JPH0624271U - Butterfly valve for hot gas pipeline - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the heat insulation of butterfly valves for hot gas pipelines. [Structure] A valve box valve seat 31 composed of two bearing portions 33 having a shaft hole for inserting the valve shaft 2 and a ring 34 connecting the bearing portions is provided on the entire circumference in the center of the inner peripheral wall 11 of the valve box 1. Secure across. Insulating material 4 closely adhered to both upstream and downstream sides of the valve box seat
Is lined on the entire inner wall. The heat-resistant metal plate 5 is coated on the inner peripheral surface of the heat insulating material. [Effect] Since the discontinuous portion of the valve box valve seat, which was interrupted at the portion where the valve shaft is inserted, is eliminated and gas leakage inside the valve is prevented, there is no risk of deterioration or damage to the valve function.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a butterfly valve used in a high temperature gas pipeline connected to a gas turbine or a blast furnace.

[0002]

[Prior art]

 Conventionally, a butterfly valve for high temperature gas has a flow passage formed on the inner peripheral wall so that the retained heat of the gas passing through the valve is not lost and the valve box itself is not deformed or corroded due to high heat. As shown in FIGS. 4 and 5, the heat insulating material is lined in the shape of a semicircular arc, avoiding the portion where the valve shaft 2a is inserted through the central portion of the inner peripheral wall 11a of the valve casing 1a. The valve seat 31a is fixed, and the heat insulating material 4a is lined on both sides of the valve box valve seat to form the flow path 6a.

[0003]

[Problems to be solved by the device]

 By the way, in the case of this prior art, since the semicircular arcuate valve seat valve seat 31a is fixed while avoiding the portion where the valve shaft 2a is inserted into the central portion of the inner peripheral wall 11a of the valve housing, the valve shaft is inserted. The valve box valve seat is interrupted at a point, and when the valve is closed and the differential pressure between the upstream side and the downstream side of the valve becomes large, this interrupted portion forms a kind of passage S. That is, the passage S communicates with the gap at the joint between the valve box inner peripheral wall 11a existing on the upstream side and the downstream side of the valve box valve seat 31a and the heat insulating material 4a, and the gap inside the heat insulating material, and the high temperature gas communicates with them. Leakage occurs inside the valve through the gap. Moreover, as the leak continues, the gap is gradually expanded by the flow pressure and the amount of leak increases, causing the valve box itself to be heated to a high temperature and in a dangerous state. There is a problem in that there is a risk of cracks and breakage.

In order to solve the above-mentioned problems, the present invention aims to provide a butterfly valve for a high temperature gas pipeline, which prevents high temperature gas from leaking inside the valve box and causing deterioration or damage of the valve function. And

[0005]

[Means for Solving the Problems]

 A butterfly valve for a hot gas line according to the present invention comprises two bearing portions 33 having a shaft hole 32 for inserting a valve shaft 2 in a central portion of an inner peripheral wall 11 of a valve box 1 and a ring connecting the bearing portions 33. The valve box valve seat 31 made of 34 is fixed over the entire circumference, and the inner surface of the inner wall 11 is lined with the heat insulating material 4 in close contact with both sides of the valve box valve seat 31, and the surface of the heat insulating material 4 is heat-resistant. The above problem was solved by coating with the metal plate 5.

[0006]

[Action]

 There are two bearings that insert the valve shaft into the center of the inner wall of the valve box. Since the bearings are connected by a ring, there is no interruption in the insertion position of the valve shaft, and the heat insulation is tightly attached to both sides. Since the entire inner peripheral wall is covered with a material, there is no communication between the gap between the inner wall of the valve box and the heat insulating material existing on the upstream and downstream sides of the valve box valve seat and the gap formed in the heat insulating material itself. Disappear.

[0007]

【Example】

 1 is a vertical sectional front view of an embodiment of the present invention, FIG. 2 is a vertical sectional side view, and FIG. 3 is a perspective view showing a state where the valve box and the valve box valve seat of the same embodiment are mounted. In each figure, a valve shaft 2 is rotatably inserted into and rotatably supported in a cylindrical valve housing 1, and a disc-shaped valve element 3 is fixed to the valve shaft 2 by a pin 35. A valve box valve seat 31 is fixed at the center of the inner peripheral wall 11 of the valve box at right angles to the flow path 6, and when the valve is closed, the valve body 3 is in close contact with the ring 34, which is connected by this ring. The bearing portion 33 has a shaft hole 32 through which the valve shaft 2 is inserted.

The heat insulating material 4 is lined over the entire circumference of the valve box inner peripheral wall 11 with the valve box valve seat 31 sandwiched from the upstream side and the downstream side. That is, the heat insulating material is also in close contact with the bearing portion 33 and filled without any gap. Further, the inner peripheral surface of the heat insulating material 4 is covered with a heat resistant metal plate 5 to directly cut the contact between the high temperature gas in the flow path and the heat insulating material. In the figure, the valve box is provided with a packing 21 and a packing retainer 22 in the valve box penetrating portion of the valve shaft 2 to keep the valve box airtight.

[0009]

[Effect of device]

 As described above, according to the present invention, communication between the gap between the heat insulating material and the inner peripheral wall 11 of the valve housing on the upstream side and the downstream side of the valve housing and the clearance inside the heat insulating material is prevented, Leakage inside the valve is prevented. As a result, there is no problem that the outer skin of the valve box body has been heated to high temperature and is in a dangerous state, and cracks in the heat insulation material break the heat insulation material and cause it to fall out of the valve. It was Furthermore, since the heat-insulating metal plate protects the inner surface of the heat-insulating material, the surface of the heat-insulating material can be prevented from being damaged or washed away by contact with the high-speed fluid when the valve is opened.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of an embodiment of the present invention.

FIG. 2 is a vertical side view of the same embodiment.

FIG. 3 is a partial perspective view showing a mounted state of a valve box and a valve box valve seat of the same embodiment.

FIG. 4 is a vertical sectional front view of a conventional technique.

FIG. 5 is a vertical side view of the same prior art.

[Explanation of symbols]

 1 valve box 2 valve shaft 3 valve body 4 heat insulating material 5 heat resistant metal plate 6 flow path 11 inner peripheral wall 31 valve box valve seat 32 shaft hole 33 bearing portion 34 ring

Claims (1)

[Scope of utility model registration request] 1. A butterfly valve for a high-temperature gas pipeline, comprising a valve box 1 having a valve body 1 having a heat insulating material 4 forming a flow passage formed on an inner peripheral wall thereof, and a valve shaft 2 having a valve body 3 rotatably supported therein. Two bearing parts 33 having a shaft hole 32 for inserting the valve shaft 2 in the central part of the inner peripheral wall 11 of the box 1 and a ring 3 connecting the bearing parts 33.
A valve box valve seat 31 composed of 4 is fixed over the entire circumference, and is closely adhered to both sides of the valve box valve seat 31, and a heat insulating material 4 is lined on the entire inner peripheral wall 11, and the surface of the heat insulating material 4 is made of a heat-resistant metal. A butterfly valve for a high-temperature gas pipeline, which is covered with a plate 5.