JPS6124589B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention forms a flow path for passing purge fluid toward the inside of the valve body between a valve stem and a cylindrical part on the valve body side through which it passes, and The present invention relates to a butterfly valve provided with a gland packing part for preventing leakage from a flow path to the outside.

This type of butterfly valve is suitable for application to fluid transport paths that are exposed to high temperatures, high pressures, and contain dust, such as combustion exhaust gas, but there is a problem of seizure due to the transport fluid, and conventionally, the valve stem A bearing portion for the ground is provided outside the gland packing portion. However, the distance between both bearings is long,
When fully closed, the valve stem bends significantly due to the fluid pressure applied to the valve body, resulting in a seal failure, and in order to prevent dust from entering, it is necessary to increase the amount of purge fluid supplied into the valve body. As a result, the flow rate of the purge fluid between the cylindrical portion of the valve body and the valve stem becomes high, resulting in a problem that the stem and the cylindrical portion of the valve body are eroded. Therefore, it has been considered to make the valve stem larger in diameter to reduce the deflection, but this has the disadvantage of reducing the flow path opening area when fully open and deteriorating the flow characteristics.

In view of the above points, the present invention suppresses bending deformation caused by fluid pressure without increasing the diameter of the valve stem while avoiding seizure of the bearing part, and provides sealing and sealing for the gland packing part. The purpose is to provide good protection from dust.

In the butterfly valve of the present invention, a flow path for passing purge fluid toward the inside of the valve body is formed between the valve stem and the cylindrical portion on the valve body side through which it passes, and a flow path for passing the purge fluid toward the inside of the valve body is formed. The butterfly valve is provided with a gland packing part for preventing leakage to the outside, and is divided in the hand direction, and between the divided gland packing parts, a flat bearing is attached to the valve stem and the valve body side cylinder. A characteristic feature of the present invention is that a path is formed for fitting into the shaped portion and supplying grease to a sliding contact portion of the plain bearing with respect to the valve stem and the valve body side cylindrical portion.

Therefore, the following effects can be obtained.

○B Each gland packing part has a flat bearing that can be fitted into a gap that is generally very narrow compared to other bearing members, such as between the valve stem and the cylindrical part on the valve body side. By fitting the valve stem between the two, the valve stem can be supported closer to the valve body, and the distance between the bearing and the valve stem can be reduced, without increasing the diameter of the valve stem. The amount of bending deformation of the valve stem caused by the fluid pressure applied to the valve body can be reduced, and the sealing when fully closed can be performed well, and the flow characteristics can be improved.

○B By forming a path for supplying grease to the sliding contact points between the valve stem and the valve body side cylindrical part of the plain bearing, seizing of the valve stem and the plain bearing can be prevented, and the gland packing part can be prevented from seizing. Improves sealing performance.

Next, embodiments of the present invention will be described in detail based on the drawings.

A hollow cylindrical valve stem 1 is freely rotatable via bearing parts 4, 4 with its both ends inserted into valve body side cylindrical parts 3, 3 formed in a valve body 2, respectively. A valve opening/closing mechanism 5 is movably connected to one end of the valve stem 1, and as the valve body 6 rotates, a seat 7 attached to the circumferential surface of the valve body 6 is moved to the inner circumferential surface of the valve body 2. It is configured to be in close contact with and spaced apart from a seat 8 provided in Gland packing parts 9, 9 are provided, and a flow path _R1 for passing a purge fluid such as steam is formed further on the valve body 6 side. The butterfly valve is suitable for use in a transportation route for gases containing dust at high temperature and high pressure, such as exhaust gas generated during the regeneration of silica sand (SiO ₂ ) and the like.

The gland packing parts 9, 9 are each divided in the longitudinal direction of the valve stem 1, and
A flat bearing 10 is fitted between each of the divided gland packing parts 9a and 9b, and the valve stem 1 is placed between the two bearing parts 4, 4 and the two flat bearings 10, 10 with respect to the valve body 2.
It is configured to be supported at a point.

Fillings 11, such as stellite, are welded to the portions of the plain bearings 10, 10 that come into sliding contact with the valve stem 1, and the portions of the valve body 1 corresponding to the plain bearings 10, 10, respectively.
11 is provided, and a grease supply path R ₂ is communicated and connected through the valve box side cylindrical portion 3.
An annular groove 1 formed on the inner and outer peripheral surfaces of the plain bearing 10
2, 13 and both grooves 12, 13 are connected to each other through through holes 14 bored at four locations in the circumferential direction. and the valve stem 1 and plain bearings 10, 10
This structure is designed to prevent seizure of the respective parts and to improve the sealing performance of the gland packing parts 9, 9.

In order to supply the purge fluid, annular grooves 15 and 16 are formed on the inner and outer circumferential surfaces, respectively, and through holes 1 communicate with the grooves 15 and 16 at six locations in the circumferential direction.
A purge ring 18 with holes 7... is provided between the valve box side cylindrical part 3 and the valve stem 1, and is connected to the outer circumferential groove 16 and the flow path.
A flow path formed by a gap between the valve stem ₁ and the collar 19 provided to surround it, and the bushing 20 fitted inside to surround the valve box side cylindrical part 3. The purge fluid is supplied into the valve box 2 through R to prevent dust from entering into the gland packing part 9 and the plain bearing 10 side, and to provide heat insulation from the transportation fluid.

Inside the valve stem 1, one end thereof is provided with an inlet 21.
In addition, the other end is configured as an outlet 22 to allow cooling air to flow, and is configured to cool the valve stem 1.

Note that the present invention is not limited to supporting the valve stem 1 at four points as in the above-mentioned embodiment, but is applicable to supporting the valve stem 1 at both flat bearings 1.
It may be supported at two points of only 0 and 10.

[Brief explanation of the drawing]

The drawings show an embodiment of the butterfly valve according to the present invention, with FIG. 1 being a partially cutaway view and FIG. 2 being an enlarged longitudinal sectional view of the main part. DESCRIPTION OF SYMBOLS 1... Valve stem, 2... Valve box, 3... Valve box side cylindrical part, 4... Bearing part, 9... Gland packing part, 9a, 9b... Divided gland packing part,
10...Flat bearing, 11...Filling metal, _R1 ...Flow path,
R ₂ ...Grease supply route.

Claims (1)

[Claims] 1 Valve stem 1 and valve body side cylindrical part 3 for passing through it,
3, a flow path _R1 for passing the purge fluid toward the inside of the valve box 2 is formed, and the flow path _R1
The butterfly valve is provided with a gland packing part 9 for preventing leakage to the outside, and the gland packing part 9 is divided in the longitudinal direction of the valve stem 1, and the divided gland packing Between the parts 9a and 9b, the plain bearing 1
0 into the valve stem 1 and the valve box side cylindrical part 3, and a route for supplying grease to the sliding contact points of the flat bearing 10 with the valve stem 1 and the valve box side cylindrical part 3.
Butterfly valve formed with R ₂ .