JPS61217613A - Premixing gas burner - Google Patents

Abstract

PURPOSE:To form opposing flames at a right angle with a flat surface to a flame port and to form stable flames without change by a method wherein a side wall provided on the flame port is opposed by a fixed distance through an air cap and the side wall is projected from the flame port part. CONSTITUTION:Flame ports 8, 9 are opposed with an air gas 16 between them are premixing gas is ejected from the opposed flame, ports to collide in the air gap. The premixing gas ejected from the opposed flame ports 8, 9 to a combustion chamber is ignited and the opposing flames 17 is formed, at this time, the stable opposing flames are formed in case the premixing gas 12, 13 are laminar flow. A stagnation point 20 between two flame surfaces of the opposing flame is formed, flow speed at the stagnation point is zero in ideal, the flow speed is small in this neighboring. The stagnation thereof may be contributed to the stable opposing flame 17.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a premixed gas burner used as heating equipment for industrial, commercial or domestic use.

Conventional technology Conventionally, gas burners have used radiant heat, such as schbank burners, or slit burners or wire mesh burners with flame ports made of metal or metal to reduce the amount of Noz emissions from combustion exhaust gas. It used a premix combustion method.

Problems to be Solved by the Invention Gas burners that utilize such premixed combustion have often been used with an air ratio (E) of 1 or more, as shown in the formula disclosed in the Examples section. As a result, the fuel flow rate, that is, the range in which the combustion amount can be varied, is narrow, and the burner burns at a constant combustion heat. Therefore, such burners have a small turn-and-burn ratio, and when you want to change the combustion heat, must be used repeatedly by extinguishing or igniting the burner,
They were difficult to use, consumed a lot of fuel, and had problems in terms of energy efficiency.

Therefore, as shown in FIG. 3, an attempt was made to make the flame port 1 and the flame port 2 face each other at a certain distance to form an opposing flame a. At this time, the premixed gases 4 and 6 ．． This method makes it possible to widen the variable range of combustion amount, but as shown in Figure 3, the opposing flames may deform or fluctuate, resulting in problems with flame stability. Therefore, a sufficient range of combustion phosphorus amount variation cannot be obtained.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention has provided a method in which the side walls provided with the burner ports are arranged to face each other at a fixed distance through a gap, and the burner ports also protrude from the sidewalls. This is a premixed gas burner with special features.

Operation According to the above configuration, the opposing flame is formed in a planar shape in a direction perpendicular to the flame port, and a stable flame without fluctuation is formed. Therefore, the combustion variable range could be expanded sufficiently.

Embodiment FIG. 1 is a perspective view showing an embodiment of the present invention.
10 and 11 are side walls, 12.13 is a premixed gas that is a mixture of fuel gas and air, and 14.15 is a premixed gas inlet. The side walls 10° and 11 are arranged in parallel with the space [16] interposed therebetween. The premixed gases 12 and 13 are supplied from the premixed gas inlet to the flame nozzle 8°9.
The flame ports 8 and 9 face each other with a gap 16 in between, and the premixed gas is ejected from the opposing flame ports and collides within the gap. The flame ports 8 and 9 are rectangular or slit-shaped flame ports, as shown in FIG. The mixed gas collides with the premixed gas ejected from the respective opposing flame ports.

17 is an opposing flame, which is composed of two opposing planar flame surfaces 18 and 19. 2o is the stagnation point. When the premixed gas ejected into the combustion chamber from the opposing flame ports 8 and 9 is ignited, opposing flames 17 are formed. At this time, if the premixed gases 12 and 13 are in a laminar flow, stable opposing flames are formed. A stagnation point 2o is formed between the two flame fronts of the opposing flames. Ideally, the flow velocity at the stagnation point is 0, and the flow velocity near this point is small. This stagnation point contributes to the stability of the opposing flame 17 ◎ The gas burner of the present invention uses premixed gas, and if the air ratio is large and the amount of combustion heat is small, there is a risk of backfire. The flame openings 8 and 9 are often made smaller than the extinguishing distance. Therefore, the thickness of the flow of the premixed gas ejected from the slit-shaped flame ports 8 and 9 as shown in Fig. 3 is thin, and there is a slight difference in the flow velocity of the premixed gas from the opposing flame ports. is deformed and tends to cause combustion instability. In the present invention, the premixed gas flows perpendicularly to the direction of the flame nozzle. Therefore, like the premixed gas, a stable flat flame is formed without deformation in the direction perpendicular to the flame nozzle. At this time, Since the flame port protrudes from the side wall, the flame comes into contact with the side wall, and there is no discharge of unburned gas due to cooling.

It maintains a flat surface and forms a stable flame.

FIG. 2 shows the stable combustion region of the gas burner shown in FIG. 1, which is an embodiment of the present invention. The solid line shows the blow-off limit and extinguishing limit of the conventional slit burner. The stable combustion region is indicated by diagonal lines. The broken line indicates the blow-off limit and extinguishing limit of the present invention. The region surrounded by the broken line is the stable combustion region, and includes the stable combustion region of the slit burner. The blow-off limit extends to areas where the air ratio is high and the flow velocity is high.

Furthermore, the extinguishing limit also extends to the region of low flow velocity. The horizontal axis is the air ratio (e), and the vertical axis is the flow rate of the premixed gas at the long-day outlet. air ratio) is shown by the following formula.

The flow velocity V is a relative value when the flow velocity during flame extinguishing when m = 1 is 1 ◇ If the flame ports 8 and 9 are smaller than the flame extinguishing distance, reducing the flow rate of the premixed gas will cause flame extinguishment at the flame mouth. . Extinction is caused by heat loss from the flame to the burner or air gap. In the burner of the present invention, since the flame is surrounded by the side wall, heat loss to the air gap is small, making it difficult to extinguish the flame. The same effect can be obtained even if multiple flame ports are facing each other. At this time, dividing the flame port helps prevent backfire.

Effects of the Invention The present invention provides a burner with a large TDR through premix combustion by making the side walls provided with a flame port face each other at a fixed distance with a gap in between, and making the side walls protrude from the flame port.■ Air ratio Since combustion is possible in a large area of

[Brief explanation of drawings]

FIG. 1 is a perspective view of essential parts of a gas burner according to an embodiment of the present invention;
FIG. 2 is a perspective view of a main part of a conventional gas burner, and FIG. 3 is a diagram showing a stable combustion region of the gas burner. 8.9...flame mouth, 10,11・river...side wall, 1
6... air gap, 17... opposing flame. Name of agent: Patent attorney Toshio Nakao and one other person8.
9-11 Moxibustion mouth and O Fig. 2

Claims (2)

[Claims] (1) A premixed gas burner characterized in that side walls provided with a flame port are opposed to each other at a constant distance through a gap, and the flame port is made to protrude beyond the side wall. (2) The premixing according to claim 1, characterized in that side walls provided with a row of burner ports arranged at a predetermined interval are opposed to each other with a gap in between, and the burner port portions protrude from the side walls. gas burner.