JPH094732A - Gate valve for high temperature - Google Patents

Abstract

(57) [Summary] [Structure] The valve casing 1 is composed of an outer casing 2 and an inner casing 4 which is loosely fitted in the outer casing 2 and has a valve casing passage 3.
A ring-shaped spring 11 connected to the inner peripheral portion of the outer cylinder 2 and the outer peripheral portion of the inner cylinder 4 and the heat insulating materials 19 and 20 are fitted between the inner cylinder 4 and the inner cylinder 4, and the spring 11 and the inner cylinder 4 are inserted. The contact portion with the first packing 13 having a low thermal conductivity was sealed, and the contact portion between the spring 11 and the outer cylinder 2 was sealed with the second packing 15 having a high thermal conductivity. [Effect] As the spring 11 bends, the difference in thermal expansion generated between the inner cylinder 4 and the outer cylinder 2 of the valve box 1 is absorbed, so that it is possible to prevent the valve box 1 from being unduly distorted and thus stable. The sealing performance and operability can be maintained. Further, even if the high-temperature fluid flows, the temperature of the spring 11 relatively decreases, so that the design temperature of the spring 11 can be lowered.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, a general sluice valve 41 has a structure which absorbs a dimensional change of a valve box 42 or the like due to a change of a fluid temperature and a heat transfer coefficient of the fluid. Therefore, in the closed state, the valve seat 43 and the valve element 44 may be bitten with each other and malfunction may occur.

In order to solve such a problem, as shown in FIG. 4, the valve element 44 is divided into an upstream side and a downstream side, and one divided valve element 44a and the other divided valve element 44b are divided. A coil spring 45 may be inserted between them. According to this, the valve box changes as the fluid temperature and the heat transfer coefficient of the fluid change.
Even if the dimensions such as 42 change, the above coil spring
Since 45 bends and the space between the split valve bodies 44a and 44b expands and contracts, it is possible to cope with dimensional changes of the valve box 42 and the like.

Further, as shown in FIG. 5, one split valve body
It is conceivable that a hemispherical convex portion 46 is provided on the back surface of the 44a and the convex portion 46 is fitted into the concave portion 47 of the other split valve body 44b.
According to this, the wedge effect of the convex portion 46 and the concave portion 47 is utilized to enable stable seat surface pressure and stable opening / closing operation.

Further, as shown in FIG. 6, by forming notches 48 on the upper and lower sides of the valve body 44, the dimensions of the valve box 42 and the like change in accordance with changes in the fluid temperature and the heat transfer coefficient of the fluid. Even in this case, since the valve element 44 bends, it is possible to cope with the dimensional changes of the valve box 42 and the like.

[0006]

However, in each of the above-mentioned conventional examples, the difference in thermal expansion or contraction between the vicinity of the flow passage 49 inside the valve box 42 and the outer peripheral portion is accompanied by changes in the fluid temperature and the heat transfer coefficient of the fluid. The valve box 42 is distorted forcibly due to a difference or a difference in thermal expansion between the upstream side and the downstream side of the valve box 42, so that the valve body 44 absorbs this distortion.

Therefore, the one shown in FIG. 4 has a problem that there is no optimum material for the coil spring 45 at high temperature. Further, in the case of the one shown in FIG. 5, there is a problem that an excessive surface pressure acts on the contact portion between the convex portion 46 and the concave portion 47 due to the dimensional change of the valve box 42 or the like, and the valve portion is deformed. Further, with respect to the one shown in FIG. 6, there is a problem that a large pulling force is required for the opening operation in a state where the valve body 44 is bent, and the valve body 44 is plastically deformed at a high temperature.

The present invention solves the above problems, and provides a high temperature sluice valve capable of sufficiently absorbing the dimensional change of the valve box due to the change of the fluid temperature and the heat transfer coefficient of the fluid by the structure of the valve box itself. That is the purpose.

[0009]

In order to solve the above problems, a high temperature sluice valve according to the first aspect of the present invention has a valve box, an outer cylinder, and a valve box flow passage loosely fitted in the outer cylinder. An inner cylinder, and a ring-shaped elastic body connected to the inner peripheral portion of the outer cylinder and the outer peripheral portion of the inner cylinder is fitted between the outer cylinder and the inner cylinder to form the outer cylinder and the inner cylinder. A sealing material is provided to seal the space between them.

In the high temperature sluice valve according to the second aspect of the present invention, the sealing material includes the first packing having a low thermal conductivity, which is provided over the entire circumference at the contact portion between the elastic body and the inner cylinder, and the elastic body and the outer cylinder. And a second packing having a high thermal conductivity provided over the entire circumference at the contact portion of.

[0011]

According to the structure of the first aspect of the present invention, a difference in thermal expansion or contraction occurs between the inner cylinder and the outer cylinder of the valve box or the valve box changes as the fluid temperature and the heat transfer coefficient of the fluid change. Even when a difference in thermal expansion occurs between the upstream side and the downstream side, the elastic body bends and absorbs the difference in thermal expansion or contraction, so that it is possible to prevent the valve box from being unduly strained.

According to the structure of the second aspect of the present invention, since the first packing having a low thermal conductivity is provided at the contact portion between the elastic body and the inner cylinder, the heat of the inner cylinder is hard to be transmitted to the elastic body. Further, since the second packing having high thermal conductivity is provided at the contact portion between the elastic body and the outer cylinder, the heat of the elastic body is released to the outer cylinder through the second packing. Therefore, even if the high-temperature fluid flows, the temperature of the elastic body is relatively lowered, and therefore the design temperature of the elastic body can be lowered, so that the material can be easily selected and the design is simplified.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Reference numeral 1 is a valve box, and an outer cylinder 2 and this outer cylinder 2
And an inner cylinder 4 having a valve box flow path 3 loosely fitted therein. Both ends of the outer cylinder 2 have flanges 5
Is provided. At the center of the outer cylinder 2, there is provided a cylindrical valve body storage part 7 having a valve body storage space 6 inside.

On both end faces of the outer cylinder 2, there are formed disc-shaped end walls 8 projecting from the inner peripheral surface of the outer cylinder 2 toward the outer peripheral surfaces of both ends of the inner cylinder 4 toward the center. A pair of disk-shaped intermediate walls 9 projecting outward from the inner peripheral surface of the outer cylinder 2 toward the outer peripheral surface of the outer cylinder 2 are formed on the outer peripheral surface of the central part of the inner cylinder 4. The space between the two intermediate walls 9 is formed to be substantially the same as the flow path width of the valve body housing space 6.

A ring-shaped spring 11 (an example of an elastic body) connected to the inner peripheral portion of the outer cylinder 2 and the outer peripheral portion of the inner cylinder 4 is provided between the outer cylinder 2 and the inner cylinder 4. One pair is fitted. The inner peripheral portion of these springs 11 abuts on a first mounting portion 12 which is formed on the outer peripheral surface of the inner cylinder 4 over the entire circumference and projects outward, and is sealed over the entire circumference via an annular first packing 13. Has been done. Further, the outer peripheral portion of the spring 11 abuts on a second mounting portion 14 which is formed on the inner peripheral surface of the outer cylinder 2 over the entire circumference and protrudes toward the inner peripheral side, and the entire outer peripheral portion of the spring 11 via an annular second packing 15. Sealed all around.

The first packing 13 and the second packing 15 are an example of a sealing material that seals between the outer cylinder 2 and the inner cylinder 4, and the first packing 13 is made of graphite (graphite) having a low thermal conductivity. Etc. are used, and the second packing 15 is made of metal or the like having high thermal conductivity.
The inner peripheral portion of the spring 11 is connected to the first mounting portion 12 via a plurality of countersunk screws 16 and the outer peripheral portion of the spring 11 is provided with a plurality of countersunk screws 16.
It is connected to the second mounting portion 14 via.

The outer cylinder 2 is provided between the outer cylinder 2 and the inner cylinder 4.
The first heat insulating material storage space 17 surrounded by the inner peripheral surface of the end of the inner peripheral surface of the inner cylinder 4, the outer peripheral surface of the inner cylinder 4 and the opposing end wall 8 and the spring 11 is formed over the entire circumference. A second heat insulating material storage space 18 surrounded by the inner peripheral surface of the central portion of the outer cylinder 2, the outer peripheral surface of the central portion of the inner cylinder 4, the intermediate wall 9 and the spring 11 facing each other is formed over the entire circumference. . Each of the first heat insulating material storage space 17 and the second heat insulating material storage space 18 has a first heat insulating material 19.
(Glass wool) and the second heat insulating material 20 (glass wool) are stored.

Inside the valve box 1, a valve body 22 is provided via a valve rod 21 inserted into the valve body housing space 6.
The valve element 22 is openable and closable between a valve seat 23 provided in the center of the inner cylinder 4 and between the two intermediate part walls 9 and the valve element storage space 6. Further, a drive device 24 for moving the valve rod 21 in the opening / closing direction of the valve body 22 is provided at the end of the valve body housing section 7,
The valve stem 21 is linked to a driving device 24 via a driving shaft 25.

The operation of the above configuration will be described below.
When a high-temperature fluid flows in the valve box flow path 3, a difference in thermal expansion or contraction between the inner cylinder 4 and the outer cylinder 2 occurs due to changes in the fluid temperature and the heat transfer coefficient of the fluid. Even when a difference in thermal expansion occurs between the upstream side and the downstream side of the outer cylinder 2, the spring 11 bends and absorbs the difference in thermal expansion or contraction, so that it is possible to prevent the valve box 1 from being unduly strained. Therefore, stable sealing and operability can be maintained.

Further, since the first packing 13 has a low thermal conductivity, it is difficult for the heat of the inner cylinder 4 to be transferred to the spring 11, and the second packing
Since the packing 15 has high thermal conductivity, the heat of the spring 11 is released to the outer cylinder 2 through the second packing 15. From this,
Even if a hot fluid flows, the temperature of the spring 11 will drop relatively,
Further, the first heat insulating material 19 and the second heat insulating material 20 are provided around the spring 11.
Since the and are provided, the spring 11 is not directly exposed to the high temperature fluid, and thus the temperature of the spring 11 can be further reduced. As a result, the design temperature of the spring 11 can be lowered, which facilitates the selection of materials and simplifies the design.

A first heat insulating material is provided between the outer cylinder 2 and the inner cylinder 4.
Since the 19 and the second heat insulating material 20 are enclosed, the temperature of the outer cylinder 2 can be lower than that of the inner cylinder 4. As a result, the design temperature of the outer cylinder 2 can be lowered, so that the design is simplified.

In the above embodiment, the sluice valve 26 for opening and closing the valve body 22 by using the drive device 24 (electrically driven, hydraulically driven or pneumatically driven) has been described, but a manually operated sluice valve may be used. . Although glass wool is used as the first heat insulating material 19 and the second heat insulating material 20 in the above embodiment, an air layer or castable refractory material may be used.

In the above embodiment, the connecting portion of the valve box 1 is of the flange 5 type, but it may be of butt welding type or insertion welding type. In the above embodiment, the two springs 11 are the valve bodies 22.
Although it is distributed to both front and rear sides with respect to the center, one spring 11 may be provided only on one of the front and rear sides.

[0024]

As described above, according to the first aspect of the present invention, a difference in thermal expansion or contraction between the inner cylinder and the outer cylinder of the valve box occurs due to changes in the fluid temperature and the heat transfer coefficient of the fluid. Alternatively, even when a difference in thermal expansion occurs between the upstream side and the downstream side of the valve box, the elastic body bends and absorbs the difference in thermal expansion or contraction, so that it is possible to prevent the valve box from being unduly strained. Therefore, stable sealing and operability can be maintained.

According to the second aspect of the present invention, since the first packing having a low thermal conductivity is provided at the contact portion between the elastic body and the inner cylinder, the heat of the inner cylinder is hard to be transferred to the elastic body. Further, since the second packing having high thermal conductivity is provided at the contact portion between the elastic body and the outer cylinder, the heat of the elastic body is released to the outer cylinder through the second packing. Therefore, even if the high-temperature fluid flows, the temperature of the elastic body is relatively lowered, and therefore the design temperature of the elastic body can be lowered, so that the material can be easily selected and the design is simplified.

[Brief description of drawings]

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

FIG. 2 is a detailed view of a connecting portion between an outer cylinder and an inner cylinder of a high temperature gate valve.

FIG. 3 is a partial sectional view of a conventional gate valve.

FIG. 4 is a sectional view of a conventional gate valve in which a valve element is divided.

FIG. 5 is a partially enlarged sectional view of a conventional sluice valve of a type in which a valve element is divided.

FIG. 6 is a partially enlarged sectional view of a conventional sluice valve of a type in which a notch is provided in a valve body.

[Explanation of symbols]

 1 Valve Box 2 Outer Tube 3 Valve Box Flow Path 4 Inner Tube 11 Spring (Elastic Body) 13 1st Packing 15 2nd Packing 26 High Temperature Gate Valve

Claims (2)

[Claims] 1. A valve box comprises an outer cylinder and an inner cylinder loosely fitted in the outer cylinder and having a valve box flow path, and the inner cylinder of the outer cylinder is provided between the outer cylinder and the inner cylinder. A high temperature sluice valve in which a ring-shaped elastic body connected to the peripheral portion and the outer peripheral portion of the inner cylinder is fitted, and a sealing material for sealing between the outer cylinder and the inner cylinder is provided. 2. The seal material is provided on the contact portion between the elastic body and the inner cylinder over the entire circumference, and the first packing having low thermal conductivity is provided on the contact portion between the elastic body and the outer cylinder over the entire circumference. The high temperature sluice valve according to claim 1, comprising a second packing having a high thermal conductivity.