JPH11141854A - Expansion joint of high temperature gas duct - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expansion joint which withstands the high temperatures exceeding 800 deg.C. SOLUTION: There are provided an inner duct 22 that delivers a high temperature gas, and an outer duct 23 that is fitted outside this inner duct 22 with a fixed interval to form a cooling passage 24 in the space with the inner duct 22. Movable flanges 31A and 31B that close the cooling passage 24 are mounted to the end surfaces of the inner ducts in the up and down stream sides 22a and 22b and the outer ducts in the up and down stream sides 23a and 23b, respectively, and a sliding sleeve 32 that is slidably fitted in the inner duct in the down stream side 22b is fixed to the inner duct in the upstream side 22a. Adjusting bolts and nuts 33A to 33E, which connect the movable flanges 31A and 31B in such a manner that they can freely approach to and separate from each other within a predetermined range, are provided. An expanding and contracting cover 35 having the elasticity to cover both movable flanges 31A and 31B is mounted to the outer peripheral part of the outer ducts 23a and 23b, and also a heat insulating material 36 having the properties of expansion and contraction is filled between the movable flanges 31A and 31B, and in the expanding and contracting cover 35.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an expansion joint of a high-temperature gas duct for absorbing expansion and contraction due to thermal expansion and contraction in a gas duct for sending a high-temperature exhaust gas of about 800.degree.

[0002]

2. Description of the Related Art In recent years, for example, in an incinerator, a melting furnace, a blast furnace, etc., the processing temperature has become higher, and the temperature of the discharged gas tends to increase.

Conventionally, joints for absorbing expansion and contraction of a pipe due to a temperature change include those shown in FIGS. FIG. 4 shows a bellows type made of metal. Sealing flanges 4 and 5 are attached to cylindrical bodies 2 and 3 having connecting flanges 1 and 1, respectively. The bellows 6 is connected, and a heat insulating material 7 is interposed in the bellows 6. Reference numeral 8 denotes an adjusting bolt for adjusting the expansion and contraction limit. 5 is a bellows type in which the joint portion is made of a non-metallic material, and the main body flanges 11 and 11 having the ribs 11a are connected to the bellows 12 by a telescopic heat insulating material 13, and a fixed heat insulating material 14 is provided inside the telescopic heat insulating material 13. Is provided with a baffle 15 having a built-in baffle.

[0004]

However, the working temperature of the above expansion joints is typically 600 ° C. or less, and when used for high-temperature exhaust gas of more than this, heat-resistant measures such as advanced materials and combined use of heat insulating materials are required. However, there is still a problem that 800 ° C. is the limit.

An object of the present invention is to provide an expansion joint for a high-temperature gas duct which can be used for a high-temperature gas at a temperature exceeding 800 ° C. and about 1000 ° C. .

[0006]

Means for Solving the Problems In order to achieve the above object, the invention according to claim 1 of the present invention comprises an inner duct through which high-temperature gas flows, and an inner duct which is fitted to the inner duct at a predetermined interval and is fitted inside. A water-cooled gas duct consisting of an outer duct that forms a cooling passage between the duct and the duct is provided, and a movable flange that closes the cooling passage over the end faces of the inner duct and the outer duct on the upstream and downstream sides is attached to each of the inner ducts. A connecting member for fixing a sliding sleeve slidably fitted in the other inner duct and connecting the two movable flanges to each other so as to approach and separate within a predetermined range is provided. An elastic expansion / contraction cover that covers the movable flange is attached, and a stretchable heat insulating material is filled between the movable flanges and inside the expansion / contraction cover.

[0007] According to the above configuration, the temperature of the inner duct and the outer duct are approximated by the cooling medium flowing through the cooling passage.
The contraction / expansion of the inner duct and the outer duct due to the temperature change is favorably absorbed by the sliding sleeve sliding on the inner surface of the other inner duct and the movable flange moving toward and away from the inner duct. Further, the sliding sleeve is effectively cooled through the inner duct and the movable flange which are brought into contact with the cooling medium, and local heating is prevented. Furthermore, the expansion and contraction cover that absorbs the displacement of the outer duct and the heat insulating material filled between the movable flange and the inside of the expansion and contraction cover prevent leakage of heat and high-temperature gas, and also prevent the heating of the expansion and contraction cover, The heat resistance of the joint is maintained.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an expansion joint for a high-temperature gas duct according to the present invention will be described with reference to FIGS.

The expansion joint 20 is, for example, 1000 ° C.
The ash melting furnace is interposed in the exhaust gas duct (gas duct) 21 of the ash melting furnace for reducing the volume and detoxifying the ash by melting the ash at a temperature exceeding the above. Good. The exhaust gas duct 21 is of a water-cooled type for sending exhaust gas of about 1000 ° C.

That is, the water-cooled exhaust gas duct 21 comprises a circular metal inner duct 22 for flowing the high-temperature exhaust gas G,
A circular metal outer duct 23 which is fitted to the inner duct 22 at a fixed interval and forms a cooling passage 24 with the inner duct 22 is formed. Water supply nozzle 2 for sending cooling water W as a cooling medium
5 and a drain nozzle 26 for discharging the cooling water W are provided. 27 is a connection flange.

The expansion joint 20 has movable flanges 31A and 31B projecting outward from both end surfaces of the upstream and downstream inner ducts 22a and 22b to end surfaces of the upstream and downstream outer ducts 23a and 23b, respectively. Since the cooling passage 24 is closed and separated by the movable flanges 31 </ b> A and 31 </ b> B, a water supply nozzle 25 and a drainage nozzle 26 are provided for each cooling passage 24.

A sliding sleeve 32 is fixed in the upstream inner duct 22a so that the downstream side is slidably fitted in the other downstream inner duct 22b. Movable flange 3
Bolt holes 31a are formed in the outer peripheral portions of 1A and 31B at regular intervals in the circumferential direction, and are adjustment tools which connect the movable flanges 31A and 31B between the bolt holes 31a and 31a in a predetermined range so as to approach and separate from each other. Bolts 33A and adjustment nuts 33B to 33E are mounted. The adjustment nuts 33B to 33E are fixed when the exhaust gas duct 21 is installed, but are loosened after the installation as long as the adjustment nut 33C allows thermal deformation as indicated by a virtual line.

Further, ring-shaped stopper plates 34A, 34A are provided on the outer peripheral portions of the upstream and downstream outer duct ducts 23a, 23b.
34B, a resilient expansion / contraction cover 35 that covers both movable flanges 31A, 31B is attached via the retaining plates 34A, 34B. This expansion / contraction cover 35
Are a pair of thin plate-shaped displacement absorbing plates 3 fixed to the stopper plates 34A and 34B and capable of permitting displacement by elasticity.
5a and 35b, and cover cylinders 35d and 35e which cover the entire outer periphery of the displacement absorbing plates 35a and 35b and are connected by a connecting portion 35c including a connecting flange and connecting bolts.

Further, the space between the movable flanges 31A and 31B and the inside of the expansion / contraction cover 35 are filled with a heat-insulating material 36 having elasticity. Bulk fiber)
Is used.

In the above configuration, the cooling water is supplied from the water supply nozzle 25 to the cooling passage 24, discharged from the drain nozzle 26 and circulated, and the exhaust gas of about 1000 ° C. is sent through the inner duct 22. Then, the inner duct 22 and the outer duct 23 are heated and cooled by the cooling water W, and settle down to about 100 ° C. as a whole. At this time, the temperature gradient in the radial direction is extremely small.

When the inner duct 22 and the outer duct 23 expand and expand due to the heat at this time, the sliding sleeve 32 moves along the inner surface of the downstream inner duct 32b, and the movable flanges 31A and 31B approach and expand. Is absorbed. Further, displacement of the outer duct 23 is absorbed by displacement of the displacement absorbing plates 35a and 35b of the expansion / contraction cover 35. The heat of the sliding sleeve 32 is transferred to the upstream and downstream inner ducts 22.
a, 22b and the movable flanges 31A, 31Ba are satisfactorily conducted and absorbed by the cooling water, and are not locally heated. Further, the heat insulating material 36 and the expansion / contraction cover 35 prevent the heat and exhaust gas of the sliding sleeve 32 and the movable flanges 31A and 31B from leaking outside, and also protect the expansion / contraction cover 35 from heat.

According to the above-described embodiment, the sliding sleeve 32 is provided on the upstream inner duct 22a so that the downstream inner duct 22a is provided.
b, and the heat of the sliding sleeve 32 is transferred to the upstream and downstream inner ducts 22a, 22b and the movable flange 31.
A configuration is adopted in which the cooling water in the cooling passage 24 is absorbed through the A and 31B, so that the expansion of the inner duct 22 and the outer duct 23 can be reliably absorbed and local heating can be eliminated. . Movable flange 31
A heat insulating material 36 is provided in the space between A and 31B and in the expansion / contraction cover 35.
, The leakage of exhaust gas and heat can be effectively prevented, and the heating of the expansion / contraction cover 35 is also prevented.

[0018]

As described above, according to the first aspect of the present invention, the temperature of the inner duct and the outer duct are approximated by the cooling medium flowing through the cooling passage, and the temperature of the inner duct and the outer duct is changed by the temperature change. The contraction / expansion is well absorbed by the sliding sleeve sliding on the inner surface of the other inner duct and the movable flange moving closer to or away from the inner duct. Further, the sliding sleeve is effectively cooled through the inner duct and the movable flange which are brought into contact with the cooling medium, and local heating is prevented.
Furthermore, the expansion and contraction cover that absorbs the displacement of the outer duct and the heat insulating material filled between the movable flange and the inside of the expansion and contraction cover prevent leakage of heat and high-temperature gas, and also prevent the heating of the expansion and contraction cover, The heat resistance of the joint is maintained.

[Brief description of the drawings]

FIG. 1 shows an embodiment of an expansion joint according to the present invention and is an enlarged longitudinal sectional view of a main part of the expansion joint.

FIG. 2 is an overall vertical sectional view of the expansion joint.

FIG. 3 is a sectional view taken along the line ii shown in FIG. 2;

FIG. 4 is a partial longitudinal sectional view showing a conventional expansion joint.

FIG. 5 is a partial longitudinal sectional view showing another conventional expansion joint.

[Explanation of symbols]

 Reference Signs List 20 expansion joint 21 water-cooled exhaust gas duct 22 inner duct 22a upstream inner duct 22b downstream inner duct 23 outer duct 23a upstream outer duct 23b downstream outer duct 24 cooling passage 25 water supply nozzle 26 drainage nozzle 31A, 31B movable flange 32 sliding Moving sleeve 33A Adjusting bolt (connecting tool) 33B-33E Adjusting nut (connecting tool) 35 Expansion / contraction cover 35a, 35b Displacement absorbing plate 36 Thermal insulation

Continued on the front page (72) Inventor Tsuneharu Sakakibara 5-3-28 Nishikujo, Konohana-ku, Osaka, Osaka Inside Hitachi Zosen Corporation (72) Inventor Motohiro Yamaue 5-3-1 Nishikujo, Konohana-ku, Osaka-shi, Osaka 28 Inside Hitachi Zosen Corporation (72) Inventor Hideo Sato 5-28 Nishikujo, Konohana-ku, Osaka City, Osaka Inside Hitachi Zosen Corporation

Claims (1)

[Claims] 1. A water-cooled gas duct comprising an inner duct for flowing high-temperature gas and an outer duct which is fitted to the inner duct at a predetermined interval and forms a cooling passage between the inner duct and an inner duct. And a movable flange for closing the cooling passage over the end surfaces of the inner duct and the outer duct on the downstream side, and a sliding sleeve slidably fitted in the other inner duct is fixed to one inner duct, and A connecting tool for connecting the two movable flanges to each other in a predetermined range so as to be able to approach and separate from each other is provided.A flexible elastic cover for covering both the movable flanges is attached to the outer peripheral portions of the outer ducts. An expansion joint for a high-temperature gas duct, which is filled with an insulating material having elasticity.