JPH01147207A - Burner - Google Patents

Abstract

PURPOSE:To reduce the discharge of NOx with a flame that does not generate CO and unburnt gases and is stable by providing secondary air supply holes opposite to respective flame holes in a secondary air supply section in the shape of a doughnut which is provided on the outside of a burner head concentrically with the burner head. CONSTITUTION:A secondary air supply section 16 is provided which is in the shape of a doughnut and arranged concentrically with a burner head 13 on its outside. The secondary air supply section 16 is provided with small secondary air supply holes 17 which are small and have a diameter smaller than a flame hole 14 at the position opposite to each of the flame holes 14. By the function of the secondary air that is jetted out from secondary air supply holes 17 the flames formed by the flame holes 14 are cooled with the tip of the flame with the highest temperature as the center so that the flame temperature drops, reducing the amount of generated NOx. Because the direction of jetting of the mixture gas that is jetted out from the flame hole 14 and the direction of jetting of the secondary air that is jetted out from the secondary air supply hole 17 is opposite to each other, the flames are hydrodynamically stable. And, because the diameter of the secondary air supply hole 17 is smaller that of the flame hole 14, the cooling of the flame base which is vital for flame holding is avoided, making the flame stable.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a combustion device used in a heater or the like.

BACKGROUND OF THE INVENTION In recent years, there has been a demand for combustion equipment that uses oil, gas, etc. as a combustion material, and has better exhaust gas characteristics due to problems such as indoor pollution and air pollution. An example of such combustion requirements will be described below with reference to FIG. 3. Reference numeral 1 denotes a bottomed cylindrical vaporizing cylinder, and the inside thereof is a mixing section 2 for vaporizing fuel and mixing it with air. Reference numeral 3 denotes a cylindrical burner head attached above the opening of the vaporization cylinder 1, and a plurality of approximately small flame holes 4 are provided in the peripheral wall of the burner head. 5 is a burner lid that covers the upper part of the burner head 3 and is closely fixed to the burner head 3. A burner ring 6 is provided on the outside of the burner head 3 and is arranged concentrically so as to face the flame hole 4.
A secondary air supply hole 7 is provided so that a portion of the secondary air enters from below.

The operation of the combustion apparatus configured as described above will be explained below. First, fuel vaporized in the vaporization tube 1 and combustion air are premixed in the mixing section 2, and the resulting mixed gas flows into the burner head 3 provided on one side of the opening of the vaporization tube 1. Since the upper part of the burner head 3 is covered and sealed by the burner lid 5, this mixed gas is ejected from the flame holes 4 provided in the peripheral wall of the burner head 3, forming Otomo. The flame formed in this flame hole 4 is completely filled with a part of the secondary air flowing in from the secondary air supply hole 7 provided at the bottom of the burner ring 6 and the remaining secondary air flowing outside the burner ring 6. Perform combustion.

Problems to be Solved by the Invention However, in the above configuration, since the X+ formed by the flame hole 4 is surrounded by the burner ring 6 on the outside, the flame temperature becomes extremely high. Therefore, the value of NOx shows a very high value. Furthermore, if a large amount of secondary air is introduced through the secondary air supply hole 7 at the bottom of the burner ring 6 in order to lower the flame temperature, the flame becomes extremely unstable and CO and unburned gas are emitted due to the lift phenomenon. cause.

From the above, in order to achieve stable combustion without the generation of CO and unburned gas, it is necessary to limit the amount of secondary air, and as a result, the flame temperature cannot be lowered. There was a problem in that the NOx value was high.

The present invention solves the above-mentioned problems, and uses a stable flame that does not generate CO or unburnt gas to reduce NOx.
The objective is to provide a safe combustion device with good exhaust gas characteristics that reduces emissions.

Means for Solving the Problems In order to achieve the above object, the combustion apparatus of the present invention has a donut-shaped secondary air supply section arranged concentrically outside the burner head, and this secondary air supply section is arranged concentrically outside the burner head. The secondary air supply hole is provided at a position opposite to each of the flame holes.

Effect of the present invention With the above configuration, the secondary air ejected from the secondary air supply hole can be cooled mainly at the tip of the flame formed in the flame hole, where the temperature is highest, and the flame temperature can be considerably reduced. do. Furthermore, since the direction of the mixed gas ejected from the flame hole and the ejection direction of the secondary air ejected from the secondary air supply hole are opposite to each other, the flame becomes extremely stable from a hydrodynamic perspective.

Therefore, with the above configuration, it is possible to reduce NOx emissions by 5... with a stable flame that does not generate CO and unburned gas, resulting in a safe combustion device with good exhaust gas characteristics.

EXAMPLE An example of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, reference numeral 11 denotes a bottomed cylindrical vaporizing cylinder, and the inside thereof serves as a mixing section 12 for vaporizing fuel and mixing it with air.

Reference numeral 13 denotes a cylindrical burner head attached above the opening of the vaporization cylinder 11, and a plurality of approximately small flame holes 1 are provided in the peripheral wall of the burner head.
4 is provided. A burner 7 15 covers the upper part of the burner head 13 and is tightly fixed to the burner head 13 . 16 is a donut-shaped secondary air supply section arranged concentrically outside the burner head 13;
This secondary air supply section 16 is provided with substantially small-hole-shaped secondary air supply holes 17 having a smaller diameter than the flame holes 14 at positions facing each of the flame holes 14 .

Next, the operation of the above configuration will be explained. First, the fuel vaporized in the vaporization tube 11 and the combustion air are mixed into the mixing section 12.
The mixed gas is vaporized and flows into the burner head 13 provided above the cylinder 11. This mixed gas is connected to the upper part of the burner head 13 by the burner lid 1.
5, the mixed gas is ejected from the flame hole 14 provided in the peripheral wall of the burner head 13 to form a flame.

Here, in this combustion device, on the outside of the burner head 13,
Secondary air supply holes 1 are provided at positions facing each of the flame holes 14.
7, the flame formed in the flame hole 14 is cooled mainly at the tip of the flame, which has the highest temperature, by the secondary air jetted out from the secondary air supply hole 17. Can be done. Therefore, the flame temperature decreases and N
Ox emissions are reduced. Moreover, since the jetting direction of the mixed gas jetting out from the flame hole 14 and the jetting direction of the secondary air jetting out from the secondary air supply hole 17 are opposite, the flame becomes extremely stable from a hydrodynamic perspective. .

In addition, since the diameter of the secondary air supply hole 17 is smaller than the diameter of the flame hole 14, it is possible to avoid cooling the flame base, which affects the flame stability of the flame, making the flame even more stable. It is said that

7.\-/ From the above, the flame is very stable, and the CO
Lift combustion, which causes the generation of unburned gas, can be prevented.
Furthermore, the amount of NOx emissions can be reduced due to the reduction in flame temperature.

Effects of the Invention As is clear from the description of the embodiments, according to the present invention, C
With a very stable flame that does not generate O or unburned gas, N
Ox emissions can be reduced, and a safe combustion device with good exhaust gas characteristics can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a combustion device according to an embodiment of the present invention, FIG. 2 is a sectional view of the same combustion device, and FIG. 3 is a sectional view of a conventional combustion device. 12...Mixing section, 13...Burner head, 14...Flame hole, 16...Secondary air supply section, 17...2 Next air supply hole. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 7? - 11 mud shunto 13 - 11 barbhed ti - 11 flame charge tb ---z Next a nmuhei co-groove image (151'7
---2 water left air filter 1 supply/hole

Claims (2)

[Claims] (1) Equipped with a mixing section that mixes air and fuel, and a burner head that burns the mixed gas from the mixing section through a plurality of approximately small flame holes provided on the outer peripheral wall of the mixing section, and A combustion device comprising a donut-shaped secondary air supply section arranged substantially concentrically, and a substantially small-hole-shaped secondary air supply hole provided at a position facing each of the flame holes of the secondary air supply section. (2) The combustion device according to claim 1, wherein the secondary air supply hole has a smaller diameter than the flame hole.