JPS61142685A - Radiatnt tube type heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a heat treatment furnace, and more particularly to a radiant tube type heater in an electric resistance furnace that uses electric heat as a heating heat source.

(Prior art) Conventionally, this radiant tube type heater 1 has
As shown in FIGS. 13 and 17, it is composed of a radiant tube 2 and a heater 4 housed within the radiant tube 2.

The radiant tube 2 is a protective cover to prevent the heating wire 11 of the heater 4 from coming into direct contact with the workpiece, jig, etc. in the furnace, and is formed of heat-resistant steel into a cylindrical shape with a predetermined inner diameter. is closed, and a mounting flange 3 is formed on the base side. Further, the heater 4 is made up of a plurality of insulators 5 and a plurality of heating wires 11, and the insulator 5 has a flange portion having a diameter D1 slightly smaller than the inner diameter of the radiant tube 2 at the base of a truncated conical connecting portion 6. 7 is formed, and on a predetermined radius r from the center of this flange portion 7, an even number (12 holes are provided in the wooden insulator 5) of insertion holes 8 are provided at predetermined intervals through which the electric heat 1Qll can be inserted. It is your honor. Further, a rectangular connecting recess 9 is provided in the center of the flange portion 7, and a rectangular connecting convex portion 10 that can fit into the connecting recess 9 is stepped at the tip of the connecting portion 6. ing. When the connecting recesses 9 and the connecting protrusions 10 of the plurality of insulators 5 thus formed are fitted together, the even number of insertion holes 8 of each insulator are aligned with each other. A heating wire 11 is inserted through the insertion hole 8 of the insulator 5 connected in this manner. The heating wires 11 are bent into a substantially U-shape that can be inserted into adjacent insertion holes 8, and each heating wire 11 is connected in series via a connecting fitting 12. One end of the heating wire 11 is extended, and a terminal 14 is attached to the same end 13. The heater 4 thus formed is housed within the radiant tube 2 and is placed on the furnace wall so as to protrude into the furnace.

(Problem to be solved) Therefore, when the heater 4 is housed inside the radiant tube 2, the insulator 5
Since the outer diameter D1 of the flange portion 7 of each insulator 5 is formed to be slightly smaller, the arcuate surface of the outer periphery of the lower side of the flange portion 7 of each insulator 5 is as shown in FIGS. 17 and 18. It is in contact with the inner peripheral surface of the radiant tube 2. Therefore, during long-term use, scale, scum G, etc. are generated from the heating wire 11, radiant tube 2, insulator 5, etc., and these scales, scum G, etc. are deposited on the bottom of the inner peripheral surface of the radiant tube 2, and , especially insulator 5
The deposition progresses along the surface of the flange portion 7 at the place where the heating wires 11 come into contact, and it often happens that the heating wires 11 eventually reach a state where they straddle each other. Therefore, when the state progresses to this state, the current changes to this school,
Flowing through the waste G, the heating wire 11 goes over -1-,
It short-circuited and broke, and the radiant tube 2 broke due to the high heat generated at this time, making it unusable as a heater, resulting in a situation where the furnace had to be shut down. When this furnace has stopped its activity, turn off the power, let the temperature inside the furnace drop, remove the heater 4 and radiant tube 2, replace it with a new radian 1~72 and heater 4, and then raise the temperature again. There was a problem in that it took more than 24 hours to start production, and production was stopped during this time, resulting in a considerable loss of time and cost, including the need to replace the heater and radiant tube.

(Means for Solving the Problems) The present invention has been made to solve the above-mentioned conventional problems, and can significantly reduce the progress of accumulation of scale and scum, thereby increasing the durability of heating wires and radiant tubes. The purpose of the heater is to provide a radiant duplex type heater that can increase the heating efficiency, and its gist is to connect a radiant tube with insulators having a plurality of flanges, and to connect a heating wire through the flanges of the insulators. A radiant tube type heater that houses a heater arranged therein, wherein when the heater is housed in the radiant tube, a required space is formed between the bottom of the inner peripheral surface of the radiant tube and the flange part of the insulator. Existing in tube heaters.

(First Embodiment) Next, the first embodiment of the present invention will be explained according to FIGS. It is composed of a heater 4 housed in a tube 2, and an insulator 15 constituting this heater 4 is formed as follows.

This insulator 15 has a 7-run 9 section 17 in a substantially pentagonal shape (regular pentagonal shape, scalene pentagonal shape) that is inscribed in a circle with a smaller diameter D1 than the inner diameter of the radiant chew 12 at the base of the truncated conical connecting portion 16. An even number (12 holes are provided in the insulator 15 in this example) of insertion holes are formed at a predetermined radius r from the center of the seven runte portions 13 at predetermined intervals through which the heating wires 11 can be inserted. 18 is your honor. In addition, a rectangular connecting port 11g119 is recessed in the center of the seven runte portion, and a rectangular connecting convex portion 20 that can fit into the connecting recess 19 is stepped at the tip of the connecting portion 16. There is. When the connecting concave portions 19 and the connecting convex portions 20 of the plurality of insulators 15 formed in this manner are fitted, seven runs 9 of each insulator 15 are formed.
Each month of the portion 17 and the even number of insertion holes 18 are aligned with each other. The insertion hole 1 of the insulator 15 connected in this way
8 is inserted with electric heat 1Q11. This heating wire 11
are bent into a substantially U-shape that can be inserted into adjacent insertion holes 18, and each heating wire 11 is connected in series via a connecting fitting 12.
1 is extended, and a terminal 14 is attached to the same end 13. The heater 4 thus formed is housed within the radiant tube 2 and is attached to protrude into the furnace from the furnace wall.

Next, the operation and effects of this embodiment configured as described above will be explained.

Now, the radiant tube type heater 1 of this example has an insulator 1 having a plurality of flange portions 17 on the radiant tube 2.
A heater 4 is housed in which heating wires 11 are arranged via 7-run 9 parts 17 of 15 series of the same insulators,
The 7-run 9 portion 17 of the insulator 15 is formed into a substantially pentagonal shape, and when the heater 4 is housed in the radiant chew 2, the corner portions 1 on both sides of the side 17a, which will be the lower part of the flange portion 17 of the insulator 15, are formed.
7b is in contact with the inner peripheral surface of the radian 1 tube 2 to form a required space T between the inner peripheral surface bottom 2a and the side 17a of the 7 run 9 section 17. Therefore, in the process of long-term use, the heating wire 11, radian 1 ~ Buyubu 2, b! Scale, debris G, etc. generated from the insulator 15 are deposited on the bottom of the inner circumferential surface of the radiant tube 2 on both side corners 17b of the side 17a (face) which is the lower part of the insulator 15.

is in contact with the inner circumferential surface of Radian 1 to Dicove 2, and a required space T is formed between the inner circumferential surface bottom 2a and the side 17a of 7-run 9 part 17. Insulator 5
It is possible to significantly reduce the progress of the accumulation of scale and dregs by spreading the surface of the 7-run 9 part 7 from the place where they abut, and the durability of the radiant tube type heater can be significantly increased. .

(Second Embodiment) Next, FIGS. 5 to 8 show a second embodiment of the present invention. In this second embodiment, the insulator 2 of the heater 4 is
1, the shape of the 7 runte portion 22 is approximately octagonal (regular octagonal,
The other configuration is the same as that of the first embodiment. Therefore, when the heater 4 constituted by this insulator 21 is housed inside the radiant tube 2, the flange portion 22 of the insulator 21
Both corner portions 22b of the side 22a (the lower part) are in contact with the inner peripheral surface of the radiant tube 2, and the inner peripheral surface bottom portion 2a
and the side 22a of the 7 runte portion 22.
is formed, and the same effect as in the first embodiment is achieved.

In the above-mentioned Embodiment 1.2, the seven runte portions 17.22 of the insulator 15°21 are formed into a substantially pentagonal shape and a substantially octagonal shape. ), approximately heptagonal shape (regular heptagonal shape, scalene heptagonal shape) may be used, the key point is that the lower radiant tube 2 of the flange part
The above effects are achieved by forming a space between the bottom 2a of the inner circumferential surface of the
A flange portion may be formed as shown in FIG. However, the flange portion 24 of the insulator 23 in FIG. 9 has a predetermined diameter D1.
It is formed into a circular shape, and its lower part fl! 11, a substantially horizontal plane part 24a is formed, and a space (2) is formed between the inner peripheral surface bottom part 2a of the radiant tube 2 and the plane part 24a. Note that this flat portion 24a is formed on the arcuate surface 2 as shown by the dotted line in the figure as long as it does not interfere with the insertion hole 18.
4b may be sufficient. Further, the flange portion 26 of the insulator 25 in FIG. 10 is formed in a circular shape with a predetermined diameter D1, and a recess 26a is formed in the lower part of the flange portion 26, and the inner circumferential surface of the radiant tube 2 is formed on both sides of the recess 26a. A lower space is formed between the bottom 2a of the inner peripheral surface of the radiant tube 2 and the recess 26a. The flange portion 28 of the insulator 27 in FIG. 11 is formed into a circular shape with a predetermined diameter D1, and protrusions 28a are provided at predetermined intervals on the outer periphery of the flange portion. Inner peripheral surface bottom 2a of 9-12
A space T is formed between and the recess 26a. Therefore, even in these cases, the same effects as in the first embodiment can be achieved.

The above is an example of forming the flange part of the insulator in various shapes, but as shown in FIG.
is formed along the longitudinal direction of the radiant tube 2, and a heater 4 made of an insulator 5 is housed within the radiant tube 2, thereby forming a space T between the flange portion 7 and the inner circumferential bottom portion 2a. Therefore, even in this case, the same operation and effect as in the first embodiment can be achieved.

(Effects of the Invention) The present invention is a radiant tube type heater in which a radiant tube is housed with a heater in which insulators having a plurality of flanges are connected in series and heating wires are arranged through the flange portions of the insulators. Therefore, when the heater is installed in the radian l tube, by forming a required space between the bottom of the inner circumferential surface of the radiant coil and the flange of the insulator, the insulator is not placed in contact with the insulator as in the conventional case. The radiant duplex can greatly reduce the accumulation of scale, scum, etc. on the surface of the flange part from the point of contact, and can significantly increase the durability of the radiant tube heater. As a type heater, its contribution is extremely large.

[Brief explanation of drawings]

1 to 4G show a first embodiment of the present invention,
Figure 1 is a partial cross-sectional view of a radiant duplex heater.
FIG. 2 is a sectional view taken along the Ir-Tl line in FIG. 1, FIG. 3 is a front view of the insulator, FIG. 4 is a side view of the insulator, and FIGS. 5 to 8 show a second embodiment of the present invention. , Fig. 5 is a front view of the insulator, Fig. 6 is a side view of the insulator, Fig. 7 is a partial sectional view of the radiant tube type heater, Fig. 8 is a sectional view taken along the line ■-■ of Fig. 7, and Fig. 9 is a sectional view of the insulator. Figures 12 to 12 are sectional views showing other ways of forming the space, Figures 13 to 18 are conventional radiant tube type heaters, and Figure 13 is a partially cutaway front view of the radiant tube. , FIG. 14 is a front view of the heater, FIG. -rV line sectional view. 1... Radiant tube type heater 2... Radiant tube 2a... Inner peripheral surface bottom 2b... Projection 4... Heater 5, 15, 21, 23. '25.27...Insulator 7.1
7, 22, 24, 26.28...flange portion 11...
・Heating wire 17a, 22a...side (surface) 24
a...Flat surface (cutting surface) 24b...Circular surface (cutting surface) 2
6a! ! 1st part 26b-11th part 28a...
・Convex part T... Space part Applicant Nimura Koki Co., Ltd. Agent Ben Sokushi Oka 1) Hidehiko Figure 9 111 Figure 10 Figure 12 IIA

Claims (6)

[Claims] (1) A radiant tube type heater in which a heater is housed in which an insulator having a plurality of flanges is connected to a radiant tube and a heating wire is arranged through the flange of the insulator, wherein the radiant tube is connected to the heater. A radiant tube type heater characterized in that, when the heater is housed, a required space is formed between the bottom of the inner peripheral surface of the radiant tube and the flange of the insulator. (2) A patent claim in which the space is formed by forming the flange portion of the insulator into a substantially pentagonal or octagonal shape to form a space between the lower side and the bottom of the inner peripheral surface of the radiant tube. A radiant tube heater according to item 1. (3) The space portion is formed by forming the flange portion of the insulator into a circular shape with a predetermined diameter, and by forming a horizontal or arcuate face on a part of the outer periphery of the flange portion, so that the flange portion of the insulator is formed with a horizontal or arcuate face. The radiant tube type heater according to claim 1, wherein the radiant tube type heater is configured to form a space between the inner peripheral surface and the bottom. (4) The space portion is formed by forming the flange portion of the insulator into a circular shape with a predetermined diameter, and providing a recessed portion on a part of the outer periphery of the flange portion, and abutting the inner peripheral surface of the radiant tube on both sides of the recessed portion. 2. The radiant tube type heater according to claim 1, wherein a space is formed between the concave portion and the bottom of the inner circumferential surface of the radiant tube by forming contacting leg portions. (5) The space portion is formed by forming the flange portion of the insulator into a circular shape with a predetermined diameter, and protruding convex portions that abut the inner peripheral surface of the radiant tube at predetermined intervals on the outer periphery of the flange portion. The radiant tube type heater according to claim 1, wherein a space is formed between the outer peripheral surface of the flange portion between the convex portions and the bottom of the inner peripheral surface of the radiant tube. (6) The space is formed by arranging protrusions along the longitudinal direction of the radiant tube so that flanges of a predetermined diameter can be placed at predetermined intervals on the bottom side of the inner circumferential surface of the radiant tube. The radiant tube type heater according to claim 1, wherein a space is formed between the outer circumference and the bottom of the inner circumferential surface of the radiant tube.