow circulation component disturbs the incoming airflow and fully mixes the airflow entering the housing 2.

[0036] In the specific implementation process, a door 34 is hinged to one side of the box 2, and an air outlet pipe 7 is fixedly connected to one side of the box 2. The air outlet end of the air outlet pipe 7 is fixedly connected to the air inlet end of the vacuum pump 8.

[0037] Specifically, if there is dust on the tools used by the operator, there is a risk that the dust may fall onto the substrate, causing tiny particles and dust to form on the substrate surface. During the growth process, graphene may form aggregates or voids around the dust, which will affect the uniformity of the film.

[0038] This embodiment of the invention can solve the above problems. The specific implementation method is as follows: First, the operator opens the box door 34, then places the substrate on top of the heating plate 4, and uses two clamps 3 to clamp the substrate placed on top of the heating plate 4 to prevent the substrate from moving. Then, the box door 34 is closed, and the operator starts the vacuum pump 8. The vacuum pump 8 extracts the air inside the box 2 to achieve the purpose of venting the air inside the box 2. After the air inside the box 2 is extracted, the air pressure inside the box 2 decreases. After the air pressure inside the box 2 decreases, the external atmospheric pressure is squeezed on the side wall of the box door 34, which helps to increase the sealing between the box door 34 and the box 2. On the other hand, the vacuum pump 8 will...

[0039] During the process of vacuum pump 8 evacuating the inside of chamber 2, the staff activates the airflow circulation component. The airflow circulation component generates a downward airflow inside chamber 2 that impacts the top of the substrate. The impact of the airflow causes the dust remaining on the substrate to be suspended, and then the dust is discharged to the outside of chamber 2 during the airflow process.

[0040] After the vacuum pump 8 extracts air from the inside of the chamber 2 for a period of time, the staff starts the air intake component to fill the chamber 2 with hydrogen. At this time, under the action of the air circulation component, the hydrogen filled into the chamber 2 is fully mixed with the residual air inside the chamber 2. Then, under the continuous pumping action of the vacuum pump 8, the air inside the chamber 2 is completely exhausted.

[0041] Then, the staff started heating the substrate to 1000°C using the heating plate 4, and then introduced methane gas into the chamber 2 through the air intake component. The methane gas and hydrogen gas inside the chamber 2 were fully mixed by the airflow circulation component, and a graphene film was generated on the surface of the substrate.

[0042] It should be noted that in the process of preparing graphene films by chemical vapor deposition (CVD), specific doping or structural modulation is required to obtain graphene films with microwave absorption capabilities. Specifically, a mixed gas containing nitrogen and hydrogen is introduced during the CVD process. By adjusting the nitrogen concentration, the degree of nitrogen doping in the graphene film can be controlled. Nitrogen atoms replace carbon atoms in graphene, forming nitrogen-carbon covalent bonds. This substitution alters the electronic structure of graphene, transforming it from a semiconductor into a metal or half-metal, thereby acquiring microwave absorption properties.

[0043] As an optional implementation, the clamp 3 includes a U-shaped frame, which is fixed to the top of the heating plate 4. The top of the U-shaped frame is threaded with a bolt, and a pressure plate is slidably connected inside the U-shaped frame. The top of the pressure plate is rotatably connected to the lower end of the bolt.

[0044] In a further implementation, the airflow circulation assembly includes a cylinder 15, which is fixed to the inner top side wall of the housing 2. A fan blade 14 is installed inside the cylinder 15 via a rotating assembly, and a connecting pipe 19 is fixedly connected to the outer wall of the cylinder 15.

[0045] The rotating assembly includes a support frame 11, which is fixedly installed on the top of the housing 2. A motor 12 is fixed on the top of the support frame 11. The output shaft of the motor 12 passes through the support frame 11 and is fixed with a rotating rod 13. The end of the rotating rod 13 away from the motor 12 passes through the top side wall of the housing 2 and is fixed with a fan blade 14. The fan blade 14 is located inside the cylinder 15.

[0046] In the specific implementation process, an air inlet 9 is provided on the top of the box 2, and a first valve 10 is fixedly installed inside the air inlet 9. The port of the air inlet 9 located inside the box 2 is located inside the cylinder 15.

[0047] Specifically, during the process of vacuum pump 8 starting to evacuate the inside of chamber 2, the first valve 10 is opened, and the operator starts motor 12. Motor 12 drives rotating rod 13 to rotate, and rotating rod 13 drives fan blade 14 to rotate in the forward direction. The rotation of fan blade 14 inside cylinder 15 causes airflow to be generated inside cylinder 15 from top to bottom. The generated airflow impacts the top of the substrate from top to bottom. The impact of the airflow can make the dust remaining on the substrate float up, and then be carried out in the flow of air, which plays a role in cleaning the substrate.

[0048] During the process of the air intake assembly filling the chamber 2 with air, the first valve 10 is closed. Then, the motor 12 drives the rotating rod 13 to rotate in the opposite direction, and the rotating rod 13 drives the fan blade 14 to rotate in the opposite direction, thereby generating an upward airflow inside the cylinder 15. The gas inside the chamber 2 enters the cylinder 15 from the bottom, then enters the connecting pipe 19 from the cylinder 15, and then is discharged into the chamber 2 from the outlet of the connecting pipe 19, thus completing the airflow circulation. During the airflow circulation, the hydrogen gas filled into the chamber 2 mixes thoroughly with the residual air inside the chamber 2, and is then extracted by the vacuum pump 8, which helps to fully discharge the air inside the chamber 2 to the outside of the chamber 2.

[0049] In a further implementation process, a mounting shell 20 is fixed to the top of the heating plate 4, and the end of the connecting pipe 19 away from the cylinder 15 is fixedly connected to the top of the mounting shell 20. An air outlet 21 is fixedly opened on the side of the mounting shell 20 facing the clamp 3.

[0050] It should be noted that the air outlet 21 can transform the flowing air into a horizontal protective airflow. This protective airflow can block the impact of airflow from other directions in the housing 2 on the top of the substrate, thereby creating a stable gas environment for the top of the substrate, which is conducive to the uniform growth of the graphene film.

[0051] Specifically, as the fan blade 14 reverses, causing an upward airflow inside the cylinder 15, the airflow inside the cylinder 15 enters the connecting pipe 19, and then enters the interior of the mounting shell 20 from the outlet end of the connecting pipe 19. Subsequently, it is discharged into the interior of the housing 2 from the air outlet 21 opened on one side of the mounting shell 20. The airflow generates a transverse protective airflow at the air outlet 21 and is transported into the interior of the housing 2 from the air outlet 21. The generated protective airflow can provide a stable gas flow rate and uniform gas distribution, which is beneficial to the uniform growth of the graphene film.

[0052] Meanwhile, after the air intake component fills the interior of the housing 2 with hydrogen and methane, the mixed gas of hydrogen and methane is fully mixed under the action of the airflow. The uniformly mixed gas is blown out from the air outlet 21 and contacts the top of the substrate, which helps to make the graphene film generated on the substrate more uniform.

[0053] In a further implementation process, the air intake assembly includes a first air intake pipe 16 and a second air intake pipe 22. The first air intake pipe 16 is fixedly connected to the outer wall of the air intake pipe 6, and a first one-way valve 17 is provided at the air outlet end of the first air intake pipe 16. The second air intake pipe 22 is fixedly connected to the outer wall of the air intake pipe 6, and a second one-way valve 23 is provided at the air outlet end of the second air intake pipe 22.

[0054] It should be noted that flow controllers for controlling the airflow inside the first air intake pipe 16 and the second air intake pipe 22 are fixed on the outer walls of both the first air intake pipe 16 and the second air intake pipe 22. The flow controllers control the concentration of methane in the mixture of methane and hydrogen to be below 5%.

[0055] Specifically, the inlet end of the first inlet pipe 16 is connected to an external hydrogen storage tank, and the inlet end of the second inlet pipe 22 is connected to an external methane storage tank. After the vacuum pump 8 has been running for a period of time, the first inlet pipe 16 supplies hydrogen into the air inlet pipe 6. After the hydrogen is injected into the box 2 and mixed with the residual air, the vacuum pump 8 extracts the mixed gas from the box 2 again. After multiple extractions, the air inside the box 2 is completely removed.

[0056] The first one-way valve 17 is used to prevent gas inside the air inlet pipe 6 from entering the first air inlet pipe 16, and the second one-way valve 23 is used to prevent gas inside the air inlet pipe 6 from entering the second air inlet pipe 22.

[0057] After the substrate is heated to 1000°C, the second air inlet pipe 22 delivers methane gas into the air inlet pipe 6. The methane gas mixes with hydrogen gas and comes into contact with the high-temperature substrate, generating a graphene film on the surface of the substrate.

[0058] In a further implementation process, a heating cavity is provided inside the heating plate 4, and a heater 5 is fixed to the top of the inner cavity;

[0059] An inclined plate 18 is fixedly installed inside the housing 2, and the inclined plate 18 is located on the side of the air outlet of the air inlet pipe 6.

[0060] Specifically, after the air inside the housing 2 is purged, the staff starts the heater 5 to heat the heating plate 4. The heating plate 4 transfers heat to the substrate through heat conduction, thereby raising the temperature of the substrate to 1000℃.

[0061] The gas entering the housing 2 from the air inlet pipe 6 is blown onto the inclined plate 18 and flows along the inclined plate 18 and rotates inside the housing 2, which increases the disturbance effect on the gas inside the housing 2, thereby facilitating the full mixing of methane and hydrogen and making the concentration of methane in the mixed gas in contact with the substrate uniform.

[0062] In a further implementation process, a combustion chamber 25 is provided at the top center of the mounting plate 1, and an opening is provided at the bottom of the box body 2. The heating chamber and the combustion chamber 25 are connected through the opening. A second valve 32 is installed inside the opening, and a heat-conducting plate 33 is installed inside the heating chamber.

[0063] The outlet end of the vacuum pump 8 is fixedly connected to a connecting pipe 24. The end of the connecting pipe 24 away from the vacuum pump 8 passes through the bottom of the mounting plate 1 and is connected to the combustion chamber 25.

[0064] Specifically, the gas extracted from the vacuum pump 8 enters the connecting pipe 24, flows through the connecting pipe 24 and then enters the combustion chamber 25. During the process of introducing methane and hydrogen into the chamber 2, in order to keep the concentration of methane gas inside the chamber 2 stable, the vacuum pump 8 needs to be started continuously to extract the gas inside the chamber 2 at a certain speed.

[0065] Because the interior of chamber 2 is at a high temperature, the gas extracted by vacuum pump 8 is also at a high temperature. After the mixed gas enters combustion chamber 25 through connecting pipe 24, the high-temperature hydrogen and methane mixture spontaneously combusts upon contact with air and burns inside combustion chamber 25. The flame generated by combustion passes through the opening and contacts the bottom of heat-conducting plate 33, thereby heating heat-conducting plate 33. The heat from heat-conducting plate 33 is transferred to heating plate 4 through heat conduction, which helps to maintain the substrate temperature at around 1000℃, within a stable temperature fluctuation range.

[0066] When the temperature of the substrate exceeds 1000°C, the second valve 32 closes, blocking the flame generated by combustion outside the heating chamber, thereby preventing the substrate temperature from becoming too high due to overheating.

[0067] In a further implementation process, an air pump 26 is fixed to the top of the mounting plate 1. An air supply pipe 27 is fixedly connected to the air outlet end of the air pump 26. The end of the air supply pipe 27 away from the air pump 26 passes through the mounting plate 1 and connects to the combustion chamber 25. A first exhaust pipe 28 is fixedly connected to the inner wall of the combustion chamber 25. The end of the first exhaust pipe 28 away from the combustion chamber 25 passes through the inner wall of the mounting plate 1. The end of the first exhaust pipe 28 away from the combustion chamber 25 is located above the mounting plate 1.

[0068] Specifically, under the action of the air pump 26, outside air is sent into the interior of the air supply pipe 27, and then enters the interior of the combustion chamber 25 from the air supply pipe 27 to provide oxygen for combustion inside the combustion chamber 25. Subsequently, the harmful gases produced by combustion inside the combustion chamber 25 and the residual unburned gases are pushed into the first exhaust pipe 28 by the air pump 26.

[0069] In a further implementation process, a preheating box 29 is fixed to the end of the air inlet pipe 6 away from the box 2, the bottom of the preheating box 29 is fixedly connected to the first exhaust pipe 28, and the top side of the preheating box 29 is fixedly connected to the second exhaust pipe 30.

[0070] The upper part of the preheating box 29 is fitted onto the outer wall of the first air inlet pipe 16, and the lower part of the preheating box 29 is fitted onto the outer wall of the second air inlet pipe 22.

[0071] Specifically, after the gas extracted by the vacuum pump 8 is burned inside the combustion chamber 25, the resulting water vapor, carbon dioxide, carbon monoxide, and some air enter the first exhaust pipe 28 and then enter the preheating box 29 along the first exhaust pipe 28. The gas produced inside the combustion chamber 25 is all high-temperature gas, which can heat the first intake pipe 16 and the second intake pipe 22 when it enters the preheating box 29. The heat is transferred from the gas to the pipe walls of the first intake pipe 16 and the second intake pipe 22, and then from the pipe walls of the first intake pipe 16 and the second intake pipe 22 to the interior, heating the hydrogen and methane gas, thus achieving a preheating effect. This avoids the situation where the temperature of hydrogen and methane is too low when they enter the box 2, causing a drastic drop in temperature.

[0072] In a further implementation process, a purification box 31 is fixed to the top of the mounting plate 1. The end of the second exhaust pipe 30 away from the preheating box 29 passes through the top of the purification box 31 and enters the interior of the purification box 31. The interior of the purification box 31 contains purification liquid. The exhaust end of the second exhaust pipe 30 is located inside the purification liquid. A discharge pipe is fixedly connected to one side of the top of the purification box 31.

[0073] In the specific implementation process, the purification box 31 contains an alkaline solution, specifically a sodium hydroxide solution.

[0074] Specifically, the high-temperature gas inside the combustion chamber 25 enters the preheating box 29 along the first exhaust pipe 28. Inside the preheating box 29, the gas moves from the bottom to the top and then enters the second exhaust pipe 30 connected to the top side of the preheating box 29. From the second exhaust pipe 30, the gas enters the purification box 31 and reacts chemically with the sodium hydroxide solution, thereby treating the mixed gas to meet the emission standards.

[0075] Working principle of this invention:

[0076] When using this invention, firstly, the operator opens the box door 34, then places the substrate on the heating plate 4, and then uses two symmetrically arranged clamps 3 to hold the two sides of the substrate and press the substrate firmly onto the heating plate 4.

[0077] Then, the staff closed the box door 34, started the vacuum pump 8 and the motor 12 and opened the first valve 10. After the vacuum pump 8 started, it generated a suction force to draw the air inside the box 2 out of the air outlet 7, and the outside air entered the inside of the box 2 through the air inlet 9. After the motor 12 started, it drove the fan blade 14 to rotate forward through the rotating rod 13. The rotation of the fan blade 14 caused the airflow inside the cylinder 15 to be generated from top to bottom. The airflow impacted the top of the substrate and cleaned the dust on the surface of the substrate.

[0078] After the airflow impacts the top of the substrate for a period of time, the first valve 10 is closed and the motor 12 drives the fan blade 14 to reverse. After the first valve 10 is closed, under the action of the vacuum pump 8, the air inside the box 2 is extracted, which reduces the air pressure inside the box 2. Then, the operator delivers hydrogen into the box 2 from the first air inlet pipe 16. The motor 12 drives the fan blade 14 to reverse, and the airflow inside the box 2 enters the cylinder 15 from the box 2, then enters the connecting pipe 19 from the cylinder 15, and then enters the box 2 from the connecting pipe 19, completing the airflow circulation to increase the disturbance of the airflow inside the box 2 and accelerate the mixing of hydrogen and air. Under the action of the vacuum pump 8, the air is extracted. After multiple times, it is beneficial to completely exhaust the air inside the box 2.

[0079] After the air inside the housing 2 is purged, the heater 5 is activated to heat the substrate to 1000°C.

[0080] After heating the substrate to 1000°C, the temperature is maintained within a stable range. Methane gas is then introduced into the interior of the housing 2 through the second air inlet pipe 22. The motor 12 drives the fan blades 14 to reverse, generating a circulating airflow to accelerate the mixing of hydrogen and methane gas. At the same time, the airflow is discharged from the air outlet 21, generating a lateral protective airflow, which ensures that the mixed gas is in uniform contact with the top of the substrate, which is beneficial for the uniform formation of the graphene film.

[0081] After the graphene film is generated, the vacuum pump 8 is turned off and the delivery of hydrogen and methane gas and the heating of heater 5 are stopped. The motor 12 is started to drive the fan blade 14 to rotate, which agitates the gas inside the chamber 2, so that the gas inside the chamber 2 can fully contact the interior of the chamber 2, which helps to accelerate the cooling of the gas inside the chamber 2, and thus accelerates the cooling of the substrate. After the cooling is completed, the chamber door 34 is opened and the substrate is taken out.

[0082] The motor 12 drives the fan blades 14 to rotate forward, generating a downward airflow that cleans the dust from the substrate surface. After hydrogen is introduced into the housing 2, the motor 12 drives the fan blades 14 to rotate in reverse, causing airflow circulation and increasing the disturbance of the airflow, which accelerates the exhaust of air from the housing 2. After methane gas is introduced into the housing 2, the disturbance of the airflow makes the concentration of methane in the housing 2 uniform, and the horizontal protective airflow generated through the air outlet 21 achieves the purpose of uniform contact between methane and the substrate surface. During the cooling process of the substrate, the airflow circulation accelerates the contact between the air and the inner wall of the housing 2, and accelerates the speed at which the gas inside the housing 2 dissipates heat to the outside, thereby indirectly accelerating the heat dissipation speed of the substrate.

[0083] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A graphene composite film preparation device with wave-absorbing function, comprising a mounting plate (1), characterized in that, A box (2) is fixed at the top center of the mounting plate (1). A heating plate (4) for heating the substrate is fixedly installed inside the box (2). A clamp (3) for holding the substrate is symmetrically fixed on the top of the heating plate (4). A vacuum pump (8) for evacuating the box (2) is fixed on the top of the mounting plate (1). An air intake assembly is connected to one side of the box (2) through an air intake pipe (6). An airflow circulation assembly is installed on the top of the inner side of the box (2). During the vacuuming process, the airflow circulation component generates an airflow from top to bottom that impacts the top of the substrate, blowing away the dust remaining on the top of the substrate. During the process of the air intake component introducing air into the housing (2), the airflow circulation component disturbs the incoming airflow and fully mixes the airflow entering the housing (2).

2. The apparatus for preparing graphene composite films with wave-absorbing function according to claim 1, characterized in that, The airflow circulation assembly includes a cylinder (15), which is fixed on the inner top side wall of the box (2). A fan blade (14) is installed inside the cylinder (15) through a rotating assembly, and a connecting pipe (19) is fixedly connected to the outer wall of the cylinder (15).

3. The apparatus for preparing graphene composite films with wave-absorbing function according to claim 2, characterized in that, The rotating assembly includes a support frame (11), which is fixedly installed on the top of the housing (2). A motor (12) is fixed on the top of the support frame (11). The output shaft of the motor (12) passes through the support frame (11) and is fixed with a rotating rod (13). The end of the rotating rod (13) away from the motor (12) passes through the top side wall of the housing (2) and is fixed with a fan blade (14). The fan blade (14) is located inside the cylinder (15).

4. The apparatus for preparing graphene composite films with wave-absorbing function according to claim 3, characterized in that, The top of the heating plate (4) is fixed with a mounting shell (20), and the end of the connecting pipe (19) away from the cylinder (15) is fixedly connected to the top of the mounting shell (20). An air outlet (21) is fixedly opened on the side of the mounting shell (20) facing the clamp (3).

5. The apparatus for preparing graphene composite films with wave-absorbing function according to claim 1, characterized in that, The air intake assembly includes a first air intake pipe (16) and a second air intake pipe (22). The first air intake pipe (16) is fixedly connected to the outer wall of the air intake pipe (6). A first one-way valve (17) is provided at the air outlet end of the first air intake pipe (16). The second air intake pipe (22) is fixedly connected to the outer wall of the air intake pipe (6). A second one-way valve (23) is provided at the air outlet end of the second air intake pipe (22).

6. The apparatus for preparing graphene composite films with wave-absorbing function according to claim 5, characterized in that, The heating plate (4) has a heating cavity inside, and a heater (5) is fixed to the top of the heating cavity. An inclined plate (18) is fixedly installed inside the housing (2), and the inclined plate (18) is located on the side of the air outlet of the air inlet pipe (6).

7. The apparatus for preparing graphene composite films with wave-absorbing function according to claim 6, characterized in that, The mounting plate (1) has a combustion chamber (25) at the top center, and the box body (2) has an opening at the bottom. The heating chamber and the combustion chamber (25) are connected through the opening. A second valve (32) is installed inside the opening, and a heat-conducting plate (33) is installed inside the heating chamber. The outlet end of the vacuum pump (8) is fixedly connected to a connecting pipe (24), and the end of the connecting pipe (24) away from the vacuum pump (8) passes through the bottom of the mounting plate (1) and is connected to the combustion chamber (25).

8. The apparatus for preparing graphene composite films with wave-absorbing function according to claim 7, characterized in that, An air pump (26) is fixed to the top of the mounting plate (1). An air supply pipe (27) is fixedly connected to the air outlet end of the air pump (26). The end of the air supply pipe (27) away from the air pump (26) passes through the mounting plate (1) and connects to the combustion chamber (25). A first exhaust pipe (28) is fixedly connected to the inner wall of the combustion chamber (25). The end of the first exhaust pipe (28) away from the combustion chamber (25) passes through the inner wall of the mounting plate (1). The end of the first exhaust pipe (28) away from the combustion chamber (25) is located above the mounting plate (1).

9. The apparatus for preparing graphene composite films with wave-absorbing function according to claim 8, characterized in that, The air inlet pipe (6) is fixed to a preheating box (29) at one end away from the box body (2). The bottom of the preheating box (29) is fixedly connected to a first exhaust pipe (28), and the top side of the preheating box (29) is fixedly connected to a second exhaust pipe (30). The upper part of the preheating box (29) is fitted on the outer wall of the first air inlet pipe (16), and the lower part of the preheating box (29) is fitted on the outer wall of the second air inlet pipe (22).

10. The apparatus for preparing graphene composite films with wave-absorbing function according to claim 9, characterized in that, A purification box (31) is fixed on the top of the mounting plate (1). The end of the second exhaust pipe (30) away from the preheating box (29) passes through the top of the purification box (31) and enters the interior of the purification box (31). The interior of the purification box (31) contains purification liquid. The exhaust end of the second exhaust pipe (30) is located inside the purification liquid. A discharge pipe is fixedly connected to one side of the top of the purification box (31).

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