Volcanic ash intrusion prevention agency

Abstract

Even if a volcanic ash filter is not installed at the outside air intake, the system should suppress the intrusion of volcanic ash from the outside air intake during ashfall, and allow a large amount of outside air to be taken in through the outside air intake during normal times when there is no volcanic ash falling. [Solution] The volcanic ash intrusion prevention mechanism is designed to be movable between an deployed position, which covers the outside air intake from above when deployed, and a stored position, which allows a large amount of outside air to be taken in through the outside air intake when retracted.

Description

Technical Field

[0001] The present disclosure relates to a mechanism for preventing volcanic ash intrusion.

Background Art

[0002] The intake filter system described in Patent Document 1 is an intake filter system that covers an intake port for taking in outside air provided on the outer wall of a building. The intake filter system includes an exterior body that is attached to the outer wall, has an internal space where the intake port is disposed and has an opening that is open downward at the lowermost part, and a filter unit that is disposed between the intake port and the opening in the internal space and is detachably attached to the exterior body and can remove volcanic ash.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, in areas where volcanic ash may fall, volcanic ash may intrude into buildings and tunnels through outside air intake ports for taking in outside air provided in buildings and tunnels during ash fall. For this reason, it may be possible to prevent volcanic ash from intruding into buildings and tunnels by providing a volcanic ash filter or the like at the outside air intake port.

[0005] The problem of the present disclosure is to suppress the intrusion of volcanic ash from the outside air intake port during ash fall even when a volcanic ash filter is not provided at the outside air intake port, and to take in a large amount of outside air from the outside air intake port during normal times when no volcanic ash is falling.

Means for Solving the Problems

[0006] The volcanic ash intrusion prevention mechanism according to the first embodiment is characterized by comprising an ash intrusion suppression member that can move between an deployed position, which covers an outside air intake that takes in outside air from above when deployed, and a stored position, which takes in a large amount of outside air through the outside air intake when stored.

[0007] According to the above embodiment, the ash intrusion suppression member is movable between an deployed position and a retracted position. When ash falls, the ash intrusion suppression member is moved to the deployed position, and during normal times when volcanic ash is not falling, the ash intrusion suppression member is moved to the retracted position. This makes it possible to suppress the intrusion of volcanic ash from the outside air intake during ashfall, even if a volcanic ash filter is not provided at the outside air intake, and to take in a large amount of outside air from the outside air intake during normal times when volcanic ash is not falling.

[0008] The volcanic ash intrusion prevention mechanism according to the second embodiment is characterized in that, in the volcanic ash intrusion prevention mechanism described in the first embodiment, the ash intrusion suppression member has a sheet-like sheet member, and when the ash intrusion suppression member is moved to the deployed position, the sheet member is configured to include an umbrella portion that covers the outside air intake in an umbrella shape above the outside air intake, and a hanging curtain portion that hangs down from the outer edge of the umbrella portion to the outside air intake and has an inlet for introducing outside air at its lower end.

[0009] According to the above embodiment, by extending the curtain portion downward relative to the outside air intake, the intrusion of volcanic ash from the outside air intake can be effectively suppressed compared to the case where the lower end of the curtain portion is positioned above the outside air intake.

[0010] The volcanic ash intrusion prevention mechanism according to the third embodiment is characterized in that, in the volcanic ash intrusion prevention mechanism described in the second embodiment, the opening area of ​​the inlet is larger than the opening area of ​​the outside air intake.

[0011] According to the above embodiment, compared to the case where the opening area of ​​the inlet is smaller than the opening area of ​​the outside air intake, sufficient outside air can be taken in from the outside air intake even when the ash intrusion suppression member is moved to the deployed position. [Effects of the Invention]

[0012] According to this disclosure, even if a volcanic ash filter is not installed at the outside air intake, the intrusion of volcanic ash from the outside air intake can be suppressed during ashfall, and a large amount of outside air can be taken in from the outside air intake during normal times when volcanic ash is not falling. [Brief explanation of the drawing]

[0013] [Figure 1] This is a perspective view showing a volcanic ash intrusion prevention mechanism according to the first embodiment of the present disclosure, in which the ash intrusion suppression member has moved to its storage position. [Figure 2] This is a perspective view showing a volcanic ash intrusion prevention mechanism according to the first embodiment of the present disclosure, in which the ash intrusion suppression member has moved to the deployed position. [Figure 3] (A)(B) This is an explanatory diagram illustrating a volcanic ash intrusion prevention mechanism according to the first embodiment of the present disclosure, in which an ash intrusion suppression member moves between a storage position and an unfolded position. [Figure 4] (A)(B) This is an explanatory diagram illustrating a volcanic ash intrusion prevention mechanism according to the first embodiment of the present disclosure, in which an ash intrusion suppression member moves between a storage position and an unfolded position. [Figure 5] This is a schematic diagram showing a volcanic ash intrusion prevention mechanism according to the first embodiment of the present disclosure, in which the ash intrusion suppression member has moved to the deployed position. [Figure 6] This is a perspective view showing a volcanic ash intrusion prevention mechanism according to a second embodiment of the present disclosure, in which the ash intrusion suppression member has moved to its storage position. [Figure 7] This is a perspective view showing a volcanic ash intrusion prevention mechanism according to a second embodiment of the present disclosure, in which the ash intrusion suppression member has moved to the deployed position. [Figure 8] (A)(B) This is an explanatory diagram illustrating a volcanic ash intrusion prevention mechanism according to a second embodiment of the present disclosure, in which an ash intrusion suppression member moves between a storage position and an unfolded position. [Figure 9](A)(B)This is an explanatory diagram showing the process in which the volcanic ash intrusion prevention mechanism according to the second embodiment of the present disclosure moves between the storage position and the deployment position.

Mode for Carrying Out the Invention

[0014] <First Embodiment> An example of the volcanic ash intrusion prevention mechanism according to the first embodiment of the present disclosure will be described with reference to FIGS. 1 to 5. The arrow H shown in each figure indicates the vertical direction, which is the up-down direction of the volcanic ash intrusion prevention mechanism, and the arrow W shown in each figure indicates the width direction of the volcanic ash intrusion prevention mechanism, which is orthogonal to the arrow H and is in the horizontal direction. The arrow D shown in each figure indicates the depth direction of the volcanic ash intrusion prevention mechanism, which is orthogonal to the arrow H and the arrow W and is in the horizontal direction.

[0015] (Volcanic Ash Intrusion Prevention Mechanism 10) As shown in FIGS. 1 and 2, the volcanic ash intrusion prevention mechanism 10 is attached to a cylindrical outside air intake portion 100 extending in the up-down direction using a mounting member not shown. The volcanic ash intrusion prevention mechanism 10 includes an ash intrusion suppression member 12 that is movable between a storage position (see FIG. 1) and a deployment position (see FIG. 2), and a drive unit 42 that drives and moves the ash intrusion suppression member 12.

[0016] In a state where the ash intrusion suppression member 12 has moved to the storage position, as shown in FIG. 1, a large amount of outside air is taken in from a circular outside air intake port 100a (so-called "intake port") formed at the upper end of the outside air intake portion 100. On the other hand, in a state where the ash intrusion suppression member 12 has moved to the deployment position, the ash intrusion suppression member 12 covers the outside air intake port 100a from above as shown in FIG. 2.

[0017] 〔Ash Intrusion Suppression Member 12〕 As shown in FIGS. 1 and 2, the ash intrusion suppression member 12 includes a frame member 14 and a sheet-like sheet member 34 supported by the frame member 14.

[0018] -Frame Member 14- As shown in FIGS. 1 and 2, the frame member 14 includes a middle rod 16 extending in the vertical direction and a plurality of support ribs 18 arranged in the circumferential direction of the middle rod 16 as viewed from the vertical direction. Further, the frame member 14 includes a plurality of first receiving ribs 20 arranged in the circumferential direction of the middle rod 16 as viewed from the vertical direction, a second receiving rib 22, and an annular ring rib 24 attached to the upper end of the outside air intake portion 100. In the present embodiment, the plurality of support ribs 18, the plurality of first receiving ribs 20, and the plurality of second receiving ribs 22 are respectively arranged at the same intervals in the circumferential direction of the middle rod 16, and six of each are provided.

[0019] The middle rod 16 is, for example, made of metal, glass fiber, or resin, has a circular cross-section, is arranged at the center of the outside air intake 100a as viewed from the vertical direction, and extends in the vertical direction. And the middle rod 16 is supported by a support member (not shown) so as to be movable in the vertical direction. Specifically, the middle rod 16 is movable in the vertical direction within a predetermined range by a stopper not shown.

[0020] The support rib 18 (see FIG. 5) is, for example, made of metal, glass fiber, or resin, has a circular cross-section, and as viewed from the vertical direction, the plurality of support ribs 18 are arranged in the circumferential direction of the middle rod 16 and extend in the radial direction of the middle rod 16. And one end of each support rib 18 is rotatably attached to the middle rod 16 via a connecting member 30. Further, this connecting member 30 is attached to the middle rod 16 so as to be movable in the vertical direction.

[0021] The ring rib 24 is, for example, made of metal, glass fiber, or resin, has a circular cross-section, is annular with the middle rod 16 as the center as viewed from the vertical direction, and is attached to the upper end edge of the outside air intake portion 100 using a mounting member not shown. A plurality of connecting members 32 are attached to the ring rib 24 at intervals, and the other end portion of the support rib 18 is attached to the connecting member 32. Specifically, the other end portion of the support rib 18 is attached to the connecting member 32 so as to be movable in the axial direction of the support rib 18 and rotatable with respect to the ring rib 24.

[0022] The first support ribs 20 (see Figure 5) are made of, for example, metal, glass fiber, or resin, and have a circular cross-section. When viewed from above, multiple first support ribs 20 are arranged circumferentially around the central rod 16 and extend radially around the central rod 16. One end of each first support rib 20 is rotatably attached to the connecting member 30. In other words, each first support rib 20 is rotatable relative to the central rod 16. When the ash intrusion suppression member 12 is moved to the storage position, the first support ribs 20 extend vertically (see Figure 3(A)). On the other hand, when the ash intrusion suppression member 12 is moved to the deployed position, the first support ribs 20 extend diagonally upward from the connecting member 30 in the horizontal direction (see Figure 4(B)).

[0023] The second support bones 22 (see Figure 5) are made of, for example, metal, glass fiber, or resin, and have a circular cross-section. When viewed from above, multiple second support bones 22 are arranged circumferentially around the central rod 16 and extend radially from the central rod 16. One end of each second support bone 22 is rotatably attached to the connecting member 30. In other words, each second support bone 22 is rotatable relative to the central rod 16. When the ash intrusion suppression member 12 is moved to the storage position, the second support bones 22 extend vertically (see Figure 3(A)). On the other hand, when the ash intrusion suppression member 12 is moved to the deployed position, the second support bones 22 extend horizontally from the connecting member 30 (see Figure 4(B)).

[0024] -Sheet material 34- The sheet member 34 is formed using a resin sheet material and, as shown in Figures 2 and 4(B), comprises an umbrella portion 36 and a curtain portion 38. When the ash intrusion suppression member 12 is moved to the deployed position, the umbrella portion 36 covers the outside air intake 100a from above in an umbrella shape. The curtain portion 38 hangs down from the outer peripheral edge 36a of the umbrella portion 36 toward the outside air intake 100a.

[0025] Specifically, the umbrella portion 36 is supported by the frame member 14 by being attached to the tip of the central shaft 16, the other ends of the multiple first ribs 20, and the other ends of the multiple second ribs 22. When the ash intrusion suppression member 12 is moved to the deployed position, the umbrella portion 36 becomes spherical with the tip of the central shaft 16 at its center, as shown in Figure 2, and the outer edge 36a of the umbrella portion 36 surrounds the outside air intake 100a when viewed from above.

[0026] Furthermore, with the ash intrusion suppression member 12 in the deployed position, the curtain portion 38 hangs down from the outer peripheral edge 36a of the umbrella portion 36 to the outside air intake 100a. The curtain portion 38 is cylindrical in shape and extends vertically, covering the outside air intake 100 from the radially outer side.

[0027] In this state, an outside air intake passage 110 is formed between the curtain portion 38 and the outer surface of the outside air intake portion 100, as shown in Figure 5, through which the introduced outside air flows. The cross-sectional area of ​​this outside air intake passage 110 is made larger than the opening area of ​​the outside air intake port 100a. In other words, the opening area of ​​the intake port 110a formed at the lower end of the curtain portion 38 for introducing outside air is made larger than the opening area of ​​the outside air intake port 100a.

[0028] [Drive unit 42] The drive unit 42 is composed of a transmission unit that combines known mechanical components such as gears, and a motor that operates the transmission unit. The drive unit 42 shown in Figure 2 is configured to move the central rod 16 from the lowest position to the highest position, and the central rod 16 from the highest position to the lowest position.

[0029] (action) Next, we will describe the process by which the ash intrusion suppression member 12 moves between the storage position and the deployed position.

[0030] As shown in Figures 1 and 3(A), with the ash intrusion suppression member 12 moved to its storage position, the central rod 16 is positioned at the lowest position within its movable range. The connecting member 30 is positioned below the outside air intake 100a.

[0031] Furthermore, the first support bone 20 and the second support bone 22, one end of which is attached to the connecting member 30, are arranged to extend in the vertical direction. Also, the support bone 18, one end of which is attached to the connecting member 30, is inclined such that one end is downward relative to the other end.

[0032] In this state, the sheet member 34 is folded. The folded sheet member 34 is positioned inside the outside air intake 100a when viewed from above, and the sheet member 34 and the inner surface of the outside air intake 100 are separated in the radial direction of the central rod 16. In this way, with the ash intrusion suppression member 12 moved to the storage position, the outside air intake 100a, which opens upward, is designed to directly take in outside air from above (in the opening direction).

[0033] Here, for example, based on eruption warning information, an operator operates the drive unit 42 to move the ash intrusion suppression member 12 from the storage position to the deployed position. Specifically, when the drive unit 42 moves the central rod 16, which is located at the lowest position, upward, the tip of the central rod 16 pushes the sheet member 34 upward, as shown in Figures 3(B) and 4(A). As the sheet member 34 is pushed upward, the other end of the first support bone 20 and the other end of the second support bone 22 are lifted. Also, as the other end of the first support bone 20 and the other end of the second support bone 22 are lifted, they attempt to separate from the central rod 16, and the first support bone 20 and the second support bone 22 rotate around the connecting member 30.

[0034] As the first support bone 20 and the second support bone 22 rotate around the connecting member 30, the connecting member 30 moves upward. As the connecting member 30 moves upward, one end of the support bone 18 moves upward, and the support bone 18 tilts so that one end of the support bone 18 is above the other end.

[0035] Furthermore, when the drive unit 42 moves the central rod 16 upward and positions it at the uppermost position, as shown in Figure 4(B), the second support bone 22 extends horizontally, and the first support bone 20 tilts horizontally such that its other end is above one end.

[0036] In this state, the umbrella portion 36 of the sheet member 34 covers the outside air intake 100a from above in an umbrella shape (like an umbrella). The curtain portion 38 hangs down from the outer peripheral edge 36a of the umbrella portion 36 to the outside air intake 100a, and an outside air intake passage 110 is formed between the curtain portion 38 and the outer peripheral surface of the outside air intake portion 100, through which the outside air introduced from the inlet 110a flows.

[0037] As a result, with the ash intrusion suppression member 12 in its deployed position, the umbrella portion 36 of the sheet member 34 prevents large-grained (coarse) volcanic ash from entering the outside air intake 100a. Furthermore, medium-grained volcanic ash cannot ascend the outside air intake passage 110 formed between the curtain portion 38 and the outside air intake portion 100, thus preventing it from entering the outside air intake 100a.

[0038] Furthermore, for volcanic ash with a small particle size (fine), the suction speed in the outside air intake passage 110 between the curtain section 38 and the outside air intake section 100 is reduced, thereby suppressing its entry into the outside air intake port 100a. Specifically, the cross-sectional area of ​​the outside air intake passage 110 between the curtain section 38 and the outside air intake section 100 is made larger than the opening area of ​​the outside air intake port 100a. This reduces the suction speed of the outside air intake passage 110.

[0039] Furthermore, when moving the ash intrusion suppression member 12 from the deployed position to the storage position, the reverse of the process described above is performed.

[0040] (summary) As explained above, in the volcanic ash intrusion prevention mechanism 10, the ash intrusion suppression member 12 is movable between an deployed position and a retracted position. This allows volcanic ash to enter through the outside air intake 100a even if a volcanic ash filter is not provided at the outside air intake. When ash falls, the ash intrusion suppression member 12 can be moved to the deployed position to suppress the intrusion of volcanic ash from the outside air intake 100a. Furthermore, even if a volcanic ash filter is not provided at the outside air intake, when volcanic ash is not falling, the ash intrusion suppression member 12 can be moved to the retracted position to allow a large amount of outside air to be taken in through the outside air intake 100a.

[0041] Furthermore, in the volcanic ash intrusion prevention mechanism 10, the sheet member 34 is composed of an umbrella portion 36 and a curtain portion 38 that hangs down from the outer peripheral edge 36a of the umbrella portion 36 toward the outside air intake 100a and has an inlet 110a for introducing outside air at its lower end. By extending the curtain portion 38 toward the outside air intake 100a in this way, it is possible to effectively suppress the intrusion of volcanic ash from the outside air intake 100a.

[0042] Furthermore, in the volcanic ash intrusion prevention mechanism 10, the opening area of ​​the inlet 110a is made larger than the opening area of ​​the outside air intake 100a. As a result, compared to the case where the opening area of ​​the inlet is smaller than the opening area of ​​the outside air intake, sufficient outside air can be taken in from the outside air intake 100a even when the ash intrusion suppression member 12 is moved to the deployed position.

[0043] <Second Embodiment> An example of a volcanic ash intrusion prevention mechanism according to the second embodiment of this disclosure will be described with reference to Figures 6 to 9. The second embodiment will primarily describe the differences from the first embodiment.

[0044] (Volcanic ash intrusion prevention mechanism 60) The volcanic ash intrusion prevention mechanism 60 is attached to the rooftop 202 of the structure 200, as shown in Figures 6 and 7. In addition, an outside air intake 204a is formed in the outer wall 204 of the structure 200 in the portion close to the rooftop 202.

[0045] The volcanic ash intrusion prevention mechanism 60 includes an ash intrusion suppression member 62 that is movable between a stored position (see Figure 6) and an deployed position (see Figure 7), and a drive unit 92 that drives and moves the ash intrusion suppression member 62.

[0046] When the ash intrusion suppression member 62 is moved to the storage position, as shown in Figure 6, a large amount of outside air is taken in through the outside air intake 204a (so-called "air intake") formed in the outer wall 204 of the structure 200. On the other hand, when the ash intrusion suppression member 62 is moved to the deployed position, as shown in Figure 7, the ash intrusion suppression member 62 covers the outside air intake 204a from the horizontal direction.

[0047] [Ash intrusion suppression member 62] As shown in Figures 6 and 7, the ash intrusion suppression member 62 comprises a frame member 64 and a sheet-like sheet member 84 supported by the frame member 64.

[0048] -Frame member 64- The frame member 64 comprises a plurality of arch bones 66, support bones 68, and support parts 70.

[0049] The arch ribs 66 are arc-shaped, and both ends of multiple arch ribs 66 are attached to the support parts 70. The support ribs 68 are arc-shaped and are attached to the ends of the sheet member 84.

[0050] The pair of support parts 70 are attached near the corner 206 formed by the rooftop 202 and the exterior wall 204, and are spaced apart in the direction in which the corner 206 extends (in this embodiment, the width direction). The support parts 70 support multiple arch ribs 66 such that the arch ribs 66 rotate around the axis of separation direction of the pair of support parts 70.

[0051] -Sheet material 84- The sheet member 84 is formed using a resin sheet material and, as shown in Figures 7 and 9(B), comprises an umbrella portion 86 and a curtain portion 88. When the ash intrusion suppression member 62 is moved to the deployed position, the umbrella portion 86 protrudes outward from the rooftop 202 and covers the outside air intake 204a from above.

[0052] The umbrella section 86 is attached to and supported by multiple arch ribs 66. Specifically, with the ash intrusion suppression member 62 moved to the deployed position, the umbrella section 86 is attached to the arch ribs 66 such that the multiple arch ribs 66 are spaced similarly apart in the rotational direction of the arch ribs 66.

[0053] Furthermore, with the ash intrusion suppression member 62 in the deployed position, the curtain portion 88 hangs down from the protruding edge 86a of the umbrella portion 86 that protrudes from the outside, toward the outside air intake 204a. The curtain portion 88 covers the outside air intake 204a from the side (opening direction). The protruding edge 86a is an example of an outer peripheral edge.

[0054] In this state, the cross-sectional area of ​​the outside air intake passage 210 formed between the curtain section 88 and the outer wall 204 is made larger than the opening area of ​​the outside air intake 204a. In other words, the opening area of ​​the inlet 210a for introducing outside air, formed at the lower end of the curtain section 88, is made larger than the opening area of ​​the outside air intake 204a.

[0055] [Drive unit 92] The drive unit 92 is composed of a transmission unit that combines known mechanical components such as gears, and a motor that operates the transmission unit. The drive unit 92 rotates the multiple arch bones 66 shown in Figure 7 and moves the support bones 68 to expand or fold the curtain section 88.

[0056] (action) Next, we will describe the process by which the ash intrusion suppression member 62 moves between the storage position and the deployed position.

[0057] As shown in Figures 6 and 8(A), with the ash intrusion suppression member 62 moved to its storage position, the multiple arch ribs 66 and support ribs 68 are stacked on top of the rooftop 202, and the sheet member 84 is folded on top of the rooftop 202.

[0058] With the ash intrusion suppression member 62 moved to its storage position, the outside air intake 204a, which opens to the side, is configured to directly take in outside air from the side (opening direction).

[0059] Here, for example, based on eruption warning information, an operator operates the drive unit 92 to move the ash intrusion suppression member 62 from the stored position to the deployed position. Specifically, when the drive unit 92 rotates the arch frame 66 and support frame 68, as shown in Figures 8(B) and 9(A), the arch frame 66 and support frame protrude outward from the rooftop 202, and the umbrella portion 86 covers the outside air intake 204a from above. Furthermore, by moving the support frame 68 downward using a mechanism not shown, as shown in Figures 9(A) and (B), the folded curtain portion 88 expands and hangs down from the protruding edge 86a of the umbrella portion 86 to the outside air intake 204a. Then, an outside air intake passage 210 is formed between the curtain portion 88 and the outer wall 204, through which the outside air introduced from the inlet 210a flows.

[0060] In this way, the ash intrusion suppression member 62, which is stored in its storage position, moves to its deployed position. In this state, the umbrella portion 86 of the sheet member 84 prevents large-grained (coarse) volcanic ash from entering the outside air intake 204a. Furthermore, medium-grained volcanic ash cannot ascend the outside air intake passage 210 formed between the curtain portion 88 and the outer wall 204, thus preventing it from entering the outside air intake 204a.

[0061] Furthermore, for volcanic ash with a small particle size (fine), the suction velocity in the outside air intake passage 210 between the curtain section 88 and the outer wall 204 is reduced, thereby suppressing its intrusion into the outside air intake port 204a. Specifically, the cross-sectional area of ​​the outside air intake passage 210 between the curtain section 88 and the outer wall 204 is made larger than the opening area of ​​the outside air intake port 204a. This reduces the suction velocity of the outside air intake passage 210.

[0062] Furthermore, when moving the ash intrusion suppression member 62 from the deployed position to the storage position, the reverse of the process described above is performed.

[0063] (summary) As explained above, in the volcanic ash intrusion prevention mechanism 60, the ash intrusion suppression member 62 is movable between an deployed position and a retracted position. This allows the ash intrusion suppression member 62 to be moved to the deployed position during ashfall, even if a volcanic ash filter is not provided at the outside air intake, thereby suppressing the intrusion of volcanic ash from the outside air intake 204a. Furthermore, even if a volcanic ash filter is not provided at the outside air intake, the ash intrusion suppression member 62 can be moved to the retracted position during normal times when volcanic ash is not falling, allowing a large amount of outside air to be directly taken in through the outside air intake 204a.

[0064] Furthermore, in the volcanic ash intrusion prevention mechanism 60, the sheet member 84 is composed of an umbrella portion 86 and a curtain portion 88 that hangs down from the protruding edge 86a of the umbrella portion 86 toward the outside air intake 204a and has an inlet 210a for introducing outside air at its lower end. By extending the curtain portion 88 toward the outside air intake 204a in this way, the intrusion of volcanic ash from the outside air intake 204a can be effectively suppressed.

[0065] Furthermore, in the volcanic ash intrusion prevention mechanism 60, the opening area of ​​the inlet 210a is made larger than the opening area of ​​the outside air intake 204a. As a result, compared to the case where the opening area of ​​the inlet is smaller than the opening area of ​​the outside air intake, sufficient outside air can be taken in from the outside air intake 204a even when the ash intrusion suppression member 62 is moved to the deployed position.

[0066] Although this disclosure has described specific embodiments in detail, it will be apparent to those skilled in the art that this disclosure is not limited to these embodiments, and that various other embodiments are possible within the scope of this disclosure. For example, in the above embodiment, the outside air intake 100a is circular, but it may be rectangular or the like.

[0067] Furthermore, although not specifically described in the above embodiment, the volcanic ash intrusion prevention mechanisms 10 and 60 may also include control units that operate the drive units 42 and 92 based on information such as eruption warnings that may cause volcanic ash to fall.

[0068] Furthermore, in the above embodiment, the ash intrusion suppression members 12 and 62 were moved by operating the drive units 42 and 92, but the ash intrusion suppression members 12 and 62 may also be moved manually by an operator.

[0069] Furthermore, in the second embodiment described above, the volcanic ash intrusion prevention mechanism 60 was attached to the rooftop 202 of the structure 200, but it may also be attached to the outer wall 204 of the structure 200, etc. [Explanation of symbols]

[0070] 10 Volcanic ash intrusion prevention mechanism 12 Ash intrusion suppression member 34 Sheet material 36 Umbrella section 36a Outer edge 38 Banner section 60 Volcanic ash intrusion prevention mechanism 62 Ash intrusion suppression member 84 Sheet material 86 Umbrella section 86a Protruding edge (an example of an outer edge) 88 Banner section 100a outside air intake 110a Inlet 204a Outside air intake 210a Inlet

Claims

1. An ash intrusion suppression member is provided that can move between an deployed position, which covers the outside air intake from above when deployed, and a stored position, which allows a large amount of outside air to be taken in through the outside air intake when retracted. Equipped with a mechanism to prevent volcanic ash intrusion.

2. The ash intrusion suppression member has a sheet-like sheet member, With the ash intrusion suppression member moved to the deployed position, The sheet member comprises an umbrella portion that covers the outside air intake in an umbrella shape from above, and a curtain portion that hangs down from the outer edge of the umbrella portion to below the outside air intake, with an inlet for introducing outside air formed at its lower end. The volcanic ash intrusion prevention mechanism according to claim 1.

3. The opening area of ​​the aforementioned inlet is made larger than the opening area of ​​the aforementioned outside air intake. The volcanic ash intrusion prevention mechanism according to claim 2.

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