JPH0814788A - Burner - Google Patents

Abstract

PURPOSE:To inhibit superheat of a header and alleviate stress. CONSTITUTION:Heat exchanger tubes 6 are mounted to a plurality of communication holes of a header 4 which passes high temperature combustion gas from a burner section 3 of a combustion unit respectively. While the inner surface of the header 4 is coated on one hand, a header heat shielding plate 9, which communicates with each of the heat exchanger tubes 6, is installed to their respective communication holes. The header 4 is designed to consist of a heat resistant material higher than the header 4.

Description

Detailed Description of the Invention

[0001]

[Industrial field of application] The present invention relates to a combustion device suitable for a hot-air heater that diverts high-temperature combustion gas combusted in a combustion section so as to pass through a plurality of heat exchange pipes by a header section, and particularly relates to heating of the header The present invention relates to a combustion device for which prevention is intended.

[0002]

2. Description of the Related Art Heretofore, as an example of this kind of hot air heater, there is one in which a plurality of heat exchange tubes are arranged in parallel with each other through a header in a combustion cylinder for discharging high temperature combustion gas. this is,
The hot combustion gas from the combustion tube is passed through multiple heat exchange tubes, and the warm air heated outside these heat exchange tubes is blown into the room as warm air by a blower fan to heat it. Since it is divided into multiple heat exchange tubes,
High heat exchange efficiency.

[0003]

However, in such a conventional hot-air heater, since the high-temperature combustion gas is diverted from the relatively wide combustion cylinder into the narrow heat exchange pipes, the header of the diverter portion is divided. The hot combustion gas hits intensively.

Because of this, the header is overheated,
There is a problem in that stress concentration causes the strength of the header to be reduced, resulting in a malfunction such as a failure.

Therefore, the present invention has been made in view of such circumstances, and an object thereof is to provide a combustion device capable of suppressing overheating of a header and reducing stress.

[0006]

The present invention is configured as follows in order to solve the above-mentioned problems.

The invention according to claim 1 of the present application (hereinafter referred to as the first invention) is a combustion apparatus in which heat exchange pipes are respectively attached to a plurality of through holes of a header through which a high-temperature combustion gas from a combustion section is passed, A heat shield plate is provided, which covers the inner surface of the header and has through holes that communicate with the circulation holes.

The invention according to claim 2 of the present application (hereinafter referred to as the second invention) is characterized in that the heat shield plate is made of a heat resistant material higher than that of the header.

Furthermore, the invention according to claim 3 of the present application (hereinafter referred to as the third invention) is characterized in that the heat shield plate is fixed to the header at one place by a coupling member.

Furthermore, in the invention according to claim 4 of the present application (hereinafter referred to as the fourth invention), the heat shield plate projects into the outer peripheral edge portion of each through hole thereof into one end portion of each heat exchange tube. It is characterized in that the cylindrical projection is integrally formed.

In the invention according to claim 5 of the present application (hereinafter referred to as the fifth invention), the heat shield plate has an outer peripheral surface of the cylindrical projection protruding into one end of the heat exchange tube, It is characterized in that it is configured so as not to contact the surface.

[0012]

[Action]

<First to Fifth Inventions> Since the front (inner) surface of the header exposed to high temperature combustion gas is covered with the heat shield plate, overheating of the header can be prevented and stress can be reduced.

<Second Invention> Since the heat shield plate is made of a heat-resistant material higher than that of the header, it is possible to prevent overheating of the heat shield plate itself and reduce stress.

<Third Invention> Since the heat shield plate is fixed to the header at one place by a connecting member such as a rivet,
The thermal elongation becomes free, and the concentration of thermal stress can be suppressed.

<Fourth Invention> Since the connecting end portion between one end of each heat exchange tube and the flow hole of the header is covered with the cylindrical projection of the heat shield plate, the thermal stress at one end of each heat exchange tube is covered. Concentration can be suppressed.

<Fifth Invention> Since the outer peripheral surface of the cylindrical projection projecting into one end of the heat exchange tube of the heat shield plate is configured not to contact the inner surface of the heat exchange tube, the high heat of the heat shield plate is It is possible to suppress heat transfer to the heat exchange tube and adverse effects.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS. 1 to 7, the same or corresponding parts are designated by the same reference numerals.

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention. In FIG. 1, the combustion device 1 is applied to, for example, a hot air heater, and has a cylindrical shape shown in FIGS. 2 and 3. The burner section 3 of the combustion section that burns the fuel to generate the flame and the high-temperature combustion gas is concentrically connected to the open end of the combustion tube 2 of FIG. The high temperature combustion gas is discharged from the gas discharge port.

The upper half of the header 4 made of, for example, SUS304 is fixed to the open end of the combustion gas discharge port of the combustion cylinder 2 by caulking as shown in FIG. 4 (A).

The header 4 has a left side surface (inner surface) in FIG.
In addition, a bottomed bowl-shaped header cover 5 covering the entire surface
Is attached to divert the flow of the high temperature combustion gas from the combustion tube 2 to the lower half of the header 4.

Circular flow holes 4a, for example, are formed in the lower half of the header 4 so as to penetrate in the plate thickness direction, and a plurality of heat holes shown in FIGS. One end of the exchange tube 6 is attached by caulking or the like as shown in FIG. 4 (B) to form a multi-tube heat exchanger. The other end of each heat exchange tube 6 is concentrically fixed to each mounting hole 7a of the disk-shaped end plate 7 shown in FIGS. 2 and 3, and the bottom surface of the end plate 7 is a cylindrical exhaust gas. The cover 8 is concentrically fixed, and combustion gas is exhausted to the outside from an exhaust portion 8a of the exhaust cover 8.

On the inner surface of the lower half of the header 4, a header heat shield plate 9 shown in FIGS. 6 and 7A is fixed to cover the inner surface of the lower half of the header 4.

The header heat shield 9 is made of, for example, S, which is a material having higher heat resistance than the header 4 made of SUS304 or the like.
The through holes 9a are formed by US310 and correspond to the respective through holes 4a of the header 4 by, for example, burring, and each through hole 9a is formed from the inner diameter of each heat exchange tube 6 as shown in FIG. Also, a cylindrical burring portion 9b, which has a slightly smaller diameter and is concentrically provided with play and slightly protrudes, is formed in each one end.

As shown in FIG. 6, the header heat shield plate 9 has a rivet hole 9c formed in its upper portion, and
As shown in (B), a circular recess 9d that slightly recesses the periphery of the rivet hole 9c toward the header 4 side is formed.

Therefore, as shown in FIG.
The bottom surface of the concave portion 9d of c is brought into close contact with the inner surface of the header 4,
By inserting the rivet 10 into the rivet hole 9c and caulking it, the header heat shield plate 9 is slightly floated on the inner surface of the header 4 and fixed with a small gap, and the inner surface of the header 4 is fixed. It is covered by.

Therefore, the high-temperature combustion gas generated in the burner section 3 flows through the combustion cylinder 2 as shown by the arrow in FIG. 1 into the flow dividing section formed by the header 4 and the header cover 5, where The heat is divided into the heat exchange tubes 6, and each heat exchange tube 6 is heated to exchange heat with the outside air.

That is, the outside air around each heat exchange tube 6 is heated and blown into the room as warm air by a blower fan (not shown) to heat the room. Then, the combustion gas flowing in each heat exchange pipe 6 is exhausted to the outside from the exhaust portion 8a of the exhaust cover 8.

Therefore, according to the present embodiment, since the inner surface of the header 4 exposed to the high temperature combustion gas is covered with the header heat shield plate 9, it is possible to prevent the header 4 from overheating and reduce the stress. Further, since the header heat shield plate 9 is made of a heat resistant material higher than that of the header 4, the heat shield plate 9 is
It is possible to prevent overheating of itself and reduce stress. Further, the header heat shield plate 9 has a rivet 10 on the header 4.
Since it is fixed at one place, the thermal expansion becomes free and the concentration of thermal stress can be suppressed. Further, since the burring portion 9b of the header heat shield plate 9 covers one end portion of each heat exchange pipe 6 and each connection hole 4a of the header 4, the heat of the connection end portion with each heat exchange pipe 6 is covered. Stress concentration can be suppressed. Further, since the outer peripheral surface of each burring portion 9b projecting into one end of each heat exchange tube 6 of the header heat shield plate 9 is configured not to contact the inner surface of each heat exchange tube 6, high heat of the header heat shield plate 9 is formed. However, it is possible to suppress heat transfer to each heat exchange tube 6 and adverse effects.

[0029]

As described above, in the first to fourth inventions of the present application, since the inner surface of the header exposed to the high temperature combustion gas is covered with the heat shield plate, overheating of the header is prevented and stress is reduced. be able to. Further, in the second invention of the present application, since the heat shield plate is made of a heat-resistant material higher than the header, it is possible to prevent overheating of the heat shield plate itself and reduce stress.

Further, in the third invention of the present application, since the heat shield plate is fixed to the header at one place by a connecting member such as a rivet, thermal expansion becomes free and the concentration of thermal stress can be suppressed.

Furthermore, in the fourth invention of the present application, the cylindrical projection of the heat shield plate covers the connection end portion between one end of each heat exchange tube and the flow hole of the header, so that the heat exchange tubes are connected to each other. It is possible to suppress the thermal stress concentration at the connection end.

Further, in the fifth aspect of the present invention, since the outer peripheral surface of the cylindrical projection protruding into one end of the heat exchange tube of the heat shield plate is configured not to contact the inner surface of the heat exchange tube, It is possible to prevent high heat from being transferred to the heat exchange tube and adversely affecting it.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the almost entire configuration of an embodiment of a combustion apparatus according to the present invention.

FIG. 2 is a partially cutaway front view of a main part shown in FIG.

FIG. 3 is a right side view of FIG.

4 (A), (B), and (C) are A, B, and B shown in FIG.
An enlarged view of each part of C.

FIG. 5 is an enlarged view of a main part of FIG.

6 is a front view of the header heat shield plate shown in FIG. 1. FIG.

7 (A) is a side view of the header heat shield shown in FIG. 6,
(B) is a side sectional view of the rivet hole portion.

[Explanation of symbols]

 1 Combustion device 2 Combustion tube 3 Burner part 4 Header 4a Distribution hole 5 Header cover 6 Heat exchange pipe 7 End plate 8 Exhaust cover 9 Header heat shield plate 9a Through hole 9b Burring part 9c Rivet hole 9d Recess 10 Rivet

Claims (5)

[Claims] 1. A combustion apparatus comprising a multi-tube heat exchanger in which a plurality of heat exchange tubes for passing combustion gas from the combustion section are arranged in parallel, wherein a front surface of a header portion of the multi-tube heat exchanger comprises: A combustion apparatus, which is provided with a heat shield plate which covers the header and has a through hole in a portion facing the opening of the heat exchange tube. 2. The combustion apparatus according to claim 1, wherein the heat shield plate is made of a heat-resistant material higher than that of the header. 3. The heat shield plate is attached to the header by a connecting member.
The combustion device according to claim 1 or 2, wherein the combustion device is fixed in place. 4. The heat shield plate is integrally formed with a cylindrical protrusion projecting into one end of each heat exchange tube at an outer peripheral edge of each through hole thereof. The combustion device according to claim 1. 5. The combustion apparatus according to claim 4, wherein the heat shield plate is configured so that an outer peripheral surface of the cylindrical projection protruding into one end portion of the heat exchange tube does not contact the inner surface of the heat exchange tube. .