JP2977008B2 - Valve stem cooling structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve stem cooling structure for controlling a high-temperature fluid.

[0002]

2. Description of the Related Art As a conventional valve stem cooling structure used for controlling a high-temperature fluid, there is, for example, one shown in FIG. In FIG. 4, a valve body 4 that rotates around the axis of a valve rod 3 is disposed inside a valve box 2 of the butterfly valve 1, and the valve body 4 is a valve body boss 4 a for inserting the valve rod 3. And a valve body plate 4b for opening and closing the flow path in the valve box.
A pair of left and right valve box bosses 5 provided on both sides of the valve box 2 rotatably support the valve rod 3 via bearings 6, respectively. The valve rod 3 forms a hollow shaft and the hollow portion 7 is a cooling fluid. A flow path of (e.g., air, steam, or water) 8 is formed, and one opening of the hollow portion 7 forms an inlet 7 a for the cooling fluid 8, and the other opening forms an outlet 7 b of the cooling fluid 8. .

In this configuration, the cooling fluid 8 flowing into the hollow portion 7 from the inlet 7a cools the valve rod 3 and then flows out of the system from the outlet 7b.

[0004]

However, in the above configuration, the difference between the temperature of the cooling fluid 8 at the inlet 7a and the temperature of the cooling fluid 8 at the outlet 7b is extremely large, and the difference between the temperature of the valve rod 3 and the temperature is extremely large. A sufficient cooling effect could not be provided. Further, the temperature of the valve stem 3 on the side of the discharge port 7b increases, and the corresponding bearing 6 is heated.
However, there is a problem that the wear progresses quickly, and the strength of both the valve rod and the bearing is weakened to shorten the life. further,
If an attempt is made to increase the amount of the cooling fluid in order to enhance the cooling effect, there has been a problem that the size of the cooling equipment for adjusting the cooling fluid to a predetermined temperature and the equipment for generating the fluid are increased, and the running cost is increased.

The present invention solves the above-mentioned problems, and
It is an object of the present invention to provide a valve stem cooling structure for a valve which can perform efficient cooling with a small amount of cooling fluid, prevent the temperature of the valve stem from rising, and prevent the bearing from being heated.

[0006]

In order to solve the above-mentioned problems, a valve stem cooling structure of a valve according to the present invention is configured such that a valve element supported by a valve stem in a valve box is rotatable around the axis of the valve stem. In a valve which is rotatably supported by a valve box boss via bearings on both sides of a valve stem, a valve stem passing through the valve body boss of the valve body is formed by a hollow shaft, and the hollow portion of the valve stem is formed. Is used as a cooling fluid flow path, and a plurality of voids having a large opening area are provided on the inner peripheral surface of the valve body boss that contacts the outer peripheral surface of the valve rod.

[0007] Further, a heat insulating material is attached to the gap.

[0008]

According to the above construction, the heat received by the valve body from the fluid to be controlled is transmitted from the valve body boss to the valve stem. At this time, since the inner peripheral surface of the valve body boss has a plurality of voids that are opened facing the outer peripheral surface of the valve stem, the inner peripheral surface of the valve body boss that contacts the outer peripheral surface of the valve stem is present. The area, that is, the heat transfer area is reduced, and the amount of heat transmitted to the valve stem is reduced. For this reason, the valve stem can be maintained at a predetermined temperature even with a small amount of cooling fluid, and it is possible to prevent the valve stem from increasing in temperature and prevent the bearing from being heated.

Further, even when a heat insulating material is attached to the gap, the amount of heat transmitted to the valve stem can be similarly reduced, and the amount of cooling fluid can be reduced.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. Members that perform the same operations as those described above with reference to FIG. 4 are denoted by the same reference numerals, and description thereof is omitted.

In FIG. 1 and FIG. 2, the valve stem 3 forms a hollow shaft, and the hollow portion 7 forms a cooling fluid flow path 11. Valve stem 3
Penetrates through the valve body boss 4 a of the valve body 4, and has a plurality of voids 12 having a large opening area on the inner peripheral surface of the valve body boss 4 a contacting the outer peripheral surface of the valve rod 3. It is formed long along the direction of the center. A heat insulating material 13 made of a member having a small thermal conductivity is attached to each of the gaps 12. The heat insulating material 13 is attached as needed, and it is also possible to adopt a configuration in which no member is present in the gap portion 12.

The shape of the gap 12 is not limited to that of the present embodiment, and as shown in FIG.
May be provided at appropriate intervals along the axial direction of the valve stem 3.

The operation of the above configuration will be described below. The heat received by the valve body 4 from the controlled fluid is generated by the valve body boss 4a.
From the valve stem 3. At this time, a plurality of gaps 1 opening on the inner peripheral surface of the valve body boss 4a so as to face the outer peripheral surface of the valve rod 3 are provided.
2, the area of the inner peripheral surface of the valve body boss 4a that comes into contact with the outer peripheral surface of the valve stem 3, that is, the heat transfer area becomes smaller when the heat insulating material 13 does not exist in the gap portion 12. The amount of heat transmitted to the valve stem 3 decreases. For this reason, the valve stem 3 can be maintained at a predetermined temperature even with a small amount of cooling fluid, and the temperature of the valve stem 3 is prevented from increasing, thereby preventing the bearing 6 from being heated.
The life of the bearing can be extended.

Further, even when the heat insulating material 13 is attached to the gap portion 12, it is natural that the amount of heat transmitted to the valve stem 3 can be similarly reduced to reduce the amount of the cooling fluid.

[0015]

As described above, according to the present invention, by reducing the contact area between the valve stem and the valve body boss, the amount of heat transmitted to the valve stem is reduced, and the valve stem can be reduced even with a small amount of cooling fluid. The temperature can be maintained at a predetermined temperature, and the temperature of the valve stem can be prevented from increasing, thereby preventing the bearing from being heated. As a result, less power is required to prepare the cooling fluid, and running costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing a valve stem cooling structure of a valve according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a sectional view of a main part showing a valve stem cooling structure of a valve according to another embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a valve stem cooling structure of a conventional valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 3 Valve stem 7 Hollow part 11 Cooling fluid flow path 12 Void part 13 Thermal insulation

Claims (2)

(57) [Claims] 1. A valve body which is rotatably supported by a valve rod in a valve box is rotatably disposed around the axis of the valve rod, and both sides of the valve rod are rotatably supported by a valve box boss via bearings. In the valve, the valve stem passing through the valve body boss of the valve body is formed by a hollow shaft, and the hollow portion of the valve stem forms a cooling fluid flow path, and the inner peripheral surface of the valve body boss abuts on the outer peripheral surface of the valve stem. A valve stem cooling structure for a valve, wherein a plurality of voids having a large opening area are provided in the valve stem. 2. The valve stem cooling structure for a valve according to claim 1, wherein a heat insulating material is attached to the gap.