JPH0730883B2 - Boiler tube construction or repair method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for constructing or collecting a boiler tube.

[Prior Art] For example, in a boiler tube of a paper mill or the like, generally, a large number of studs are welded along at least a part of the outer periphery in order to enhance protection against corrosion and a heat insulating effect, and these studs form a refractory material layer. I support you. The refractory material layer is usually formed by spraying or applying a mixture of a refractory material and a binder onto a boiler tube having a large number of studs.

The refractory material layer and a large number of studs supporting the refractory material layer differ depending on the usage conditions of the boiler tube, but normally, the tip of the stud is tapered along with the abrasion of the refractory material layer in about 3 to 5 years. Actually, even in the same boiler tube, the abrasion states of the refractory material layer and the stud vary. Therefore, it is necessary to regularly inspect and perform necessary collection. The conventional repair method is to remove the refractory layer and surface deposits, and then cut the studs that need to be repaired out of the studs implanted around the boiler tube to a flat surface from the base or at a predetermined height. Then, a method is known in which a repairing stud is welded to the cut surface by a stud welding method or manual welding, and a refractory layer is applied to the portion by the above method. In such a repair method, it is necessary to cut the burned studs one by one, which requires a lot of labor and time for repair and is not efficient. In order to save labor and time in such repair, a method for repairing a worn stud without cutting it is disclosed in JP-A-59-189078 and JP-A-59-189078.
It is proposed in Japanese Patent Publication No. 59-195002.

[Problems to be Solved by the Invention] By the way, when constructing or repairing a boiler tube used in a paper mill or the like, work in a relatively narrow space which is substantially closed is strong. Therefore, even if the conventional method as disclosed in the above-mentioned publication is used, the number of studs to be implanted is very large, which is a very painful work for the operator, and the construction of the boiler tube is required. As mentioned above, repair and repair work involves not only welding studs, but also forming refractory layers and repair work.
Since this refractory layer is formed and repaired by spraying or coating as described above, it takes time and labor, and the atmosphere becomes extremely bad due to dust, etc. Is physically and psychologically difficult. As a result, even if the method disclosed in the above-mentioned publication is used, the construction and repair of the boiler tube are still troublesome, time consuming and considerably expensive.

Therefore, an object of the present invention is to reduce the number of studs to be implanted around the boiler tube in order to solve the above-mentioned drawbacks of the conventional method, and at the same time as welding the studs to the boiler tube, a refractory material is required. It is to provide a method for constructing or repairing a boiler tube capable of forming layers.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the method for constructing or repairing a boiler tube according to the present invention is such that the boiler tube is integrally attached to the stud and expanded on the side opposite to the weld end of the stud. Then, a stud having a dish-shaped flange whose diameter of maximum expansion is set to be slightly larger than the diameter of each cylindrical stud mounting hole provided in advance in the refractory material made of a ceramic material is attached to each stud of the refractory material. Use the stud welding method through the holes for fixing to the boiler tube directly or by welding and fixing on the tip of the burned stud on the boiler tube.The head of the stud in each stud mounting hole is made of ceramic material similar to the above refractory material. It is characterized by filling and coating to form a refractory layer.

[Operation] In the method for constructing or repairing the boiler tube according to the present invention, the refractory material forming the refractory material layer can be attached while welding the stud to the boiler tube. The refractory material to be attached to the boiler tube is preferably formed in the shape of a rectangular plate of fixed size and provided with the required number of stud mounting holes. Therefore, not only when constructing the boiler tube but also when repairing it, the work can be performed relatively easily in a short time. For example, when repairing a boiler tube, weld the repair stud directly onto the worn stud by removing the part of the refractory layer that has worn out and needs repair, or remove the part of the refractory layer that has worn out if necessary. The required size of repair refractory material can be installed.

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

1 and 2 show an embodiment of a method for constructing a boiler tube according to the present invention, 1 is a boiler tube, and a rectangular plate-like refractory material 2 made of a ceramic material is provided for each of these boiler tubes 1. The stud 3 is attached to the boiler tube 1 by welding the stud 3 to the boiler tube 1 through a stud mounting hole 2a provided in the plate-shaped refractory material 2. 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, the dish-shaped brim 3a fixedly attached to the head of each stud 3 is a stud. It is made to sink in the mounting hole 2a,
A ceramic material 4 similar to the refractory material 2 is filled in the recesses on the dish-shaped collar 3a of each welded stud 3.
The dish-shaped collar 3a of each stud 3 acts as a support member for supporting the ceramic material 4. Further, the rectangular plate-shaped refractory material 2 used has a step portion 2b at the peripheral edge as shown in FIG. 3, and the step portion 2b of the adjacent plate-shaped refractory material 2 is overlapped and continuously fire-resistant. A material layer is formed.

FIG. 4 shows an embodiment of a method for repairing a boiler tube according to the present invention. On the left side of the figure, a burned stud 6 is shown, and the tip of this stud 6 is rounded and tapered. . As shown on the right side of the figure, a repairing stud 7 having a dish-shaped brim 7a fixedly attached to the head is directly welded on the abraded rounded and tapered tip portion, whereby the FIG. Further, a repairing plate-like refractory material 8 which can be made of a ceramic material similar to the refractory material 2 shown in FIG. 2 is supported through its stud mounting holes 8a. Then, a filling material 9 made of a ceramic material similar to the plate-shaped refractory material 8 for repair is filled in the upper portion of the stud mounting hole 8a.

Further, in the illustrated embodiment, a plate-shaped refractory material is used, but if necessary, a block-shaped or curved shape can be used.

[Effects of the Invention] As described above, according to the method of the present invention, the stud is passed through the respective stud mounting holes provided in advance in the refractory material made of the ceramic material, and the boiler tube is formed by the stud welding method. Directly on the stud or on the tip of a worn stud on the boiler tube, and fill the stud head in each stud mounting hole with a ceramic material similar to the above refractory material to form a refractory material layer. Since the stud is welded to the stud boiler tube or onto the tip of a worn stud on the boiler tube, the refractory layer can be formed at the same time, resulting in significant boiler tube construction or repair work. It can be simplified and the work cost can be greatly reduced.

[Brief description of drawings]

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

Claims (1)

[Claims] 1. A cylindrical stud mounting hole, which is integrally attached to a stud, expands to a side opposite to a weld end of the stud, and the maximum expanded part is provided in advance in a refractory material made of a ceramic material. The studs with a dish-shaped collar that is slightly larger than the diameter of the above, through the stud mounting holes of the refractory material directly on the boiler tube by the stud welding method or on the tip of the burned stud on the boiler tube. A method for constructing or repairing a boiler tube, which comprises fixing by welding and filling the head of the stud in each stud mounting hole with a ceramic material similar to the above-mentioned refractory material to form a refractory material layer.