JPH03211307A - Burner - Google Patents

Abstract

PURPOSE:To be able to form a stable, long flame by providing a fuel supply section and an air supply section on the upstream side of a cylindrical combustion cylinder and an air flow straightening section and a fuel nozzle on the downstream side of the air supply section, and, further, providing a plurality of annular mixing rings on the inner wall face of the combustion cylinder. CONSTITUTION:The constitution is that an air supply section 2 and a fuel supply section 1 are provided on the upstream side of a cylindrical combustion chamber 7, and on the down stream side of the air supply section 2 an air flow straightening section 3 and a fuel nozzle 4 are provided, and, further, on the inner wall face of a combustion cylinder 5 a plurality of annular mixing rings 6 are provided. With this constitution part of the fuel mixes with the air the flow rate of which is straightened by the air flow straightening section 3 and flows to the downstream side substantially in parallel, but near the position in the combustion chamber 7 where the mixing rings 6 are installed part of the air on the outer circumferential side flows to the inner side by the mixing rings 6, and this flow promotes the mixing of the air with the fuel or unburned gas and the combustion becomes active. Because of the plural number of the mixing rings 6 the combustion is promoted near the position where the mixing rings 6 are installed, and since in the other positions the mixing of the air with the fuel or unburned gas is slow, the combustion is slow. With this arrangement a stable, long flame can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a combustion device used in heat source equipment for heating, hot water supply, drying, etc.

2. Description of the Related Art Conventionally, as shown in FIG. 2, this type of combustion apparatus has a cylindrical combustion chamber 8 provided with a nozzle portion 9 and an air swirling portion 10, and fuel ejected from the nozzle portion 9 and supplied from the air swirling portion IO. There is a diffusion type, in which a part of the air necessary for combustion is mixed with fuel and combusted, and a pre-fueled type, in which a part of the air necessary for combustion is mixed with fuel and ejected from the nozzle part 9, and further mixed with air supplied from the air swirling part 10 and combusted. Mixed types are often used.

In the above configuration, the swirling flow of air formed in the air swirling section 10 promotes mixing of fuel and air, and a relatively short flame is formed in the combustion chamber 11 for combustion.

Problems to be Solved by the Invention In such conventional combustion devices, the air swirling section was provided at the upstream part of the combustion chamber. It is mixed with
As it moves downstream, the swirling force decreases and the mixing capacity decreases. Therefore, it is suitable for combustion with a short flame with a strong swirling force, but when burning with a weak swirling force and a long flame, unburned gas and air are mixed downstream in the combustion chamber. There was a problem that it deteriorated and easily generated soot and CO.

The present invention solves the above problems, and aims to provide a combustion device that generates less soot and CO in a cylindrical combustion chamber and forms a long flame.

Means for Solving the Problems In order to achieve the above object, the present invention provides an air supply section and a fuel supply section on the upstream side of a cylindrical combustion chamber, and an air rectification section and a fuel nozzle on the downstream side of the air supply section. The combustion device has a configuration in which a plurality of annular mixing rings are arranged on the inner wall surface of the combustion cylinder.

According to the above-described structure, the fuel flows almost parallel to the downstream side while being partially mixed with the air rectified by the air rectifier and combusted. A portion of the air on the outer circumferential side flows inward, promoting mixing with fuel or unburned gas and activating combustion. Because multiple mixing rings are provided, combustion is promoted near the mixing ring installation position, and at other locations, mixing with fuel or unburned gas is slow, resulting in slow combustion and a long flame. It is something that can be formed.

Embodiment Below, an embodiment of the present invention will be explained with reference to FIG. 1.As shown in FIG.
It is connected to the upstream side of the fuel tank to supply fuel. The air supply section 2 is also connected to the upstream portion of the combustion tube 5 to supply air necessary for combustion. An air rectifying section 3 is provided downstream of the air supply section 2 . This air rectifying section 3 is configured in a lattice shape in order to rectify the air. The fuel nozzle 4 is located on the downstream side of the air straightening section 3 of the combustion tube 5, and is configured to inject fuel into the combustion chamber. The combustion cylinder 5 is formed in a substantially cylindrical shape, and has a plurality of annular mixing rings 6 on its inner wall surface, and a combustion chamber 7 is formed in the internal space.

Further, among the plurality of mixing rings 6, the inner diameter of the one on the most downstream side is made smaller than the inner diameter of the other mixing rings.

To explain the operation of the above configuration, when fuel is supplied from the fuel supply section 1 and air is supplied from the air supply section 2, the fuel is ejected from the fuel nozzle 4 into the combustion chamber. The air is rectified as it passes through the air rectifying section 3 and is supplied into the combustion chamber 7 in substantially parallel flows.

The fuel supplied from the fuel supply section 1 at this time may be mixed with a portion of the air necessary for combustion in advance.

When the fuel ejected from the fuel nozzle 4 is ignited, a flame A is formed with the tip of the fuel ejection nozzle 4 as the base. On the upstream side of the combustion chamber 7, the air flows almost parallel to the flame A as shown by arrow B, so the mixture of fuel and air is poor, combustion is slow, and the flame A expands. In the vicinity of the installation location of the mixing ring 6, the flow of air is deflected by the mixing ring 6 toward the flame A as shown by arrow C, and mixing with the unburned gas in the flame A is promoted, resulting in active combustion. . Below 'fL@' of the lowest stage mixing ring 6, the remaining air becomes parallel again (arrow B'), so that combustion becomes slow. As described above, combustion is active in the vicinity of the mixing ring 6 and slow in other locations, and combustion is completed by repeating this cycle.

Further, the length of the flame A can be adjusted by adjusting the inner diameter of the mixing ring 6. In other words, if the inner diameter of the mixing ring 6 is made smaller, the deflection of the air becomes larger and the air diffuses to the inside of the flame A, which in turn activates combustion, shortens the flame length, and increases the flame temperature in the vicinity of the mixing ring 6. .

Furthermore, the concentration of unburned gas in the flame A becomes dilute as it goes downstream, making combustion difficult; however, by reducing the inner diameter of the mixing ring 6 on the downstream side, air can diffuse into the flame. Therefore, it is possible to achieve almost complete combustion, and the generation of soot and CO can be prevented.

As described above, according to the combustion apparatus of the embodiment of the present invention, by selecting the inner diameter, the number of installations, and the installation position of the mixing ring 6,
Since the flame length can be arbitrarily set and the flame temperature can be partially adjusted, the wall surface of the long combustion tube 5 can be heated to a substantially uniform temperature.

Effects of the Invention As is clear from the above embodiments, according to the present invention, a fuel supply section and an air supply section are provided on the upstream side of a cylindrical combustion cylinder,
By providing an air rectifying section and a fuel nozzle on the downstream side of the air supply section and providing a plurality of annular mixing rings on the inner wall surface of the combustion cylinder, the following effects can be obtained.

1) It is possible to form a stable and long flame that does not easily generate Co or soot.

2) A long heating surface with almost uniform temperature can be created.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a combustion apparatus according to an embodiment of the present invention, and FIG. 2 is a sectional view of a main part of a conventional combustion apparatus. l... Fuel supply section, 2... Air supply section, 3... Air rectification section, 4... Fuel nozzle, 5...... Combustion cylinder, 6... Mixing ring, 7... Combustion chamber.

Claims (2)

[Claims] (1) A fuel supply section and an air supply section are provided on the upstream side of the cylindrical combustion tube, and an air rectification section and a fuel nozzle are provided on the downstream side of the air supply section, and an annular shape is provided on the inner wall surface of the combustion tube. Combustion device with multiple mixing rings. (2) The combustion apparatus according to claim 1, wherein the inner diameter of the mixing ring provided most downstream is smaller than the inner diameter of the other mixing rings.