JPS607178B2 - combustion device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a combustion device having a slit-shaped flame port.

In a combustion device in which a large number of slit-shaped flame ports are arranged side by side at intervals so that their longitudinal directions are parallel, when the ratio of air in the mixture is reduced, the flame becomes a diffusion flame, which swells and spreads between the flames. As the interval becomes smaller, the inflow of combustion air tends to become worse. The present invention aims to solve the above-mentioned problems and improve the combustibility by improving the mixing with the combustion air.The present invention aims to improve the combustibility by improving the mixing with the combustion air. and a mixing board is installed so that the tip of the flame port protrudes an appropriate length,
Combustion air passages are provided corresponding to both longitudinal ends of the flame opening, and the mixing plate has an air hole approximately in the center between the slit-shaped flame openings, the total opening area of which is smaller than the area of the combustion air passage. It is.

An embodiment of the present invention will be described below based on the drawings. 1st
In the figures and FIG. 2, reference numeral 1 denotes a burner head for supplying fuel, and a large number of slit-shaped flame ports 2 are arranged in parallel at intervals t so that their longitudinal directions are parallel. 3 is a burner case in which combustion air passages 4 are set on both sides of the burner head 1 and corresponding to both longitudinal ends of the slit-shaped flame ports 2; 5 is a burner case approximately at the center of the many slit-shaped flame ports 2 arranged in parallel; The spark plug 6 provided in the section is an air supply □ that is connected to the fan motor to supply combustion air.

Reference numeral 7 denotes a fuel gas supply port, and the fuel injected here is guided to the burner head 1 and distributed to each flame port 2.

Reference numeral 8 denotes a mixing plate, and the tip of the slit-shaped flame port 2 is provided to protrude from the mixing plate 8 by an appropriate length.

When one of the IJ slot-shaped flame ports 2 is ignited through the ignition plug 5 and a flame 9 is formed, this flame 9 is transferred one after another to the other flame ports 2 arranged in parallel. 101 is an air hole provided approximately in the center between the slit-shaped flame ports 2 of the mixing plate 8.

Next, the flow form of secondary air will be described.

When fuel is ejected from each slit-shaped flame port 2 and a flame 9 is formed, a negative pressure is created at the interval t between the flame ports 2, and this negative pressure is more pronounced toward the center. Therefore, a large pressure difference is generated between the combustion air passage 4 passed through the fan motor, and at the side edge of the mixing plate 8, part b of the combustion air a rising through the combustion air passage 4 is At the upper surface of the mixing plate 8, the direction is changed at right angles as shown in FIG. Generally speaking, intermittent flow occurs between two flames and between the flame and combustion air due to the generation of Karman vortices.
As described above, by flowing the combustion air in the perpendicular direction, the generation of Karman vortices can be prevented and the combustion air can be continuously introduced. This flow is two turbulent flows as shown in Figure 3.
This is mixed with a portion of the fuel and dispersed in a turbulent flow at the base of the flame, resulting in stable combustion. Now, when the tip of the slit-shaped flame nozzle 2 and the mixing plate 8 are on the same plane or when the protruding part of the flame nozzle 2 is small, the flame becomes a diffusion flame when the proportion of air in the mixture is reduced, and as it swells, the interval between the flames becomes t. than 4
・It tends to become thinner.

Therefore, the inflow of combustion air becomes poor and red flames are likely to occur.
Secondary flame tends to be long. It is preferable that the distance t is larger than the distance s inside the slit-shaped flame opening 2 so that combustion air can easily enter between the flames 9.

However, if the interval t becomes too large, turbulent flow will hardly occur in the area of the interval t, and turbulent flow diffusion will not occur. Therefore t
< About $1 is good. Further, the length of the protruding portion of the flame port 2 from the mixing plate 8 is approximately s. Here, since the flame port 2 protrudes above the mixing plate 8, the secondary air passage becomes an area surrounded by the flame port 2 and the mixing plate 8, and a constant blow of combustion air is generated regardless of the swelling of the flame 9. can be done. Furthermore, since an air hole 10 is provided in the mixing plate 8 approximately in the center between the flame ports 2, the secondary air is sucked through the air hole 10 by a negative pressure of an interval t, as shown in FIG. Since the secondary air is not forcibly sent out but is sucked in by negative pressure, the secondary air is sucked from the longitudinal direction of the burner port 2 between the air hole 10 and the burner port 2 as shown in FIG. Since the secondary air can be sent out without interfering with the inflow of the secondary air, it is possible to improve the mixing with the air-fuel mixture, increase flame stability, and prevent the occurrence of red flames etc. by increasing the amount of secondary air.

If the total area of the air holes 10 is not smaller than the combustion air passage 4, the combustion air will be forced out, and the steady flow of the two secondary airs with the interval t will become unstable. The flames become chaotic. As described above, according to the present invention, the mixing property of the secondary air with the flame is extremely good, and thereby good combustion characteristics can be obtained.

Furthermore, since the mixing properties of the secondary air are good, it is possible to improve the flame transfer properties at the time of ignition.

[Brief explanation of the drawing]

1 and 2 are a plan view and a partially cutaway side view showing one embodiment of the present invention, FIG. FIG. 4 is an explanatory diagram illustrating the state of the secondary air flow from the air holes provided in the mixing plate. 1...burner head, 2...slit-shaped flame opening, 4...
... Combustion air passage, 8... Mixing plate, 10...
・Air hole. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A large number of slit-shaped flame ports are arranged side by side at intervals so that their longitudinal directions are parallel, and a mixing plate is installed so that the tips of the flame ports protrude by an appropriate length, and the longitudinal direction of the flame ports is A combustion device characterized in that combustion air passages are provided corresponding to both ends in the direction, and the mixing plate has an air hole approximately in the center between the slit-shaped flame ports, the total opening area of which is smaller than the area of the combustion air passage.