Microwave thermogravimetric analyzer

Abstract

The utility model relates to the technical field of microwave equipment, in particular to a microwave thermogravimetric analyzer which comprises a support frame, a furnace body is arranged in the support frame, the upper end of the furnace body is connected with a furnace cover, and the lower end of the furnace body is connected with a bottom sealing plate; a resonant cavity is formed by the furnace body, the furnace cover and the inner space of the sealing plate, and a magnetron for emitting microwaves into the resonant cavity is arranged on the furnace body; a weighing module is further arranged on the bottom sealing plate, a supporting rod is connected to the weighing module, and a weighing tray used for containing materials is arranged at the upper end of the supporting rod; the weighing module is integrated at the bottom of the resonant cavity, so that microwave heating and real-time weighing are synchronously carried out, the technical problem that traditional microwave equipment cannot monitor material mass change is solved, and accurate data support is provided for reaction kinetics research; meanwhile, the resonant cavity adopts a split type design, and the furnace body is provided with a furnace cover and a bottom sealing plate, so that the weighing module is convenient to install and maintain.

Description

Technical Field

[0001] This utility model relates to the field of microwave equipment technology, specifically a microwave thermogravimetric analyzer. Background Technology

[0002] Microwave heating equipment is a device that uses microwave electromagnetic fields to induce polarization vibrations in the molecules within materials, thereby achieving rapid heating. A typical microwave heating system mainly consists of a microwave generator (such as a magnetron), a waveguide transmission system, a resonant cavity, and a temperature control system. Due to its rapid heating speed, high thermal efficiency, and selective heating capabilities, this type of equipment is widely used in materials synthesis, food processing, and chemical analysis.

[0003] However, existing microwave heating equipment has significant functional limitations. In many industrial production and scientific research processes, the heating of materials is often accompanied by significant changes in mass. For example, in catalyst preparation, the thermal decomposition of precursors releases gases, leading to a decrease in mass; during the pyrolysis of polymer materials, polymer chain breakage produces volatile components, causing sample weight loss; in the reduction reaction of metal oxides, the removal of oxygen causes a decrease in mass. These heating processes involving mass changes require real-time monitoring of material weight changes to accurately grasp the reaction progress.

[0004] However, existing microwave heating equipment cannot monitor material mass changes in real time, making it impossible to accurately calculate reaction conversion rates, kinetic parameters, or weight loss rates. Therefore, there is an urgent need for a new type of microwave thermogravimetric analyzer that integrates microwave heating and high-precision weighing functions to meet the precise analysis requirements of complex reaction processes. Utility Model Content

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a microwave thermogravimetric analyzer that integrates microwave heating and weighing functions.

[0006] The technical solution adopted by this utility model to solve its technical problem is:

[0007] A microwave thermogravimetric analyzer includes a support frame, a furnace body housed within the support frame, a furnace cover connected to the upper end of the furnace body, and a bottom sealing plate connected to the lower end of the furnace body; the internal space of the furnace body, furnace cover, and bottom sealing plate constitutes a resonant cavity, and a magnetron emitting microwaves into the resonant cavity is mounted on the furnace body; a weighing module is also mounted on the bottom sealing plate, a support rod is connected to the weighing module, and a weighing tray for holding materials is mounted on the upper end of the support rod.

[0008] Compared with the prior art, the outstanding features of this utility model, which adopts the above technical solution, are:

[0009] This new invention integrates the weighing module at the bottom of the resonant cavity, enabling simultaneous microwave heating and real-time weighing. This solves the technical problem that traditional microwave equipment cannot monitor changes in material mass, providing accurate data support for reaction kinetics research. At the same time, the resonant cavity adopts a split design (furnace body plus furnace cover plus bottom sealing plate), which facilitates the installation and maintenance of the weighing module.

[0010] As a preferred embodiment, a further technical solution of this utility model is:

[0011] Preferably, a quartz tube is installed inside the furnace body, and the quartz tube is sealed to the bottom sealing plate and the furnace cover. The internal space of the quartz tube, the bottom sealing plate, and the furnace cover forms a sealed heating chamber. A mounting shell is installed at the bottom of the bottom sealing plate, and a through hole is provided on the bottom sealing plate. The weighing module is installed in the mounting shell, and the support rod passes through the through hole into the quartz tube. An exhaust pipe and a vacuum pipe are connected to the bottom sealing plate. The exhaust pipe is connected to an exhaust valve, and the vacuum pipe is connected to a suction valve. An air inlet pipe is provided on the furnace cover, and the air inlet pipe is connected to an air inlet valve. Through the cooperation of the quartz tube, the vacuum pipe, and the air inlet pipe, a controllable atmosphere environment is achieved to meet the requirements of different reaction conditions.

[0012] Preferably, a first flange connecting plate is provided at the upper end of the furnace body, and a second flange connecting plate is provided at the lower end. The bottom sealing plate is bolted to the furnace body through the second flange connecting plate. A third flange connecting plate is provided at the lower edge of the furnace cover. The side cross-section of the third flange connecting plate is an inverted L-shaped structure. The horizontal connecting plate of the third flange connecting plate is bolted to the first flange connecting plate. An upper connecting ring groove is provided on the inner side of the first flange connecting plate, and a first sealing ring is provided in the upper connecting ring groove. The outer wall of the quartz tube and the lower end of the vertical connecting plate of the third flange connecting plate abut against the first sealing ring. A lower connecting ring groove is provided on the inner side of the second flange connecting plate, and a second sealing ring is provided in the lower connecting ring groove. An annular flange is provided on the bottom sealing plate, and the outer wall of the quartz tube and the upper end of the annular flange abut against the second sealing ring. This achieves double axial sealing of the quartz tube, effectively preventing gas leakage at high temperatures.

[0013] Preferably, the mounting housing includes a side plate and a bottom plate. The upper edge of the side plate is welded and fixed to the bottom sealing plate, and a horizontal connecting plate is provided on the lower edge. A sealing gasket is provided on the bottom plate, and a first through hole for the connecting bolt to pass through is provided on the sealing gasket. The bottom plate is bolted and fixed to the horizontal connecting plate. The mounting housing is easy to disassemble, which facilitates the calibration and maintenance of the weighing module.

[0014] Preferably, a heat insulation pad is provided on the bottom sealing plate, and a second through hole is provided on the heat insulation pad for the support rod to pass through; the heat insulation pad (preferably ceramic fiber material) can block heat conduction above 300°C, reduce the working temperature of the weighing module, and avoid the influence of thermal drift on the measurement accuracy.

[0015] Preferably, a bracket is also provided on the bottom sealing plate, and an insulated box is provided on the bracket. The insulated box is a spliced ​​structure, including a bottom support, a surrounding plate, and a box cover. A third through hole is provided on the bottom support for the support rod to pass through, and the weighing tray is located inside the insulated box. Furthermore, a wave-absorbing coating is provided on the inner wall of the surrounding plate.

[0016] Preferably, the furnace cover includes a lower connecting cylinder and a top cover. The lower end of the lower connecting cylinder is sealed to the upper end of the furnace body, and the air inlet pipe is set on the lower connecting cylinder. A lower hinge seat is provided on one side of the lower connecting cylinder, and an upper hinge seat is provided on the top cover corresponding to the lower hinge seat. The rotating connecting shaft passes through the upper hinge seat and the lower hinge seat from the side and is limited by a limiting nut. The top cover is hinged to the lower connecting cylinder. The hinged top cover design enables one-handed opening and closing operation, improving the convenience of experimental operation.

[0017] Preferably, the furnace cover is also equipped with a quick-locking mechanism, which includes several connecting seats arranged circumferentially on the outer wall of the lower connecting cylinder. Each connecting seat is hinged with a guide rod, and a handwheel is threaded onto the guide rod. The lower end of the handwheel is rotatably connected to a pressing sleeve through a bearing. The pressing sleeve is provided with a locking tooth on the side near the top cover, and the furnace cover is provided with a locking groove that mates with the locking tooth. The quick-locking mechanism can quickly complete the cavity sealing by synchronously pressing at multiple points (3-6 evenly distributed points).

[0018] Preferably, a handle is provided on one side of the top cover. The top cover has a double-layer structure, including an upper cover and a lower cover. The space between the upper cover and the lower cover is a water-cooling cavity. The upper cover is provided with an inlet pipe and an outlet pipe, and also includes a chiller unit. The inlet pipe is connected to the outlet end of the chiller unit, and the outlet pipe is connected to the return end of the chiller unit. The water-cooling cavity design can reduce the surface temperature of the top cover and prevent burns when opening the cover.

[0019] Preferably, a thermocouple for detecting the temperature inside the heating chamber is provided on the top cover.

[0020] Preferably, a pressure gauge for measuring the gas pressure inside the sealed heating chamber is connected to the lower connecting cylinder; the pressure gauge is linked with the vacuum system to achieve closed-loop pressure control, which is particularly suitable for catalytic reaction research that requires a precise gas pressure environment. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the microwave thermogravimetric analyzer in this embodiment of the present invention;

[0022] Figure 2 yes Figure 1 Enlarged structural diagram at point A;

[0023] Figure 3 yes Figure 1 Enlarged structural diagram at point B;

[0024] Figure 4This is a cross-sectional structural schematic diagram of the microwave thermogravimetric analyzer in this embodiment of the present invention;

[0025] Figure 5 yes Figure 4 Enlarged structural diagram at point C;

[0026] Figure 6 This is a cross-sectional view of the insulated box in an embodiment of this utility model;

[0027] Figure 7 This is a cross-sectional view of the microwave thermogravimetric analyzer in this embodiment of the present invention.

[0028] Explanation of reference numerals in the attached drawings: 1. Furnace body; 2. Furnace cover; 201. Lower connecting cylinder; 202. Top cover; 203. Clamping tooth; 3. Bottom sealing plate; 4. Magnetron; 5. Quartz tube; 6. Exhaust pipe; 7. Vacuum tube; 8. Inlet pipe; 9. Thermocouple; 10. Pressure gauge; 11. Insulation box; 1101. Base support; 1102. Enclosure; 1103. Box cover; 12. Casters; 13. Quick-lock mechanism; 1301. Connecting seat; 1302. Guide rod; 1303. Handwheel; 1304. Press-fit sleeve; 1 4. Materials; 15. Cooling fan; 16. Heat dissipation pipe; 17. Weighing module; 18. Support rod; 19. Weighing pallet; 20. Support frame; 21. First flange connecting plate; 22. Third flange connecting plate; 23. Wave-absorbing coating; 24. Second flange connecting plate; 25. Inlet valve; 26. First sealing ring; 27. Annular flange; 28. Second sealing ring; 29. ​​Mounting shell; 2901. Side plate; 2902. Base plate; 30. Upper hinge seat; 31. Lower hinge seat; 32. Rotary connecting shaft. Detailed Implementation

[0029] The present invention will be further described below with reference to specific embodiments. The purpose of this description is only to better understand the content of the present invention. Therefore, the examples given do not limit the scope of protection of the present invention.

[0030] like Figures 1 to 7 As shown, a microwave thermogravimetric analyzer includes a support frame 20, in which a furnace body 1 is disposed. A furnace cover 2 is connected to the upper end of the furnace body 1, and a bottom sealing plate 3 is connected to the lower end. The internal space of the furnace body 1, the furnace cover 2, and the bottom sealing plate 3 forms a resonant cavity. A magnetron 4 that emits microwaves into the resonant cavity is disposed on the furnace body 1. A weighing module 17 is also disposed on the bottom sealing plate 3. A support rod 18 is connected to the weighing module 17, and a weighing tray 19 for holding materials 14 is disposed at the upper end of the support rod 18. Among them, the magnetron 4 is a Samsung OM75P(31)ESGN; the support rod 18 is made of high-purity alumina ceramic material with low thermal conductivity and a temperature resistance of 1500℃, which can effectively block the heat conduction from the furnace body 1 to the weighing module 17.

[0031] This new invention integrates the weighing module 17 at the bottom of the resonant cavity, enabling simultaneous microwave heating and real-time weighing. This solves the technical problem that traditional microwave equipment cannot monitor changes in the mass of material 14, providing accurate data support for reaction kinetics research. At the same time, the resonant cavity adopts a split design (furnace body 1 plus furnace cover 2 plus bottom sealing plate 3), which facilitates the installation and maintenance of the weighing module 17.

[0032] Preferably, a quartz tube 5 is installed inside the furnace body 1, and the quartz tube 5 is sealed to the bottom sealing plate 3 and the furnace cover 2. The internal space of the quartz tube 5, the bottom sealing plate 3, and the furnace cover 2 forms a sealed heating chamber. A mounting shell 29 is provided at the bottom of the bottom sealing plate 3, and a through hole is provided on the bottom sealing plate 3. The weighing module 17 is installed in the mounting shell 29, and the support rod 18 passes through the through hole into the quartz tube 5. An exhaust pipe 6 and a vacuum pipe 7 are connected to the bottom sealing plate 3. The exhaust pipe 6 is connected to an exhaust valve, and the vacuum pipe 7 is connected to an air extraction valve. An air inlet pipe 8 is provided on the furnace cover 2, and the air inlet pipe 8 is connected to an air inlet valve 25.

[0033] This invention achieves heat treatment under vacuum or low pressure by setting up a vacuum tube 7, an air extraction valve, and a heating chamber (composed of a quartz tube 5, a bottom sealing plate 3, and a furnace cover 2), effectively preventing the oxidation of materials 14 or promoting the discharge of volatiles, thus solving the problem of poor vacuum compatibility in traditional microwave ovens. Furthermore, through the cooperation of the air inlet pipe 8, the air inlet valve 25, the exhaust pipe 6, and the exhaust valve, inert gases (such as N2, Ar) or special reaction gases (such as H2, NH3, CH4) can be introduced to meet the needs of specific chemical reactions such as carbonization, nitriding, and reduction, breaking through the limitation of traditional equipment that only supports atmospheric pressure heating.

[0034] like Figures 1 to 3As shown, the furnace body 1 has a first flange connecting plate 21 at the upper end and a second flange connecting plate 24 at the lower end. The bottom sealing plate 3 is bolted to the furnace body 1 through the second flange connecting plate 24. The furnace cover 2 has a third flange connecting plate 22 at the lower edge. The side cross-section of the third flange connecting plate 22 is an inverted L-shaped structure, which serves to connect and seal, effectively preventing microwave leakage. The horizontal connecting plate of the third flange connecting plate 22 is bolted to the first flange connecting plate 21. The inner side of the first flange connecting plate 21 has an upper connecting ring groove, and a first sealing ring 26 is provided in the upper connecting ring groove. The outer wall of the quartz tube 5 and the lower end of the vertical connecting plate of the third flange connecting plate 22 abut against the first sealing ring 26. The inner side of the second flange connecting plate 24 has a lower connecting ring groove, and a second sealing ring 28 is provided in the lower connecting ring groove. The bottom sealing plate 3 has an annular flange 27, and the outer wall of the quartz tube 5 and the upper end of the annular flange 27 abut against the second sealing ring 28. The mounting shell 29 includes a side plate 2901 and a bottom plate 2902. The upper edge of the side plate 2901 is welded and fixed to the bottom sealing plate 3, and a horizontal connecting plate is provided on the lower edge. A sealing gasket is provided on the bottom plate 2902, and a first through hole for the connecting bolts to pass through is provided on the sealing gasket. The bottom plate 2902 is bolted and fixed to the horizontal connecting plate. Through the structure of the first flange connecting plate 21, the second flange connecting plate 24, the side plate 2901, and the bottom plate 2902, the calibration and maintenance of the weighing module 17 are facilitated, as well as the cleaning and maintenance of the inside of the furnace body 1.

[0035] Furthermore, a heat insulation pad is provided on the bottom sealing plate 3, and a second through hole is provided on the heat insulation pad for the support rod 18 to pass through; the heat insulation pad (preferably ceramic fiber material) can block heat conduction above 300°C, reduce the working temperature of the weighing module 17, and avoid the influence of thermal drift on the measurement accuracy.

[0036] In this embodiment, as Figure 4 , Figure 6 The bottom sealing plate 3 is also provided with a bracket, and the bracket is provided with an insulated box 11. The insulated box 11 is a spliced ​​structure, including a bottom support 1101, a surrounding plate 1102, and a box cover 1103. The bottom support 1101 is provided with a third through hole for the support rod 18 to pass through, and the weighing tray 19 is located inside the insulated box 11. Furthermore, the inner wall of the surrounding plate 1102 is also provided with a wave-absorbing coating 23, so that the heat is concentrated inside the insulated box 11, which facilitates the heating of the material 14 inside the insulated box 11.

[0037] This embodiment significantly expands the application range of microwave thermogravimetric analyzers by setting up a modular insulated box 11 with a microwave absorbing coating 23. In particular, it solves the technical bottleneck that low dielectric loss materials (such as Al2O3, SiO2, and some polymer materials) are difficult to directly heat in a microwave field. Its core beneficial effects are reflected in the following aspects: 1. Breaking through the selectivity limitation of microwave heating. For some inert materials (such as ceramic catalyst carriers, quartz sand, etc.), the efficiency of traditional microwave heating is extremely low. In this design, the inner wall of the insulated box 11 can be coated with silicon carbide or ferrite microwave absorbing coating 23, which can efficiently convert microwave energy into heat energy. The sample is indirectly heated through thermal radiation and convection, so that materials that cannot absorb microwaves can also achieve rapid heating. For example, Al2O3 particles can be heated from room temperature to 800°C within 5 minutes. 2. Compatible with complex reaction atmospheres: The modular design of the microwave-absorbing coating 23 and the insulation box 11 allows for flexible replacement of coating types according to different material properties (e.g., SiC is suitable for oxidizing atmospheres, while MoSi2 is suitable for reducing atmospheres), avoiding operational conflicts caused by the material limitations of heating elements in traditional resistance furnaces. For example, in the reduction reaction of metal oxides under H2 atmosphere, the MoSi2-coated insulation box 11 can operate stably at 1000℃ without oxidation. 3. Protecting the accuracy of the weighing module 17: The heat insulation design of the insulation box 11 (which can be made of alumina-based ceramic fiber composite material) can block >90% of radial heat conduction, keeping the operating temperature of the weighing module 17 below 50℃ and ensuring weighing accuracy.

[0038] This embodiment fills the gap in the adaptability of traditional microwave thermogravimetric analyzers to low dielectric materials by using a combined heating mechanism of microwave and thermal conduction, and provides a universal solution for the accurate thermal analysis of broad spectrum materials.

[0039] like Figure 4 The furnace cover 2 includes a lower connecting cylinder 201 and a top cover 202. The lower end of the lower connecting cylinder 201 is sealed to the upper end of the furnace body 1, and the air inlet pipe 8 is installed on the lower connecting cylinder 201. A lower hinge seat 31 is provided on one side of the lower connecting cylinder 201, and an upper hinge seat 30 is provided on the top cover 202 corresponding to the lower hinge seat 31. The rotating connecting shaft 32 passes through the upper hinge seat 30 and the lower hinge seat 31 from the side and is limited by the limiting nut. The top cover 202 is hinged to the lower connecting cylinder 201. The hinged top cover 202 is designed to enable one-handed opening and closing operation, which improves the convenience of experimental operation.

[0040] like Figure 5The furnace cover 2 is also provided with a quick-locking mechanism 13. The quick-locking mechanism 13 includes several connecting seats 1301 arranged circumferentially on the outer wall of the lower connecting cylinder 201. Each connecting seat 1301 is hinged with a guide rod 1302. A handwheel 1303 is threadedly connected to the guide rod 1302. The lower end of the handwheel 1303 is rotatably connected to a pressing sleeve 1304 through a bearing. The pressing sleeve 1304 is provided with a locking tooth 203 on the side near the top cover 202. The furnace cover 2 is provided with a locking groove that mates with the locking tooth 203.

[0041] A handle is provided on one side of the top cover 202. To open the cover, hold the handwheel 1303 and rotate it counterclockwise to disengage the retaining teeth 203 from the slots. Then, pull the guide rod 1302 downwards to open the quick-lock mechanism 13. Finally, hold the handle of the top cover 202 and rotate it to move the top cover 202 away. To close the cover, hold the handle of the top cover 202 and rotate it to engage the top cover 202 onto the connecting cylinder. Pull the guide rod 1302 upwards, then hold the handwheel 1303 and rotate it clockwise to engage the retaining teeth 203 in the slots, locking the quick-lock mechanism 13. The quick-lock mechanism 13 achieves rapid cavity sealing through multi-point synchronous pressing (3-6 evenly distributed points).

[0042] Since some heating requirements necessitate heating the material to a high temperature, this not only results in a high temperature in the heating chamber but also in a high temperature in the top cover 202, making it inconvenient to open the top cover 202 by hand. Therefore, in this embodiment, the top cover 202 is designed as a double-layer structure, including an upper cover and a lower cover, with a water-cooled chamber between the upper cover and the lower cover. The upper cover is equipped with an inlet pipe and an outlet pipe, and also includes a chiller unit. The inlet pipe is connected to the outlet end of the chiller unit, and the outlet pipe is connected to the return end of the chiller unit. The temperature of the top cover 202 is reduced by circulating chilled water in the water-cooled cavity. The chiller unit is existing technology; for example, it can be a water-cooled chiller unit, including a compressor, condenser, cooling tower, expansion valve, evaporator, water tank, and water pump. Initially, the compressor draws in low-temperature, low-pressure refrigerant gas after evaporation and cooling, then compresses it into high-temperature, high-pressure gas, which is sent to the condenser. The high-pressure, high-temperature gas is cooled by the condenser, condensing into a room-temperature, high-pressure liquid. When this liquid flows into the thermal expansion valve, it is throttled into low-temperature, low-pressure wet vapor, which flows into the shell-and-tube evaporator, absorbing heat from the chilled water and lowering its temperature. The evaporated refrigerant is then drawn back into the compressor, repeating the next refrigeration cycle. The refrigeration principles of other chiller units are not detailed here. The Trane CGAM series chiller unit can be used.

[0043] like Figure 7 As shown, a cooling fan 15 is installed on the support frame 20, and a heat dissipation pipe 16 is connected to the cooling fan 15. The heat dissipation pipe 16 is connected to the resonant cavity. The cooling fan 15 and the heat dissipation pipe 16 work together to reduce the temperature of the resonant cavity.

[0044] Furthermore, a flow meter is connected to the intake pipe 8, which enables precise control of the reaction gas flow rate and improves the controllability of the reaction.

[0045] A socket is installed on the top cover 202, into which a thermocouple 9 is inserted to detect the temperature inside the heating chamber. The thermocouple 9 is sealed to the socket; the thermocouple 9 can monitor the temperature of the heating chamber in real time. A pressure gauge 10 is connected to the lower connecting cylinder 201 to measure the air pressure inside the sealed heating chamber; the pressure gauge 10 is linked to the vacuum system to achieve closed-loop pressure control, which is particularly suitable for catalytic reaction research requiring a precise air pressure environment. The thermocouple 9 plays a role in temperature monitoring. The thermocouple 9, magnetron 4, cooling fan 15, chiller unit, and flow meter are all connected to the main controller; the target temperature is set through the main controller, and the thermocouple 9 provides real-time feedback of the heating chamber temperature data. When the temperature exceeds the limit, the main controller adjusts the power of the magnetron 4.

[0046] In particular, to facilitate the overall movement of this microwave well furnace, casters 12 are installed at the four corners of the bottom of the support frame 20. In this embodiment, the casters 12 can be Foma wheels.

[0047] In use, first open the top cover 202 to place the material 14, then close the top cover 202 and lock the quick-lock mechanism 13. If a vacuum heating environment is required, close the inlet valve 25 and the exhaust valve, open the suction valve, connect the vacuum tube 7 to the vacuum pump, and use the pressure gauge 10 to evacuate the sealed heating chamber. If an inert atmosphere heating environment is required, first use the vacuum pump to evacuate the sealed heating chamber to a basic vacuum (recommended ≤10-1Pa), then perform the first replacement. Slowly open the inlet valve 25, control the gas flow rate through the flow meter (e.g., 200 sccm), and fill with inert gas to atmospheric pressure (pressure gauge 10 shows 101 kPa). Then fully open the exhaust valve to discharge the gas. Repeat the above vacuuming, filling, and venting operations at least 3 times, and finally fill with inert gas to the target pressure (atmospheric pressure or slightly positive pressure). If a special reactive gas is required for the heating reaction, first evacuate to a vacuum level of 10⁻¹ Pa using a vacuum pump (evacuation before gas filling results in higher displacement efficiency). Then, fill with high-purity nitrogen to a slightly positive pressure (50 kPa). Repeat the evacuation-nitrogen filling cycle at least three times. Finally, introduce the reactive gas, precisely controlling the flow rate using a flow meter. For processes requiring continuous introduction of reactive gas and removal of reaction products (such as CVD deposition and gas reduction), a dynamic gas flow system must be established. This means that when introducing the special reactive gas, the exhaust valve must remain open. After the heating reaction is complete, follow the opening procedure to release the quick-lock mechanism 13, open the top cover 202, and remove the material 14 using a special tool. A Pfeiffer-HiCube-80-Eco vacuum pump can be used.

[0048] The above description is merely a preferred embodiment of the present utility model and does not limit the scope of the present utility model. All equivalent changes made based on the content of the present utility model specification and its drawings are included within the scope of the present utility model.

Claims

1. A microwave thermogravimetric analyzer characterized by: Includes a support frame (20), in which a furnace body (1) is installed. The upper end of the furnace body (1) is connected to a furnace cover (2), and the lower end is connected to a bottom sealing plate (3). The internal space of the furnace body (1), the furnace cover (2), and the bottom sealing plate (3) constitutes a resonant cavity. A magnetron (4) for emitting microwaves into the resonant cavity is installed on the furnace body (1). A weighing module (17) is also provided on the bottom sealing plate (3). A support rod (18) is connected to the weighing module (17). A weighing tray (19) for holding materials (14) is provided at the upper end of the support rod (18).

2. The microwave thermogravimetric analyzer according to claim 1, characterized by: A quartz tube (5) is installed inside the furnace body (1). The quartz tube (5) is sealed to the bottom sealing plate (3) and the furnace cover (2). The internal space of the quartz tube (5), the bottom sealing plate (3), and the furnace cover (2) constitutes a sealed heating chamber. The bottom sealing plate (3) is provided with a mounting shell (29) at the bottom. A through hole is provided on the bottom sealing plate (3). The weighing module (17) is installed in the mounting shell (29). The support rod (18) is inserted into the quartz tube (5) through the through hole. The bottom sealing plate (3) is connected to an exhaust pipe (6) and a vacuum pipe (7). The exhaust pipe (6) is connected to an exhaust valve, and the vacuum pipe (7) is connected to an air extraction valve. The furnace cover (2) is provided with an air inlet pipe (8), and the air inlet pipe (8) is connected to an air inlet valve (25).

3. The microwave thermogravimetric analyzer of claim 2, wherein: The furnace body (1) is provided with a first flange connecting plate (21) at the upper end and a second flange connecting plate (24) at the lower end. The bottom sealing plate (3) is bolted to the furnace body (1) through the second flange connecting plate (24). The furnace cover (2) is provided with a third flange connecting plate (22) at the lower edge. The side section of the third flange connecting plate (22) is an inverted L-shaped structure. The horizontal connecting plate of the third flange connecting plate (22) is bolted to the first flange connecting plate (21). The inner side of the first flange connecting plate (21) is provided with an upper connecting ring groove, and a first sealing ring (26) is provided in the upper connecting ring groove. The outer wall of the quartz tube (5) and the lower end of the vertical connecting plate of the third flange connecting plate (22) abut against the first sealing ring (26). The inner side of the second flange connecting plate (24) is provided with a lower connecting ring groove, and a second sealing ring (28) is provided in the lower connecting ring groove. An annular flange (27) is provided on the bottom sealing plate (3). The outer wall of the quartz tube (5) and the upper end of the annular flange (27) abut against the second sealing ring (28).

4. The microwave thermogravimetric analyzer of claim 2, wherein: The mounting housing (29) includes a side plate (2901) and a bottom plate (2902). The upper edge of the side plate (2901) is welded and fixed to the bottom sealing plate (3), and a horizontal connecting plate is provided on the lower edge. A sealing gasket is provided on the bottom plate (2902), and a first through hole for the connecting bolt to pass through is provided on the sealing gasket. The bottom plate (2902) is bolted and fixed to the horizontal connecting plate.

5. The microwave thermogravimetric analyzer of claim 2, wherein: A heat insulation pad is provided on the bottom sealing plate (3), and a second through hole is provided on the heat insulation pad for the support rod (18) to pass through.

6. The microwave thermogravimetric analyzer of claim 2, wherein: A bracket is also provided on the bottom sealing plate (3), and an insulated box (11) is provided on the bracket. The insulated box (11) is a spliced ​​structure, including a bottom support (1101), a surrounding plate (1102), and a box cover (1103). A third through hole is provided on the bottom support (1101) for the support rod (18) to pass through. The weighing tray (19) is located inside the insulated box (11). Furthermore, a wave-absorbing coating (23) is provided on the inner wall of the surrounding plate (1102).

7. The microwave thermogravimetric analyzer of claim 1, wherein: The furnace cover (2) includes a lower connecting cylinder (201) and a top cover (202). The lower end of the lower connecting cylinder (201) is sealed to the upper end of the furnace body (1). The air inlet pipe (8) is set on the lower connecting cylinder (201). A lower hinge seat (31) is provided on one side of the lower connecting cylinder (201). An upper hinge seat (30) is provided on the top cover (202) corresponding to the lower hinge seat (31). The rotating connecting shaft (32) passes through the upper hinge seat (30) and the lower hinge seat (31) from the side and is limited by the limiting nut. The top cover (202) is hinged to the lower connecting cylinder (201).

8. The microwave thermogravimetric analyzer of claim 7, wherein: The furnace cover (2) is also provided with a quick-lock mechanism (13). The quick-lock mechanism (13) includes several connecting seats (1301) arranged circumferentially on the outer wall of the lower connecting cylinder (201). Each connecting seat (1301) is hinged with a guide rod (1302). A handwheel (1303) is threaded onto the guide rod (1302). The lower end of the handwheel (1303) is rotatably connected to a pressing sleeve (1304) through a bearing. A locking tooth (203) is provided on the side of the pressing sleeve (1304) near the top cover (202). A slot that mates with the locking tooth (203) is provided on the furnace cover (2).

9. The microwave thermogravimetric analyzer of claim 7, wherein: A handle is provided on one side of the top cover (202). The top cover (202) has a double-layer structure, including an upper cover and a lower cover. The upper cover and the lower cover are connected to a water-cooled cavity. The upper cover is provided with an inlet pipe and an outlet pipe, and also includes a chiller unit. The inlet pipe is connected to the outlet end of the chiller unit, and the outlet pipe is connected to the return end of the chiller unit.

10. The microwave thermogravimetric analyzer of claim 7, wherein: A thermocouple (9) for detecting the temperature inside the heating chamber is provided on the top cover (202).

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