Air inflation axial sealing device used in vacuum environment

[0043] Example 1

[0044] An inflatable axial sealing device used in a vacuum environment, such as figure 2 As shown, it includes an inflatable sealing ring 9, a sealing cylinder 10, an adapter sleeve 11, a pressure gauge 12, a valve 13, an inflation pipe 14 and an air compressor 15, in which an inflatable sealing ring 9, a sealing cylinder 10 and an adapter sleeve The barrel 11 is an axisymmetric structure, which is illustrated by a two-dimensional cross-sectional view in the drawings;

[0045] The inflatable sealing ring 9 is installed in the groove of the adapter sleeve 11, and it is ensured that the sealing ring 9 will not fall off at will in the inflated or non-inflated state. It can be installed by means of glue or slot; inflating the inflatable sealing ring 9 The interface fits well with the inflation interface of the adapter sleeve 11; the inflation sealing ring 9 is in a non-inflated state during the entire installation process, see attached image 3;

[0046] The adapter sleeve 11 is installed at the end (inlet or outlet end) of the vacuum vessel 16 that needs to be sealed, generally by flange connection, see attached Figure 4;

[0047] The sealing cylinder 10 and the piping equipment 8 (the dotted line) are connected as a whole to ensure that the two are in a sealed state. Generally, welding is used to ensure the sealing, see attached Figure 4;

[0048] The sealing cylinder 10 on the pipeline equipment 8 enters the adapter sleeve 11, so that the sealing ring 9 can fully contact the outer surface of the sealing cylinder 10 after it is inflated, see attached image 3;

[0049] The inflation pipe 14 connects the air compressor 15 and the inflation port of the inflation seal ring 9. A pressure gauge 12 and a valve 13 are installed on the inflation pipe 14 to facilitate the detection and control of the inflation process. See attached figure 2.

[0050] The sealing cylinder 10 and the adapter sleeve 11 of the pipeline equipment 8 need to be finished. The outer surface of the sealing cylinder 10 is a straight cylinder with a roughness accuracy of less than 1.6 μm; the inner wall surface of the adapter sleeve 11 is also a straight cylinder. The roughness must also be less than 1.6μm; the outer diameter of the sealing cylinder 10 needs to be determined according to the size of the pipeline device 8, and the outer diameter of the sealing cylinder 10 needs to be slightly greater than or equal to the outer diameter of the pipeline device 8 (when equal to The outer surface of the equipment 8 is directly processed into a straight cylinder with a roughness less than 1.6μm); the sealing cylinder 10 needs to be welded to the pipeline equipment 8 after processing, or directly processed on the outer surface of the pipeline equipment 8 to form a roughness less than 1.6μm Wait straight.

[0051] The inner diameter of the adapter sleeve 11 is larger than the outer diameter of the sealing cylinder 10, and the gap between the two is 3mm~7mm, that is, the inner diameter of the adapter sleeve 11 is the outer diameter of the sealing cylinder 10 plus 6mm~14mm, the formula is D z =D m +6~D m +14, where D z Inner diameter of adapter sleeve 11 (mm), D m It is the outer diameter (mm) of the sealing cylinder 10.

[0052] The adapter sleeve 11 needs to be internally processed with a sealing groove similar to the cross-sectional shape of the sealing ring 9 for installing the sealing ring 9 and leaving an inflatable sealing ring inflation interface, see attached image 3.

[0053] The size of the inflatable sealing ring 9 is selected according to the diameter of the sealing cylinder 10 to ensure that the sealing ring 9 is slightly larger than the outer diameter of the sealing cylinder 10 when it is not inflated, but the sealing ring 9 can be squeezed into the sealing cylinder 10 after inflation. The material of the inflatable sealing ring 9 is silicon rubber or fluorine rubber. The cross-sectional shape of the inflatable sealing ring 9 can be rectangular, circular, trapezoidal or other shapes. After the specification is selected, it can be customized by professional manufacturers.

[0054] The sealing principle of the above pneumatic axial sealing device is as attached image 3 And Figure 5 Shown. After the inflatable axial sealing device is connected, if the inflatable sealing ring 9 is not inflated, as shown image 3 At this time, the device is in a non-sealed state, and the pipeline equipment 8 can be moved and adjusted freely in the axial direction; after the pipeline equipment 8 is installed at the predetermined position, start the air compressor 15 and set a stable pressure value (need to be greater than 101kPa, recommended at 300kPa Left and right), open the valve 13 and inflate the inflatable sealing ring 9 through the inflatable pipe 14. The inner cavity of the inflatable sealing ring 9 expands and the outer surface is respectively squeezed to the inner wall surface of the adapter sleeve 11 and the sealing cylinder 10 on the pipeline device 8. , See attached Figure 5 In this way, the inner wall surface of the adapter sleeve 11-the outer surface of the inflatable sealing ring 9-the outer wall surface of the sealing cylinder 10 form a sealing surface, and the vacuum volume 16 (test section 6 in the wind tunnel equipment) is connected to the pipeline equipment 8 Negative pressure sealing; at the same time, the air compressor 15 automatically detects pressure fluctuations in the sealing ring 9, and automatically completes air supplementation to maintain a constant inflation pressure and a sealed state.

[0055] When the connection between the vacuum volume 16 and the pipeline device 8 does not need to be sealed or the pipeline device 8 needs to be disassembled, the air compressor 15 is turned off, the air in the sealing ring 9 is discharged through the valve 13 and the inflation pipe 14, and the inflation sealing ring 9 automatically returns Bounce into the seal groove of the adapter sleeve 11, the device is in an unsealed state (as attached image 3 ), the pipeline device 8 can move freely in the axial direction, which facilitates the adjustment, removal and replacement of the axial position of the pipeline device 8.

[0056] The working conditions of the inflatable axial sealing device of the present invention are: sealing pressure 10Pa-100000Pa; operating temperature less than 250℃; sealing ring inflation pressure 0.1MPa-0.5MPa; sealing radial gap 3mm-7mm; suitable for various pipes with different diameters The equipment is vacuum sealed.

[0057] Example 2

[0058] The air-filled axial sealing device of the present invention has been used in the Φ1m hypersonic wind tunnel of the China Aerodynamics Research and Development Center for sealing between the nozzle and the test section. The outer diameter of the nozzle is about Φ1.1m, and it is a curved surface, so a straight sealing cylinder with an outer diameter of about Φ1.2m is welded to the outer wall of the nozzle, and the inner diameter of the adapter sleeve is about Φ1.2m.

[0059] As attached Image 6 (The inflatable axial sealing device 17 in the figure is attached figure 2 The components of the inflatable axial sealing device are connected as shown in), the operation steps of using the inflatable axial sealing device Φ1m hypersonic wind tunnel with different Mach number nozzles are as follows:

[0060] 1. Deflate the inflatable sealing ring 9 of the inflatable axial sealing device 17, the inflatable sealing ring 9 is automatically retracted into the groove of the adapter sleeve 11, and the nozzle 3 to be replaced and the test section 6 are in an unsealed state;

[0061] 2. Remove the connecting bolts between the stable section 2 and the replaced nozzle 3, and move the replaced nozzle 3 a certain distance in the direction of the test section 6;

[0062] 3. Disassemble and lift away the stable section 2;

[0063] 4. Move the replaced nozzle 3 back to the fixed equipment 1 for a certain distance and hoist it away by crane;

[0064] 5. Place the nozzle 4 to be replaced on the support mechanism 7 by driving, and the nozzle 4 to be replaced enters the fixed equipment 6 for a certain distance to facilitate the installation of the stable section 2;

[0065] 6. Place the stable section 2 on the support mechanism 7 by driving;

[0066] 7. Connect fixed equipment 1 and stable section 2;

[0067] 7. Retract the nozzle 4 to be replaced and connect it to the stable section 2;

[0068] 8. Open the air compressor 15 and the valve 13 to inflate the sealing ring 9 and carry out the equipment vacuum inspection. The replacement is completed at one time.

[0069] Table 1 shows the improvements obtained after replacing the bellows (inner diameter Φ1.2m) connection mode with an inflatable axial sealing device in a Φ1m hypersonic wind tunnel.

[0070]

[0071] The processing cost of the inner diameter Φ1.2m bellows is about 60,000 yuan, and the processing cycle takes 3 to 5 months. If it is damaged, it needs to be reprocessed; the processing cost of the same diameter inflatable axial seal is about 15,000 yuan, which only takes 1 month The processing can be completed by left and right. Generally, only the inflatable sealing ring may be damaged during use, and the replacement cost is only about 5,000 yuan. Therefore, compared with the bellows, the inflatable axial sealing device has a significant reduction in processing and use costs.

[0072] Generally, the axial adjustment distance of the corrugated pipe with inner diameter of Φ1.2m is ±50mm, and the corrugated pipe itself has certain rigidity. The impact load will be generated during the startup or closing of the wind tunnel. The corrugated pipe itself cannot buffer all the loads. A part of the force acts on the nozzle and the test section through the bellows, and the vibration isolation effect is poor; for the inflatable axial sealing device, as long as the outer diameter of the nozzle is smaller than the inner diameter of the adapter sleeve, the axial movement of the nozzle will not be sealed The device is restricted, and there is no rigid connection between the nozzle and the test section, there will be no force transmission between the nozzle and the test section when subjected to impact load, and the vibration isolation effect is good. Therefore, the inflatable axial sealing device is adopted, which increases the range of the nozzle axial adjustment, facilitates the axial adjustment, removal and replacement of the nozzle, and has a better vibration isolation effect.

[0073] The bellows connection method is adopted. Each time a nozzle with a different Mach number is replaced, 4 people need to work a whole day to complete a replacement; and with an inflatable axial sealing device, only 2 people can work for 2 to 3 hours to complete a replacement. Replacement reduces labor intensity and difficulty of nozzle replacement, and improves nozzle replacement efficiency.

[0074] The beneficial effects of the inflatable axial sealing device of the present invention:

[0075] The invention is used for the inflatable axial sealing device in a vacuum environment. It consists of an inflatable sealing ring, a sealing cylinder, an adapter sleeve, a pressure gauge, a valve, an inflatable pipe, and an air compressor. The processing cost and operating cost of the entire device are both The processing cycle of the bellows equipment below the same caliber is also shorter than the processing time of the bellows. The inflatable axial sealing device basically does not restrict the axial movement between the pipeline equipment and the vacuum volume, and facilitates the axial adjustment, removal and replacement of the pipeline equipment; at the same time, because the pipeline equipment and the vacuum volume are not rigidly connected, the vibration isolation effect is good. Both are better than the bellows connection method. When replacing pipeline equipment with this inflatable axial sealing device, you only need to discharge the gas in the inflatable sealing ring, and the pipeline equipment can realize axial movement, which is simple and quick; for the bellows connection method, the length of the bellows must be compressed first. Then remove the bolts between the bellows and the piping equipment to realize the axial movement of the piping equipment. For large-scale equipment, this process is more difficult and requires a lot of manpower and time, and the bellows is compressed The margin is not large, and the axial adjustment range of the pipeline equipment is also small. At the same time, the bellows is damaged to a certain extent during the compression process, which reduces the service life of the bellows.

[0076] In summary, the inflatable axial sealing device of the present invention solves the shortcomings of the bellows connection mode, reduces investment and operating costs, reduces labor intensity and the difficulty of replacing pipeline equipment, improves the efficiency of pipeline equipment replacement, and obtains good vibration isolation The effect can be applied to axial vacuum sealing between pipeline equipment of different diameters.