JPH07305811A - Burner - Google Patents

Abstract

PURPOSE:To provide a burner in which the variation of a burning state due to a temperature rise of the burner is prevented, the state of a flame is always stabilized and generation of nitrogen oxide is little. CONSTITUTION:The burner comprises a burning tube body 2, two thick mixed gas passages 3 and a burner port member 5. The passage 3 is formed of an inner surface plate and an outer surface plate, and has a thick gas path therein. The inner and outer surface plates of the passage 3 are spot welded to the body 2 at protruding parts. Thick mixed gas is introduced from the body 2 to the passage 3 via a communicating hole, and exhausted from an auxiliary flame burner port. The mixed gas is mixed with the air in a mixing chamber to become thin mixed gas, which is discharged from the member 5 to generate a main flame.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device, and more particularly to a combustion device suitable for application to a small boiler or a hot water supply device.

[0002]

2. Description of the Related Art A combustion device is a main component of a boiler and a hot water supply device, and is widely used not only in factories but also in general households. By the way, in recent years become the environmental destruction is serious social problems caused by acid rain, to reduce the total emissions of NO _X (nitrogen oxide) there is an urgent need. Therefore, even for small-sized combustors for home use and the like, it is required to devise to reduce the generation of NO _X as much as possible.

As a measure for reducing NO _X in the field of small-sized combustion devices, a method of burning fuel gas in a lean state can be considered. However, when the fuel gas is diluted and burned, the flame lifts and the flame becomes instable. Therefore, as a countermeasure against this, the adoption of a combustion method called dark and light combustion is drawing attention. Here, rich-lean combustion means that a main flame is generated from a lean mixed gas (hereinafter referred to as a light mixed gas) in which fuel gas is premixed with about 1.6 times the stoichiometric amount of air, and air is generated near the main flame. The auxiliary flame generated from a mixed gas (hereinafter, referred to as a concentrated mixed gas) having a small amount of mixed fuel and a high fuel gas concentration is arranged.

As a combustion device to which the dark and light combustion is applied, a structure as disclosed in, for example, Japanese Patent Laid-Open No. 5-118516 is known. In the combustion device disclosed in Japanese Patent Laid-Open No. 5-118516, the fuel supply system is divided into a plurality of parts, and the supply system is further subdivided to provide a rich mixed gas supply system and a light mixed gas supply system. A structure that supplies mixed gas from the system to the flame holes is adopted. However, the combustion device having the above-described configuration has a complicated fuel supply system,
There is a problem that it requires an installation space and is difficult to assemble and construct on site.

Therefore, the present applicant previously proposed a combustion device for producing a mixed gas of two kinds of light and shade in the device (Japanese Patent Application No. 4-35).
8484). The combustion apparatus proposed by the present applicant has a press structure, and a plurality of metal plates are stacked with a predetermined gap therebetween, and a plurality of gas passages are formed by the gaps of the metal plates. And each gas flow path is connecting through the small hole. In the prior art combustion device, the concentrated mixed gas is supplied to one of the gas flow paths. Then, the concentrated mixed gas is distributed at a constant distribution rate to the central and peripheral gas flow paths through the small holes. Further, in the central gas flow passage, air is further mixed and diluted. Then, the light mixed gas generates a main flame, and the rich mixed gas distributed to the surroundings generates a supplementary flame.

In the above-mentioned conventional combustion apparatus, each metal plate is joined only at its end portion, and all of its intermediate portions are open.

[0007]

The combustion device previously proposed by the applicant of the present invention is preferable because it has a simple fuel supply system and does not require an installation space. However, the conventional combustion apparatus has a drawback that the combustion state changes with the lapse of time after ignition. When the cause of this was investigated, it was because the temperature of the combustion device itself increased and the combustion device was deformed after a short time from ignition. That is, in the conventional combustion apparatus, each metal plate is joined only at its end, so the distance between the joined parts is long and the metal plate is bent due to the influence of temperature. In particular, in the conventional combustion device, since the gas flow path is formed by the gap between the metal plates, the cross-sectional area and the shape of the gas flow path largely change due to the deformation of the metal plate, and the original mixing ratio and gas This is because the flow velocity cannot be maintained. SUMMARY OF THE INVENTION The present invention focuses on the above-mentioned problems of the prior art, and aims to provide an improved combustion apparatus in which the state of the flame is always stable while improving the conventional technology and providing the advantages of the conventional technology.

[0008]

The present invention for achieving the above object is a combustion device for injecting a mixed gas of fuel and air from a flame hole to generate a flame, and a predetermined gap is provided. In a combustion apparatus including a plurality of metal plates arranged in advance and forming a gas flow path by the metal plates, the metal plates are joined at an intermediate portion.

In a preferred invention as an embodiment of the above-mentioned invention, a projection is provided on at least one of adjacent metal plates, the projection is brought into contact with the adjacent metal plate, and the top surface of the projection and the adjacent metal plate. 2. The combustion device according to claim 1, wherein the gas flow path is divided by the protrusions.

Another aspect of the present invention for achieving the same object is a combustion tube body for supplying a fuel gas or a high concentration fuel gas, and a rich mixed gas for guiding the fuel gas or the high concentration fuel gas to a flame hole. The combustion tube body and the rich mixed gas passage portion each have a metal plate arranged therein and a gas flow path is formed by the metal plate. The mixed gas passages are arranged in parallel in a state of protruding from the top of the combustion tube body, and a space serving as a mixing chamber is formed between the top of the combustion tube body and the wall surface of the rich mixed gas passage portion. This is a combustion device in which communication holes are provided between the rich mixed gas passage portions, and holes for supplying fuel gas or high-concentration fuel gas to the mixing chamber are provided in the combustion tube body or the rich mixed gas passage portion. The combustion tube body and rich mixed gas Over parts, the ends each other are joined,
Further, the metal plate forming the rich mixed gas passage portion and the combustion tube main body are joined together in the middle portion.

In a preferred invention as an embodiment of the above-mentioned invention, the rich mixed gas passage portion is composed of an outer metal plate and an inner metal plate, and the outer metal plate faces the rich mixed gas passage portion side. A protruding protrusion is provided, the top surface of the protrusion contacts the inner metal plate, and the top surface of the protrusion of the outer metal plate and the protrusion contact portion of the inner metal plate are integrally joined. In the portion, the rich mixed gas passage portion and the combustion pipe main body are joined, and a communication hole that communicates the combustion pipe body and the rich mixed gas passage portion is formed immediately below the joint portion of the three members.

[0012]

In the combustion apparatus of the present invention, since the metal plates are joined at the intermediate portion, the distance between the joined portions is short. Therefore, in the combustion apparatus of the present invention, even if the temperature of the apparatus itself changes, the metal plate is hard to bend, and the change in cross-sectional area and cross-sectional shape of the gas flow path is small.

In the combustion apparatus according to the second aspect, the metal plate is provided with the projection, and the top surface of the projection is in contact with the adjacent metal plate, so that it is easy to secure a gap between the metal plates. Further, since the projection is present in the gas flow path and a part of the flow path is divided by the projection, the projection functions as a baffle plate for the gas and has an action of promoting mixing and dispersion of the gas.

According to the third aspect of the invention, the fuel gas or the high-concentration fuel gas is supplied from the main body of the combustion tube. Then, a part of the fuel gas flows to the rich mixed gas passage portion through the communication hole provided between the combustion pipe body and the rich mixed gas passage portion,
It is discharged from the flame holes that burn the rich mixed gas to form a supplementary flame. On the other hand, the remaining portion of the fuel gas flows from the holes provided in the combustion tube body or the rich mixed gas passage portion to the space formed between the top of the combustion tube body and the wall surface of the rich mixed gas passage portion. Then, in this space, the rich mixed gas is mixed with air. The light mixed gas thus mixed is guided to the flame holes to form the main flame.

The main flame has a low concentration of fuel gas,
In the present invention, since the stable supplementary flame exists near the main flame, the combustion of the main flame is stable. In the combustion apparatus of the present invention, the metal plates forming the rich mixed gas passage portion and the combustion tube body are joined together at the intermediate portion, so that the plate of the rich mixed gas passage portion has a distance between the joining portions. Is short, and the amount of bending due to temperature rise is small. Therefore, in the combustion device of the present invention, the cross-sectional area change of the rich mixed gas passage portion due to the temperature rise is small.

In the combustion device according to the fourth aspect, in addition to the above-mentioned action, there is an action of promoting gas mixing and dispersion. That is, in the combustion apparatus of the present invention, the rich mixed gas passage portion is composed of the outer metal plate and the inner metal plate, the outer metal plate is provided with a protrusion, and the top surface of the protrusion is in contact with the inner metal plate. Touching. Therefore, there are protrusions in the rich mixed gas passage portion. Further, a communication hole that communicates the main body of the combustion tube with the rich mixed gas passage is formed immediately below the protrusion. Therefore, when the rich mixed gas or the like entered from the communication hole rises in the rich mixed gas passage portion toward the flame hole, the rich mixed gas or the like hits the protrusions and is dispersed. Therefore, the gas flow in the rich mixed gas passage becomes uniform.

[0017]

EXAMPLES Specific examples of the present invention will be described below. In the following description, the upper and lower sides are based on the state in which the combustion device 1 is installed with the flame holes facing upward. FIG. 1 is a perspective view of a combustion apparatus according to a specific embodiment of the present invention. FIG. 2 is a plan view of the case where the combustion apparatus of FIG. 1 is housed in a case. FIG. 3 is an exploded perspective view of the combustion device of FIG.
FIG. 4 is a front view (b) and a plan view (a) of the combustion tube body. FIG. 5 is a front view (b), a plan view (a) and a rear view (c) of the rich mixed gas passage portion. FIG. 6 shows FIG.
It is an enlarged view in the AA cross section of. FIG. 7 is an enlarged view of the end portion of FIG. 8A and 8B are explanatory views showing the manufacturing process of the concentrated mixed gas passage portion. FIG. 9 is an enlarged view of the upper end of the BB cross section of FIG. Figure 10 (a)
(B) is explanatory drawing which shows the manufacturing process of a dense mixed gas passage part. FIG. 11 is an enlarged view of the lower end of the BB cross section of FIG. FIG. 12 is an enlarged plan view of the combustion device of FIG. FIG. 13 is an enlarged cross-sectional view of the upper end portion of the combustion device of FIG. FIG. 14 is a development view of the flame hole member. Figure 15
FIG. 2 is a sectional view taken along the plane C of FIG. FIG. 16 is a cross-sectional view taken along plane D of FIG. FIG. 17 is a perspective view of the combustion apparatus with one of the rich mixed gas passage portions and the flame hole member removed. 18 is a partial cross-sectional perspective view of the combustion device of FIG. FIG. 19 is an explanatory diagram showing the relationship between the dense mixed gas passage portion and the flame hole member.

As shown in FIG. 2, the combustion apparatus 1 of this embodiment is used in parallel with the case 4 or used alone. As shown in FIG. 3, the structure of the combustion device 1 includes a combustion tube body 2, two rich mixed gas passage portions 3, and a flame hole member 5.
Consists of The combustion tube main body 2 is formed by pressing a single steel plate to form a developed pattern having irregularities on the surface, bending it, and then joining it by spot welding.
The spot welding is performed not only on the peripheral flange portion 7 but also on the intermediate portion 10 of the conducting portion 12 described later.

The shape of the combustion tube body 2 after assembly is shown in FIG.
A front plate 8 as shown in (a) and a symmetrical back plate 9 are superposed on the front plate 8. The external appearance of the combustion tube body 2 is flat, has a top portion 22, and the periphery is closed so that gas does not leak. And inside the front plate 8 and the back plate 9
A series of gas flow paths are formed by the spaces. That is, in the portion where the concavities and convexities of the front plate 8 and the back plate 9 match, the metal plates are arranged with a gap therebetween, and the gap forms a gas flow path.

In the combustion tube body 2 adopted in this embodiment, the gas flow passage is roughly divided into a mixing portion 11, a conducting portion 12,
It consists of the discharge part 13. Explaining from the inlet of the gas flow path,
A fuel gas introduction hole 14 is opened at the lower corner of the combustion device 1 as shown in FIGS. 1, 3, 4, and 18. The cross-sectional area inside the fuel gas introduction hole 14 gradually increases,
Further, the flow path is largely changed in direction to form the mixing section 11. The end of the mixing portion 11 extends over the entire region in the longitudinal direction at a position at the middle height of the combustion tube body 2. The conducting part 12 connects the end of the mixing part 11 and the discharge part 13, is continuous with the end of the mixing part 11, and extends over the entire region of the combustion tube body 2 in the longitudinal direction. The cross-sectional area of the conducting portion 12, that is, the gap between the front plate 8 and the back plate 9 at that portion is shown in FIG.
It's as small as 5,16.

The discharge portion 13 is located at the upper end portion of the combustion tube main body 2 and extends over the entire longitudinal direction. The cross-sectional area of the discharge part 13, in other words, the gap between the front plate 8 and the back plate 9 at that portion is large as shown in FIGS. On the outer surface of the emitting portion 13, there are provided five protruding portions (projections protruding outward) 15 on both the front plate 8 and the back plate 9, respectively. Then, one hole 1 is provided in each of the protruding portions 15.
6 is provided. The hole 16 is formed by a burring process, and its edge stands vertically from the surface of the front plate 8 or the like.

The other flat portion 18 of the outer surface of the discharge portion 13 is recessed from the protruding portion 15 when viewed from the outside,
The hole 20 is also provided in this portion. The hole 20 is smaller than the hole 16 of the protrusion 15 described above. Four holes 20 of the flat portion 18 are provided in each of the flat portions 18 except the end portion. The holes 20 are not evenly spaced, and are provided so as to be biased toward the protruding portion 15 side. In this way, the protrusion 15
The reason why the holes 20 are provided on one side is that the dense mixed gas passage 3 is in close contact with the protrusion 15 as will be described later, so that the protrusion 1
This is because it becomes difficult for the mixed gas to flow to the 5 side, and the hole 20
This is because the flame tends to be small at the upper portion of the protruding portion 15 when they are evenly arranged. Ejector 13
There is no opening at the top 22 of the.

Next, the structure of the rich mixed gas passage portion 3 will be described. The rich mixed gas passage portion 3 is also the combustion tube body 2 described above.
Similarly to the above, one steel plate is pressed to form a developed pattern having irregularities, and this is bent. The rich mixed gas passage portion 3 also uses spot welding, but since spot welding is performed integrally with the combustion tube body 2, only the external shape will be described here.

Note that FIG. 5 is a front view (b), a plan view (a) and a rear view (c) of the rich mixed gas passage portion 3, but in FIG. The front view shows the inside. Thick mixed gas passage 3
As shown in FIGS. 5, 6, 15 and 16, the inner surface plate 23 and the outer surface plate 25 are arranged with a gap therebetween, and a top portion 34 having a small area is provided, and other portions are folded back so that gas does not leak. It is a thing. The gap between the inner surface plate 23 and the outer surface plate 25 forms a gas flow path inside the rich mixed gas passage portion 3. That is, the rich mixed gas passage portion 3 functions as a gas flow path from the bottom to the top in the entire area inside.

The inner surface plate 23 and the outer surface plate 25 of the rich mixed gas passage portion 3 are concave in overall shape, and flange portions 24 are provided at both ends in the longitudinal direction, and the inner surface plate 23 and the outer surface plate 25 are provided. Are in contact with each other at the flange portion 24. The recesses of the inner surface plate 23 of the rich mixed gas passage portion 3 are provided with ridges 26, 28, 30 having a complicated shape as shown in FIG.
That is, the inner surface plate 23 is provided with five ridges 26 extending in the short direction at equal intervals. The ridge 26 is one of the protrusions as a component of the present invention.

Further, there is provided a ridge 28 having a relatively low height which connects the lower side of the five ridges 26 in the longitudinal direction.
Furthermore, a protrusion 30 is provided which connects the upper portions of the five protrusions 26 in the longitudinal direction. A bulge portion 27 is provided at a height level with the five ridges 26 and between the flange 24 and the recess (see FIGS. 5 and 7). Bulge 27
When the combustion device 1 is assembled, the function of (1) makes the corners of the rich mixed gas passage portion 3 and the corners of the combustion tube main body 2 closely contact with each other so that no gap is formed in the portion.

Holes 31 are provided in each of the five protrusions 26. A large number of small holes 32 are provided in the inner wall portion 29 between the ridge 30 and the top portion. The outer surface plate 25 of the rich mixed gas passage portion 3 is provided with five protrusions 33 (mortar-shaped recesses when viewed from the outside) protruding toward the rich mixed gas passage portion 3 side. The positions of the tops of the protrusions 33 coincide with the positions directly behind the five protrusions 26 of the inner surface plate 23 described above.

Further, the outer surface plate 25 is provided with six small protrusions 39. Although the combustion apparatus of this embodiment has two left and right rich mixed gas passage portions 3, the small protrusions 39 are provided at different positions in the left and right rich mixed gas passage portions 3. Flame holes 35 for supplementary flames are arranged in a line at the top portion 34 of the rich mixed gas passage portion 3. Moving the eyes to the internal structure of the rich mixed gas passage portion 3, the top surface of the protrusion 33 of the outer surface plate 25 is the inner surface plate 23.
In contact with the back surface of the five ridges 26, there is a slight gap between the outer surface plate 25 and the inner surface plate 23 at the other portions.

The details of the rich mixed gas passage portion 3 will be added. The flange portion 2 at the top 34 of the rich mixed gas passage portion 3 is described.
4 to the recess, a fold-back rib 37 is provided at the projecting end portion of the outer surface plate 25. The fold-back rib 37
Covers the corners of the top portion 34 of the rich mixed gas passage portion 3 (see FIGS. 8 and 9). The reason for such a configuration is to prevent the mixed gas from leaking from the corner of the top portion 34 of the rich mixed gas passage portion 3. Further, at the lower end of the rich mixed gas passage portion 3, a folding rib 38 is provided at the projecting end portion of the inner surface plate 23, and the folding rib 38 is folded back to cover the lower corner portion of the rich mixed gas passage portion 3. Covering (Fig. 1
0, see FIG. 11).

Next, the flame hole member 5 will be described. The flame hole member 5 used in this embodiment is obtained by press-molding one plate,
Furthermore, it was made by sequentially bending it. That is, the flame hole member 5 used in the present embodiment is made of a development plate 40 having a shape as shown in FIG. 14 obtained by pressing a single steel plate. The shape of the spreading plate 40 is 10 strips 41, 42, 43, 4
4, 45, 46, 47, 48, 49 and 50 are connected by three connecting pieces 51 each having an extremely thin width.

The shape of each strip is the two outermost strips 4.
1 and 50 are the same, and a strip 42 and a strip 49, a strip 43 and a strip 48, a strip 44 and a strip 47, and a strip 45 and a strip 46 have the same shape, respectively. The strips 41 and 50 have connecting pieces 5
A ridge 53 continuous in the longitudinal direction is provided at a position closer to the position 1. It also has two round protrusions 55. And strip 4
A large number of small holes 56 are provided in the longitudinal direction in the central portions of 1, 50. Further, a rectangular embossing 57 is formed at a position on the opposite side of the connecting piece 51 of the strips 41 and 50.

The strips 42 and 49 are provided with elongated holes 58 arranged in the longitudinal direction and a square embossing 60. The strips 43 and 48 are provided with two types of square embossing 61 and 62 of different sizes. The strips 44 and 45 are provided with a long hole 65 and a square embossing 66, and a small hole 67 is provided in a part of the embossing 66. The flame hole member 5 used in this embodiment is formed by bending each strip from the connecting piece 51 in alternate directions as shown in FIG. 13 to form a quadrangular prism shape as a whole.
When the flame hole member 5 is bent, each strip 41, 42, 43,
The embossed portions provided at 44, 45, 46, 47, 48, 49 and 50 are brought into contact with the protrusions, and a gap 63 is formed between the strips as shown in FIG. This gap 63
Has a function of rectifying and passing the light mixed gas, and the opening at the upper end functions as a flame hole of the main flame.

Next, the relationship between the members of the combustion apparatus 1 of this embodiment will be described. In the combustion device 1 of this embodiment,
With the combustion tube body 2 as the center, left and right rich mixed gas passages 3
And the flame hole member 5 is mounted on the upper portion of the combustion tube main body 2 between the rich mixed gas passage portions 3. The positional relationship between the combustion tube body 2 and the rich mixed gas passage portion 3 is
The rich mixed gas passage portions 3 are arranged in parallel so as to project from the top portion 22 of the combustion tube body 2. In other words, the top portion 22 of the combustion tube body 2 is the top portion 34 of the rich mixed gas passage portion 3.
And the combustion pipe body 2 is located below the
It is located in a valley sandwiched between. Therefore, at the top portion 22 of the combustion tube body 2, there is a space sandwiched by the inner wall portions 29 of the rich mixed gas passage portion 3. This space is a mixing chamber 70
Function as.

In the state where the combustion tube body 2 and the rich mixed gas passage portion 3 are combined with each other, the protrusion 15 provided on the discharge portion 13 of the combustion tube body 2 and the ridge of the inner surface plate 23 of the rich mixture gas passage portion 3. 26 are closely attached. Therefore, a space is formed between the portion other than the protrusion, more specifically, between the flat portion 18 of the combustion tube body 2 and the flat portion 71 of the rich mixed gas passage portion 3. This space functions as the light mixed gas flow path 73.

When the combustion tube body 2 and the rich mixed gas passage portion 3 are assembled together, the hole 1 of the combustion tube body 2 as shown in FIG.
6 is matched with the hole 31 of the rich mixed gas passage portion 3. In the present embodiment, the hole 16 of the combustion tube body 2 is burred and the periphery of the hole 16 stands, so that the hole 16 is formed.
The periphery of is fitted into the hole 31 of the rich mixed gas passage portion 3 and communicates therewith. The flame hole member 5 is a space sandwiched by the inner wall portions 29 of the rich mixed gas passage portion 3 and is located at a position slightly apart from the top of the combustion tube body 2. In the flame hole member 5, the ridges 53 of the strips 41 and 50 on the outermost surface ride on the stepped portions of the ridges 30 of the rich mixed gas passage portion 3, and the round protrusions 55 of the strips 41 and 50 form the rich mixed gas. The inner wall portion 29 of the passage portion 3 is brought into contact with and positioned.

It should be noted here that, in the combustion apparatus 1 of this embodiment, spot welding is used for joining the combustion tube body 2 and the rich mixed gas passage portion 3. That is, the combustion tube main body 2 and the rich mixed gas passage portion 3 are placed in the above-mentioned positional relationship.
With the flame hole member 5 arranged, the end portions of the combustion pipe body 2 and the rich mixed gas passage portion 3, that is, the flange portion 7 of the combustion pipe body 2 and the flange portion 24 of the rich mixed gas passage portion 3 are It is joined by spot welding.

In addition, in this embodiment, the spot welding electrode is brought into contact with the back surface of the projection 33 on the outer surface plate 25 of each of the rich mixed gas passage portions 3 (the depth of the recess when viewed from the outside). The combustion tube body 2 and the rich mixed gas passage portion 3 are joined together. As a result, as shown in FIG.
Inner plate 23, outer plate 25, and ridge 2 of the combustion tube body 2
The three parts of the six parts are integrally joined. That is, in the rich mixed gas passage portion 3, the inner surface plate 2 that constitutes the rich mixed gas flow path
3 and the outer surface plate 25 are joined at both ends and an intermediate portion. Therefore, in the rich mixed gas passage portion 3, a part of the rich mixed gas passage is divided by the protrusion 33. Further, the inner surface plate 2 of the rich mixed gas passage portion 3 which constitutes the light mixed gas flow path 73
3 and the front plate 8 of the combustion tube main body 2 are joined at both ends and an intermediate portion to divide the flow path. The same applies to the relationship between the inner surface plate 23 of the rich mixed gas passage portion 3 and the back plate 9 of the combustion tube body 2.

Next, the flow of the mixed gas in the combustion apparatus 1 of this embodiment will be described. In the combustion apparatus 1 of this embodiment, a fuel gas nozzle (not shown) is inserted into the introduction hole 14 of the combustion tube body 2. The insertion state of the gas nozzle is similar to that of a normal Bunsen type combustion burner, there is a gap or opening between the introduction hole 14 and the gas nozzle, and air is mixed in the combustion tube body 2 together with the fuel gas. The mixing ratio of air to the fuel gas is about 40% of the theoretical air amount, and the fuel gas concentration is high. This rich mixed gas is introduced into the introduction hole 14
From the to the mixing section 11, when changing the direction, it abuts the inner wall surface of the gas flow path formed by the front plate 8 and the back plate 9, which are two metal plates, to promote mixing.

Then, the rich mixed gas enters the discharge part 13 from the mixing part 11 through the conducting part 12. Here, in this embodiment,
Since the conducting portion 12 has a small cross-sectional area and is a thin channel, the gas in the mixing portion 11 is squeezed in the portion,
From each position in the longitudinal direction of the conducting portion 12, the discharge portion 13 enters into the discharging portion 13 at a substantially equal ratio.

The rich mixed gas that has entered the discharge part 13 has holes 16
And emitted from the holes 20. The subsequent passage of the mixed gas is divided into the flow of the concentrated mixed gas and the passage of the light mixed gas, and therefore will be described separately. Describing from the flow of the rich mixed gas, the rich mixed gas enters the rich mixed gas passage portion 3 from the hole 16 provided in the projecting portion 15 of the discharge portion 13. That is, as described above, the protruding portion 15 of the discharge portion 13 is burred, and the burring portion is the concentrated mixed gas passage portion 3.
It is inserted into the hole 31 provided in the ridge 26, and the hole 16 of the combustion tube body 2 and the hole 31 of the rich mixed gas passage portion 3 communicate with each other. Therefore, all the rich mixed gas discharged from the holes 16 provided in the protruding portion 15 among the holes provided in the combustion tube main body 2 enters the rich mixed gas passage portion 3. The amount of gas introduced into the rich mixed gas passage portion 3 is about 30% of the total amount of gas released from the combustion tube body 2.

The concentrated mixed gas that has entered the concentrated mixed gas passage portion 3 through the holes 16 and 31 is the outer surface plate 25 of the concentrated mixed gas passage portion 3.
At the same time, the gas flow path formed by the gap between the outer surface plate 25 and the inner surface plate 23 rises. However, as shown in FIG. 15, there is a projection 33 of the outer surface plate 25 directly above the hole 16, and the top surface of this projection 33 is spot welded to the back side of the inner surface plate 23, so that the rich mixed gas is You cannot rise right above. Therefore, the rich mixed gas spreads along the convex surface of the mortar-like shape, and the rich mixed gas passage portion 3 as shown by the arrow in FIG.
Will uniformly rise over the entire area in the longitudinal direction.

Then, the rich mixed gas is uniformly ejected to the outside from the flame hole 35 provided in the top portion 34. Thick mixed gas passage 3
Since the surroundings are closed and air does not enter, the mixed gas injected from the flame hole 35 via the rich mixed gas passage portion 3 is the rich mixed gas released from the combustion tube body 2. As it is, the concentration of fuel gas is high. Further, the rich mixed gas is discharged from the small hole 32 provided in the inner wall portion 29 of the rich mixed gas passage portion 3 toward the flame hole member 5 side.

Next, the path of the light mixed gas will be described.
The flat portion 18 of the rich mixed gas that has entered the discharge portion 13 described above.
The concentrated mixed gas discharged from the holes 20 provided in the
6 and 17, they are discharged to the light mixed gas passage 73 formed between the combustion pipe main body 2 and the rich mixed gas passage portion 3 and rise. Here, the lower portion of the light mixed gas flow path 73 is opened as shown in FIG. Therefore, the rich mixed gas discharged from the hole 20 is mixed with the air sucked from the lower opening 76 to become a light mixed gas. And the light mixed gas is mixed in the mixing chamber 7
Enter 0. Then, the light mixed gas rises evenly from the mixing chamber 70, enters the groove of the flame hole member 5, and is injected to the outside from the flame hole. Therefore, the light mixed gas is evenly injected from most of the flame hole member 5.

In the combustion apparatus 1 of this embodiment, the flame hole member 5
From the boundary portion of the dense mixed gas passage portion 3, a mixed gas having an intermediate concentration is injected. The gas path of the portion will be described based on FIG. In the combustion device 1 of this embodiment, the small hole 32 is provided in the inner wall portion 29 of the rich mixed gas passage portion 3. Therefore, as described above, the rich mixed gas is discharged from the small holes toward the flame hole member 5. From the mixing chamber 70, the light mixed gas rises through the gap between the combustion members, and part of the light mixed gas is strip-shaped plate 41 (5).
It is discharged from the small holes 56 of 0) between the flame hole member 5 and the rich mixed gas passage portion 3. Therefore, the mixed gas having an intermediate concentration is injected from between the rich mixed gas passage portion 3 and the flame hole member 5.

In the combustion apparatus 1 of this embodiment, the mixed gas is
The light mixed gas is injected from the opening of the flame hole member 5, and the rich mixed gas is injected from the flame hole 35 of the rich mixed gas passage portion 3, following the respective paths described above. Then, a mixed gas having an intermediate concentration is injected from between the flame hole member 5 and the concentrated mixed gas passage portion 3. Therefore, the main flame generated by the light mixed gas is surrounded by the supplementary flame generated by the rich mixed gas, and an intermediate flame generated by the mixed gas of intermediate concentration is present in the intermediate portion between the main flame and the supplementary flame. , Smooth connection between main flame and supplementary flame. Thus the combustion apparatus of this embodiment, without causing lift of the flame, has the effect of the fuel gas can be burned in a lean state, it is possible to reduce the occurrence of NO _X.

When the combustion device 1 of this embodiment is ignited and time elapses, the temperature of the combustion device 1 itself rises, and each metal plate constituting the fluid flow path thermally expands. However, in the combustion apparatus 1 of the present embodiment, the rich mixed gas passage portion 3 is bonded between the outer surface plate 25 and the inner surface plate 23 not only by the flange portions 24 at both ends but also by the protrusion 33 positioned in the middle. The flow path is divided. Therefore, the metal plate forming the rich mixed gas passage portion 3 has a short distance between the joint portions and is less likely to be deformed even when the temperature rises. Therefore, the cross-sectional area change of the gas flow path is small, and the flame hole 3
The flow rate, flow rate and distribution of the concentrated mixed gas injected from No. 5 are constant. Therefore, the combustion of the supplementary flame is stable.

On the other hand, also in the light mixed gas flow path 73, the projection 26 of the inner surface plate 23 and the projection 15 of the combustion tube main body 2 are joined by spot welding, so that the gas flow path 73 concerned.
The metal plate forming the metal plate has a short bonding interval. Therefore, even if the temperature of the combustion device rises, the deformation of the light mixed gas passage 73 is small, and the change in the air mixing ratio is small in addition to the flow velocity, flow rate and distribution of the rich mixed gas. Therefore, in the combustion device 1 of this embodiment, the combustion of the main flame is stable.

In the above embodiment, the rich mixed gas passage section 3 is used.
Although the structure in which the metal plates are joined to each other in the middle portion of the light mixed gas flow path 73 is disclosed, when the overall structure of the combustion device is different, only the rich mixed gas passage portion 3 or the light mixed gas flow is disclosed. A configuration in which only the passage 73 is joined at the intermediate portion of the metal plate is also conceivable. For example, the combustion tube main body 2 employed in this embodiment has holes 16 and 20 on its side surface, and the rich mixed gas is discharged from the side surface of the discharging portion 13, whereas the rich mixed gas is discharged from the top portion 22 of the discharging portion 13. In such a case, it is also possible to recommend a structure in which only the rich mixed gas passage portion 3 is joined at the intermediate portion. Similarly, the total amount of the rich mixed gas released from the combustion tube body 2 is once released into the rich mixed gas passage portion 3 and the rich mixed gas is released from the rich mixed gas passage portion 3 into the mixing chamber 70 again. A configuration in which only the mixed gas passage portion 3 is joined at the intermediate portion can be recommended.

In the combustion apparatus 1 of the present embodiment, the structure in which the small projection 39 is provided on the outer surface plate 25 of the rich mixed gas passage portion 3 is disclosed. The small projections 39 are for providing a gap between the combustion devices when the combustion devices are arranged in parallel as shown in FIG. 2, and have an effect of suppressing an excessive temperature rise of the combustion devices. Further, the small projections 39 have an effect of ensuring an air flow path between the adjacent combustion devices even if the temperature of the combustion device rises and the rich mixed gas passage portion 3 is deformed. Therefore, the outer plate 2
The small protrusion 39 of No. 5 has a function of further reinforcing the effect of the present invention, and it is recommended to employ it together with the configuration of the present invention.

[0050]

As described above, in the combustion apparatus of the present invention, since the metal plates are joined at the intermediate portion, the distance between the joined portions is short. Therefore, in the combustion apparatus of the present invention, even if the temperature of the apparatus itself changes, the metal plate is difficult to bend, and the change in the cross-sectional area of the gas passage is small. Therefore, the combustion apparatus of the present invention has an effect that the combustion state does not change with the passage of time and the combustion can always be performed in a stable state.

In the combustion apparatus according to the second aspect of the present invention, the metal plate is provided with a protrusion, and the protrusion is present in the gas flow passage and divides a part of the gas flow passage, so that mixing and dispersion of the gas are promoted. It Therefore, the combustion device of the present invention has an effect that the flame distribution is uniform.

In the combustion device according to the third aspect, the rich mixed gas is directly injected from the flame holes of the supplementary flame by the rich mixed gas passage portion, and is formed between the top of the combustion tube body and the wall surface of the rich mixed gas passage portion. In the created space, the rich mixed gas is mixed with air to form a light mixed gas. Therefore, the combustion device of the present invention has a simple fuel supply system. At the same time, the combustion apparatus of the present invention is easy to assemble and construct on site. In the combustion apparatus of the present invention, a stable auxiliary flame is formed in the vicinity of the main flame, so stable combustion is possible.

Further, in the combustion apparatus of the present invention, since the three metal plates forming the rich mixed gas passage portion and the combustion tube body are joined together at the intermediate portion, the metal plate forming the rich mixed gas passage portion is The distance between the joints is short, and the amount of bending due to temperature rise is small. Therefore, in the combustion apparatus of the present invention, the cross-sectional area change of the rich mixed gas passage portion due to the temperature rise is small, and there is an effect that combustion can always be performed in a stable state. Therefore, the combustion device of the present invention has an effect of generating less NO _X. Further, in the combustion apparatus of the present invention, the combustion pipe main body and the rich mixed gas passage portion are joined at a plurality of positions, so that the mechanical rigidity is high.

In the combustion apparatus according to the fourth aspect, there is an effect of promoting the mixing and dispersion of the gas, and the flow of the gas in the rich mixed gas passage is uniform, so that the generation of the supplementary flame is uniform. There is an effect.

[Brief description of drawings]

FIG. 1 is a perspective view of a combustion apparatus according to a specific embodiment of the present invention.

FIG. 2 is a plan view of the case where the combustion device of FIG. 1 is housed in a case.

FIG. 3 is an exploded perspective view of the combustion device of FIG.

FIG. 4 is a front view (b) and a plan view (a) of a combustion tube body.

FIG. 5 is a front view (b), a plan view (a) and a rear view (c) of a rich mixed gas passage portion.

FIG. 6 is an enlarged view taken along the line AA of FIG.

FIG. 7 is an enlarged view of an end portion of FIG.

FIG. 8 is an explanatory diagram showing a manufacturing process of a concentrated mixed gas passage unit.

9 is an enlarged view of an upper end portion of the BB cross section of FIG. 5 (a).

FIG. 10 is an explanatory diagram showing a manufacturing process of the dense mixed gas passage unit.

11 is an enlarged view of a lower end portion of the BB cross section of FIG. 5 (a).

FIG. 12 is an enlarged plan view of the combustion device of FIG.

13 is an enlarged cross-sectional view of an upper end portion of the combustion device of FIG.

FIG. 14 is a development view of a flame hole member.

15 is a cross-sectional view taken along plane C of FIG.

16 is a cross-sectional view taken along plane D of FIG.

FIG. 17 is a perspective view of the combustion device with one rich mixed gas passage and the flame hole member removed.

18 is a partial cross-sectional perspective view of the combustion device of FIG.

FIG. 19 is an explanatory diagram showing a relationship between a dense mixed gas passage portion and a flame hole member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combustion device 2 Combustion pipe main body 3 Rich mixed gas passage part 5 Flame hole member 8 Front plate 9 Back plate 12 Conducting part 16 Hole 20 Hole 23 Inner surface plate 25 Outer surface plate 26 Projection (protrusion) 29 Inner wall part 31 Hole 33 Protrusion 35 Flame hole 39 Small protrusion 70 Mixing chamber 73 Light mixed gas flow path

Claims (4)

[Claims] 1. A combustion device for injecting a mixed gas of fuel and air from a flame hole to generate a flame, comprising a plurality of metal plates arranged with a predetermined gap, and the gas flow by the metal plates. Combustion device characterized in that the metal plates are joined together in the middle of the formed passage. 2. A protrusion is provided on at least one of the adjacent metal plates, the protrusion is brought into contact with the adjacent metal plate, the top surface of the protrusion is joined to the adjacent metal plate, and the protrusion forms a gas flow path. The combustion device according to claim 1, wherein the combustion device is divided. 3. A combustion pipe main body and a rich mixed gas having a combustion pipe main body for supplying a fuel gas or a high concentration fuel gas and a rich mixed gas passage portion for guiding the fuel gas or the high concentration fuel gas to a flame hole. In each of the passage portions, metal plates are arranged, and a gas flow path is formed by the metal plates.In the combustion pipe body and the rich mixed gas passage portion, the rich mixed gas passage portion protrudes beyond the top of the combustion pipe body. Are arranged in parallel, and a space that serves as a mixing chamber is formed between the top of the combustion tube main body and the wall surface of the rich mixed gas passage, and a communication hole is provided between the combustion tube main body and the rich mixed gas passage. The combustion tube body or the rich mixed gas passage part is a combustion device in which a hole for supplying a fuel gas or a high-concentration fuel gas is provided in the mixing chamber, and the combustion tube body and the rich mixed gas passage part are The ends are joined together, and the rich mixed gas Combustion device characterized in that the metal plates forming the passage part and the combustion tube body are joined together in the middle part. 4. The dense mixed gas passage portion is composed of an outer metal plate and an inner metal plate, and a protrusion protruding toward the rich mixed gas passage portion side is provided on the outer metal plate. The top surface abuts the inner metal plate, and the top surface of the protrusion of the outer metal plate and the protrusion abutting portion of the inner metal plate are integrally joined, and at the joint portion, the rich mixed gas passage portion and the combustion tube are joined. The combustion apparatus according to claim 3, wherein the main body is joined, and a communication hole that communicates the combustion tube main body and the rich mixed gas passage portion is formed immediately below the joint portion of the three members.