JPS6149367B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an underwater heat treatment device for underwater heat treatment of welded parts of structures to be welded underwater.Generally, welded structures are treated with residual stress to improve the quality of welded joints depending on the purpose of use. A heat treatment is applied to remove such substances. On the other hand, in recent years, marine development has advanced and various underwater structures have been constructed, increasing the need for underwater repairs due to accidents and corrosion due to aging. When such structures are welded underwater, problems such as the welding part becoming hardened and lacking in ductility arise because the welded part is rapidly cooled by the surrounding water. Therefore, even in water, heat treatment such as annealing was necessary to improve the quality after welding.

However, when heat treating a cylindrical structure,
Even if a conventional land-based induction heating device is used, which heats the object 01 by wrapping a heating cable 03 around the outer periphery of the object 01 via a heat insulating material 02, as shown in FIG. Due to poor adhesion of the heat insulating material 02, water penetrates into the heated part and the object to be heated 01 comes into direct contact with the surrounding water, causing convection of the surrounding water and the cooling effect of the water causing enormous heat loss and the temperature rising itself. There was a drawback that it was difficult to heat-treat the object to be heated. In addition, if equipment is used that works with the area around the welded area surrounded by a special container to exclude the water inside, it is possible to use the equipment used on land as is, but the equipment costs will increase enormously. It had the following drawbacks.

Therefore, the device of the present invention prevents water from penetrating between the induction heating cable and the object by closely adhering a heat-resistant insulation material to the outer circumferential surface of the object to be heated, thereby achieving large heating even with a simple induction heating mechanism. The structure of the apparatus of the present invention to achieve this object is a heat treatment apparatus that heat-treats the object by applying electricity to a coil wound around the object. An insulating case surrounding the object is formed to be splittable in the axial direction, and a coil is stored in each divided insulating case, while a terminal is provided on the joint surface of the above insulating case to interconnect with the other coil, and further pressure is applied. A pressurized gas bag that expands toward the heated object by supplying gas is provided on the heated object side circumferential surface of the heat insulation case, and a sealing material is further provided on the heated object side circumferential surface of the pressurized gas bag. The present invention is characterized in that a filling bag is provided, a heat-resistant heat insulating material is housed inside the sealing material filling bag, and a small hole is provided on the circumferential surface of the bag.

An embodiment of the apparatus of the present invention will be described in detail below with reference to the drawings.

As shown in FIGS. 2 and 3, in the apparatus of the present invention, a cylindrical heat insulating case 17 surrounding a cylindrical structure, which is an object to be heated 1, is divided in the axial direction to form a semi-cylindrical shape, and each of the divided The heat insulating case 17 houses a heating cable 3 that forms a coil, and the ends of the heat insulating cases 17 that are joined to each other, that is, the joint surfaces, are connected to the heating cable 3 housed in the other heat insulating case 17 to form a coil. Terminals 4a, 4b to be formed
to protrude. On the other hand, a pressurized gas bag 12 that expands toward the heated object 1 by supplying pressurized gas 11a to the circumferential surface of the heat insulating case 17 on the side of the heated object 1
In addition, a heat-resistant heat insulating material 6a is housed inside the pressurized gas bag 12 on the side of the heated object 1, and a large number of small holes 7 are formed on the circumferential surface to be crimped onto the heated object 1.
It has a structure in which a sealing material filling bag 8 with a sealing material filling bag 8 is provided in close contact with each other.

The heating cable 3 has a conductor 3a as shown in FIG.
Its outer periphery is covered with a covering material 3b, and it is provided with a male terminal 4a and a female terminal 4b at both ends, and is encapsulated in the flexible material 16a filled in the heat insulating case 17, and is housed in the heat insulating case 17 in a layered manner. . The male terminal 4a and the female terminal 4b are disposed corresponding to the joining surfaces of both the insulation cases 17, and when both the insulation cases 17 are joined together, they are connected to each other via the respective terminals 4a and 4b to form a coil. do. Further, on the flat surface of the heat insulating case 17, lead terminals 5a and 5b are provided for supplying electricity to the coil from an external power source.

Next, the pressurized gas bag 12 is formed into a semi-cylindrical shape so as to adhere to the semi-cylindrical peripheral surface of the heat insulating case 17, and pressurized gas 11a is supplied to inflate the pressurized gas bag 12. A gas inlet 14 is provided on the flat surface for the purpose. Further, the pressurized gas bag 12 is formed in two layers with an outer wall 13 and an inner wall 15, and the outer wall 1
3 is made of a flexible heat insulating material, and the inner wall 15 is made of heat-resistant rubber.

Similarly, the sealing material filling bag 8 is formed in a semi-cylindrical shape so as to adhere to the semi-cylindrical circumferential surface of the pressurized gas bag 12, and when pressed by the expanded pressurized gas bag 12, the inside A large number of small holes 7 are provided on the circumferential surface of the sealing material filling bag 8 on the side of the heated object 1 through which the heat-resistant heat insulating material 6a stored in the sealing material filling bag 8 leaks to the outer circumferential surface of the heated object 1.
Further, the sealing material filling bag 8 is also formed in double layers with an outer wall 9 and an inner wall 10, the outer wall 9 being made of a flexible heat insulating material, and the inner wall 10 being made of a stretchable material such as rubber or vinyl. . The above-mentioned heat insulating material is used to protect the above-mentioned elastic material from burnout, and is preferably made of asbestos, ceramic fiber, etc. However, if used as is, it will absorb moisture and cause heat loss, so the surface should be coated with aluminum vapor deposition, etc. Good to use. Further, the heat-resistant heat insulating material 6a has viscosity at room temperature and solidifies in water, and is preferably an underwater-setting heat-resistant paint, cement, or the like.

The thus divided semi-cylindrical heat insulating case 17, pressurized gas bag 12, and sealing material filling bag 8 are fixed to each other and integrated into a divided unit 20a.
form. Furthermore, a tightening band 19 shown in FIG. 6 is used to join the corresponding pair of divided units 20a, 20b and fix them to the object to be heated 1.

Next, the operation of the underwater heat treatment apparatus having the above structure will be explained.

When performing heat treatment in water using the apparatus of the present invention,
A set of divided units 20 divided into two semi-cylindrical shapes
The divided units 20a and 20b are joined together using the parts a and 20b so as to surround the cylindrical object to be heated 1. In this case, the male terminal 4a is fitted into the corresponding female terminal 4b, the heating cables 3 are connected to each other, and a heating coil is formed. A tightening band 19 is attached to the outer periphery of the joined split units 20a and 20b.
is wound, and both divided units 20a and 20b are tightened together and fixed to the object to be heated 1 at the same time. Next, when pressurized gas 11a is fed into the pressurized gas bag 12 from above the water through the gas intake port 14, the pressurized gas bag 12 is expanded by the fed pressurized gas 11a, and the sealing material filling bag 8 is covered. Press evenly towards heating object 1.
Due to the expansion of the pressurized gas bag 12, the sealing material filling bag 8
is in close contact with the outer periphery of the object to be heated 1, and at the same time, the heat-resistant heat insulating material 6a stored in the sealing material filling bag 8 is inserted into the small hole 7.
The heated object 1 is leaked to the outer peripheral surface of the heated object 1.
The space between the outer peripheral surface of the sealing material filling bag 8 and the peripheral surface of the heated object 1 side of the sealing material filling bag 8 is filled without any gap. Therefore, even if the heating coil is energized and the heated object 1 is heat-treated, the heated object 1
Since the outer peripheral surface of is covered with the heat-resistant heat insulating material 6a, it does not come into direct contact with water, so that heat loss due to water convection can be suppressed to a minimum.

In the above embodiments, a cylindrical object to be heated has been described as an object to which the apparatus of the present invention can be applied. It can be used for various structures by forming it. For example, when heat treating a prismatic structure, as shown in Fig. 6, the main body of the device, which has a rectangular cross section, is divided into two parts in the axial direction, and a detachable dividing unit 2 is used.
0a and 20b, and a sealing material filling bag 8 that is press-fitted to the outer peripheral surface of the prismatic object to be heated 1; and a pressurized gas bag 12 that covers the outer periphery of the sealing material filling bag 8;
It is provided with a heat insulating case 17 that covers the outer periphery of the pressurized gas bag 12 and houses the heating cable 3 in a coil shape. In this case as well, the corresponding male terminal 4a and female terminal 4 of the heating cable 3 are treated similarly to the heat treatment of the cylindrical structure described above.
If the pressurized gas 11a is supplied to the pressurized gas bag 15 by connecting the split units 20a and 20b with the tightening band 19 from the periphery, the same effect as in the above embodiment can be obtained.

Furthermore, although the divided unit is divided into two parts in the above embodiment, it may be divided into any number of parts depending on the purpose of transportation and use.

Next, the experimental effects will be explained.

Figure 7 shows the results of heat treatment performed in water with a constant current. Compared to case a when a conventional induction heating device was directly brought into the water and heated, case b when heated underwater using the device of the present invention was able to obtain about twice the temperature rise of the heated object, as shown in Figure 7. , a is the temperature increase characteristic in water using a conventional induction heating device,
b is the temperature increase characteristic using the underwater heat treatment apparatus of the present invention.

As specifically explained above in conjunction with the embodiments, the underwater heat treatment apparatus of the present invention covers the outer circumferential surface of the object to be heated with a heat-resistant insulation material, and allows water to penetrate into the object in order to heat the object in close contact with the heating cable. Since there is no convection caused by surrounding water, the cooling effect of water can be prevented and heat loss in the heating section can be suppressed. Furthermore, the heat treatment equipment is also smaller than before, and equipment costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing an outline of a conventional induction heating method, FIG. 2 is a perspective view showing a divided unit of the heat treatment apparatus of the present invention, FIG. Figure 5 is a central vertical sectional view of the heating cable unit, Figure 5 is an overview of the tightening band, Figure 6 is a cross sectional view of the heat treatment equipment for heat treating a prismatic structure, and Figure 7
The figure is a graph showing temperature increase characteristics. In the drawings, 01 is the object to be heated, 02 is the heat insulating material, 0
3, 3 is a heating cable, 3a is a conductor, 3b is a covering material, 4a is a male terminal, 4b is a female terminal, 5a, 5b is an extraction terminal, 6a is a heat-resistant insulation material, 7 is a small hole, 8
11a is a sealing material filling bag, 11a is a pressurized gas, 12 is a pressurized gas bag, 14 is a gas intake port, 16a is a flexible material, 17 is a heat insulating case, 19 is a tightening band, 2
0a and 20b are divided units, a is the temperature increase characteristic of the conventional induction heating apparatus in water, and b is the temperature rise characteristic of the underwater heat treatment apparatus of the present invention.

Claims (1)

[Claims] 1. In a heat treatment apparatus that heat-treats an object by applying electricity to a coil wound around the object, an insulating case surrounding the object to be heated is formed so as to be splittable in the axial direction, and a coil is attached to each divided insulating case. On the other hand, a terminal is provided on the joint surface of the insulating case to connect it with the other coil, and a pressurized gas bag that expands toward the object to be heated by supplying pressurized gas is installed in the insulating case. Further, a sealing material filling bag is provided on the heating object side circumferential surface of the pressurized gas bag, and a heat-resistant heat insulating material is stored inside the sealing material filling bag, and a heat insulating material is stored in the sealing material filling bag. An underwater heat treatment device characterized by having small holes in its surface.