JPH0240407A - Burner - Google Patents

Abstract

PURPOSE:To make it possible to change the form of flame from the diffusion flame to the pre-mixing flame and provide a burner which is able to perform a high TDR (turn down ratio) combustion by providing in the inside and outside flame holes each with a flange with their heights changed and taking air into the flame holes which are inside. CONSTITUTION:An air straightening plate 3 which has many air supply holes 2 on the lower side of an air chamber 1 is provided, and above the air straightening plate 3 a fuel supply pipe 4 with a flame hole with a flange face 6 opened on its upper end is provided. In the outside of the fuel pipe 4 a mixing pipe 7 with flange faces 9 as the pipe 4 and a large flame hole 8 larger than the flame hole 5 opened at the upper end is provided, and at a position below the mixing pipe 7 a plurality of air holes 10 are provided. The flame hole 5, large flame hole 8, and the upper ends of air chambers are constituted so as to have their heights successively higher in their order. As the fuel and air volume are increased gradually, the flame belt is enlarged from the flame hole 5 to the flange face 9 of the large flame hole 8, and at the same time the flame shape also changes from diffusion flame to pre-mixing flame.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION This invention relates primarily to combustion stations for domestic use.

BACKGROUND OF THE INVENTION A conventional combustion apparatus of this type has a burner structure as shown in FIG. 5, for example. That is, the central flame hole 21 communicates with the mixing chamber 22, and on both sides thereof there are provided flame stabilizing air holes 23 and inclined air holes 25 arranged in a zigzag pattern on the outer inclined plate 24. These flame stabilizing air holes 23 and inclined air holes 25 communicate with an air chamber 26 below the inclined plate 24. Fuel is sent to the mixing chamber 22, and air is forcibly sent to the mixing chamber 22 and the air chamber 26 by a fan or the like, so that fuel and air are supplied proportionally.

Problems to be Solved by the Invention However, with the above configuration, the flame hole 21 is effectively supplied with air by the flame holding air hole 23 and the inclined air hole 25, resulting in high-load combustion with less flame turbulence. However, since the eight holes are fixed, even if the amount of fuel and air is controlled proportionally, as the amount of fuel is reduced and the amount of combustion is lowered, the number of flame holes 21 and flame holding air holes 23, Since the temperature of the plate material having the inclined air holes 25 decreases, the mixing chamber 2
2. The temperature of the air chamber 26 also decreases, and the temperature of the mixture and air also decreases, and the passage resistance of the 8 holes increases. Therefore, as the amount of fuel decreases, it is inevitable that the primary air ratio, which indicates the amount of air flowing into the mixing chamber, increases as shown by the dashed line A in FIG. Therefore, as shown in FIG. 4, the flame hole reaches the red-hot region, which is a general characteristic of flame, and there is a risk of deterioration of the flame hole material and backfire. Therefore, since the flame hole is used outside the red-hot region, the throttle performance can only be used up to about 30%, and the burner load adjustment range TDR (Tu
There was a problem in that it was not possible to obtain a wide rn Down Ratio.

The present invention solves such conventional problems, and aims to provide a combustion device that can be used in a wide range of applications and can perform high-load combustion and high TDR combustion with a wide aperture width.

Means for Solving the Problems In order to solve the above problems, the combustion g station of the present invention is provided with an air baffle plate having a large number of air supply holes on the lower side of the air chamber, and a flange on the air baffle plate. A fuel supply pipe with a flame hole having a surface and a hole opened at the upper end is provided, and a mixing pipe having a large flame hole larger than the flame hole and having a flange surface and a large flame hole opened at the upper end is provided outside the fuel supply pipe, An air hole is provided in the mixing tube at a position below the flame hole of the fuel supply tube, and the heights of the flame hole of the fuel supply tube, the large flame hole of the mixing tube, and the upper end of the air chamber gradually increase. It is configured as follows.

As the amount of fuel and air is gradually increased due to *li above, the flame zone expands from the flame hole to the flange surface of the flame hole, to the large flame hole, and then to the flange surface of the large flame hole. The flame zone on the hole flange surface becomes a diffusion flame, and the flame zone on the large flame hole and large flame hole flange surface becomes a premixed flame, and the flame zone and flame form change, making it possible to achieve a high TDR. Furthermore, as the flame hole for flame formation expands as the amount of fuel and air increases, the flame form becomes a premixed flame, making high-load combustion possible.

Example Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIGS. 1 and 2 are cross-sectional views illustrating the state when the TDR of a combustion apparatus according to an embodiment of the present invention is varied, and FIG. 3 is a perspective cross-sectional view of essential parts of the combustion apparatus. In FIGS. 1 to 3, reference numeral 1 denotes an air chamber, and an air rectifying plate 3 having a large number of air supply holes 2 is provided below the air chamber. A groove-shaped fuel supply pipe 4 is provided on the air baffle plate 3, the upper end of which is opened to form a flame hole 5, and furthermore, outwardly extending flange surfaces 6 are formed on both sides of the fuel supply pipe 4. ing. Also, on the outside of the fuel supply @ 4, a mixing pipe 7 is provided that extends upward along the combustion supply pipe 4, and like the fuel supply pipe 4, the upper end thereof is opened and has a hole larger than the flame hole 5. A flame hole 8 is formed, and outwardly extending flange surfaces 9 are formed on both sides thereof. The base of the mixing tube 7 is attached to the fuel supply tube 4 at an intermediate position in the vertical direction, and a plurality of air holes 10 are provided along the length of the fuel supply tube 4 below the flame hole 5 . And M material supply pipe 4J
A plate 11 surrounding the 5 and mixing tube 7 to form the air chamber 1 is provided on the outside thereof, and the large flame hole 8 of the mixing tube 7 is higher than the flame hole 5 of the fuel supply tube 4 by Ql, and the upper end of the plate 11 is is constructed to be 22 higher than the large flame hole 8 of the mixing tube 7, and the flame hole 5 of the fuel supply pipe 4, the large flame hole 8 of the mixing tube 7, and the upper end of the plate 11 are configured to be higher in sequence. The above configuration constitutes one unit, and in this embodiment, two units are arranged within the air chamber 1 with a predetermined gap. Note that the fuel supply pipe 4 and the mixing pipe 7 may have other shapes such as cylindrical, and the shapes of the air supply hole and the air hole are also free. In FIG. 2, x1 indicates the width of the flame hole 5, x2 the width of the flange surface 6, x3 the width of the large flame hole 8, and x4 the width of the seven flange 9.

In the above configuration, fuel is supplied from the fuel supply pipe 4,
Air is supplied through air supply hole 2, and fuel is supplied through flame hole 5.
Air is blown out from the gap between the air chamber 1 and the flange surface 9 and the gap between the flange surfaces 9, and is also supplied from the air hole 10. In this situation, if the amount of fuel and air is gradually increased while keeping the ratio of fuel/air amount constant using a gas proportional valve or a fan with air volume control (none of which are shown), As shown in the figure, the fuel ejected from the flame hole 5 is mixed with the upper air and the air flowing in from the air hole 10 into a diffusion flame a.
, and as the fuel increases, the same diffusion flame chamber is formed with the flange surface 6 serving as a flame holding plate. As the fuel increases further, as shown in Fig. 2, the fuel ejected from the flame hole 5 and the air flowing in from the air hole 10 are mixed at a distance of λ1, and the mixture is ejected from the large flame hole 8. Then, a premixed flame C is formed by reacting with the air ejected from the outer peripheral gap of the flange surface 9, and when combustion reaches its maximum, the flange surface 9 becomes a flame-holding plate and a premixed flame d is also formed. become. In this way, as the fuel increases, the flame hole widths xl, x2, x
3, X4, so the flame zone width also expands, and the flame hole is not the same as in the past, and as the fuel increases, the diffusion flame changes to a premixed flame, resulting in a synergistic effect of faster combustion reaction. , the flame becomes shorter, resulting in high-load combustion. In addition, when there is little fuel, diffusion combustion occurs like flames a and b, so the reaction speed is slow and the flame extends, but there is little fuel, so the combustion volume is small compared to the high-load combustion volume at maximum combustion. The reaction is completed, and above all, because it reacts with air at the fuel injection surface, there is no backfire, making it possible to achieve high TDR combustion that can reduce the fuel to zero. Therefore, in the conventional combustion characteristics, as shown in FIG. 4, when the combustion amount decreases, the primary air ratio increases as shown in the curve A of the - point steel wire, but according to this embodiment, the primary air ratio increases as shown in the curve A of the - point steel wire.
As shown in B, it changes within the stable combustion range, and the combustion amount is 20%.
Below, it becomes a diffusion flame of 1 water and air.

Therefore, it does not enter the red-hot region of the flame hole like the conventional MA, there is no backfire, and furthermore, the T
The DR is also 1/3 in the conventional method, but in this embodiment, it can be increased to infinity below 1710.

Effects of the Invention As mentioned above, the combustion apparatus of the present invention provides the following effects.

(1) Flame holes with flange surfaces are provided inside and outside and at different heights, and air is taken into the inner flame holes.
Since the flame form can be changed from a diffusion flame to a premixed flame,
This has the effect of achieving high TDR combustion.

(2) Similarly, the flame width can be expanded as the fuel increases, and the flame form can be changed from a diffusion flame with a slow reaction to a premixed flame with a fast combustion reaction, so there is an effect that high-load combustion can be performed due to a synergistic effect.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of an X5 combustion apparatus showing one embodiment of the present invention, FIG. 3 is a perspective cross-sectional view of essential parts of the same combustion apparatus, and FIG.
The figure is a combustion characteristic diagram based on combustion amount and primary air ratio, and FIG. 5 is a perspective sectional view of a conventional combustion device. 1...Air chamber, 2...Air supply hole, 3...Air straightening plate, 4...Fuel supply pipe, 5...Flame hole, 6...Flange surface, 7...Mixing Pipe, 8...Large flame hole, 9...
Flange surface, 10...Air hole, 11...Air chamber plate material. Agent Moriki Zan Hiroshi 3, etc. rectifying plate 4 combustion pF smallpox sound turret figure 2 χ4 d1. 'S Figure 3 i Figure 4 Monthly Achievement (%)

Claims (1)

[Claims] 1. An air rectifying plate with a large number of air supply holes is provided on the lower side of the air chamber, and a fuel supply pipe with a flame hole having a flange surface at the upper end is provided on the air rectifying plate. A mixing tube having a flange surface and a large flame hole larger than the flame hole opened at the upper end is provided on the outside, and an air hole is provided in the mixing tube at a position below the flame hole of the fuel supply tube, and A combustion device configured such that the heights of a flame hole of a fuel supply pipe, a large flame hole of the mixing tube, and an upper end of the air chamber gradually increase.