JPH1089497A - Gate valve for high temperature - Google Patents

Abstract

(57) [Problem] To provide a high-temperature gate valve comprising a valve box composed of an outer cylinder and an inner cylinder having a valve box flow passage that is loosely fitted in the outer cylinder. Reduce temperature rise. SOLUTION: The surface of the component facing the outer peripheral surface of the inner cylinder 4, that is, the inner peripheral surface of the outer cylinder 2, or the inner cylinder 4 with respect to the outer cylinder 2 is provided.
Is applied to the surface of the ring-shaped spring 12 holding the heat-insulating material and the surfaces of the heat insulating material cases 20 and 21. Since the amount of radiant heat transfer from the inner cylinder 4 to the outer cylinder 2 and the spring 12 is reduced, the temperature of the outer cylinder 2 and the spring 12 is lower than that of the conventional gate valve, and the allowable stress is increased. Is uniform, and the thermal stress is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A conventional general gate valve has a structure as shown in FIG. 2, which absorbs a dimensional change of a valve box 42 and the like accompanying a change in fluid temperature and a heat transfer coefficient of the fluid. Therefore, in the closed state, the valve seat 43 and the valve body 44 may bite and cause malfunction.

For this reason, the present inventors have previously proposed a high temperature gate valve as shown in FIG. This gate valve is a valve box
The outer cylinder 49 comprises an outer cylinder 49 and an inner cylinder 50, and a ring-shaped spring 51 for holding the inner cylinder 50 with respect to the outer cylinder 49 is provided between the outer cylinder 49 and the inner cylinder 50. It is provided so as to be connected to the peripheral portion and the outer peripheral portion of the inner cylinder 50. 43 is a valve seat, and 44 is a valve body. According to this configuration, between the outer cylinder 49 and the inner cylinder 50 of the valve box 42 or the valve box 42
When a difference in thermal expansion or contraction occurs between the upstream side and the downstream side of the valve, the difference in thermal expansion or contraction can be absorbed by the deflection of the spring 51, thereby preventing the valve box 42 from being overly distorted. And stable sealability and operability can be realized.

[0004]

However, even in the high-temperature gate valve described above, the temperature of the spring 51 and the outer cylinder 49 is increased by convection heat and radiant heat generated from the inner cylinder 50 to the outer cylinder 49. May rise and plastic deformation may occur.

An object of the present invention is to solve the above problems and to provide a high-temperature gate valve capable of reducing a rise in temperature of members other than the inner cylinder.

[0006]

In order to solve the above-mentioned problems, a high-temperature gate valve according to claim 1 of the present invention comprises:
In a high-temperature gate valve composed of an outer cylinder and an inner cylinder having a valve box flow passage that is loosely fitted in the outer cylinder, heat insulation is provided on the surface of a component such as an outer cylinder facing the outer peripheral surface of the inner cylinder. It is coated.

According to a second aspect of the present invention, there is provided a high-temperature gate valve comprising a ring-shaped elastic body provided between the outer cylinder and the inner cylinder for holding the inner cylinder relative to the outer cylinder, and an inner peripheral portion of the outer cylinder and the inner cylinder. The elastic body is provided with a thermal barrier coating on the surface thereof.

According to a third aspect of the present invention, there is provided a gate valve for high temperature, wherein a heat insulating material case in which a heat insulating material is accommodated is disposed between an outer cylinder and an inner cylinder, and a thermal barrier coating is provided on a surface of the heat insulating material case. It was done.

According to the above configuration, the amount of radiant heat transferred from the inner cylinder to the components such as the outer cylinder and the elastic body is reduced by the thermal barrier coating. As a result, compared to the case without thermal barrier coating, the temperature of the components such as the outer cylinder and elastic body is lower, the allowable stress is larger, and the temperature of the inner cylinder is more uniform, reducing the thermal stress. Is done.

[0010] Further, by not being exposed to the high-temperature fluid by the heat insulating material case sealed between the outer cylinder and the inner cylinder,
The temperature rise of the outer cylinder and the elastic body is suppressed, and the thermal insulation coating is applied to this heat insulating material case, so that the temperature rise of the outer cylinder and the elastic body is further suppressed.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. The high temperature gate valve shown in FIG.
Has almost the same configuration as the conventional high-temperature gate valve shown in
The valve case 1 includes an outer case 2 and an inner case 4 having a valve case passage 3 which is loosely fitted inside the outer case 2. At the center of the outer cylinder 2 is provided a cylindrical valve body storage section 6 having a valve body storage space 5 inside.

A valve body 8 is provided inside the valve box 1 and fixed to a valve rod 7 inserted into the valve body storage space 5, and the valve body 8 is provided on an end surface of a central portion of the inner cylinder 4. Opening and closing movement is possible between the valve seats 9, 9 and the valve body storage space 5. Valve stem 7
Is connected to a driving device (not shown) provided at an end of the valve element housing portion 6 in an interlocked manner.

On both end surfaces of the outer cylinder 2, there are formed disk-shaped end walls 10 projecting from the inner peripheral surface of the outer cylinder 2 to the outer peripheral surfaces of both ends of the inner cylinder 4 toward the center. A pair of disk-shaped intermediate walls 11 projecting outward from the inner peripheral surface of the outer cylinder 2 is formed on the outer peripheral surface of the central part of the inner cylinder 4. The distance between the two intermediate walls 11 is substantially the same as the width of the valve housing space 5 in the flow direction.

A pair of ring-shaped springs 12 for holding the inner cylinder 4 with respect to the outer cylinder 2 are fitted between the outer cylinder 2 and the inner cylinder 4. The inner peripheral portion of the spring 12 is in contact with a first mounting portion 13 formed over the entire outer peripheral surface of the inner cylinder 4 and projecting outward, and is sealed over the entire periphery via an annular first packing 14. Have been. The outer peripheral portion of the spring 12 is in contact with a second mounting portion 15 formed on the inner peripheral surface of the outer cylinder 2 over the entire periphery and protruding inward. Sealed over.

As the first packing 14, a graphite-based (eg, graphite) packing having a low thermal conductivity is used, and as the second packing 16, a metal-based packing having a high thermal conductivity is used. The inner peripheral portion of the spring 12 is connected to the first through a plurality of countersunk screws 17.
Connected to the mounting part 13, the outer periphery of the spring 12 has a plurality of flathead screws.
It is connected to the second mounting portion 15 via 17.

Between the outer cylinder 2 and the inner cylinder 4, an inner peripheral surface of an end of the outer cylinder 2, an outer peripheral surface of an end of the inner cylinder 4, and an end wall 10 opposed to each other.
And a first heat insulating material storage space 18 surrounded by the spring 12 and formed around the entire circumference.
The outer peripheral surface of the central part of the inner cylinder 4, the opposing intermediate wall 11 and the spring
12, a second heat insulating material storage space 19 is formed over the entire circumference. The first heat insulating material storage space 18 and the second heat insulating material storage space 19 store a first heat insulating material case 20 and a second heat insulating material case 21 storing glass wool, respectively.

The surface of the member facing the outer peripheral surface of the inner cylinder 4, that is, the inner peripheral surface of the outer cylinder 2 including the valve element housing portion 6 and the second mounting portion 15, the inner surface of the end wall 10, and the spring 12 Surface, and the first
A thermal barrier coating 22 made of zirconia-based ceramic is applied to the surfaces of the heat insulating material case 20 and the second heat insulating material case 21.

The operation of the above configuration will be described below.
A high-temperature fluid flows through the valve case flow path 3 and changes between the fluid temperature and the heat transfer coefficient of the fluid between the inner cylinder 4 and the outer cylinder 2 or between the upstream and downstream of the inner cylinder 4 and the outer cylinder 2. If a difference in thermal expansion or contraction occurs between the side and the side, the spring 12 bends and absorbs the difference in thermal expansion or contraction, thereby preventing the valve box 1 from being overly distorted. For this reason, stable sealing performance and operability can be maintained.

At this time, since the thermal barrier coating 22 is applied, the amount of radiant heat transfer from the inner cylinder 4 to the outer cylinder 2 and the spring 12 is reduced as compared with the case where the thermal barrier coating 22 is not applied. The temperatures of the outer cylinder 4 and the spring 12 become lower, the allowable stress becomes larger, and the temperature of the inner cylinder 4 becomes uniform, so that the thermal stress is reduced.

Further, first and second heat insulating material cases 20, 21 are arranged between the inner cylinder 4 and the outer cylinder 2, and the first and second heat insulating material cases 20, 21 are provided with a thermal barrier coating. Therefore, the heat transfer to the outer cylinder 2 and the spring 12 is further reduced, and the temperature rise is further suppressed.

Furthermore, since the heat conductivity of the first packing 14 is low, the heat of the inner cylinder 4 is hardly transmitted to the spring 12, and the heat conductivity of the second packing 16 is high, so that the heat of the spring 12 is
It escapes to the outer cylinder 2 through 16. This also suppresses the temperature rise of the spring 12.

Therefore, the design temperature of the spring 12 and the outer cylinder 2 can be lowered, and the design is simplified. The zirconia-based ceramic used for the thermal barrier coating 22 in the above configuration is a suitable thermal barrier coating material because it has high heat resistance, low thermal conductivity, high emissivity, and is chemically stable. However, other heat-shielding coating materials may be used.

Although glass wool is used as the heat insulating material, an air layer or a castable refractory material may be used.

[0024]

As described above, according to the present invention, the amount of radiant heat transfer from the inner cylinder to the outer cylinder and the elastic body can be reduced by applying the thermal barrier coating. Therefore, since the temperature of the outer cylinder and the elastic body can be lowered, the allowable stress can be increased, and the temperature of the inner cylinder can be made uniform, so that the thermal stress can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a partial sectional view of a conventional gate valve.

FIG. 3 is a cross-sectional view of a conventional gate valve in which a difference in thermal expansion or contraction is absorbed by a ring-shaped elastic body that holds an inner cylinder with respect to an outer cylinder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve case 2 Outer case 3 Valve case flow path 4 Inner case 12 Spring (elastic body) 22 Thermal barrier coating

Claims (3)

[Claims] 1. A high-temperature gate valve comprising a valve box comprising an outer cylinder and an inner cylinder having a valve box flow passage loosely fitted in the outer cylinder, wherein the outer cylinder opposes the outer peripheral surface of the inner cylinder. A high-temperature gate valve characterized in that a thermal barrier coating is applied to the surface of a component such as the above. 2. A ring-shaped elastic body for holding the inner cylinder with respect to the outer cylinder is provided between the outer cylinder and the inner cylinder so as to be connected to the inner periphery of the outer cylinder and the outer periphery of the inner cylinder. 2. The high-temperature gate valve according to claim 1, wherein a thermal barrier coating is applied to a surface of the elastic body. 3. A heat insulating material case in which a heat insulating material is accommodated is disposed between an outer cylinder and an inner cylinder, and a thermal barrier coating is applied to a surface of the heat insulating material case. 1
Or the high temperature gate valve according to any one of claims 2 to 4.