JP3049638B2 - High temperature butterfly valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a butterfly valve used for a high-temperature fluid.

[0002]

2. Description of the Related Art Conventionally, the seat surface of a butterfly valve used for high-temperature fluids often uses an elastic seat ring using heat-resistant rubber, a metal spring, or the like, and such an elastic seat ring cannot be used. In the high temperature range, metal sheets were generally used.

[0003]

However, in the above-described conventional type, when a metal sheet is used, when the fluid temperature changes in a closed state, thermal expansion occurs between the valve surface of the valve box and the valve surface of the valve body. A difference occurs. As a result, leakage occurred due to deformation or excessive stress applied to each sheet surface.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide a high-temperature butterfly valve having a stable seal against a temperature change of a high-temperature fluid in a closed state.

[0005]

According to a first aspect of the present invention, there is provided a butterfly valve for high temperature, wherein a valve box side seat portion is provided on an inner peripheral surface of a flow path in a valve box, and a shaft of a valve shaft is provided. A butterfly valve provided with a valve body-side seat portion that presses against the valve box-side seat portion in a closed position on a valve body that is rotatable around a center,
The valve body has a double structure with an outer valve body and an inner valve body provided inside the outer valve body, and between the outer valve body and the inner valve body, the outer valve body and the inner valve body An elastic body which holds a gap formed therebetween and is elastically deformable in the opening / closing direction is provided, and the valve body side seat portion is provided on a peripheral portion of the outer valve body.

The high temperature butterfly valve according to the second aspect of the present invention allows a cooling fluid to flow through a gap formed between the inner valve body and the outer valve body.

[0007]

According to the structure of the first aspect of the invention, by rotating the valve stem and rotating the valve body around its axis, the valve body side seat portion presses against the valve box side seat portion and the valve body closes. Can be In the closed state, when the temperature of the fluid changes, a thermal expansion difference occurs between the valve body side seat and the valve box side seat,
Deformation such as distortion occurs or local stress is applied. At this time, the elastic body is elastically deformed in the opening / closing direction and the gap between the outer valve body and the inner valve body expands and contracts, so that the outer valve body can be displaced with respect to the inner valve body. Such a displacement of the outer valve body absorbs the difference in thermal expansion, so that local stress is prevented from being generated, and the valve body side seat portion is securely pressed against the valve box side seat portion. Therefore, it is possible to prevent a gap from being generated between the valve body-side seat portion and the valve box-side seat portion, thereby preventing leakage.

According to the structure of the second aspect of the present invention, since the inner valve body and the outer valve body can be cooled by the cooling fluid, the inner valve body and the outer valve body are expensive special materials for high temperature, respectively. And the thickness of the inner valve body and the outer valve body can be reduced. Thereby, weight reduction and cost reduction can be achieved. Further, since the elastic body can be cooled by the cooling fluid, the elastic body can be used even in a high temperature region where the elastic body could not be used conventionally.

[0009]

An embodiment of the present invention will be described below. Figure 1
As shown in FIG. 2, a valve box side seat portion 3 is provided on an inner peripheral surface of a flow path 2 formed inside the valve box 1. Further, a valve body 5 that is rotatable around the axis of the valve rod 4 is provided inside the valve box 1. The valve element 5 includes an outer valve element 5a.
And an inner valve element 5b provided inside the outer valve element 5a, to form a double structure.

The outer valve body 5a is formed in a disk shape and has a hollow portion in which the inner valve body 5b can be housed. Further, the outer valve body 5a has a front and back divided structure of one disk portion 6 and the other disk portion 7, and a plurality of these one disk portion 6 and the other disk portion 7 are provided. The outer valve body 5a is formed by fastening with the screw 8 of FIG. The outer valve body 5a
Is provided with a valve body-side seat portion 9 which is in pressure contact with the valve box-side seat portion 3 at the closed position. The inner valve element 5b is also formed in a disk shape, and a gap 10 is formed between the inner valve element 5b and the outer valve element 5a.

[0011] Between the outer valve body 5a and the inner valve body 5b,
A pair of leaf springs 13 (an example of an elastic body) which hold the gap 10 and are elastically deformable in the opening and closing direction are provided on the front and rear sides of the valve stem 4 as a center. The two leaf springs 13 are each formed in a ring shape, and the outer peripheral end of each leaf spring 13 is fitted into a concave step 14 formed on the inner peripheral edge of the outer valve body 5a. Is fitted into a concave step 15 formed on the outer peripheral edge of the inner valve body 5b. Double leaf spring
13, the outer valve body 5a is positioned at the reference position S with respect to the inner valve body 5b.
Is held. When the valve is closed, the valve body 5 is set to be fully closed with a torque that does not cause the leaf spring 13 to be completely deformed.

The valve stem 4 is formed in a pipe shape, and is provided so as to pass through the center of the outer valve body 5a and the inner valve body 5b. An inlet 17 for cooling air 16 is formed at one end of the valve stem 4, an outlet 18 is formed at the other end, and a cooling air flowing through the cooling air 16 is provided inside the valve stem 4. The passage 19 is formed in the axial direction. In addition, the valve stem 4 includes the cooling passage.
Cooling holes 20a, 20b, which communicate with 19 and the outer peripheral surface of the valve stem 4.
20c and 20d (hereinafter referred to as 20a to 20d) are formed at four locations in the circumferential direction and at four locations in the axial direction. One end of the inner valve body 5b is connected to each cooling hole 20a.
20d, the other end of which is open to the outer peripheral surface of the inner valve body 5b, and one end of which has cooling holes 20a-20d.
And a cooling passage 22 whose other end is opened on the front and back surfaces of the inner valve body 5b. The above inlet
A supply pipe 23 for supplying cooling air 16 from the outside is connected to 17, and a recovery pipe 24 for recovering the cooling air 16 is connected to the outlet 18. Also, the cooling channel
Reference numeral 19 designates a supply side A and a discharge side B in the axial direction by a partition plate 25.
And is divided into. Of the cooling holes 20a to 20d, a cooling hole 20a is provided in a range on the supply side A, and cooling holes 20b, 20c, and 20d are provided in a range on the discharge side B.

The operation of the above configuration will be described below.
Normally, by rotating the valve stem 4 and rotating the valve element 5 about the axis thereof, the valve element-side seat portion 9 is pressed against the valve box-side sheet portion 3 and the valve element 5 is closed. At this time, as shown in FIG. 1, the outer valve body 5a is held at the reference position S with respect to the inner valve body 5b by the urging force of both leaf springs 13.

If the temperature of the fluid changes in the closed state, a difference in thermal expansion occurs between the valve body-side seat portion 9 and the valve box-side seat portion 3, causing deformation such as distortion or applying local stress. Or At this time, as shown in FIG.
Since the gaps 10 expand and contract in the opening and closing directions, respectively, the outer valve element 5a can be displaced in the opening and closing direction from the reference position S with respect to the inner valve element 5b. Such outer valve body 5
Since the difference in thermal expansion absorbs the difference in thermal expansion, local stress is prevented from being generated, and the valve body-side seat portion 9 is securely pressed against the valve box-side seat portion 3. Therefore, it is possible to prevent a gap from being formed between the valve body-side seat portion 9 and the valve box-side seat portion 3, thereby preventing the occurrence of leakage.

Further, by rotating the valve rod 4 in the reverse direction and rotating the valve element 5 in the reverse direction about the axis thereof, the valve element-side seat portion 9 is provided.
Is separated from the valve box side seat portion 3, and the valve element 5 is opened.
At this time, since the two leaf springs 13 return to their original postures, the outer valve body 5a returns to the reference position S without shifting with respect to the inner valve body 5b.

As shown in FIG. 1 and FIG.
The cooling air 16 supplied to the cooling flow path 19 from the inlet 17 is divided by the partition plate 25 in the middle of the cooling flow path 19 and flows into the cooling hole 20a located on the supply side A, Cooling hole
The air flows from the cooling passages 21 and 22 into the gap 10. Thereafter, the cooling air 16 flows from the gap 10 into the cooling passages 21 and 22 located on the discharge side B, and the cooling air 20 and the cooling holes 20b and
After flowing into the discharge side B of the cooling flow path 19 via 20c and 20d, it is recovered from the outlet 18 through the recovery pipe 24. in this way,
The cooling air 16 is supplied to the inside of the valve rod 4 and the inside of the inner valve body 5b.
In addition, since the fluid flows into the gap 10 between the outer valve body 5a and the inner valve body 5b, the valve stem 4, the inner valve body 5b, the outer valve body 5a, and the two leaf springs
13 is cooled. Therefore, the valve stem 4 and the inner valve body 5
It is not necessary to use expensive special materials for high temperature for the b, the outer valve body 5a and the leaf springs 13, and the thickness of the inner valve body 5b and the outer valve body 5a can be reduced. Thereby, weight reduction and cost reduction can be achieved, and the leaf spring 13 can be used even in a high temperature region where the conventional leaf spring could not be used.

In the above embodiment, the cooling holes 20a to 20d and the cooling passages 21 and 22 are formed at four places in the circumferential direction and four places in the axial direction, respectively. The number of the passages 21 and 22 may be increased or decreased according to the size of the valve body 5.

In the above-described embodiment, the leaf spring 13 is used as an example of the elastic body, but a coil spring that can expand and contract in the opening and closing directions may be used. Further, the leaf spring 13 is not limited to a ring-shaped one, and a plurality of arc-shaped ones may be used.

In the above embodiment, the cooling air 16 is used as an example of the cooling fluid. However, the cooling air may be cooled by a gas other than air or a liquid such as water.

[0020]

As described above, according to the first aspect of the present invention, by rotating the valve stem to rotate the valve body around its axis, the valve body-side seat portion presses against the valve box-side seat portion, The valve is closed. When the temperature of the fluid changes in the closed state, a difference in thermal expansion occurs between the valve body-side seat portion and the valve box-side seat portion, and deformation such as distortion occurs or local stress is applied. At this time, the elastic body is elastically deformed in the opening / closing direction and the gap between the outer valve body and the inner valve body expands and contracts, so that the outer valve body can be displaced with respect to the inner valve body. Such a displacement of the outer valve body absorbs the difference in thermal expansion, so that local stress is prevented from being generated, and the valve body side seat portion is securely pressed against the valve box side seat portion. Therefore, it is possible to prevent a gap from being generated between the valve body-side seat portion and the valve box-side seat portion, thereby preventing leakage.

According to the second aspect of the invention, since the inner valve body and the outer valve body can be cooled by the cooling fluid, expensive special materials for high temperature are used for the inner valve body and the outer valve body. The thickness of the inner valve body and the outer valve body can be reduced. Thereby, weight reduction and cost reduction can be achieved. Further, since the elastic body can be cooled by the cooling fluid, the elastic body can be used even in a high temperature region where the elastic body could not be used conventionally.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a valve body of a high-temperature butterfly valve according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a valve body of the butterfly valve for high temperature.

FIG. 3 is a cross-sectional view of the valve body of the butterfly valve for high temperature when a thermal expansion difference is absorbed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve case 2 Flow path 3 Valve case side seat part 4 Valve stem 5 Valve body 5a Outer valve body 5b Inner body 9 Valve body side seat part 10 Air gap 13 Leaf spring (elastic body) 16 Cooling air (Cooling fluid)

Claims (2)

(57) [Claims] 1. A valve box-side seat portion is provided on an inner peripheral surface of a flow path in a valve box, and is pressed against a valve body rotatable around the axis of a valve rod with the valve box-side seat portion in a closed position. A butterfly valve provided with a valve body side seat portion, wherein the valve body has a double structure with an outer valve body and an inner valve body provided inside the outer valve body, and the outer valve body and the inner valve body Between the outer valve body and the inner valve body, an elastic body elastically deformable in the opening and closing direction is provided, and the valve body side seat portion is provided at a peripheral portion of the outer valve body. A butterfly valve for high temperature. 2. The high-temperature butterfly valve according to claim 1, wherein a cooling fluid flows through a gap formed between the inner valve body and the outer valve body.