JP2956215B2 - Combustion equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low NOx burner combustion apparatus mainly used for home use.

[0002]

2. Description of the Related Art Conventionally, this type of household burner includes a first air-fuel mixture chamber 3 provided in a burner main body 2 having a first flame opening 1 as shown in FIG. A second air-fuel mixture chamber 6 having a second flame port 5 constituted by wall plates 4 on both sides of the air chamber 3 is communicated with the first air-fuel mixture chamber 3 and the second air-fuel mixture chamber 6. A mixture passage 7 provided in the burner main body 2, a flame stabilizing plate 8 provided between the first flame port 1 and the second flame port 5 for stabilizing a flame base, and a wall plate 4 And an air inlet 9 for setting the primary air ratio of the second mixture chamber 6.

In such a configuration, the first flame port 1
A rich flame with low oxygen concentration is formed on the flame. Further, a large amount of air sucked from the air intake port 9 and the mixture supplied from the mixture path 7 become a lean mixture outside the flammable limit inside the second mixture chamber 6, and the second flame port 5 and burned under the thermal influence of the rich flame to form a lean flame with a high oxygen concentration. The base of the flame of the rich flame and the lean flame is stabilized by the flame stabilizing plate 8, and as a whole, the light and dark combustion is realized to reduce the generation of NOx.

[0004]

However, the above structure is satisfactory in terms of the effect of reducing NOx, but as the amount of combustion is reduced, the first flame port 1 is reduced.
In addition, the air-fuel mixture jet speed spouted from the second flame outlet 5 is reduced. In particular, if the amount of supplied air decreases, the mixing inside the second mixture chamber 6 falls within the flammable range,
There is a problem that the lean flame returns to the outlet of the air-fuel mixture passage 7 through the second flame port 5 and abnormally heats the burner main body 2 and the wall plate 4.

The present invention solves the above-mentioned conventional problems. The present invention reduces the NOx in the exhaust gas, increases the TDR by preventing a flashback of the flame to the outlet of the air-fuel mixture passage, improves the durability of the burner, in addition and noise reduction due to stabilization of the flame, one
An object of the present invention is to realize a combustion device capable of reducing NOx in a bed .

[0006]

To solve the above-mentioned problems, a combustion apparatus according to the present invention comprises a first air-fuel mixture chamber provided in a burner body having a first flame port, and a first air-fuel mixture chamber. A second air-fuel mixture chamber surrounded by an auxiliary plate on the side of the chamber,
An air-fuel mixture passage provided in the burner main body communicating the first air-fuel mixture chamber and the second air-fuel mixture chamber, and an air intake opening for setting a primary air ratio of the second air-fuel mixture chamber provided in the auxiliary plate When, a second flame port portion comprising a number of small auxiliary plate on the side of the first flame opening, less between the second flame port portion and the first flame opening
And a horizontal mouthless portion.

[0007]

According to the present invention, a lean air-fuel mixture outside the flammable range is ejected from the second flame port by the above-described structure, and is subjected to the thermochemical action of the flame formed on the first flame port. performing low NOx combustion is stabilized by. When the amount of combustion decreases or the amount of supply air decreases, a mixture in a low-speed flammable range is ejected from the second flame port. At this time, since the second flame port portion is composed of a number of small holes, the lean flame does not flash back to the air-fuel mixture passage and forms a flame on the small hole. In addition, a small circulation area of the air-fuel mixture is formed on the horizontal mouthless part, and flame holding is performed physically, and thermochemical action and
The synergistic effect is exhibited.

[0008]

An embodiment of the present invention will be described below with reference to the accompanying drawings. The same components are denoted by the same reference numerals.

In FIG. 1 to FIG. 3, reference numeral 2 denotes a burner main body containing a first air-fuel mixture chamber 3, and a first flame opening 1 having a large number of slits formed on an upper surface of the burner main body 2. On both side surfaces of the burner main body 2, mixture passages 7 are provided at optimal intervals in the longitudinal direction. On both side surfaces of the burner main body 2, auxiliary plates 10 forming opposed second mixture chambers 6 are attached. A large number of foreheads 11 are provided at the upper end of the auxiliary plate 10.
A second flame port portion 12 made of more, less between the burner body 8
At least a mouthless portion 13 having a horizontal direction is formed and connected to the burner main body 2. At the lower part of the auxiliary plate 10, air inlets 9 are provided at optimal intervals in the longitudinal direction of the burner main body 2, and are connected to the burner main body 2. On the upstream side of the burner main body 2, a throat portion 14 is formed,
A plurality of such burner bodies 2 are provided side by side to form a burner block, and are housed inside the burner case 15.
Nozzle 16 for ejecting fuel facing each throat portion 14
And a fan 18 are connected to the burner case 15.

In the above configuration, a part of the combustion air supplied from the fan 18 flows into the burner main body 2 from the throat portion 14, and most of the remaining air flows between the burner main bodies 2 to take in air. The gas flows into the second mixture chamber 6 from the port 9. On the other hand, the fuel supplied from the fuel pipe 17 is
The fuel is ejected from each nozzle 16 toward each throat portion 14, flows into the burner main body 2, and is mixed in the first air-fuel mixture chamber 3. The mixture in the first mixture chamber 3 has a primary air ratio of 30 to 60%. A part of this air-fuel mixture blows out from the first flame opening 1 to form a rich flame, and most of the remaining air-fuel mixture flows from the air-fuel mixture passage 7 to the second air-fuel mixture chamber 6
And mixed with a large amount of air entering through the air intake 9. At this time, the primary air ratio was changed from 170 to 25.
The mixture becomes a lean gas mixture of about 0% and out of the flammable range and is made uniform, and is ejected from the small port 11 of the second flame port 12 to form a lean flame. The remainder of the combustion air is supplied to the auxiliary plate 10
Of the first burner port 1 and the cooling of the burner case 15. Here, the amount of thermal NOx generated decreases as the temperature of the flame reaction zone decreases. Therefore, as the air-fuel mixture contains a large amount of air, the heat capacity increases and the flame temperature decreases,
It is well known that NOx can be reduced. However, on the other hand, the flame becomes unstable as the air-fuel mixture becomes lean, and eventually, a blow-off occurs. Therefore, in the above configuration, the thermochemical action of the rich flame formed on the first flame opening 1
The lean flame is stabilized by the synergistic effect of the flame holding effect and the flame holding effect due to the physical action of the small vortex formed on the horizontal mouthless portion 13, so that the low NOx is obtained as a whole burner block.
Realize combustion.

When the amount of combustion decreases, the flow velocity of the air-fuel mixture ejected from each flame opening decreases, and the flame approaches the flame opening. Further, if the supply air amount fluctuates, the amount of combustion is small, so that the air-fuel mixture inside the second air-fuel mixture chamber 6 may enter the flammable range. At this time, the lean flame proceeds inside the second mixture chamber 6, but the flame 11 flashes back inside the second mixture chamber 6 because the hole 11 can be made smaller in diameter than the quenching diameter. To prevent Therefore, stable combustion can be obtained even if the amount of combustion is reduced.

[0012]

As described above, according to the low NOx burner of the present invention, the following effects can be obtained. 1) Low NOx is realized by burning most of the fuel with a lean flame having a low flame temperature formed on the second flame port. In addition, the inherently unstable rare flame has a flame holding effect due to the thermochemical action of the rich flame formed on the first flame orifice and the physical effect of small vortices formed on the horizontal mouthless part.
The stable combustion can be performed by the synergistic action of the flame holding effect by the action, so that the stable combustion range is expanded. 2) Since the second flame port is provided with a small port having a diameter smaller than the extinction diameter, even if the amount of combustion is small and the flame approaches the second flame port, the second mixture chamber is formed. It is possible to prevent the flame from flashing back into the air-fuel mixture passage through the gas passage, and therefore, it is possible to increase the variable width (TDR) of the combustion amount. 3) Since the auxiliary plate is provided with a portless portion, a small port, and an air intake port, and the second air-fuel mixture chamber is formed between the auxiliary plate and the burner main body, the number of parts is reduced and the device can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a sectional perspective view of a main part of a combustion apparatus according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing a flame state formed when the combustion apparatus has a large combustion amount.

FIG. 3 is a partial cross-sectional view showing a state of a large flame formed when the combustion device has a small combustion amount.

FIG. 4 is a sectional perspective view of a main part of a conventional combustion device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st flame mouth part 2 Burner main body 3 1st air-fuel mixture chamber 6 2nd air-fuel mixture chamber 7 air-fuel mixture passage 9 air intake 10 auxiliary plate 11 small opening 12 2nd flame opening 13

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-151408 (JP, A) JP-A-2-115627 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F23D 14/02-14/10 F23C 11/00 329-330

Claims (1)

(57) [Claims] 1. A first air-fuel mixture chamber provided in a burner body having a first flame opening, and a second air-fuel mixture chamber formed by an auxiliary plate provided on a side of the first air-fuel mixture chamber. An air-fuel mixture chamber, an air-fuel mixture passage provided in the burner main body communicating the first air-fuel mixture chamber and the second air-fuel mixture chamber, and a second air-fuel mixture chamber provided in the auxiliary plate. An air inlet for setting a primary air ratio, a second flame port provided on a side of the first flame port and having a number of small holes formed in the auxiliary plate, and the second flame port At least water between the part and the first flame port
A combustion device with a flat mouth.