JPH08281468A - Tube repair welding method and equipment therefor - Google Patents

Abstract

PURPOSE: To rapidly repair a damaged place during driving without lowering the temperature inside a furnace in a welding method and the equipment therefor in order to repair the damage to a furnace wall tube, etc., of the generation of electrical energy. CONSTITUTION: At a time of welding respective joining parts of circumference by removing the damaged part generated on a furnace wall tube (existing tube) 01, and inserting a new tube 01 in the removed part, opening parts 22 are drilled on the the external face sides of furnace wall of the existing tube 02 and the new tube 02, a small welding torch 06 is inserted in the inside of tube from this opening 22, the circumference joining parts of the existing tube 01 and the new tube 02 are welded automatically from the inside, then the insert tube matching to the opening part is attached and the periphery is TIG-welded automatically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a repair welding method and apparatus applied to a furnace wall tube or the like of a power generation boiler.

[0002]

2. Description of the Related Art Conventionally, when a boiler wall tube of a boiler of a thermal power plant is damaged during operation, after lowering the temperature inside the furnace, scaffolding materials are carried into the furnace through a manhole, and after scaffolding is assembled, the furnace wall is assembled. The pipe was repair welded.

In this case, for the circumferential welding of the damaged furnace wall tube, an operator is arranged on the inner surface and the outer surface of the furnace, and the welding is carried out for each half circumference.

[0004]

By the way, as described above, when the furnace wall tube of the boiler of the conventional thermal power plant is damaged during operation, the scaffolding material is carried into the furnace through the manhole after lowering the temperature in the furnace. After the scaffold was assembled, the furnace wall tube was repaired and welded.

Therefore, there are problems in terms of time required for cooling the temperature in the furnace, attachment of scaffolds, disassembly period, and man-hours.

It is an object of the present invention to solve these problems and provide a new pipe repair welding method and apparatus for repair welding a damaged boiler furnace wall pipe during boiler operation.

[0007]

In order to achieve the above object, the pipe repair welding method of the present invention is designed to cut and remove the damaged portion of the damaged pipe when repair welding a damaged boiler furnace wall pipe during boiler operation. After that, insert a new pipe, as a method of performing welding of the existing pipe and the new pipe from the outer surface side of the furnace wall, sandwiching the circumferential joint portion of the existing pipe and the new pipe, on the outer surface side of the circumferential groove furnace wall, A small automatic TIG welding torch An opening is formed to allow a part of the torch head to be inserted into the inner surface of the pipe, and the circular groove portion excluding the opening is first used to perform automatic TIG welding from the inner surface of the pipe using the inserted welding torch. Then, after the insertion tube that fits the opening is temporarily attached to the opening, the outer circumference of the attachment portion of the insertion tube is manually TIG welded.

As a welding device for carrying out the above-mentioned pipe repair welding method, a small TIG welding torch to be inserted into the inner surface of the pipe, a microminiature arc voltage control slide for moving the welding torch in the diameter direction in the pipe, and a welding wire. A guide nozzle, a fiberscope for welding condition monitoring, etc. are supported by a rotary support arm that can swivel around the pipe axis, and the support arm can be inserted into the pipe, and connected to the rotary support arm on the outer surface of the pipe. A welding torch swivel motor, a welding wire feeder, a welding wire coil, and the like are arranged, and further, a rotating shaft of the welding torch arranged inside the pipe as a swivel means of the welding torch and a swivel motor arranged outside the pipe are belted. Those linked by, for example, are preferred.

[0009]

[Operation] When the boiler furnace wall tube is damaged during boiler operation, the repairing method is required only from the outside of the furnace wall as a requirement for the repairing method of the damaged wall tube even if the temperature inside the furnace does not drop to a predetermined temperature. A construction method and equipment capable of welding are required.

The structure of the furnace wall tube includes a type in which the tubes are directly welded and a type in which a strip having a width of 10 mm is inserted between the tubes and the strip and the tubes are welded. Since there is a welded portion in the diametrical direction of the pipe, when welding from the outer surface, a groove that can be welded before the diameter is required.

In view of these points, in the present invention, when a part of the furnace wall tube is damaged and burst, a damaged tube is removed, a new tube is inserted, and a circumferential joint with the existing tube is about 210 to 210. 270
This is based on the idea that the inner surface is welded for 60 degrees and the remaining 150 to 90 degrees is welded on the outer surface. The furnace is made by sandwiching the circumferential joint between the new pipe and the existing pipe inserted as openings required for inner surface welding. Approximately 210-2 by making a hole on the outside of the wall in the range of about 150-90 degrees and inserting a welding torch through this opening.
70 degrees is automatically TIG-welded from the inner surface of the pipe, and after inserting the bead start and end portions, an insertion tube having an oval shape or the like matching the opening is attached to the opening, and the periphery of the opening is welded by TIG welding.

As a result, even if the boiler furnace wall tube is damaged during operation, it can be repaired quickly and effectively.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a conceptual diagram of a pipe repair welding method according to an embodiment of the present invention, FIG. 2 is a plan view of a circumferential TIG welding condition of a pipe inner surface in the method of the embodiment, and FIG. 3 is a pipe inner surface circle used in the method of the embodiment. It is a side view of a circumference TIG welding device. In addition, FIG.
FIG. 5C is a perspective view showing the procedure of the repair method, and FIG.
(E) is a plan view showing a pipe inner surface welding procedure of the repair method, and FIG. 6 is a diagram showing an example of damage to a furnace wall pipe to which the present invention is applied.

FIG. 1 shows a furnace wall tube (existing tube) 01 having a damaged portion 21 shown in FIG.
2 is inserted between the removed portions and the joints are circumferentially welded to each other, an opening 22 is bored on the outer surface side of the furnace wall in the existing pipe 01 and the new pipe 02, and the opening 22 is formed through the opening 22 shown in FIG. Insert the small welding torch 06 shown in
This is a method of automatically welding the circumferential joint of the new pipe 02 from the inner surface, then attaching the insertion pipe 03 that fits the opening 22 and manually performing TIG welding on the periphery thereof. In addition, 04 is an inner surface bead and 05 is an outer surface bead.

FIG. 2 shows the welding condition of the opening 22 provided on the outer surface side of the furnace wall of the existing pipe 01 and the new pipe 02 in a cross-section of the pipe. The width of the opening 22 is about 90. ~ 150 °
The width is such that a small welding torch 06 or the like can be inserted.

Numeral 04 is an inner bead, numeral 07 is a tungsten electrode attached to the tip of the welding torch 06, and numeral 20 is a welding wire guide nozzle.

As for the dimension of the opening 22 in the tube axis direction, as shown in FIG. 3, a welding torch 06, a small slide 08 with arc voltage control, a motor 09 and its motor 09 are rotated along the circumferential direction of the tube. The support shaft 11 and the like for allowing the insertion are dimensioned so as to be inserted into the inner surface of the pipe.

FIG. 3 is a schematic view of a pipe inner surface automatic TIG welding apparatus. In FIG. 3, reference numeral 12 is an arm for supporting the welding torch 06 and the slide 08 inserted in the pipe inner surface on the pipe outer surface side. 11 and the other end is a welding torch 0
6 rotation motor 13 and welding wire feeder 19
Are linked to.

Reference numeral 14 is a transmission belt for rotating the welding torch 06, and 08 is an electric slide for moving the welding torch 06 in the pipe radial direction, which has a control mechanism (not shown) for keeping the welding arc voltage constant. Equipped with motor 09
It is configured to transmit the rotational force of (1) to the slide 08 via a pair of spur gears 10 that mesh with each other and move the slide 08.

Although the welding head such as the wire feeding device 19 on the outer surface of the pipe is not shown, it is fixed by using a magnet or the like with the existing pipe 01 as a reference, and the welding head is arranged in the pipe axial direction between the fixed portion and the welding head. Connect via a slide for position adjustment to move.

Reference numeral 04 denotes an inner bead, and although not shown, a small-diameter fiberscope is attached near the welding torch 06 to monitor the welding arc and the tungsten electrode 07.

In the figure, 15 is a cable, 16 is a gas hose, 17 is a wire reel, 18 is a welding wire, and 20 is a wire guide nozzle.

Next, the operation of the present invention will be described.
In the present invention, as shown in FIG. 6, when a part of the furnace wall tube 01 is damaged and burst, as shown in FIGS.
After removing the, the new pipe 02 is inserted, the opening 22 is provided on the outer surface side of the furnace wall by sandwiching the circumferential joint portion with the existing pipe 01, and the circumferential joint portion is subjected to automatic TIG welding from the inner surface of the pipe. The insertion pipe 03 that fits the opening 22 is fitted and attached, and the insertion pipe 03 is attached.
The elliptic joint part is manually TIG welded.

The procedure is shown in FIGS. 4 and 5. In FIG. 4, (a) is a state in which the circumferential joint of the existing pipe 01 and the new pipe 02 is welded from the inner surface to finish, (b) is a state in which the insertion pipe 03 fitted to the opening 22 is temporarily attached, (c) ) Shows the state where the elliptic joint of the insertion tube 03 is manually TIG-welded.

Further, in FIG. 5, (a) shows the existing pipe 01.
(B) is a state in which the small automatic TIG welding torch 06 is inserted into the existing pipe 01 through the opening 22, and (c) is a state in which the welding torch 06 is positioned at the welding start point. (d) shows a state in which the back pass welding in the first pass is completed, and (e) shows a state in which the extra welding is completed and the welding torch 06 is removed.

As described above, according to this method, the damaged portion 21 of the furnace wall tube 01 can be repaired only from the outer surface side of the furnace wall.

Although one embodiment of the present invention has been briefly described above, the present invention is not limited to the above embodiment and various modifications can be made within the scope of the technical idea of the present invention. Belong to the technical scope of.

[0028]

As described above, according to the pipe repair welding method and apparatus of the present invention, even if the boiler furnace wall pipe of the power plant is damaged during operation, the temperature inside the furnace can be lowered to a predetermined temperature. There is an effect that the damaged wall tube can be repaired quickly and at low cost.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a repair method according to an embodiment of the present invention.

FIG. 2 is a plan view of a circumferential TIG welding condition on the pipe inner surface in the embodiment.

FIG. 3 is a side view of a pipe inner circumferential TIG welding apparatus in the same embodiment.

4 (a), (b) and (c) are perspective views showing the procedure of the repairing method of the same embodiment.

5 (a) to (e) are plan views showing a pipe inner surface welding procedure of the repairing method of the embodiment.

FIG. 6 is a perspective view showing an example of damage to a furnace wall tube which is a target of the present invention.

[Explanation of symbols]

 01 Furnace wall tube (existing tube) 02 New tube 03 Insertion tube 04 Inner bead 05 Outer bead 06 Welding torch 07 Tungsten electrode 08 Slide 11 Support shaft 12 Support arm 13 Rotating motor 14 Belt 15 Electric cable 16 Gas hose 17 Wire reel 18 Welding wire 19 Wire feeder 20 Wire guide nozzle 21 Damaged part 22 Opening

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuhiro Koga 1-1-1, Wadazaki-cho, Hyogo-ku, Kobe Sanryo Heavy Industries Ltd. Kobe Shipyard (72) Inventor Hisamitsu Uchiya Wadazaki-cho, Hyogo-ku, Kobe 1-1-1 Sanryo Heavy Industry Co., Ltd. Kobe Shipyard (72) Inventor Shinji Morioka 1-1-1 Wadazakicho, Hyogo-ku, Kobe Sanryo Heavy Industry Co., Ltd. Kobe Shipyard

Claims (2)

[Claims] 1. When repairing and welding a damaged boiler furnace wall pipe during boiler operation, after cutting and removing the damaged portion of the damaged pipe, a new pipe is inserted and the existing pipe and the new pipe are welded to each other. As a method to be performed from the outer surface side, an opening portion for inserting a part of the small automatic TIG welding torch head into the inner surface of the pipe on the outer surface side of the furnace wall of the circumferential groove by sandwiching the circumferential joint portion of the existing pipe and the new pipe. Perforated, first peripheries of the circumferential groove excluding the opening from the inner surface of the pipe, perform automatic TIG welding with the inserted welding torch, and then temporarily attach an insertion pipe that fits the opening to the opening, A repair welding method, characterized in that the outer periphery of the temporarily attached portion of the insertion tube is manually TIG welded. 2. A small TIG welding torch to be inserted into the inner surface of the pipe, a microminiature arc voltage control slide for moving the welding torch in the diameter direction inside the pipe, a guide nozzle for the welding wire, a fiberscope for monitoring the welding condition, and the like. It is supported by a rotating support arm that can swivel around the heart,
The supporting arm can be inserted into a pipe, and a rotating motor for the welding torch, a welding wire feeding device, a coil of the welding wire, and the like are arranged on the outer surface of the pipe so as to be connected to the rotation supporting arm, and further, the welding torch has a coil. A pipe repairing TIG welding device characterized in that a rotating shaft of a welding torch arranged inside the pipe as a rotating means and a rotating motor arranged outside the pipe are connected by a belt or the like.