JPS6331507Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a clamp-type radiant heater that is mainly used by being wrapped around the outer circumference of a tubular object to be heated.

For example, when multiple steel pipes are welded together at the installation site, it is necessary to heat an area approximately 50cm wide around the welded area to remove local stress in the pipes after welding. However, in the past, there was no convenient heating device suitable for locally heating a steel pipe at any time, which was extremely inconvenient.

The present invention provides a clamp-type radiant heater that can be easily attached to and detached from the outer periphery of a tubular object to be heated, thereby solving the above-mentioned problems.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In Fig. 1, reference numeral 1 denotes a heated object which is formed into an annular shape by bending an elastic metal plate such as a steel strip having a required width and length, and having a cut 1c in a part that can be opened and closed for inserting and removing the heated object. It is a frame for enclosing objects.
Each end of the frame facing the cut 1c is formed into a tubular ear portion 1a, 1b by folding back a metal plate. By inserting a hairpin-shaped connecting pin 2 between the ears 1a and 1b, the ears 1a and 1b are connected and held so that the cut 1c does not open.

3 is attached to the inner wall surface of the frame 1, and is flexible enough to handle the case where the cut 1c is opened and the frame 1 is deformed from an annular shape to a U-shape without any trouble. It is a padded heater with This pad heater 3 is shown in detail in FIGS. 2 to 4. That is, as shown in FIG.
A plurality of ceramic blocks 4 each having two heating wire insertion holes 4a inside are arranged so that each block 4 is alternated in adjacent rows, and the electric resistance is adjusted perpendicularly to the row of blocks 4. The heating wires 5 are passed through the heating wire insertion holes 4a, and the blocks 4 are sewn together alternately and connected. As shown in FIGS. 3 and 4, each ceramic block 4 has a radiation heating opening 4b communicating with each heat generating wire insertion hole 4a on the heating surface facing the object to be heated 7 of each block 4. 4c respectively. Each of these openings is an outwardly tapered groove.

When the openings 4b are provided in each block 4 as described above, the heating wires 5 are brought into a state directly facing the object to be heated 7 due to the openings 4b, and the object to be heated 7 is radially heated in a good manner. When the block 4 and the object to be heated 7 are in contact with each other, the object to be heated 7 is connected to the block 4.
It is also heated by heat conduction through. In any case, the heating wire 5 is connected to the heating wire insertion hole 4 of the block 4.
It does not protrude outside from a and come into contact with the object to be heated 7.

The pad heater 3 is constructed such that the back surface 4d of each block 4 faces the inner wall surface of the frame body 1, and an appropriate heat insulating material is interposed between each block 4 and the frame body 1 so that the back surface 4d of each block 4 faces the inner wall surface of the frame body 1. It is installed. This installation is
A suitable number of blocks 4 are provided with through holes 4e in advance, and mounting screws are inserted into these through holes and screwed onto the frame 1.

The pad heater 3 attached to the frame 1 as described above
Thus, the clamp type radiant heater 6 of the present invention is constructed. This radiant heater 6 always maintains a nearly annular shape due to the elasticity of the metal plate constituting the frame 1, and as shown in FIG.
1b in the X and Y directions to widen the cut 1c, and then pushing it in the Z direction, it is wound around the required outer circumference of a tubular heated object 7, such as a steel pipe, as shown in FIG. It will be done. Then, close the cut 1c and close the ears 1a, 1 of the frame 1.
The radiant heater 6 is tightly wound around the object to be heated 7 by inserting the connecting pin 2 through b and connecting both ears.

FIG. 6 shows how the heater of the present invention is used, in which two similar radiant heaters 6, 6' are wound side by side around a steel pipe 7' to eliminate welding distortion of the steel pipe as described above. It is something that In the radiant heaters 6 and 6' in this drawing, the built-in heating wires 3 are connected in phase, and each is connected to a heating power control device 9 through three power supply lines 8 and 8' to achieve the required heating. It is now receiving electricity. The input side of the control device 9 is connected to a three-phase commercial power line.

Next, to describe a specific numerical example in the usage mode shown in FIG. A phase alternating current voltage of 85V is applied and a current of 75A is applied to supply approximately 11KW of power, and the total heating power of the two is approximately 22KW to radiantly heat the steel pipe 7' to obtain a heating temperature of approximately 650°C. Welding distortion is removed.

As described above, the clamp-type radiant heater according to the present invention has a frame body for enclosing a heated object made of an approximately annular elastic metal plate having a cut in a part that can be opened and closed for inserting and removing the heated object. The frame body is constructed by attaching a pad heater having a characteristic and is provided with connecting means for mutually connecting both ends facing the cut of the frame body, so that it normally maintains a substantially annular shape by itself and does not open the cut. As a result, it can be easily attached to and detached from the desired outer circumference of the tubular object to be heated. Therefore, when performing local heating of a tubular body such as local stress relief at a welded joint of a steel pipe, it is extremely useful to easily wrap it around the tubular body at any time and place in a good wrapping state. It's convenient.

Further, in the radiant heater according to the present invention, since the heating element is formed of a pad heater, it is possible to completely prevent the heating wire from protruding outside from the heating element. Therefore, even if the heating element is placed in direct contact with the object to be heated, the heating wire and the object to be heated will not come into contact and cause an unexpected accident. In addition, the heating element can be used in direct contact with the object to be heated, and furthermore, an opening for radiation heating that communicates with the heating wire insertion hole is formed on the heating surface of each ceramic block that makes up the pad heater, facing the object to be heated. Therefore, the heating efficiency is also excellent.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a partial plan view of an example of a pad heater used in the invention, Fig. 3 is a perspective view showing an example of a ceramic block for the pad heater, and Fig. 4 is a perspective view showing an example of a ceramic block for the pad heater. The figure is a partial cross-sectional view showing an example of the pad heater, FIG. 5 is an explanatory diagram showing the process of wrapping the radiant heater of the present invention around an object to be heated, and FIG. 6 is a mode of use of the radiant heater of the present invention. It is a perspective view showing an example. DESCRIPTION OF SYMBOLS 1...Frame body for surrounding the object to be heated, 1c...Slit for inserting and removing the object to be heated, 2...Connecting pin, 3...Pad heater, 4...Ceramic block, 4a...Heating wire insertion hole, 4b... Radiant heating opening, 5...Resistance heating wire.

Claims (1)

[Scope of utility model registration request] A frame for enclosing a heated object made of an elastic metal plate formed in a substantially annular shape having a cut in a part that can be opened and closed for entering and removing the heated object, and a connection that interconnects both ends of the frame facing the cut. and a flexible pad heater attached to the inner wall surface of the frame with a heat insulating material interposed therebetween, the pad heater having a plurality of heating wire insertion holes inside and facing the object to be heated. A plurality of ceramic blocks having radiant heating openings communicating with the heating wire insertion holes on the heating surface form a large number of rows, and the blocks are arranged alternately in adjacent rows. A clamp-type radiant heater characterized in that resistance heating wires are passed through the heating wire insertion holes in a direction perpendicular to the heating wires, and the blocks are sewn and connected in an alternating manner.