A headspace Karl Fischer moisture tester based on lithium battery safety detection

Abstract

The application discloses a headspace Karl Fischer moisture determinator based on lithium battery safety detection, and relates to the technical field of moisture determination, which comprises a heating furnace and a determinator, a placing groove is formed in the upper portion of the heating furnace, a container is installed on the upper portion of the determinator, a lifting mechanism is installed on the upper portion of the heating furnace, a thimble is installed at the bottom of the lifting mechanism, a movable box is movably connected to the bottom of the lifting mechanism, a circular groove is formed in the bottom of the movable box, a movable rod is slidably arranged on the inner side of the movable box, a pressure receiving rod is installed at the bottom of the lifting mechanism, a baffle is installed on the side of the movable rod, a sealing assembly is arranged on the movable box, the first air bag is inflated to extrude and wrap the end portion of the sample bottle through the sealing assembly, the second air bag transmits the gas to the third air bag to inflate the third air bag, the sealing of the thimble and the inlet of the sample bottle is improved, and the multiple sealing design effectively avoids the emission of moisture during the determination work.

Description

Technical Field

[0001] This invention relates to the field of moisture determination technology, and in particular to a headspace Karl Fischer moisture analyzer for lithium battery safety testing. Background Technology

[0002] The headspace Karl Fischer moisture analyzer is a precision instrument designed based on the Karl Fischer chemical reaction principle. It is specifically used to determine trace amounts of moisture in solid, high-viscosity liquid, and complex matrix samples. Its core function is to heat the sample in a sealed sample bottle to a set temperature using a programmable temperature-controlled furnace, causing the water bound or encapsulated inside the sample to evaporate into water vapor. The water vapor is then quantitatively transported to the Karl Fischer titration cell by a carrier gas such as high-purity nitrogen. The moisture content is accurately calculated through an electrolytic reaction. Moisture determination is essential for the safety testing of lithium batteries. The reaction between lithium salts in the lithium battery electrolyte and moisture produces highly corrosive hydrofluoric acid. Hydrofluoric acid corrodes the metal parts, casing, and seals inside the battery, leading to battery swelling, leakage, and even short circuits or explosions.

[0003] Conventional headspace Karl Fischer moisture analyzers typically rely solely on direct contact between the probe and the sample vial opening for sealing, lacking flexible sealing components such as air bladders. When measuring highly volatile samples such as lithium battery electrolytes, trace amounts of moisture may escape through the sealing gaps, leading to lower measured values ​​and affecting the accuracy of the measurement. Furthermore, after use, the probe is exposed to the external environment for extended periods, making it susceptible to adsorption and contamination by external impurities, thus affecting its usability. Therefore, a headspace Karl Fischer moisture analyzer for lithium battery safety testing is proposed. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies that rely on direct contact sealing between the probe and the sample bottle opening, which allows trace amounts of moisture to escape through the sealing gap, resulting in lower measured values ​​and affecting the accuracy of the measurement. Furthermore, after use, the probe is exposed to the external environment for a long time, making it susceptible to adsorption and contamination by external impurities, thus affecting the use of the probe. Therefore, this invention proposes a headspace Karl Fischer moisture analyzer for lithium battery safety testing.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A headspace Karl Fischer moisture analyzer for lithium battery safety testing includes a heating furnace and an analyzer. The heating furnace has a placement slot at its upper part, and a container is mounted on the upper part of the analyzer. A lifting mechanism is installed at the upper part of the heating furnace, and a pin is mounted at the bottom of the lifting mechanism. A movable box is movably connected to the bottom of the lifting mechanism, and a circular groove is formed at the bottom of the movable box. A movable rod is slidably disposed on the inner side of the movable box. A pressure rod is installed at the bottom of the lifting mechanism, and a baffle is installed on the side of the movable rod to prevent external impurities from entering the pin, affecting its service life and the accuracy of subsequent measurements, reducing the contact between the pin and the external environment, and minimizing pin contamination. To mitigate the risk, the movable box is equipped with a sealing assembly, which includes a first airbag installed at the bottom of the lifting mechanism, a second airbag installed on the outside of the ejector pin, multiple third airbags installed on the outside of the ejector pin, and an air supply unit installed inside the movable box. This multi-seal design increases the seal between the ejector pin and the sample bottle inlet, effectively preventing moisture loss during the measurement process and greatly improving the accuracy of moisture determination. A rotating ring is rotatably connected to the inside of the movable box, and a scraper is installed on the inside of the rotating ring. The rotating ring is connected to the movable rod to scrape the ejector pin surface, reducing the adsorption of impurities on the ejector pin surface and preventing impurities on the ejector pin surface from affecting the seal between the ejector pin and the sample bottle.

[0007] The above technical solution further includes:

[0008] The bottom of the lifting mechanism is equipped with a first telescopic rod, and the end of the first telescopic rod away from the lifting mechanism is fixedly connected to the movable box. The movable box is movably connected to the ejector pin.

[0009] A second telescopic rod is installed inside the movable box. The movable rod is installed at the end of the second telescopic rod. The cross-section of the pressure rod is trapezoidal. The pressure rod is located on the movement trajectory of the movable rod. When the lifting mechanism moves down, the pressure rod squeezes the movable rod.

[0010] The gas supply unit includes a cylinder installed inside the movable box, a piston slidably connected to the inside of the cylinder, a push rod installed on the side of the piston, and a fixed connection between the push rod and the movable rod on the side away from the piston. The movement of the movable rod can drive the piston to move inside the cylinder by the push rod.

[0011] The gas supply unit also includes a first delivery pipe and a second delivery pipe installed on the outside of the cylinder. The end of the first delivery pipe away from the cylinder is fixedly connected to the first airbag, and the end of the second delivery pipe away from the cylinder is fixedly connected to the second airbag. Gas is transmitted to the inside of the first airbag and the second airbag through the first delivery pipe and the second delivery pipe, respectively.

[0012] The surfaces of the multiple third airbags and the ejector pin are on the same horizontal line, and the second airbag is in communication with the multiple third airbags.

[0013] A rack is mounted on the side of the movable rod, a support plate is mounted on the inside of the movable box, the rotating ring is rotatably connected to the inside of the support plate, and a gear is mounted on the outside of the rotating ring. The gear meshes with the rack, and when the movable rod moves, it drives the rotating ring to rotate through the rack and gear.

[0014] The baffle has a trapezoidal cross-section, and the inner side of the movable box has a square groove.

[0015] The size of the circular groove opening is adapted to the diameter of the ejector pin.

[0016] The present invention has the following beneficial effects: 1. In this invention, after the measurement is completed, the baffle can automatically seal and protect the ejector pin, preventing external impurities from entering the ejector pin and affecting its service life and the accuracy of the next measurement. This reduces the contact between the ejector pin and the external environment and lowers the risk of the ejector pin being contaminated. 2. In this invention, by setting a sealing component, gas is respectively transmitted to the first airbag, the second airbag, and the third airbag. The first airbag expands to squeeze and wrap the end of the sample bottle, and the second airbag transmits the gas to the third airbag to make the third airbag expand. This increases the seal between the ejector pin and the inlet of the sample bottle. The multiple sealing design effectively avoids the loss of moisture during the measurement process, greatly improving the accuracy of the moisture measurement. In addition, the scraper on the rotating ring rotates accordingly and scrapes the surface of the ejector pin, reducing the adsorption of impurities on the ejector pin surface and preventing impurities on the ejector pin surface from affecting the seal between the ejector pin and the sample bottle. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of a headspace Karl Fischer moisture analyzer for lithium battery safety testing proposed in this invention.

[0018] Figure 2 This is a schematic cross-sectional view of the side of the movable box in this invention;

[0019] Figure 3 This is a schematic diagram of the bottom structure of the movable box in this invention;

[0020] Figure 4 for Figure 2 Enlarged schematic diagram of the structure at point A in the middle;

[0021] Figure 5 for Figure 2 Enlarged schematic diagram of the structure at point B;

[0022] Figure 6 for Figure 3Enlarged schematic diagram of the structure at point C.

[0023] In the diagram: 1. Heating furnace; 2. Placement trough; 3. Measuring instrument; 4. Container; 5. Lifting mechanism; 6. Pin; 7. First telescopic rod; 8. Movable box; 9. Second telescopic rod; 10. Movable rod; 11. Pressure rod; 12. Baffle; 13. Square groove; 14. Cylinder; 15. Piston; 16. Push rod; 17. First conveying pipe; 18. First airbag; 19. Second conveying pipe; 20. Second airbag; 21. Third airbag; 22. Support plate; 23. Rotating ring; 24. Scraper; 25. Rack; 26. Gear; 27. Circular groove. Detailed Implementation

[0024] 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.

[0025] Example 1

[0026] like Figure 1 - Figure 6 As shown, this invention proposes a headspace Karl Fischer moisture analyzer for lithium battery safety testing, comprising a heating furnace 1 and an analyzer 3. The heating furnace 1 has a placement slot 2 at its upper part, and a container 4 is mounted on the upper part of the analyzer 3. A lifting mechanism 5 is mounted on the upper part of the heating furnace 1, and a pin 6 is mounted on the bottom of the lifting mechanism 5. A movable box 8 is movably connected to the bottom of the lifting mechanism 5, and a circular groove 27 is formed on the bottom of the movable box 8. A movable rod 10 is slidably disposed on the inner side of the movable box 8. A pressure rod 11 is mounted on the bottom of the lifting mechanism 5, and a baffle 12 is mounted on the side of the movable rod 10 to prevent external impurities from entering the pin, affecting its service life and the accuracy of subsequent measurements, reducing the contact between the pin and the external environment, and lowering the risk of contamination. To mitigate the risk of needle contamination, the movable box 8 is equipped with a sealing assembly. This assembly includes a first airbag 18 mounted at the bottom of the lifting mechanism 5, a second airbag 20 mounted on the outside of the needle 6, multiple third airbags 21 mounted on the outside of the needle 6, and an air supply unit located inside the movable box 8. This multi-layered sealing design effectively prevents moisture loss during the measurement process, significantly improving the accuracy of moisture determination. A rotating ring 23 is rotatably connected to the inside of the movable box 8, and a scraper 24 is mounted on the inside of the rotating ring 23. The rotating ring 23 is connected to the movable rod 10 for transmission, scraping the needle surface to reduce the adsorption of impurities and prevent impurities from affecting the seal between the needle and the sample bottle.

[0027] The bottom of the lifting mechanism 5 is equipped with a first telescopic rod 7. The end of the first telescopic rod 7 away from the lifting mechanism 5 is fixedly connected to the movable box 8. The movable box 8 is movably connected to the ejector pin 6.

[0028] The inner side of the movable box 8 is equipped with a second telescopic rod 9, and the movable rod 10 is installed at the end of the second telescopic rod 9. The cross section of the pressure rod 11 is trapezoidal, and the pressure rod 11 is located on the movement trajectory of the movable rod 10. When the lifting mechanism 5 moves down, the pressure rod 11 squeezes the movable rod 10.

[0029] The baffle 12 has a trapezoidal cross section, and the inner side of the movable box 8 is provided with a square groove 13.

[0030] The size of the opening of the circular groove 27 is adapted to the diameter of the ejector pin 6.

[0031] In this embodiment, when moisture determination is required, the sample bottle containing the sample is placed in the placement slot 2. Then, the lifting mechanism 5 is pressed, which causes the ejector pin 6 and the movable box 8 to move downwards. First, the movable box 8 contacts the heating furnace 1, and at the same time, the first airbag 18 contacts the end of the sample bottle. At this time, the first telescopic rod 7 retracts. If the lifting mechanism 5 is pressed again, the movable box 8 remains stationary until the ejector pin 6 passes through the circular slot 27 and inserts into the sample bottle. While the movable box 8 remains stationary, the lifting mechanism 5 moves downwards, causing the pressure rod 11 to squeeze the movable rod 10, thereby moving the movable rod 10 away from the ejector pin 6. At this time, the second telescopic rod 9 retracts. The movable rod 10 moves the baffle 12 to one side of the circular groove 27, so that the baffle 12 no longer blocks the circular groove 27, making it easier for the ejector pin 6 to be inserted into the sample bottle. Then, the heating furnace 1 and the measuring instrument 3 are started to perform the measurement. After the measurement is completed, the lifting mechanism 5 moves the ejector pin 6 to the outside of the sample bottle. At the same time, the movable box 8 and the first airbag 18 are no longer in contact with the sample bottle. At this time, the first telescopic rod 7, which is in the contracted state, drives the movable box 8 to reset. At the same time, the movable rod 10 is no longer squeezed by the pressure rod 11. The second telescopic rod 9, which is in the contracted state, drives the movable rod 10 to reset, thereby driving the baffle 12 to reset and block the circular groove 27, which can seal and protect the ejector pin 6.

[0032] Example 2

[0033] like Figure 1 - Figure 6As shown, based on Embodiment 1, the air supply unit includes a cylinder 14 installed inside the movable box 8, a piston 15 slidably connected to the inside of the cylinder 14, a push rod 16 installed on the side of the piston 15, and the side of the push rod 16 away from the piston 15 is fixedly connected to the movable rod 10. The movement of the movable rod 10 can drive the piston 15 to move inside the cylinder 14 through the push rod 16.

[0034] The gas supply unit also includes a first delivery pipe 17 and a second delivery pipe 19 installed on the outside of the cylinder 14. The end of the first delivery pipe 17 away from the cylinder 14 is fixedly connected to the first airbag 18, and the end of the second delivery pipe 19 away from the cylinder 14 is fixedly connected to the second airbag 20. Gas is transmitted to the inside of the first airbag 18 and the second airbag 20 through the first delivery pipe 17 and the second delivery pipe 19 respectively.

[0035] The surfaces of the multiple third airbags 21 and the ejector pin 6 are on the same horizontal line, and the second airbag 20 is in communication with the multiple third airbags 21.

[0036] A rack 25 is mounted on the side of the movable rod 10, a support plate 22 is mounted on the inner side of the movable box 8, the rotating ring 23 is rotatably connected to the inner side of the support plate 22, and a gear 26 is mounted on the outer side of the rotating ring 23. The gear 26 meshes with the rack 25. When the movable rod 10 moves, it drives the rotating ring 23 to rotate through the rack 25 and the gear 26.

[0037] In this embodiment, when the movable rod 10 moves and drives the baffle 12 to one side of the circular groove 27, the movement of the movable rod 10 can drive the piston 15 to move inside the cylinder 14 via the push rod 16, thereby transmitting gas through the first delivery pipe 17 and the second delivery pipe 19 to the inside of the first airbag 18 and the second airbag 20 respectively. At this time, the first airbag 18 expands, thereby squeezing and wrapping the end of the sample bottle. At the same time, the second airbag 20 transmits gas to the third airbag 21. The third airbag 21 expands, increasing the seal between the ejector pin 6 and the sample bottle inlet, thereby protecting the ejector pin. 6. Multiple seals are applied to the sample vial to prevent moisture loss during the measurement process, which could affect the accuracy of the measurement. After the measurement is completed, when the ejector pin 6 moves upward through the rotating ring 23 and resets the movable rod 10, the movable rod 10 drives the rotating ring 23 to rotate via the rack 25 and gear 26. The rotation of the rotating ring 23 drives the scraper 24 to rotate and scrape the surface of the scraper 24. The scraped impurities fall into the square groove 13 through the guide of the baffle 12, reducing the adsorption of impurities on the surface of the ejector pin 6 and preventing impurities on the surface of the ejector pin 6 from affecting the seal between the ejector pin 6 and the sample vial.

[0038] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A headspace Karl Fischer moisture analyzer for lithium battery safety testing, comprising a heating furnace (1) and an analyzer (3), characterized in that, The upper part of the heating furnace (1) is provided with a placement groove (2), the upper part of the measuring instrument (3) is provided with a container (4), the upper part of the heating furnace (1) is provided with a lifting mechanism (5), the bottom of the lifting mechanism (5) is provided with a pin (6), the bottom of the lifting mechanism (5) is movably connected with a movable box (8), the bottom of the movable box (8) is provided with a circular groove (27), the inner side of the movable box (8) is slidably provided with a movable rod (10), the bottom of the lifting mechanism (5) is provided with a pressure rod (11), the movable rod (10) is slidably provided with a pressure rod (11), the bottom of the lifting mechanism (5) is provided with a pressure rod (11), the movable rod (10) is slidably provided with a pressure rod (11), the bottom of the lifting mechanism (5) is provided with a pressure rod (11), the bottom of the lifting mechanism (5) is slidably connected with a pressure rod (12), the bottom of the lifting mechanism (5) is slidably connected with a pressure rod (13), the bottom of the lifting mechanism (5) is slidably connected with a pressure rod (14), the bottom of the lifting mechanism (5) is slidably connected with a pressure rod (15), the bottom of the lifting mechanism (5) is slidably connected with a pressure rod (11), the bottom of the lifting mechanism (5) is slidably connected with a pressure rod (12), the bottom of the lifting mechanism (5) is slidably connected with a pressure rod (13 ... A baffle (12) is installed on the side of the movable box (8). A sealing assembly is provided on the movable box (8). The sealing assembly includes a first airbag (18) installed at the bottom of the lifting mechanism (5), a second airbag (20) installed on the outside of the ejector pin (6), a plurality of third airbags (21) installed on the outside of the ejector pin (6), and an air supply unit provided on the inside of the movable box (8). A rotating ring (23) is rotatably connected to the inside of the movable box (8). A scraper (24) is installed on the inside of the rotating ring (23). The rotating ring (23) is connected to the movable rod (10) by transmission.

2. The headspace Karl Fischer moisture analyzer for lithium battery safety testing according to claim 1, characterized in that, The bottom of the lifting mechanism (5) is equipped with a first telescopic rod (7), and the end of the first telescopic rod (7) away from the lifting mechanism (5) is fixedly connected to the movable box (8). The movable box (8) is movably connected to the ejector pin (6).

3. The headspace Karl Fischer moisture analyzer for lithium battery safety testing according to claim 1, characterized in that, The inner side of the movable box (8) is equipped with a second telescopic rod (9), the movable rod (10) is installed at the end of the second telescopic rod (9), the cross section of the pressure rod (11) is trapezoidal, and the pressure rod (11) is on the movement trajectory of the movable rod (10).

4. A headspace Karl Fischer moisture analyzer for lithium battery safety testing according to claim 1, characterized in that, The gas supply unit includes a cylinder (14) installed inside the movable box (8), a piston (15) slidably connected to the inside of the cylinder (14), a push rod (16) installed on the side of the piston (15), and the side of the push rod (16) away from the piston (15) is fixedly connected to the movable rod (10).

5. A headspace Karl Fischer moisture analyzer for lithium battery safety testing according to claim 4, characterized in that, The gas supply unit also includes a first delivery pipe (17) and a second delivery pipe (19) installed on the outside of the cylinder (14). The end of the first delivery pipe (17) away from the cylinder (14) is fixedly connected to the first airbag (18), and the end of the second delivery pipe (19) away from the cylinder (14) is fixedly connected to the second airbag (20).

6. A headspace Karl Fischer moisture analyzer for lithium battery safety testing according to claim 5, characterized in that, The surfaces of the multiple third airbags (21) and the ejector pin (6) are on the same horizontal line, and the second airbag (20) is in communication with the multiple third airbags (21).

7. A headspace Karl Fischer moisture analyzer for lithium battery safety testing according to claim 1, characterized in that, A rack (25) is installed on the side of the movable rod (10), a support plate (22) is installed on the inner side of the movable box (8), the rotating ring (23) is rotatably connected to the inner side of the support plate (22), and a gear (26) is installed on the outer side of the rotating ring (23), and the gear (26) meshes with the rack (25).

8. A headspace Karl Fischer moisture analyzer for lithium battery safety testing according to claim 1, characterized in that, The cross-section of the baffle (12) is trapezoidal, and the inner side of the movable box (8) is provided with a square groove (13).

9. A headspace Karl Fischer moisture analyzer for lithium battery safety testing according to claim 1, characterized in that, The size of the opening of the circular groove (27) is adapted to the diameter of the ejector pin (6).

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