JP3523396B2 - Far infrared heater for heating furnace - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a panel-type far-infrared heater for a heating furnace. And a far-infrared heater for a heating furnace.

[0002]

2. Description of the Related Art Conventionally, in a panel type far-infrared heater, as shown in FIG. 6, a combustion gas supply duct 1 for combustion gas is separately provided on both sides of one end and the other end of a heat radiating portion 4.
2. Exhaust gas return ducts 16 are provided respectively, and these ducts 12, 16 are connected by a pipe forming a gas circulation passage 7, and a circulation blower 6 is provided in the middle of the gas circulation passage 7 pipe. The combustor 1 is attached to the downstream side pipe of the circulation blower 6 of the circulation path 7 to form a combustion space B in the gas circulation path 7, and the combustion gas supply path 7a on the downstream side of the combustion space B is used. The heat radiation plate 4a of the heat radiation portion 4 is heated by the supplied combustion gas. The heat radiating portion 4 is attached inside the heating furnace F, and the partial exhaust portion 10 attached to the exhaust gas return duct 16 is provided.
Through the ceiling wall of the heating furnace F, and the heat radiating portion 4 is attached to the frame of the heating furnace F so as to be drawn out of the furnace.
It was fixed separately from. In the far-infrared heater H, the combustion waste gas returned from the circulation blower 6 and the combustion exhaust gas supplied from the combustor 1 to the combustion space B together with air in the downstream portion of the combustion space B. The mixture is mixed to form a combustion gas for heating and is supplied to the heat radiating section 4 through the combustion gas supply duct 12 attached to the one end side of the heat radiating section 4. The supplied combustion gas is discharged from the exhaust gas return duct 16 attached to the other end while heating the heat dissipation plate 4a of the heat dissipation unit 4 to 400 to 500 ° C. The exhausted combustion exhaust gas is attracted to the circulation blower 6 and is circulated and supplied toward the combustion space B. At the same time, a part of the combustion exhaust gas is exhausted from the partial exhaust part 10 while controlling the emission amount with a regulating valve.

[0003]

However, in the conventional panel type far-infrared heater H described above, the heat radiating portion 4 is provided in the heating furnace F, the other combustor 1, the circulation blower 6, the gas circulation path 7, and Part of the exhaust unit 10 is outside the heating furnace F,
Since it is fixed to the frame of the heating furnace F, the ceiling furnace wall of the heating furnace F is removed and repaired at the time of installation and removal, and there is a problem that large-scale work is required for installation, maintenance, and removal. And the heat dissipation part 4
The flow path of the combustion gas for heating inside is directed to one direction in the longitudinal direction of the heater H, and in the heat dissipation portion 4, the combustion gas is supplied from the combustion gas supply duct 12 attached to one end side. Since the gas is discharged to the exhaust gas return duct 16 attached to the other end side, the temperature of the heat radiating plate 4a of the heat radiating section 4 heated by the combustion gas gradually increases from the one end side to the other end side. A temperature gradient that decreases is generated, it is difficult to uniformly heat the object to be heated below the heat radiating section 4, and the combustion gas flow direction of the heat radiating section 4 is parallel to the moving direction of the object to be heated. It has to be installed, and there is a problem that it is difficult to adjust the temperature distribution in the lateral direction of the far infrared heater H. Therefore, an object of the present invention is to solve the above-mentioned problems, to be easily attached and detached, and to suppress the temperature unevenness generated in the object to be heated due to the temperature distribution of the heat radiation surface during use, In addition, the present invention is to provide a compact far-infrared heater for a heating furnace, which is excellent in fuel efficiency and maintainability.

[0004]

[Effects of feature configuration]

Therefore, according to the above characteristic configuration, while forming a gas circulation path connecting the combustor and the heat radiating unit via the circulating blower, the mounting unit includes the combustor, the heat radiating unit, and the circulating blower. Since the far-infrared heater of the present invention is mounted together and integrally formed, the mounting portion can be formed in the furnace lid of the heating furnace while the waste heat of the combustion exhaust gas can be used and the thermal efficiency can be improved. Since it is done, it is enough to install it in the heating furnace hand hole,
No special work required. As a result, it is possible to provide a far-infrared heater for a heating furnace that is easy to install and remove, is compact, and has excellent repairability and inspection.
Then, the combustion gas path is divided into an outward path and a return path that communicate with each other on the one end side of the heat dissipation section, and a combustion gas supply path for supplying the combustion gas from the combustor to the outward path and a combustion exhaust gas from the return path. And an exhaust gas return path for returning to the combustor, since both are arranged on the other end side of the heat dissipation portion ,
The combustion gas supply passage and the exhaust gas return passage, which are attached to a mounting portion that can configure the furnace lid and are provided outside the furnace, can be integrally heat-insulated, and the far-infrared heater of the present invention is integrated. To make it even easier. Further, if both the combustion gas supply passage and the exhaust gas return passage are arranged on the other end side, it is easy to form a combustion gas passage in the heat dissipation portion in a reciprocating passage, By forming the combustion gas passage in the reciprocating passage, the temperature difference between the one end side and the other end side of the heat radiating portion can be made small. As a result, the far-infrared heater can be made compact, and it is possible to suppress the temperature unevenness that occurs in the object to be heated during its use. [Additional Configuration 1 and Operation and Effect] Further, a plurality of combustion gas paths in the characteristic configuration are provided, and the plurality of the outward paths and the return paths are alternately arranged in parallel and arranged in the heat dissipation section (corresponding to claim 2 ). It is even better if done, and if done in this way, on the one end side,
The communication parts of the forward path and the return path having substantially the same temperature will be arranged continuously, and as a result, the combustion gas supply path and the exhaust gas return path are alternately arranged on the one end side, By the heat flow between the forward path and the return path,
The temperature on the other end side is also averaged and becomes almost the same temperature as the communication part, and it is possible to suppress the occurrence of a temperature gradient as a whole, and it is possible to make the temperature of the heat dissipation surface of the heat dissipation part substantially uniform. Further, by providing a plurality of the combustion gas supply passages and individually supplying the combustion gas for heating to each of the outward passages, the amount of the combustion gas supply from the plurality of combustion gas supply passages to the heat radiation part is adjusted. By doing so, it is possible to suppress the temperature difference between the forward paths, and it is possible to prevent variations in temperature particularly in the direction in which the forward path and the return path are arranged in parallel. As a result, the far-infrared heater can be improved in heating capacity, fuel efficiency can be improved, and the temperature of the heat radiating surface can be made uniform during use of the far infrared heater to suppress temperature unevenness occurring in the object to be heated. [Additional configurations 2 and effects] Then, constitute a double tube structure comprising a combustor definitive on the characteristic configuration or said additional structure 1 from the inner and outer cylinders, the combustion space inside the inner tube Along with forming the outer cylinder and the inner cylinder, an inflow part of the exhaust gas returning from the heat dissipation part is formed, and on the downstream side of the inner cylinder, from the combustion gas from the combustion space and the heat dissipation part. It is better if a mixing space for mixing with the returning exhaust gas is formed (corresponding to claim 3 ). In this case, since the returning exhaust gas is mixed with the combustion gas with residual heat, it is supplied to the heat dissipation portion. The waste of the amount of heat generated can be suppressed, and at the same time, the exhaust gas returning from the inflow portion comes into contact with the inner cylinder at the time of inflow, so that the exhaust gas is easily heated and the temperature unevenness in the mixed gas in the mixing space can be suppressed. Further, the inner cylinder is heated by the internal combustion flame, but is cooled by the exhaust gas, so that extreme heating of the inner cylinder can be prevented and at the same time, the temperature difference inside the inner cylinder can be reduced, It is possible to extend the life of the inner cylinder. Furthermore, as described above, since the exhaust gas is circulated around the inner cylinder that surrounds the combustion space,
The inner cylinder is not in contact with the heat insulating material interposed between the far infrared heater installation space, the heat of the combustion gas does not directly flow out to the installation space, heat loss can be suppressed, and thermal efficiency is improved. Can be improved. As a result, the fuel efficiency of the far-infrared heater can be further improved, and at the same time, the maintainability can be improved especially by extending the life of the inner cylinder. [Additional Configuration 3 and Action and Effect] Further, a suction fan is arranged on the downstream side of the combustor in the characteristic configuration or the additional configuration 1 or 2 to form the circulation blower, and the combustor and the circulation blower are connected to each other. the combustion gas suction path formed of the said combustion gas supply path between the circulation blower and the heat radiating portion is disposed, the exhaust gas return path disposed (claim between the combustor and the heat radiating portion Term
4 )), and by doing so, a gas circulation path can be formed by the exhaust gas return path, the combustion gas suction path, and the combustion gas supply path, and the circulation blower can be formed from the combustion gas suction path. Since the combustion space can be decompressed by sucking the combustion gas by means of, the supply gas in the combustor can be easily combusted and the combustion can be stabilized, and at the same time, a blower for supplying air to the combustor can be provided. Since the capacity can be reduced, the blower can be downsized. As a result, it is possible to provide a far-infrared heater that is compact, improves fuel efficiency, and enables stable operation of the heating furnace.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 5
An embodiment of the present invention is shown in FIG. FIG. 1 illustrates a characteristic configuration of the present invention, FIG. 2 is a plan view of an embodiment of the present invention described below, and FIG. 3 is a III-III line in FIG.
4 is a vertical cross-sectional view as seen in the direction of the arrow in FIG.
-IV is a horizontal sectional view as seen in the direction of the arrow, and FIG. 5 is a vertical sectional view as seen in the direction of the arrow V-V in FIG. The far-infrared heater H for a heating furnace according to the present invention is configured to include a combustor 1 and a heat radiating portion 4 which has a combustion gas passage 5 therein and radiates heat of combustion gas from the combustor 1. Further, a gas circulation path that connects the combustor 1 and the heat dissipation section 4 via a suction fan 6 used as a circulation blower, and further connects the heat dissipation section 4 and the combustor 1 to form a circulation path. 7 is formed, and the combustor 1, the heat radiating portion 4, and the suction fan 6 are attached integrally to the attaching portion 8 (see FIGS. 2, 3, and 5). . Since the mounting portion 8 is formed as described above and is configured to be used also as a furnace lid of the heating furnace, the mounting metal fitting 8a provided in the mounting portion 8 is used for mounting the heater of the heating furnace. The far-infrared heater H can be attached by attaching the attaching portion 8 as a lid to the opening formed in advance. The far-infrared heater H having the above-described structure is used in the heat radiation unit 4
The lower surface (heat dissipation surface) and the mounting bracket 8a of the mounting portion 8 are covered with a heat insulating material 9 made of castable, and the surface thereof is finished with a color steel plate.

The combustor 1 and the suction fan 6 are connected by a combustion gas suction duct 11, and the suction fan 6
Combustion gas and the heat radiating portion 4, the in the combustion gas supply duct 12 to induce combustion gas from the suction fan 6, a combustion gas supply pipe 13 for supplying subjecting the combustion gas to the heat radiating portion 4, between the Yes connected via a distribution header 14, it is connected to the the heat radiation portion 4 and the combustor 1 by exhaust gas return pipe 15. A combustion gas suction passage 7c is formed by the combustion gas suction duct 11, and the combustion gas supply duct 1
2, the combustion gas distribution header 14 and the combustion gas supply pipe 13 form a combustion gas supply passage 7a, and the exhaust gas return pipe 15 forms an exhaust gas return passage 7b. Each of the combustion gas supply pipes 13 is provided with a damper for adjusting the gas flow rate.

The heat radiating portion 4 has a flat rectangular parallelepiped space inside, and a heat radiating plate 4a made of a metal plate is provided on the heat radiating surface.
Inside the rectangular parallelepiped space, from the one end side to the other end side in the vertical direction of the heat radiating plate 4a, a plurality of metal combustion gas paths are formed to separate the rectangular parallelepiped space in the lateral direction of the heat radiating section 4. A partition wall 4b and a reciprocating path partition wall 4c are provided, and a plurality of alternating outward paths 5a and return paths 5b are provided in parallel, and each pair of adjacent outward paths 5a and return paths 5a is provided.
b is communicated with the reciprocating passage partition wall 4c on the one end portion side, and the combustion gas supply pipe 13 for supplying the combustion gas from the combustor 1 is provided on the other end portion side of the outward passage 5a. The exhaust gas return pipe 1 which is connected to the heat dissipation unit 4 and returns the combustion exhaust gas from the combustion gas path 5 to the combustor 1.
5 on the other end side of the return path 5b similarly to the heat dissipation section 4
Connected to. In this way, the combustion gas path 5
Are divided into the forward path 5a and the return path 5b, and a plurality of them are formed so as to reciprocate from the one end side to the other end side. The heat dissipation plate 4a is 400 to 500.
It is heated to about ℃, and its heat dissipation surface is coated with a substance that emits far infrared rays such as ceramics. As described above, since the combustion gas path 5 is formed in the reciprocating path, the temperature difference in the vertical direction is also reduced, and further,
In the case where a single reciprocating combustion gas path is formed, the temperature difference between the outward path 5a and the return path 5b is reduced by the heat conduction of the heat radiating plate 4a, and a plurality of the combustion gas paths 5 are formed. Compared to the forward path 5a and the return path 5b
Can have a narrower width, can suppress the occurrence of temperature distribution in the width direction of the combustion gas passage 5, and can adjust the flow rate of the combustion gas supplied from each combustion gas supply pipe 13 as described above. Since it is configured, the temperature difference in the lateral direction can be reduced. Furthermore, the forward path 5a and the return path 5
Since the flow passage cross-sectional area of b can be made small, the Reynolds number in the flow passage can be made large, and as a result, good heat transfer from the combustion gas flowing in the flow passage to the radiator plate 4a can be achieved. The combustion gas supply path 7a reaches the suction fan 6 from the combustor 1 through the combustion gas suction path 7c, and then the suction fan 6 extends to the combustion gas supply path 7a and the heat dissipation section 4. A gas flow path is formed in the circulation path that reaches the combustor 1 through the combustion gas path 5 and the exhaust gas return path 7b.

The combustor 1 has a double-cylinder structure composed of an inner cylinder 2 and an outer cylinder 3. One end of the inner cylinder 2 is attached to a side wall of one end of the combustor 1. The end portion side is opened in the outer cylinder 3, and the burner 1a is attached to the fuel supply port portion provided in the one end portion side wall portion. Burner 1
Fuel gas and air are supplied from a to form a combustion space B inside the inner cylinder 2, the fuel gas is burned in the combustion space B, and combustion is performed from the other end side of the inner cylinder 2. It is designed to release gas. An inflow portion 3a having a plurality of openings is formed in the outer cylinder 3, an exhaust gas return path 7b is connected to the plurality of openings, and the heat dissipation portion 4 is provided between the outer cylinder 3 and the inner cylinder 2. The exhaust gas returning from the inner space is recirculated, and the combustion space B is provided downstream of the other end of the inner cylinder 2.
A mixing space M for mixing the combustion gas from the exhaust gas and the exhaust gas returning from the heat radiating portion 4 through the exhaust gas return passage 7b is formed. In the mixing space M, the combustion gas and the exhaust gas are mixed so as to be diluted, and the temperature of the diluted combustion gas is adjusted so as to be suitable for being supplied to the heat radiation unit 4. For this temperature control, the supply duct 12
Is provided with a partial exhaust part 10, and a part of the combustion exhaust gas is exhausted from the exhaust port while the exhaust amount is adjusted by a damper provided in the partial exhaust part 10, and at the same time, the burner 1a
The fuel gas supply amount and the air supply amount from the fan 1b provided in the burner are adjusted. With the configuration of the combustor 1 as described above, the heat of the high-temperature combustion gas in the combustion space B does not directly flow out from the wall of the outer cylinder 3, so that heat loss can be reduced and the combustion space B Since the surrounding inner cylinder 2 is surrounded by the exhaust gas whose temperature is lowered by releasing heat in the heat dissipation portion 4, there is a cooling effect by the exhaust gas and is protected from overheating. Further, the exhaust gas in contact with the inner cylinder 2 wall is heated by the inner cylinder 2 wall,
As a result of being preheated until reaching the mixing space M, the temperature difference between the combustion gas and the exhaust gas in the mixing space M can be reduced, and the combustion gas from the mixing space M is diluted with the exhaust gas. It is possible to suppress the temperature unevenness of the diluted combustion gas and stabilize the temperature of the diluted combustion gas. Since the suction fan 6 is arranged as a suction fan on the downstream side of the combustor 1, the combustion space B in the combustor 1 is decompressed and the combustion of the fuel gas supplied from the burner 1a is prevented. Since the air is simultaneously sucked at the same time as being promoted, the fan 1b has a small capacity and a small size, and can fully function.

As described above, according to the present invention, the temperature of the heat radiating surface is made uniform, the unevenness of the heating temperature of the object to be heated is suppressed, and it is compact and easy to attach to and remove from the heating furnace. We were able to obtain a far-infrared burner for a heating furnace that is simple, has good maintainability, and has good fuel efficiency.

Next, another embodiment of the present invention will be described. <1> In the above-described embodiment, the suction fan is used as the circulation blower 6, but the position of the circulation blower 6 may be changed and may be provided on the upstream side of the combustor 1. A circulation blower provided on the upstream side of the combustor 1 and a suction fan provided on the downstream side may be used together. <2> Exhaust gas inflow portion 3 formed in the outer cylinder 3 of the combustor 1
Although a has been described as being formed on the peripheral wall surface of the outer cylinder 3, it may be formed on the side wall of the inner cylinder 2 on the side where the burner 1a is attached. <3> Exhaust gas return pipe 1 forming the exhaust gas return passage 7b
Reference numeral 5 indicates that each of the return passages 5b of the heat radiating portion 4 forms a separate conduit that directly communicates with each other. However, a header is provided in the middle to connect the return collecting duct to the combustor 1. Good.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of a characteristic configuration of the present invention.

FIG. 2 is a plan view showing an embodiment of the present invention.

3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a sectional view taken along the line IV-IV in FIG.

[5] sectional view taken along line V-V arrow view in FIG. 2

FIG. 6 is a partially cutaway explanatory view of a conventional far infrared heater.

[Explanation of symbols]

1 combustor 2 inner cylinder 3 outer cylinder 3a Inflow part 4 Heat sink 5 Combustion gas path 5a Outward route 5b Return path 6 Circulation blower 7 gas circulation 7a Combustion gas supply path 7b Exhaust gas return route 7c Combustion gas suction path

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F27D 7/02 F23D 14/12 F27D 11/02

Claims (4)

(57) [Claims] 1. A heating furnace provided with a combustor (1) and a heat radiating section (4) having a combustion gas passage (5) therein for radiating heat of combustion gas from the combustor (1). A far-infrared heater for use, which forms a gas circulation path (7) for connecting the combustor (1) and the heat radiating portion (4) through a circulation blower (6), and a furnace lid of a heating furnace. The combustor (1), the heat radiating portion (4), and the circulation blower (6) are attached together to a configurable mounting portion to integrally form the combustion gas.
The path (5) communicates with one end side of the heat dissipation section (4).
The combustor is divided into an outward path (5a) and a return path (5b).
Combustion gas from (1) is supplied to the forward path (5a)
Combustion from the burning gas supply path (7a) and the return path (5b)
Exhaust gas return path for returning the exhaust gas to the combustor (1)
(7b) and both are arranged on the other end side of the heat dissipation part (4)
Far-infrared heater for heating furnace you have. 2. A plurality of the combustion gas paths (5) are provided,
Is disposed on the heat radiating portion thereof a plurality of said forward (5a) and the return to (5b) by parallel alternately (4) according to
Item 1. A far-infrared heater for a heating furnace according to Item 1 . 3. The inner cylinder (2), wherein the combustor (1) has a double-cylinder structure composed of an inner cylinder (2) and an outer cylinder (3).
A combustion space (B) is formed inside, and an exhaust gas inflow part (3a) returning from the heat dissipation part (4) is formed between the outer cylinder (3) and the inner cylinder (2). , the downstream side of the inner tube (2), said combustion space the heat radiating portion and the combustion gases from (B) (4) according to claim 1 or is formed with mixing space for mixing the exhaust gas (M) returning from Far-infrared heater for heating furnace according to 2 . 4. A combustion gas suction path for connecting the combustor (1) and the circulation blower (6) by disposing a suction fan on the downstream side of the combustor (1) to form the circulation blower (6). (7c) is formed, the combustion gas supply path (7a) is arranged between the circulation blower (6) and the heat radiating section (4), and the heat radiating section (4) and the combustor (1) are connected to each other. The far-infrared heater for a heating furnace according to any one of claims 1 to 3 , wherein the exhaust gas return path (7b) is arranged between them.