JPH08128574A - Gas distribution pipe connection device - Google Patents

Abstract

(57) [Summary] [Purpose] Welding work of bellows is done in a short time, and installation work of the pressurized fluidized bed boiler and turbine is done in a short time.
Improve the operating efficiency of the boiler. Structure: Gas flow through flanges 17 and 18 having inner end surfaces 13 and 14 contacting at the time of fastening, and outer end surfaces 15 and 16 rising outward in the radial direction at a position from the inner end surfaces 13 and 14 from the center in the pipe longitudinal direction. The gasket seal portion 20 is provided at the end of the pipe 8 and is continuous in the circumferential direction of the inner end surfaces 13 and 14, and a plurality of bolt holes are provided at required intervals in the circumferential direction of the outer end surfaces 15 and 16. Provided, so that the flanges 17 and 18 are fastened by the bolt 22,
An annular bellows 30 is provided by sealing-welding one end in the width direction near the bottom of one flange outer end surface 15 and sealing-welding the other end in the width direction near the bottom of the other flange outer end surface 16 in the width direction 29.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas distribution pipe connecting device.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a pressurized fluidized bed boiler and a turbine connected to the pressurized fluidized bed boiler. The pressurized fluidized bed boiler 1 introduces compressed air therein. A pressure vessel 3 provided with a compressed air introduction port 2 on its upper side, a fluidized bed boiler main body 4 which is arranged substantially in the center of the pressure vessel 3 and can introduce compressed air from below, and the fluidized bed boiler. It is composed of a plurality of cyclones 5 arranged on the outer periphery of the main body 4, a combustion gas discharge pipe 6 connected to the upper part of the cyclones 5, and an ash cooler 7 connected to the lower parts of the cyclones 5.

Further, one end of a gas distribution pipe 8 constituted by connecting a plurality of pipes having a large diameter (diameter of 150 mm or more) by welding 8a is connected to the combustion gas discharge pipe 6 above each cyclone 5, and the gas distribution is carried out. A turbine 9 is connected to the other end of the pipe 8. In the figure, 10 is an air compressor.

In the above structure, the compressed air introduced into the pressure vessel 3 from the compressed air introduction port 2 is fed into the inside of the fluidized bed boiler body 4 from below the fluidized bed boiler body 4, and the fluidized bed boiler body 4 is supplied. Combustion is carried out while forming a fluidized bed in 4.

The combustion gas a generated by this combustion is sent to each cyclone 5, the coal ash contained in the combustion gas a is separated in each cyclone 5, and the separated coal ash is sent to an ash cooler 7 for cooling. After that, the combustion gas a from which coal ash has been separated and from which coal ash has been separated is discharged from the combustion gas discharge pipe 6, circulated in the gas distribution pipe 8 and sent to the turbine 9, and a generator (not shown) is driven to generate electricity. There is. Further, the air is compressed by the air compressor 10 driven by the turbine 9 and is again introduced into the pressure vessel 3 of the pressurized fluidized bed boiler 1 from the compressed air introduction port 2.

However, since the combustion gas a discharged from the pressurized fluidized bed boiler 1 is at high temperature and high pressure (temperature is about 890 ° C., pressure is about 10 to 15 kg / cm ² ), the gas distribution pipe 8 is about It is heated to 350 ° C. to 450 ° C., and the heat causes the gas flow pipe 8 to expand.

When the gas distribution pipe 8 expands and expands, since the pressurized fluidized bed boiler 1 and the turbine 9 are fixedly arranged, a large stress is generated in the gas distribution pipe 8 due to the expansion, and the gas distribution pipe 8 is damaged. However, the high temperature and high pressure combustion gas a may leak from the damaged portion.

In order to solve this problem, bellows 11 are arranged by welding at a plurality of points on the gas flow pipe 8,
The expansion due to expansion is absorbed to prevent damage to the gas distribution pipe 8 and prevent leakage of the combustion gas a.

On the other hand, since maintenance of the turbine 9 needs to be performed by moving the turbine 9 to another place, the gas distribution pipe 8 is cut to move the turbine 9 for maintenance. After the completion, the turbine 9 is moved again to the location where the gas distribution pipe 8 is welded and installed.

However, as described above, the large diameter (diameter 150
mm or more) or high pressure (about 10-15 kg /
The weld 8a location in the gas flow pipe 8 through which the gas fluid of (cm ² ) flows is obliged to be leak checked for safety. Therefore, the weld 8a location is checked every time the turbine 9 is installed after the maintenance is completed. However, there is a problem that the installation work is prolonged due to the leakage inspection.

In order to solve this problem, the gas distribution pipe 8
The gas flow pipe connecting device 12 is attached to the above so that the turbine 9 can be attached and detached without cutting the gas flow pipe 8 during maintenance.

Such a gas distribution pipe connecting device 12 is shown in FIGS. 4 and 5, and the gas distribution pipe connecting device 12 is
Inner end surfaces 13 and 14 that come into contact with each other at the time of fastening and the inner end surface 1
The flanges 17 and 18 having outer end surfaces 15 and 16 rising outward in the radial direction are provided by welding to the end portions of the gas distribution pipes 8 at positions closer to the longitudinal end portions of the gas distribution pipes 8 than 3 and 14. On the end faces 13 and 14, there are formed concavities and convexities that can be fitted continuously in the circumferential direction to form a gasket seal portion 20 into which a gasket 19 is fitted.
The bolts 22 are passed through a plurality of bolt holes 21 which are formed at required intervals in the circumferential direction of the flanges 5, 1.
8 can be fastened.

Due to the above-mentioned structure, when the turbine 9 is newly installed or when the turbine 9 is installed after maintenance, the gasket 19 is fitted into the recess of the gasket seal portion 20 and the gasket seal portion 2 is inserted.
After fitting the unevenness of 0, the inner end surfaces 13 and 14 are opposed to each other, the bolt 22 is inserted into the bolt hole 21, and the bolt 2
The flanges 17 and 18 are fastened by tightening 2.

[0014]

However, as described above, by merely disposing the gasket 19 in the gasket seal portion 20 and fastening the flanges 17 and 18 with the bolts 22, the combustion gas a having a high pressure can be obtained. Is the flange 1
It leaks from 7 and 18 little by little.

Since the internal fluid is at a high temperature even with this slight leak, the temperature of the tightening bolt may rise and expand, and eventually the leak may increase. Therefore, as shown in FIGS. As described above, a method is adopted in which the projections 23 and 24 formed by projecting the inner end surfaces 13 and 14 outward in the radial direction are continuously provided in the circumferential direction and the tips of the projections 23 and 24 are seal-welded 25. ing.

However, the protrusions 23 and 24 welded by the seal welding 25 have high rigidity, and if the flanges 17 and 18 are slightly moved or tilted after performing the seal welding 25, cracks are generated in the seal welding 25. Therefore, when performing the seal welding 25, first, all the bolts 22 are tightened to completely fasten the flanges 17 and 18, and then only one of the tightened bolts 22 (A in FIG. 5).
Bolt), and a part in the circumferential direction of the tips of the projections 23 and 24 (B in FIG. 5) from the facing interval 19 of the removed portion.
(Portion indicated by) is welded to the seal 25, and after the seal weld 25 at the location B is finished, the bolt 2 of the portion A removed
2 is re-tightened, then the bolt indicated by C in FIG. 5 is removed, and a part of the tips of the protrusions 23 and 24 in the circumferential direction (see FIG.
(Portion indicated by D in the figure) is seal-welded 25, and when the seal welding of the location D is completed, the bolt 22 of the portion C that has been removed is re-tightened, and the work as described above is repeated to make the protrusion 23 , 24 Seal welding around the tip 25
Had to do.

Therefore, the welding work for the seal welding 25 is troublesome and takes a very long time, so that the installation work of the turbine 9 is prolonged, and the installation work of the turbine 9 requires additional work. Since the operation of the pressure fluidized bed boiler 1 is stopped, there is a problem that the operation efficiency of the pressure fluidized bed boiler 1 is lowered due to the lengthy installation work.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a gas flow pipe connecting device capable of easily performing a welding work for sealing between flanges by welding in a short time.

[0019]

SUMMARY OF THE INVENTION According to the present invention, a gas distribution pipe is provided with a flange having a pair of inner end surfaces that come into contact with each other when they are fastened and a pair of outer end surfaces that are spaced apart from each other outside the inner end surface. At the end of the inner end face to form a continuous gasket seal portion in the circumferential direction and at the outer end face in the circumferential direction with a plurality of bolt holes at required intervals to insert bolts into the bolt holes. , A gas distribution pipe connecting device configured to connect each gas distribution pipe through a flange, wherein one end in the width direction is seal-welded to the vicinity of the bottom of the flange outer end surface of one gas distribution pipe and the other in the width direction. An annular bellows, the end of which is seal-welded, is provided in the vicinity of the bottom of the flange outer end surface of the other gas flow pipe.

Further, according to the present invention, a step portion which is continuous in the circumferential direction is formed at the bottom of the outer end surface of the flange, one end of the bellows in the width direction is seal-welded to one step portion, and the width of the bellows is attached to the other step portion. The other end of the direction is seal welded.

[0021]

According to the present invention, when the flange is fastened, the gasket is first fitted in the gasket seal portion, the annular bellows is arranged at the bottom of the outer end face, and the inner end faces are opposed to each other, and a small number of bolts (for example, Tighten the four bolts at the opposite positions.

Then, one end in the width direction of the annular bellows is seal-welded to one flange and the other end in the width direction is seal-welded to the other flange from between the outer end faces of the flanges between the tightened bolts. Then, when the welding work is completed, all bolts are tightened.

During the final bolt tightening work, the opposing flanges approach each other to compress the gasket, but at this time, the movement of the flanges is absorbed by the bending of the bellows, so that an unreasonable force is required for the seal welding. Is not added,
Therefore, the seal welding is not damaged and gas leakage can be completely prevented.

Furthermore, since the bellows having flexibility can be used for welding the bellows with only a small number of bolts tightened at the beginning of the flange fastening operation, the length between the bolts is long. Seal welding can be performed continuously over a distance, and thus the seal welding operation can be performed easily and in a short time.

Further, in the present invention, a step portion which is continuous in the circumferential direction is formed at the bottom of the outer end surface of the flange, and the end portion in the width direction of the bellows is seal-welded to one and the other of the step portions, thereby performing seal welding. Work becomes easier and reliable seal welding becomes possible.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show one embodiment of the gas distribution pipe connecting device 26 of the present invention. The same parts as those of the conventional one shown in FIGS. The description is omitted.

As shown in FIGS. 1 and 2, inner end surfaces 13 and 14 contacting each other during fastening, and outer end surfaces 15 rising radially outward from the inner end surfaces 13 and 14 at a position closer to the center in the longitudinal direction of the gas flow pipe 8. Flanges 17, 18 with 16 and
Has a large diameter (diameter 150 mm) through which the combustion gas a flows.
Gasket seal which is provided by welding to the end portion of the gas flow pipe 8) and has the inner end surfaces 13 and 14 formed with concavities and convexities that can be continuously fitted in the circumferential direction and fitted with the gasket 19. The part 20 is formed.

Further, the outer end surfaces 15 of the flanges 17 and 18,
16 Steps 27 and 28 are continuously formed at the corners of the bottom in the circumferential direction, and one side in the width direction is seal-welded 29 to one side of the steps 27 and 28 and the other side is seal-welded 29 in the width direction. An annular bellows 30 having a corrugated vertical side surface is arranged. Further, the bolts 22 are passed through a plurality of bolt holes 21 formed in the outer end surfaces 15 and 16 in the circumferential direction at a required interval.
Both flanges 17 and 18 are fastened.

Next, the operation of the above embodiment will be described.

In this embodiment, when the turbine 9 is newly installed or installed after the maintenance of the turbine 9, the annular gasket 19 is first fitted into the recess of the gasket seal portion 20 and the annular bellows 30.
Are disposed on the bottoms of the outer end surfaces 15 and 16, and the concave and convex portions of the gasket seal portion 20 are fitted to the inner end surfaces 13 and 1.
4 bolts 4 facing each other
Tighten 2 (bolt indicated by E in FIG. 2). At this time, the bellows 30 is formed in advance so that the widthwise end of the bellows 30 faces upward and coincides with the upper end of the facing surface of the step.

When the four bolts 22 are tightened, the seal welding 2 between the end portion in the width direction of the bellows 30 and the step portions 27 and 28 is performed.
9 is continuously performed from the outer end surfaces 15 and 16 between the bolts 22 over a long distance indicated by F in FIG. 2, and seal welding 29 in the range of F in FIG. When the welding work on the circumference is completed, another bolt hole 21
Also, the bolts 22 are inserted and tightened by all the bolts 22 to complete the fastening work of the flanges 17 and 18.

When the bolts 22 are tightened at the end of the above-described fastening work of the flanges 17, 18, the flanges 17,
Although 18 approaches each other and compresses the gasket 19, since the movement of the flanges 17 and 18 is absorbed by the bending of the flexible bellows 30, an unreasonable force does not act on the seal welding 29, Therefore, the seal weld 29 is not damaged, and the function of the gasket 19 arranged in the gasket seal portion 20 and the leakage of the combustion gas a can be completely prevented.

Further, as described above, the flanges 17, 1
Even if the bolts 22 are tightened at the end of the fastening work of 8, the seal welding 29 is not damaged. Therefore, the welding work of the bellows 30 should be performed with only the four bolts 22 fastened at the beginning of the flange 17, 18 fastening work. Can be done,
Therefore, the bolt 2 for welding the bellows 30
Since the distance between the two is greatly expanded and the circumferential portion F of the bellows 30 can be continuously welded at once, the welding work of the seal welding 29 can be performed easily and in a short time.

Further, the outer end surface 1 of the flanges 17 and 18
Since the step portions 27 and 28 are formed at the corners of the bottom of the bellows 5 and 16 and the welding points of the bellows 30 are the step portions 27 and 28, the welding work is facilitated and reliable seal welding 29 is performed.
Becomes possible.

As described above, by efficiently performing the work of the seal welding 29, the installation work of the turbine 9 can be performed in a short period of time, so that the operation period of the pressurized fluidized bed boiler 1 is stopped. Since the length is shortened, the operating efficiency of the boiler 1 can be improved.

In the embodiment of the present invention, the ring-shaped bellows 30 having the corrugated longitudinal side surface has been described, but various shapes may be used as long as they have flexibility. Further, although the case where the fluid flowing in the gas distribution pipe 8 is the combustion gas a of high temperature and high pressure has been described in the present embodiment, the present invention is applicable to a pipe through which highly toxic gas flows, which deviates from the gist of the present invention. It goes without saying that various changes can be made within the range not covered.

[0038]

According to the present invention, since an annular bellows is disposed near the bottom of the outer end face of the flange and the widthwise end of the bellows is seal-welded to the flange, the bolt tightening work is performed. It is possible to absorb the movement of the flange that occurs at the time of deformation by the deformation of the bellows, and no unreasonable force acts on the seal welding, so that the leak of gas can be completely prevented without damaging the seal welding. . By using a flexible bellows,
The seal welding work of the bellows can be performed with only a small number of bolts tightened at the beginning of the flange fastening work, so that the distance between the bolts for performing the bellows welding work is significantly widened and a long distance can be maintained. Since seal welding can be performed continuously, welding work can be performed easily and in a short time. Further, in the present invention, since the step portion is continuously formed in the outer end bottom portion of the flange in the circumferential direction and the width direction end portion of the bellows is seal-welded to the step portion, the welding work is facilitated. And reliable seal welding is possible.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of a gas distribution pipe connecting device of the present invention.

FIG. 2 is a view taken along the line II-II of FIG.

FIG. 3 is an overall view showing a general example of a pressurized fluidized bed boiler and a turbine connected to the pressurized fluidized bed boiler.

FIG. 4 is a vertical cross-sectional side view showing an example of a conventional gas distribution pipe connecting device.

5 is a view taken along the line VV of FIG.

[Explanation of symbols]

 8 Gas distribution piping 13,14 Inner end surface 15,16 Outer end surface 17,18 Flange 20 Gasket seal part 21 Bolt hole 22 Bolt 26 Gas distribution pipe connecting device 27,28 Step part 29 Seal welding 30 Bellows

Claims (2)

[Claims] 1. A flange provided with a pair of inner end surfaces that come into contact with each other at the time of fastening and a pair of outer end surfaces that are spaced apart from each other on the outer side of the inner end surface, is provided at an end portion of the gas flow pipe. While forming a continuous gasket seal portion in the circumferential direction of the end face, a plurality of bolt holes are provided at a required interval in the circumferential direction of the outer end face, and bolts are passed through the bolt holes to form a flange for each gas flow pipe. A gas flow pipe connecting device configured to be connected via, wherein one end in the width direction is seal-welded to the vicinity of the bottom of the flange outer end surface of one gas flow pipe and the other end in the width direction is the other gas flow pipe. A gas distribution pipe connecting device, wherein an annular bellows, which is seal-welded, is provided in the vicinity of the bottom portion of the flange outer end surface. 2. A step portion that is continuous in the circumferential direction is formed on the bottom of the outer end surface of the flange, one end of the bellows in the width direction is seal-welded to one step portion, and the other end of the bellows in the width direction is welded to the other step portion. The gas distribution pipe connecting device according to claim 1, wherein the seal is welded.