Anode carbon block air permeability detection device and method

Abstract

This invention discloses an anode carbon block air permeability testing device and method, relating to the field of anode carbon block testing technology. The anode carbon block air permeability testing device includes a vacuum system, a gas supply system, and a sample testing body. The sample testing body includes a servo motor, a sleeve, sealing rubber tubing, and a fixed piston connected to a support platform. The testing method of the anode carbon block air permeability testing device includes sampling and sample pretreatment. Advantages: Compared with existing methods that can only place and test one sample at a time, this invention can place multiple samples simultaneously and test them sequentially. That is, after each sample is placed on its corresponding sample testing body, the gas supply system controls the sealing rubber tubing to simultaneously seal the sidewalls of each sample. Then, by switching the electromagnetic on / off valves, the vacuum system is used to test each sample sequentially. After one batch of samples is tested, another batch is replaced, greatly improving testing efficiency and reducing manual labor intensity.

Description

Technical fields:

[0001] This invention relates to the field of anode carbon block detection technology, and in particular to an anode carbon block air permeability detection device and method. Background technology:

[0002] Anode carbon blocks for aluminum electrolysis are made from petroleum coke as raw material and coal tar pitch as binder. The process involves petroleum coke calcination, crushing, screening, grinding, batching, mixing, molding, and roasting. The quality of anode carbon blocks is crucial for the normal production of electrolytic cells. To determine the quality of anode carbon blocks, it is usually necessary to test various performance indicators in advance, such as ash content, air permeability, and harmful impurities such as sodium, vanadium, and iron.

[0003] For electrolytic aluminum enterprises, the performance indicators of anode carbon blocks are a very important part, directly affecting the quality of aluminum. Therefore, it is a very important step to conduct incoming inspection of anode carbon blocks purchased by electrolytic aluminum enterprises. Among them, air permeability is an important indicator reflecting the quality of anode carbon blocks and has a significant impact on the excessive consumption of anodes during the electrolysis process.

[0004] Currently, when testing the air permeability of anode carbon blocks arriving in batches, multiple blocks are randomly selected proportionally, and multiple samples are taken from each block. Staff need to perform a lot of work, such as sample preparation, size measurement, and placing the samples on existing testing equipment for testing. In particular, during testing, each sample needs to be placed on the existing testing equipment for testing in sequence until all samples have been tested and compared with the pass standard (≤2npm). In addition to the initial sample preparation and size measurement, the current testing method consumes a lot of time in the process of taking and placing each sample on the existing testing equipment and testing them in sequence, resulting in low efficiency and high manual labor intensity in the entire testing process. Summary of the Invention:

[0005] The purpose of this invention is to provide an anode carbon block air permeability testing device and method that improves testing efficiency and reduces manual labor intensity.

[0006] This invention is implemented by the following technical solution: an anode carbon block air permeability detection device, comprising a vacuum system, a gas supply system, and one or more sample measuring bodies; the sample measuring body includes a servo motor, a sleeve, a sealing rubber tube, and a fixed piston connected to a support platform; the top of the fixed piston has a blind hole coaxially formed, and a vacuum channel is provided inside the fixed piston; the top of the vacuum channel communicates with the blind hole, and the bottom of the vacuum channel communicates with the vacuum system; a U-tube manometer is connected to the vacuum system; the sleeve is slidably fitted on the fixed piston, and a sliding pin is fixed to the outer wall of the sleeve; the servo motor is fixed on the support platform, and the output shaft of the servo motor is connected to a drive arm; a slot is formed on the drive arm that is fitted onto the sliding pin; a groove is formed circumferentially on the inner wall of the sleeve, and the sealing rubber tube is embedded in the groove; the air chamber of the sealing rubber tube communicates with the gas supply system.

[0007] Furthermore, the bottom of the blind hole is lined with porous filter paper, and the opening of the vacuum channel inside the blind hole is plugged with sponge rubber.

[0008] Furthermore, the sealing rubber tube includes an annular cavity and one or more sealing rings integrally formed with the inner side of the annular cavity, wherein the sealing rings communicate with the air chamber of the annular cavity.

[0009] Furthermore, elastic retaining rings are snapped onto the outer walls of the annular cavity on both sides of the sealing ring.

[0010] Furthermore, a horizontally arranged test platform is fixedly connected above the support platform. The test platform has through holes corresponding to each of the sample bodies, and the sleeve of the sample body moves through the corresponding through holes.

[0011] Furthermore, a support is connected to the test platform, and a pressing mechanism is correspondingly connected to the support directly above each of the test subjects; the pressing mechanism includes a push rod and a sleeve coaxially slidably sleeved on the push rod, the top end of the sleeve is fixedly connected to the support, the sleeve is coaxial with the corresponding fixed sleeve, and a spring is provided inside the sleeve to abut against the top end of the push rod.

[0012] Furthermore, the air supply system includes an air pump, an electromagnetic reversing valve, and an air supply pipeline. One end of the air supply pipeline is sealed and passes through the side wall of the sleeve and communicates with the air chamber of the annular cavity. The other end of the air supply pipeline is connected to one interface of the electromagnetic reversing valve. The air inlet and outlet of the air pump are correspondingly connected to two interfaces on the electromagnetic reversing valve.

[0013] Furthermore, the vacuum system includes a vacuum pump, a vacuum tank, vacuum branch pipes, and a vacuum main pipe. Each fixed piston has a vacuum channel bottom connected to a vacuum branch pipe. Each vacuum branch pipe is connected to one end of the vacuum main pipe, and the other end of the vacuum main pipe is connected to one end of the U-tube manometer. The vacuum main pipe is connected to the inlet of the vacuum tank via a bypass pipe, and the outlet of the vacuum tank is connected to the vacuum pump. An electromagnetic on / off valve is installed on each vacuum branch pipe, and an electromagnetic master valve is installed on the bypass pipe.

[0014] A method for detecting the air permeability of an anode carbon block, comprising sampling and sample pretreatment, and further comprising the following steps:

[0015] (1) Lift each top rod through the connecting frame, and place a standard sample and each sample to be tested on the fixed piston along the inner wall of the sleeve of the corresponding sample body;

[0016] (2) The air pump starts and draws air from the air supply line, causing the sealing rubber tubing to retract.

[0017] (3) When the servo motor is started, the sleeve is moved upward to the high position by the drive arm in cooperation with the slot and the sliding pin;

[0018] (4) Loosen the connecting bracket so that the bottom end of the push rod contacts the center of the sample. Under the action of the spring, the bottom end of the sample is tightly fitted with the fixed piston.

[0019] (5) Switch the solenoid reversing valve to the right working position. The air pump draws air from the atmosphere and sends it into the sealing rubber tube through the air supply line. The sealing ring expands to seal the side wall of the sample.

[0020] (6) Open the solenoid main valve and the solenoid on / off valve corresponding to the standard sample, and use the vacuum pump to evacuate. When the liquid level in the U-tube manometer reaches the position of sensor three, close the solenoid main valve and reduce the vacuum by passing the airflow through the sample. When the liquid level in the U-tube manometer reaches sensor two, record the time. When the liquid level reaches sensor one, record the time again. Then calculate the time difference tc between the two times.

[0021] (7) When the liquid level in the U-tube manometer returns to the position of the balance mark line in step (6), close the corresponding solenoid on / off valve to complete the detection of the standard sample;

[0022] (8) Repeat steps (6) and (7) to detect the time difference ts of each of the other samples in turn;

[0023] (9) After all samples have been tested, turn off the vacuum pump and the solenoid on / off valve; switch the solenoid reversing valve to the left working position, and the air pump draws air from the air supply line. After the sealing rubber tube retracts, turn off the air pump; lift each push rod upwards, and control the sleeve to move downwards to the low position by the servo motor, so that the upper part of each sample is exposed, making it easy to remove it, replace the next batch of samples to be tested, and repeat the above steps (1) to (8) for testing.

[0024] (10) Using the known air permeability Dc of the standard sample and the detection time difference tc, the correction factor fc is calculated using formula (I):

[0025]

[0026] In the formula, fc is the correction factor, and the unit is cubic meters per second.

[0027] tc — Time difference, in seconds;

[0028] Dc—Air permeability of the standard sample, in units of 10-1 -9 square meters;

[0029] 1963 — Cross-sectional area of ​​the sample when the diameter of the test sample is 50 mm, in square millimeters;

[0030] 20 — corresponds to the height of the test sample, in millimeters.

[0031] (11) Calculate the air permeability Ds of the test sample according to formula (II):

[0032]

[0033] In the formula, Ds is the air permeability of the test sample, in units of 10⁻⁶. -9 square meters;

[0034] ts — Time difference, in seconds;

[0035] hs — average height of the sample, in millimeters;

[0036] A—Cross-sectional area of ​​the sample, in square millimeters.

[0037] Furthermore, during sampling, a cylindrical sample was taken from a predetermined position on the anode carbon block using a hollow drill. The sample had a diameter of 50 mm and a length of 75 mm.

[0038] Sample pretreatment includes the following steps:

[0039] Step 1, Sample preparation: Cut off the end and take a 20 mm long sample, and blow away any adhering substances on it;

[0040] Step 2, Drying: Dry at 110℃±5℃ for 12 hours;

[0041] Step 3: Measure the height of the sample: Use calipers to measure the height of the cylindrical sample at 90° intervals along its circumference, with a deviation not exceeding 0.02mm. Calculate the average value hs of the height measurements.

[0042] Step 4: Measure the sample diameter: Use calipers to measure two sets of diameter data, with a 90° interval between the two sets. The deviation of each set should not exceed 0.02 mm. Measure the diameter data four times for each set, once at each of the upper and lower ends of the sample and twice at the midpoint of the axis. Calculate the average value ds of the two sets of diameter measurements, and then calculate the cross-sectional area A of the sample.

[0043] Advantages of this invention:

[0044] (1) Compared with the existing method that can only place and test one sample at a time, the present invention can place multiple samples at the same time and test them sequentially; that is, after each sample is placed on the corresponding test body, the gas supply system controls each sealing rubber tube to seal the side wall of each sample simultaneously, and then by switching each electromagnetic on and off valve, the vacuum system is used to test each sample sequentially. After one batch of samples is tested, another batch is replaced, which greatly improves the testing efficiency and reduces the intensity of manual labor.

[0045] (2) The pressing mechanism can simultaneously press down on each sample placed on the test platform, so that the bottom of the sample is tightly fitted with the corresponding fixed piston. No staff assistance is required, ensuring the efficiency and reliability of the test. Attached image description:

[0046] Figure 1 This is a schematic diagram of the structure of the present invention.

[0047] Figure 2 This is a schematic diagram of the gas supply system of the present invention.

[0048] Figure 3 This is a schematic diagram of the structure of the U-tube manometer described in this invention.

[0049] Figure 4 This is a partially enlarged schematic diagram of the sample measuring body described in this invention.

[0050] Figure 5 This is a partially enlarged schematic diagram of the sealing rubber tubing component described in this invention.

[0051] Figure 6 This is a schematic diagram of the usage state when the sleeve of the present invention is in its lowest position.

[0052] Figure 7 This is a schematic diagram of the usage state when the sleeve of the present invention is in its highest position.

[0053] Figure 8 This is a partially enlarged schematic diagram of the pressing mechanism described in this invention.

[0054] The components in the attached diagram are labeled as follows: Air pump 1, Solenoid directional valve 2, Air supply line 3, Vacuum pump 4, Vacuum tank 5, Main vacuum pipe 6, Vacuum branch pipe 7, U-tube manometer 8, Sensor 1 8.1, Sensor 2 8.2, Sensor 3 8.3, Bypass pipe 9, Solenoid on / off valve 10, Solenoid main valve 11, Sample measuring body 12, Servo motor 12.1, Sleeve 12.2, Groove 12.21, Snap ring 12.22, Sealing rubber tubing 12.3, Annular cavity 12.31 Body, 12.32 Sealing ring, 12.33 Elastic retaining ring, 12.4 Fixed piston, 12.41 Blind hole, 12.42 Vacuum channel, 12.5 Filter paper, 12.6 Sponge rubber, 12.7 Sliding pin, 12.8 Drive arm, 12.81 Groove, 13 Test platform, 13.1 Through hole, 14 Bracket, 15 Pressing mechanism, 15.1 Push rod, 15.2 Sleeve, 15.3 Spring, 15.4 Connecting frame, 16 Support platform. Detailed implementation method:

[0055] 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.

[0056] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "front", "rear", "top", "bottom", "left", "right", "vertical", "horizontal", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0057] Example 1: As Figures 1 to 3 As shown, this embodiment provides an anode carbon block air permeability testing device, which includes an air supply system, a vacuum system, and six sample measuring bodies 12.

[0058] The air supply system includes an air pump 1, a solenoid directional valve 2, and an air supply pipeline 3. One end of the air supply pipeline 3 is connected to one interface of the solenoid directional valve 2. The air inlet and outlet of the air pump 1 are connected to two interfaces on the solenoid directional valve 2 respectively. A two-position four-way solenoid directional valve 2 is used. When switched to the left working position, the air pump 1 draws air from the air supply pipeline 3 and releases it into the atmosphere. When switched to the right working position, the air pump 1 draws air from the atmosphere and sends it into the air supply pipeline 3. The left working position is the initial working state of the solenoid directional valve 2.

[0059] The vacuum system includes a vacuum pump 4, a vacuum tank 5, vacuum branch pipes 7, and a vacuum main pipe 6. Each vacuum branch pipe 7 is connected to one end of the vacuum main pipe 6, and the other end of the vacuum main pipe 6 is connected to one end of a U-tube manometer 8. The vacuum main pipe 6 is connected to the inlet of the vacuum tank 5 via a bypass pipe 9, and the outlet of the vacuum tank 5 is connected to the vacuum pump 4. An electromagnetic on / off valve 10 is installed on the vacuum branch pipe 7, and an electromagnetic master valve 11 is installed on the bypass pipe 9. Before the vacuum pump 4 is started, the electromagnetic on / off valve 10 and the electromagnetic master valve 11 are opened, and the vacuum tank 5 plays a role in stabilizing the pressure. The U-tube manometer 8 is equipped with three fork-shaped optical sensors. The lowest sensor, sensor 3 (8.3), is installed 145 mm below the balance mark line. The other two sensors are installed 30 mm (sensor 1, 8.1) and 80 mm (sensor 2, 8.2) below the balance mark line, respectively. Each sensor is electrically connected to the input terminal of the controller, and the output terminal of the controller is connected to a buzzer alarm to indicate the recorded time; or an existing controller that can automatically record time and calculate the time difference can be purchased.

[0060] like Figures 4 to 7 As shown, each sample testing body 12 includes a servo motor 12.1, a sleeve 12.2, a sealing rubber tube 12.3, and a fixed piston 12.4 connected to the support platform 16. The top of the fixed piston 12.4 has a blind hole 12.41 coaxially formed. The fixed piston 12.4 has a vacuum channel 12.42 inside. The top of the vacuum channel 12.42 is connected to the blind hole 12.41. The top of the fixed piston 12.4 is used to place the anode carbon block sample to be tested. The diameter of the fixed piston 12.4 is the same as the diameter of the anode carbon block. The bottom of the vacuum channel 12.42 is connected to a vacuum branch pipe 7. The bottom of the blind hole 12.41 is covered with porous filter paper 12.5. The opening of the vacuum channel 12.42 inside the blind hole 12.41 is plugged with sponge rubber 12.6, which allows air to pass through while blocking dust. The porous filter paper 12.5 and sponge rubber 12.6 protect the vacuum pump 4, preventing dust or sample particles from entering the vacuum pump 4 and causing damage.

[0061] Sleeve 12.2 is slidably fitted onto fixed piston 12.4. A sliding pin 12.7 is fixed to the outer wall of sleeve 12.2. A servo motor 12.1 is fixed on support platform 16. The output shaft of servo motor 12.1 is connected to drive arm 12.8. Drive arm 12.8 has a slot 12.81 that fits onto sliding pin 12.7. When sliding pin 12.7 is positioned at one end of slot 12.81, sleeve 12.2 is in its lowest position. The distance between the top of sleeve 12.2 and the top of fixed piston 12.4 is less than the sample height, facilitating sample placement. After sample placement, servo motor 12.1 drives drive arm 12.8 to swing, and slot 12.81 moves sliding pin 12.7, causing sleeve 12.2 to move upwards along fixed piston 12.4 to its highest position. The initial state of sleeve 12.2 is in its lowest position. Figure 6 As shown, a retaining ring 12.22 is integrally formed on the outer wall of the sleeve 12.2 along the circumferential direction and is movable and snapped onto the bottom surface of the test platform 13, which further limits the upward movement of the sleeve 12.2.

[0062] The inner wall of the sleeve 12.2 has a circumferentially circumferentially groove 12.21. A sealing rubber tube 12.3 is embedded in the groove 12.21. The sealing rubber tube 12.3 includes an annular cavity 12.31 and three sealing rings 12.32 integrally formed with the inner side of the annular cavity 12.31. The sealing rings 12.32 communicate with the air chamber of the annular cavity 12.31, and the outer walls of the annular cavity 12.31 on both sides of the sealing rings 12.32 are engaged. The elastic retaining ring 12.33 limits the position of the annular cavity 12.31; the other end of the gas supply pipe 3 is sealed and passes through the side wall of the sleeve 12.2, communicating with the air chamber of the annular cavity 12.31; before the sleeve 12.2 moves upward from the lower position, the gas supply system is controlled to draw air from the gas supply pipe 3, causing the sealing rubber fitting 12.3 to retract, preventing the sleeve 12.2 from touching and rubbing the sample during its upward movement; when the sleeve 12.2 moves upward to the highest position, if... Figure 7 As shown, the sealing rubber tube 12.3 corresponds to the position of the sample. The gas supply system is controlled to send gas to the gas supply line 3, causing the sealing rubber tube 12.3 to expand, ensuring that the sealing ring 12.32 is in contact with the side wall of the sample. The sealing rings 12.32 at both ends correspond to the upper and lower ends of the sample.

[0063] like Figure 8As shown, a horizontally arranged test platform 13 is fixedly connected above the support platform 16. The test platform 13 has through holes 13.1 corresponding to each sample body 12. The sleeve 12.2 of the sample body 12 moves through the corresponding through hole 13.1. A bracket 14 is connected to the test platform 13. A pressing mechanism 15 is correspondingly connected to the bracket 14 directly above each sample body 12. The pressing mechanism 15 includes a push rod 15.1 and a sleeve 15.2 coaxially slidably sleeved on the push rod 15.1. The top end of the sleeve 15.2 is fixedly connected to the bracket 14. The sleeve 15.2 is coaxial with the corresponding fixed sleeve 12.2. A spring 15.3 is provided inside the sleeve 15.2, abutting against the top end of the push rod 15.1. The bottom inner wall of sleeve 15.2 is integrally formed with a limiting edge along the circumference, and the top outer wall of push rod 15.1 is integrally formed with a protrusion that engages with the limiting edge of the corresponding sleeve 15.2, which serves as a limiting edge to prevent push rod 15.1 from coming off sleeve 15.2. The setting of the limiting edge and the protrusion is conventional technology in the field, and the specific structure is not shown separately in the attached drawings. The push rods 15.1 of each pressing mechanism 15 are connected by a connecting frame 15.4. Before placing the sample, push rod 15.1 is lifted, and spring 15.3 is compressed. After placing the sample, push rod 15.1 is released so that the bottom end of push rod 15.1 contacts the center of the sample. Under the action of spring 15.3, the bottom end of the sample is kept in close contact with the fixed piston 12.4.

[0064] Example 2: A method for detecting the air permeability of an anode carbon block, comprising the following steps:

[0065] Sampling was performed by taking cylindrical samples from the anode carbon block using a hollow drill. The samples were 50 mm in diameter and 75 mm in length.

[0066] Sample pretreatment includes the following steps: Step 1, Sample preparation: Cut off the ends and take a 20 mm long sample, and blow away any adhering substances; Step 2, Drying: Dry at 110℃±5℃ for 12 hours; Step 3, Measuring sample height: Use calipers to measure the height of the cylindrical sample at 90° intervals along its circumference, with a deviation not exceeding 0.02 mm, and calculate the average height measurement value hs; Step 4, Measuring sample diameter: Use calipers to measure two sets of diameter data, with a 90° interval between the two sets, and a deviation of not exceeding 0.02 mm for each set. Measure the diameter data four times for each set, once at each of the upper and lower ends of the sample and twice at the midpoint of the axis. Calculate the average diameter measurement value ds of the two sets, and then calculate the cross-sectional area A of the sample.

[0067] It also includes the following steps:

[0068] (1) Lift each top rod through the connecting frame, and place a standard sample and each sample to be tested on the fixed piston along the inner wall of the sleeve of the corresponding sample body;

[0069] (2) The air pump starts and draws air from the air supply line, causing the sealing rubber tubing to retract.

[0070] (3) When the servo motor is started, the sleeve is moved upward to the highest position by the drive arm in cooperation with the slot and the sliding pin;

[0071] (4) Loosen the connecting bracket so that the bottom end of the push rod contacts the center of the sample. Under the action of the spring, the bottom end of the sample is tightly fitted with the fixed piston.

[0072] (5) Switch the solenoid reversing valve to the right working position. The air pump draws air from the atmosphere and sends it into the sealing rubber tube through the air supply line. The sealing ring expands to seal the side wall of the sample.

[0073] (6) Open the solenoid main valve and the solenoid on / off valve corresponding to the standard sample, and use the vacuum pump to evacuate. When the liquid level in the U-tube manometer reaches the position of sensor three, close the solenoid main valve and reduce the vacuum by passing the airflow through the sample. When the liquid level in the U-tube manometer reaches sensor two, record the time. When the liquid level reaches sensor one, record the time again. Then calculate the time difference tc between the two times.

[0074] (7) When the liquid level in the U-tube manometer returns to the position of the balance mark line in step (6), close the corresponding solenoid on / off valve to complete the detection of the standard sample;

[0075] (8) Repeat steps (6) and (7) to detect the time difference ts of each of the other samples in turn;

[0076] (9) After all samples have been tested, turn off the vacuum pump and the solenoid on / off valve; switch the solenoid reversing valve to the left working position, and the air pump draws air from the air supply line. After the sealing rubber tube retracts, turn off the air pump; lift each push rod upwards, and control the sleeve to move downwards to the low position by the servo motor, so that the upper part of each sample is exposed, making it easy to remove it, replace the next batch of samples to be tested, and repeat the above steps (1) to (8) for testing.

[0077] (10) Using the known air permeability Dc of the standard sample and the detection time difference tc, the correction factor fc is calculated using formula (I):

[0078]

[0079] In the formula, fc is the correction factor, and the unit is cubic meters per second.

[0080] tc — Time difference, in seconds;

[0081] Dc—Air permeability of the standard sample, in units of 10-1 -9 square meters;

[0082] 1963 — Cross-sectional area of ​​the sample when the diameter of the test sample is 50 mm, in square millimeters;

[0083] 20 — corresponds to the height of the test sample, in millimeters.

[0084] (11) Calculate the air permeability Ds of the test sample according to formula (II):

[0085]

[0086] In the formula, Ds is the air permeability of the test sample, in units of 10⁻⁶. -9 square meters;

[0087] ts — Time difference, in seconds;

[0088] hs — average height of the sample, in millimeters;

[0089] A—The cross-sectional area of ​​the sample, in square millimeters.

[0090] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for detecting the air permeability of an anode carbon block, characterized in that, It includes a vacuum system, a gas supply system, and one or more sample measuring units; The sample measuring body includes a servo motor, a sleeve, a sealing rubber tube, and a fixed piston connected to a support platform. A blind hole is coaxially opened at the top of the fixed piston. A vacuum channel is provided inside the fixed piston. The top of the vacuum channel is connected to the blind hole, and the bottom of the vacuum channel is connected to a vacuum system. A U-tube manometer is connected to the vacuum system. The sleeve is slidably fitted onto the fixed piston, and a sliding pin is fixed to the outer wall of the sleeve; the servo motor is fixed on the support platform, and the output shaft of the servo motor is connected to a drive arm, and a slot is opened on the drive arm to fit onto the sliding pin; when the sliding pin is placed at one end of the slot, the sleeve is in its lowest position, and the distance between the top end of the sleeve and the top end of the fixed piston is less than the sample height, which facilitates sample placement. After the sample is placed, the servo motor drives the drive arm to swing, and the slot moves the sliding pin, causing the sleeve to move upward along the fixed piston to its highest position; The inner wall of the sleeve is provided with a groove along the circumference, and the sealing rubber tube is embedded in the groove. The air chamber of the sealing rubber tube is connected to the air supply system. A horizontally set test platform is fixedly connected above the support platform. The test platform has through holes corresponding to each of the test subjects. The sleeve of the test subject moves through the corresponding through hole. The test platform is connected to a bracket, and a pressing mechanism is connected to the bracket directly above each of the test samples. The pressing mechanism includes a push rod and a sleeve that is slidably sleeved on the push rod. The top end of the sleeve is fixedly connected to the bracket. The sleeve is coaxial with the corresponding sleeve. A spring is provided inside the sleeve to abut against the top end of the push rod.

2. The anode carbon block air permeability detection device according to claim 1, characterized in that, The bottom of the blind hole is lined with porous filter paper, and the opening of the vacuum channel inside the blind hole is plugged with sponge rubber.

3. The anode carbon block air permeability detection device according to claim 1, characterized in that, The sealing rubber tubing includes an annular cavity and one or more sealing rings integrally formed with the inner side of the annular cavity, wherein the sealing rings are in communication with the air chamber of the annular cavity.

4. The anode carbon block air permeability detection device according to claim 3, characterized in that, The outer walls of the annular cavity on both sides of the sealing ring are fitted with elastic retaining rings.

5. The anode carbon block air permeability detection device according to claim 3, characterized in that, The air supply system includes an air pump, an electromagnetic reversing valve, and an air supply pipeline. One end of the air supply pipeline is sealed and passes through the side wall of the sleeve and communicates with the air chamber of the annular cavity. The other end of the air supply pipeline is connected to one interface of the electromagnetic reversing valve. The air pump's inlet and outlet are connected to two interfaces on the electromagnetic reversing valve.

6. The anode carbon block air permeability detection device according to claim 1, characterized in that, The vacuum system includes a vacuum pump, a vacuum tank, vacuum branch pipes, and a vacuum main pipe. Each fixed piston has a vacuum channel bottom connected to a vacuum branch pipe. Each vacuum branch pipe is connected to one end of the vacuum main pipe, and the other end of the vacuum main pipe is connected to one end of the U-tube manometer. The vacuum main pipe is connected to the inlet of the vacuum tank via a bypass pipe, and the outlet of the vacuum tank is connected to the vacuum pump. An electromagnetic on / off valve is installed on each vacuum branch pipe, and an electromagnetic master valve is installed on the bypass pipe.

7. A detection method using the anode carbon block air permeability detection device according to any one of claims 1 to 6, comprising sampling and sample pretreatment, characterized in that, It also includes the following steps: (1) Lift each top rod through the connecting frame, and place a standard sample and each sample to be tested on the fixed piston along the inner wall of the sleeve of the corresponding sample body; (2) The air pump starts and draws air from the air supply line, causing the sealing rubber tubing to retract; (3) When the servo motor is started, the sleeve is moved upward to the high position by the drive arm in cooperation with the slot and the sliding pin; (4) Loosen the connecting frame so that the bottom end of the push rod contacts the center of the sample. Under the action of the spring, the bottom end of the sample is tightly fitted with the fixed piston. (5) Switch the electromagnetic reversing valve to the right working position. The air pump draws air from the atmosphere and sends it into the sealing rubber tube through the air supply line. The sealing ring expands to seal the side wall of the sample. (6) Open the main solenoid valve and the solenoid on / off valve corresponding to the standard sample, and use the vacuum pump to evacuate the vacuum. When the liquid level in the U-tube manometer reaches the position of sensor three, close the main solenoid valve and reduce the vacuum by passing the sample gas flow. When the liquid level in the U-tube manometer reaches sensor two, record the time. When the liquid level reaches sensor one, record the time again. Then calculate the time difference t between the two times. c ; (7) When the liquid level in the U-tube manometer returns to the position of the equilibrium mark line in step (6), close the corresponding solenoid on / off valve to complete the detection of the standard sample; (8) Repeat steps (6) and (7) to detect the time difference ts of each of the other samples in turn; (9) After all samples have been tested, turn off the vacuum pump and the solenoid on / off valve; switch the solenoid reversing valve to the left working position, and the air pump draws air from the air supply line. After the sealing rubber tube retracts, turn off the air pump; lift each push rod upwards, and control the sleeve to move downwards to the low position by the servo motor, so that the upper part of each sample is exposed, making it easy to remove it, replace the next batch of samples to be tested, and repeat the above steps (1) to (8) for testing. (10) Using the known air permeability D of the standard sample c The time difference t between detection and testing c The correction factor f is calculated using formula (1). c : ……………………(one) In the formula, f c —Correction factor, in cubic meters per second; t c —Time difference, in seconds; D c —Air permeability of the standard sample, in units of 10-1 -9 square meters; 1963 — Cross-sectional area of ​​the sample when the diameter of the test sample is 50 mm, in square millimeters; 20 — corresponds to the height of the test sample, in millimeters; (11) Calculate the air permeability D of the test sample according to formula (II). s : ……………………(two) In the formula, D s —The air permeability of the test sample, in units of 10-1 -9 square meters; t s —Time difference, in seconds; h s —The average height of the sample, in millimeters; A—The cross-sectional area of ​​the sample, in square millimeters.

8. The detection method of the anode carbon block air permeability detection device according to claim 7, characterized in that, During sampling, a cylindrical sample was taken from a predetermined position on the anode carbon block using a hollow drill. The sample had a diameter of 50 mm and a length of 75 mm. Sample pretreatment includes the following steps: Step 1, Sample preparation: Cut off the end and take a 20 mm long sample, and blow away any adhering substances on it; Step 2, Drying: Dry at 110℃±5℃ for 12 hours; Step 3: Measure the height of the sample: Use calipers to measure the height of the cylindrical sample at 90° intervals along its circumference. The deviation should not exceed 0.02mm. Calculate the average height measurement value h. s ; Step 4: Measure the sample diameter: Use calipers to measure two sets of diameter data, with a 90° interval between the two sets. The deviation of each set should not exceed 0.02mm. Measure the diameter four times for each set: once at the top and bottom ends of the sample, and twice at the midpoint of the axis. Calculate the average value d of the two sets of diameter measurements. s Then calculate the cross-sectional area A of the sample.

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