JPH0536168U - Butterfly valve - Google Patents

Abstract

(57) [Summary] [Purpose] To withstand high temperatures without lowering thermal efficiency by cooling the valve box. [Structure] A heat insulating material layer 4 is arranged on the inner circumference of the valve box 3, and an inner cylinder 5 made of a heat-resistant material is arranged on the inner circumference of the heat insulating material layer 4 to heat the valve box 3 and to cool the inner cylinder 5 Prevents the heat insulating material from flowing downstream. Also, to absorb the difference in thermal expansion,
Flange 8 on the inner circumference of valve box 3 and flange 9 on the outer circumference of inner cylinder 5
Are superposed and bolted to connect the valve box 3 and the inner cylinder 5,
A sliding material is provided on the overlapping surface of the flanges 8 and 9.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a butterfly valve, and more particularly to a butterfly valve for high temperature used for controlling hot gas flow.

[0002]

[Prior Art]

 Conventionally, a butterfly valve used to control a high-temperature gas flow of about 650 to 750 ° C has a disc-shaped valve body 32 that can open and close its flow path inside a valve box 31, as shown in Fig. 4. The structure is similar to that of a normal butterfly valve in which the valve body 32 is opened and closed by a valve rod 33 penetrating the valve body 32 in the diameter direction, and a heat-resistant material capable of withstanding a predetermined temperature and pressure is used as a material thereof. It is used. In the case of the temperature as described above, it was possible to deal with it by using a high-grade material which is relatively high in marketability.

In addition, a cooling medium such as steam is circulated in the cooling passage 35 formed at the axial center of the valve rod 33 in order to efficiently cool it by utilizing convective heat transfer and vaporization heat. The strength of the valve rod 33 is maintained and heat is prevented from being transmitted to the opening / closing mechanism.

[0004]

[Problems to be solved by the device]

 However, if an attempt is made to apply it to a gas flow of high temperature and high pressure, the required strength will exceed the limit of the practical design strength of the material, so it is necessary to adopt a structure that incorporates a heat insulation or cooling structure.

Therefore, in order to secure the strength of the valve box, it may be considered to attach a heat insulating material to the inner surface of the valve box, but there arises a problem that the heat insulating material may be blown to the downstream by the flow of the internal fluid. In addition, if the valve box is steam-cooled, the thermal efficiency will decrease, causing a problem.

In view of the above conventional problems, an object of the present invention is to provide a butterfly valve that can withstand high temperatures without lowering thermal efficiency.

[0007]

[Means for Solving the Problems]

 The present invention is characterized in that a heat insulating material layer is arranged on the inner circumference of the valve box, and an inner cylinder made of a heat resistant material is arranged on the inner circumference of the heat insulating material layer.

[0008] Preferably, the flanges protruding from the inner circumference of the valve box and the outer circumference of the inner tube are overlapped with each other, and the valve box and the inner cylinder are connected by bolt connection, and a sliding member is interposed between the overlapping surfaces of the flanges. ..

[0009]

[Action]

 According to the configuration of the present invention, since the heat insulating material layer is arranged on the inner circumference of the valve box to insulate the valve box from high temperature internal fluid, the strength of the valve box is ensured without lowering the thermal efficiency. In addition, since the inner cylinder is arranged on the inner circumference of the heat insulating material layer, there is no fear that the heat insulating material will flow downstream due to the flow of the internal fluid, and the inner cylinder is not a strength member that supports pressure. Since there is no such material, a heat-resistant material having high marketability can be used as the material of the inner cylinder.

Further, by connecting the valve box and the inner cylinder by overlapping the flanges protruding from each other, it is possible to easily absorb the difference in thermal expansion between the valve box and the inner cylinder, and between the overlapping surfaces. By interposing the sliding member, the difference in thermal expansion can be absorbed more smoothly.

[0011]

【Example】

 Hereinafter, a butterfly valve according to an embodiment of the present invention will be described with reference to FIGS. Reference numeral 1 is a butterfly valve for high temperature, in which a heat insulating material layer 4 having a predetermined thickness is provided on the inner circumference of a valve box 3 having connecting flanges 2 projecting on the outer circumferences of both ends, and is concentric with the valve box 3 on the inner circumference. An inner cylinder 5 is arranged in the. A valve body 6 is arranged at a central position in the inner cylinder 5 in the axial direction. The valve body 6 is fixed to a valve rod 7 rotatably supported around an axis perpendicular to the axes of the valve box 3 and the inner cylinder 5.

At a position at an appropriate distance from the axial center position of the valve rod 7 in the axial direction of the valve box 3 and the inner cylinder 5, a flange 8 is projectingly provided on the inner circumference of the valve box 3, and the flange 8 is formed on the outer circumference of the inner cylinder 5. An overlapping flange 9 is provided on the outer surface of the flange 8. These flanges 8 and 9 are provided at a proper distance from the axial center of the valve rod 7, and do not interfere with the valve rod 7 penetrating portion of the valve box 3 and the inner cylinder 5, so they are formed continuously in an annular shape. And a gasket 10 also serving as a sliding material is interposed between the overlapping surfaces. The flanges 8 and 9 are fastened to each other with bolts, and the inner cylinder 5 is supported by the valve box 3 by this. Further, since the flanges 8 and 9 are formed at positions axially distant from the axial center position of the valve rod 7, that is, the valve body 6, the valve body 6 and the valve body 6 are separated from each other due to the difference in thermal expansion between the inner cylinder 5 and the valve box 3. The overlapping surface is formed into a tapered surface with a predetermined inclination angle so that no positional deviation occurs between the inner cylinders 5. The inclination angle is determined by the amount of radial displacement of the flange 9 due to the relative thermal expansion of the inner cylinder 5 with respect to the valve box 3, the axial center position of the valve body 6 and the axis of the inner cylinder 5 between the flange 9. It is set corresponding to the ratio with the thermal expansion amount in the core direction. Reference numeral 11 denotes a valve seat formed on the inner circumference of the inner cylinder 5 so that when the valve body 6 is rotated to a closed position perpendicular to the axis of the inner cylinder 5, the outer peripheral edge portion of the valve body 6 comes into close contact with the inner circumference of the inner cylinder 5. It is a protrusion.

A holding plate 12 is provided on the inner circumference of both ends of the valve housing 3 so as to prevent the heat insulating material layer 4 from falling out. A cylindrical refrigerant passage 13 having a small flow passage cross-sectional area is formed in the shaft core of the valve rod 7 by disposing a round rod or a pipe at the center of the passage having a round hole shape.

The valve rod 7 penetrates the seal rings 14 a and 14 b provided in the valve rod penetrating portion of the inner cylinder 5, and further penetrates the bearing tubular portions 15 a and 15 b provided in the valve box 3 so that both ends thereof are It projects to the outside. Reference numerals 16 and 17 denote bearing members of the valve rod 7 arranged in the tubular bearing portions 15a and 15b. In addition, shaft sealing devices 18a and 18b that prevent fluid from leaking outside from the gaps on the outer circumference of the valve rod 7 are mounted on the outer sides of the bearing cylindrical portions 15a and 15b, and support outer cylinders 19a and 19b are arranged on the outer circumferences thereof. It is set up. A casing 21 of the opening / closing drive means 20 is fixed to a supporting outer cylinder 19a on one end side of the valve rod 7, and a bearing 22 supporting the end of the valve rod 7 is mounted on the supporting outer cylinder 19b on the other end side of the valve rod 7. It is fixed.

The opening / closing drive means 20 is a rotary lever 25 having a boss 24 fixed to the valve rod 7 and rotatably supported by a casing 21 via a bearing 23, and a support shaft 27 to connect the casing 21 to the casing 21. The cylinder device 26 is swingably supported, and the tip of the piston rod of the cylinder device 26 is connected to the rotating lever 25.

A means (not shown) for supplying steam toward the refrigerant passage 13 is connected to one end of the valve rod 7. In the above configuration, the valve body 6 is opened and closed by the rotation lever 25 being rotated by the expansion and contraction operation of the cylinder device 26 and the valve rod 7 being rotated.

When a high-temperature fluid flows in the inner cylinder 5, the inner cylinder 5 becomes high in temperature, but since the valve box 3 has the heat insulating material layer 4 interposed therein, the temperature does not become so high. It is possible to secure the required strength even with the use of various materials, and the inner cylinder 5 becomes hot, but since a large part of the fluid pressure is supported by the valve box 3, large strength is not required, and therefore the market Even if a heat-resistant steel with high marketability is used, it can sufficiently withstand the high temperature. Further, since the inner cylinder 5 is present on the inner circumference of the heat insulating material layer 4, the heat insulating material does not flow downstream due to the flow of the fluid.

On the other hand, since the heat insulating material layer 4 is interposed between the inner cylinder 5 and the valve box 3, a large temperature difference is generated between them and a thermal expansion difference is generated. The difference in thermal expansion between the valve box 3 and the inner cylinder 5 in the axial direction can be appropriately absorbed at the connecting portion with the pipe connected to the butterfly valve 1. The inner cylinder 5 also expands in the radial direction relative to the valve box 3, but as a structure for supporting the inner cylinder 5 by the valve box 3, flanges 8 and 9 projecting from the inner circumference and the outer circumference of the inner cylinder 5 are used as axial cores. Since the structure is such that the flanges 8 and 9 are overlapped with each other and bolted together, the difference in thermal expansion can be absorbed by sliding the mating surfaces of the flanges 8 and 9. At this time, the gasket 10 interposed on the overlapping surface acts as a sliding material, so that thermal expansion can be smoothly absorbed, and excessive stress is locally generated or the inner cylinder 5 is prevented from being deformed. it can.

Further, the flanges 8 and 9 are arranged so as to be displaced from the axial center position of the valve rod 7, and are formed in a continuous annular shape over the entire circumference, and the gasket 10 is interposed on the overlapping surface thereof. It is possible to completely prevent the flow of the fluid flowing between the valve box 3 and the inner cylinder 5. In addition, since the overlapping surfaces of the flanges 8 and 9 are tapered surfaces having the above-described predetermined inclination angles, the bearing cylinder portions 15a and 15b of the valve box 3 and the valve seat protrusion 11 of the inner cylinder 5 and the seals due to the difference in thermal expansion. There is no misalignment between the rings 14a and 14b, and even if a difference in thermal expansion occurs, the valve body 6 and the valve seat protrusion 11 are kept in close contact with each other and the valve rod 7 is smoothly rotated. To be done.

Further, the valve rod 7 can be effectively cooled by supplying steam or the like as the refrigerant to the refrigerant passage 13 in the shaft core portion of the valve rod 7. Further, since the refrigerant passage 13 is formed in a tubular shape to reduce the flow passage cross-sectional area without reducing the heat transfer area, it is possible to reduce the steam consumption without reducing the cooling effect.

In the above embodiment, the flanges 8 and 9 are arranged so as to be displaced from the axial center position of the valve rod 7 and formed in a continuous annular shape over the entire circumference. However, depending on the case, the flange 8 and 9 pass through the axial center of the valve rod 7 and the inner cylinder. The flanges 8 and 9 may be formed such that the overlapping surface is located on a plane perpendicular to the axis of the valve 5 and the axis of the valve box 3. In that case, the flanges 8 and 9 are partially formed in a range that does not interfere with the seal rings 14a and 14b and the bearing tube portions 15a and 15b.

[0022]

[Effect of the device]

 According to the present invention, as described above, since the heat insulating material layer is arranged on the inner circumference of the valve box to insulate the valve box from the high temperature internal fluid, the strength of the valve box can be reduced without lowering the thermal efficiency. In addition, since the inner cylinder is arranged on the inner circumference of the heat insulating material layer, there is no fear that the heat insulating material will flow downstream due to the flow of the internal fluid, and the inner cylinder is not a strength member that supports pressure. Since there is no such material, it is possible to use a heat-resistant material having a high marketability as a material for the inner cylinder.

Further, by connecting the valve box and the inner cylinder by overlapping the flanges protruding from each other, it is possible to easily absorb the difference in thermal expansion between the valve box and the inner cylinder, and between the overlapping surfaces. By interposing a sliding material, the effect of more smoothly absorbing the difference in thermal expansion is also exhibited.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view perpendicular to a stem axis of a butterfly valve according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view parallel to the valve stem axis of the embodiment.

FIG. 3 is a side view of the embodiment.

FIG. 4 is a vertical cross-sectional view perpendicular to the valve axis of a conventional butterfly valve.

[Explanation of symbols]

 1 Butterfly valve 3 Valve box 4 Insulating material layer 5 Inner cylinder 8 Flange 9 Flange 10 Gasket also used as a sliding material

Claims (3)

[Scope of utility model registration request] 1. A butterfly valve, wherein a heat insulating material layer is arranged on the inner circumference of a valve box, and an inner cylinder made of a heat resistant material is arranged on the inner circumference of the heat insulating material layer. 2. A butterfly valve, characterized in that flanges projecting from the inner circumference of the valve box and the outer circumference of the inner tube are overlapped with each other and bolted to connect the valve box and the inner tube. 3. The butterfly valve according to claim 2, wherein a sliding material is interposed between the overlapping surfaces of the flange.