A helium detection device and method for porous grid plate parts

Abstract

A helium detection device for porous grid plate parts comprises four parts: a plurality of sealing mechanisms (13), a support plate (12), a connecting bolt (11) and a vacuum chamber. The vacuum chamber comprises a vacuum chamber body (8), a sealing ring (10) and a C-type quick pneumatic joint (9). The vacuum chamber body (8) is a closed cavity. The upper end of the vacuum chamber body (8) is open. One end of the opening is sealed and connected to a flange (81). An annular groove is provided on the upper surface of the flange (81) at a set distance from the opening. The sealing ring (10) is placed in the annular groove. The flange (81) has a plurality of flange through holes (811) on the edge. The opening size of the vacuum chamber body (8) is smaller than that of the grid plate (14) to be tested. A through hole is provided on one side of the vacuum chamber body (8) for sealing connection with the C-type quick pneumatic joint (9). The invention has a simple structure and is easy to operate. It solves the problem of helium sealing detection of porous grid plates, makes sealing detection of porous grid plates convenient, fast and highly accurate, and saves detection working time.

Description

Technical Field

[0001] The invention relates to the technical field of sealing detection, specifically a hole sealing device and method for helium leak detection of porous grid parts. Background Art

[0002] Nuclear reactor pressure vessels can provide the required sealed pressure space environment for the mutual reaction of substances. If a pressure vessel leaks, the pressure difference on both sides of the vessel will cause the gas or liquid in the cooling system to flow out quickly, thus causing a nuclear safety accident and threatening life safety. Therefore, nuclear reactor pressure vessels have high sealing requirements. The leakage index of a small nuclear reactor pressure vessel is 1.66×10 -11 Pa·m 3 / s, which is welded by parts with porous grid structure and thin-walled pipes. In order to ensure the overall sealing of the pressure vessel is reliable, all parts need to be tested for penetration defects before the welding process to ensure that there are no leaks in the parts.

[0003] Existing nondestructive defect detection technologies generally use ultrasonic testing, penetration testing, and leakage testing. Ultrasonic testing is more accurate in qualitatively locating internal defects, penetration testing is more sensitive to near-surface defects, and leakage testing is more accurate for penetrating defects. Helium spraying is generally used for leakage detection. The grid is a flat structure with through holes on it, so helium leak detection cannot be performed directly. Especially for parts with high sealing indicators, specific tooling needs to be designed to seal the holes before sealing testing can be performed. Summary of the invention

[0004] The patent of the present invention provides a helium detection device and method for porous grid plate parts, so that the holes of the grid plate to be tested can be quickly sealed, which is convenient for helium leak detection of the grid plate to be tested.

[0005] A helium detection device for porous grid plate parts, comprising a plurality of sealing mechanisms 13, a support plate 12, a connecting bolt 11 and a vacuum chamber;

[0006] The vacuum chamber includes a vacuum chamber body 8, a sealing ring 10 and a C-type quick pneumatic joint 9. The vacuum chamber body 8 is a closed cavity. The upper end of the vacuum chamber body 8 is open. One end of the opening is sealed and connected to a flange 81. An annular groove is provided on the upper surface of the flange 81 at a set distance from the opening. The sealing ring 10 is placed in the annular groove. The edge of the flange 81 has a plurality of flange through holes 811. The opening size of the vacuum chamber body 8 is smaller than the grid plate 14 to be tested. One side of the vacuum chamber body 8 has a through hole that is sealed and connected to the C-type quick pneumatic joint 9.

[0007] The support plate 12 is a flat plate, and is provided with a plurality of threaded holes 121, the positions of the threaded holes 121 corresponding to the holes on the grid plate 14 to be tested; each threaded hole 121 is fixedly connected to a sealing mechanism 13; and the edge of the support plate 12 also has a plurality of support plate through holes 122;

[0008] During operation, the grid plate 14 to be tested is placed on the flange 81 at the opening of the vacuum chamber 8, so that the grid plate 14 to be tested presses the sealing ring 10; the multiple sealing mechanisms 13 under the support plate 12 are pressed one by one on the holes on the multiple grid plates 14 to be tested, so that all the holes on the grid plates 14 to be tested are sealed; the connecting bolts 11 are used to connect the threaded holes 121 and the flange through holes 811 to fasten the support plate through holes 122 and the flange through holes 811 together, so that the grid plate 14 to be tested seals the vacuum chamber 8.

[0009] The sealing mechanism 13 comprises a pressure block 1, a sealing film 2, a compression spring 3, a resistance strain sensor 4, a positioning block 5 and a hexagon socket polished bolt 6; and a pressure indicator light 7;

[0010] The positioning block 5 is a cylinder, and a groove 51 is provided at the lower end of the cylinder, and the groove 51 is sleeved on the outer side of the pressing block 1; a plurality of through holes 52 are provided at the upper end of the positioning block 5, and the upper part of the through holes is a countersunk hole, and the position and size of the through holes 52 and the countersunk holes at the upper part thereof match the pressing block threaded hole 101 on the pressing block 1; the resistance strain sensor 4 is pasted in the groove 51, and the resistance strain sensor 4 protrudes downward; the power line is connected to the power supply; the countersunk hole depth of the through hole and the countersunk hole 52 is greater than the reserved spacing h between the pressing block 1 and the resistance strain sensor 4; the signal line and the power line of the resistance strain sensor 4 pass through the small through hole 53 in the groove 52 of the positioning block 5 and are connected to the pressure indicator light 7;

[0011] The hexagon socket polished bolt 6 passes through the through hole 52 at the upper end of the positioning block 5 and is assembled with the pressing block threaded hole 101 on the upper surface of the pressing block 1, so that the upper end of the hexagon socket polished bolt 6 falls into the countersunk hole in the through hole 52; the compression spring 3 is installed at the lower part of the hexagon socket polished bolt 6; the depth of the hexagon socket polished bolt 6 is adjusted to maintain a suitable distance between the upper surface of the pressing block 1 and the resistance strain sensor 4; the sealing film 2 is pasted on the lower surface of the pressing block 1, and the material of the sealing film 2 is preferably rubber.

[0012] A stud 54 is disposed on the upper surface of the positioning block 5 on the sealing mechanism 13 , and the positioning block 5 is connected to the threaded hole 121 on the support plate 12 via the stud 54 .

[0013] The sealing ring 10 is an annular rubber ring.

[0014] A method for detecting helium in porous grid plate parts, using a helium detection device for porous grid plate parts according to claim 1 or 2 for detection, characterized in that it comprises the following steps:

[0015] Step 1: Place the grid plate 14 to be tested on the flange 81 at the opening of the vacuum chamber 8, so that the grid plate 14 to be tested presses the sealing ring 10; press the multiple sealing mechanisms 13 under the support plate 12 on the holes on the multiple grid plates 14 to be tested one by one, so that all the holes on the grid plates 14 to be tested are sealed; use the connecting bolts 11 to connect the threaded holes 121 and the flange through holes 811, and fasten the support plate through holes 122 and the flange through holes 811 together, so that the grid plate 14 to be tested seals the vacuum chamber 8;

[0016] Step 2: Connect the C-type quick pneumatic connector 9 on the vacuum chamber to the helium mass spectrometer through a hose; connect the power supply, and when all the pressure indicator lights 7 light up, spray helium above the grid plate 14 to be tested, and use the helium mass spectrometer to test the sealing of the grid plate 14 to be tested. That is, if the helium mass spectrometer detects that there is helium in the vacuum chamber 8, it means that the sealing of the grid plate 14 to be tested does not meet the requirements; if the helium mass spectrometer detects that there is no helium in the vacuum chamber 8, it means that the sealing of the grid plate 14 to be tested is qualified.

[0017] Beneficial Effects

[0018] The invention has a simple structure and is easy to operate, and provides a method for detecting penetration defects of porous grid parts, solves the problem of helium sealing detection of porous grids, makes sealing detection of porous grids convenient, fast and highly accurate, and saves detection work time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 , a cross-sectional view of the sealing mechanism 13 of the present invention mounted on the support plate;

[0020] Figure 2 , a cross-sectional view of the grid plate 14 to be tested in the present invention during testing.

[0021] Among them, 1 is a pressure block, 2 is a sealing film, 3 is a compression spring, 4 is a resistance strain sensor, 5 is a positioning block, 6 is a hexagon socket bare rod bolt, 7 is a pressure indicator light, 8 is a vacuum chamber, 9 is a C-type quick pneumatic connector, 10 is a sealing ring, 11 is a connecting bolt, 12 is a support plate, 13 is a sealing mechanism, 14 is a grid plate to be measured, 51 is a groove, 52 is a through hole, 53 is a small through hole, 54 is a stud, 81 is a flange, 101 is a pressure block threaded hole, 121 is a threaded hole, 122 is a support plate through hole, and 811 is a flange through hole. DETAILED DESCRIPTION

[0022] The device is composed of four parts: a sealing mechanism 13, a support plate 12, a connecting bolt 11 and a vacuum chamber.

[0023] The sealing mechanism 13 of the device includes a pressure block 1, a sealing film 2, a compression spring 3, a resistance strain sensor 4, a positioning block 5, a hexagon socket polished rod bolt 6 and a pressure indicator light 7.

[0024] The outer contour of the pressing block 1 of the sealing mechanism 13 is larger than the hole of the measured part, preferably 3 mm larger than the hole diameter. If the hole to be measured is a stepped hole, the outer contour should be 3 mm larger than the inner hole of the stepped hole.

[0025] A sealing film 2 is pasted on the lower surface of the pressing block 1. The material of the sealing film 2 is preferably rubber, and the thickness of the sealing film 2 is preferably 2 mm.

[0026] The upper surface of the pressing block 1 is processed with a plurality of threaded holes near the edge of the pressing block 1 according to the specifications of the hexagon socket polished bolt 6, and the number of the threaded holes is determined according to the size of the pressing block 1.

[0027] The outer contour of the resistance strain sensor 4 is smaller than the spacing between the threaded holes on the upper surface of the pressing block 1 .

[0028] The positioning block 5 is a cylinder with a groove processed at the lower end of the cylinder. The contour of the groove is the same as the contour of the pressure block 1. There are through holes and countersunk holes at the upper end of the positioning block 5. The positions and sizes of the through holes and countersunk holes are matched with the threaded holes on the pressure block 1. The depth of the countersunk hole should not be less than the reserved spacing between the pressure block 1 and the resistance strain sensor 4.

[0029] There is a small through hole in the groove of the positioning block 5.

[0030] There is a stud at the center position of the upper end of the positioning block 5.

[0031] After the signal line and the power line of the resistance strain sensor 4 pass through the through hole in the groove of the positioning block 5, the resistance strain sensor 4 is pasted in the groove, with the raised side of the resistance strain sensor 4 facing outward.

[0032] The signal line of the resistance strain sensor 4 is connected to the pressure indicator light 7. The power line is connected to the power supply.

[0033] The hexagon socket polished bolt 6 passes through the through hole at the upper end of the positioning block 5 and is assembled with the threaded hole on the upper surface of the pressing block 1, and falls into the countersunk hole.

[0034] The compression spring 3 is mounted on the hexagon socket polished bolt 6 .

[0035] The depth of the hexagon socket polished bolt 6 is adjusted to keep a suitable distance between the pressing block 1 and the resistance strain sensor 4 to form a sealing mechanism 13.

[0036] The support plate 12 of the device is a flat plate with threaded holes evenly distributed on it. The positions of the threaded holes are consistent with the holes of the grid plate to be tested. The threaded hole diameter is the same as the diameter of the stud on the upper end of the positioning block 5. The depth of the threaded hole is not less than the height of the stud on the upper end of the positioning block 5. There is a small through hole near each threaded hole. One side of the support plate 12 should be larger than the grid plate to be tested by more than 20mm.

[0037] Through holes are processed within 20 mm of the outer edge of the support plate 12, and the number of through holes is 6-8 and they are evenly distributed.

[0038] The connecting bolt 11 is composed of a polished bolt and a nut.

[0039] The vacuum chamber of the device is composed of a vacuum chamber 8, a sealing ring 10 and a C-type quick pneumatic connector 9. The vacuum chamber 8 is a closed cavity with an opening at the upper end. The opening size should be about 10mm smaller than the grid plate to be tested. One end of the opening is sealed with a flange, and the width of the flange is not less than 30mm. An annular groove for placing the sealing ring 10 is machined on the flange at a distance of 5mm from the opening, and the depth of the groove is not greater than the radius of the sealing ring 10.

[0040] The sealing ring 10 is an annular rubber ring.

[0041] A through hole is opened on the side wall of the vacuum chamber, and a C-type quick pneumatic connector 9 is welded thereto.

[0042] A through hole is processed on the upper edge of the flange, and the through hole is matched with the through hole at the edge of the support plate 12.

[0043] When in use, the sealing ring 10 is installed in the groove of the vacuum chamber flange, and the grid plate to be inspected is placed on the flange at the opening position of the vacuum chamber. During installation, it is necessary to ensure that the grid plate completely covers the sealing ring 10.

[0044] The studs of the sealing mechanism 13 are installed in the corresponding threaded holes on the support plate 12. After the signal line and the power line on the sealing mechanism 13 pass through the through holes near the threads, the signal line is connected to the pressure indicator light 7, and the indicator light is fixed on the support plate 12 and marked with the indicator light serial number. The indicator light and the support plate 12 can be fixed by bonding.

[0045] If there are multiple holes on the grid plate, repeat the above steps until all holes are blocked.

[0046] The support plate 12 with the sealing mechanism 13 installed is installed above the grid plate to be tested, each sealing mechanism 13 is aligned with a through hole on the grid plate, and the support plate 12 is aligned with the hole on the flange of the vacuum chamber.

[0047] The position of the grid plate is finely adjusted to ensure that all through holes on the grid plate are completely covered by the pressing block 1 of the sealing mechanism 13 .

[0048] After the connecting bolts 11 are passed through the supporting plate 12 and the edge holes of the vacuum chamber flange, the nuts are tightened.

[0049] The C-type quick pneumatic connector 9 on the vacuum chamber is connected to the helium mass spectrometer through a hose.

[0050] Connect the power supply, and when all the pressure indicator lights 7 light up, spray helium above the grid plate, inhale through the C-type quick pneumatic connector 9, and pass into the helium mass spectrometer to test the grid plate sealing.

[0051] Embodiment 1:

[0052] The following is a further description of the device through examples:

[0053] The device provides a hole sealing device for a porous grid plate part during helium leak detection. The device is composed of four parts: a sealing mechanism 13, a support plate 12, a connecting bolt 11 and a vacuum chamber 8.

[0054] The sealing mechanism 13 includes a pressure block 1 , a sealing film 2 , a compression spring 3 , a resistance strain sensor 4 , a positioning block 5 , a hexagon socket polished bolt 6 and a pressure indicator light 7 .

[0055] The vacuum chamber is composed of a vacuum chamber body 8 , a sealing ring 10 and a C-type quick pneumatic connector 9 .

[0056] If you want to detect helium with a porous grid plate part, the outer diameter of the grid plate part is 320mm, the hole diameter is 26mm, and the number of holes is 12.

[0057] The pressing block 1 of the sealing mechanism 13 is a cylindrical metal block with a diameter of 29 mm and a height of 20 mm. Two M3 threaded holes with a depth of 5 mm are symmetrically processed on the upper surface at a distance of 3 mm from the edge.

[0058] The sealing film 2 is a rubber pad with a diameter of 29 mm and a thickness of 2 mm.

[0059] The resistance strain sensor 4 of model AR-N101 is selected, and the outer diameter of the sensor is 10 mm.

[0060] The positioning block 5 is a metal cylinder with a diameter of 43mm and a height of 70mm. A groove with a diameter of 29mm and a depth of 40mm is processed at the lower end of the cylinder. A through hole with a diameter of 3.2mm and a countersunk hole with a diameter of 6mm are provided at the upper end of the groove and the threaded hole position on the pressing block 1. A through hole with a diameter of 2mm is processed on the inner surface of the groove. An M8 stud with a height of 7mm is processed at the center position of the upper end of the positioning block 5.

[0061] After the signal line and power line of the AR-N101 resistance strain sensor 4 pass through the through hole in the groove of the positioning block 5, the resistance strain sensor 4 is pasted in the groove with the raised side of the sensor facing outward, the signal line of the resistance strain sensor 4 is connected to the pressure indicator light 7, and the power line is connected to the power supply.

[0062] An M3 hexagon socket polished bolt 6 is selected to pass through the through hole at the upper end of the positioning block 5 and to be assembled with the M3 threaded hole on the upper surface of the pressing block 1 and fall into the countersunk hole.

[0063] A compression spring 3 with a wire diameter of 0.5 mm is selected and installed on the hexagon socket polished rod bolt 6.

[0064] The depth of the M3 hexagon socket polished bolt 6 is adjusted to keep a suitable distance between the pressing block 1 and the resistance strain sensor 4 to form a sealing mechanism 13.

[0065] The support plate 12 is a flat plate with a diameter of 360 mm and a thickness of 20 mm. Ten M8 threaded holes are evenly distributed on the plate and are consistent with the holes of the grid plate to be tested. The threaded holes have a depth of 10 mm, and a 2 mm through hole is processed near each threaded hole.

[0066] 6 evenly spaced positions with a pitch circle diameter of 340 mm are machined at the upper end of the support plate 12 Through hole.

[0067] The connecting bolt 11 is composed of an M16 bolt with a bare rod and an M16 nut.

[0068] The vacuum chamber body 8 of the vacuum chamber is a closed cavity with an upper opening diameter of 300mm and a height of 90mm. The open end is sealed and connected to a flange with a diameter of 360mm. An annular groove with a width of 5mm and a depth of 2mm is processed at the upper end of the flange at a position of 310mm in the pitch circle diameter, and 6 uniformly distributed grooves are processed at the upper end at a position of 340mm in the pitch circle diameter. Through hole.

[0069] The sealing ring 10 is an annular rubber ring with a diameter of 5 mm.

[0070] A through hole with a diameter of 15.8 mm is opened on the side wall of the vacuum chamber, and a C-type quick pneumatic connector 9 with a model number of PP-40A is welded.

[0071] When in use, the rubber sealing ring 10 is installed in the groove of the vacuum chamber flange, and the grid plate to be inspected is placed on the flange at the opening position of the vacuum chamber. During installation, it is necessary to ensure that the grid plate completely covers the sealing ring 10.

[0072] Install 10 sealing mechanisms 13 on the support plate 12 through M8 studs. After the signal line and power line on the sealing mechanism 13 pass through the through hole near the thread, the signal line is connected to the pressure indicator light 7. The 10 indicator lights are glued and fixed on the support plate 12, and the indicator lights are marked with serial numbers 1-10.

[0073] The support plate 12 with the sealing mechanism 13 installed is installed above the grid plate to be tested, each sealing mechanism 13 is aligned with a through hole on the grid plate, and the support plate 12 is aligned with the hole on the flange of the vacuum chamber.

[0074] The position of the grid plate is finely adjusted to ensure that all through holes on the grid plate are completely covered by the pressing block 1 of the sealing mechanism 13 .

[0075] After the M16 connecting bolt 11 passes through the supporting plate 12 and the edge hole of the vacuum chamber flange, the M16 nut is tightened.

[0076] The C-type quick pneumatic connector 9 on the vacuum chamber is connected to the helium mass spectrometer through a hose.

[0077] Connect the power supply, and when all the pressure indicator lights 7 light up, spray helium above the grid to test the grid sealing.

Claims

1. A helium detection device for a porous grid plate type component, comprising four parts: a plurality of sealing mechanisms (13), a support plate (12), a connecting bolt (11) and a vacuum chamber; The vacuum chamber comprises a vacuum chamber body (8), a sealing ring (10) and a C-type quick pneumatic joint (9); the vacuum chamber body (8) is a closed cavity; the upper end of the vacuum chamber body (8) is open; one end of the opening is sealed and connected to a flange (81); an annular groove is provided on the upper surface of the flange (81) at a set distance from the opening; the sealing ring (10) is placed in the annular groove; a plurality of flange through holes (811) are provided on the edge of the flange (81); the opening size of the vacuum chamber body (8) is smaller than the grid plate (14) to be tested; and a through hole is provided on one side of the vacuum chamber body (8) and is sealed and connected to the C-type quick pneumatic joint (9); The support plate (12) is a flat plate, and is provided with a plurality of threaded holes (121), the positions of the threaded holes (121) corresponding to the positions of holes on the grid plate (14) to be tested; each threaded hole (121) is fixedly connected to a sealing mechanism (13); and the edge of the support plate (12) also has a plurality of support plate through holes (122); During operation, the grid plate (14) to be tested is placed on the flange (81) at the opening of the vacuum chamber (8), so that the grid plate (14) to be tested presses the sealing ring (10); a plurality of sealing mechanisms (13) under the support plate (12) are pressed one by one on the holes on the plurality of grid plates to be tested (14), so that all the holes on the grid plates to be tested (14) are sealed; a connecting bolt (11) is used to connect the threaded hole (121) and the flange through hole (811), so that the support plate through hole (122) and the flange through hole (811) are fastened together, so that the grid plate (14) to be tested seals the vacuum chamber (8); The sealing mechanism (13) comprises a pressure block (1), a sealing film (2), a compression spring (3), a resistance strain sensor (4), a positioning block (5), a hexagon socket polished bolt (6), and a pressure indicator light (7); The positioning block (5) is a cylinder, and a groove (51) is provided at the lower end of the cylinder, and the groove (51) is sleeved on the outer side of the pressing block (1); a plurality of through holes (52) are provided at the upper end of the positioning block (5), and the upper part of the through holes is a countersunk hole, and the position and size of the through holes (52) and the countersunk holes at the upper part thereof match the pressing block threaded hole (101) on the pressing block (1); the resistance strain sensor (4) is pasted in the groove (51), and the resistance strain sensor (4) protrudes downward; the power line is connected to the power supply; the countersunk hole depth of the through hole and the countersunk hole (52) is greater than the reserved spacing h between the pressing block (1) and the resistance strain sensor (4); the signal line and the power line of the resistance strain sensor (4) pass through the small through hole (53) in the groove (51) of the positioning block (5) and are connected to the pressure indicator light (7); The hexagon socket polished bolt (6) passes through the through hole (52) at the upper end of the positioning block (5) and is assembled with the pressing block threaded hole (101) on the upper surface of the pressing block (1), so that the upper end of the hexagon socket polished bolt (6) falls into the countersunk hole in the through hole (52); the compression spring (3) is installed at the lower part of the hexagon socket polished bolt (6); the depth of the hexagon socket polished bolt (6) is adjusted to maintain a suitable distance between the upper surface of the pressing block (1) and the resistance strain sensor (4); the sealing film (2) is pasted on the lower surface of the pressing block (1), and the material of the sealing film (2) is preferably rubber.

2. A helium detection device for porous grid parts according to claim 1, characterized in that: A stud (54) is provided on the upper surface of the positioning block (5) on the sealing mechanism (13), and the positioning block (5) is connected to the threaded hole (121) on the support plate (12) via the stud (54).

3. A helium detection device for porous grid plate parts according to claim 1, characterized in that: The sealing ring (10) is an annular rubber ring.

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