A filtering device for sealing fluorine oil used in leak detection test

Abstract

The application discloses a filtering device for sealing and leak detection test fluorine oil, which comprises a flow director, a buffer oil storage tank and a filtering assembly connected in series; the filtering assembly comprises a filter core group, a differential pressure measurement assembly and an optical monitoring assembly; the differential pressure measurement assembly comprises a differential pressure sensor body and a pressure lead pipe; the differential pressure sensor body is connected in parallel to both ends of the filter core group through the pressure lead pipe; the filter core group comprises at least two filtering units connected in series; the optical monitoring assembly comprises a laser emitting unit, a transparent detection pipe and a photoelectric receiver; the transparent detection pipe is arranged between the two filtering units; the laser emitting unit and the photoelectric receiver are arranged on both sides of the transparent detection pipe; the laser emitting unit emits laser which passes through the transparent detection pipe and is received by the photoelectric receiver. The multi-stage filtering is more efficient; the differential pressure measurement assembly can indirectly monitor the filter core state; and the optical monitoring assembly can monitor the fluorine oil.

Description

Technical Field

[0001] This invention relates to the field of testing technology, and in particular to a filtration device for fluorinated oil used in leak detection tests. Background Technology

[0002] In the fields of integrated circuits, aerospace, and military applications, the helium-filled fluorinated oil leak detection method is a commonly used and highly accurate method for sealing testing. This method requires immersing the workpiece in a special fluorinated oil and observing whether bubbles are generated to determine its sealing performance.

[0003] Currently, the fluorinated oil used for leak detection is expensive and needs to be recycled repeatedly. During the recycling process, the fluorinated oil is easily contaminated by solid particulate impurities such as dust in the environment and residual contaminants on the workpiece. Contaminated fluorinated oil can cause a series of serious problems: 1) Tiny impurity particles may themselves become gas nuclei, generating false bubbles and leading to misjudgments; 2) Contamination will change the physicochemical properties of the fluorinated oil, affecting its sensitivity to minor leaks and reducing detection reliability; 3) Impurities will wear down and clog valves, pipelines, and other components in precision leak detection equipment, shortening equipment life and increasing maintenance costs.

[0004] Currently, there is a lack of dedicated, efficient, and reliable filtration solutions for this application scenario. Ordinary filtration devices may suffer from poor compatibility with fluorinated oils (leading to secondary oil contamination), insufficient sealing (causing leaks and air ingress), low filtration efficiency, and inconvenient filter replacement. Therefore, there is an urgent need to develop a fluorinated oil filtration device specifically designed for leak detection testing to ensure oil purity, guarantee the accuracy of leak detection results, and reduce operating costs. Summary of the Invention

[0005] In view of the above-mentioned shortcomings in the current fluorinated oil filtration process for sealing leak testing, the present invention provides a filtration device for fluorinated oil in sealing leak testing, which can improve the reliability and efficiency of the filtration device.

[0006] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions: A filtration device for fluorinated oil in a leak detection test includes a flow guide, a buffer tank, and a filter assembly connected in series. The filter assembly includes a filter element group, a differential pressure measurement component, and an optical monitoring component. The differential pressure measurement component includes a differential pressure sensor body and a pressure tapping tube. The differential pressure sensor body is connected in parallel at both ends of the filter element group via the pressure tapping tube. The filter element group includes at least two stages of filter units connected in series. The optical monitoring component includes a laser emitting unit, a transparent detection tube, and a photoelectric receiver. The transparent detection tube is disposed between two filter units. The laser emitting unit and the photoelectric receiver are disposed on both sides of the transparent detection tube. The laser emitted by the laser emitting unit passes through the transparent detection tube and is received by the photoelectric receiver. The device also includes a control unit. The differential pressure sensor body, the laser emitting unit, and the photoelectric receiver are electrically connected to the control unit.

[0007] According to one aspect of the present invention, the laser emitting unit is a multi-wavelength laser, including a red light emitting unit, a green light emitting unit, and a blue light emitting unit.

[0008] According to one aspect of the present invention, the photoelectric receiver includes a front receiver and a side receiver; the front receiver is on the same straight line as the laser emitting unit and the transparent detection tube; the side receiver is at a right angle to the front receiver.

[0009] According to one aspect of the present invention, the differential pressure sensor body includes a high-pressure chamber and a low-pressure chamber; a transmitting diaphragm is disposed between the high-pressure chamber and the low-pressure chamber; the pressure tapping tube includes a high-pressure tapping tube and a low-pressure tapping tube; the high-pressure chamber is connected to the inlet end of the filter element assembly through the high-pressure tapping tube; the low-pressure chamber is connected to the outlet end of the filter element assembly through the low-pressure tapping tube.

[0010] According to one aspect of the present invention, the filter cartridge assembly includes a primary filter cartridge and a secondary filter cartridge; the transparent detection tube is disposed between the primary filter cartridge and the secondary filter cartridge.

[0011] According to one aspect of the present invention, the primary filter element is a stainless steel mesh filter element; the secondary filter element is a PTFE pleated filter element.

[0012] According to one aspect of the present invention, the optical monitoring component is encapsulated within a housing; the inner wall of the housing is provided with an anti-glare structure or the inner surface is coated with an anti-glare coating.

[0013] According to one aspect of the present invention, a nitrogen channel is provided above the buffer oil storage tank.

[0014] According to one aspect of the invention, the outlet end of the filter assembly is connected to an outlet pipe; a valve is provided on the outlet pipe; the valve is electrically connected to a control unit.

[0015] Advantages of implementing this invention: It is equipped with a buffer oil storage tank to temporarily store fluorinated oil and ensure a stable filtration process; it has two-stage filter elements for more efficient and better filtration; differential pressure sensors at both ends of the filter element assembly can monitor the filter element status for easy maintenance and timely replacement; and an optical monitoring component is installed to monitor the fluorinated oil status. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a fluorinated oil filtration device for leak detection testing according to the present invention; Figure 2 This is a schematic diagram of the structure of the optical monitoring component described in this invention; Figure 3 This is a structural block diagram of a fluorinated oil filtration device for leak detection testing according to the present invention.

[0018] Legend: 1. Flow guide; 2. Buffer oil tank; 21. Nitrogen channel; 3. Valve; 41. Primary filter element; 42. Secondary filter element; 5. Differential pressure sensor body; 6. Pressure tapping tube; 7. Laser emitting unit; 71. Red light emitting unit; 72. Green light emitting unit; 73. Blue light emitting unit; 8. Transparent detection tube; 9. Photodetector; 91. Front receiver; 92. Side receiver. Detailed Implementation

[0019] 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.

[0020] like Figure 1 , Figure 2 and Figure 3As shown, a filtration device for fluorinated oil used in a leak detection test includes a flow guide 1, a buffer oil tank 2, and a filter assembly connected in series. The filter assembly includes a filter element group, a differential pressure measurement component, and an optical monitoring component. The differential pressure measurement component includes a differential pressure sensor body 5 and a pressure tapping tube 6. The differential pressure sensor body 5 is connected in parallel at both ends of the filter element group via the pressure tapping tube 6. The filter element group includes at least two stages of filter units connected in series. The optical monitoring component includes a laser emitting unit 7, a transparent detection tube 8, and a photoelectric receiver 9. The transparent detection tube 8 is disposed between two filter units. The laser emitting unit 7 and the photoelectric receiver 9 are disposed on both sides of the transparent detection tube 8. The laser emitted by the laser emitting unit 7 passes through the transparent detection tube 8 and is received by the photoelectric receiver 9. The device also includes a control unit. The differential pressure sensor body 5, the laser emitting unit 7, and the photoelectric receiver 9 are electrically connected to the control unit.

[0021] The differential pressure sensor body 5 includes a high-pressure chamber and a low-pressure chamber; a transmitting diaphragm is disposed between the high-pressure chamber and the low-pressure chamber; the pressure tapping tube 6 includes a high-pressure tapping tube 6 and a low-pressure tapping tube 6; the high-pressure chamber is connected to the inlet end of the filter element group through the high-pressure tapping tube 6; the low-pressure chamber is connected to the outlet end of the filter element group through the low-pressure tapping tube 6. The principle of differential pressure sensor for measuring differential pressure is as follows: the pressure of the liquid on both sides acts on both ends of the transmitter diaphragm. The pressure difference on both sides will cause the diaphragm to deform, and the resistance value of the internal piezoresistive bridge will change, thereby outputting a corresponding electrical signal. After filtering, temperature compensation and amplification, the electrical signal is output as a standard signal in the form of 0-5V or 4-20mA.

[0022] The filter cartridge assembly includes a primary filter cartridge 41 and a secondary filter cartridge 42; the primary filter cartridge 41 is a stainless steel mesh filter cartridge; the secondary filter cartridge 42 is a PTFE pleated filter cartridge; it can filter larger mechanical impurities (larger solid particles and colloidal substances) in fluorinated oil, and can perform effective preliminary filtration to prevent large particles from clogging and damaging the secondary filter cartridge 42; the pressure difference across the filter cartridge assembly will change significantly when the filter cartridge fails and becomes clogged. Compared with the normal operating condition, the pressure difference across the two ends will be greater. Therefore, this value can indirectly reflect the working status of the filter cartridge and provide a basis for determining the replacement of the filter cartridge.

[0023] The transparent detection tube 8 is located between the primary filter element 41 and the secondary filter element 42. The fluorinated oil in this position can reflect the state of the fluorinated oil before it has undergone fine filtration.

[0024] The laser emitted by laser emitting unit 7 passes through transparent detection tube 8 and the fluorinated oil within it, undergoing scattering and absorption. The concentration of particulate matter in the fluorinated oil affects the degree of laser absorption and scattering. When photodetector 9 receives the laser and converts it into an electrical signal, the signal intensity changes with the cleanliness of the fluorinated oil. Therefore, this mechanism can be used to monitor the cleanliness of the fluorinated oil and thus determine its quality. In practical applications, the optical monitoring components are encapsulated in a housing; the inner wall of the housing is provided with an anti-glare structure or the inner surface is coated with an anti-glare coating, which can reduce the interference of light reflection on the monitoring results.

[0025] In addition to normal wear and tear during use, fluorinated oil may introduce various impurities, such as solid particulate matter (e.g., metal powder, rust dust, grinding dust, pipeline corrosion particles, filter powder, seal debris, carbide particles, etc.), gaseous impurities (e.g., water vapor, flux vapors, etc.), liquid suspended impurities (in extreme cases, mixing with engine oil, cutting oil, rust inhibitors, etc.), and small molecule impurities (trace amounts of chemical organic matter, acidic volatiles, small molecules from the thermal decomposition of the fluorinated oil itself at high temperatures, etc.). These impurities have different effects on the optical properties of fluorinated oil. For example, solid particulate matter mainly causes obstruction and scattering, which will make the fluorinated oil appear grayish and dark, and reduce its transparency. When laser is transmitted, it will show a steady decrease in light intensity without any color change. Water vapor and similar impurities will cause microemulsion suspension, resulting in an overall milky white and turbid appearance. When laser is transmitted, it will show a significant decrease in light intensity, large signal fluctuations, and turbidity. Liquid suspended impurities will cause the oil to be slightly foggy, hazy and opaque, and the color will turn yellow and gradually darken. Small molecule impurities will make the fluorinated oil appear clear and transparent overall, but with a light yellow color. To distinguish the aforementioned impurities, the laser emitting unit 7 is a multi-wavelength laser, including a red light emitting unit 71, a green light emitting unit 72, and a blue light emitting unit 73, capable of detecting the degree of absorption of impurities by different wavelengths of laser light. In addition, the photodetector 9 includes a front receiver 91 and a side receiver 92; the front receiver 91 is on the same straight line as the laser emitting unit 7 and the transparent detection tube 8; the side receiver 92 is at a right angle to the front receiver 91, wherein the side receiver is used to detect lateral scattered light, thereby detecting the degree of scattering of laser light by impurities; In practical applications, the transmitted light signal is mainly analyzed from the following perspectives: total light intensity variation, lateral scattering degree, signal stability, and absorption degree of light at each wavelength. Specifically: Transmission attenuation rate = (New oil reference transmittance - forward transmittance) / New oil reference transmittance; Scattering ratio = Lateral transmittance / Frontal transmittance; Spectral attenuation difference = Blue light transmission attenuation rate - Red light transmission attenuation rate.

[0026] Among them, the forward light transmission intensity is the light intensity data detected by the front receiver 91; the lateral light transmission intensity is the light intensity data detected by the side receiver 92; the new oil reference light transmission intensity is the forward light transmission intensity of the new fluorinated oil in the setting; the blue light transmission attenuation rate is the transmission attenuation rate of blue laser light detected alone, and the red light transmission attenuation rate is the transmission attenuation rate of red laser light detected alone (because when the color of fluorinated oil changes, it mainly appears yellow or brown, and its absorption rate of blue light is the highest, so the blue light transmission attenuation rate is the most significant); in addition, the sampling values ​​of the photoelectric receiver 9 need to be calculated in real time to determine the signal fluctuation. When the above data show specific changes, the corresponding impurity situation can be preliminarily judged. For example, it can be divided into the following four working conditions: 1. Solid particulate matter: the light intensity attenuation of each wavelength increases synchronously, the difference in spectral attenuation is very small, the scattering ratio is moderate, and the signal fluctuation is small; 2. Oil containing water: micro water droplets have a strong scattering effect on the laser, the scattering ratio increases sharply, the light transmission intensity decreases, and the signal fluctuation value is large due to the random movement of water droplets; 3. Other oils or small molecule impurities are mixed in the oil: the blue light attenuation is much greater than that of red light, the difference in spectral attenuation is significantly larger, the scattering ratio is basically unchanged, and the signal fluctuation is small; 4. Normal and usable: all values ​​are within the normal range, and the signal has no fluctuation. Therefore, the influence of the above-mentioned types of impurities on the optical properties of fluorinated oil can be combined to judge the oil quality. In addition, further distinguishing between small molecule impurities and liquid suspended impurities requires analysis of the change curves of various values. If it is a small molecule impurity, it will often selectively absorb short wavelengths, the blue light attenuation is obvious, the attenuation curve is smooth, and the refractive index change is also slow and smooth. However, when other types of oils are mixed in the fluorinated oil, the changes in its various optical parameters are often abrupt in a short period of time.

[0027] Furthermore, the pressure difference change across the filter element and laser transmission detection can be combined to analyze the filter element's usage status and the oil quality. For example, when the pressure difference increases and the light transmittance decreases, it indicates an increase in large particulate impurities and severe contamination, requiring filter element replacement, and the fluorinated oil may also need to be replaced. When the pressure difference is normal, but the light transmittance decreases significantly and the signal fluctuates greatly, it indicates that the fluorinated oil may contain a lot of water and requires dehydration treatment. When the pressure difference is normal, the laser attenuation is stable but the blue light attenuates, the fluorinated oil may contain a lot of small molecule impurities, requiring further evaluation.

[0028] A nitrogen channel 21 is provided above the buffer oil storage tank 2, which is connected to a nitrogen source. In the factory, it can be connected to the plant's nitrogen source. Introducing nitrogen into the buffer oil storage tank 2 can maintain a certain pressure in the filtration passage and accelerate the filtration process to a certain extent. In addition, introducing nitrogen can also remove air from the pipeline, which plays a certain protective role for the fluorinated oil. Furthermore, a control switch is provided on the nitrogen channel 21, which is also connected to the control unit.

[0029] The outlet end of the filter assembly is connected to an outlet pipe; a valve 3 is installed on the outlet pipe; the valve 3 is electrically connected to the control unit.

[0030] It also includes a status indicator component; the status indicator component is electrically connected to the control unit and includes a status indicator light and an electronic display screen. The indicator light can serve as a prominent reminder when the filter element is clogged and fails, while the electronic display screen can intuitively display data such as pressure difference and fluorinated oil cleanliness.

[0031] Advantages of implementing this invention: It is equipped with a buffer oil storage tank to temporarily store fluorinated oil and ensure a stable filtration process; it has two-stage filter elements for more efficient and better filtration; differential pressure sensors at both ends of the filter element assembly can monitor the filter element status for easy maintenance and timely replacement; and an optical monitoring component is installed to monitor the fluorinated oil status.

[0032] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A filtration device for fluorinated oil used in leak detection tests, characterized in that, The system includes a flow guide (1), a buffer oil storage tank (2), and a filter assembly connected in series. The filter assembly includes a filter element group, a differential pressure measurement assembly, and an optical monitoring assembly. The differential pressure measurement assembly includes a differential pressure sensor body (5) and a pressure tapping tube (6). The differential pressure sensor body (5) is connected in parallel at both ends of the filter element group through the pressure tapping tube (6). The filter element group includes at least two stages of filter units connected in series. The optical monitoring assembly includes a laser emitting unit (7), a transparent detection tube (8), and a photoelectric receiver (9). The transparent detection tube (8) is located between two filter units. The laser emitting unit (7) and the photoelectric receiver (9) are located on both sides of the transparent detection tube (8). The laser emitted by the laser emitting unit (7) passes through the transparent detection tube (8) and is received by the photoelectric receiver (9). The system also includes a control unit. The differential pressure sensor body (5), the laser emitting unit (7), and the photoelectric receiver (9) are electrically connected to the control unit.

2. The filtration device for fluorinated oil used in leak detection testing according to claim 1, characterized in that, The laser emitting unit (7) is a multi-wavelength laser, including a red light emitting unit (71), a green light emitting unit (72), and a blue light emitting unit (73).

3. The filtration device for fluorinated oil used in leak detection testing according to claim 2, characterized in that, The photoelectric receiver (9) includes a front receiver (91) and a side receiver (92); the front receiver (91) is on the same straight line as the laser emitting unit (7) and the transparent detection tube (8); the side receiver (92) is at a right angle to the front receiver (91).

4. The filtration device for fluorinated oil used in leak detection testing according to claim 1, characterized in that, The differential pressure sensor body (5) includes a high-pressure chamber and a low-pressure chamber; a transmitter diaphragm is provided between the high-pressure chamber and the low-pressure chamber; the pressure tapping tube (6) includes a high-pressure tapping tube (6) and a low-pressure tapping tube (6); the high-pressure chamber is connected to the inlet end of the filter element group through the high-pressure tapping tube (6); the low-pressure chamber is connected to the outlet end of the filter element group through the low-pressure tapping tube (6).

5. The filtration device for fluorinated oil used in leak detection testing according to claim 1, characterized in that, The filter assembly includes a primary filter element (41) and a secondary filter element (42); the transparent detection tube (8) is disposed between the primary filter element (41) and the secondary filter element (42).

6. The filtration device for fluorinated oil used in leak detection testing according to claim 5, characterized in that, The primary filter element (41) is a stainless steel mesh filter element; the secondary filter element (42) is a PTFE pleated filter element.

7. The filtration device for fluorinated oil used in leak detection testing according to claim 1, characterized in that, The optical monitoring component is encapsulated in a housing; the inner wall of the housing is provided with an anti-glare structure or the inner surface is coated with an anti-glare coating.

8. The filtration device for fluorinated oil used in leak detection testing according to claim 1, characterized in that, A nitrogen channel (21) is provided above the buffer oil storage tank (2).

9. The filtration device for fluorinated oil used in leak detection testing according to claim 1, characterized in that, The outlet end of the filter assembly is connected to an outlet pipe; a valve (3) is installed on the outlet pipe; the valve (3) is electrically connected to the control unit.

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