JPH0320628B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a high-temperature fluid flow rate control valve, and more specifically, a valve used for controlling the flow rate of high-temperature, high-pressure air blown into a blast furnace from a tuyere of a blast furnace. The present invention relates to a particularly effective flow control valve.

[Conventional technology]

As is well known, the tuyeres of blast furnaces e.g.
High-pressure, high-temperature air (hereinafter referred to as hot air) at 1300℃ and 3.5Kg/cm ² (gauge pressure) is blown at a high flow rate of 200m/sec or more. 30 to 50 such tuyeres are provided around the outer periphery of the blast furnace, and it is necessary to change the amount of hot air blown into the blast furnace from the tuyeres depending on the operational status of the blast furnace. For this reason, recently it has become possible to control the flow rate independently for each tuyere. In other words, even though the air flow rate is constant, the production volume increases and the furnace heat decreases due to changes in the reaction inside the furnace, or the extraction of hot metal and slag is insufficient because the tapping operation does not proceed smoothly. If it becomes dry, increase or decrease the air flow as necessary.
In addition, during the period of increased production, the amount of air blown will be increased to the extent that reactions in the furnace, especially countercurrent reactions, allow. As described above, as blast furnace operating methods become more sophisticated, opportunities to adjust the amount of hot air blown from the tuyere are increasing, and for this reason, control valves that adjust the amount of air blown have a wide adjustment range. It is requested.

By the way, attempts have been made to use control valves made of metal valve bodies as flow rate control valves for tuyeres, but since the valve body lacks heat resistance and cannot withstand high temperatures, the valve body has been water-cooled. This was also attempted, but the heat loss was large and it was not put to practical use. For this reason, a butterfly valve has been proposed in which the valve plate and valve stem of the valve body are integrally constructed of ceramics, and the valve body is housed in a casing lined with a heat-resistant material to form a flow path. There is (Jitsugan 1982-)
(See No. 170080).

[Problem that the invention seeks to solve]

The valve body made of ceramics as described above has high heat resistance and poses no practical problem in this respect, but since the valve plate that opens and closes the flow path is cantilevered, it not only has strength problems, but also It was difficult to form a uniform gap around the entire circumference between the outer circumference and the inner wall of the flow path, so the gap between them had to be made larger (in a flow path with an inner diameter of 200 mm, the valve The outside diameter of the plate is 170mm, so the gap is about 15mm). For this reason, even if the valve plate is fully closed, hot air is sent through the above gap, so the flow rate cannot be significantly restricted (flow rate Q when the valve plate is fully open and flow rate Q when it is fully closed _). (the ratio Q ₁ /Q is 50% or more), it was impossible to control the flow rate over a wide range.

[Means for solving problems]

The present invention has been made in order to solve the above problems, and includes a valve body formed by integrally forming a valve plate, a valve shaft and a support shaft provided above and below the valve plate with ceramics, and a flow path and a support shaft. It has a pair of annular support members made of ceramics having the same inner diameter and formed to rotatably support the lower part of the valve body, and the support members are connected to the valve plate, the base of the valve shaft, and the support shaft. It is connected from both sides and placed inside the casing.

[Effect]

Since the valve body is supported at the top and bottom of the valve plate by the valve shaft and support shaft, it is not only strong but also
It is possible to rotate accurately within the flow path, and the gap between the support member and the valve plate can be made extremely small.

〔Example〕

FIG. 1 is a front view of an embodiment of the present invention, partially shown in cross section, and FIG. 2 is a side view thereof, partially shown in cross section. In both figures, 1 is a control valve according to the present invention, 2 is a valve body, 3 is a casing that accommodates the valve body,
5 is a driving section for the valve body 2.

In the valve body 2, 21 is a disc-shaped valve plate, 22 is a valve shaft provided on the upper part of the valve plate 21, and 23 is a support shaft provided on the same line as the valve shaft 22 at the lower part of the valve plate 21, and these are made of ceramics. It is integrally constituted by.

In the casing 3, 31 is a steel outer cylinder having flanges 32, 32a and 33 at both ends and the upper part, and 34, 34a are cylindrical first heat-resistant members whose outer diameter matches the inner diameter of the outer cylinder 31. , semicircular cutout portions 35, 35 into which the valve stem 22 is inserted.
a is formed. 36, 36a has the first outer diameter
A cylindrical second heat resistant member that matches the inner diameter of the heat resistant members 34, 34a and is longer than the first heat resistant members 34, 34a, 37 is a hot air flow path, and 38, 38a are cutouts provided on the inner periphery of the opposing part. 39, 39a are semicircular cutouts provided at the upper part of the cutouts 38, 38a, into which the valve shaft 22 is inserted; 40, 40a are the ends of the first heat-resistant members 34, 34a on the outer periphery of the ends; This is the stepped part that has been removed up to the point. Reference numerals 41 and 41a are ring-shaped support members made of ceramics, and the outer diameter thereof is the same as the cutout portions 38 and 38 of the second heat-resistant members 36 and 36a.
a, and the inner diameter is the second heat insulating member 36, 36a.
It is formed to match the inner diameter of the flow path 37, and thus the diameter of the flow path 37. 42 and 42a are bushes. 43, 43a are ring-shaped holding members made of heat-resistant material, the outer diameter of which matches the inner diameter of the outer cylinder 31;
The inner diameter is the step portion 40 of the second heat-resistant member 36, 36a,
40a, and an L-shaped cutout 44 at the end.
44a is formed. 45, 45a are ring-shaped fasteners, and 46, 46a are gland packings.

The flow control valve consisting of the above-mentioned parts includes bushes 42 and 4 on the valve shaft 22 and support shaft 23 of the valve body 2.
Support members 41 and 41a are coupled from both sides via 2a and accommodated in outer cylinder 31, with valve shaft 22 protruding upward. In this state, the second heat-resistant members 36, 36
A is inserted from both sides, and the supporting members 41 and 41a are fitted to the cutout portions 38 and 38a, and the semicircular cutout portions 39 and 39a are fitted to the valve shaft 22. Next, the first heat-resistant members 34, 34a are inserted into the outer periphery from both sides, the semicircular cutouts 35, 35a are fitted to the valve shaft 22, and the steps of the second heat-insulating members 36, 36a are inserted between the two sides and the second heat-resistant members 36, 36a. The holding members 43, 43a are fitted into the parts 40, 40a.

Next, a gland packing 46,
Fasteners 45, 45a are fitted through 46a, and these fasteners 45, 45a are welded to the inner wall of the outer cylinder 31 to join them together. Finally, the control valve 1 is completed by connecting the valve shaft 22 and the output shaft of the motor 51 and fixing the cover 52 to the flange 33.

In the above embodiment, the second heat resistant members 36, 36
Since the diameter of the flow path 37 formed by the support members 41 and 41a is 200 mm, and the outer diameter of the valve plate 21 of the valve body 2 is 198 mm, there is a gap between the inner wall of the flow path 37 and the outer periphery of the valve plate 21. An extremely small gap (1 mm) could be formed.

In the flow control valve of the present invention configured as described above, the control valve 1 is connected to the air blowing pipe of the tuyere through the flanges 32, 32a, and the motor 51 of the drive unit 5
If the valve stem 22 is rotated by the
2 and support shaft 23 as axes, and the flow rate of hot air flowing through the flow path 37 can be adjusted over a wide range.

In the above embodiment, the control valve according to the present invention is used to control the flow rate of hot air blown into the blast furnace tuyere, but it goes without saying that it can also be used to control other high-temperature fluids. Nor.

〔Effect of the invention〕

As is clear from the above description, in the present invention, a valve body consisting of a valve plate, a valve stem, and a support shaft is integrally constructed of ceramics, and the lower part is supported by a support member made of ceramics. Not only is it strong because it is supported at two points, but
The fluid flow path can be opened and closed accurately, and the gap between the inner wall of the support member and the valve body can be made as small as possible. According to the example, when the diameter of the fluid flow path (therefore, the inner diameter of the support member) is 200 mm and the outer diameter of the valve plate is 198 mm (therefore, the gap between the two is 1 mm), when the valve plate is fully opened, If the flow rate is Q and the flow rate when fully closed is Q ₁ , the ratio between the two, Q ₁ /Q, is approximately 5% to 100% as shown in Figure 3A, making it possible to adjust the flow rate over a very wide range. did it. In addition, the third
B in the figure shows Q ₁ /Q when the above gap is 5.2 mm,
C shows Q ₁ /Q when the gap is 15 mm, which shows that the effect of the present invention is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of the present invention partially shown in cross section, FIG. 2 is a side view thereof partially shown in cross section,
FIG. 3 is a diagram showing the relationship between the gap between the flow path and the valve plate and the flow rate. 1: Control valve, 2: Valve body, 3: Casing, 5:
Valve body drive unit, 21: Valve plate, 22: Valve shaft, 23:
Support shaft, 31: Outer cylinder, 34, 34a, 36, 36
a: Heat resistant member, 37: Channel, 41, 41a: Support member, 42, 42a: Bush, 43, 43a:
Holding member, 45, 45a: stopper.

Claims (1)

[Scope of Claims] 1. A control valve comprising a valve body rotatably disposed in a casing in which a flow path is formed by a heat-resistant member, comprising: a valve plate and a valve shaft and support provided above and below the valve plate; a valve body whose shaft is integrally formed of ceramic; and a pair of annular supports made of ceramic having an inner diameter approximately equal to the flow path and formed to rotatably support a lower portion of the valve body. A flow rate control valve for high-temperature fluid, comprising: a support member connected from both sides of the valve plate, the base of the valve shaft, and the support shaft and disposed within the casing.