High-temperature filtering and flow equalizing device for wind tunnel
By using a high-temperature filtration and flow equalization device in the wind tunnel, the problem of impurities damaging the model and sensors in high-temperature wind tunnel tests was solved, achieving airflow homogenization and filtration effects, and ensuring the accuracy of test data.
Patent Information
- Application Number
- CN202511457190.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-13
- Publication Date
- 2026-01-20
AI Technical Summary
In high-temperature wind tunnel tests, impurities in the airflow can scratch the surface of the test model or clog the measurement sensors, leading to distorted test data or equipment damage.
A high-temperature filtration and flow equalization device for wind tunnels is adopted, including a shell, an outer filter cone tube and an inner filter cone tube. The outer filter cone tube is provided with filter holes, and the inner filter cone tube is provided with air passage holes. Impurities are filtered and the airflow area is increased through a special arrangement. The airflow is made uniform by using baffles and spiral strips.
It effectively filters solid particles in the airflow, reduces the risk of equipment damage, improves airflow uniformity, and ensures the accuracy of test data.
Smart Images
Figure CN121364052A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application relates to the field of wind tunnel test equipment, in particular to a high-temperature filtering and uniform flow device for a wind tunnel. BACKGROUND
[0002] The wind tunnel is a large experimental device for artificially controlling airflow, and is used to study the high-temperature aerodynamic characteristics of an aircraft or an object by simulating the flow state of the aircraft or the object in high-temperature air. The core requirement is the precise controllability of airflow parameters (speed, temperature, pressure, uniformity, etc.).
[0003] In high-temperature wind tunnel tests (such as simulating engine exhaust plumes and atmospheric reentry thermal environments), impurities are usually present in the airflow because the high-temperature airflow may carry solid particles (such as carbon particles and metal oxides) generated by heating devices (such as arc heaters and burners), unburned fuel residues or pipe corrosion debris. These impurities may scratch the surface of the test model, block measurement sensors (such as pressure probes and heat flow meters), and thus cause test data distortion or equipment damage. SUMMARY
[0004] In order to improve the problems existing in the high-temperature wind tunnel test, the application provides a high-temperature filtering and uniform flow device for a wind tunnel.
[0005] The high-temperature filtering and uniform flow device for a wind tunnel provided by the application adopts the following technical scheme: A high-temperature filtering and uniform flow device for a wind tunnel comprises a shell, an air inlet is formed at one end of the shell, an air outlet is formed at the other end of the shell, a mounting pipe is coaxially arranged at the air inlet of the shell, a plurality of outer filter cone pipes are concentrically arranged in the mounting pipe, a plurality of filter holes are formed between the inner and outer sidewalls of the outer filter cone pipes in the circumferential direction, the diameters of the two ends of the outer filter cone pipes are different, the large-diameter end of the outer filter cone pipe located on the inner side is connected to the small-diameter end of the outer filter cone pipe located on the outer side between the two adjacent outer filter cone pipes, the small-diameter end of the outer filter cone pipe located on the inner side is on the same side as the large-diameter end of the outer filter cone pipe located on the outer side, the small-diameter end of the outer filter cone pipe located on the innermost side is provided with a plugging plate, the large-diameter end of the outer filter cone pipe located on the outermost side is provided with an outer protective pipe coaxial with the mounting pipe, the mounting pipe is sleeved on the outer protective pipe, flanges are arranged at the same end of the mounting pipe and the outer protective pipe, and the flanges are arranged at the air inlet of the shell.
[0006] By adopting the technical scheme, the filtering holes on the outer filter cone pipe filter out the solid particles in the high-temperature air, and the filtering holes generate resistance to the high-temperature air, thereby achieving the effect of pressure drop, reducing the possibility that the high-temperature air pressure is too large to directly damage the equipment. However, since the flow area of the high-temperature air on the outer filter cone pipe is increasingly smaller, the surface area through which the high-temperature air flows is increased, the flow capacity of the high-temperature air is improved, and the loss of the high-temperature air pressure is reduced, thereby reducing the initial pressure requirement of the high-temperature air at the air inlet end of the installation pipe. In addition, the taper of the outer filter cone pipe can cause the solid particles in the high-temperature air to gather at the included angle between adjacent two outer filter cone pipes, thereby reducing the possibility that the filtering holes on the taper surface of the outer filter cone pipe are blocked, and facilitating the reduction of the maintenance frequency.
[0007] Optionally, the axis direction of the filtering hole is perpendicular to the taper surface of the outer filter cone pipe.
[0008] By adopting the technical scheme, the axis direction of the filtering hole forms an included angle with the direction of the high-temperature air, thereby reducing the possibility that the solid particles in the high-temperature air directly impact the filtering hole and cause the filtering hole to be blocked.
[0009] Optionally, a plurality of inner filter cone pipes are concentrically arranged in the installation pipe, a plurality of air passing holes are formed between the circumferential inner and outer side walls of the inner filter cone pipe, the diameter of the air passing hole is larger than the diameter of the filtering hole, the diameters of the two ends of the inner filter cone pipe are different, the large-diameter end of the inner filter cone pipe on the inner side is connected with the small-diameter end of the inner filter cone pipe on the outer side between adjacent two inner filter cone pipes, the innermost inner filter cone pipe is coaxially sleeved on the innermost outer filter cone pipe, the outermost outer filter cone pipe is coaxially sleeved on the outermost inner filter cone pipe, the outer filter cone pipe and the inner filter cone pipe are staggered, a plurality of reinforcing plates are arranged between adjacent two inner filter cone pipes and on the side of the inner filter cone pipe away from the outer filter cone pipe, the plurality of reinforcing plates are uniformly distributed along the axis of the installation pipe, there is a spacing between adjacent two outer filter cone pipes and the inner filter cone pipe, and the outermost inner filter cone pipe is fixedly arranged on the inner side wall of the installation pipe.
[0010] By adopting the technical scheme, the high-temperature air flowing through the outer filter cone pipe flows through the air passing holes on the inner filter cone pipe. Since there is a spacing between adjacent two inner filter cone pipes and the outer filter cone pipe, the air pressure between the inner filter cone pipe and the outer filter cone pipe is increased under the hindering effect of the air passing holes on the inner filter cone pipe. Therefore, the high-temperature air between the inner filter cone pipe and the outer filter cone pipe supports the outer filter cone pipe in a gaseous state, thereby reducing the possibility that the outer filter cone pipe is damaged by the high-temperature air flow.
[0011] Optionally, a plurality of L-shaped spoiler plates are arranged on the end of the mounting pipe away from the flange plate, and the plurality of spoiler plates are uniformly distributed along the axis of the mounting pipe.
[0012] By using the above technical scheme, due to the physical phenomenon of hot air rising, the local temperature difference of the high-temperature air flowing through the mounting pipe is generated, and the plurality of circumferentially arranged spoiler plates make the outflowing air flow more uniform, thereby reducing the possibility of uniform deviation of the air flow temperature blowing to the test model, and facilitating to improve the accuracy of the experimental results.
[0013] Optionally, a spacing ring is arranged at the end of the adjacent two outer filter cone pipes away from the flange plate, and the spacing ring abuts against the side walls of the adjacent two inner filter cone pipes.
[0014] By using the above technical scheme, the spacing ring can support and fix the leeward end of the outer filter cone pipe on the inner side, thereby reducing the possibility of deformation of the outer filter cone pipe in the high-temperature and high-pressure air flow for a long time.
[0015] Optionally, a spiral strip is arranged on the side of the inner filter cone pipe facing the inner filter cone pipe and along the axis direction of the mounting pipe, and the spiral strip abuts against the side wall of the outer filter cone pipe.
[0016] By using the above technical scheme, the spiral strip makes the air flow between the inner filter cone pipe and the outer filter cone pipe flow in the spiral direction of the spiral strip, so that the air flow temperature between the inner filter cone pipe and the outer filter cone pipe is more uniform, and the air flow flowing to the test model is more uniform.
[0017] Optionally, the spiral direction of the spiral strip is opposite to the spoiler direction of the spoiler plate.
[0018] By using the above technical scheme, after the air flow out of the air hole impacts the spoiler plate, the possibility of rotation of the air flow is reduced, so that the test model can be impacted by the horizontal air flow.
[0019] Optionally, the cross section of the spacing ring is C-shaped, and the C-shaped open end of the spacing ring faces the flange plate.
[0020] By using the above technical scheme, the solid particles impacting on the side wall of the outer filter cone pipe can be gathered on the C-shaped concave side of the spacing ring, thereby reducing the possibility of the solid particles plugging the filter holes on the outer filter cone pipe.
[0021] In summary, the present application has at least one of the following beneficial technical effects: 1. In the process of high temperature air flowing from the air inlet to the air outlet of the shell, the filter holes on the outer filter cone pipe filter out the solid particles in the high temperature air, and the filter holes generate resistance to the high temperature air, thereby achieving the effect of pressure drop, reducing the possibility of damage to the equipment caused by excessive high temperature air pressure, but because the flow area of the high temperature air on the outer filter cone pipe is increasingly smaller, the surface area through which the high temperature air flows is increased, the flow capacity of the high temperature air is improved, and the loss of high temperature air pressure is reduced, thereby reducing the initial pressure requirement of the high temperature air at the air inlet end of the installation pipe, and the taper of the outer filter cone pipe can cause the solid particles in the high temperature air to accumulate at the included angle between adjacent two outer filter cone pipes, reducing the possibility of the filter holes on the taper surface of the outer filter cone pipe being blocked, and facilitating the reduction of maintenance frequency; 2. The high temperature air flowing through the outer filter cone pipe flows through the air passing holes on the inner filter cone pipe, and because there is a spacing between the adjacent two inner filter cone pipes and the outer filter cone pipe, the air pressure between the inner filter cone pipe and the outer filter cone pipe is increased under the hindering effect of the air passing holes on the inner filter cone pipe, so that the high temperature air between the inner filter cone pipe and the outer filter cone pipe can play a "gaseous" supporting role on the outer filter cone pipe, reducing the possibility of the outer filter cone pipe being blown away by the high temperature air flow; 3. The solid particles impacting on the side wall of the outer filter cone pipe can accumulate on the C-shaped concave side of the spacing ring, reducing the possibility of the solid particles blocking the filter holes on the outer filter cone pipe. BRIEF DESCRIPTION OF DRAWINGS
[0022] Figure 1 is a structural schematic diagram of embodiment 1 of the present application.
[0023] Figure 2 is a sectional view of embodiment 1 of the present application for embodying the positional relationship of the outer protective pipe, the shell and the outer filter cone pipe.
[0024] Figure 3 is a structural schematic diagram of embodiment 1 of the present application for embodying the positional relationship of the installation pipe, the flange plate and the outer filter cone pipe.
[0025] Figure 4 is Figure 2 is an enlarged view of part A in
[0026] Figure 5 is a sectional view of embodiment 2 of the present application for embodying the positional relationship of the outer protective pipe, the installation pipe and the outer filter cone pipe.
[0027] Figure 6 is Figure 5 is an enlarged view of part B in
[0028] Explanation of reference signs: 1, shell; 2, air inlet; 3, air outlet; 4, mounting pipe; 5, outer filter cone pipe; 6, filter hole; 7, blocking plate; 8, outer protective pipe; 9, flange plate; 10, inner filter cone pipe; 11, air passage hole; 12, reinforcing plate; 13, spoiler; 14, spacing ring; 15, spiral strip. DETAILED DESCRIPTION
[0029] The following will be described in detail with reference to the accompanying drawings. Figures 1-6 The application is further described in detail.
[0030] The application discloses a high-temperature filtering and flow uniformizing device for a wind tunnel.
[0031] Embodiment 1 Reference Figure 1 A high-temperature filtering and flow uniformizing device for a wind tunnel comprises a shell 1, one end of the shell 1 is provided with an air inlet 2, and the other end is provided with an air outlet 3.
[0032] Reference Figure 2 And Figure 3 A mounting pipe 4 is coaxially arranged at the air inlet 2 of the shell 1, a plurality of outer filter cone pipes 5 are concentrically arranged in the mounting pipe 4, the outer filter cone pipes 5 are made of high-temperature-resistant materials, a plurality of filter holes 6 are formed between the inner and outer sidewalls of the outer filter cone pipes 5 in the circumferential direction through a laser hole forming device, the diameter of the filter holes 6 is 3 mm, and the axis direction of the filter holes 6 is perpendicular to the conical surface of the outer filter cone pipes 5.
[0033] Reference Figure 2 And Figure 4 The diameters of the two ends of the outer filter cone pipes 5 are different, the large-diameter end of the innermost outer filter cone pipe 5 is welded and connected with the small-diameter end of the outermost outer filter cone pipe 5, the small-diameter end of the innermost outer filter cone pipe 5 is on the same side as the large-diameter end of the outermost outer filter cone pipe 5, and the small-diameter end of the innermost outer filter cone pipe 5 is welded with a blocking plate 7.
[0034] Reference Figure 2 , Figure 3 And Figure 4 The large-diameter end of the outermost outer filter cone pipe 5 is welded with an outer protective pipe 8 coaxial with the mounting pipe 4, the mounting pipe 4 is sleeved on the outer protective pipe 8, the windward ends of the mounting pipe 4 and the outer protective pipe 8 are both welded with a flange plate 9, the flange plate 9 is arranged at the air inlet 2 of the shell 1, and the flange plate 9 on the mounting pipe 4 and the flange plate 9 of the outer protective pipe 8 are both fixed at the air inlet 2 of the shell 1 through bolts.
[0035] In the process of high-temperature air flowing from the air inlet 2 to the air outlet 3 of the shell 1, since the axis direction of the filter hole 6 will form an angle with the direction of the high-temperature air, the solid particles in the high-temperature air will directly impact on the conical surface of the outer filter cone pipe 5 and bounce up, and under the action of the airflow, the solid particles will gather at the angle between the windward surfaces of the adjacent two outer filter cone pipes 5.
[0036] The solid particles in the high-temperature cleaning will be filtered out by the filter hole 6 on the outer filter cone pipe 5, and the high-temperature air will flow through the filter hole 6, in the process, the densely distributed filter holes 6 on the outer filter cone pipe 5 will generate resistance to the high-temperature air flow, thereby realizing the effect of pressure drop, reducing the possibility of direct damage to the equipment caused by excessive high-temperature air pressure.
[0037] Due to the special arrangement of the plurality of outer filter cone pipes 5, the surface area through which the high-temperature air flows is increased, the capacity of the high-temperature air flow is improved, and the loss of the high-temperature air pressure is reduced, thereby reducing the initial pressure requirement of the high-temperature air at the air inlet end of the mounting pipe 4.
[0038] Referring to Figure 2 and Figure 4 , a plurality of inner filter cone pipes 10 are arranged concentrically in the mounting pipe 4, a plurality of air holes 11 are arranged between the circumferential inner and outer sidewalls of the inner filter cone pipe 10, the diameter of the air hole 11 is greater than the diameter of the filter hole 6, and the diameters of the two ends of the inner filter cone pipe 10 are different.
[0039] Referring to Figure 2 and Figure 4 , between the adjacent two inner filter cone pipes 10, the large-diameter end of the inner filter cone pipe 10 on the inner side is welded to the small-diameter end of the inner filter cone pipe 10 on the outer side, the small-diameter end of the inner filter cone pipe 10 on the inner side is on the same side as the large-diameter end of the inner filter cone pipe 10 on the outer side, and the innermost inner filter cone pipe 10 is coaxially sleeved on the innermost outer filter cone pipe 5.
[0040] Referring to Figure 2 and Figure 4 , the outermost outer filter cone pipe 5 is coaxially sleeved on the outermost inner filter cone pipe 10, the outer filter cone pipe 5 and the inner filter cone pipe 10 are arranged alternately, a plurality of reinforcing plates 12 are welded between the adjacent two inner filter cone pipes 10 and on the side of the inner filter cone pipe 10 away from the outer filter cone pipe 5, and the plurality of reinforcing plates 12 are uniformly distributed along the axis of the mounting pipe 4.
[0041] Referring to Figure 2 and Figure 4, the interval between the two adjacent outer filter cone pipe 5 and inner filter cone pipe 10 is 1.5mm, the outermost inner filter cone pipe 10 is welded on the inner wall of the mounting pipe 4, the mounting pipe 4 is welded with multiple L-shaped cross-section spoiler 13 at the end away from the flange 9, the multiple L-shaped cross-section spoiler 13 is evenly distributed along the axis of the mounting pipe 4, the included angle of the L-shaped corner of the spoiler 13 is 135°.
[0042] Because of the interval between the two adjacent inner filter cone pipe 10 and outer filter cone pipe 5, when the high temperature air of the outer filter cone pipe 5 flows to the gap between the inner filter cone pipe 10, the air pressure between the two adjacent inner filter cone pipe 10 and outer filter cone pipe 5 will increase under the hindering effect of the air hole 11.
[0043] Therefore, the high temperature air between the inner filter cone pipe 10 and the outer filter cone pipe 5 will play a "gaseous" supporting role for the outer filter cone pipe 5, reducing the possibility of deformation of the outer filter cone pipe 5 in the high temperature and high pressure air flow for a long time, and the air flow from the air hole 11 makes the temperature of the high temperature air consistent under the action of the multiple circumferentially arranged spoiler 13.
[0044] The implementation principle of example 1 is that: in the process of high temperature air flowing from the air inlet 2 to the air outlet 3 of the shell 1, because the axis direction of the filter hole 6 will form an angle with the direction of the high temperature air, the solid particles in the high temperature air will directly impact on the conical surface of the outer filter cone pipe 5 and bounce up, and under the action of the air flow, the solid particles will gather at the angle of the windward surface of the two adjacent outer filter cone pipe 5.
[0045] The solid particles in the high temperature cleaning will be filtered out by the filter hole 6 on the outer filter cone pipe 5, and the high temperature air will flow through the filter hole 6, in this process, the dense filter hole 6 on the outer filter cone pipe 5 will produce resistance to the high temperature air flow, thereby realizing the effect of pressure drop, reducing the possibility of direct damage to the equipment caused by excessive high temperature air pressure.
[0046] Because of the special arrangement of the multiple outer filter cone pipe 5, the surface area of the high temperature air flow is increased, the capacity of the high temperature air flow is improved, and the loss of the high temperature air pressure is reduced, thereby reducing the initial pressure demand of the high temperature air at the air inlet end of the mounting pipe 4.
[0047] Because of the interval between the two adjacent inner filter cone pipe 10 and outer filter cone pipe 5, when the high temperature air of the outer filter cone pipe 5 flows to the gap between the inner filter cone pipe 10, the air pressure between the two adjacent inner filter cone pipe 10 and outer filter cone pipe 5 will increase under the hindering effect of the air hole 11.
[0048] Therefore, the high-temperature air between the inner filter cone pipe 10 and the outer filter cone pipe 5 plays a role of "gaseous" support for the outer filter cone pipe 5, reducing the possibility of deformation of the outer filter cone pipe 5 in the high-temperature and high-pressure air flow for a long time, and the air flow flowing out of the air hole 11 tends to be uniform in temperature in all places under the action of the plurality of circumferentially arranged spoiler plates 13.
[0049] Embodiment 2 With reference to Figure 2 and Figure 4 The difference between this embodiment and Embodiment 1 is that a spacing ring 14 is welded at one end of the adjacent two outer filter cone pipes 5 and away from the flange plate 9, the spacing ring 14 has a C-shaped cross section, the C-shaped open end of the spacing ring 14 faces the flange plate 9, and the spacing ring 14 simultaneously abuts against the side walls of the adjacent two inner filter cone pipes 10.
[0050] With reference to Figure 2 and Figure 4 Figure 5 Figure 6 Figure 5 Figure 6 The inner filter cone pipe 10 is provided with a spiral strip 15 on the side of the inner filter cone pipe 10 and along the axis direction of the mounting pipe 4, the spiral strip 15 abuts against the side wall of the outer filter cone pipe 5, and the spiral direction of the spiral strip 15 is opposite to the spoiler direction of the spoiler plate 13.
[0051] The implementation principle of Embodiment 2 is that the solid particles impacting on the side wall of the outer filter cone pipe 5 will finally gather on the C-shaped concave side of the spacing ring 14, reducing the possibility of plugging of the filter holes 6 on the outer filter cone pipe 5 by the solid particles, and reducing the maintenance frequency of the outer filter cone pipe 5.
[0052] The spiral strip 15 makes the air flow between the inner filter cone pipe 10 and the outer filter cone pipe 5 flow in the spiral direction of the spiral strip 15, and in the process of air flow, the temperature of the air flow between the inner filter cone pipe 10 and the outer filter cone pipe 5 gradually becomes uniform, so that the temperature of the air flow flowing to the test model is more uniform.
[0053] The above are preferred embodiments of the present application, which do not limit the protection scope of the present application, so: any equivalent changes made on the basis of the structure, shape, principle of the present application should be covered within the protection scope of the present application.
Claims
1. A high-temperature filtration and flow equalization device for wind tunnels, characterized in that: The device includes a housing (1), with an air inlet (2) at one end and an air outlet (3) at the other end. An installation pipe (4) is coaxially arranged at the air inlet (2) of the housing (1). Multiple external filter cones (5) are concentrically arranged within the installation pipe (4). Several filter holes (6) are formed between the inner and outer circumferential walls of each external filter cone (5). The two ends of each external filter cone (5) have different diameters. Between two adjacent external filter cones (5), the larger diameter end of the inner external filter cone (5) and the smaller diameter end of the outer external filter cone (5) are connected. The outer filter cone tube (5) is connected at the inner end, and the small diameter end of the outer filter cone tube (5) is on the same side as the large diameter end of the outer filter cone tube (5) located on the outer side. The small diameter end of the innermost outer filter cone tube (5) is provided with a sealing plate (7), and the large diameter end of the outermost outer filter cone tube (5) is provided with an outer protective tube (8) coaxial with the mounting tube (4). The mounting tube (4) is sleeved on the outer protective tube (8). The same end of the mounting tube (4) and the outer protective tube (8) is provided with a flange (9). The flange (9) is arranged at the air inlet (2) of the housing (1).
2. The high-temperature filtration and flow equalization device for wind tunnels according to claim 1, characterized in that: The axial direction of the filter hole (6) is perpendicular to the conical surface of the external filter cone tube (5).
3. The high-temperature filtration and flow equalization device for wind tunnels according to claim 1, characterized in that: Multiple inner filter cones (10) are concentrically arranged inside the mounting tube (4). Several air passages (11) are formed between the inner and outer circumferential walls of each inner filter cone (10). The diameter of each air passage (11) is larger than the diameter of the filter hole (6). The two ends of each inner filter cone (10) have different diameters. Between two adjacent inner filter cones (10), the larger diameter end of the inner inner filter cone (10) is connected to the smaller diameter end of the outer inner filter cone (10). The innermost inner filter cone (10) is coaxially sleeved on the innermost outer filter cone (5). The outermost... The outer filter cone tube (5) is coaxially sleeved on the outermost inner filter cone tube (10). The outer filter cone tube (5) and the inner filter cone tube (10) are arranged alternately. Multiple reinforcing plates (12) are provided between two adjacent inner filter cone tubes (10) and on the side of the inner filter cone tube (10) facing away from the outer filter cone tube (5). The multiple reinforcing plates (12) are evenly distributed circumferentially along the axis of the mounting tube (4). There is a gap between two adjacent outer filter cone tubes (5) and the inner filter cone tube (10). The outermost inner filter cone tube (10) is fixedly installed on the inner side wall of the mounting tube (4).
4. A high-temperature filtration and flow equalization device for wind tunnels according to claim 3, characterized in that: The mounting pipe (4) is provided with a plurality of L-shaped baffles (13) at one end facing away from the flange (9), and the plurality of baffles (13) are evenly distributed circumferentially along the axis of the mounting pipe (4).
5. A high-temperature filtration and flow equalization device for wind tunnels according to claim 4, characterized in that: A spacing ring (14) is provided at one end of each of the two adjacent outer filter cones (5) facing away from the flange (9), and the spacing ring (14) simultaneously abuts against the side wall of the two adjacent inner filter cones (10).
6. A high-temperature filtration and flow equalization device for wind tunnels according to claim 5, characterized in that: The inner filter cone tube (10) has a spiral strip (15) wound around the side facing the inner filter cone tube (10) and along the axial direction of the mounting tube (4), and the spiral strip (15) abuts against the side wall of the outer filter cone tube (5).
7. A high-temperature filtration and flow equalization device for wind tunnels according to claim 6, characterized in that: The spiral direction of the spiral strip (15) is opposite to the turbulence direction of the spoiler (13).
8. A high-temperature filtration and flow equalization device for wind tunnels according to claim 5, characterized in that: The cross-section of the spacing ring (14) is C-shaped, and the C-shaped open end of the spacing ring (14) faces the flange (9).