Automatic cycle test system for getter pump

Abstract

The utility model relates to the technical field of getter testing, in particular to an automatic cycle testing system for a getter pump. The system comprises a vacuum chamber, a vacuumizing system, a baking temperature control system, an activation power supply, a cooling device and an air supply system, wherein valves, instruments, a heating power supply, a cooling power supply and an activation power supply on a connecting pipeline are connected with a data acquisition system and an automatic control system; besides, the vacuum chamber is divided into a Pm chamber and a Pg chamber by an orifice plate, the Pm chamber is connected with an air supply system, a to-be-detected getter pump is arranged in the Pg chamber, a valve switch in the system is controlled through a data acquisition system and an automatic control system, and circulation of heating activation, low-pressure air chamber pressure adjustment, cooling and air suction test is automatically completed. Meanwhile, the pressure of the Pm chamber and the pressure of the Pg chamber are recorded, and the inspiration rate, the inspiration capacity and corresponding curves are automatically calculated. According to the detection system and method, automatic control of multi-cycle inspiration testing can be realized, and the testing efficiency and the testing accuracy are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to getter testing technical field, concretely relates to a kind of getter pump automatic circulation test system. BACKGROUND

[0002] Getter pump is a kind of vacuum pump combined by getter array.Generally composed of non-evaporable getter alloy and heating assembly.Getter pump can absorb various active gases, such as hydrogen, oxygen, nitrogen, carbon monoxide, carbon dioxide, etc., after activation in vacuum system, but not absorb rare gas, applicable to improve the ultimate vacuum of other high vacuum pump (molecular pump, ion pump, oil diffusion pump, etc.) or maintain the working vacuum of small vacuum equipment, widely used in desktop and portable analysis system, synchrotron radiation source, particle accelerator, thin film deposition system, portable vacuum equipment and other fields.

[0003] Since the application field of getter pump mostly needs longer service life, the cycle service life of getter pump is a key parameter to determine whether getter pump can be practically applied.If getter pump performance declines due to irreversible reaction during cycle gas absorption and release, and cycle life ends, it will greatly affect the performance of getter pump in practical application.Under normal circumstances, for getter pump, cycle hydrogen absorption service life is required to be at least 100 times or more, so as to ensure long-time stable operation of high vacuum system.Therefore, the cycle service life of getter pump is a parameter that needs to be focused on, but a lot of manpower and time cost are needed in cycle test process, so a getter pump automatic circulation test system needs to be developed.

[0004] The test of the service life of the getter pump in circulation is to test the attenuation of the getter rate and the getter capacity with the number of circulation. In the prior art, a single test is usually carried out on the getter, for example, a getter test system is disclosed in Chinese Patent 202222674719.6, wherein a uniform hydrogen flow is directly introduced into a sample chamber, after the getter sample is activated, only a weak fixed gas flow is introduced, after a period of time, due to the saturation of the getter, the getter capacity is reduced, and the vacuum degree in the sample chamber is increased, at this time, a time value can be obtained, which can be used to measure the getter rate, and the getter amount can be calculated through the time and the uniform flow, so that the test and evaluation of the getter are realized. The test system focuses on the performance test of the getter material and product with small getter capacity, and the single getter capacity of the getter pump is large, especially for hydrogen. According to the measurement method of the getter rate of the test system, it takes more than a month for the getter to approach saturation, at this time, the pressure in the sample chamber is increased, and the attenuation of the getter rate is nonlinear, so the method for measuring the getter rate is inaccurate and inefficient, and the test and evaluation of the service life of the getter pump in circulation cannot be realized. Therefore, it is urgent to develop an automatic circulation test system for the getter pump, so as to obtain the change rule of the getter rate and the getter capacity with the number of circulation. Practical new type content

[0005] In order to overcome the shortcomings of the prior test technology, the utility model provides an automatic circulation test system for the getter pump:

[0006] An automatic circulation test system for the getter pump, comprising a vacuum chamber, a vacuum pumping system, a baking temperature control system, an activation power supply, a cooling device and a gas supply system, the gas supply system comprises a gas cylinder, a first pneumatic valve, a low-pressure gas chamber, a micro electric needle valve and a third pneumatic valve which are connected in series, and the low-pressure gas chamber is connected with an absolute pressure gauge; the vacuum pumping system comprises a series-connected electric butterfly valve and vacuum pump group, and the low-pressure gas chamber is connected with the vacuum pump group through a fourth pneumatic valve; the baking temperature control system is surrounded outside the vacuum chamber, and the cooling device is arranged to face the vacuum chamber; the vacuum chamber is divided into a Pm chamber and a Pg chamber by a hole flow plate, the Pm chamber and the Pg chamber are respectively connected with a Pm vacuum gauge and a Pg vacuum gauge, wherein the Pm chamber is connected with the third pneumatic valve and the electric butterfly valve, and the Pg chamber is arranged with a getter pump to be tested, and the activation power supply is connected with the getter pump through a cable; the first pneumatic valve, the absolute pressure gauge, the micro electric needle valve, the third pneumatic valve, the fourth pneumatic valve, the Pm vacuum gauge, the Pg vacuum gauge, the baking temperature control system, the activation power supply, the cooling device, the vacuum pump group and the electric butterfly valve are electrically connected with a data acquisition system and an automatic control system.

[0007] Further, the gas supply system is provided with a pressure reducing valve and a mass flow meter connected in series between the gas cylinder and the first pneumatic valve, and a second pneumatic valve connected in series between the low-pressure gas chamber and the micro electric needle valve, and the pressure reducing valve, the mass flow meter and the second pneumatic valve are electrically connected with the data acquisition system and the automatic control system.

[0008] Further, the baking temperature control system comprises a heating body and a thermocouple, the heating body is a heating jacket, a heating coil or a heating belt, and the heating body is wound outside the vacuum chamber.

[0009] Further, the cooling device is a fan and is located at the same horizontal plane as the vacuum chamber.

[0010] The utility model discloses beneficial effects are:

[0011] (1) the utility model discloses a vacuum chamber is divided into two chambers through the orifice flow plate, and the automatic control system is used to adjust the valve and control the pressure of the Pg chamber where the getter pump is located, and the pressure change of the Pm chamber is monitored and recorded. The setting of the gas supply system can buffer the airflow, create a stable test environment and avoid the error of the getter test result caused by the large fluctuation of the ventilation volume.

[0012] (2) the getter pump automatic circulation test system can realize the automatic control of the getter pump multiple circulation getter test, and the automatic control valve opening and closing, the low-pressure gas chamber pre-adjustment pressure automatic regulation, the Pg chamber pressure and the automatic regulation of the air intake flow in the ventilation test stage, which can avoid the test result deviation caused by the manual operation system and data recording, save the manpower and time cost in long-time continuous circulation test, improve the test efficiency and test accuracy. In addition, it is suitable for the sample with large single getter volume, and can realize the accurate evaluation of the service life of the getter pump. BRIEF DESCRIPTION OF DRAWINGS

[0013] The embodiments of the utility model will be further described below with reference to the drawings, wherein:

[0014] Figure 1 The flow chart of the embodiment of the getter pump automatic circulation test system is shown.

[0015] 1-gas cylinder; 2-pressure reducing valve; 3-mass flow meter; 4-first pneumatic valve; 5-low-pressure gas chamber; 6-absolutely pressure gauge; 7-second pneumatic valve; 8-micro electric needle valve; 9-third pneumatic valve; 10-vacuum chamber; 11-Pm vacuum gauge; 12-Pg vacuum gauge; 13-baking temperature control system; 14-getter pump; 15-activation power supply; 16-cooling device; 17-vacuum pump set; 18-electric butterfly valve; 19-orifice flow plate; 20-Pm chamber; 21-Pg chamber; 22-computer; 23-fourth pneumatic valve. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the utility model more clearly, the following will be further detailed by specific embodiments in combination with the drawings. It should be understood that the specific embodiments described herein are only used to explain the utility model, and are not used to limit the utility model.

[0017] In one embodiment, a getter pump automatic circulation test system, comprising a vacuum chamber 10, a vacuum system, a baking temperature control system 13, an activation power supply 15, a cooling device and a gas supply system:

[0018] The gas supply system includes a gas cylinder 1, a pressure reducing valve 2, a mass flow meter 3, a first pneumatic valve 4, a low-pressure gas chamber 5, a second pneumatic valve 7, a micro electric needle valve 8 and a third pneumatic valve 9 connected in series, the low-pressure gas chamber 5 is connected with an absolute pressure gauge 6, the data of the absolute pressure gauge 6 is transmitted to a data acquisition system, after the system analyzes and judges the deviation from the pre-adjusted initial pressure, the feedback is given to the automatic control system to control the opening and closing state of the first pneumatic valve 4 and the fourth pneumatic valve 23, as well as the flow size and on-off of the mass flow meter 3;

[0019] The vacuum system includes a motor-operated butterfly valve 18 and a vacuum pump group 17 connected in series, the vacuum pump group 17 and the motor-operated butterfly valve 18 are connected with the automatic control system through a cable, for controlling the start and stop of the vacuum pump group and the on-off of the motor-operated butterfly valve.

[0020] The low-pressure gas chamber 5 is connected with the vacuum pump group 17 through the fourth pneumatic valve 23;

[0021] The baking temperature control system 13 is surrounded outside the vacuum chamber 10, including a heating body and a thermocouple, the heating body is a heating coil, the heating coil is wound outside the vacuum chamber 10, the heating body and the thermocouple are connected with the data acquisition system and the automatic control system through a cable, for controlling the baking temperature and baking time of the system;

[0022] The cooling device 16 is arranged facing the vacuum chamber 10, specifically a fan, which is located at the same horizontal plane with the vacuum chamber 10 and blows directly to the vacuum chamber 10, connected with the data acquisition system and the automatic control system through a cable, for controlling the start and stop of the fan;

[0023] The vacuum chamber 10 is divided into Pm chamber 20 and Pg chamber 21 by the orifice plate 19, and the Pm chamber 20 and Pg chamber 21 are respectively connected with the Pm vacuum gauge 11 and Pg vacuum gauge 12, and the measurement data of the Pm vacuum gauge 11 and Pg vacuum gauge 12 are fed back to the data acquisition system and the automatic control system through cables. The Pm chamber 20 is connected with the third pneumatic valve 9 and the electric butterfly valve 18, and the Pg chamber 21 is internally provided with the getter pump 14 to be tested, and the activation power supply 15 is connected with the getter pump 14 through cables, and is also connected with the data acquisition system and the automatic control system through cables, and is used for regulating and controlling the activation current and the holding time of the getter pump;

[0024] In summary, the pressure reducing valve 2, the mass flow meter 3, the first pneumatic valve 4, the absolute pressure gauge 6, the second pneumatic valve 7, the micro electric needle valve 8, the third pneumatic valve 9, the fourth pneumatic valve 23, the Pm vacuum gauge 11, the Pg vacuum gauge 12, the baking temperature control system 13, the activation power supply 15, the cooling device 16, the vacuum pump set 17 and the electric butterfly valve 18 are connected with the data acquisition system and the automatic control system. The computer 22 is connected with the data acquisition system and the automatic control system, and is used for data input and display.

[0025] The getter pump automatic cycle test method using the above test system takes the 400L getter pump room temperature cycle hydrogen absorption performance test process as an example, and includes the following steps: (wherein the test gas can be H2, CO or N2, wherein the purity of H2 should be ≥99.99%, the purity of CO should be ≥99.95%, and the purity of N2 should be ≥99.95%.)

[0026] Step 1: Assemble the getter pump into the Pg chamber 21 of the vacuum chamber 10 through the CF interface;

[0027] Step 2: Start the vacuum pump set 17 and the electric butterfly valve 18 to exhaust the vacuum chamber 10, and the vacuum time is ≥20min, and the Pm vacuum gauge 11 and Pg vacuum gauge 12 are lower than 10 -3 Pa;

[0028] Step 3: Input the getter pump temperature 25℃, the vacuum chamber temperature 25℃, the low-pressure gas chamber volume 4000mL, the orifice plate small hole thickness 0.4mm and diameter 10mm, the baking temperature 230℃, the baking time 60min, the baking cutoff vacuum degree 2E-4Pa, the activation current 4.7A, the activation holding time ≥60min, the cooling time 100min, the test gas atmosphere H2, the gas conductance 33L / s, the test pressure Pg=1.8E-4Pa, the low-pressure gas chamber pre-adjustment initial pressure 1000Pa, the getter test time length 120min, and the cycle number 100 times in the automatic control system of the computer 22;

[0029] Step 4: After starting the baking temperature control system for 20 minutes, start the activation power supply 15, and activate it according to the set activation current and activation holding time until the set baking time and baking cutoff vacuum degree are met at the same time, and then turn off the baking temperature control system 13 and the activation power supply 15 at the same time;

[0030] Step 5: When the activation power supply 15 is started, that is, when the getter pump is activated, the pressure of the low-pressure gas chamber 5 is adjusted. When the initial pressure of the low-pressure gas chamber is lower than the set value, open all the valves on the path from the gas cylinder 1 to the first pneumatic valve 4 in sequence to perform the gas supplementing operation, and then close all the valves when the low-pressure gas chamber 5 reaches the set value. When the initial pressure of the low-pressure gas chamber is higher than the set value, open the fourth pneumatic valve 23 to pump out to 0.1 Pa or below, and then open all the valves on the path from the gas cylinder 1 to the first pneumatic valve 4 in sequence to perform the gas supplementing operation, and then close all the valves when the low-pressure gas chamber 5 reaches the set value.

[0031] Step 6: Start the cooling device 16 until the set cooling time is reached, and then turn it off.

[0032] Step 7: Open the second pneumatic valve 7 and the third pneumatic valve 9, and the micro electric needle valve 8 maintains the Pg vacuum gauge 12 at the set value of the test pressure Pg through automatic control of the flow rate, and records the pressure change of the Pm vacuum gauge 11, and then closes the second pneumatic valve 7, the micro electric needle valve 8, and the third pneumatic valve 9 after the single test duration is reached.

[0033] Step 8: Repeat steps 4 to 7, and each step 4 to 7 is one cycle, until the set number of cycles is completed.

[0034] The analysis data acquisition system collects the data signals in the system in real time, controls the valves through the automatic control system, and records the Pm vacuum gauge 11 and Pg vacuum gauge 12 data.

[0035] When the test gas is first used or replaced, open the fourth pneumatic valve 23 and the vacuum pump group 17 to pump out the low-pressure gas chamber 5 to 0.1 Pa or below to obtain the lowest possible background vacuum to ensure the purity of the test gas.

[0036] The computer 22 cooperates with the automatic control system and the data acquisition system, adjusts the pressure of the low-pressure gas chamber through the analysis of the data signals collected by the data acquisition system, controls the Pg vacuum gauge pressure in the getter test stage and adjusts the gas inlet flow rate, and calculates and analyzes the Pm vacuum gauge 11 and Pg vacuum gauge 12 data through the PLC and modules in the automatic control system, and outputs the gettering rate S and the gettering capacity Q in real time according to the following formula: t And the corresponding curve:

[0037]

[0038] wherein t is the test time; C is the orifice conductance; p m Pm is the vacuum gauge indication; p g Pg is the vacuum gauge indication.

[0039] wherein the activation current range of the activation power supply 15 is 0-20A; the measurement range of the absolute pressure gauge 6 is 0Pa-20000Pa; the measurement range of the mass flow meter 3 is 0-500sccm; the measurement range of the Pm vacuum gauge and the Pg vacuum gauge is 5.0*10 -7。 -1.0*10 0 Pa; the measurement range of the micro electrically driven needle valve is 1*10 -8 mbar-2.5bar; the flow control range of the mass flow controller is 3*10 -7 -75L / min.

[0040] The test method can automatically control the automatic circulation of the exhaust gas supplement of the gas supply system, the test pressure adjustment, the opening and closing of the valve, the baking activation, the cooling and the getter test after the completion of the getter pump through parameter setting without manual intervention, and can continuously test for a long time, thereby improving the test efficiency and avoiding the test result deviation caused by human factors.

[0041] The above describes some exemplary embodiments of the utility model, and it can be understood that the above embodiments are only used for explaining the utility model and do not constitute the limitation on the protection scope of the utility model. The features in these embodiments can be recombined in a suitable mode, and the scheme obtained thereby is still within the protection scope required by the utility model. Based on the above embodiments, all other embodiments obtained by the person skilled in the art without creative labor, namely all modifications, equivalent replacements and improvements made within the spirit and principles of the application, are within the protection scope required by the utility model.

Claims

1. A getter pump automatic cycle test system comprising a vacuum chamber (10), a vacuum pumping system, a baking temperature control system (13), an activation power supply (15), a cooling device and a gas supply system, characterized in that, The gas supply system comprises a gas cylinder (1), a first pneumatic valve (4), a low-pressure gas chamber (5), a micro electric needle valve (8) and a third pneumatic valve (9) connected in series, the low-pressure gas chamber (5) is connected with an absolute pressure gauge (6); the vacuum pumping system comprises a series connection of an electric butterfly valve (18) and a vacuum pump group (17), the low-pressure gas chamber (5) is connected with the vacuum pump group (17) via a fourth pneumatic valve (23); the baking temperature control system (13) is surrounded outside the vacuum chamber (10), the cooling device (16) is arranged to face the vacuum chamber (10); the vacuum chamber (10) is divided into a Pm chamber (20) and a Pg chamber (21) by a hole flow plate (19), the Pm chamber (20) and the Pg chamber (21) are respectively connected with a Pm vacuum gauge (11) and a Pg vacuum gauge (12), wherein the Pm chamber (20) is connected with the third pneumatic valve (9) and the electric butterfly valve (18), the Pg chamber (21) is built-in with a getter pump (14) to be measured, and an activation power supply (15) is connected with the getter pump (14) through a cable; the first pneumatic valve (4), the absolute pressure gauge (6), the micro electric needle valve (8), the third pneumatic valve (9), the fourth pneumatic valve (23), the Pm vacuum gauge (11), the Pg vacuum gauge (12), the baking temperature control system (13), the activation power supply (15), the cooling device (16), the vacuum pump group (17) and the electric butterfly valve (18) are electrically connected with a data acquisition system and an automatic control system.

2. A getter pump automatic cycle test system according to claim 1, characterized in that, The gas supply system further comprises a pressure reducing valve (2) and a mass flow meter (3) connected in series between the gas cylinder (1) and the first pneumatic valve (4), and a second pneumatic valve (7) connected in series between the low-pressure gas chamber (5) and the micro electric needle valve (8), wherein the pressure reducing valve (2), the mass flow meter (3) and the second pneumatic valve (7) are electrically connected with the data acquisition system and the automatic control system.

3. The automatic getter pump circulation test system according to claim 1, wherein The baking temperature control system (13) comprises a heating body and a thermocouple, the heating body is a heating sleeve, a heating coil or a heating belt, and the heating body is wound outside the vacuum chamber (10).

4. The automatic getter pump circulation test system according to claim 1, wherein The cooling device (16) is a fan, which is located at the same horizontal plane as the vacuum chamber (10).

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