A vacuum thermal gravimetric analyzer

Abstract

This invention relates to the field of thermogravimetric analysis technology and discloses a vacuum thermogravimetric analyzer, including an analyzer body. The analyzer body includes a vacuum-sealed balance cavity, which is formed by a top cover and a bottom cavity sealed together. A first gas pipe connector and a second gas pipe connector are located inside the bottom cavity, and a weighing assembly is suspended below the bottom cavity. This design eliminates interference from gas buoyancy, convection, and humidity through the vacuum-sealed cavity, avoiding measurement errors caused by the ambient atmosphere; a shock-absorbing ring isolates external mechanical vibrations, preventing unstable readings; a cooling tank circulates a cooling medium to block thermal radiation, avoiding interference from hot airflow and high-temperature aging of the sealing ring, preventing measurement drift and seal failure; and dual gas pipe connectors enable independent control of the protective gas and reaction gas, preventing sample volatiles from contaminating the balance and overcoming the limitation of not being able to control the atmosphere in separate zones. These improvements collectively enhance the accuracy, stability, and reliability of thermogravimetric analysis.

Description

Technical Field

[0001] This invention relates to the field of thermogravimetric analysis technology, specifically a vacuum thermogravimetric analyzer. Background Technology

[0002] Thermogravimetric analysis (TGA) is a technique that studies the thermal stability and composition of materials by measuring the change in sample mass over temperature or time. Performing TGA in a vacuum or controlled atmosphere effectively eliminates interference from factors such as gas buoyancy, convection, and humidity, which is crucial for improving the weighing accuracy of trace samples at high temperatures. In existing technologies, to reduce interference from the ambient atmosphere during the weighing process, the balance is typically placed within a sealed cavity, and the external atmosphere is isolated by evacuation or the introduction of a protective gas. For example, some analyzers use a heat insulation structure between the cavity and the heating furnace to reduce the impact of thermal radiation on the balance. Simultaneously, damping elements are installed at the connection between the weighing components and the cavity to isolate external mechanical vibrations. Furthermore, some devices employ a dual-channel gas control system, introducing different gases into the balance cavity and sample area respectively to prevent sample volatiles from contaminating the balance. These technical solutions improve the stability and accuracy of thermogravimetric analyzers to a certain extent. Through sealed cavities, damping elements, heat insulation structures, and independent atmosphere control, they can meet the analytical requirements under normal conditions. Nevertheless, existing devices still have certain limitations when dealing with complex operating conditions. For example, there is still room for further optimization in areas such as the effectiveness of thermal radiation blocking, the heat aging resistance of the sealing rings, and the long-term cleaning and maintenance of the weighing components, to better adapt to the requirements of high-precision and high-stability vacuum thermogravimetric analysis.

[0003] Therefore, since it does not meet the existing requirements, we propose a vacuum thermogravimetric analyzer. Summary of the Invention

[0004] This invention provides a vacuum thermogravimetric analyzer. This design eliminates interference from gas buoyancy, convection, and humidity through a vacuum-sealed cavity, avoiding measurement errors caused by ambient atmosphere. A shock-absorbing ring isolates external mechanical vibrations, preventing unstable readings. A cooling tank, circulated with a cooling medium, blocks thermal radiation, preventing interference from hot airflow and high-temperature aging of the sealing ring, thus preventing measurement drift and seal failure. A dual-gas connector allows for independent control of the protective gas and reaction gas, preventing sample volatiles from contaminating the balance and overcoming the limitation of inability to control the atmosphere in separate zones. These improvements collectively enhance the accuracy, stability, and reliability of thermogravimetric analysis, solving the problems mentioned in the background section.

[0005] The present invention provides the following technical solution: a vacuum thermogravimetric analyzer, comprising an analyzer body, the analyzer body comprising a vacuum-capable balance sealed cavity, the balance sealed cavity being formed by a top cover and a bottom cavity sealed together, the bottom cavity being provided with a first air pipe connector and a second air pipe connector, and a weighing component being suspended below the bottom cavity; The weighing assembly includes a sample carrying platform and a main rod. A heating furnace is also provided around the sealed cavity of the balance. The heating furnace is connected to the bottom cavity through a connector. The connector is a hollow structure and has a cooling groove integrally formed on the outside.

[0006] As an optional solution of the vacuum thermogravimetric analyzer described in this invention, a cleaning mechanism is provided in the internal cavity of the connector. The cleaning mechanism uses the vertical displacement of the weighing component as a driving source to realize the pulse purging cleaning function.

[0007] As an optional solution for the vacuum thermogravimetric analyzer described in this invention, the weighing assembly further includes three connecting rods. The upper ends of the three connecting rods are all fixedly installed on the sample carrying platform, and the lower ends are fixedly connected to the upper end of the main rod. The lower end of the main rod extends downward and passes through the bottom cavity into the internal cavity of the connector.

[0008] As an optional solution of the vacuum thermogravimetric analyzer described in this invention, the inner wall of the top of the internal cavity of the connector is provided with a freely rotatable rotating disk, the rotating disk and the main rod are connected by a thread, and four extrusion rods are evenly arranged along the circumferential direction on the bottom surface of the rotating disk.

[0009] As an optional solution of the vacuum thermogravimetric analyzer described in this invention, a striking cam is fixedly installed on the bottom surface of the rotating disk, the striking cam is coaxially arranged with the rotating disk, and a slidable striking hammer is provided on the inner wall of the internal cavity of the connecting member corresponding to the position of the striking cam.

[0010] As an optional solution for the vacuum thermogravimetric analyzer described in this invention, a gas storage bladder is provided at the bottom inner wall of the internal cavity of the connector, corresponding to the positions of the four extrusion rods. The gas storage bladder is an elastic sealed container and is equipped with a return spring inside. The gas storage bladder is equipped with an inlet one-way valve and an outlet one-way valve. The inlet one-way valve is connected to the gas passage where the first gas pipe connector is located through a pipeline. The outlet one-way valve is connected to the gas storage ring inside the bottom cavity through an output gas passage. A cleaning nozzle is provided on the gas storage ring.

[0011] As an optional solution of the vacuum thermogravimetric analyzer described in this invention, a striking cam is fixedly installed on the bottom surface of the rotating disk. The striking cam is coaxially and fixedly connected to the rotating disk. A protrusion is provided on the inner ring of the striking cam. A striking hammer is provided inside the protrusion. A return spring is provided between the striking hammer and the protrusion of the striking cam.

[0012] As an optional solution for the vacuum thermogravimetric analyzer described in this invention, a guide sleeve is fixedly installed on the inner wall of the cavity of the connector corresponding to the position of the striking hammer, and the striking hammer is slidably disposed in the guide sleeve.

[0013] As an optional solution for the vacuum thermogravimetric analyzer described in this invention, a guide sleeve is fixedly installed on the inner wall of the bottom of the connector, the guide sleeve is sleeved on the bottom of the main rod, and the outer wall of the guide sleeve is provided with extrusion protrusions corresponding to the striking hammer.

[0014] As an optional solution of the vacuum thermogravimetric analyzer described in this invention, a roller is rotatably mounted on the side or rear end of the striking hammer, and the roller maintains contact with the contour surface of the striking cam.

[0015] As an optional embodiment of the vacuum thermogravimetric analyzer described in this invention, the side of the impact hammer facing forward rotation is a gently sloping surface, while the side facing reverse rotation is a steeply rising impact surface.

[0016] The present invention has the following beneficial effects: This vacuum thermogravimetric analyzer employs a vacuum-sealed chamber to eliminate interference from gas buoyancy, convection, and humidity, avoiding measurement errors caused by ambient atmosphere. A shock-absorbing ring isolates external mechanical vibrations, preventing unstable readings. A cooling bath, circulated with a cooling medium, blocks thermal radiation, preventing interference from hot airflow and high-temperature aging of the sealing ring, thus preventing measurement drift and seal failure. A dual-gas connector allows for independent control of the protective and reaction gases, preventing sample volatiles from contaminating the balance and overcoming the limitation of inability to control the atmosphere in separate zones. These improvements collectively enhance the accuracy, stability, and reliability of thermogravimetric analysis.

[0017] This vacuum thermogravimetric analyzer utilizes a cleaning mechanism linked to the weighing components. This mechanism converts the up-and-down movement of the main rod into the rotational power of a rotating disk, driving a squeezing rod to periodically press the gas reservoir, achieving pulsed jet purging. An inclined nozzle is used to directionally remove volatile deposits from the surface of the weighing components, preventing mass drift. This design converts the equipment's own displacement into cleaning power, requiring no additional power source or manual intervention. The intermittent rebound of the gas reservoir generates pulsed airflow, effectively removing contaminants while avoiding interference from continuous airflow during the weighing process. Automatic purging is triggered during sample loading and unloading, ensuring timely cleaning before and after each experiment. This ingenious structure achieves independent cleaning and weighing, enhancing the equipment's automation level and long-term stability.

[0018] This vacuum thermogravimetric analyzer utilizes a striking cam, striking hammer, and return spring. The counter-rotating disc drives the striking hammer to strike the main rod, working in conjunction with pulse purging. This solves the problem of stubborn deposits being difficult to remove with simple airflow purging, preventing mass drift caused by volatile accumulation. The striking only occurs during sample unloading, avoiding interference with the weighing process during loading and ensuring measurement accuracy. The linked design requires no additional power source, resulting in a compact structure. The striking hammer's front end is covered with a flexible material, and the spring force is calibrated to prevent excessive striking force from damaging the sensor, extending the lifespan of the weighing components and improving long-term reliability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention; Figure 3 For the present invention Figure 2 A partial enlarged schematic diagram of the first structure in the middle; Figure 4 For the present invention Figure 2 A partial enlarged schematic diagram of the second structure.

[0020] Figure 5 For the present invention Figure 4 Enlarged structural diagram at point A in the middle; Figure 6 For the present invention Figure 4 Enlarged structural diagram at point B; Figure 7 This is a schematic diagram of the auxiliary cleaning component structure of the present invention.

[0021] In the diagram: 1. Analyzer body; 2. Weighing assembly; 101. Balance sealing cavity; 1011. Top cover; 1012. Bottom cavity; 102. First air pipe connector; 103. Second air pipe connector; 104. Heating furnace; 105. Connecting piece; 106. Cooling tank; 107. Rotating disc; 108. Extrusion rod; 109. Air storage bag; 110. Air storage ring; 111. Output air passage; 112. Cleaning nozzle; 113. Striking cam; 114. Guide sleeve; 115. Striking hammer; 116. Connecting spring; 201. Connecting rod; 202. Sample support platform; 203. Main rod. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1, please refer to Figures 1-7 The analyzer body 1 mainly includes a vacuum-sealed balance cavity 101, which is formed by a top cover 1011 and a bottom cavity 1012 sealed together. A sealing ring is provided between the two to ensure the airtightness of the cavity. The bottom cavity 1012 is also provided with a first gas pipe connector 102 and a second gas pipe connector 103, which are used to provide protective gas to the analyzer body 1 and to provide experimental gas to the sample heating zone, respectively.

[0024] A weighing assembly 2 is suspended below the bottom cavity 1012. The weighing assembly 2 includes three connecting rods 201, a main rod 203 (used as a contact sensor), and a sample carrying platform 202. The upper ends of the three connecting rods 201 are fixedly installed on the sample carrying platform 202, and the lower ends are fixedly connected to the main rod 203. In other words, the sample carrying platform 202 can be suspended inside the balance sealed cavity 101 using this setting. This suspension structure can effectively isolate external vibrations. Each connecting rod 201 is provided with a shock-absorbing ring at the connection between it and the top cover 1011 to further reduce the influence of external mechanical vibrations on the balance measurement.

[0025] Since a heating furnace 104 is also provided around the sealed cavity 101 of the balance, the heating furnace 104 is connected to the bottom cavity 1012 via a connector 105. The connector 105 is a hollow structure, and its upper and lower ends are respectively sealed to the bottom cavity 1012 and the heating furnace 104. Specifically, a first sealing ring is provided between the connector 105 and the bottom cavity 1012, and a second sealing ring is provided between the connector 105 and the heating furnace 104 to ensure the sealing of the vacuum cavity in the entire heating area. It should be noted that the first and second sealing rings are not shown in the figure, but the first and second sealing rings are usually made of materials with high temperature resistance, vacuum resistance and good chemical stability in the prior art, such as fluororubber or perfluoroether rubber. Users can adjust them according to actual conditions and their own needs, which will not be elaborated here. The outer side of the connector 105 is also integrally formed with a cooling groove 106, which can be filled with a cooling medium (such as circulating water) to block the heat generated by the heating furnace 104 from being transferred upward, avoid the hot airflow from interfering with the symmetrical distribution component 2, and at the same time protect the first sealing ring and the second sealing ring, extending their service life.

[0026] During analysis and testing, the balance sealing chamber 101 is first evacuated using an external vacuum pump to achieve the required vacuum level. If a specific gas is required, a reaction gas (such as oxygen or nitrogen) can be introduced into the sample heating zone through the second gas pipe connector 103, while a protective gas (such as an inert gas) is introduced into the area where the weighing component 2 is located through the first gas pipe connector 102 to prevent sample volatiles from contaminating the weighing component 2. The heating furnace 104 heats the sample according to a set program, and the change in sample mass on the sample carrying platform 202 is measured in real time by the weighing component 2 (i.e., the microbalance), and the data is output to the analysis system.

[0027] Since the entire weighing process is carried out in a vacuum environment, interference from gas buoyancy, convection, and humidity is eliminated. At the same time, the damping ring and cooling tank 106 ensure the stability of the weighing component 2 from the aspects of mechanical vibration and thermal radiation, respectively, thereby obtaining a high-precision thermogravimetric curve.

[0028] Compared with existing technologies, this solution has the following advantages: First, the vacuum environment eliminates the interaction between gas molecules and the sample, avoiding interference from airflow, humidity, buoyancy, etc., making the measurement results more accurate and stable. Second, the shock-absorbing ring effectively isolates external vibrations, improving the anti-interference capability of the weighing component 2. Third, the design of the cooling tank 106 not only blocks the heat radiation from the heating furnace 104 but also protects the sealing ring, extending the service life of the device. In addition, the dual gas pipe joints enable independent control of the protection of the weighing component 2 and the sample atmosphere, further improving the flexibility of the experiment and the reliability of the data. The entire device is compact and reliably sealed, providing a high-precision and high-stability weighing basis for vacuum thermogravimetric analysis.

[0029] Example 2 aims to address the issue of sample volatiles adhering to the surface of weighing component 2. This example is an improvement upon Example 1. For details, please refer to [link / reference]. Figures 1-7 In this solution, a cleaning mechanism is added to the internal cavity of the connector 105, and the pulse blowing cleaning function is realized by using the vertical displacement of the weighing component 2 as the driving source.

[0030] Since the weighing assembly 2 also includes a main rod 203, specifically, the upper ends of the three connecting rods 201 are all fixedly installed on the sample carrying platform 202, and the lower ends are fixedly connected to the upper end of the main rod 203, thereby suspending the main rod 203 inside the balance sealing cavity 101. Since the lower end of the main rod 203 extends downward, passes through the bottom cavity 1012 and extends into the internal cavity of the connector 105, and a freely rotatable rotating disk 107 is provided on the top inner wall of the internal cavity of the connector 105, the rotating disk 107 is threadedly connected to the main rod 203. When the main rod 203 moves up and down with the weighing assembly 2, the rotating disk 107 is driven to rotate through the threaded connection. Since four extrusion rods 108 are evenly arranged along the circumferential direction on the bottom surface of the rotating disk 107, each extrusion rod 108 rotates synchronously with the rotating disk 107.

[0031] At the bottom inner wall of the internal cavity of the connector 105, there is an air storage bag 109 corresponding to the four extrusion rods 108. The air storage bag 109 is an elastic sealed container with a return spring inside (not shown in the figure) and is equipped with an inlet one-way valve and an outlet one-way valve (not shown in the figure, and the inlet one-way valve and outlet one-way valve are commonly used and existing technologies in the art. Users can adjust them according to actual conditions and their own needs, and will not be described in detail here). The inlet one-way valve is connected to the external protective air source (i.e., the air passage where the first air pipe connector 102 is located) through a pipeline. The outlet one-way valve is connected to the air storage ring 110 inside the bottom cavity 1012 through the output air passage 111. The air storage ring 110 is circumferentially equipped with four cleaning nozzles 112.

[0032] When the extrusion rod 108 rotates with the rotating disk 107, it will extrude air into the air reservoir 109. After the extrusion rod 108 passes the air reservoir 109, the air reservoir 109 will rebound under the action of the return spring and re-inhale gas through the one-way valve.

[0033] Since the cleaning nozzle 112 installed on the gas storage ring 110 is inclined and the inclined direction is towards the key parts of the weighing component 2 (such as the root of the connecting rod 201 and the back of the sample carrying platform 202), it removes sample volatiles that may be deposited there.

[0034] During the constant temperature maintenance phase, the weighing component 2 remains stationary, the main rod 203 does not move, the rotating disk 107 does not rotate, the air storage bladder 109 does not move, and purging and stirring are suspended to ensure that the weighing process is not disturbed by airflow.

[0035] When the sample is unloaded, causing the weighing assembly 2 to move upward and reset, the main rod 203 moves upward synchronously and drives the rotating disk 107 to rotate in the opposite direction through the thread. At this time, the four extrusion rods 108 at the bottom of the rotating disk 107 extrude the gas storage bag 109 in the opposite direction again, generating pulse jets again, thereby performing pulse purging again, so that the purging during the upward movement process can further remove residual volatiles.

[0036] In other words, the above settings can automatically generate multiple high-speed airflow impacts in each experiment, effectively removing volatile deposits on the surface of weighing component 2, preventing mass drift caused by pollutant accumulation, maintaining weighing accuracy over a long period of time, and pulse purging saves more gas than continuous purging, while avoiding interference from continuous airflow in the weighing process.

[0037] Example 3 aims to solve the problem of stubborn adhesion of sample volatiles to the surface of weighing component 2, which is difficult to completely remove with simple airflow purging. This example is an improvement on Example 2. For details, please refer to Example 2. Figures 1-7 In this solution, the rotation of the rotating disk 107 is cleverly used as the driving source in the internal cavity of the connector 105 to achieve a linkage cleaning effect of pulse blowing and mechanical knocking. Specifically, a knocking cam 113 is fixedly installed on the bottom surface of the rotating disk 107. The knocking cam 113 is coaxially fixedly connected to the rotating disk 107. Its outline adopts an asymmetrical structure design, with a protrusion only set in the inner ring of the knocking cam 113. The knocking hammer 115 is set inside the protrusion. A connecting spring 116 is also set between the knocking hammer 115 and the protrusion of the knocking cam 113. The connecting spring 116 is always in a compressed state. It should be noted that the side of the protrusion of the knocking hammer 115 facing the forward rotation (i.e., the rotation direction of the rotating disk 107 when the sample is loaded) is a gently transitioning slope, while the side facing the reverse rotation (when the sample is unloaded) is a steeply rising impact surface.

[0038] Meanwhile, a guide sleeve 114 is fixedly installed on the inner wall of the bottom of the connector 105. The guide sleeve 114 is sleeved on the bottom of the main rod 203. The guide sleeve 114 not only guides the movement of the main rod 203, but also has a corresponding extrusion protrusion on the outer wall of the guide sleeve 114. To reduce friction, a roller can be rotatably mounted on the side or rear end of the striking hammer 115. The roller keeps in contact with the contour surface of the striking cam 113. To prevent excessive striking force from damaging the balance assembly 2 or affecting the accuracy of the balance, the front end of the striking hammer 115 is covered with a flexible material (such as polytetrafluoroethylene), and the elasticity of the connecting spring 116 is calibrated to ensure that the striking energy is only sufficient to shake off the attached object without causing permanent deformation of the sensor or zero drift.

[0039] In actual operation, when the rotating disk 107 rotates with the main rod 203, the striking cam 113 rotates synchronously. During the sample loading stage, the weighing component 2 moves downward, and the main rod 203 moves downward synchronously to drive the rotating disk 107 to rotate in the forward direction. Since the side of the striking hammer 115 facing the forward rotation is a gentle slope, the roller slides slowly along the slope, causing only a small displacement of the striking hammer 115, which is insufficient to trigger an effective impact. This avoids the striking action interfering with the weighing process and ensures the accuracy and stability of the measurement data.

[0040] During the sample unloading stage, the weighing component 2 moves upward to reset, and the main rod 203 moves upward synchronously to drive the rotating disk 107 to rotate in the opposite direction. At this time, the steep impact surface of the hammer 115 contacts the roller, pushing the hammer 115 to move forward quickly against the elastic force of the connecting spring 116 until the front end of the hammer 115 hits the main rod 203, generating a brief mechanical vibration. When the recessed part on the contour of the striking cam 113 rotates to the position of the roller, the hammer 115 retracts and resets under the push of the connecting spring 116, waiting for the next strike.

[0041] With the above design, during the sample unloading process, while the rotating disk 107 rotates in the opposite direction, the four squeezing rods 108 at its bottom squeeze the air storage bag 109 again to generate a second pulse purging. Meanwhile, the striking cam 113 synchronously drives the striking hammer 115 to generate mechanical knocking. The pulse purging and mechanical knocking work together. Since the sample has been unloaded, the brief vibration generated by the knocking will not affect the completed weighing results, but can effectively shake off any stubborn deposits that may remain, making up for the insufficiency of simple airflow purging in removing firm deposits.

[0042] This linkage design offers several advantages: First, mechanical tapping assists cleaning by using physical vibration to break the bond between stubborn deposits and the surface of the weighing component 2, resulting in more thorough and reliable cleaning, especially suitable for volatile substances in samples that are easily carbonized or highly viscous at high temperatures. Second, the tapping and purging actions are driven by the same rotating disk 107, achieving linkage between pulse purging and mechanical tapping. This eliminates the need for an additional power source and a complex control system, resulting in a compact structure and reliable transmission, fully demonstrating the ingenuity and efficiency of a purely mechanical design. Third, the tapping action only occurs during the sample unloading phase, when the weighing component 2 has already completed mass measurement and is in its return stroke. The vibration generated by the tapping will not interfere with the weighing process, ensuring accurate measurement. The accuracy and repeatability of the data are ensured. Furthermore, the asymmetrical contour design of the striking cam 113 cleverly achieves unidirectional selectivity—no striking during loading, striking during unloading—avoiding unnecessary mechanical impacts on the balance's lifespan. The guide sleeve 114 not only provides stable guidance for the main rod 203 but also serves as the impact target for the striking hammer 115, allowing the striking force to act directly on the main rod 203, effectively transmitting vibration to the entire suspension section of the weighing assembly 2 and maximizing the cleaning effect. The flexible material covering the front end of the striking hammer 115 and the elastic force calibration of the connecting spring 116 structurally ensure the controllability and safety of the striking force, guaranteeing both cleaning effectiveness and protection of the precision sensor. With long-term use, this mechanism can significantly reduce mass drift caused by volatile accumulation, extend the maintenance cycle of the weighing assembly 2, improve the overall reliability and data consistency of the vacuum thermogravimetric analyzer, and provide more comprehensive protection for high-precision thermogravimetric analysis.

[0043] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0044] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A vacuum thermogravimetric analyzer comprising an analyzer body (1), characterized in that: The analyzer body (1) includes a vacuum-sealed balance cavity (101), which is formed by a top cover (1011) and a bottom cavity (1012) sealed together. The bottom cavity (1012) is provided with a first air pipe connector (102) and a second air pipe connector (103). A weighing component (2) is suspended below the bottom cavity (1012). The weighing assembly (2) includes a sample carrying platform (202) and a main rod (203). A heating furnace (104) is also provided around the sealed cavity (101) of the balance. The heating furnace (104) is connected to the bottom cavity (1012) through a connector (105). The connector (105) is a hollow structure and has a cooling groove (106) integrally formed on the outside.

2. A vacuum thermogravimetric analyzer according to claim 1, characterized in that: The internal cavity of the connector (105) is provided with a cleaning mechanism. The cleaning mechanism uses the vertical displacement of the weighing component (2) as a driving source to realize the pulse blowing cleaning function.

3. A vacuum thermogravimetric analyzer according to claim 2, wherein: The weighing assembly (2) also includes three connecting rods (201). The upper ends of the three connecting rods (201) are fixedly installed on the sample carrying platform (202), and the lower ends are fixedly connected to the upper end of the main rod (203). The lower end of the main rod (203) extends downward and passes through the bottom cavity (1012) into the internal cavity of the connector (105).

4. A vacuum thermogravimetric analyzer according to claim 3, wherein: The inner wall of the top of the internal cavity of the connector (105) is provided with a freely rotatable rotating disk (107). The rotating disk (107) and the main rod (203) are connected by a thread. Four extrusion rods (108) are evenly arranged on the bottom surface of the rotating disk (107) along the circumferential direction.

5. A vacuum thermogravimetric analyzer according to claim 4, wherein: A striking cam (113) is fixedly installed on the bottom surface of the rotating disk (107). The striking cam (113) is coaxially arranged with the rotating disk (107). A sliding striking hammer (115) is provided on the inner wall of the cavity of the connector (105) corresponding to the position of the striking cam (113).

6. A vacuum thermogravimetric analyzer according to claim 5, wherein: An air reservoir (109) is provided at the bottom inner wall of the internal cavity of the connector (105) corresponding to the position of the four extrusion rods (108). The air reservoir (109) is an elastic sealed container and is equipped with a return spring inside. The air reservoir (109) is equipped with an inlet one-way valve and an outlet one-way valve. The inlet one-way valve is connected to the air passage where the first air pipe connector (102) is located through a pipeline. The outlet one-way valve is connected to the air storage ring (110) inside the bottom cavity (1012) through the outlet air passage (111). A cleaning nozzle (112) is provided on the air storage ring (110).

7. A vacuum thermogravimetric analyzer according to claim 4, wherein: A striking cam (113) is fixedly installed on the bottom surface of the rotating disk (107). The striking cam (113) is coaxially fixedly connected to the rotating disk (107). A protrusion is provided on the inner ring of the striking cam (113). A striking hammer (115) is provided inside the protrusion. A connecting spring (116) is provided between the striking hammer (115) and the protrusion of the striking cam (113).

8. A vacuum thermogravimetric analyzer according to claim 7, wherein: The connecting piece (105) is fixedly installed with a guide sleeve (114) on the inner wall of the bottom, the guide sleeve (114) is sleeved on the bottom of the main rod (203), and the outer wall of the guide sleeve (114) is provided with an extrusion protrusion corresponding to the knocking hammer (115).

9. A vacuum thermogravimetric analyzer according to claim 8, wherein: The side surface or rear end of the knocking hammer (115) is rotatably installed with a roller, and the roller is in contact with the profile surface of the knocking cam (113).

10. A vacuum thermogravimetric analyzer according to claim 9, wherein: The side surface or rear end of the knocking hammer (115) is rotatably installed with a roller, and the roller is in contact with the profile surface of the knocking cam (113).

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