Nitrogen charging and pressure stabilizing mechanism for slurry transfer stirring tank of lithium battery pole piece coating machine

Abstract

The utility model relates to a nitrogen charging pressure stabilizing mechanism for a slurry transfer stirring tank of a lithium battery pole piece coating machine, which comprises a connector and an air inlet pipe, the connector is mounted on a tank body of the transfer stirring tank, the connector is provided with an air inlet and an air outlet on the inner side of the tank body, and the air inlet pipe is mounted on the connector and communicated with the air inlet; the gas inlet pipe is provided with a gas inlet valve assembly and connected with a gas source, a gas exhaust valve is arranged at the gas exhaust port, nitrogen of the gas source is conveyed into the slurry-free area in the tank body through the gas inlet pipe and the gas inlet, and gas in the slurry-free area is exhausted from the gas exhaust port under pushing of the nitrogen, so that the slurry-free area in the tank body is filled with the nitrogen. Nitrogen is filled into the tank body of the transfer stirring tank, air is exhausted, an inert gas environment is provided for slurry stirring, the slurry can be prevented from absorbing moisture from the air, the stability of the slurry is prevented from being affected by the reaction of the slurry with oxygen, carbon dioxide and other gases, and the stability and quality of the slurry after long-time stirring can be guaranteed.

Description

Technical Field

[0001] This utility model relates to the technical field of electrode coating equipment, and in particular to a nitrogen-filling and pressure-stabilizing mechanism for a slurry transfer and mixing tank in a lithium battery electrode coating machine. Background Technology

[0002] Currently, before electrode coating production, lithium battery coating machines are equipped with a feeding trolley. This trolley is equipped with a transfer and mixing tank for slurry transfer. To ensure slurry uniformity and prevent bubble formation, uncoated slurry needs to be circulated back into the transfer and mixing tank and continuously stirred with the remaining slurry. The upper part of the transfer and mixing tank is a slurry-free zone. There are certain gaps between the tank body and the lid opening, as well as other openings, allowing the slurry-free zone to be connected to the outside air to a certain extent.

[0003] Common organic solvents used in lithium battery cathode coating slurry include N-methylpyrrolidone (NMP), dimethyl carbonate (DMC), and diethyl carbonate (DEC). These slurry solvents are all water-free. If there is air in the slurry-free area, the slurry will absorb some water during the stirring process. When the slurry is coated onto the aluminum current collector, water, as a reaction medium, will accelerate the reaction between the aluminum in the aluminum current collector and oxygen in the air to form aluminum oxide. The aluminum oxide formed on the surface of the aluminum current collector will prevent the insertion and extraction of lithium ions, thus affecting the performance of the battery.

[0004] Meanwhile, if air is not removed during the stirring process, carbon dioxide in the air easily forms carbonic acid upon contact with water in the slurry. Carbonic acid alters the slurry's pH value. Polyvinylidene fluoride (PVDF), commonly used in positive electrode slurries, and polyacrylic acid (PAA) and lithium polyacrylate (PAA-Li), commonly used in negative electrode slurries, are all highly sensitive to pH changes. These pH changes alter the dispersion state of the binder and conductive agent. Furthermore, commonly used stabilizers such as barium sulfate and calcium carbonate, insulating filler materials like diatomaceous earth, and binder materials like clay minerals are prone to swelling and loosening after absorbing moisture. Changes in pH and the hygroscopic nature of other components affect the slurry's stability, leading to gel formation and potential blockage of the feed tube, thus preventing the coating process from proceeding. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides a nitrogen-filling and pressure-stabilizing mechanism for a slurry transfer and mixing tank in a coating machine.

[0006] This utility model provides a nitrogen-filling and pressure-stabilizing mechanism for a slurry transfer and mixing tank in a coating machine, including a connector and an air inlet pipe. The connector is installed on the tank body of the transfer and mixing tank. The connector has an air inlet and an air outlet on the inner side of the tank body. The air inlet pipe is installed on the connector and communicates with the air inlet. The air inlet pipe is equipped with an air inlet valve assembly and is connected to a gas source. An air outlet valve is provided at the air outlet. Nitrogen gas from the gas source is delivered into the slurry-free zone inside the tank body through the air inlet pipe and the air inlet. The gas in the slurry-free zone is discharged from the air outlet under the push of the nitrogen gas, so that the slurry-free zone inside the tank body is filled with nitrogen gas.

[0007] In some embodiments, the air inlet is provided with an air guide pipe inside the tank body. The airflow guided by the air guide pipe enters the tank body in the Q direction, which is a direction inclined towards the bottom of the tank body. The Q direction has an angle of less than 90° with the axial direction of the tank body.

[0008] In some embodiments, the air guide pipe includes a connecting section and an air guide section, which are perpendicular to each other and form an L-shape. The connecting section is connected to the air inlet and is perpendicular to the axial direction of the tank. The air guide section is inclined towards the bottom of the tank and has an angle of 45° with the axial direction of the tank.

[0009] In some embodiments, the air inlet extends through the connector along the thickness direction.

[0010] In some embodiments, the connector is provided with a pressure detection port, and a digital differential pressure gauge is installed at the pressure detection port.

[0011] In some embodiments, the outer wall of the connector is provided with two mounting surfaces for mounting an exhaust valve and a digital differential pressure gauge, respectively.

[0012] In some embodiments, the connector is provided with an arrow indicating the installation direction.

[0013] In some embodiments, the tank body is provided with an installation port, and both the connector and the installation port are provided with flanges. The flanges at the installation port and the flanges on the connector are fixed by quick-release clamps.

[0014] In some embodiments, the gas source is a nitrogen storage cylinder, and the inlet valve assembly includes a main valve, a manual shut-off valve, and an electromagnetic proportional valve. A pressure regulator and a pressure display gauge are provided between the manual shut-off valve and the main valve.

[0015] In some embodiments, the gas source is a nitrogen gas station, which is connected to the inlet of the connector via an inlet pipe and to the outlet of the connector via an outlet pipe.

[0016] Compared with the prior art, the advantages of this utility model are as follows: by filling the tank of the intermediate mixing tank with nitrogen and venting the air, an inert gas environment is provided for the mixing of the slurry, which can prevent the slurry from absorbing moisture from the air and prevent the slurry from reacting with gases such as oxygen and carbon dioxide, thus affecting the stability of the slurry. This ensures the stability and quality of the slurry after a long period of mixing. The air inlet and exhaust outlet are integrated on the connector, which can be installed on the tank in a quick-release manner using quick-release clamps, making it convenient for disassembly and maintenance. The air pressure inside the tank can be stabilized through the air inlet valve assembly and the exhaust valve. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural schematic diagram of a nitrogen-filling and pressure-stabilizing mechanism for a slurry transfer and mixing tank in a coating machine, according to an embodiment of this application.

[0018] Figure 2 This is a three-dimensional structural diagram of the tank body of the transfer mixing tank according to an embodiment of this application.

[0019] Figure 3 This is a schematic plan view of the tank body of the transfer mixing tank according to an embodiment of this application.

[0020] Figure 4 yes Figure 3 Schematic diagram of the cross-sectional structure of AA'.

[0021] Figure 5 This is a three-dimensional structural diagram of the connector according to an embodiment of this application.

[0022] Figure 6 This is one of the schematic diagrams of the internal structure of the connector in an embodiment of this application.

[0023] Figure 7 This is the second schematic diagram of the internal structure of the connector in an embodiment of this application.

[0024] Figure 8 This is a three-dimensional structural diagram of the intake valve assembly according to an embodiment of this application.

[0025] Attached reference numerals: 101, feeding trolley; 102, discharge pipe; 103, screw pump; 104, feed pipe; 105, circulating pipe; 106, quick-release clamp; 107, Q direction;

[0026] 1. Transfer mixing tank; 11. Tank body; 12. Mounting port; 13. Sealing ring;

[0027] 2. Connector; 21. Air inlet; 22. Exhaust outlet; 23. Pressure test port; 24. Mounting surface; 25. Arrow marking; 26. Flange;

[0028] 3. Air intake pipe;

[0029] 4. Intake valve assembly; 41. Main valve; 42. Manual stop valve; 43. Solenoid proportional valve; 44. Pressure regulator; 45. Pressure display gauge;

[0030] 5. Air guide tube; 51. Connecting section; 52. Air guide section;

[0031] 6. Exhaust valve;

[0032] 7. Exhaust pipe;

[0033] 8. Nitrogen storage cylinder;

[0034] 9. Digital differential pressure gauge. Detailed Implementation

[0035] The specific embodiments of this utility model are described with reference to the accompanying drawings.

[0036] refer to Figure 1 The figure shows a three-dimensional structural diagram of the nitrogen-filled pressure stabilizing mechanism for the slurry transfer and mixing tank 1 of the coating machine. The lower part is the loading trolley 101, which fixes the transfer and mixing tank 1. The loading trolley 101 is equipped with a discharge pipe 102 for conveying slurry and a screw pump 103. Above the transfer and mixing tank 1 are a circulation pipe 105 and an inlet pipe 104 for conveying slurry into the tank body 11. The loading trolley 101 can drive the transfer and mixing tank 1 to move. The discharge pipe 102, the inlet pipe 104 and the circulation pipe 105 are all installed by quick-release clamps 106, which can be quickly installed and removed.

[0037] In the coating process, some slurries require a thin coating or take a long time to complete the coating due to other reasons. At this time, the transfer mixing tank 1 needs to stir the slurry for a long time, which increases the influence of indoor air on the slurry. By using the nitrogen filling and pressure stabilizing mechanism of the transfer mixing tank 1 for the coating machine to fill the transfer mixing tank 1 with nitrogen and exhaust the air, an inert environment can be created to avoid the slurry absorbing moisture and other components in the air affecting the stability of the slurry.

[0038] refer to Figures 1 to 8 A nitrogen-filling and pressure-stabilizing mechanism for a slurry transfer and mixing tank 1 in a coating machine includes a connector 2 and an air inlet pipe 3. The connector 2 is installed on the tank body 11 of the transfer and mixing tank 1. The connector 2 has an air inlet 21 and an air outlet 22 on the inner side of the tank body 11. The air inlet pipe 3 is installed on the connector 2 and communicates with the air inlet 21. The air inlet pipe 3 is equipped with an air inlet valve assembly 4 and is connected to a gas source. An air outlet valve 6 is provided at the air outlet 22. Nitrogen gas from the gas source is delivered into the slurry-free zone inside the tank body 11 through the air inlet pipe 3 and the air inlet 21. The gas in the slurry-free zone is discharged from the air outlet 22 under the push of the nitrogen gas, so that the slurry-free zone inside the tank body 11 is filled with nitrogen gas.

[0039] The nitrogen-filling and pressure-stabilizing mechanism for the slurry transfer and mixing tank 1 of the coating machine in this embodiment fills the tank body 11 with nitrogen and discharges air, providing an inert gas environment for slurry mixing. This prevents the slurry from absorbing moisture from the air and avoids the slurry from reacting with gases such as oxygen and carbon dioxide, which would affect the stability of the slurry. This ensures the stability and quality of the slurry after a long period of mixing. The air inlet 21 and the exhaust port 22 are integrated on the connector 2. The connector 2 can be installed on the tank body 11 in a quick-release and quick-installation manner using the quick-release clamp 106, which is convenient for disassembly, assembly, and maintenance. The air pressure inside the tank body 11 can be stabilized through the air inlet valve assembly 4 and the exhaust valve 6.

[0040] In order to quickly expel the air from the tank 11, in this embodiment, reference is made to... Figure 4 The air inlet 21 is provided with an air guide pipe 5 inside the tank body 11. The airflow guided by the air guide pipe 5 enters the interior of the tank body 11 in the Q direction 107. The Q direction 107 is a direction inclined towards the bottom of the tank body 11. The Q direction 107 has an angle of less than 90° with the axis of the tank body 11.

[0041] Understandably, with this setup, the nitrogen gas flow is guided by the gas pipe 5 to flow downwards in the direction Q 107 into the tank 11. Since nitrogen is slightly lighter than air, the nitrogen gas flows downwards into the bottom of the tank 11, which can push the air at the bottom upwards and then push all the air inside the tank 11 to the exhaust port 22, thereby quickly expelling the air from the tank 11.

[0042] To facilitate the introduction of nitrogen gas into the tank 11, in this embodiment, reference is made to... Figures 4 to 7 The air guide pipe 5 includes a connecting section 51 and an air guide section 52. The connecting section 51 and the air guide section 52 are perpendicular to each other and form an L-shape. The connecting section 51 is connected to the air inlet 21 and is perpendicular to the axis of the tank body 11. The air guide section 52 is inclined towards the bottom of the tank body 11 and has an angle of 45° with the axis of the tank body 11.

[0043] Understandably, with this configuration, the connecting section 51 and the air inlet 21 are directly connected. The connecting section 51 is arranged radially along the tank body 11, and the air guide section 52 is perpendicular to the connecting section 51, guiding nitrogen into the tank body 11. The air guide section 52 forms a 45° air intake angle. The nitrogen gas flow is input downward at an angle of 45° through the connecting section 51 and the air guide section 52, which is conducive to the faster discharge of air below the tank body 11. The air density is slightly greater than that of nitrogen, and the downward air supply can lift the gas below upward more quickly, making it easier to discharge the air from the exhaust port 22 above.

[0044] To reduce obstruction to the nitrogen gas flow inside the input tank 11, in this embodiment, reference is made to... Figure 6 and Figure 7The air inlet 21 penetrates the connector 2 along the thickness direction.

[0045] Understandably, with this configuration, the air inlet 21 is through-through, and the connection section 51 between the air inlet 21 and the air guide pipe 5 is straight, to avoid excessive obstruction of airflow. The connection section 51 and the air guide section 52 of the air guide pipe 5 are curved to reduce obstruction of airflow.

[0046] In order to detect the air pressure inside the tank 11, in this embodiment, reference is made to... Figures 4 to 8 The connector 2 is equipped with a pressure detection port 23, and a digital differential pressure gauge 9 is installed at the pressure detection port 23.

[0047] Understandably, with this setup, the pressure detection port 23 allows the digital differential pressure gauge 9 to monitor the gas pressure inside the tank 11 in real time. This digital differential pressure gauge 9 feeds back the differential pressure value to the electromagnetic proportional valve 43 of the air inlet valve assembly 4 in real time. Based on the real-time differential pressure value fed back from inside the mixing tank, the electric proportional valve precisely controls the required working gas pressure of the nitrogen gas input into the tank 11, thereby better stabilizing the differential pressure inside the tank 11.

[0048] To facilitate the installation of the exhaust valve 6 and the digital differential pressure gauge 9, in this embodiment, refer to Figures 6 to 8 The outer wall of connector 2 is provided with two mounting surfaces 24 for mounting an exhaust valve 6 and a digital differential pressure gauge 9, respectively.

[0049] Understandably, with this configuration, the outer wall of connector 2 is cylindrical, which can better fit the mounting port 12 of tank 11. The exhaust valve 6 and the digital differential pressure gauge 9 are both threaded onto connector 2. Two mounting planes 24 are machined on the cylindrical surface, which can better position the exhaust valve 6 and the digital differential pressure gauge 9.

[0050] To ensure accurate installation of connector 2 and to guarantee that nitrogen is delivered into tank 11 at a certain angle, thereby accelerating the expulsion of air from tank 11, in this embodiment, reference is made to... Figures 6 to 8 The connector 2 is provided with an arrow mark 25 indicating the installation direction.

[0051] Understandably, with this configuration, the arrow mark 25 on the outer end face of the connector 2 is set radially outward. When the connector 2 is installed on the tank 11, the arrow mark 25 should point downward, so that the air guide section 52 of the air guide pipe 5 on the inner side of the connector 2 is set at an angle of 45° downward, ensuring that nitrogen enters the tank 11 at an angle of 45° downward, thus accelerating the discharge of air from the tank 11.

[0052] To facilitate the installation of connector 2, in this embodiment, refer to Figure 3 and Figure 6The tank body 11 is provided with an installation port 12, and both the connector 2 and the installation port 12 are provided with flanges 26. The flanges 26 at the installation port 12 and the flanges 26 on the connector 2 are fixed by quick-release clamps 106.

[0053] Understandably, with this setup, the air guide pipe 5 of connector 2 passes through the mounting port 12 and extends into the tank 11. The air guide section 52 of the air guide pipe 5 is inclined downward at 45°. The exhaust port 22 and the pressure detection port 23 are both connected to the inside of the tank 11. Then, the flange 26 of connector 2 and the flange 26 of mounting port 12 are fitted with quick-release clamps 106. Connector 2 is fixed by quick-release clamps 106. When maintenance is required, connector 2 can be quickly disassembled and assembled by quick-release clamps 106, improving maintenance efficiency.

[0054] In order to provide a stable gas source for the nitrogen gas charged into the transfer mixing tank 1, in this embodiment, reference is made to... Figure 1 The gas source is a nitrogen storage cylinder 8. The air inlet valve assembly 4 includes a main valve 41, a manual stop valve 42 and an electromagnetic proportional valve 43. A pressure regulator 44 and a pressure display gauge 45 are provided between the manual stop valve 42 and the main valve 41.

[0055] Understandably, with this setup, the main valve 41 is located near the loading trolley 101. The main valve 41 is a rotary shut-off valve, offering some flow and pressure regulation, but with relatively low precision. A nitrogen pressure regulator 44 and a secondary pressure gauge 45 are installed after the main valve 41. The pressure regulator 44 can modulate the gas source pressure to the precise operating pressure required (0.1–0.3 MPa). A manual shut-off valve 42 is installed after the pressure regulator 44, used to switch the gas source on and off during normal operation. An electro-proportional valve is installed after the manual shut-off valve 42. This electro-proportional valve uses the digital differential pressure gauge 9 to provide real-time feedback on the pressure difference within the mixing tank, precisely controlling the required working nitrogen pressure and thus stably controlling the gas pressure within the mixing tank. After all the air in the tank 11 is exhausted to the outside, the exhaust port 22 is closed, and the main valve 41, manual shut-off valve 42, and electro-proportional valve 43 are all opened, maintaining the nitrogen inlet passage and creating a positive pressure difference of 0.1–0.2 MPa between the gas pressure inside the mixing tank and the outside.

[0056] It should be further explained that the reference Figure 2 A sealing ring 13 is provided at the opening of the tank body 11. The sealing ring 13 seals the gap between the tank body 11 and the lid opening and closing, thereby improving the airtightness of the tank body 11.

[0057] In addition to using nitrogen storage cylinder 8 as the gas source, depending on the production conditions, the gas source can also be a nitrogen gas station. The nitrogen gas station is connected to the inlet 21 of connector 2 through inlet pipe 3 and to the outlet 22 of connector 2 through outlet pipe 7.

[0058] Understandably, with this setup, when a gas station is used as the gas source, the gas station, inlet pipe 3, inlet port 21, guide pipe 5, tank, exhaust port 22, and exhaust pipe 7 form a circulating gas path. The air inside the tank can be recovered by the gas station's gas recovery system through the exhaust pipe 7. The nitrogen from the gas station is transported to the tank 11 through the inlet pipe 3 until all the air inside the tank 11 is discharged. The gas pressure inside the tank 11 is around 0.1 MPa, and the circulation of nitrogen is ensured through a slight positive pressure.

[0059] This application embodiment uses a nitrogen-filling and pressure-stabilizing mechanism for the slurry transfer and mixing tank 1 of a coating machine. By filling the tank body 11 of the transfer and mixing tank 1 with nitrogen and venting air, an inert gas environment is provided for slurry mixing. This prevents the slurry from absorbing moisture from the air and avoids the slurry from reacting with gases such as oxygen and carbon dioxide, which would affect the stability of the slurry. This ensures the stability and quality of the slurry after a long period of mixing. The air inlet 21, the exhaust port 22, and the pressure detection port 23 are integrated on the connector 2. The connector 2 can be installed on the tank body 11 in a quick-release and quick-installation manner using a quick-release clamp 106, which is convenient for disassembly, assembly, and maintenance. Depending on the production conditions, either a nitrogen storage cylinder 8 or a gas station can be selected as the gas source to provide a stable gas source for filling the mixing tank with nitrogen. The air pressure inside the tank body 11 can be stabilized through the air inlet valve assembly 4 and the exhaust valve 6.

[0060] The above does not limit the technical scope of this utility model in any way. Any modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this utility model shall still fall within the scope of the technical solution of this utility model.

Claims

1. A nitrogen-filling pressure stabilizing mechanism for a coating machine pulp transfer mixing tank, characterized by, The utility model provides a nitrogen filling device for slurry tank, which comprises a connecting head, a gas inlet pipe, the connecting head is installed on the tank body of the transfer stirring tank, the connecting head is provided with a gas inlet and a gas outlet on the inside of the tank body, the gas inlet pipe is installed on the connecting head and communicates with the gas inlet, the gas inlet pipe is provided with a gas inlet valve assembly and is connected with a gas source, the gas outlet is provided with a gas outlet valve, nitrogen gas of the gas source is delivered into the slurry-free area in the tank body through the gas inlet pipe and the gas inlet, and the gas in the slurry-free area is discharged from the gas outlet under the push of nitrogen gas, so that the slurry-free area in the tank body is filled with nitrogen gas.

2. The nitrogen-filling pressure stabilizing mechanism for a coating machine pulp transfer mixing tank according to claim 1, characterized in that, The gas inlet is provided with a gas guide pipe on the inside of the tank body, the airflow guided through the gas guide pipe enters the inside of the tank body in the direction Q, the direction Q is a direction inclined to the bottom of the tank body, and the angle between the direction Q and the axial direction of the tank body is less than 90 degrees.

3. The nitrogen-filling pressure stabilizing mechanism for a coating machine pulp transfer mixing tank according to claim 2, characterized in that, The gas guide pipe comprises a connecting section and a gas guide section, the connecting section and the gas guide section are perpendicular to each other and form an L-shaped type, the connecting section is connected with the gas inlet, the connecting section is perpendicular to the axial direction of the tank body, and the gas guide section is inclined to the bottom of the tank body, and the angle between the gas guide section and the axial direction of the tank body is 45 degrees.

4. The nitrogen-filling pressure stabilizing mechanism for a coating machine pulp transfer mixing tank according to claim 1, characterized in that, The gas inlet penetrates the connecting head in the thickness direction.

5. The nitrogen-filling pressure stabilizing mechanism for a coating machine pulp transfer mixing tank according to claim 1, characterized in that, The connecting head is provided with a pressure detection port, and a digital differential pressure gauge is installed at the pressure detection port.

6. The nitrogen-filling pressure stabilizing mechanism for a coating machine pulp transfer mixing tank according to claim 5, characterized in that, Two installation planes for respectively installing the gas outlet valve and the digital differential pressure gauge are arranged on the outer side wall of the connecting head.

7. The nitrogen-filling pressure stabilizing mechanism for a coating machine pulp transfer mixing tank according to claim 1, characterized in that, An arrow mark indicating the installation direction is arranged on the connecting head.

8. The nitrogen-filling pressure stabilizing mechanism for a coating machine pulp transfer mixing tank according to claim 1, characterized in that, The tank body is provided with a mounting port, flanges are arranged on the connecting head and the mounting port, and the flange at the mounting port and the flange on the connecting head are fixed through a quick-mounting clamp.

9. The nitrogen-filling pressure stabilizing mechanism for a coating machine pulp transfer mixing tank according to claim 1, characterized in that, The gas source is a nitrogen gas cylinder, the gas inlet valve assembly comprises a total valve, a hand sliding stop valve and an electromagnetic proportional valve, a pressure reducer and a pressure display meter are arranged between the hand sliding stop valve and the total valve.

10. The nitrogen-filling pressure stabilizing mechanism for a coating machine pulp transfer mixing tank according to claim 1, characterized in that, The gas source is a nitrogen gas station, the nitrogen gas station is connected with the gas inlet of the connecting head through the gas inlet pipe and is connected with the gas outlet of the connecting head through the gas outlet pipe.

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