JP3444861B2 - Hermetic seal mechanism and seal ring - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an airtight sealing mechanism,
In particular, it relates to an airtight sealing mechanism for the connection between the target vessel and the helium vessel in the neutron scattering facility.

[0002]

2. Description of the Related Art When irradiating a target with a proton beam to generate neutrons in a neutron scattering facility, air existing around the target is activated to increase the number of processing facilities or leakage of the activated air to cause radioactive contamination. In order to prevent the expansion of the target, the surroundings of the target are sealed, and the atmosphere is replaced with helium, which is hard to be activated, for operation.

Therefore, the neutron generating part of the neutron scattering facility is equipped with a helium vessel for enclosing helium. After inserting the tip of the target container loaded with the target into the helium vessel, the target container and the opening of the helium vessel are connected. It seals between them to ensure airtightness and replaces the atmosphere in the helium vessel.

A sealing mechanism as shown in FIGS. 5 and 6 is used for hermetically sealing the target container and the helium vessel. FIG. 5 is a cross-sectional view showing a state in which a conventional target container is inserted into a helium vessel, and FIG. 6 is a partial cross-sectional view of a joint between the target container and the helium vessel.

In the prior art shown in FIGS. 5 and 6, a metal gasket is sandwiched between a flange provided in a target container and a helium vessel for sealing. Since the insertion path of the target container is constricted and the flange of the target container cannot be accessed after inserting the target container into the helium vessel, it is possible to press the target to the vessel with the target dolly without bolting the flange. The sealing property is secured.

However, since the target container and the helium vessel cannot be bolted together, the target container, the helium vessel, etc. are manufactured and mounted with accuracy, the positioning accuracy with respect to the vessel is deteriorated, and the sealing performance is deteriorated due to thermal deformation after operation. Is difficult to compensate for.

In particular, since the maximum diameter of the flange of the target container is as large as about 1 m, when the insertion angle into the vessel is misaligned and the flange hits the wall of the vessel, the gap between the flange and the vessel is significantly large. It becomes very difficult to secure the sealing performance.

When the accuracy of determining the insertion angle is low, in order to prevent the occurrence of a gap and allow the connection surfaces to be in close contact with each other over the entire surface, for example, the target container can be swung so as to conform to the connection surface with the helium vessel. Although a structure method can be considered, it is difficult to realize because the pipes and the like are rigidly connected.

[0009]

Therefore, the problem to be solved by the present invention is to solve the problem between the target container and the helium vessel even if the target container and the helium vessel are not manufactured and mounted with high accuracy and the target container is inserted and positioned with high accuracy. The purpose is to provide an airtight seal that can secure sufficient sealing performance without being bolted and can tolerate thermal deformation.

[0010]

In order to solve the above problems, the hermetic sealing mechanism of the present invention has a taper at the inner edge of the opening of the helium vessel that widens toward the outside of the helium vessel, and the taper of the helium vessel of the target container. A taper that fits the taper of the helium vessel is provided at the part to be joined with, and between the taper of the helium vessel and the taper of the target container, there is a seal ring made of soft elastic metal and conforming to the taper. It is characterized by being interposed and sealed.

In the hermetic sealing mechanism of the present invention, a rectangular target container insertion hole is opened in a hollow, substantially cylindrical helium vessel. Insert the blade of the target container loaded with the target into the target container insertion hole, and insert a rectangular seal ring that matches the target container insertion hole between the taper part provided at the base of the target container and the inner edge of the opening of the helium vessel. Insert and seal.

Since the target container approach path is narrow and the joint between the vessel and the target container cannot be accessed after the target container is inserted, the target truck does not bolt the target vessel to the helium vessel. Seal with the force of pressing.

Since the helium vessel and the target container are joined to each other not at the outer wall around the opening of the vessel but at the inner edge of the opening, the gap formed at the joint portion is small when the axis of the target container or the entrance angle is changed. Therefore, the gap generated by the deviation of the axis of the target container or the approach angle can be compensated by the elasticity of the seal ring, and the deterioration of the sealing property is extremely small. Also, the influence of dimensional change due to thermal deformation is small.

Further, in the sealing mechanism of the present invention, a taper is formed at the portion where the inner edge of the opening of the helium vessel and the inner edge of the opening of the helium vessel of the target container are joined, and the taper of the target container is changed to the taper of the helium vessel. Push in a wedge shape to squeeze and seal the seal ring. In the sealing mechanism of this aspect, the sealing surface is fixed by the self-tightening action of the wedge and the sealing is maintained by the elastic force of the seal ring, and therefore the robustness against insertion error and thermal deformation is high. Further, the self-tightening action of the wedge works, so that it becomes easy to maintain the airtightness without bolting between the target container and the vessel.

If the seal ring has a corrugated cross section in the axial direction and a ridgeline of the corrugation forms a closed curved line, it is possible to secure a large number of seal lines for the seal ring to come into contact with the target container or the vessel and to seal the seal. Since the elasticity of the ring can be increased, the sealing property can be more firmly maintained, which is convenient. Although the sealing mechanism of the present invention is used to seal the rectangular target container insertion hole, the seal ring has a rectangular shape, but if the target container insertion hole is circular, for example, the seal ring is formed into a circular shape. The ring may have other shapes.

On the other hand, the second sealing mechanism of the present invention can be used even when the insertion angle and positioning accuracy of the target container cannot be expected so much that it can be joined to the inner edge of the opening of the helium vessel of the target container. A ring-shaped pressing plate is placed on the top of the helium vessel, and the pressing plate and the target container are connected by a ring-shaped variable shape plate that has elasticity on one side and a target container on the other side. The surface is tapered toward the outside of the helium vessel, and the pressing plate is provided with a taper that fits the taper of the helium vessel.The taper of the helium vessel and the pressing plate are made of an elastic soft metal taper. It may be characterized by sealing with a seal ring having a shape conforming to the above.

In the sealing mechanism of this embodiment, the target container is inserted into the vessel, and the seal ring is inserted between the pressing plate provided in the target container and the inner edge of the opening of the vessel to seal the target container. Since the variable shape plate is present between the pressing plate and the target container, the pressing plate is not rigidly fixed to the target container but can be displaced to some extent. Therefore, even in a situation where the opening of the helium vessel and the target container are not occluded at an appropriate position and angle due to, for example, the axis of the target container or the insertion angle being deviated, the shape-changing plate absorbs the strain. Further, due to the elasticity of the shape-changing plate, the pressing plate conforms to the taper provided in the helium vessel, and the airtightness between the pressing plate and the vessel is secured.

Also, one side of the shape-changing plate is used as a pressing plate,
Since the other side is tightly fixed to the target container by seal welding or the like, the variable shape plate keeps the airtightness between the pressing plate and the target container. Therefore, according to the sealing mechanism of this aspect, the airtightness can be reliably ensured even when the accuracy of the target container such as the approach angle and the positioning is not so high.

Also in the case of this embodiment, when the axial cross section of the seal ring is corrugated, a large number of seal lines are secured so that the seal ring comes into contact with the pressing plate or the vessel, and the elastic force of the seal ring is increased to further firmly maintain the sealing property. can do. Further, it is advantageous that the shape-variable plate has a corrugated cross-section in the axial direction because the flexibility of the shape-variable plate can be increased. The shape of the seal ring can be appropriately selected according to the target container insertion hole such as a rectangle or a circle.

Further, according to the third hermetic sealing mechanism of the present invention, both sides of a highly elastic seal ring are closely fixed to the outer wall of the target container at a position where they are joined to the inner edge of the opening of the helium vessel. It can also be characterized in that pressure is applied to bring the seal ring into close contact with the inner edge of the opening of the helium vessel.

In the sealing mechanism of this embodiment, after the target container is inserted, gas pressure is applied to the seal ring from the target container side, the seal ring is inflated to the helium vessel side, and the seal ring is brought into close contact with the inner edge of the opening of the vessel to ensure hermetic sealing. . Such a seal plate can be manufactured using a superplastic aluminum alloy or the like. The seal mechanism of this aspect is extremely tolerant to errors in the insertion angle of the target container because the seal ring expands according to the size of the gap between the target container and the helium vessel. In addition, since the seal ring is constantly pressed by the gas pressure from the target container side to the vessel, there is little risk of deterioration of the sealability even if the gap between the target container and the vessel expands or contracts due to thermal expansion during operation. .

The target container has a multi-container wall structure, which prevents mercury from flowing out of the inner container for storing the target such as mercury at the innermost side in case of damage to the inner container. A safety hull is installed so that it can be drained to, for example, helium gas of about 0.5 MPa flows. It is advantageous for simplifying the structure of the target container and the like to apply a gas pressure to the seal ring by using this helium gas for safety hull. Of course, a gas pipe for applying gas pressure to the seal ring may be separately provided.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail based on embodiments with reference to the drawings.

[0024]

[Embodiment 1] FIG. 1 is a partial sectional view of an airtight seal mechanism in a first embodiment of the present invention, and FIG. 2 is a perspective view showing a seal ring used in this embodiment. The target container 2 is inserted into the helium vessel 1. Tapers 3 and 4 are formed to be fitted to the inner edge of the opening of the helium vessel 1 and the collar of the target container 2, respectively. The taper 3 is tapered between the taper 3 on the helium vessel 1 side and the taper 4 on the target container 2 side. A seal ring 5 is inserted so that the ridgeline of the mountain in contact with is circularly formed to form a closed curve. A target 6 is loaded in the target container 2.

The target container 2 is carried to a target carriage (not shown) and inserted into the helium vessel 1 through a target container insertion path that penetrates the shield plate. Since the target container insertion path is constricted, after the target container is inserted, the target dolly should not be bolted between the helium vessel 1 and the target container 2, and the target carriage should crush the seal ring 5 using the force pushing the target container 2. To seal the opening. After sealing, fix the target dolly and keep it sealed.

Conventionally, the outer wall 7 of the helium vessel 1 is tightly sealed with the flange provided on the target container 2 by sandwiching the packing, so that the flange can be secured when the insertion angle of the target container is slightly deviated. However, there was a case where a large gap was formed between the flange and the outer wall 7 due to a single contact, resulting in leakage.

Since the sealing mechanism of this embodiment has a structure in which the inner edge of the opening of the helium vessel 1 and the outer periphery of the collar portion of the target container 2 are hermetically sealed, even if the insertion angle or position of the target container deviates. The gap formed between 1 and the target container 2 is small, and the elasticity of the seal ring 5 can be sufficiently supplemented. Therefore, even if there is some error in the approach angle or position of the target container, the sealing property is hardly affected.

Further, since the joints between the helium vessel 1 and the target container 2 are tapered, the target container can be easily inserted. Furthermore, the self-tensioning action of the wedge works and the sealing surface is fixed, so that it is easy to maintain the airtightness.

In this embodiment, since the seal ring 5 has a corrugated cross section in the axial direction, it is possible to secure a large number of seal lines in which the seal ring 5 contacts the helium vessel 1 and the target container 2, and the sealing is highly reliable. Further, since the seal ring 5 is formed in a corrugated cross-section to increase elasticity and flexibility, the allowable amount of displacement of the helium vessel 1 and the target container 2 due to displacement of the target container insertion angle / position and thermal deformation is remarkable. large.

For the seal ring 5, a superplastic metal can be used for the convenience of molding. Titanium-based alloys are usually often used as superplastic metals, but since titanium-based alloys are hard and do not fit well with the contact surface, it may be difficult to ensure airtightness. Therefore, it is desirable to use an aluminum alloy, which is a relatively soft material among the superplastic metals, and for example, a superplastic aluminum alloy such as KS7475 manufactured by Kobe Steel may be used.

When the target container 2 is pulled out from the helium vessel 1, the seal ring 5 is attached to the helium vessel 1.
If it adheres to and remains on the surface, collection work becomes complicated. Therefore,
It is preferable to provide a stopper or the like for fastening the seal ring 5 to the target container 2 so that the seal ring 5 can be collected together with the target container 2 when the target container 2 is pulled out.

[0032]

[Embodiment 2] FIG. 3 is a partial sectional view of an airtight seal mechanism according to a second embodiment of the present invention. One side of the ring-shaped variable shape plate 10 having a corrugated axial direction is seal-welded to the flange of the target container 2, and the other side of the variable-shape plate 10 is seal-welded to a ring-shaped pressing plate 11. A taper 3 is formed on the inner edge of the opening of the helium vessel 1, and a taper 1 fitted to the taper 3 is formed on the outer surface of the pressing plate 11.
2 is formed. A seal ring 5 is inserted between the taper 3 and the taper 12.

The seal mechanism of this embodiment seals the seal ring 5 by crushing it between the taper 3 provided on the helium vessel 1 and the taper 12 provided on the pressing plate 12. Since one side of the shape-changing plate 10 that connects the target container 2 and the pressing plate 11 is seal-welded to the target container 2 and the other side to the pressing plate 11, the shape between the target container 2 and the pressing plate 11 is variable. Airtightness is maintained by the plate 10.

Since the variable shape plate 10 is interposed between the target container 2 and the pressing plate 11, the pressing plate 11 can move to the target container 2 to some extent. Therefore, even if the target container is not inserted into the helium vessel 1 at the correct position and angle, the shape-changing plate 10
Is deformed to absorb the displacement of the position and angle, and the pressing plate 11
The taper 12 and the taper 3 of the helium vessel 1 are properly engaged with each other, and the seal ring 5 is in close contact with both the tapers, so that the sealing property is secured.

In the sealing mechanism of this embodiment, of the forces for pushing the pressing plate 11 toward the tip of the target container, the component force in the direction of bringing the tapered surface into close contact crushes the seal ring 5 and presses the pressing plate 11 and the helium vessel 1. It becomes the power to seal. Therefore, it is necessary that a force is constantly applied to push the pressing plate 11 toward the tip of the target container.

Therefore, in this embodiment, the shape-changing plate 10 is made to have elasticity so that the edge of the target container 2 side is fixed near the tip of the target container and the edge of the pressing plate 11 side is fixed near the root of the target container. Due to the elasticity of the variable plate 10, a force is constantly applied to the pressing plate 11 in the tip direction of the target container. In order to apply the elastic force of the shape changing plate 10, it is preferable that the pressing plate 11 is fixed by hitting the taper 3 during the insertion of the target container, and the shape changing plate 10 is slightly stretched when the target container is completely inserted.

The target container 2 of the shape-changing plate 10
Press the pressing plate 11 with the side edge toward the base of the target container.
The side edge of the side may be fixed near the tip of the target container, and the seal may be secured by using the reaction force against the force that compresses the variable shape plate 10. As in the first embodiment, the seal ring 5 has a corrugated cross section in the axial direction, a large number of seal lines are secured, and the elasticity of the seal ring 5 is increased to improve the sealing property. Also,
It is preferable to provide a stopper or the like for holding the seal ring 5 on the pressing plate 11 so that the seal ring 5 can be collected together with the target container 2 when the target container 2 is pulled out.

[0038]

[Third Embodiment] FIG. 4 is a partial cross-sectional view of an airtight seal mechanism according to a third embodiment of the present invention. At a position facing the inner edge 20 of the helium vessel at the base of the collar of the target container 2, a ring-shaped seal ring 21 having a corrugated axial cross section and having a particularly high elasticity is disposed on both sides of the target container 2 by seal welding. A helium channel 22 through which the helium gas for the safety hull 9 flows is provided around the inner container 8 that stores the target 6 in the target container 2, and is covered with the seal ring 21 of the target container 2. In addition, a helium gas inflow path 23 for introducing helium into a space formed by the seal ring 21 and the outer wall of the target container 2 is provided.

Since mercury, which is a target material, is toxic, is likely to be activated and vaporized and diffused, the helium gas in the safety hull which prevents mercury from flowing out when the inner container storing the target is damaged is about 0. A pressure of 5 MPa is applied. A cooling water flow path 24 is provided around the safety hull 9, and the internal nuclear heat generation of the safety hull 9 is mainly cooled by the water flowing through the cooling water flow path 24. The sealing mechanism of the present embodiment expands the seal ring 21 using the pressure of the helium gas for safety hull, and press-fits the inner ring 20 of the helium vessel to seal it.

After inserting the target container into the helium vessel 1, when the helium gas for safety hull is introduced into the helium flow path 22, the helium gas is formed by the seal ring 21 and the outer wall of the target container 2 through the helium gas inflow path 23. Flows into the sealed space. The inflowing helium gas applies a pressure of about 0.5 MPa to the seal ring 21 to expand the seal ring 21 and bring it into close contact with the inner edge 20 of the helium vessel to seal the target container 2 and the helium vessel 1. The seal ring of this embodiment is, for example, KS of Kobe Steel.
If it is made thin using a superplastic aluminum alloy such as 7475, it can be manufactured so as to be sufficiently expanded at a gas pressure of about 0.5 MPa.

According to the seal mechanism of this embodiment, the seal ring 21 expands and seals until it abuts the inner edge 20, so that
Even if the positioning accuracy of the target container is low, the target container can be reliably sealed. In addition, since the pressure for expanding the seal ring 21 is constantly applied by the helium gas, even if thermal deformation or the like occurs during operation, the seal ring 21 follows the deformation and secures the airtightness, so that leakage of the airtightness may occur. Is extremely small.

Although the inner edge 20 and the base of the target container 2 are tapered in FIG. 4, this is not necessary for the sealing function because of convenience in insertion and withdrawal. Further, the seal ring 21 may be formed in a flat plate shape or a simple arc shape, for example, because the seal ring expands by the pressure of helium gas and closely adheres to the inner edge 20 to secure a seal, but it does not have to have a corrugated cross section in the axial direction. When the seal ring 21 has a corrugated cross section in the axial direction as in the example, a plurality of seal lines can be secured, which is advantageous.

[0043]

As described above, according to the airtight sealing mechanism of the present invention, the bolt between the target container and the helium vessel is not required even if the target container and the helium vessel are not manufactured and attached with high accuracy and the target container is inserted and positioned with high accuracy. It is possible to provide a sufficient sealing performance without stopping and to provide an airtight seal that can also allow thermal deformation.

[Brief description of drawings]

FIG. 1 is a sectional view of an airtight seal mechanism according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a seal ring used in this embodiment.

FIG. 3 is a sectional view of an airtight seal mechanism according to a second embodiment of the present invention.

FIG. 4 is a sectional view of an airtight seal mechanism according to a third embodiment of the present invention.

FIG. 5 is a cross-sectional view of a conventional target, a helium vessel.

FIG. 6 is a partially enlarged sectional view of a conventional airtight seal mechanism.

[Explanation of symbols]

1 helium vessel 2 target container 3 taper 4 taper 5 seal ring 6 targets 7 outer wall 8 inner container 9 Safety Hull 10 variable shape plate 11 Press plate 12 taper 20 Inner edge 21 seal ring 22 Helium flow path 23 Helium gas introduction route 24 heavy water flow path

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryutaro Hino 4 Shirahone, Shirahata, Tokai-mura, Naka-gun, Ibaraki Prefecture 4 Tokai Research Institute, Japan Atomic Energy Research Institute (72) Shinobu Sasaki Toho-mura, Naka-gun, Ibaraki Prefecture 4 in the Shirane area, Japan 4 Atomic Energy Research Institute, Japan Atomic Energy Research Institute (72) Inventor, Masaki Kaminaga, Shirahata, Tokai-mura, Naka-gun, Ibaraki Prefecture 4 in Shirane, Japan Atomic Energy Research Institute Tokai Research Institute (72), inventor, Katsuhiro Haga Ibaraki Prefecture No. 4 in Shirahane, Shikata, Naka-gun, Naka No. 4 inside the Japan Atomic Energy Research Institute, Tokai Research Institute (72) Hidetaka Kinoshita No. 4 in Shirahone, Shirahone, Tokai-mura, Naka-gun, Naka-gun, Ibaraki Prefecture Inside the Tokai Research Institute (56) References JP-A-2003-84100 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16J 15/06 F16J 15/08

Claims (9)

(57) [Claims] 1. An airtight sealing mechanism, comprising a helium vessel, a target container, and a seal ring, which seals a joint portion when the target container is inserted into the opening of the helium vessel, wherein an inner edge of the opening of the helium vessel is provided. The taper has a taper that widens toward the outside of the helium vessel, and a taper that fits the taper of the helium vessel is provided at a portion of the target container that joins with the taper of the helium vessel, and the seal ring has elasticity. An airtight sealing mechanism, which is made of a soft metal and has a shape conforming to the taper, wherein the seal ring is interposed between the taper of the helium vessel and the taper of the target container. 2. An airtight sealing mechanism, comprising a helium vessel, a target container, a pressing plate, and a seal ring, which seals between the helium vessel and the target container when the target container is inserted into the opening of the helium vessel. And the pressing plate has a ring shape slightly larger than the outer circumference of the target container at the position where the pressing plate is joined to the inner edge of the opening of the helium vessel, and one side has elasticity that is closely fixed to the pressing plate and the other side is closely fixed to the target container. The pressing plate and the target container are connected by a ring-shaped shape-changing plate, the inner edge of the opening of the helium vessel has a taper that widens toward the outside of the helium vessel, and the pressing plate is provided in the helium vessel. A taper that fits in the taper is provided, and the seal ring has elasticity. An airtight sealing mechanism, which is made of a soft metal and has a shape conforming to the taper, wherein the seal ring is interposed between the taper of the helium vessel and the taper of the pressing plate for sealing. 3. The airtight seal mechanism according to claim 2, wherein an axial cross section of the variable shape plate is corrugated. 4. An airtight sealing mechanism, comprising a helium vessel, a target container, and a seal ring having high elasticity, and hermetically sealing a joint when the target container is inserted into an opening of the helium vessel. Both ends of the seal ring are closely fixed to a position where the outer wall is joined to the inner edge of the opening of the helium vessel, and the seal ring is applied to the inner edge of the opening of the helium vessel by applying gas pressure from the target container side. Airtight sealing mechanism characterized by close contact. 5. The airtight sealing mechanism according to claim 4, wherein the gas pressure uses helium gas for safety hull which is circulating in the target container. 6. A taper that widens toward the outside of the helium vessel at the inner edge of the opening of the helium vessel, and is fitted to the taper of the helium vessel at a portion of the target container that joins with the taper of the helium vessel. The hermetic seal mechanism according to claim 4 or 5, further comprising a taper. 7. The hermetic seal mechanism according to claim 1, wherein the axial cross section of the seal ring is corrugated. 8. A ring-shaped seal ring interposed between a taper provided on an inner edge of an opening of a helium vessel and a taper provided on a target container or a pressing plate, the shaft being made of a soft metal having elasticity. A seal ring characterized in that the directional cross-section is wavy, and the ridges on the outer peripheral side are in contact with the taper of the helium vessel and the ridges on the inner peripheral side are in contact with the taper of the target container or the pressing plate. 9. A seal ring for sealing a joint portion when a target container is inserted into an opening of a helium vessel, the seal ring being made of a highly flexible soft metal and having a corrugated axial cross section, from the target container side. A seal ring, characterized in that a mountain on the outer peripheral side is brought into close contact with the helium vessel by the applied gas pressure.