JPH0886391A - Laminated bent pipe - Google Patents

Abstract

PURPOSE: To coat a bent pipe body with a material excellent in heat resistance and also facilitate the coating method. CONSTITUTION: A metallic wire coil 21 is used as a coated layer 20 installed on the outer side of a bent pipe body 10. The metallic wire coil 21 can be bent freely, and close-fitted easily on the outside of the bent pipe body 10. Then clearances between the metallic wire coil 21 are filled by spray coating 22 so as to maintain leakage resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated bend pipe for use in a curved pipe portion of a transportation pipeline for a fluid such as air.

[0002]

2. Description of the Related Art In recent years, attention has been paid to the fluid transportation of solid materials such as coal. This is for transporting a solid substance by the thrust of a fluid such as air. In the transportation pipeline, the curved pipe portion where the solid substance collides violently wears severely, and a countermeasure against the wear is demanded.

In response to such a demand, the applicant of the present invention has built up a wear-resistant metal on the outer surface of at least the outside of the curved portion of the base material pipe, and covers the entire periphery of the base material pipe so as to cover the built-up layer. A wear resistant bend pipe coated with reinforced plastic was developed (Patent No. 1417263).

According to Japanese Patent Application No. 5-192865,
A metal coil bent in a predetermined shape is used as a base material tube, at least the outer peripheral surface of the outside of the curved portion is coated with a wear-resistant material, the coating layer is covered, and the metal wire coil is coated with reinforced plastic around it. An abradable bend tube was proposed.

In these wear-resistant bend pipes, the reinforced plastic plays a role of holding the wear-resistant metal when the base pipe is worn and maintaining airtightness.

[0006]

These wear-resistant bend pipes developed by the present applicant have attracted attention in various fields as extending the life of the curved pipe portion of a fluid passage pipe containing a wear powder. On the other hand, the weakness of the outermost coating layer made of reinforced plastic has become a problem.

[0007] The reinforced plastic coated on the outer surface of the wear-resistant metal, which is built up by welding, casting, etc., is at most 100 to 1
It has only a heat resistance of about 20 ° C. and has a drawback that it cannot be used for high temperature applications. Above 120 ° C., the reinforced plastic is ashed and the abrasion resistant metal cannot be prevented from peeling off.

In order to secure heat resistance, it is conceivable to doubly attach a heat resistant bend pipe to the outer peripheral side of the bend pipe instead of the reinforced plastic. However, the bend pipe on the outer peripheral side needs to be vertically divided into two and welded to each other, which increases the number of manufacturing steps and the manufacturing cost.

It is an object of the present invention to provide a laminated bend pipe in which the outermost coating layer has excellent heat resistance and which can be easily coated.

[0010]

A laminated bend tube of the present invention comprises a bend tube body and a metal wire coil fitted on the outer surface side of the bend tube body and having adjacent metal wires metallurgically connected to each other. To have.

The laminated bend pipe according to the second aspect uses thermal spraying as a means for metallurgically connecting adjacent metal wires of the metal wire coil.

In the laminated bend pipe according to a third aspect of the present invention, the metal wire coil is doubled or tripled or more so that the metal wire of another coil fits between the adjacent metal wire gaps on the outside of the curved portion. It is provided.

A laminated bend pipe according to a fourth aspect of the present invention is a wear-resistant bend body in which a metal wire coil curved in a predetermined shape is coated with a wear-resistant material on at least an outer peripheral surface of the bend portion as a bend pipe body. It uses a tube.

[0014]

In the laminated bend pipe of the present invention, the bend pipe body is covered with the metal coil. Due to its flexibility, the metal wire coil can be easily mounted on the outer surface side of the bend tube body. Since the wires of the metal wire coil are metallurgically connected, the coating layer has excellent heat resistance and leak resistance.

[0015]

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

The laminated bend pipe of FIG. 1 is a bend pipe body 1
0 and a coating layer 20 covering the outer peripheral surface thereof.

The bend pipe main body 10 here uses a metal coil 11 curved into a predetermined shape. Metal coil 1
The outer peripheral surface of 1 is coated with a wear resistant material layer 12.
Further, flanges 13 and 13 are attached to both ends of the metal coil 11.

Such a bend pipe 10 includes a metal coil 1
1 is held in a predetermined curved shape, and in this state, the metal coil 1
It can be manufactured by overlaying a wear resistant metal material on the outer peripheral surface of No. 1 and is easy to manufacture. Further, when the fluid containing the abrasion-resistant powder flows through the inside of the bend pipe 10, the abrasion-resistant material layer 12 suppresses the erosion due to the fluid, and thus exhibits excellent abrasion resistance.

A coating layer 2 for covering the outer peripheral surface of the bend pipe body 10.
0 uses the metal wire coil 21 similarly to the bend pipe main body 10. The metal wire coil 21 is curved along the shape of the bend pipe main body 10, and the adjacent metal wires are filled with a spray coating 22 and metallurgically connected by a bridge.

As is well known, the metal wire coil 21 is a spirally wound metal wire having a certain diameter. Therefore, it is possible to bend freely, and the present inventor has focused on this flexible workability.

In the laminated bend tube of the present invention, the metal wire coil 2 having an inner diameter larger than the outermost diameter of the bend tube body 10 is used.
1 is prepared and this metal wire coil 21 is inserted into the outside of the bend pipe body 10 to cover the entire circumference of the bend pipe body 10. Since the metal wire coil 21 has flexibility, it can be easily inserted into the bend pipe body 10 having any shape and curvature.

When the metal wire coil 21 is in a straight line state, the metal wires forming the coil are in contact with each other and no gap is formed. Once this is bent, a gap is formed outside the curved portion, and the smaller the curvature of the bend pipe body, the larger the gap. On the other hand, on the inside of the curved portion, on the contrary, the lines overlap each other. This is because when the metal wire coil 21 is bent, the outside extends.
This is due to the difference in elongation between the outside and the inside.

If a gap is formed between the metal wires, and if a wear hole is formed in the bend pipe main body 10, the transport medium is ejected to the outside, so it is necessary to fill this gap by some method to integrate it. In the case of a bend pipe with a very large radius of curvature, the difference in length between the outside and the inside is small, so the gap between metal wires is also small, and the gap can be easily adhered by welding or thermal spraying. It is best to use thermal spraying as in 1. The reason is that the construction time is short, the cost is low as a result, and the method is not to melt the metal wire itself but to spray molten metal, so the surface of the wire is sprayed from a microstructural point of view. Although the material is partially melted by the collision energy of the material, it is extremely slight and does not give high energy like that of welding, so that deformation due to welding does not occur.

The thermal spray material includes wire rods, powders, rods, etc.
A maximum thickness of about 2 mm can be obtained by applying heat to these materials with a plasma jet gas combustion flame or the like, melting and accelerating them to form liquid fine particles, and colliding them with the material surface at a high speed. There is also a plasma powder build-up method, but this method melts the spring and therefore there is a risk of deformation. Further, if an adhesive having excellent heat resistance is developed in the future, it may be used.

In any case, a method of spraying a liquid metal and coating and laminating a metal wire without melting, and a method of welding and integrating the metal wires are suitable.

When the distance between the metal wires becomes large, bridging becomes impossible by thermal spraying. In such a case, the double winding method of the spring is the best as shown in FIG.

The thickness of the metal wire may be different between the first layer and the second layer. The method of embedding a second layer in the distance between the wire rods generated in the first layer is the best, and the cross-sectional shape of the wire is good. After performing the double winding, the gap is completely eliminated and the thermal spraying is performed. Although the outer surface of the bend pipe manufactured in this manner is uneven, it does not cause any trouble in use. Rather, since the double-wound coil is uneven, the anchoring effect of the thermal spray material is exerted and the thermal spray strength is increased.

In addition, the method of utilizing the metal wire coil type outer circumference coated bend pipe is very effective when manufacturing a high temperature bend pipe using a ceramic material. Ceramic materials are overwhelmingly superior in erosion resistance, and it is necessary to consider measures for fracture at high temperatures rather than considering wear.

As a bend pipe made of ceramics, it is usually found that the outer peripheral side is made of an iron pipe and the ceramics is inserted inside. There are two types of ceramic pipes, one is manufactured by inserting a large number of short length products, and the other is a united product in which an iron pipe is coated on the outside. In high temperature use,
Since the linear expansion coefficients of the materials are different from each other, the ceramics will break when subjected to thermal shock. When materials having different linear expansion coefficients are integrated and used at a high temperature, a material having poor ductility causes fracture. Therefore, if a method of inserting a ceramics bend pipe between a pair of metal wire coils and not fixing them so that they can be freely deformed, breakage of the ceramics can be prevented.

[0030]

As is apparent from the above description, in the laminated bend pipe of the present invention, the metal wire coil is fitted on the outside of the bend pipe body and the gap is metallurgically connected. Excellent heat resistance and leak resistance, and easy to manufacture. Therefore, it is possible to obtain a great benefit by applying it to a pipe for a fluid transportation pipeline or the like.

In the laminated bend pipe according to the second aspect, the metal wires are metallurgically connected by thermal spraying, and the work is easier than general welding such as welding.

In the laminated bend pipe according to a third aspect of the present invention, by winding the metal wire coil in a double or triple layer, the metal wire gap generated outside the curved portion of the bend tube is made small, and the metallurgy between the metal wires is increased. Makes the physical connection much easier.

In the laminated bend pipe according to the fourth aspect, the bend pipe main body has excellent wear resistance. Moreover, since a metal coil is used for the bend pipe main body, the bending work of the bend pipe main body can be extremely easily performed regardless of the bending shape. Therefore, even a complicated shape can be manufactured quickly and at low cost.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a bend pipe of the present invention.

FIG. 2 is a cross-sectional view showing another example of the bend pipe of the present invention.

[Explanation of symbols]

 10 Bend pipe main body 11 Metal coil 12 Wear resistant material 20 Coating layer 21 Metal wire coil 22 Thermal spray coating

Claims (4)

[Claims] 1. A laminated bend pipe, comprising: a bend pipe main body; and a metal wire coil fitted on the outer surface side of the bend pipe main body and having adjacent metal wires metallurgically connected to each other. 2. The laminated bend pipe according to claim 1, wherein the means for metallurgically connecting the adjacent metal wires of the metal wire coil to each other is thermal spraying. 3. The metal wire coil is provided in double or triple or more so that a metal wire of another coil fits in a gap between adjacent metal wires outside the curved portion. The laminated bend pipe according to claim 1. 4. The bend pipe main body is a wear-resistant bend pipe in which a wear-resistant material is coated on at least the outer peripheral surface of a metal wire coil curved in a predetermined shape on the outer side of the curved portion. The laminated bend tube according to 1, 2, or 3.