JPS62155406A - Method of constructing or repairing boiler tube - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides a method for constructing or repairing a boiler duplex.
I171'.

[Prior Art] For example, boiler tubes used in paper mills and the like generally have a large number of studs welded along at least part of their outer periphery in order to protect them from corrosion and increase their heat insulation effect. I support it. The refractory material layer is usually formed by spraying or coating a mixture of a refractory material raw material and a binder onto a boiler tube in which a large number of studs have been welded.

The refractory material layer J3 and the number of studs supporting the refractory material layer vary depending on the boiler tube used, but
Normally, the refractory layer wears out and the tip of the stud wears out into a tapered shape in about 3 to 5 years. In reality, even in the same boiler tube, there are variations in the state of wear of the refractory material layer and studs. Therefore, it is necessary to perform regular inspections.
It is necessary to apply m. The conventional repair method is to remove the refractory material layer and surface deposits, and remove the studs that require repair from the base or at a predetermined height among the studs that have been welded around the boiler tube. A known method is to cut the material flat, to weld a repair stud to the cut surface by manual welding, and to apply a layer of refractory material to the cut surface using the above-mentioned method.

In such a repair method, it is necessary to cut out the worn stud by one piece of wood, which takes a considerable amount of time and effort, and is not efficient. In order to save time and effort in such repairs, methods for repairing worn studs without exposing them to the light are disclosed in Japanese Patent Laid-Open No. 59-189078 and Japanese Patent Laid-Open No. 189078.
This method is proposed in Japanese Patent No. 159-195002.

[Problem to be solved by the invention 1 By the way, when constructing or repairing boiler tubes used in paper factories, etc., work must be done in a substantially closed and relatively narrow space. Because it is forced to
Even if the conventional method disclosed in the above-mentioned publication is used, the number of studs to be welded is extremely large.
This is extremely painful work for workers, and the construction and repair of boiler tubes involves not only stud welding as mentioned above, but also the formation and repair of a refractory layer. Conventionally, repair work has been carried out exclusively by spraying or coating as mentioned above, which not only takes time, but also creates an extremely poor atmosphere due to dust, etc.
Working continuously for long periods of time is physically and psychologically difficult. As a result, even using methods such as those disclosed in the above-mentioned publications, the construction and repair of boiler tubes remains laborious, time-consuming, and considerable in cost.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to reduce the number of studs to be welded around the boiler duplex in order to eliminate the drawbacks of the conventional methods as described above, and to provide a refractory material layer that can be welded simultaneously with the studs to the boiler tube. The purpose is to provide a method for forming or repairing boiler tubes.

[Means for Solving the Problem] In order to achieve the above object, the boiler tube construction or repair method according to the present invention provides a method for constructing or repairing a boiler tube by attaching studs to each stud in advance in a refractory material made of ceramic material. The head of each stud in the hole is fixed by welding directly to the boiler tube or on the tip of the worn stud on the boiler duplex using the stud welding method. It is characterized by being filled and coated with a material to form a refractory material layer.

[Function] In the boiler tube construction or repair method according to the present invention, the refractory material forming the refractory layer can be removed at the same time as the studs are welded to the boiler tube. The refractory material to be attached to the boiler tube is preferably formed into a rectangular plate shape with fixed dimensions,
The required number of stud mounting holes are provided. Therefore, not only the construction of the boiler tube but also the repair work can be carried out relatively easily in a short time. For example, when repairing a boiler tube, the repair stud may be welded directly onto the burnt-out refractory layer, or by removing the burnt-out refractory layer if necessary. The required size of repair fireproofing material can be installed.

[Examples] Examples of the present invention will be described below with reference to the accompanying drawings.

1 and 2 show an embodiment of the boiler tube construction method according to the present invention, in which 1 is a boiler duplex, and rectangular plate-shaped refractory materials 2 made of ceramic material are attached to each plate of the boiler tubes 1. The studs provided on the shaped refractory material 2 are attached by welding the studs 3 to the boiler tube 1 through the holes 2a using a stud welding method. As shown in FIG. 2, the length of each stud 3 is shorter than the thickness of the refractory material 2, and when welded to the boiler tube 1, a dish-shaped collar is integrally attached to the head of each stud 3. 3a is sunk into the stud mounting hole 2a and welded to the dish-shaped collar 3 of each stud 3.
The recess above a is filled with a ceramic material 4 similar to the refractory material 2. The dish-shaped collar 3a of each stud 3 acts as a support member for supporting the ceramic material 4. In addition, as shown in FIG. 3, the rectangular plate-shaped refractory material 2 used has a stepped portion 2b on the peripheral edge, and the stepped portions 2'01fi of the adjacent plate-shaped refractory materials 2 overlap and are continuous. A layer of refractory material is formed.

FIG. 4 shows an embodiment of the boiler tube repair method according to the present invention. On the left side of the figure, a worn stud 6 on the boiler tube 5 is shown, and the tip of this stud 6 is rounded and tapered. . A repair stud 7, which has a dish-shaped collar 7a integrally attached to the sea urchin head shown on the right side of the figure, is directly welded onto this worn out rounded and tapered tip. A plate-shaped refractory material 8 for repair made of a ceramic material similar to the refractory material 2 shown in FIGS.
Its stud mounting is supported through the hole 8a. The upper part of the hole 8a for stud attachment is filled with a filler 9 made of a ceramic material similar to the plate-shaped refractory material 8 for repair.

In each of the above-mentioned embodiments, each stud provided in each plate-shaped refractory material 2, 8 is mounted through a hole 2a.

8a is cylindrical, but can be tapered as shown in FIG. 5 to securely engage the head of a stud welded to the boiler tube.

Furthermore, although a plate-shaped refractory material is used in the illustrated embodiment, it may be made of any shape such as a block shape or a curved shape, if necessary.

[Effects of the Invention] As explained above, according to the method of the present invention, each stud made of a fireproof ceramic material (A) is inserted through a hole for installing each stud in advance, and is then welded using a stud welding method. It is fixed directly to the boiler tube or by welding to the tip -L of the worn stud on the boiler tube, and each stud is installed by coating the head of the stud in the hole with a ceramic material C similar to the above-mentioned refractory material and coating it with a refractory material layer. so that a layer of refractory material can be formed simultaneously with the welding of the stud to the boiler dupe or over the tip of a worn stud on the boiler dupe, resulting in a boiler dupe construction or repair operation. can be greatly simplified, and a significant reduction in work cost 1- can be expected.

[Brief explanation of drawings]

FIG. 1 is a perspective view schematically showing an embodiment of the method according to the invention, FIG. 2 is a partial sectional view of the embodiment of FIG. 1, and FIG. 3 shows the structure of the refractory material forming the refractory layer. FIG. 4 is a partial sectional view schematically showing another embodiment of the method according to the invention, and FIG. 5 is a J sectional view showing a modification of the refractory material. In the figure, 1: Boiler tube 1.2: Refractory material, 2a:
Stud mounting hole, 3: Stud, 4: Ceramic material.

Claims (1)

[Claims] The studs are passed through each pre-prepared stud mounting hole in the refractory material made of ceramic material and fixed by stud welding either directly to the boiler tube or on the tip of the worn stud on the boiler tube. A method for constructing or repairing a boiler tube, comprising filling and coating the head of a stud in a stud mounting hole with a ceramic material similar to the refractory material described above to form a layer of refractory material.