Leak testing device
By designing a conical sidewall structure in the leak testing device, the test liquid can be uniformly wetted into the membrane, thus solving the problem of unstable membrane leakage rate and improving the accuracy and stability of gas leak detection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- INFICON INC
- Filing Date
- 2021-05-25
- Publication Date
- 2026-05-19
AI Technical Summary
In existing leak testing devices, the membrane leakage rate is greatly affected by the degree of liquid wetting, resulting in an unstable leakage rate and making it difficult to accurately detect the amount of gas leakage.
Design a leak testing device in which a membrane is placed inside a base, and the distance between the inner sidewall of the membrane and the base gradually decreases to form a conical structure. Gravity is used to make the test liquid uniformly wet the membrane, preventing the liquid from directly contacting the membrane.
A stable leakage rate of the membrane was achieved, ensuring uniform distribution of gas or liquid components and improving the accuracy and stability of gas leak detection.
Smart Images
Figure CN115702332B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a test leak device for testing the functionality of a gas leak detection device and for calibrating a gas leak detection device. Background Technology
[0002] Gas leak detection devices typically include an evacuable test chamber in which a test object filled with gas or liquid is placed. The test chamber is connected to a gas analyzer that analyzes gas extracted from the test chamber to detect leaking gas that may have entered the test chamber through a leak point on the test object, or to detect liquid that has escaped through a leak point and evaporated. Of particular importance is the ability to infer the size of the leak point from the amount of leaking gas detected. For this purpose, a leak tester is used, containing a predetermined quantity of a known test gas or test liquid and providing a leak point with a known size and / or known permeability to the contained liquid. Leak testers are commonly used to test the functionality of gas leak detection devices and to calibrate them.
[0003] The leakage point of a leak test device is usually designed as a membrane, and its leakage rate depends on the permeability of the membrane body to the corresponding test gas or test liquid, the membrane temperature, the temperature and vapor pressure of the test gas / test liquid, the degree of wetting on the inner / liquid side of the membrane, and the ventilation on the outlet side of the membrane (i.e., the outer side of the leak test device).
[0004] For example, EP 2 447 694 B1 describes a liquid-filled test leak from which gas or vapor or liquid components transported by gas escape. The gas or vapor or liquid components transported by gas escaping from the test leak are formed by the liquid due to its specific vapor pressure or by permeation through a solid layer of a membrane.
[0005] The leakage rate in membrane testing depends on whether and to what extent the inner side of the membrane is wetted by liquid. In this respect, whether the membrane is in direct contact with the liquid or only in contact with liquid vapor can significantly affect the leakage rate. To obtain a stable leakage rate, liquid contact with the membrane should be prevented, or it should be ensured that only liquid vapor contacts the membrane.
[0006] DE 10 2014 200 907 B4 describes a reference exhaust system having a gas storage tank containing a liquid or a liquid mixture. A transport vacuum chamber surrounds the gas storage tank. The chamber pressure in the transport vacuum chamber is less than 10 kPa. Summary of the Invention
[0007] The object of the present invention is to provide an improved leak testing device comprising a membrane having a stable leak rate.
[0008] According to the present invention, a test leak device includes a base, a cover, and at least one sidewall connecting the base and the cover, the base, cover, and sidewall forming an internal space capable of being filled with a test gas or a test liquid. The test leak device has a membrane permeable to components of the test gas or test liquid, allowing the test gas or test liquid components to escape from the test leak device through the membrane.
[0009] The invention is characterized in that the membrane is disposed in the base of the leak test device, and the opposing portions of the inner sides (facing the internal space) of the sidewalls are spaced further apart in the region of the cover than in the region of the base. Therefore, the distance between the opposing portions of the sidewalls decreases from the cover to the base, and thus the test liquid contained in the internal space flows towards the membrane along the portions of the sidewalls under the influence of gravity.
[0010] As an alternative, a groove can be formed on the base of the leak test device, wherein the groove has an inner side facing the interior space, and the opposing portions of the inner side are spaced further apart in the area of the cover than in the area of the base. In other words, the distance between the opposing portions of the inner side decreases from the top (from the cover) to the bottom (towards the base).
[0011] The distance between opposing portions of the inner sides (facing the interior space) of the sidewalls or grooves preferably decreases gradually from the cover towards the base. The inner sides may be cylindrical around the interior space, and in particular, taper conically towards the membrane. Here, it is particularly advantageous if, in the base region, the inner sides are connected to the membrane or to a through-hole containing the membrane formed on the base.
[0012] In this case, the through-hole and / or membrane can be formed into a cylinder and have a circular surface facing the interior space, with the inner side of the sidewall or groove connected to the outer edge of the circular surface.
[0013] The base, located away from the lower side of the internal space, i.e., when the test leak device is placed at the bottom of the test chamber of the gas leak detection device, advantageously has at least one gasket on its outer side facing the bottom of the test chamber. This gasket prevents the lower side of the base from contacting the bottom of the test chamber when the test leak device is contained within the test chamber. The gasket facilitates the entry of the test liquid or vapor from the test leak device through the membrane into the test chamber, ensuring uniform distribution of the test liquid or vapor within the test chamber in the area between the test leak device and the bottom of the test chamber.
[0014] The leak testing device preferably includes a filling port that is closed by a valve.
[0015] The advantage of this invention is that, because the distance between the inner opposing portions decreases towards the through-holes on the membrane or base, the membrane is uniformly wetted by the test liquid. Gravity causes the test liquid to move towards the base within the leak test device, and thus towards the membrane. Therefore, the storage capacity for the test liquid, enclosed by the base, cover, and sidewalls of the leak test device, gradually decreases from top to bottom towards the membrane. Attached Figure Description
[0016] The embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. In the drawings:
[0017] Figure 1 This is a cross-sectional view of the first embodiment of the leak testing device; and
[0018] Figure 2 This is a cross-section of a second embodiment of the leak testing device. Detailed Implementation
[0019] In both embodiments, the leak test device has a base 12, which is entirely surrounded by a circumferential sidewall 14 that projects laterally from the outer edge of the base. A cover 16 is fluid-tightly connected to the sidewall, thereby fluid-tightly enclosing the base 12, sidewall 14, and cover 16 to form an internal space 20. Therefore, the internal space 20 can be filled with a test fluid, i.e., a test gas or a test liquid.
[0020] A through-hole 22 is formed on the base 12, which connects the internal space 20 to the external environment of the test leak device. A membrane 24 is inserted into the through-hole, which is configured to be permeable to the components of the test or test liquid. Therefore, the test liquid contained in the internal space 20 can only escape from the test leak device through the membrane 24.
[0021] The sidewall 14 is configured as a cylindrical annular protrusion from the outer circumference of the base 12, with its inner side 26 forming a cone that gradually tapers toward the membrane 24 and the through hole 22. At its lower end facing the base 12, the cone has a central opening that leads to the through hole 22 and connects to the membrane 24.
[0022] Since the base 12 and the side wall 14 are integrally connected, the cone on the inner side 26 can also be regarded as the groove of the base 12.
[0023] Due to gravity, and because the diameter of the internal space 20 gradually decreases towards the through-hole 22 and the membrane 24, the test liquid contained in the internal space 20 flows along the inner side 18 into the through-hole 22 and then into the membrane 24. Therefore, as long as the test leak device 10 is upright on the substrate, such as the bottom 32 of the test chamber 34 of a gas leak detection device (not fully shown in the figure), the membrane will be uniformly wetted by the test liquid.
[0024] exist Figure 1 In this embodiment, the lower side 28 of the base 12 is provided with a plurality of gaskets 30 in the form of protrusions 30, which protrude downward from the lower side 28. When the test leak device 10 is placed at the bottom of the test chamber, these gaskets 30 create a distance between the lower side 28 and the bottom of the test chamber. In this figure, the bottom of the test chamber is identified by reference numeral 32, and the test chamber is identified by reference numeral 34.
[0025] In one of the gasket 30 areas, the base 12 has a filling port 36 that connects the internal space 20 to the external environment of the test leak device 10 and is closed by a valve 38. The valve 38 is configured to allow test liquid to enter the internal space 20 from the outside, but to prevent it from escaping from the internal space 20 to the outside through the filling port 36.
[0026] exist Figure 2 In one embodiment, the lower side 28 of the base 12 has a plate-like shape concentrically surrounding the through-hole 22, without a separate gasket 30 integrally formed with the base. The membrane 24 is inserted into the lower end of the through-hole 22. The through-hole 22 leads to the internal space 20 and has a smaller diameter compared to the membrane 24. The through-hole 22 is concentrically surrounded by a hole 40, into which a fastening element for securing the membrane 24 is inserted in the form of a screw. In a second embodiment, the fastening element is secured in the hole by a conventional screw connection with threaded engagement. The screw head, inserted upwards from below into the hole 40, protrudes downwards. Figure 2 (Not shown in the image) Extends beyond the lower side 28 of the base 12, thereby forming a gasket that is equivalent to the gasket 30 of the first embodiment.
Claims
1. A test leak device (10) for testing the function of a gas leak detection device and calibrating the gas leak detection device, the gas leak detection device having an evacuable test chamber (34) for receiving a test object and / or the test leak device (10), wherein, The test leak device (10) has a base (12), a cover (16) and at least one sidewall (14) connecting the base (12) and the cover (16), which encloses an internal space (20) that can be filled with test gas or test liquid. Its features are, The base (12) has a membrane (24) that is permeable to the components of the test gas or the test liquid. The opposing portions of the inner sides (18) of the sidewalls (14) facing the interior space (20) are more distant from each other in the region of the lid than in the region of the base, and The inner side (18) of the sidewall (14) is cylindrically surrounding the inner space (20) and tapers conically toward the membrane (24).
2. The leak testing device (10) according to claim 1, characterized in that, The distance between the opposing portions of the inner side (18) of the sidewall (14) facing the interior space (20) gradually decreases from the cover (16) to the base (12).
3. The leak testing device (10) according to claim 1 or 2, characterized in that, In the region of the base, the inner side of the sidewall (14) is connected to a through hole (22) including the membrane (24).
4. The leak testing device (10) according to claim 3, characterized in that, The through hole (22) is formed in a cylindrical shape and has a circular surface facing the interior space, the outer edge of which is connected to the inner side of the sidewall (14).
5. The leak testing device (10) according to claim 1 or 2, characterized in that, The base (12) has at least one gasket (30) on its lower side (28) facing away from the interior space (20) to prevent the lower side (28) of the base from contacting the bottom (32) of the test chamber when the test leakage device is included in the test chamber.
6. The leak testing device (10) according to claim 1 or 2, characterized in that, The test leak device has a filling port (36) that is closed by a valve (38).
7. The leak testing device (10) according to claim 1 or 2, characterized in that, The base (12) and the sidewall (16) are formed as a single piece, and the inner side (18) is formed as a groove of the single piece.
8. A test leak device (10) for testing the function of a gas leak detection device and calibrating the gas leak detection device, the gas leak detection device having an evacuable test chamber (34) for receiving a test object and / or the test leak device (10), wherein, The test leak device (10) has a base (12), a cover (16) and at least one sidewall (14) connecting the base (12) and the cover (16), enclosing an internal space (20) capable of being filled with test gas or test liquid. Its features are, The base (12) has a membrane (24) that is permeable to the components of the test gas or the test liquid. The base has a groove with an inner side (18) facing the interior space (20), wherein the opposing portions of the inner sides (18) are further apart in the region of the cover than in the region of the base. The inner side (18) of the sidewall (14) is cylindrically surrounding the inner space (20) and tapers conically toward the membrane (24).
9. The leak testing device (10) according to claim 8, characterized in that, The distance between the opposing portions of the inner side (18) of the sidewall (14) facing the interior space (20) gradually decreases from the cover (16) to the base (12).
10. The leak testing device (10) according to claim 8 or 9, characterized in that, In the region of the base, the inner side of the sidewall (14) is connected to a through hole (22) including the membrane (24).
11. The leak testing device (10) according to claim 10, characterized in that, The through hole (22) is formed in a cylindrical shape and has a circular surface facing the interior space, the outer edge of which is connected to the inner side of the sidewall (14).
12. The leak testing device (10) according to claim 8 or 9, characterized in that, The base (12) has at least one gasket (30) on its lower side (28) facing away from the interior space (20) to prevent the lower side (28) of the base from contacting the bottom (32) of the test chamber when the test leakage device is included in the test chamber.
13. The leak testing device (10) according to claim 8 or 9, characterized in that, The test leak device has a filling port (36) that is closed by a valve (38).
14. The leak testing device (10) according to claim 8 or 9, characterized in that, The base (12) and the sidewall (16) are formed as a single piece, and the inner side (18) is formed as a groove of the single piece.