JP3095635B2 - 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 high-temperature butterfly valve used for controlling a high-temperature gas flow.

[0002]

2. Description of the Related Art A high-temperature butterfly valve conventionally used for controlling a high-temperature and high-pressure gas flow is as shown in FIG. A disk-shaped valve element 3 capable of opening and closing the flow path is arranged, and the valve element 3 is configured to be opened and closed and rotated by a valve rod 4 that penetrates the valve element 3 in the diameter direction. A heat-resistant material that can withstand a predetermined temperature and pressure is used.

A heat insulating material layer 5 is disposed on the inner periphery of the valve box 2, and an inner cylinder 6 made of a heat-resistant material is disposed on the inner periphery of the heat insulating material layer 5. The strength of the valve box 2 is secured without lowering the thermal efficiency, and the heat insulating material is prevented from flowing downstream by the inner cylinder 6. The valve box 2 and the inner cylinder 6 are connected to each other by bolting annular flanges 7 and 8 projecting from the inner periphery of the valve box and the outer periphery of the inner cylinder, respectively, and are connected via the flanges 7 and 8. Thereby, the difference in thermal expansion between the valve box 2 and the inner cylinder 6 is absorbed.
Numeral 9 denotes a valve seat protrusion which is brought into close contact with the outer peripheral edge when the valve body 3 is rotated to the closed position, and 10 is a holding plate for preventing the heat insulating material layer 5 from falling off.

[0004] A cooling passage 11 is formed at the axis of the valve stem 4, and by flowing a cooling medium through the cooling passage 11, the strength of the valve stem 4 is maintained and heat is transmitted to the opening / closing mechanism. Preventing.

[0005]

However, in the high-temperature butterfly valve as described above, the flange 7 on the inner periphery of the valve box may be locally at a high temperature, and at this time, radial expansion is hindered. As a result, there is a problem that large thermal stress is generated at two locations of the inner peripheral portion 7a and the base portion 7b of the flange 7, which is a strength member.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to suppress a local temperature rise of a valve box and to reduce thermal stress generated in an inner peripheral portion and a base portion of a flange on an inner peripheral portion of the valve box. It is assumed that.

[0007]

In order to solve the above-mentioned problems, a high-temperature butterfly valve according to the present invention has a heat insulating material layer disposed on an inner periphery of a valve box, and a heat-resistant material disposed on an inner periphery of the heat insulating material layer. A high-temperature butterfly valve in which a valve box and an inner cylinder are connected by superimposing flanges projecting from the inner circumference of the valve box and the outer circumference of the inner cylinder, respectively. a hollow portion provided in the set flanges the circumferential direction, in this hollow portion, a lower melting point than the valve housing material, and in which the thermal conductivity in the molten state is filled with thermal conductivity greater than the metal in the solid state.

[0008]

According to the above construction, when the temperature of the valve box becomes high, the metal sealed in the hollow portion of the flange on the inner periphery of the valve box becomes molten, and the molten metal is coupled with the convection to generate heat. Since the rate increases, heat conduction is performed to the entire flange and the entire valve box, thereby reducing the temperature difference in the entire valve box and reducing the Young's modulus of the entire flange in a molten state of metal. As a result, the thermal stress at the inner peripheral portion and the base portion of the flange is reduced.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. The overall configuration of the high-temperature butterfly valve of the present invention is substantially the same as the conventional one described with reference to FIG.

FIG. 1 is a cross-sectional view of a valve case which is a characteristic structure of the present invention. The valve case 2 has connection flanges 1 protruding at the outer periphery of both ends, and has an inner periphery for connection with an inner cylinder. A flange 7 protrudes. Here, the valve box 2 of the present embodiment is different from the conventional one in that a hollow portion 12 long in the radial direction is provided in the flange 7 on the inner circumference of the valve box over the circumferential direction.
In addition, metallic sodium 13 whose melting point is lower than that of the valve box material and whose thermal conductivity in the molten state is higher than that in the solid state
Is that a metal such as

In such a configuration, when the high temperature fluid flows through the internal flow path of the high temperature butterfly valve and the temperature of the valve box 2 becomes high, the metallic sodium 13 sealed in the hollow portion 12 of the flange 7 is in a molten state. The metallic sodium 13 in the molten state has an increased thermal conductivity. When a chromoly material is used as the valve box material, the metallic sodium 13 is about 2 times larger than the valve box 2.
It will have twice the thermal conductivity. Since convection occurs in the molten metallic sodium 13, the substantial thermal conductivity is further increased, and heat conduction is rapidly performed to the flange 7 and thus the entire valve box 2, and the temperature difference in the entire valve box 2 is increased. Is reduced, and the maximum temperature of the valve box 2, that is, the temperature of the inner end of the flange 7 is reduced. At this time, in the molten state of the metallic sodium 13, the Young's modulus of the entire flange 7 becomes small. From these, the inner peripheral portion 7a of the flange 7
And the occurrence of thermal stress in the base 7b is smaller than in the prior art. In this embodiment, since the metallic sodium 13 is sealed in the hollow portion 12 of the flange 7, the temperature of the entire valve box 2 is reduced by about 10%, and the thermal stress in the inner peripheral portion 7a and the base portion 7b of the flange 7 is reduced by about 10%. It has been reduced by 20%.

[0012]

As described above, according to the present invention, a hollow portion is provided circumferentially in a flange formed on the inner periphery of the valve box for connection with the inner cylinder, and the hollow portion has a melting point higher than that of the valve box material. By encapsulating a metal which has a low thermal conductivity and which has an increased thermal conductivity by melting, the temperature difference in the entire valve box can be reduced, and the thermal stress generated in the inner peripheral portion and the base portion of the flange can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a vertical cross-sectional view perpendicular to a valve shaft of a conventional high-temperature butterfly valve.

[Explanation of symbols]

 2 Valve box 7 Flange 12 Hollow section 13 Metallic sodium

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16K 1/16-1/226 F16K 27/02 F16K 51/00

Claims (1)

(57) [Claims] 1. A heat insulating material layer is provided on an inner periphery of a valve box, and an inner cylinder made of a heat-resistant material is provided on an inner periphery of the heat insulating material layer. And a high-temperature butterfly valve connected by superimposing flanges protruding on the outer periphery of the inner cylinder, respectively, and providing a hollow portion in the circumferential direction on the flange protruding on the inner periphery of the valve box. The melting point is low and the thermal conductivity in the molten state is in the solid state
A high-temperature butterfly valve characterized by enclosing a metal having a higher thermal conductivity .