Integrated equipment and method for simultaneously preparing graphene and silicon carbide nanowire by using flash Joule thermal method

Abstract

The invention discloses an integrated device and method for simultaneously preparing graphene and silicon carbide nanowires through a flash evaporation Joule thermal method. Comprising a vacuum system, a detection system, a central control system, a discharge system, a heating pipe, a reaction pipe and a deposition pipe. The vacuum system provides a vacuum environment and fixes a reaction sample; the detection system monitors reaction data and transmits the data to the central control system; the central control system receives and records reaction data, controls discharging parameters and sends a charging and discharging command; the discharging system receives the charging and discharging command to discharge the heating pipe; the heating tube performs discharge reaction, current generates joule heat through a conductive carbon source in the tube, and heat is transferred into the reaction tube and the deposition tube through heat transfer; the reaction tube absorbs heat to heat a mixed carbon source and a silicon source stored in the reaction tube, and the top of the reaction tube is provided with a row of small circular-truncated-cone-shaped holes communicated with the deposition tube; the deposition tube collects reaction tube gas, and the tube wall is coated with a catalyst for reactant deposition and growth. The method is suitable for simultaneously preparing the graphene and the silicon carbide nanowire.

Description

Technical Field

[0001] The invention belongs to the field of composite material manufacturing, and particularly relates to an integrated device and method for simultaneously preparing graphene and silicon carbide nanowires by a flash evaporation Joule heat method. Background Art

[0002] Graphene is a material with a two-dimensional honeycomb lattice structure composed of carbon atoms in sp2 hybrid orbitals. It has excellent electrical conductivity, thermal conductivity, piezoelectric properties and optical properties. Common methods for preparing graphene include mechanical exfoliation, chemical vapor deposition, chemical reduction, etc. Among them, the mechanical exfoliation method has low yield, it is difficult to prepare large-area graphene, and the exfoliated graphite lacks uniformity; the chemical vapor deposition method has high equipment cost and operation requirements and is not suitable for large-scale production; the chemical reduction method usually has more structural defects, and there is also the problem of residual reducing agent contaminating the material.

[0003] Silicon carbide is a wide bandgap semiconductor composed of silicon and carbon. It has high covalent bond energy and a stable structure. One-dimensional silicon carbide nanomaterials have unique physical and chemical properties, excellent mechanical properties and high electrical conductivity. Common methods for preparing silicon carbide nanowires include carbon thermal reduction, chemical vapor deposition, electrospinning, sol-gel, etc. Among them, the carbon thermal reduction process involves multiple reactions, the production process is complicated, and it cannot be mass-produced; the chemical vapor deposition method requires precise control of temperature and pressure, the required equipment is expensive, and the deposition speed is slow; the electrospinning method has low production efficiency and complex equipment; the sol-gel method requires relatively expensive precursors and catalysts, and also requires complex post-processing, which is costly and has a great impact on the environment.

[0004] At present, most of the methods for preparing graphene and silicon carbide nanowires are in the laboratory stage, with low efficiency and high cost. There are still many challenges in realizing the industrial production of graphene and silicon carbide nanowires. Flash Joule heating technology is a new material preparation technology that can instantly heat the material to an extremely high temperature (up to 3000K or more) and can prepare high-quality, low-defect graphene. At the same time, this rapid heating and cooling process also helps to form silicon carbide nanowires. Compared with traditional heating methods, the equipment required for flash Joule heating technology is relatively simple and the maintenance cost is low; the heating process can be precisely controlled by current regulation, which is convenient for automation and intelligence; no exhaust gas or other harmful emissions are generated, which is more in line with environmental protection requirements. However, the existing flash Joule heating technology only focuses on the preparation of a single product. In the actual process, a large amount of energy is dissipated by thermal radiation, and there are certain requirements for the conductivity of the material. Non-highly conductive materials need to introduce conductive additives or substrates, which leads to impurities and difficulty in obtaining independent products. At present, the preparation of nanomaterials such as graphene by flash Joule heating has the problem of low energy utilization, and it is difficult to meet specific conductivity requirements for the preparation of nanomaterials with non-high conductive precursors such as silicon carbide nanowires. Therefore, it is of great significance to study a synthesis process for nanomaterials with high energy utilization, high production efficiency and adaptability to a variety of non-high conductive precursors. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention proposes an integrated device and method for simultaneously preparing graphene and silicon carbide nanowires by the flash Joule heating method, which can be adapted to the processes of various nanomaterials that are not high-conductive precursors, and can simultaneously prepare high-quality, low-defect graphene and silicon carbide nanowires without the need for long-term high-temperature heating, thereby meeting the production requirements of high efficiency, low cost and easy scalability.

[0006] The present invention is achieved through the following technical solutions:

[0007] An integrated device and method for simultaneously preparing graphene and silicon carbide nanowires by flash Joule heating method, comprising a vacuum system, a detection system, a central control system, a discharge system, a heating tube, a reaction tube, and a deposition tube;

[0008] The vacuum system includes a fixing device, a vacuum box, and a vacuum pump; the fixing device is used to fix the heating tube, the reaction tube, the deposition tube, and the electrode in the vacuum box, and the vacuum box is connected to the vacuum pump, and the air in the vacuum box is extracted by the vacuum pump;

[0009] The detection system includes a vacuum pressure gauge, an infrared thermometer, and a circuit monitoring device; the vacuum pressure gauge is connected to the vacuum box to measure the air pressure value in the vacuum box, the infrared thermometer is connected to the vacuum box to measure the temperature in the heating tube, the reaction tube and the deposition tube, and the circuit monitoring device measures the voltage, current and resistance at both ends of the conductive carbon source in the heating tube. The detection system monitors the reaction data and transmits it to the central control system through electrical signals;

[0010] The central control system plays the role of command transmission and data processing in the entire equipment, connecting the detection system and the discharge system; the central control system selects appropriate discharge parameters according to the resistance data transmitted by the receiving circuit monitoring device, and transmits charge and discharge commands to the discharge system. When the discharge system is discharging, the central control system receives the temperature data of the infrared thermometer and the real-time voltage and current data of the circuit monitoring device, and promptly makes corresponding feedback to adjust the new discharge parameters and transmit the charge and discharge commands. After the discharge is completed, the detection system response data is recorded and sorted out;

[0011] The discharge system includes an inductor, a charging device, and electrodes; the inductor receives instructions from the central control system and controls the rapid closing of the circuit switch to control the charging and discharging time and voltage of the charging device. The charging device is composed of a capacitor and is used to store and release electrical energy. The charging device is connected to the electrode, which is made of pure copper and has threads. It can be fixed to the fixing device through a nut and clamps the conductive carbon source in the heating tube at the same time. The resistance is controlled by the degree of clamping.

[0012] The heating tube is made of quartz and contains a conductive carbon source. When the discharge system discharges, the current passes through the conductive carbon source to generate Joule heat, and the heat is transferred to the reaction tube and the deposition tube through heat transfer;

[0013] The reaction tube is made of quartz, with conductive plugs installed on both sides of the tube mouth. The conductive plugs are made of pure copper and connected to electrodes, which have auxiliary Joule heating effect on the mixed carbon source and silicon source in the tube. There is a row of several truncated cone-shaped small holes just above the tube wall. The reactants in the tube react and sublimate into gaseous state under the heat, and enter the deposition tube through the small holes for deposition;

[0014] The deposition tube is made of quartz, with insulating plugs installed on both sides of the tube mouth. The insulating plugs are made of glass fiber and are used to fix the reaction tube and the deposition tube and prevent the reaction gas from escaping. The tube wall is coated with a catalyst. After the reaction product gas enters the deposition tube, it adheres to the tube wall and is deposited to generate a product.

[0015] An integrated device and method for simultaneously preparing graphene and silicon carbide nanowires by flash Joule heating method, comprising the following steps:

[0016] Step 1: Select a suitable conductive carbon source, pre-treat the conductive carbon source, make it into powder, fill it into the heating tube, and press it through the electrode;

[0017] Step 2: Select appropriate carbon source and silicon source, pre-treat them, make them into powder, mix them evenly in a fixed ratio and fill them into the lower half of the reaction tube, ensure that the small hole in the reaction tube wall is located directly above, and insert conductive plugs and insulating plugs to seal the reaction tube and deposition tube respectively;

[0018] Step 3: Fix the heating tube, reaction tube and deposition tube to the fixture through electrodes, measure the resistance at both ends of the electrodes through the circuit monitoring device, set appropriate discharge parameters through the central control system, place the fixture in the vacuum box and under the infrared thermometer, close the vacuum box door and valve, and control the discharge system to charge;

[0019] Step 4: Open the valve and power switch of the vacuum pump to perform vacuum operation, observe the reading of the vacuum pressure gauge on the vacuum box, and close the valve and power switch of the vacuum pump after the air pressure value reaches the required range;

[0020] Step 5: The central control system transmits a discharge command to the discharge system, firstly performs a short-time high-voltage discharge on the heating tube, and then performs an intermittent short-time low-voltage discharge on the heating tube;

[0021] Step 6: During the discharge process, the infrared thermometer of the detection system records the temperature distribution at the heat source in real time, records the measurement situation in real time and transmits it to the central control system. The central control system monitors the reaction temperature in real time and gives corresponding feedback: when it is detected that the temperature at the heat source position does not reach the reaction interval, it outputs instructions to the discharge system to increase the discharge voltage; when it is detected that the temperature exceeds the reaction interval, it reduces the discharge voltage to make the temperature at the heat source position return to the set interval;

[0022] Step 7: The central control system records and organizes the reaction data of the detection system, observes the reaction situation through the observation port of the vacuum box door, and repeats step 5 according to the situation;

[0023] Step 8: Open the vacuum box valve to complete the pressure relief, open the vacuum box door, remove the heating tube and the reaction tube through the slide rail separation fixture bracket, collect the product in the deposition tube, remove the conductive plug and the insulating plug, and collect the product in the reaction tube.

[0024] The present invention has at least the following advantages and effects over the prior art:

[0025] The present invention utilizes the principle of Joule heating to heat, can raise the temperature to the reaction temperature in a short time, and has high thermal efficiency, can achieve uniform heating while reducing heat loss during conduction;

[0026] The present invention solves the problem that it is inconvenient to use Joule heating technology for non-high-conductivity precursors by separating the heating zone and the reaction zone, and can prepare two different nanomaterials at the same time;

[0027] The present invention uses a layered tube design to allow the reaction product to grow in the deposition area. Compared with the traditional vapor deposition method, it has low equipment requirements, does not require long-term high-temperature heating, and has low energy consumption costs;

[0028] The present invention has the characteristics of simple structure and easy manufacturing. It can be modified at a low cost as needed to replace raw materials to prepare other nanomaterials. At the same time, the technical means are simple and easy to operate, and the operation is simple and suitable for automation and scale. Compared with the existing technology, it has outstanding substantial progress. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of an integrated device for simultaneously preparing graphene and silicon carbide nanowires by flash Joule heating method;

[0030] Figure 1 The numbers represent: 1-vacuum system; 2-detection system; 3-central control system; 4-discharge system; 5-heating tube; 6-reaction tube; 7-deposition tube; 1-1-fixing device; 1-2-vacuum box; 1-3-vacuum pump; 2-1-vacuum pressure gauge; 2-2-infrared thermometer; 2-3-circuit monitoring device.

[0031] Figure 2 The present invention is a process flow chart of an integrated device and method for simultaneously preparing graphene and silicon carbide nanowires by a flash joule heat method.

[0032] Figure 3 is a circuit diagram of the discharge system 4;

[0033] Figure 3 The numbers in the figure indicate: 4-1-inductor; 4-2-charging device; 4-3-electrode.

[0034] Figure 4 It is a schematic diagram of the structure of the heating tube 5, the reaction tube 6, the deposition tube 7, and the electrode 4-3; in the figure, the washer 1-1-1, the spring 1-1-2, the nut 1-1-3, the conductive plug 1-1-4, and the insulating plug 1-1-5 belong to the fixing device 1-1;

[0035] Figure 4 The numbers in the figure represent: 5-heating tube; 6-reaction tube; 7-deposition tube; 1-1-1-washer; 1-1-2-spring; 1-1-3-nut; 1-1-4-conductive plug; 1-1-5-insulating plug; 4-3-electrode; 6-1-several truncated cone-shaped holes. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0037] Example

[0038] like Figure 1 As shown, the present invention discloses an integrated device and method for simultaneously preparing graphene and silicon carbide nanowires by flash Joule heat method, comprising a vacuum system 1, a detection system 2, a central control system 3, a discharge system 4, a heating tube 5, a reaction tube 6, and a deposition tube 7;

[0039] The vacuum system 1 includes a fixing device 1-1, a vacuum box 1-2, and a vacuum pump 1-3; the fixing device is used to fix the heating tube 5, the reaction tube 6, the deposition tube 7 and the electrode 4-3 in the vacuum box, and the vacuum box is connected to the vacuum pump to extract the air in the vacuum box through the vacuum pump;

[0040] The detection system 2 includes a vacuum pressure gauge 2-1, an infrared thermometer 2-2, and a circuit monitoring device 2-3; the vacuum pressure gauge is connected to the vacuum box 1-2 to measure the air pressure value in the vacuum box, the infrared thermometer is connected to the vacuum box to measure the temperature in the heating tube 5, the reaction tube 6 and the deposition tube 7, the circuit monitoring device measures the voltage, current and resistance at both ends of the conductive carbon source in the heating tube, and the detection system monitors the reaction data and transmits it to the central control system 3 through electrical signals;

[0041] The central control system 3 plays the role of command transmission and data processing in the entire device, and is connected to the detection system 2 and the discharge system 4; the central control system selects appropriate discharge parameters according to the resistance data transmitted by the receiving circuit monitoring device 2-3, and transmits charge and discharge commands to the discharge system. When the discharge system is discharging, the central control system receives the temperature data of the infrared thermometer 2-2 and the real-time voltage and current data of the circuit monitoring device, and promptly makes corresponding feedback to adjust the new discharge parameters and transmit the charge and discharge commands. After the discharge is completed, the detection system response data is recorded and sorted out;

[0042] The discharge system 4 includes an inductor 4-1, a charging device 4-2, and an electrode 4-3; the inductor receives instructions from the central control system 3, controls the rapid closing of the circuit switch to control the charging and discharging time and voltage of the charging device, the charging device is composed of a capacitor, and is used to store and release electrical energy, the charging device is connected to the electrode, the electrode is made of pure copper, has threads, and can be fixed to the fixing device 1-1 through a nut 1-1-3, and at the same time clamps the conductive carbon source in the heating tube 5, and controls the resistance by the degree of clamping;

[0043] The heating tube 5 is made of quartz, and a conductive carbon source is installed in the tube. When the discharge system 4 discharges, the current passes through the conductive carbon source to generate Joule heat, and the heat is transferred to the reaction tube 6 and the deposition tube 7 through heat transfer;

[0044] The reaction tube 6 is made of quartz, and conductive plugs 1-1-4 are installed on both sides of the tube mouth. The conductive plugs are made of pure copper and connected to the electrodes 4-3, which have an auxiliary Joule heating effect on the mixed carbon source and silicon source in the tube. There is a row of several truncated cone-shaped small holes 6-1 just above the tube wall. The reactants in the tube react and sublimate into silicon carbide gas under heat, and enter the deposition tube 7 through the small holes for deposition;

[0045] The deposition tube 7 is made of quartz, and insulating plugs 1-1-5 are installed on both sides of the tube mouth. The insulating plugs are made of glass fiber and are used to fix the reaction tube 6 and the deposition tube and prevent the reaction gas from escaping. The tube wall is coated with a catalyst. After the reaction product gas enters the deposition tube, it adheres to the tube wall and deposits to generate products.

[0046] A specific process of an integrated device and method for simultaneously preparing graphene and silicon carbide nanowires by flash Joule heat method includes the following steps:

[0047] Step 1: Select carbon black as the conductive carbon source, heat and dry the carbon black to make it into powder, record it as material A, take 1g of material A and fill it into the heating tube, and press it through the electrode;

[0048] Step 2: Select carbon nanotubes as the carbon source and silicon powder as the silicon source, take 1g of carbon nanotubes and 4g of silicon powder, add them into 100g of distilled water and stir for 30min, put them into an oven at 140℃ and dry them for 6h, then take them out and make them into powder, which is recorded as material B. Take 1.5g of material B and fill it into the lower half layer of the reaction tube, ensuring that the small hole in the wall of the reaction tube is located directly above, and plug in the conductive plug and the insulating plug to seal the reaction tube and the deposition tube respectively;

[0049] Step 3: Fix the heating tube, reaction tube and deposition tube to the fixture through electrodes, measure the resistance at both ends of the electrodes at 8±0.5Ω through the circuit detection system, set the high voltage 160V discharge time to 0.5s, set the low voltage 120V discharge time to 50ms, the discharge cycle to 0.1s, and the discharge times to 5 times, place the fixture in the vacuum box and under the infrared thermometer, close the vacuum box door and valve, and control the discharge system to charge;

[0050] Step 4: Open the valve and power switch of the vacuum pump to perform vacuum operation, observe the indication of the vacuum pressure gauge on the vacuum box, and close the valve and power switch of the vacuum pump after the air pressure reaches a vacuum degree of 0.1MPa;

[0051] Step 5: The central control system transmits a discharge command to the discharge system, firstly performs a short-time high-voltage discharge on the heating tube, and then performs an intermittent short-time low-voltage discharge on the heating tube;

[0052] Step 6: During the discharge process, the infrared thermometer of the detection system records the temperature distribution at the heat source in real time, records the measurement situation in real time and transmits it to the central control system. The central control system monitors the reaction temperature in real time and gives corresponding feedback: when it is detected that the temperature in the heating tube does not reach 2700±100℃, and the reaction tube and deposition tube do not reach 1400±100℃, it outputs instructions to the discharge system to increase the 5V discharge voltage. When it is detected that the temperature exceeds the reaction range, the 5V discharge voltage is reduced to make the temperature at the heat source position return to the set range;

[0053] Step 7: The central control system records and organizes the reaction data of the detection system, and observes the reaction through the observation port of the vacuum box door. If there is less product in the deposition tube, repeat step 5;

[0054] Step 8: Open the vacuum box valve to complete the pressure relief, open the vacuum box door, remove the heating tube and the reaction tube through the slide rail separation fixture bracket, collect the B material product in the deposition tube, remove the conductive plug and the insulating plug, and collect the A material product in the reaction tube.

[0055] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An integrated device and method for simultaneously preparing graphene and silicon carbide nanowires by flash Joule heating, characterized in that: Including vacuum system, detection system, central control system, discharge system, heating tube, reaction tube, deposition tube; The vacuum system includes a fixing device, a vacuum box, and a vacuum pump; the fixing device is used to fix the heating tube, the reaction tube, the deposition tube, and the electrode in the vacuum box, and the vacuum box is connected to the vacuum pump, and the air in the vacuum box is extracted by the vacuum pump; The detection system includes a vacuum pressure gauge, an infrared thermometer, and a circuit monitoring device; the vacuum pressure gauge is connected to a vacuum box to measure the air pressure value in the vacuum box, the infrared thermometer is connected to the vacuum box to measure the temperature in the heating tube, the reaction tube, and the deposition tube, the circuit monitoring device measures the voltage, current, and resistance at both ends of the conductive carbon source in the heating tube, and the detection system monitors the reaction data and transmits it to the central control system through electrical signals; The central control system plays the role of command transmission and data processing in the entire device, connecting the detection system and the discharge system; the central control system selects appropriate discharge parameters according to the resistance data transmitted by the receiving circuit monitoring device, and transmits charge and discharge commands to the discharge system. When the discharge system is discharging, the central control system receives the temperature data of the infrared thermometer and the real-time voltage and current data of the circuit monitoring device, and promptly makes corresponding feedback to adjust the new discharge parameters and transmit the charge and discharge commands. After the discharge is completed, the detection system response data is recorded and sorted out; The discharge system includes an inductor, a charging device, and electrodes; the inductor receives instructions from the central control system and controls the rapid closing of the circuit switch to control the charging and discharging time and voltage of the charging device. The charging device is composed of a capacitor and is used to store and release electrical energy. The charging device is connected to the electrode, which is made of pure copper and has threads. It can be fixed to the fixing device through a nut and clamps the conductive carbon source in the heating tube at the same time, and the resistance is controlled by the degree of clamping; The heating tube is made of quartz, and a conductive carbon source is installed in the tube. When the discharge system discharges, the current passes through the conductive carbon source to generate Joule heat, and the heat is transferred to the reaction tube and the deposition tube through heat transfer; The reaction tube is made of quartz, and conductive plugs are installed on both sides of the tube mouth. The conductive plugs are made of pure copper and connected to electrodes, which have an auxiliary Joule heating effect on the mixed carbon source and silicon source in the tube. A row of several truncated cone-shaped small holes are opened just above the tube wall. The reactants in the tube react and sublimate into gaseous state under heat, and enter the deposition tube through the small holes for deposition; The deposition tube is made of quartz, and insulating plugs are installed on both sides of the tube mouth. The insulating plugs are made of glass fiber and are used to fix the reaction tube and the deposition tube and prevent the reaction gas from escaping. The tube wall is coated with a catalyst. After the reaction product gas enters the deposition tube, it adheres to the tube wall and deposits to generate products.

2. The integrated device and method for simultaneously preparing graphene and silicon carbide nanowires by flash Joule heating method according to claim 1, characterized in that: The central control system controls the charge and discharge time of the discharge system through wires, firstly performs a short-time high-voltage discharge on the heating tube to convert the conductive carbon source in the tube into graphene, and heats the reaction tube and the deposition tube at the same time, and then performs an intermittent short-time low-voltage discharge on the heating tube to heat the mixed carbon source and silicon source in the reaction tube and convert them into gas-phase silicon carbide.

3. The integrated device and method for simultaneously preparing graphene and silicon carbide nanowires by flash Joule heating method according to claim 1, characterized in that: Conductive plugs are installed on both sides of the reaction tube mouth. The conductive plugs and the mixed carbon source and silicon source in the tube form a circuit connection electrode. The current passes through to form auxiliary Joule heating. There is a row of small holes just above the tube wall. The small holes are truncated cone-shaped and play a reflux role. The reactants in the tube react and sublimate into silicon carbide gas under the heat, and enter the deposition tube through the small holes for deposition.

4. The integrated device and method for simultaneously preparing graphene and silicon carbide nanowires by flash Joule heating method according to claim 1, characterized in that: The inner side of the wall of the deposition tube is coated with a metal catalyst, which has the function of catalyzing the growth of silicon carbide nanowires.

5. An integrated device and method for simultaneously preparing graphene and silicon carbide nanowires by flash Joule heating, characterized in that Use the following steps: Step 1: Select a suitable conductive carbon source, pre-treat the conductive carbon source, make it into powder, fill it into the heating tube, and press it through the electrode; Step 2: Select appropriate carbon source and silicon source, pre-treat them, make them into powder, mix them evenly in a fixed ratio and fill them into the lower half of the reaction tube, ensure that the small hole in the reaction tube wall is located directly above, and insert conductive plugs and insulating plugs to seal the reaction tube and deposition tube respectively; Step 3: Fix the heating tube, reaction tube and deposition tube to the fixture through electrodes, measure the resistance at both ends of the electrodes through the circuit monitoring device, set appropriate discharge parameters through the central control system, place the fixture in the vacuum box and under the infrared thermometer, close the vacuum box door and valve, and control the discharge system to charge; Step 4: Open the valve and power switch of the vacuum pump to perform vacuum operation, observe the reading of the vacuum pressure gauge on the vacuum box, and close the valve and power switch of the vacuum pump after the air pressure value reaches the required range; Step 5: The central control system transmits a discharge command to the discharge system, firstly performs a short-time high-voltage discharge on the heating tube, and then performs an intermittent short-time low-voltage discharge on the heating tube; Step 6: During the discharge process, the infrared thermometer of the detection system records the temperature distribution at the heat source in real time, records the measurement situation in real time and transmits it to the central control system. The central control system monitors the reaction temperature in real time and gives corresponding feedback: when it is detected that the temperature at the heat source position does not reach the reaction interval, it outputs instructions to the discharge system to increase the discharge voltage; when it is detected that the temperature exceeds the reaction interval, it reduces the discharge voltage to make the temperature at the heat source position return to the set interval; Step 7: The central control system records and organizes the reaction data of the detection system, observes the reaction situation through the observation port of the vacuum box door, and repeats step 5 according to the situation; Step 8; Open the vacuum box valve to complete pressure relief, open the vacuum box door, remove the heating tube and the reaction tube through the slide rail separation fixture bracket, collect the product in the deposition tube, remove the conductive plug and the insulating plug, and collect the product in the reaction tube.

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