Vacuum degassing method and apparatus

Abstract

The application discloses a vacuum degassing method and device, comprising: vacuumizing the degassing chamber by a vacuum pump; making the liquid to be degassed flow into the degassing chamber and detecting the viscosity of the liquid to be degassed; setting the rotating speed of the magnetic stirrer and the frequency of the ultrasonic generator according to the viscosity, controlling the magnetic stirrer and the ultrasonic generator to carry out collaborative degassing, the magnetic stirrer is installed in the degassing chamber and cooperates with the magnetic stirrer outside the degassing chamber, the ultrasonic generator is installed outside the degassing chamber, when the magnetic stirrer rotates, the liquid to be degassed uniformly passes through the ultrasonic wave generated by the ultrasonic generator; when the preset air extraction condition is met, the magnetic stirrer and the ultrasonic generator are closed, after being rested for a preset time, the degassing chamber is vacuumized, and then the magnetic stirrer and the ultrasonic generator are controlled to carry out collaborative degassing until the preset completion condition is reached, and the liquid after degassing is obtained. Different viscosity liquids can be efficiently vacuum degassed.

Description

Technical Field

[0001] This invention relates to the field of liquid degassing technology, and in particular to a vacuum degassing method and apparatus. Background Technology

[0002] Common existing vacuum degassing methods include headspace method, bubbling method, and variable diameter piston method. Regardless of which vacuum degassing method is used, the principle is to make the degassing chamber a vacuum state and require good sealing. When the degassing liquid enters the degassing chamber under negative pressure from normal pressure, the change in pressure difference causes a change in the solubility of the gas in the liquid, and the gas components are released due to decompression.

[0003] Vacuum degassing is mostly suitable for degassing liquids with low viscosity. However, for relatively viscous liquids, the contact area between the gas and liquid phases is limited, making it difficult for dissolved gas at the bottom to precipitate out. This requires a longer time and results in lower degassing efficiency.

[0004] Therefore, current vacuum degassing methods are limited to low-viscosity liquids and their degassing efficiency needs to be improved. Summary of the Invention

[0005] The purpose of this invention is to provide a vacuum degassing method and apparatus that can efficiently degas liquids of different viscosities.

[0006] The technical solutions for achieving the above objectives include the following:

[0007] Vacuum degassing methods include:

[0008] A vacuum pump is used to evacuate the degassing chamber;

[0009] The liquid to be degassed is allowed to flow into the degassing chamber and its viscosity is measured.

[0010] The rotation speed of the magnetic stir bar and the frequency of the ultrasonic generator are set according to the viscosity. The magnetic stir bar and the ultrasonic generator are controlled to perform degassing in a coordinated manner. The magnetic stir bar is installed in the degassing chamber and cooperates with the magnetic stir bar outside the degassing chamber. The ultrasonic generator is installed outside the degassing chamber. When the magnetic stir bar rotates, the liquid to be degassed passes evenly through the ultrasonic waves generated by the ultrasonic generator.

[0011] When the preset evacuation conditions are met, the magnetic stirrer and the ultrasonic generator are turned off. After standing for a preset time, the degassing chamber is evacuated and the magnetic stirrer and the ultrasonic generator are controlled again to perform coordinated degassing until the preset completion conditions are met, and the degassed liquid is obtained.

[0012] In one embodiment, setting the rotation speed of the magnetic stir bar and the frequency of the ultrasonic generator according to the viscosity includes:

[0013] The viscosity range of the liquid is divided into a low viscosity range, a medium viscosity range, and a high viscosity range. A first speed range, a second speed range, and a third speed range are set for the low viscosity range, the medium viscosity range, and the high viscosity range, respectively, and the first speed range, the second speed range, and the third speed range are arranged from large to small.

[0014] When the viscosity is in the low viscosity range, the rotation speed is limited to the first rotation speed range; when the viscosity is in the medium viscosity range, the rotation speed is limited to the second rotation speed range; when the viscosity is in the high viscosity range, the rotation speed is limited to the third rotation speed range, and the frequency is limited to a preset frequency range.

[0015] In one embodiment, the first speed range is above 1000 rpm, the second speed range is 300 rpm to 1000 rpm, the third speed range is 100 rpm to 300 rpm, and the frequency range is 20 kHz to 30 kHz.

[0016] In one embodiment, the low viscosity range is less than 80 cP, the medium viscosity range is 80 cP to 500 cP, and the high viscosity range is greater than 500 cP.

[0017] In one embodiment, the vacuum pump is connected to a gas collection chamber, and the preset pumping condition is a preset time interval. Determining whether the preset completion condition has been met includes:

[0018] Obtain the current gas volume collected in the gas collection chamber, subtract it from the previous gas volume, and obtain the gas volume increment;

[0019] When the ratio of the gas volume increment to the total gas volume in the gas collection chamber is less than a preset threshold, it is determined that the preset completion condition has been met; otherwise, it is determined that the preset completion condition has not been met.

[0020] In one embodiment, a transducer is attached to the outer wall of the degassing chamber, and the transducer is connected to the ultrasonic generator.

[0021] In one embodiment, the vacuum pump is connected to a transfer solenoid valve, which is connected to a gas collection chamber or an exhaust pipe.

[0022] In one embodiment, when the liquid to be degassed flows into the degassing chamber, a vibratory viscometer is used to detect the viscosity of the liquid to be degassed.

[0023] The present invention also provides a vacuum degassing device, comprising:

[0024] The system includes a degassing chamber, a magnetic stirrer, an ultrasonic generator, a transducer, a magnetic stir bar, a vibratory viscometer, and a vacuum pump. One end of the vibratory viscometer extends into the degassing chamber to detect the viscosity of the liquid. The magnetic stirrer and the ultrasonic generator are installed outside the degassing chamber. The transducer is attached to the outer wall of the degassing chamber and connected to the ultrasonic generator. The vacuum pump is connected to the inner cavity of the degassing chamber. The magnetic stir bar is installed inside the degassing chamber and works in conjunction with the magnetic stirrer. A control device electrically connected to the magnetic stirrer, ultrasonic generator, and vibratory viscometer is also provided. This control device is used to set the rotational speed of the magnetic stir bar and the frequency of the ultrasonic generator according to the viscosity, controlling the magnetic stir bar and the ultrasonic generator to perform coordinated degassing.

[0025] In one embodiment, a transfer solenoid valve, a gas collecting chamber, and an exhaust pipe are also provided. The transfer solenoid valve is connected to the vacuum pump, the gas collecting chamber or the exhaust pipe is connected to the transfer solenoid valve, and / or a heating device is installed at the bottom of the degassing chamber.

[0026] The technical solution provided by this invention has the following advantages and effects:

[0027] This technology integrates vacuum degassing, ultrasonic degassing, and magnetic stirring. Magnetic stirring solves the problems associated with vacuum degassing and ultrasonic degassing when degassing high-viscosity liquids, overcoming the shortcomings of each individual technique. It can perform vacuum degassing on liquids of any viscosity. Furthermore, by detecting the liquid viscosity, the frequency of the ultrasonic generator and the rotation speed of the magnetic stirrer are adaptively set accordingly, improving degassing efficiency and shortening the detection cycle of the online monitoring device. Moreover, the use of non-contact magnetic stirring and ultrasonic degassing avoids liquid contamination and improves overall airtightness and vacuum degassing efficiency. Attached Figure Description

[0028] The accompanying drawings illustrate specific examples of the technical solutions described in this invention and, together with the detailed embodiments, form part of the specification, serving to explain the technical solutions, principles, and effects of this invention.

[0029] Unless otherwise specified or defined, the same reference numerals in different figures represent the same or similar technical features, and different reference numerals may be used to represent the same or similar technical features.

[0030] Figure 1 This is a schematic diagram of a vacuum degassing device;

[0031] Figure 2 This is a flowchart of a vacuum degassing method.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Liquid inlet, 2. Inlet solenoid valve, 3. Pressure sensor, 4. Pressure relief solenoid valve, 5. Vacuum solenoid valve, 6. Vacuum pump, 7. Transfer solenoid valve, 8. Degassing chamber, 9. Gas collection chamber, 10. Liquid level sensor, 11. Transducer, 12. Ultrasonic generator, 13. Outlet gear pump, 14. Magnetic stir bar, 15. Outlet solenoid valve, 16. Heater, 17. Magnetic stirrer, 18. Liquid outlet, 19. Vibratory viscometer. Detailed Implementation

[0034] To facilitate understanding of the present invention, specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings.

[0035] Unless otherwise specified or defined, the terms "first," "second," etc., used in this document are for distinguishing names only and do not represent a specific number or order.

[0036] Unless otherwise stated or defined, the term “and / or” as used herein includes any and all combinations of one or more of the related listed items.

[0037] It should be noted that when a component is considered "fixed" to another component, it can be directly fixed to the other component or there can be an intervening component; when a component is considered "connected" to another component, it can be directly connected to the other component or there can be an intervening component; when a component is considered "mounted" on another component, it can be directly mounted on the other component or there can be an intervening component; when a component is considered "placed" on another component, it can be directly placed on the other component or there can be an intervening component.

[0038] To address the issue that current vacuum degassing methods are limited to low-viscosity liquids and are not suitable for relatively viscous liquids, resulting in low degassing efficiency, this invention combines vacuum degassing with ultrasonic degassing, enabling vacuum degassing of liquids of any viscosity. Furthermore, to address the attenuation of ultrasonic waves in liquids, which affects the cavitation effect in deeper liquids, magnetic stirring technology is introduced. This not only increases the gas-liquid contact area but also ensures uniform ultrasonic cavitation of the liquid, increasing degassing efficiency. This invention combines multiple degassing principles, compensating for the shortcomings of individual technical approaches. Moreover, by setting appropriate stirring speeds and ultrasonic frequencies for liquids of different viscosities (such as viscous liquids, transformer oil, and water-based liquids), it enables highly efficient vacuum degassing of liquids of varying viscosities.

[0039] like Figure 1As shown, this embodiment provides a vacuum degassing device, mainly including: a degassing chamber 8, a magnetic stirrer 17, an ultrasonic generator 12, a transducer 11, a magnetic stir bar 14, a vibratory viscometer 19, and a vacuum pump 6. The degassing chamber 8 is a sealed tank structure. The magnetic stir bar 14 is installed inside the degassing chamber 8 and is located near the bottom. The magnetic stirrer 17 is installed below the degassing chamber 8. The magnetic stirrer 17 drives the magnetic stir bar 14 to rotate through magnetic force, thereby agitating the liquid to be degassed in the degassing chamber 8. When the inlet solenoid valve 2 is opened, the liquid to be degassed can enter the degassing chamber 8 from the liquid inlet 1.

[0040] A vibratory viscometer 19 is suspended on the top wall of the degassing chamber 8. When the degassing liquid enters the degassing chamber, the viscosity of the liquid to be degassed is detected by the vibratory viscometer 19.

[0041] The degassing chamber 8 is also equipped with a vacuum solenoid valve 5 and a vacuum pump 6, which are connected to the inner cavity of the degassing chamber 8. When the vacuum solenoid valve 5 is opened, the vacuum pump 6 can evacuate the degassing chamber 8. The outlet of the vacuum pump 6 is connected to a transfer solenoid valve 7, which is connected to the gas collecting chamber 9 and the exhaust pipe. The gas collecting chamber 9 is used to collect the gas extracted from the liquid to be degassed for subsequent testing. If it is not necessary to collect the extracted gas, the extracted gas can be directly discharged from the exhaust pipe through the transfer solenoid valve 7.

[0042] A transducer 11 is fitted onto the outer side wall of the degassing chamber 8, and the transducer 11 is connected to an ultrasonic generator 12. The ultrasonic generator 12 converts electrical energy into a high-frequency electrical signal, and the transducer 11 converts the high-frequency electrical signal into mechanical vibration, exciting a cavitation effect to achieve ultrasonic degassing. Specifically, ultrasonic degassing is a physical method that uses the cavitation effect generated by high-frequency sound waves to remove dissolved gases or entrained bubbles from a liquid. When ultrasound propagates in a liquid, it generates alternating high-pressure (compression) and low-pressure (rareness) cycles. In the low-pressure phase, a local negative pressure zone forms in the liquid, generating tiny vacuum bubbles. Gas dissolved in the liquid diffuses into the cavitation bubbles through the gas-liquid interface, and the bubbles gradually increase in size. The high-frequency vibration of the ultrasound promotes the collision and merging of the bubbles, accelerating their growth. Larger bubbles rise to the liquid surface due to buoyancy and burst, releasing gas into the environment.

[0043] However, ultrasonic degassing is mainly suitable for small-batch or continuous flow systems. In large-scale vacuum degassing (e.g., in static tank degassing), the attenuation of ultrasonic waves in the liquid affects the cavitation effect of the deeper liquid, potentially leading to uneven energy distribution and incomplete degassing. To address this problem with ultrasonic degassing, this embodiment uses a magnetic stirrer 17 and an ultrasonic generator 12 for synergistic degassing. During degassing, when the magnetic stirrer 17 drives the magnetic stir bar 14 to rotate, the liquid to be degassed can pass evenly through the transducer 11, ensuring that the liquid is uniformly exposed to the generated ultrasonic waves, thus solving the problem that ultrasonic waves cannot cavitate deeper liquids.

[0044] A liquid outlet 18 is provided on the bottom side wall of the degassing chamber 8, and an outlet solenoid valve 15 and an outlet gear pump 13 are installed on the liquid outlet 18. After degassing is completed, the degassed liquid in the degassing chamber 8 is discharged through the outlet solenoid valve 15 and the outlet gear pump 13.

[0045] It is important to emphasize that the airtightness of the degassing chamber 8 is particularly crucial for vacuum degassing. Therefore, this embodiment employs non-contact magnetic stirring and ultrasonic cavitation, whereby the magnetic stirrer 17, ultrasonic generator 12, and transducer 11 are all installed outside the degassing chamber 8. This method, unlike traditional mechanical stirring and bubbling stirring, eliminates the need for a transmission mechanism connecting the degassing chamber 8 to the outside environment, thus improving the overall airtightness of the degassing chamber 8 and eliminating concerns about the stirrer itself contaminating the liquid.

[0046] In some embodiments, a heating device may be installed at the bottom of the degassing chamber 8 to raise the temperature of the liquid to be stirred, thereby further improving the degassing rate. Specifically, in this embodiment, a heater 16 is installed at the bottom of the degassing chamber 8.

[0047] In this embodiment, a pressure sensor 3, a pressure relief solenoid valve 4, and a liquid level sensor 10 are also installed on the degassing chamber 8. The pressure sensor 3 is used to detect the gas pressure inside the degassing chamber 8, i.e., the vacuum level inside the degassing chamber 8; the pressure relief solenoid valve 4 is used to connect the degassing chamber 8 to the atmosphere; and the liquid level sensor 10 is used to detect the liquid level of the liquid to be degassed inside the degassing chamber 8.

[0048] It also includes a control device electrically connected to the magnetic stirrer 17, the ultrasonic generator 12 and the vibratory viscometer 19. This control device is used to set the rotation speed of the magnetic stir bar 14 and the frequency of the ultrasonic generator 12 according to the viscosity detected by the vibratory viscometer 19, and to control the magnetic stirrer 17 and the ultrasonic generator 12 to perform synergistic degassing.

[0049] The control device operates a vacuum degassing method, the specific steps of which are as follows: Figure 2 As shown, it includes:

[0050] Step S100: Use a vacuum pump to evacuate the degassing chamber;

[0051] Step S200: Allow the liquid to be degassed to flow into the degassing chamber and detect the viscosity of the liquid to be degassed;

[0052] Specifically, the vacuum solenoid valve 5 and vacuum pump 6 are opened, and the transfer solenoid valve 7 is connected to the exhaust pipe to evacuate the degassing chamber 8. The pressure in the degassing chamber 8 is monitored by the pressure sensor 3. Once the specified pressure or a vacuum degree of 90% or higher is reached, the vacuum solenoid valve 5 and vacuum pump 6 are closed to complete the vacuuming operation.

[0053] Then, open the inlet solenoid valve 2 to allow the liquid to be degassed to flow into the degassing chamber 8, while simultaneously monitoring the pressure sensor 3 and the liquid level sensor 10. Once the designated liquid level is reached, close the inlet solenoid valve 2. Read the value from the vibratory viscometer 19 to obtain the viscosity of the liquid to be degassed. The vibratory viscometer is an instrument that measures liquid viscosity by utilizing the damping effect of an object vibrating in a liquid, without relying on liquid flow; an example is the A&D SV series tuning fork vibratory viscometer.

[0054] Step S300: Set the rotation speed of the magnetic stirrer and the frequency of the ultrasonic generator according to the viscosity, and control the magnetic stirrer and the ultrasonic generator to perform degassing in a coordinated manner;

[0055] Specifically, magnetic stirring and ultrasonic degassing technologies are introduced on the basis of vacuum degassing to further increase the disorder within the degassing chamber and achieve a synergistic degassing effect. The magnetic stirrer agitates the surrounding liquid, and because the liquid to be degassed is subjected to continuous and uniform dynamic force, the effect is generally more uniform than manual or traditional mechanical stirring. Ultrasonic degassing utilizes the cavitation effect generated by high-frequency sound waves to remove dissolved gases from the liquid to be degassed. It is suitable for liquids of various viscosities and has high degassing efficiency. However, energy attenuation is severe in viscous liquids, and the cavitation effect is weakened. Therefore, magnetic stirring technology is used to compensate for this disadvantage by ensuring that the liquid to be degassed passes uniformly through the transducer.

[0056] The viscosity of the liquid to be degassed varies, requiring specific settings for the rotation speed of the magnetic stirrer and the frequency of the ultrasonic generator. In other words, the rotation speed of the magnetic stirrer and the frequency of the ultrasonic generator need to be adjusted according to the viscosity to improve the degassed efficiency of liquids of various viscosities. The rotation of the magnetic stirrer is controlled by a magnetic stirrer; setting the power of the magnetic stirrer correspondingly sets its rotation speed.

[0057] This embodiment divides the range of liquid viscosity into a low viscosity range (less than 80 cP), a medium viscosity range (80 cP to 500 cP), and a high viscosity range (greater than 500 cP). The first speed range (above 1000 rpm), the second speed range (300 rpm to 1000 rpm), and the third speed range (100 rpm to 300 rpm) are set for the low viscosity range, the medium viscosity range, and the high viscosity range, respectively. The first speed range, the second speed range, and the third speed range are arranged from largest to smallest.

[0058] When the viscosity of the liquid to be degassed is in the low viscosity range, the rotation speed of the magnetic stir bar 14 is limited to the first rotation speed range; when the viscosity is in the medium viscosity range, the rotation speed of the magnetic stir bar 14 is limited to the second rotation speed range; when the viscosity is in the high viscosity range, the rotation speed of the magnetic stir bar 14 is limited to the third rotation speed range.

[0059] Specifically, when the viscosity of the liquid to be degassed is detected to be high (>500 cP), the rotation speed of the magnetic stir bar 14 is automatically adjusted to a low speed. The required speed is only enough to overcome the static yield stress of the liquid and initiate flow. High-speed rotation requires extremely high torque, which can easily exceed the load capacity of the magnetic stirrer 17, causing the magnetic stir bar 14 to lose synchronization and making it difficult to achieve turbulence during stirring. Therefore, the rotation speed is limited to the range of 100-300 rpm, with lower speeds for higher viscosity liquids. Furthermore, for high-viscosity liquids, only low-frequency ultrasound is used; high-frequency ultrasound is not permitted. This is because low-frequency ultrasound has a longer wavelength, longer single-cycle time, and higher energy, providing more time for bubble growth in viscous media. The bubbles generated by low-frequency ultrasound are larger, and the energy released upon collapse is more powerful, sufficient to penetrate the molecular network of high-viscosity liquids and achieve effective degassing. Therefore, the frequency of the ultrasonic generator 12 is limited to the range of 20 kHz to 30 kHz, with lower frequencies for higher viscosity liquids.

[0060] When the viscosity of the liquid to be degassed is detected to be low (80 cP~500 cP), the stirring speed is automatically adjusted to high speed. Because of the low liquid resistance, the magnetic stir bar 14 can easily achieve high-speed rotation, and it is not easy to lose synchronization even at high speeds, and turbulence is easily achieved during the stirring process. Therefore, the speed is limited to the range of 300-1000 rpm.

[0061] When the viscosity of the liquid to be degassed is detected to be lower (<80 cP), the rotation speed can be further increased from 1000 rpm. At this time, the ultrasonic frequency can be flexibly adjusted. If the rotation speed is increased, the ultrasonic frequency can be appropriately increased (>80 kHz). High-frequency ultrasound has a shorter wavelength, more concentrated energy, and better directionality, but poor penetration. However, this disadvantage can be effectively mitigated by using magnetic stirring to ensure that the liquid to be degassed passes evenly through the transducer 11, thereby improving the degassed efficiency.

[0062] Step S400: When the preset evacuation conditions are met, turn off the magnetic stirrer and the ultrasonic generator, let it stand for a preset time, then evacuate the degassing chamber and re-control the magnetic stirrer and the ultrasonic generator to perform degassing in synergy until the preset completion conditions are met, and obtain the degassed liquid.

[0063] Henry's Law states that the solubility of a gas in a liquid is directly proportional to the partial pressure of that gas phase. As the pressure in the degassing chamber decreases, the dissolved gas in the liquid forms microbubbles, which escape through the gas-liquid interface, increasing the pressure in the degassing chamber. After a period of time, or when the pressure sensor 3 monitors that the pressure in the degassing chamber 8 reaches a preset pressure value, the magnetic stirrer 17 and the ultrasonic generator 12 are turned off. After a preset set time, the liquid phase in the degassing chamber 8 reaches a steady state. Then, the vacuum solenoid valve 5 and the vacuum pump 6 are opened to evacuate the degassing chamber 8. The magnetic stirrer 14 and the ultrasonic generator 12 are then controlled again for coordinated degassing. Vacuuming is repeated until the preset completion conditions are met, obtaining the degassed liquid. The preset completion conditions are set according to the degassing scenario and are not limited.

[0064] In this embodiment, the vacuum pump is connected to the gas collection chamber. Each time gas is pumped, it is collected in the gas collection chamber, which employs a piston design. The gas volume can be read from the scale or piston position. The preset pumping condition is a preset time interval, such as 5 minutes. The process of determining whether the preset completion condition has been met is as follows: First, obtain the gas volume collected in the gas collection chamber after the current vacuuming is completed, subtract it from the gas volume collected in the gas collection chamber after the previous vacuuming, and calculate the gas volume increment. Then, determine whether the preset completion condition has been met based on the gas volume increment, i.e., whether the ratio of the gas volume increment to the total gas volume is less than a set threshold. For example, when the ratio of the gas volume increment to the total gas volume is less than 5%, the preset completion condition is determined to have been met; otherwise, the preset completion condition is determined not to have been met.

[0065] In another embodiment, the preset air extraction condition is that the pressure in the degassing chamber reaches a preset value, and the preset completion condition is that the pressure in the degassing chamber does not reach the preset value even after a preset time has elapsed.

[0066] For example, the degassing process of the vacuum degassing device is as follows:

[0067] First, start the heater 16 to preheat the degassing chamber 8 to the specified temperature, open the pressure relief solenoid valve 4 to connect the degassing chamber 8 to the atmosphere, and at the same time calibrate the pressure sensor 3 by atmospheric pressure.

[0068] Open the vacuum solenoid valve 5 and vacuum pump 6, connect the transfer solenoid valve 7 to the exhaust pipe, monitor the pressure status of the degassing chamber 8 through the pressure sensor 3, and close the vacuum solenoid valve 5 and vacuum pump 6 after the specified pressure is reached.

[0069] Open the inlet solenoid valve 2 to allow the liquid to be degassed to flow into the degassing chamber, while monitoring the pressure sensor 3 and the liquid level sensor 10. After the specified liquid level is reached, close the inlet solenoid valve 2, read the value of the vibratory viscometer 19, and determine the frequency of the ultrasonic generator 12 and the rotation speed of the magnetic stir bar 14.

[0070] Turn on the magnetic stirrer 17 and the ultrasonic generator 12. Note that regardless of whether it is high-speed or low-speed mode, the speed should be gradually increased from low speed to the target speed. At the same time, maintain the temperature of the degassing chamber 8 at the required temperature and monitor the pressure through the pressure sensor 3.

[0071] After a period of time, turn off the magnetic stirrer 17 and the ultrasonic generator 12, and let it stand for a period of time to allow the liquid in the degassing chamber 8 to reach a steady state.

[0072] Open the vacuum solenoid valve 5 and vacuum pump 6, connect the transfer solenoid valve 7 to the exhaust pipe (or gas collection chamber 9, depending on whether it is necessary to collect the gas released from the liquid phase), and close the vacuum solenoid valve 5 and vacuum pump 6 when the pressure reaches the specified value by monitoring the pressure sensor 3.

[0073] When degassing is determined to be complete, open the pressure relief solenoid valve 4 to release pressure from the degassing chamber 8; open the outlet solenoid valve 15 and the gear pump 13 to discharge the liquid after degassing. Otherwise, repeatedly pump air until degassing is complete.

[0074] In summary, this embodiment integrates the principles of vacuum degassing, ultrasonic degassing, and magnetic stirring, making it suitable for vacuum degassing of various media such as high-viscosity liquids, transformer oil, and water-based liquids. Magnetic stirring solves the problems associated with vacuum degassing and ultrasonic degassing when degassing high-viscosity liquids, compensating for the shortcomings of individual technical approaches for degassing liquids of different viscosities. Furthermore, by using a vibratory viscometer to detect the liquid viscosity and adaptively setting the frequency of the ultrasonic generator and the rotation speed of the magnetic stir bar based on the viscosity, the degassing efficiency is greatly improved. Moreover, the use of non-contact magnetic stirring and ultrasonic degassing avoids liquid contamination and improves overall airtightness and vacuum degassing efficiency.

[0075] When referencing drawings, new features are explained. To avoid redundant references to drawings that would make the description less concise, features already described will not be referenced again on the drawings if the description is clear.

[0076] The purpose of the above embodiments is to reproduce and derive the technical solution of the present invention by way of example, and to fully describe the technical solution, purpose and effect of the present invention. The purpose is to enable the public to have a more thorough and comprehensive understanding of the disclosure of the present invention, and not to limit the scope of protection of the present invention.

[0077] The above embodiments are not an exhaustive list based on the present invention, and there may be many other embodiments not listed. Any substitutions and improvements made without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A vacuum degassing method, characterized in that, include: A vacuum pump is used to evacuate the degassing chamber; The liquid to be degassed is allowed to flow into the degassing chamber and its viscosity is measured. The rotation speed of the magnetic stir bar and the frequency of the ultrasonic generator are set according to the viscosity. The magnetic stir bar and the ultrasonic generator are controlled to perform degassing in a coordinated manner. The magnetic stir bar is installed in the degassing chamber and cooperates with the magnetic stir bar outside the degassing chamber. The ultrasonic generator is installed outside the degassing chamber. When the magnetic stir bar rotates, the liquid to be degassed passes evenly through the ultrasonic waves generated by the ultrasonic generator. When the preset evacuation conditions are met, the magnetic stirrer and the ultrasonic generator are turned off. After a preset time of settling, the degassing chamber is evacuated and the magnetic stirrer and the ultrasonic generator are controlled again to perform coordinated degassing until the preset completion conditions are met, and the degassed liquid is obtained. The step of setting the rotation speed of the magnetic stirrer and the frequency of the ultrasonic generator according to the viscosity includes: The viscosity range of the liquid is divided into a low viscosity range, a medium viscosity range, and a high viscosity range. A first speed range, a second speed range, and a third speed range are set for the low viscosity range, the medium viscosity range, and the high viscosity range, respectively, and the first speed range, the second speed range, and the third speed range are arranged from large to small. When the viscosity is in the low viscosity range, the rotation speed is limited to the first rotation speed range; when the viscosity is in the medium viscosity range, the rotation speed is limited to the second rotation speed range; when the viscosity is in the high viscosity range, the rotation speed is limited to the third rotation speed range, and the frequency is limited to a preset frequency range. The first speed range is above 1000 rpm, the second speed range is 300 rpm to 1000 rpm, the third speed range is 100 rpm to 300 rpm, and the frequency range is 20 kHz to 30 kHz. The low viscosity range is less than 80 cP, the medium viscosity range is 80 cP to 500 cP, and the high viscosity range is greater than 500 cP. The vacuum pump is connected to a gas collection chamber. The preset pumping condition is a preset time interval. Determining whether the preset completion condition has been met includes: Obtain the current gas volume collected in the gas collection chamber, subtract it from the previous gas volume to obtain the gas volume increment; When the ratio of the gas volume increment to the total gas volume in the gas collection chamber is less than a preset threshold, it is determined that the preset completion condition has been met; otherwise, it is determined that the preset completion condition has not been met. or, The preset air extraction condition is that the pressure in the degassing chamber reaches a preset value, and the preset completion condition is that the pressure in the degassing chamber does not reach the preset value even after a preset time has elapsed.

2. The vacuum degassing method as described in claim 1, characterized in that, A transducer is attached to the outer wall of the degassing chamber, and the transducer is connected to the ultrasonic generator.

3. The vacuum degassing method as described in claim 1, characterized in that, The vacuum pump is connected to a transfer solenoid valve, which is connected to the gas collection chamber or the exhaust pipe.

4. The vacuum degassing method as described in claim 1, characterized in that, When the liquid to be degassed flows into the degassing chamber, a vibratory viscometer is used to detect the viscosity of the liquid.

5. A vacuum degassing device, characterized in that, For performing the vacuum degassing method as described in any one of claims 1-4, the vacuum degassing apparatus comprises: The system includes a degassing chamber, a magnetic stirrer, an ultrasonic generator, a transducer, a magnetic stir bar, a vibratory viscometer, and a vacuum pump. One end of the vibratory viscometer extends into the degassing chamber to detect the viscosity of the liquid. The magnetic stirrer and the ultrasonic generator are installed outside the degassing chamber. The transducer is attached to the outer wall of the degassing chamber and connected to the ultrasonic generator. The vacuum pump is connected to the inner cavity of the degassing chamber. The magnetic stir bar is installed inside the degassing chamber and works in conjunction with the magnetic stirrer. A control device electrically connected to the magnetic stirrer, ultrasonic generator, and vibratory viscometer is also provided. This control device is used to set the rotational speed of the magnetic stir bar and the frequency of the ultrasonic generator according to the viscosity, controlling the magnetic stir bar and the ultrasonic generator to perform coordinated degassing.

6. The vacuum degassing apparatus as described in claim 5, characterized in that, It is also equipped with a transfer solenoid valve, a gas collecting chamber and an exhaust pipe. The transfer solenoid valve is connected to the vacuum pump, the gas collecting chamber or the exhaust pipe is connected to the transfer solenoid valve, and / or, a heating device is installed at the bottom of the degassing chamber.

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