JP3295282B2 - Flame port plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion apparatus for injecting and burning a mixture of fuel gas and combustion air via a flame plate.

[0002]

2. Description of the Related Art Conventionally, there is a combustor provided with an incomplete combustion detecting device using a burner. Regarding such a burner, Japanese Patent Laid-Open No. 7-190347 describes that
A technique relating to a flame port plate is described as well as a technique for detecting incomplete combustion.

[0003] An example of this will be described. FIG. 6 shows a schematic configuration of a burner for detecting incomplete combustion (hereinafter, referred to as a sensor burner). The sensor burner 61 is a forced exhaust type (FE
Formula) This is installed adjacent to the main burner in the combustion chamber of the gas water heater, and changes the flame sensitively to the change in the amount of air. The gas supply is stopped by the change of the flame before the main burner incompletely burns. Safety device. The sensor burner 61 is provided in a cylindrical body 2 which is arranged in a vertical direction and has an open upper end.
A premix burner 65 is constituted by a flame port plate 64 having a plurality of pores (diameter of about 2 mm or less in this embodiment) as flame ports 64a mounted in the middle of the cylindrical body 2. The upper portion (above the flame port plate 64) is a cylindrical guard 6 that prevents the contact of the secondary air. Then, the gas nozzle 20 is made to face the opening 7 of the cylindrical body 2, and the space up to the flame port plate 64 is defined as the mixing chamber 8. The opening is set. This mixture ratio (0.9) is a setting at which the combustion speed is maximized. That is, when the mixture ratio deviates from this value, the combustion speed is reduced. Flame plate 6
As shown in a sectional view and a bottom view of FIG.
It has air permeability between 4e. And flame outlet 64
As a, a large number of pores (for example, having a diameter of 0.5 mm to 2 mm) penetrating the front surface 64d and the back surface 64e are provided.

In the sensor burner 61 having the above structure,
The air-fuel mixture having a high flow rate is prevented from directly flowing out of the remaining surface 64d of the flame port plate 64 from the air-hole 64a of the pore penetrating the front and back of the flame port plate 64. Squirt like soaking. Its surface 64
Since the flow rate of the air-fuel mixture from the fuel tank d is low, the flame is formed by the surface 64d serving as a flame holding part, and the flame port plate 64
A very stable flame is formed in the vicinity of the flame outlet 64a.
In this case, the flame is a cylindrical guard 6 surrounding the flame.
Accordingly, the supply of the secondary air is interrupted, and the entire primary combustion is performed. A thermocouple 9 is attached to the cylindrical guard 6 from the lateral direction, and a heat receiving portion 9a is positioned in the flame. The thermocouple 9 is connected to a combustion controller (not shown) of the water heater, and is configured to control opening and closing of an electromagnetic valve provided in a gas passage of the main burner according to an electromotive force of the thermocouple 9. That is, it operates so as to close the gas flow path when the electromotive force of the thermocouple 9 becomes lower than the predetermined level.

[0005] When the air volume of the combustion air decreases due to blockage of the fins of a heat exchanger (not shown) or a reduction in the capacity of a fan for feeding the combustion air into the combustion chamber, the air ratio in the mixing chamber 8 decreases and the combustion speed decreases. I do. For this reason, the flame formed near the flame port 64a lifts up, and finally forms a flame at the opening at the tip end of the tubular guard 6 as shown in FIG. In other words, during the entire primary combustion, the flame reliably lifts without being affected by the secondary air with respect to the decrease in the air volume (the decrease in the air ratio). Secondary air is supplied to perform Bunsen combustion. Thus, the flame of the sensor burner 61 is quickly lifted before the main burner incompletely burns, the output of the thermocouple is reduced, and the incomplete combustion can be reliably prevented.

[0006]

However, if foreign matters such as dust and dirt are mixed in the fuel gas and the primary air for combustion, these foreign matters smaller than the flame port 64a are reduced.
a, but foreign matter larger than the flame outlet 64a
As shown in FIG. 8, the entrance of the flame outlet 64a (that is, the back surface 64e
Side) and block the entrance of the flame outlet 64a.
As the entrance of the flame outlet 64a is more and more closed, the flame outlet 64a
Since the injection of the air-fuel mixture from the air is hindered, the combustion becomes uneven, the flame becomes unstable and the flame weakens, so the electromotive force of the thermocouple 9 decreases before the surroundings become incomplete combustion, and the incomplete combustion occurs. It cannot be detected accurately. As it becomes more closed, not only the flame outlet 64a but also the ceramics 64c
The space is clogged, the air permeability between the front and back is lost, and the air-fuel mixture hardly blows out, causing a fire. If the size of the flame port 64a is increased for the purpose of passing the flame port 64a even if the foreign matter is too large, the flame holding portion becomes too small, so that the flame cannot be held and the flame becomes unstable. Occurs. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problem and to secure communication of a flame outlet and reliably maintain combustion even when foreign matters such as dust and dirt are mixed in an air-fuel mixture.

[0007]

According to the present invention, there is provided a flame port plate which forms a flame port with pores communicating between a front surface and a rear surface, and mixes a mixture of fuel gas and combustion air from a rear surface side. In the flame port plate ejected through the flame port, a projection is provided around the flame port on the back side of the flame port plate, and a groove having a width substantially the same as that of the pore is formed in the projection in a direction perpendicular to the pore. The gist is that you have done it.

[0008] According to the flame port plate having the above structure, a flame is formed by the air-fuel mixture ejected from the flame port formed by the pores communicating between the front and back sides. Then, the flame is formed on the surface of the flame plate with the combustion speed and the ejection speed of the air-fuel mixture being balanced. In such a case, refuse mixed in the air-fuel mixture,
Even if foreign matter such as dust is attracted to the entrance of the flame port and gets stuck, a projection is formed around the flame port on the back side of the flame port plate, and a groove is formed in the projection, so the front and back through the groove Communication between them is ensured. That is, the air-fuel mixture is ejected from the flame outlet, and the stable combustion of the flame is maintained without the balance between the combustion speed and the injection speed of the air-fuel mixture being lost.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In order to further clarify the structure and operation of the present invention described above, a preferred embodiment of a flame port plate of the present invention will be described below. FIG. 1 shows a schematic configuration of a sensor burner as a first embodiment. Since the sensor burner 1 differs from the sensor burner 61 described in the prior art only in the flame port plate 4, detailed description of the same portions will be omitted to avoid duplication. As shown in a perspective view and a cross-sectional view from the back side of FIG. 2, the flame port plate 4 is provided with a projection 4b around the flame port 4a on the back side of the flame port plate 4, and the projection 4b is perpendicular to the flame port 4a. A cross groove 4q having substantially the same width as the flame port 4a is formed in the direction. This sensor burner 1
Is used by being incorporated in a gas water heater as shown in FIG. FIG. 3 is a schematic configuration diagram of the inside of the combustion chamber 30 of the FE gas water heater as viewed from above. In the combustion chamber 30, a plurality of flat main burners 31 are arranged side by side, a damper 33 for adjusting a primary air amount is provided at the tip of the throat 32, and fuel gas is supplied from each gas nozzle 35 provided on a nozzle base 34. Is supplied. The gas flow path to the nozzle table 34 is provided with a proportional control valve for adjusting the capacity (burning amount) and an electromagnetic valve (not shown) for opening and closing the gas flow path. Further, a sirocco fan (not shown) is provided below the combustion chamber 30 to supply combustion air to the combustion chamber 30 to perform Bunsen combustion with the main burner 31, and a heat exchanger (not shown) is generated by the combustion heat. It is configured to heat and tap. The sensor burner 1 is provided in parallel with the main burner 31, and fuel gas is supplied from a gas nozzle 36 provided on a common nozzle base 34. Therefore, the structure is simple without providing a separate gas flow path.

When the sensor burner 1 blows out the air-fuel mixture from the flame opening 4a to form a flame, as shown in FIG.
Even if foreign matter such as dust and dirt mixed into the air-fuel mixture is attracted to and adhered to the inlet of the flame opening 4a by the flow of the air-fuel mixture, the cross groove 4q is formed in the projection 4b.
At the same time, the cross groove 4q is not closed, and the communication of the flame outlet 4a is maintained through the cross groove 4q. In other words, even in such a state, it is possible to ensure the ejection of the air-fuel mixture from the flame outlet 4a, and to maintain a stable flame without breaking the balance between the combustion speed and the injection speed of the air-fuel mixture. Then, the flame is lifted before the main burner 31 incompletely burns, so that incomplete combustion can be prevented.

Next, a second embodiment will be described. FIG.
Represents a combustion device 21 of a type in which a flame port is formed in an aluminum plate, and a lean mixture chamber 4 to which a lean mixture is supplied.
0 and a rich mixture chamber 50 to which a rich mixture is supplied are vertically divided and provided, and a top plate of the light mixture chamber 40 is a flame port plate 44. The flame port plate 44 is provided with a plurality of light-side flame ports 42 from which a light mixture is ejected and a plurality of dark-side flame ports 52 from which a rich mixture is ejected. Flame mouth 4
The projections 42b, 52
b are provided, and the protrusions 42b and 52b have
Cross grooves 42q, 52q having substantially the same width as the flame ports 42, 52 are provided in the direction perpendicular to the grooves 2, 52. A plurality of cylindrical tubes 53 communicating with the rich mixture chamber 50 are provided on a top plate 51 of the rich mixture chamber 50.
Is provided upward, and the tip thereof is a flame port plate 44.
Each is positioned so as to surround the periphery of the dark side flame port 52 on the back surface. Accordingly, the rich air-fuel mixture supplied to the rich air-fuel mixture chamber 50 is blown out from the deep-side flame opening 52. The light-side flame port 42 has a first opening 42 c communicating with the light-side mixture chamber 40 and a first opening 4 c above (downstream side).
This is a deceleration flame port formed by the second opening 42d having a diameter larger than 2c.

In the combustion apparatus 21, the rich mixture and the light mixture supplied to the rich mixture chamber 50 and the lean mixture chamber 40 are ejected from the rich side flame port 52 and the light side flame port 42, respectively, and simultaneously. Burn. In other words, the concentration combustion is performed. In this case, the light air-fuel mixture ejected from the light-side flame port 42 has a slower ejection speed than the dark side. In other words, as shown in FIG. 5, the light air-fuel mixture that has passed through the first opening 42c and reached the second opening 42d is diffused and generates a vortex. Air blowing speed decreases. That is, for the passing speed V1 in the first opening 42c,
The passing speed V2 at the second opening 42d decreases. As a result, the combustion speed and the ejection speed of the lean mixture are balanced, so that the flame holding property of the lean flame is improved, and the combustion is stabilized. Like the sensor burner 1, the combustion device 21 emits air-fuel mixture from the flame ports 42 and 52 to form a flame.
Even if foreign matters such as dust and dirt mixed into the air-fuel mixture are attracted to the inlets of the flame ports 42 and 52 due to the flow of the air-fuel mixture and adhere to each other, the cross grooves 42q and 42q are fitted to the projections 42b and 52b.
52q, the cross grooves 42q,
There is no possibility that 52q is closed, and communication between the flame outlets 42 and 52 is maintained through the cross grooves 42q and 52q. In other words, even in such a state, the flame outlets 42, 5
Thus, the air-fuel mixture is ejected from the air-fuel mixture 2 and the combustion speed of the air-fuel mixture and the injection speed are not unbalanced, so that stable flame formation can be maintained.

The embodiment of the present invention has been described above.
The present invention is not limited to these examples in any way,
It goes without saying that the present invention can be implemented in various modes without departing from the gist of the present invention. For example, the present invention can be applied to a flame plate of an all-primary pneumatic burner used for a gas stove or a table stove grill. These are made using a ceramic flame port plate with many pores,
As in the embodiment, a mixture of fuel gas and primary air for combustion is ejected from the pores and burned. Since it generates a large amount of infrared rays, it is well-heated in a gas stove, and has a feature that a table stove can well burn fish and the like to the inside. If communication of the flame outlet is obstructed by foreign matters such as dust and dust, poor combustion occurs, infrared rays are also reduced, and the characteristics of this burner are lost. By implementing the present invention, this can be prevented and the durability of the burner can be extended. In addition, the cross grooves 4q, 42b, 52 in the embodiment.
b may be shaped like a single groove 4r (slit) as shown in FIG. Also, the cross grooves 4q, 42b, 52b
The one groove 4r forms a groove from one end of the protrusion to the other end, but may be a groove formed by a recess having a predetermined length.

[0014]

As described above in detail, according to the flame plate of the present invention, even if foreign matter such as dust and dirt mixed into the air-fuel mixture is attracted to the entrance of the flame hole and adheres,
Since the communication between the front and the back is ensured through the groove, the mixture mixture is blown out from the flame opening, and the formation of the flame is maintained. Therefore, it is highly reliable and easy to use.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a sensor burner as a first embodiment.

FIG. 2 is a perspective view and a cross-sectional view of the back surface of a flame port plate as a first embodiment.

FIG. 3 is an explanatory diagram showing a combustion chamber in a state where a sensor burner is incorporated in a gas water heater.

FIG. 4 is a schematic configuration diagram of a combustion device as a second embodiment.

FIG. 5 is a sectional view of a flame port portion of a flame port plate as a second embodiment.

FIG. 6 is a schematic configuration diagram of a conventional sensor burner.

FIG. 7 is a diagram illustrating a flame of a conventional sensor burner.

FIG. 8 is a bottom view of a conventional flame port plate and a cross-sectional view of a flame port portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sensor burner 2 Cylindrical body 4,44,64 Flame plate 4a, 42,52,64a Flame port 4b, 42b, 52b Projection 5,65 Premix burner 6 Cylindrical guard 7 Opening 8 Mixing chamber 9 Thermocouple

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F23D 14/02 F23D 14/12-14/18

Claims (1)

(57) [Claims] 1. A flame port plate in which a flame port is formed by pores communicating between the front and back surfaces, and a mixture of fuel gas and combustion air is jetted from the rear surface side through the flame port. A flame port plate, characterized in that a projection is provided around the flame port on the back side of the plate, and a groove having substantially the same width as the pore is formed in the projection in a direction perpendicular to the pore.