JPH0692023B2 - Manufacturing method of composite structure pipe with branch pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is applicable to parts requiring branching in gas-liquid transportation (including solid mixed fluid) piping materials that require heat resistance, corrosion resistance and wear resistance of ceramics. The present invention relates to a method for manufacturing a composite structure pipe with a branch pipe used.

(Prior Art) In a composite structure tube or a composite structure T-shaped tube in which a ceramic layer is formed on the inner surface of a mother tube (exterior tube), the ceramic layer exhibits excellent characteristics such as heat resistance, wear resistance, and corrosion resistance. Therefore, it has a wide range of applications as a transport pipe for various fluids and an industrial piping member.

In the above case, as a manufacturing means for the structural tube and the T-shaped tube, a means for sticking and fixing the sintered ceramics on the entire inner peripheral surface of the mother tube through an adhesive, or a core set in the mother tube to form the mother tube Casting means for casting molten ceramics in the gap of the core, or a so-called centrifugal thermite utilizing centrifugal force and thermite reaction, as in the inventions described in JP-A-50-114408 and JP-A-51-107307. The law is known.

(Problems to be Solved by the Invention) In the above-mentioned conventional technique, in the case of a composite structure T-shaped pipe in which the mother pipe is composed of a straight pipe and a branch pipe, the shape thereof is From the characteristics, simply using conventional technology,
The following problems arise.

First, the means for adhering the sintered ceramics with an adhesive will be explained. Separately, a branch pipe and a straight pipe with a branch diameter hole formed in a part of the pipe wall are separately prepared, and an adhesive is applied to the inner peripheral surfaces of both pipes. Then, the sintered ceramics are attached, and then the straight pipe and the branch pipe are joined and fixed in a T-shape. This means that the work is complicated,
There is a drawback that it is difficult to obtain a stable and strong composite state of the mother tube and the sintered ceramics.

Next, the casting method has a drawback that the ceramics layer is considerably thick and that although it is long, it cannot be integrally molded.

Further, the composite T-shaped tube shown in FIGS. 10 and 10 manufactured by the centrifugal thermite method has the following drawbacks.

That is, FIGS. 1 and 2 show cross-sectional views of the T-shaped portion of the mother pipe, in which 1 is a straight pipe of the mother pipe, 2 is a branch pipe of the mother pipe,
3, 3'is a produced ceramic layer, and 4, 4 'is a produced metal layer. In this method, the straight pipe 3 and the branch pipe 4 are separately formed with a ceramic layer on the inner peripheral surface by the centrifugal thermite method, and then the branch pipe is provided in a hole provided in a portion of the straight pipe 1 as shown in FIG. Insert the base end of No. 2 and weld both 5 together, or as shown in Fig. II, saddle-shape the base end of the branch pipe 2 on a hole provided in a part of the pipe wall and weld 5 both to make a T-shaped pipe. Is manufactured,
As shown by reference numerals 6 and 6'in both Figures I and II, the end face of the produced metal layer 4'and the branch pipe 2 remains in the former, and the end face of the hole formed in the produced metal layer 4 and the straight pipe 1 remains as an exposed portion in the latter. Therefore, it is a major drawback in terms of corrosion resistance.

Therefore, in order to solve the above-mentioned problems, it is possible to shield the exposed metal portion as shown in FIG. 11, but when the straight pipe 1 and the branch pipe 2 are welded together, the ceramic layer 3 is cracked, The seams 7 are easily opened, their bonding is very difficult, and the composite material is not easily machined.

(Means for Solving Problems) The present invention is intended to eliminate the drawbacks of the above-mentioned conventional techniques, and the following means have been taken to achieve this object.

That is, the feature of the present invention is a method for producing a composite structure pipe in which a ceramic layer is formed on the inner surface of a mother pipe consisting of a straight pipe and a branch pipe protruding from the outer surface of a portion of the straight pipe wall. A step of fitting a ceramic cylinder into the branch pipe so that the inner end of the ceramic cylinder protrudes inward from the inner surface of the straight pipe; and a step of contacting the inner end protrusion of the ceramic cylinder. A step of forming a thermite agent layer on the inner surface side of the straight pipe, and a thermite reaction of the thermite agent layer,
And a step of forming a ceramics layer on the inner surface of the straight pipe and integrating the ceramics layer with the ceramics cylinder.

(Example) Hereinafter, one suitable example of the manufacturing method of the present invention will be described with reference to the drawings. FIG. 1 is a half sectional view of a main part in a state in which a thermite reaction is caused by rotating a metal frame at a high speed, FIG. 2 is a vertical cross sectional view of the main part, and FIGS. 3 to 7 are manufacturing steps of the present invention. FIG. The steps will be described below in order.

First, the step A will be described with reference to FIGS. 3 and 4. In the drawing, 10 is a straight pipe such as a steel pipe, 11 is also a branch pipe, and the branch pipe 11 has its base end fixed by welding to the outer surface of the hole position opened in a part of the wall of the straight pipe 10. A T-shaped portion is formed, and a mother pipe 12 composed of a straight pipe 10 and a branch pipe 11 is constituted. In the present invention, this mother pipe 12 is used, and the T-shaped portion of the mother pipe 12 is a branch pipe 11.
The plug body 13 is fitted to the inner surface 10a of the straight pipe 12 so as to project therefrom. In this case, the plug 13 has heat resistance and can be crushed and removed relatively easily after lining. For example, the inner plug 14 made of graphite and the ceramic cylindrical body 15 fitted on the inner plug 14 are used.
As shown in detail in FIGS. 1 and 2, the length of the plug 13 is such that the lower end thereof is sufficiently projected from the inner surface 10a of the straight pipe 10 when it is fitted in the branch pipe 11. The lower end surface 13a of the plug 13 is formed in a concave arc shape so as to match the outer diameter of the core described later. The inner plug 14 of the plug 13
Is not limited to graphite. In short, it is important to use a ceramic cylindrical body 15, and further, a material having such a strength that a large residual stress does not remain in the cylindrical body 15 and the ceramic layer formed later. . Also, for example, in the case of the graphite of the previous example, the inner plug 14 should have a low density, or a counterbore portion should be provided in the center of the plug body as shown by the chain double-dashed line in FIG. May be weakened. On the other hand, the ceramic cylindrical body 15 is preferably made of the same material as the ceramic layer to be described later, and it is preferable that the inner plug 14 is externally fitted through a release agent.

Next, step B and step C will be described with reference to FIGS. In the figure, 16 is a cylindrical sleeve whose outer diameter is substantially the same as the inner diameter of a metal frame described later, whose inner diameter is substantially the same as the outer diameter of the straight pipe 10, and which is divided in the radial direction.
As shown in FIG. 2, the dividing surface 16a passes through the axis of the branch pipe 11 and is divided into two. In step B, the sleeve 16 is covered with the plug 13 of FIG. 4 on the mother pipe 12 fitted in the branch pipe 11. However, since the mother pipe 12 is provided with the branch pipe 11, it is natural. Notch 16 at the position corresponding to the branch pipe of sleeve 16
d is provided so that the outer cover is not hindered. The sleeve 16 has a wall thickness larger than the length of the branch pipe 11 as is apparent from the drawing, and graphite is preferable as a material thereof in consideration of heat resistance, mold release, and high thermal conductivity. Although the sleeve has been shown to be divided into two, the number of divisions is not limited, and the sleeve having a thicker wall is used. As shown in FIG. It is possible to use one that is concentrically inserted, and by using this multi-layer sleeve 16b and the branch pipe sleeve 16c corresponding to the diameter of the branch pipe 11, the straight pipe of the mother pipe 12 is used while using one metal frame. This is preferable because it is possible to manufacture T-shaped pipes of various structures in which the pipe 10 and the branch pipe 11 have different diameters.

Next, the step C of filling the inner surface 10a side of the straight pipe 10 of the mother pipe 12 with the thermite agent 18 is, for example, in the case of a large-diameter pipe, using a trough or a screw feeder, that is, rotating spraying, that is, the mother pipe 12 is rotated while the powder agent is rained. Although a small diameter pipe is illustrated in the embodiment of the present invention, a method of filling the thermite agent 18 around the periphery using a core 17 as shown by a chain double-dashed line in FIG. 5 is used. To take.

That is, it is preferable to stand up the mother tube 12 with the sleeve 16 covered and to fill it while applying vibration thereto or sequentially applying tension to obtain a uniform packed state. This state is shown in FIG.

Next, step D of assembling the set body of the mother tube 12 and the sleeve 16 filled with the thermite agent 18 into the metal frame 19 and fixing both ends thereof will be described. As shown in FIG. 6, it is vertically inserted, and with the core 17 inserted, it is inserted into the metal frame 19 as shown in FIG. Prior to this insertion, as shown in FIGS. 1 and 2, the backup member 20 of the plug 13 is fitted in the notch 16d of the sleeve 16, but this is not always necessary. Next core 17
Take out. At this time, since the thermite agent 18 is well stored, it will not collapse even if the core 17 is removed. After that gold frame
Bands 21 and 21 are attached to both ends of 19 and cotter pin 22 is driven in, and the preparation is completed.

Thus, the process E is performed in which the metal frame 19 is rotated at a high speed to cause the thermite reaction. That is, the thermite agent 18 layer is ignited in the centrifugal field to cause the thermite reaction.
For example, 19 is rotated to a predetermined number of revolutions of about 100 to 200 G, and at least one point is raised to the reaction start temperature in that state. Then, the reaction is completed very rapidly over the entire surface in a short time.

After that, after cooling the whole including the metal frame 19, the mother tube 12 and the like are extracted together with the sleeve 16, and the sleeve 16 is removed,
Only the inner plug 14 of the plug 13 is crushed and removed so as not to damage the surrounding ceramic tube 15 and further the generated ceramic layer 24 (step F). As a result, the inner wall surface of the branch pipe 11 is covered with the ceramic tube 15. Will be formed.

The composite T-shaped tube thus obtained is shown in FIG. 9, in which reference numeral 23 denotes a produced metal layer, 24 denotes a produced ceramic layer, and the protruding extra length of the ceramic cylindrical body 15 protruding from the ceramic layer 24. 25 may be removed later by grinding with a diamond grindstone or the like.

In the embodiment of the present invention described above, the steps are A → B → C → D → E.
Although the order is → F, the steps B → C can be performed as C → B. In addition, it goes without saying that the thickness and material of the produced ceramic layer 24 and the ceramic cylinder 15 can be arbitrarily selected according to the purpose of use.

(Effects of the Invention) According to the method of the present invention, it is possible to provide a product that is strong and particularly excellent in corrosion resistance, by preventing exposed metal portions from occurring at the branch pipe joints of the composite pipe with branch pipe manufactured by the centrifugal thermite method. . That is, due to the heat of thermite reaction, the straight pipe and the branch pipe of the mother pipe contract and become smaller than the original size.
A compressive force acts on this, and the boundary between the product, the metal layer and the ceramics layer, is also partially melted, and the integration with the mother tube is strengthened. Particularly, in the method of the present invention, the conventional metal frame can be used as it is, the work is easy, and the production can be performed at low cost.

[Brief description of drawings]

FIG. 1 is a half sectional view of an essential part of the present invention in a state where a thermite reaction is caused by rotating a metal frame at a high speed, FIG. 2 is a sectional view of the essential part of the present invention, and FIGS. 3 to 7 are manufacturing steps of the present invention. FIG. 8 is a cross-sectional view of an essential part of another embodiment of the present invention, FIG. 9 is a cross-sectional view of a T-shaped portion of a T-shaped composite structure obtained by the manufacturing method of the present invention, and FIG. , II are sectional views of the T-shaped portion of the T-shaped tube obtained by the conventional manufacturing method, and FIG. 11 is a sectional view of a comparative example similar to FIG. 10 …… straight pipe, 11 …… branch pipe, 12 …… mother pipe, 13 …… plug body, 14
...... Inner plug, 15 …… Ceramic cylinder, 16 …… Sleeve,
18 ... Thermite agent, 19 ... Gold frame, 23 ... Generated metal layer,
24 …… Generated ceramic layer.

Claims (1)

[Claims] 1. A method for producing a composite structure pipe, in which a ceramic layer is formed on an inner surface of a mother pipe consisting of a straight pipe and a branch pipe projecting from an outer surface of a part of a wall of the straight pipe, wherein the branch pipe is made of ceramics. A step of fitting the tubular body inside to project the inner end of the ceramic tubular body inward from the inner surface of the straight pipe; and a step of contacting the inner end projecting portion of the ceramic tubular body with the inner surface of the straight pipe. A step of forming a thermite agent layer, and a thermite reaction of the thermite agent layer,
And a step of forming a ceramics layer on the inner surface of the straight pipe and integrating the ceramics layer with the ceramics cylinder.