A pretreatment device for preparing graphene powder based on thermal reduction method

Abstract

The utility model relates to drying equipment technical field, concretely is a kind of pretreatment equipment based on preparation of graphene powder of thermal reduction method, the equipment includes outer shell, inner bag and tray, the outer shell tail is equipped with back cover, outer shell front end is equipped with box door, inside is provided with heat insulating plate, left side is provided with handle support, top is provided with through hole two, bottom inner wall is provided with cylindrical sleeve ring, the cylindrical sleeve ring is installed weight sensor, for real-time monitoring the weight change of raw material graphene oxide particle;Inner bag is located in the inside of outer shell, top is provided with through hole one, inner bag inner wall left and right sides are provided with the symmetrical supporting plate of graphene oxide, inner bag bottom is provided with cylindrical support block, the cylindrical support block, located in the four corners of inner bag bottom, cylindrical support block lower end is provided with cylindrical boss and weight sensor contact real-time acquisition and pre-treatment graphene oxide weight change.The device can realize the efficient and high-quality drying pretreatment of graphene oxide particle raw material, saves manpower and energy consumption.

Description

Technical Field

[0001] This invention relates to the field of drying equipment technology, specifically to a pretreatment device for preparing graphene powder based on the thermal reduction method. Background Technology

[0002] Graphene is a novel two-dimensional carbon material of the 21st century, widely used in automotive, energy, medical, and daily life fields due to its excellent electrical and thermal conductivity and superb mechanical properties. Currently, the common method for the industrial production of graphene powder is to use a high-temperature thermal reduction method to eliminate oxygen-containing functional groups on the surface of graphene oxide (GO) particles and repair its planar structure, thereby obtaining graphene. Graphene oxide is mostly prepared using a modified Hummers process, which employs strong acids and strong oxidants to exfoliate and intercalate graphite, producing a graphene oxide slurry. After pressure filtration, a graphene oxide cake is obtained, which is then processed into graphene oxide particles using granulation equipment. These particles are then heat-treated in an expansion furnace and a carbonization furnace to obtain graphene powder. However, graphene oxide particles have a high water content (greater than 50%) and strong acidity. If they are directly expanded, the internal moisture will rapidly vaporize at high temperatures, causing the particles to react violently and carry out a large amount of acidic substances such as sulfides. Therefore, before the high-temperature thermal reduction of GO particles, it is necessary to dry the GO particles to remove most of the moisture and acidic substances.

[0003] Traditional graphene oxide drying methods employ an open-loop model of "static weighing and fixed time," meaning that the material is manually weighed before and after drying, and the mass change is calculated. This process has significant drawbacks. This method cannot monitor the material's state in real time during drying, forcing the drying time to rely solely on empirical presets and lacking objective data. Because different batches of material have varying initial moisture content and weight, this fixed drying time is difficult to precisely adapt, easily leading to under-drying or over-drying. Both under-drying and over-drying reduce production efficiency and quality, and waste energy. Utility Model Content

[0004] Based on the above, this utility model provides a pretreatment device for preparing graphene powder based on the thermal reduction method, which can monitor the weight change of graphene oxide (GO) particles in real time, and solves the problems mentioned in the background art. This device can improve the drying quality and efficiency of graphene oxide particles and save energy.

[0005] A pretreatment device for preparing graphene powder based on thermal reduction includes an outer shell, an inner liner, and a tray. The outer shell is equipped with a rear cover plate at the rear, a door at the front, a heat insulation plate inside, and a handle support on the left side.

[0006] Furthermore, a fan plate is provided at the front end of the rear cover plate, a motor and guide rail are mounted on the fan plate, a fan is mounted on the motor, an inner liner cover plate is installed at the front end of the fan plate, a support plate and a heating tube are installed on the inner liner cover plate, a locking handle is installed on the left side of the box door, which is used to cooperate with the handle support on the left side of the outer shell to close the box door tightly, a sealing ring is installed on the inside of the box door to achieve a sealing effect when closed, and an observation window is provided in the center of the box door to observe the material status in real time.

[0007] Furthermore, the inner liner is located inside the outer shell, with a through-hole at the top. Symmetrical support plates are installed on the left and right sides of the inner wall of the inner liner, with a total of five sets of these plates. Cylindrical support blocks, made of heat-insulating material, are connected to the four corners of the bottom of the inner liner. Their core function is to block heat transfer from the inner liner to the weight sensors at the bottom. Cylindrical protrusions at their lower ends are used to achieve physical contact and force transmission with the weight sensors while ensuring thermal isolation. The signals output by the four weight sensors are transmitted to the control unit. The control unit calculates the weight change rate transmitted by each sensor and takes the average as the judgment standard. When the system determines that the weight change rate is less than a preset threshold of 1% for 30 consecutive minutes, the control unit issues a control command: this command drives an intermediate relay to cut off the power supply circuit between the heating element and the fan motor, and simultaneously triggers a buzzer alarm.

[0008] Furthermore, the inner liner cover is bolted to the mounting plate of the outer shell and does not contact the inner liner. The inner liner is an independent structure and does not directly contact the outer shell. The inner liner cover has a square hole II in the center and two round holes above the square hole II.

[0009] Furthermore, cylindrical collars are provided at the four inner corners of the bottom of the outer casing. These cylindrical collars are connected to the outer casing by welding, and four threaded holes are provided at the bottom end of the cylindrical collars.

[0010] Furthermore, a heat insulation plate is connected to the inner wall of the outer shell, positioned at the upper end of the cylindrical collar, thus forming a thermal barrier between the bottom of the inner liner and the outer shell. A circular hole three on the heat insulation plate is coaxial with the cylindrical collar, allowing the cylindrical support block at the bottom of the inner liner to pass through, without contacting each other. A through hole two is opened at the top of the outer shell, coaxial with the through hole. Threaded holes are provided at the four corners of the back, and a mounting plate is provided on the inner side of the back. The mounting plate has a square hole in the center and threaded holes at the four corners, welded to the inner side of the rear of the outer shell.

[0011] Furthermore, the fan plate is located on the inner side of the back of the outer casing and is connected to the mounting plate. The fan plate has a square hole in the center, through which the motor body passes and is mounted in the center of the fan plate. The fan is mounted on the motor shaft, and a guide rail is mounted below the motor.

[0012] Furthermore, the support plate is located at the upper end of the inner liner cover plate near the inner liner, and the support plate is provided with mounting holes; the upper end of the heating tube passes through the mounting holes and is fixed to the support plate.

[0013] Furthermore, the threaded holes of the fan plate and the inner liner cover are coaxial and are connected together to the mounting plate on the back of the inner liner.

[0014] Furthermore, the tray is drawer-shaped, with a threaded hole near the door, located inside the inner liner, and placed on the pallet.

[0015] The advantages of this utility model are: This invention uses weight sensors integrated into the bottom of the chamber to monitor the weight change rate of graphene oxide (GO) particles in real time during the drying process. Four sets of weight sensors transmit data to the control unit, which calculates the weight change rate of each sensor and takes the average as the judgment standard. The control unit makes an intelligent judgment based on a preset weight change rate threshold. If the weight change rate of the graphene oxide (GO) particles is less than 1% within 30 minutes, the GO particles are considered to have reached the dry state. Once the drying requirement is met, the system automatically executes a shutdown procedure: cutting off the power to the heating element and fan, and triggering a buzzer alarm, thus achieving precise and automatic control of the drying process. This equipment has the following advantages: Improving drying efficiency and calculating the weight change rate in real time allows for accurate judgment of the material's drying status, avoiding resource waste and reduced production efficiency caused by over-drying or under-drying. This ensures that the moisture content of each batch of graphene oxide particles is consistent after drying, resulting in stable and reliable product quality.

[0016] Energy saving: The system immediately cuts off the power to the heating element and fan after determining that drying is complete. Compared with the fixed-duration drying mode, it effectively avoids ineffective energy consumption and significantly reduces production costs.

[0017] To improve product quality, the entire drying process requires no manual intervention or experience-based judgment. It automatically completes the entire process of heating, blowing, monitoring, judgment, and shutdown alarm, which not only reduces the labor intensity and skill requirements of operators, but also avoids quality problems caused by uneven drying.

[0018] Increased production efficiency and precise control ensured optimal equipment operating time, avoiding rework due to insufficient drying or wasted time due to over-drying, thus accelerating the turnover of GO pellets and improving overall production efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0020] Figure 2 This is a schematic diagram of the internal structure of this utility model.

[0021] Figure 3 This is a schematic diagram of the heating element assembly structure.

[0022] Figure 4 This is a schematic diagram of the second-view structure of the present invention.

[0023] Figure 5 This is a schematic diagram of the fan plate assembly structure.

[0024] Figure 6 This is a schematic diagram of the outer shell structure.

[0025] Figure 7 This is a schematic diagram of the inner liner structure.

[0026] Figure 8 This is a schematic diagram of the pallet structure.

[0027] Figure 9 This is a schematic diagram of the third-view structure of this utility model.

[0028] The attached figures are labeled as follows: 1—Outer shell; 11—Through hole two; 12—Mounting plate; 13—Heat insulation plate; 14 – Cylindrical collar; 15 – Handle support; 16 – Three round holes; 2 – Inner liner; 21 – Through hole one; 22 – Support plate; 23 – Cylindrical support block; 3 – Tray; 4 – Inner liner cover; 42 – Support plate; 43 – Square hole two; 5 – Fan plate; 51 – Fan; 52 – Protective cover; 53 – Motor; 54 – Guide rail; 44 – Round hole one; 55 – Round hole two; 7 – Heating element; 8 – Door; 9 – Locking handle; 10 – Rear cover. Detailed Implementation

[0029] See appendix below Figure 1-8 The present invention will be described in detail below.

[0030] For examples, see the appendix. Figure 1 To be continued Figure 9 A pretreatment device for preparing graphene powder based on thermal reduction includes an outer shell 1, an inner liner 2, and a tray 3. The outer shell 1 has a rear cover plate 10 at its rear end and a door 8 at its front end. An insulation plate 13 is installed inside the outer shell 1, and a handle support 15 is located on its left side. A locking handle 9 is installed on the left side of the door 8, which engages with the handle support 15 on the left side of the outer shell 1 to close the door 8 tightly. A sealing ring is installed inside the door 8 to achieve a sealing effect when closed.

[0031] Further, refer to the appendix Figure 4-5The rear cover plate 10 has a fan plate 5 at its front end. A motor 53 and a guide rail 54 are mounted on the fan plate 5. The guide rail 54 is used to install electrical equipment such as air switches, leakage current protectors, and wire terminals. A fan 51 is mounted on the motor 53, and a protective cover 52 is installed around the fan 51. The protective cover 52 prevents dust from falling on the fan and concentrates the airflow towards the center of the inner liner 2. The motor 53 is a variable frequency speed control motor, and its speed can be dynamically adjusted by a programmable logic controller (PLC) according to the drying stage. By changing the speed, the fan 51 can generate different air volumes to adapt to the actual drying needs. Furthermore, the PLC sets an upper speed limit to prevent excessive airflow from scattering the graphene oxide particles.

[0032] Further, refer to the appendix Figure 2-4 The fan plate 5 has an inner liner cover 4 installed at its front end. The inner liner cover has a support plate 42 and a heating tube 7 installed on it. The inner liner cover 4 is bolted to the mounting plate 12 and is located at the tail of the inner liner 2. The inner liner cover 4 has a square hole 43 in its center. The support plate 42 is located at the upper end of the inner liner cover 4 near the inner liner 2. The support plate 42 has a mounting hole, and the upper end of the heating tube 7 passes through the mounting hole and is fixed to the support plate 42. Above the square hole 43, a circular hole 44 is provided. The circular hole 44 is the same size as the circular hole 55 on the fan plate and is coaxial. It is used to pass the wire through the circular hole 44 and the circular hole 55 from the rear end of the fan plate 5 to connect with the heating tube 7. The two heating tubes 7 are connected in series. According to the actual size of the equipment, two heating tubes 7 with a power of 1.5kw can be selected to make the temperature of the center area of ​​the inner tank reach more than 100℃, which meets the drying requirements. The wire is made of silicone rubber heat-insulating wire, which has good heat resistance, flexibility and insulation, and can withstand a maximum temperature of 300℃.

[0033] Further, refer to the appendix Figure 2 Appendix Figure 6 and attached Figure 7The inner liner cover 4 and the inner liner 2 are not directly connected. The inner space of the inner liner 2 is the main area for drying graphene oxide particles and is located inside the outer shell 1. The top of the inner liner 2 has a through hole 21. Symmetrical support plates 22 are welded on the left and right sides of the inner wall of the inner liner 2. There are five sets of support plates 22. The bottom of the inner liner 2 is provided with a cylindrical support block 23. The cylindrical support block 23 is connected to the inner liner 2 and is located at the four corners of the bottom of the inner liner. The lower end of the cylindrical support block 23 is provided with a cylindrical boss. The cylindrical support block 23 passes through the three circular holes 16 on the heat insulation plate 13 of the outer shell 1. The heat insulation plate 13 is connected to the bottom of the inner side of the outer shell and is located above the cylindrical collar 14. The cylindrical collar 14 is welded to the four corners of the bottom of the inner side of the outer shell 1. Each cylindrical collar 14 is provided with a threaded hole at the bottom for installing a weight sensor. The weight sensor contacts the cylindrical boss and is used to collect the weight data of the graphene oxide particles in real time. This weight sensor employs a high-temperature strain gauge load cell, capable of withstanding temperatures up to 300℃. It boasts superior overall performance, combining high precision, strong anti-interference capabilities, easy integration, and low cost, making it the preferred sensor for equipment used in drying graphene oxide particles. The cylindrical support block 23, made of heat-insulating ceramic material, serves to block heat transfer from the inner liner to the bottom outer shell and the weight sensor, effectively preventing measurement drift due to overheating. Simultaneously, the heat insulation plate 13, made of ceramic fiber material, constructs a highly efficient thermal barrier between the inner liner 2 and the bottom of the outer shell 1, achieving comprehensive thermal protection for critical components.

[0034] The through hole 21 and through hole 11 are coaxial. Through hole 21 is used to discharge the evaporated gas from the inner liner during the drying process. Through hole 11 is connected to the filter device to discharge the gas generated during the drying of graphene oxide particles in a timely manner and after filtration, it is discharged into the atmosphere after being tested and meeting the requirements, adhering to the production concept of safety and environmental protection.

[0035] Further, refer to the appendix Figure 2 and attached Figure 8 The tray 3 is placed on the tray plate 22 of the inner liner 2. To meet the drying requirements, five sets of tray plates 22 are provided on the inner wall of the inner liner 2, so a maximum of five trays 3 can be placed at a time. The empty trays 3 can also be removed according to the actual production needs, so that the drying speed of the graphene oxide particles is faster. Both the inner liner 2 and the tray 3 are made of 310S stainless steel, which has the advantages of high temperature resistance, corrosion resistance and oxidation resistance, and is the preferred material for manufacturing equipment for drying graphene oxide particles.

[0036] After the moist graphene oxide is placed in tray 3, tray 3 is placed on tray 22 and pushed into inner liner 2. Door 8 is closed and locked with locking handle 9. Then, the equipment switch is turned on, and heating element 7 begins heating. When the temperature preset in the programmable logic controller (PLC) is reached, fan 51 rotates, blowing hot air onto the moist graphene oxide particles. The evaporated gas flows into the filter device through through-hole 21 and through-hole 11. During the drying process, a weight sensor located inside cylindrical collar 14 monitors the weight of GO in real time. This weight sensor outputs an analog voltage signal. This analog signal is first transmitted to the analog input module of the PLC system via a shielded cable. The core function of this module is analog-to-digital (A / D) conversion. It samples and quantizes continuous analog signals, converting them into digital quantities that the PLC central processing unit (CPU) can recognize and process. The PLC CPU reads this digital weight value and calls a preset program to calculate the weight change rate of the material. There are four sets of weight change rates, corresponding to the four sensors, and their average value is used as the judgment standard. This weight change rate is a precise indicator for judging the drying status. If the weight change rate of the graphene oxide (GO) particles is less than 1% within 30 minutes, the GO particles are considered to have reached a dry state. The PLC digital output module will then activate, outputting a digital signal to energize the intermediate relay coil. The relay contacts will then actuate, cutting off the power supply circuit connecting the heating element 7 and the fan motor 53, thus automatically stopping the machine. Simultaneously, another digital output will trigger a buzzer alarm, notifying personnel to remove the tray 3 containing the graphene oxide particles.

[0037] The above content is only a preferred embodiment of this utility model. For those skilled in the art, there will be changes in the specific implementation method, application scope and material selection based on the inventive idea. The content of this specification should not be construed as a limitation of the invention.

Claims

1. A pretreatment device for preparing graphene powder based on thermal reduction method, comprising an outer shell (1), an inner liner (2) disposed inside the outer shell (1), and a tray (3) for holding materials, wherein the outer shell (1) is provided with a door (8) at the front end and a fan (51) driven by a motor (53) and a heating tube (7) at the rear end, characterized in that: The inner liner (2) is independently supported inside the outer shell (1) by four cylindrical support blocks (23) set at its bottom; four weight sensors are correspondingly set on the inner side of the bottom of the outer shell (1), and the sensing end of the weight sensor is in contact with the bottom of the cylindrical support block (23) for real-time monitoring of the weight change of graphene oxide particles; the pretreatment equipment for preparing graphene powder based on thermal reduction method also includes a control unit, which is connected to the weight sensor, motor (53) and heating tube (7) by wires and is configured to: calculate the real-time weight change rate of the material based on the weight data collected by the weight sensor, and automatically cut off the power supply of the heating tube (7) and the motor (53) to stop the drying operation when the weight change rate is lower than a preset threshold, and trigger a buzzer to indicate the end of the process.

2. The pretreatment equipment for preparing graphene powder based on thermal reduction method according to claim 1, characterized in that: The control unit has a preset judgment condition: when the weight change rate of the material is less than 1% within 30 consecutive minutes, the heating tube (7) and the motor (53) are controlled to stop working.

3. The pretreatment equipment for preparing graphene powder based on thermal reduction method according to claim 1, characterized in that: The cylindrical support blocks (23) at the four corners of the bottom of the inner liner (2) are support structures. The lower end of the cylindrical support block (23) is provided with a cylindrical boss. The inner side of the bottom of the outer shell (1) is provided with a cylindrical collar (14). The weight sensor is installed in the cylindrical collar (14). The cylindrical boss is in contact with the sensing end of the weight sensor.

4. The pretreatment equipment for preparing graphene powder based on thermal reduction method according to claim 1, characterized in that: The outer shell (1) is provided with a heat insulation plate (13); the heat insulation plate (13) has a three-circular hole (16) for the cylindrical support block (23) to pass through. The heat insulation plate can block the heat transfer from the inner liner (2) to the bottom of the outer shell (1) and reduce the impact of high temperature on the weight sensor.

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