JPH0639062B2 - Tube extraction method and tube extraction tool for boilers, heat exchangers, etc. - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for extracting a tube of a boiler or a heat exchanger and a tube extracting tool used in the method, and in particular, a thick barrier or a thick tube is used. It was developed for the purpose of improving the efficiency of pipe extraction work by facilitating the difficult pipe extraction work of a large-scale device and facilitating the extraction from either the expansion side or the pipe cutting side of the boiler tube sheet. .

<Prior Art> Many boilers and heat exchangers have a structure in which a large number of tubes are roller-rolled or welded and fixed in an air-tight or water-tight manner between two tube sheets by rolling them into tube holes in the tube sheets. ing. Conventionally, when repairing these boilers and the like, the removal and replacement of damaged pipes have been performed in the following procedure.

(a) Hang the roller expansion part of the pipe in the longitudinal direction at one or two places with blunt gutters, and make a split groove, taking care not to damage the pipe hole.

(b) The edge of the smoke pipe is bent up with a chisel. If the water pipe is spread like a trumpet, cut off this part, or
Or, insert a split groove in the vertical direction. If leak-welding is performed, carefully deposit the welded iron.

(c) Apply chisel or pad to the outer circumference of the pipe end and tap it with a hammer to fold the pipe toward the inside and squeeze out.

(d) If the pipe may be cut off, gas-cut at a position 5 to 15 mm away from the roller expansion part of the pipe in advance and then remove the roller expansion part by the above method. When pulling out the entire length without cutting off the pipe, use a pulling tool to pull it out.

Such a method is described in the Boiler Handbook edited by the Japan Boiler Association, and has reached the present as the standard work of the pipe sampling method.

However, the above (a) to (c) are all chipping work with chisel and hammer, which damages the pipe hole with caution and causes leaks. He slammed his hand with a hammer, got injured, and couldn't even shake the hammer in a narrow working space, which made work extremely difficult. As a method of pulling a pipe out of a pipe hole without breaking the pipe, for example, a method in which several line welds are performed on the inner surface of the pipe and a gap is formed between the pipe hole and the pipe due to stress reduction (Japanese Patent Publication No. No. 54-5129 No. 60-86708) has been proposed, but since the end face on the fusing side of the pipe passes through a slight gap in the fusing side when extracting the fusing side of the pipe, Since vertical scratches may occur, the vertical scratches cause wetting, and are not preferable methods. A drawing device has also been proposed in which a cooling pipe for separating, which is inserted while squeezing the expanded portion of the pipe between the pipe and the pipe plate, and a pipe for expanding the pipe, which is inserted inside the crushed pipe, are concentrically arranged. (Japanese Patent Laid-Open No. 59-18389), however, this is intended for soft pipes such as copper and aluminum pipes, and steel pipes have insufficient strength.
It cannot be applied to pipes with a thickness of 100 mm or more.

Therefore, the present inventor has solved the drawbacks of the above-described work, eliminated the work of hammering and hammering, and developed a pipe extracting tool that applies a special lever, and by using it, the pipe extracting work can be performed easily. A workable method has been developed, and in Japanese Patent Publication No. Sho 60-32118, a new pipe extracting method using a special pipe extracting tool is proposed and implemented.

<Problems to be Solved by the Invention> However, since the above pipe extracting method is a method using only the extracting tool (I) of the present invention described later, the thickness of the tube plate of the boiler / heat exchanger is 30 mm. It has been found that the above becomes a little difficult, and the difficulty of work doubles when reaching 100 mm. In particular, if the tube sheet has a thickness of 80 to 100 mm and the tube hole has one or two leak-proof grooves, or the tube itself has a large thickness, for example, 5 mm or more, It became clear that the pipe extraction work was extremely difficult.

<Means for Solving Problems> The present invention is a novel tube extracting method performed by a combination of a plurality of tube extracting jigs useful for tube extraction of a large boiler or a heat exchanger using a thick tube plate or a thick tube. And a pipe extractor, the gist of which is a damaged pipe to be replaced when replacing a thick pipe such as a boiler or a heat exchanger that is inserted and fixed between the pipe holes of two thick pipe plates. In the following order (i) to (h), the boilers, heat exchangers, etc. are removed from the tube sheet in the following order.

(B) A plurality of gouging parts (4) are formed on the inner surface (3) of the tube hole (2) of the pipe (1) at intervals in the pipe length direction. (B) Gouging part (4) of the pipe (1) ) Is heated and softened with a gas flame, (c) The extractor (I) having a claw (5) provided at a position retracted by a predetermined length from the tip of the lever with a space equal to or greater than the pipe thickness is softened. Fit into the pipe end (6), and remove the pipe from the pipe hole. (D) Leave end (8) leaving the base (12) of the release part (7) slightly.
(E) The lever has a bent end (9) at the tip of the lever, and a recess (10) and a claw (11) are provided at a position retracted by a predetermined length from the end with a space equal to or greater than the pipe thickness. While pushing the release base (12) toward the inner side of the pipe with the extractor (II) having
(9) abuts on the inner surface of the pipe, locks the claw (11) to the detaching part (18) provided on the opposite side of the pipe, peels off by leverage, and melts the detaching end (8) in sequence. (F) When the extractor (II) cannot be used and there are more pipe ends, the extractor (III) having the spatula-shaped end (13) at the tip of the lever bar is used to remove the release base (12). Peeling while pushing to the inner side of the pipe, fusing the peeling end (14) in order to completely peel between the gouging part (4) of the pipe (1) from the pipe hole (2), (g) remaining pipe end Apply the extractor (I) of (6) and bend the pipe end (6) inward to make the pipe end (6) smaller than the diameter of the pipe hole (2). (H) There is a pipe end (6) In this case, tap it with a hammer and pull out the tube.

The pipe extractor used in this method has the structure shown in I to III below.

At the tip of the lever (15) and the tip of the lever (16), the extractor (I) that has a claw (5) provided in the direction of the tip of the lever at a position retracted by a predetermined length from the tip of the lever (15). An extractor having a bent end (9) and a recessed portion (10) at a position retracted from the bent end (9) by a predetermined length with a space equal to or greater than the pipe thickness and a claw (11) provided in the tip direction of the lever. A pipe extractor comprising a combination of (II) and a remover (III) having a spatula-shaped end (13) at the tip of a lever (17).

The pipe extractor consists of the above three types, regardless of the size and length of the pipe. Either one set of three leverage rods processed at one end, or both ends of the leverage rod are end-processed for two types. Book 1
It is optional whether to make a pair.

<Operation> First, a thin streak portion is formed in the longitudinal direction of the tube by gouging (a) to reduce bending stress from the outside to the inside of the tube. By heating and softening (b), the pipe between the gouging parts is easily deformed and fractured.

The pipe between the gouging portions is peeled in the longitudinal direction by the deformation of (c) by the extraction tool (I). Remove the peeled part by fusing the gas flame in (d). The removal tool (II) of (e) is peeled in the depth direction of the pipe or in the opposite direction by lever action, and the gas flame sequentially removes the peeled portion by fusing. If there are remaining pipe ends, (f)
The stripping tool (III) is used to further peel in the depth direction, the peeled portion is melted and removed by a gas flame, and finally the pipe between the gouging portions is peeled from the tube sheet. Finally, the operation of the removal tool (I) (g) is performed to make the remaining tube end smaller than the hole diameter to facilitate the removal of the tube from the tube hole.

The pipe extractor consists of a lever with three types of tip processing, and the nail (5) of the extractor (I) is a pipe end (6) that opens like a trumpet.
Bends inwardly, and the claw (11) of the extractor (II) is effective for inward bending of the tube in the middle part of the tube plate, and when used from the opposite side, Can be a contact fulcrum. The tube removal operation can be performed either on the tube expansion side or on the opposite side of the tube sheet. The workability of the worker may be considered and the workability may be improved. A thin tube sheet,
Alternatively, when the tube is removed from the side opposite to the tube expansion side, it is preferable to use the extraction tool (II) in which the space between the bent end (9) and the claw (11) is narrow (IIb).

The spatula-shaped end (13) of the extractor (III) has a shape that effectively acts on the inward bending of the tube near the inner side of the tube sheet.

The following will specifically describe the tube extracting method and the tube extracting tool of the boiler, the heat exchanger, etc. of the present invention with reference to Examples.

<Embodiment 1> FIGS. 1 to 10 are explanatory views showing the deformation of a pipe in the order of the method of the present invention, in which (a) of each drawing is a cross-sectional view and (b) of each drawing is a tube sheet expansion. It is the side view seen from the side. FIG. 11 is a cross-sectional view when the pipe is pulled out from the side opposite to the pipe expanding side.

12 and 13 are a side view and a plan view of the extractor (I), and FIG.
FIG. 15 is a side view and a plan view of the extractor (IIa), and FIG. 16 is a side view of the extractor (IIb). 17 and 18 are a side view and a plan view of the extractor (III).

A thick tube that is inserted and fixed between the tube holes of two thick tube plates (80 mm), and has a leak-prevention groove inside the two tube holes. Part diameter 50 mm, t = 4 m
The damaged tube in m) was removed from the tube sheet in the following order. First of all, as shown in Fig. 1 (a), the inner surface (3) of the portion of the pipe (1) inserted in the pipe hole (2) is melted while generating an arc flame with an arc welding machine. Meanwhile, a plurality of gouging portions (4) are formed at intervals in the pipe length direction. Next, as seen in FIG. 2, the space between the gouging portions (4) of the tube (1) was heated and softened by a gas flame. Then, as shown in FIG. 3, the pipe end (6) obtained by softening the extractor (I) having the claw (5) provided at a position retracted by about 150 mm from the tip of the lever is provided at a distance equal to or larger than the pipe thickness. ), And detached the tube from the tube hole. Next, the detachment section
After removing the detached end (8) by fusing with a gas flame leaving the base (12) of (7) slightly, a bent end is attached to the tip of the lever as shown in FIGS. 5 (a) and 14. (9) and has almost 1 from the tip
At the position retracted by 00 mm, leave a recess (1
(0) and a claw (11) with the extractor (IIa) pushing the release base (12) toward the inner side of the pipe to remove it, and the release end (8)
Were blown out in sequence. When the extractor (IIa) cannot be used and there is an additional pipe end, the extractor (III) having a spatula-shaped end (13) at the tip of the lever is used to remove the detachment base (1).
2) was peeled while pushing it toward the inner side of the pipe, and the peeled end (14) was sequentially melted to completely peel between the gouging part (4) of the pipe (1) from the pipe hole (2). Here, as shown in FIG. 9, the extractor (I) is applied to the remaining pipe end (6) and the pipe end (6) is bent inward to make the pipe end (6) smaller than the diameter of the pipe hole (2). Then, as shown in FIG. 10, the pipe was pulled out by tapping it with a hammer (21) through a metal plate (20).

In the above pipe extraction method, although the tube plate of the heat exchanger has a large thickness, has a leak-proof groove, and has a large wall thickness of the tube itself, the tube extraction work can be performed extremely easily. Of.

<Example 2> As described above, the tube removing operation can be performed on either the tube expansion side or the opposite side of the tube sheet. From the workability of the operator, the first embodiment was performed from the pipe expanding side, but the following shows an embodiment in which the pipe is removed from the side opposite to the pipe expanding side. The extractor was almost the same as that shown in (IIa), and the one (IIb) shown in Fig. 16 in which the space between the bent end (9) and the claw (11) was formed narrowly was used.

In this example, two thick tubes (20 mm) are provided with leak-proof grooves in one tube hole.
mmφ, expanded tube diameter 50 mm, t = 4 mm) were removed from the tube sheet in the following order.

Similar to the first embodiment, first, a plurality of gouging portions (4) are formed on the inner surface (3) of the portion inserted from the cutting portion (22) into the pipe hole (2) of the pipe (1). Next, similarly, the space between the gouging portions (4) was heated and softened with a gas flame. Then, the extraction tool (I) was fitted in the softened pipe end (6) from the direction opposite to that shown in FIG. 3, and the pipe was detached from the pipe hole in order to reduce the cut portion pipe end. Next, after leaving the leaving end (8) of the leaving part (7) slightly by fusing and removing the leaving end (8) with a gas flame, as shown in FIGS. 11 and 16,
There is a bent end (9) at the tip of the lever and it is almost 22 mm from the tip.
To the inner surface of the expanded pipe from the direction opposite to that of the first embodiment, using the extractor (IIb) having the recess (10) and the claw (11) at a distance larger than the pipe thickness. The claws (11) were brought into contact with each other, the claws (11) were locked to the disengagement parts (18) provided on the opposite side of the tube expansion, and peeled and removed by the lever action.

In the case of a water tube boiler, if the workability inside the drum or inside the header (header) is poor, it is not necessary to perform the work inside, and the pipe removing work may be performed on the side where the work is easy on the outside of the drum. Alternatively, when a smoke chamber is provided on the tube expansion side like a furnace tube smoke tube type boiler and it is difficult for people to enter, the tube expansion may be performed from the wide side inside the drum, that is, the cutting section.

In the case of the second embodiment, the extractor (III) is unnecessary.

<Effects of the Invention> With the method and the pipe extractor of the present invention, when the thickness of the tube plate of the boiler, the heat exchanger, etc. is large and the tube hole is provided with a leak-tight groove, Even if it is thick,
The pipe extraction work has become extremely easy. The present invention is useful because the pipe removing operation can be performed from either the pipe expanding side or the cutting side.

[Brief description of drawings]

1 to 10 are explanatory views showing the deformation of the pipe in the order of the method of the present invention, wherein (a) of each of FIGS. 1 to 9 is a sectional view,
(B) of each figure is a side view seen from the outside of the tube sheet. FIG. 10 is a sectional view of the same. FIG. 11 is a cross-sectional view when the pipe is pulled out from the side opposite to the pipe expanding side. 12 and 13 are a side view and a plan view of the extractor (I), and FIG.
Figures and 15 are side and plan views of the extractor (IIa).
The figure is a side view of the extractor (IIb). 17 and 18 are a side view and a plan view of the extractor (III). (1) …… pipe, (2) …… pipe hole (3) …… inner surface, (4) …… gouging part (5) …… claws, (6) …… pipe end (7) …… disconnection part, (8) ...... Disengagement end (9) ...... Bend end, (10) ...... Recessed part (11) ...... Claw, (12) ...... Disengagement base (13) ...... Spatula end, (14) ...... Peeling edge (15) (16) (17) …… Lever, (20) …… Attachment (21) …… Hammer

Claims (2)

[Claims] Claim: What is claimed is: 1. A boiler, which is inserted and fixed between two tube holes of two thick tube plates, and a boiler for removing damaged pipes to be replaced in order from a tube plate when replacing a thick tube such as a heat exchanger. , (B) forming a plurality of gouging parts (4) at intervals in the pipe length direction on the inner surface (3) of the insertion hole (2) of the pipe (1). ) A gas flame heats and softens the space between the gouging parts (4) of the pipe (1), and (c) A pawl (5) is provided at a position retracted from the tip of the lever for a predetermined length with a gap greater than the pipe thickness. The extraction tool (I) is fitted into the softened pipe end (6) to separate the pipe from the pipe hole (2). (D) The separation end (8) leaving the base (12) of the separation part (7) slightly.
(E) It has a bent end (9) at the tip of the lever, and a recess (10) is formed at a position retracted by a predetermined length from the tip with a space equal to or greater than the pipe thickness.
With the extraction tool (II) having a claw (11) and the release base (12)
Peeling while pushing to the inner side of the pipe, or bending end from the opposite direction.
The (9) is brought into contact with the inner surface of the pipe and the claw (11) is locked to the disengagement portion (18) provided on the opposite side of the pipe, and is peeled off by leverage.
(F) When the removal tool (II) becomes unusable and there are more pipe ends, the removal tool has a spatula-shaped end (13) at the tip of the lever. In (III), push the release base (12) to the inner side of the pipe to peel off, peel off the peeling end (14) in sequence, and completely remove the gap between the gouging part (4) of the pipe (1) from the pipe hole (2). (G) Apply the extraction tool (I) to the remaining pipe end (6) and bend the pipe end (6) inward to make the pipe end (6) smaller than the diameter of the pipe hole (2). H) Tap this with a hammer etc. to pull out the tube. 2. An extractor (I) having a claw (5) provided at a position retracted by a predetermined length from the tip of the lever bar (15) and provided in the distal direction of the lever bar with a space equal to or greater than the tube thickness, and a lever bar. (16) A bent end (9) is provided at the tip, and a recess (10) is provided at a position retracted from the bent end (9) by a predetermined length with a space equal to or greater than the pipe thickness, and a claw (11) provided in the tip direction of the lever. ), And a pulling tool (III) having a spatula-like end (13) at the tip of a lever (17).