JPH04151411A - Low nitrogen oxides burner - Google Patents

Abstract

PURPOSE:To reduce NOX by installing in parallel ejection bodies having an ejection port in the upper part by way of a port board having a laterally-shape slit installed in a zigzag manner with the ejection hole and supplying combustion enriched mixed fuel gas to one ejection body and combustion thin mixed fuel gas to the other ejection body in a captioned device for a household burner. CONSTITUTION:Ejection bodies 1 are installed in parallel with a wide flame port board 3 having a laterally-shaped slit 4 between where they are provided with an ejection hole in the upper part and extend longitudinally. The slits 4 and the ejection holes 2 are laid out in a zigzag manner. Combustion enriched fuel gas is supplied to the ejection body or the flame port board on one side while combustion thin mixed fuel gas is supplied to the other ejection board or the flame port board, thereby carrying out thick and thin combustion. In this construction, enriched mixed fuel gas on one side carries out excess air combustion and inhibits NOX by the cooling action of the excess air and uses the flames of the other enriched mixed fuel gas as its fire source, and attains stabilized combustion. It is, therefore, possible to inhibit the lift and vibration of flames and prevent the generation of NOX.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a burner that generates low nitrogen oxides for use in small-sized combustion devices for household use, small-sized commercial use, and the like.

(Prior art) Nitrogen oxides (NOx) in the combustion gas of burners in various combustion devices are not only toxic in themselves, but are also considered to be one of the causes of acid rain and photochemical smog. Various measures have been developed and taken for burners used in the apparatus to reduce the amount of NOx generated.

(Problem to be solved by the invention) However, conventionally, these measures have mainly been taken for large-scale combustion equipment for industrial use, etc., which are subject to legal restrictions.
Small-sized combustion devices for home use and small-scale commercial use have problems such as noise, so it cannot be said that sufficient countermeasures are necessarily taken.

In other words, in large combustion equipment, the static pressure of the combustion fan can be increased, making it easy to control the flow of combustion gas and air.Secondly, there is a high degree of freedom in burner layout, and noise countermeasures are also easy. Due to these advantages, the conditions for countermeasures against noise are not strict, and the combustion chamber can be made large, so it has the advantage that it is easy to achieve complete combustion even if measures are taken to reduce NOx by slow combustion. for,
Small combustion devices do not have these advantages, and therefore it is difficult to take reduction measures in small combustion devices compared to large combustion devices.

The present invention aims to solve the above-mentioned conventional problems by rationally applying so-called concentration combustion to a small-sized σ) furnace firing apparatus.

(Means for Solving the Problems) Means for solving the above-mentioned problems will be explained with reference to drawings corresponding to embodiments.The first configuration of the low nitrogen oxide generation burner of the present invention is The ejection bodies 1 extending in the horizontal direction and having the ejection holes 2 formed in the upper part are arranged side by side at intervals on the left and right sides, and there is a wide flame hole extending in the length direction between the inner two parts of the ejection bodies 1. A plate 3 is provided, and a large number of slit flame holes 4 in the width direction are formed in the longitudinal direction at intervals, and the ejection holes 2 and the slit flame holes 4 are arranged in a staggered manner with respect to each other. 6, the jet body 1 is provided with a side flame forming plate 5 on the outside and a side fire nozzle 6, and a fuel-rich mixture is supplied to either one side of the jet body 1 or the flame hole plate 3. At the same time, the structure is such that a fuel-lean mixture is supplied to the assembly side to perform rich and lean combustion.

Next, in the second configuration, jet bodies 1 extending in the length direction and having jet holes 2 formed in their upper parts are arranged side by side at intervals on the left and right sides, and a wide space is provided between the upper inner sides of the jet bodies 1. A flame hole plate 3 extending in the length direction is provided, and a large number of slit flame holes 4 in the width direction are formed in the flame hole plate 3 at intervals in the length direction.
The Surirami flame hole 4 is formed to be biased toward the center side away from the ejector body 1, and the front ejector body 1 is provided with a side flame forming plate 5 on the outside and a side flame ejection hole 6, A fuel-rich mixture is supplied to either one side of the multilayer ejector l or the flame hole plate 3, and a lean combustion is performed by supplying a fuel-lean mixture to the other side j5. It is.

Next, the third configuration extends to a length -jj 1t.; and has a jet hole 2 formed in a part of the jet IA, i. 'Listed side by side with a gap on the right side, 1 and 1' of the gauge ejector l, i II
In the living room, there is a flame hole plate 3 that is wide and extends in the direction f' Formed in large numbers and squirted into Moe.
The slit flame holes 4 are arranged in a 1,000-1 pattern with each other, and the slit flame holes 4 are arranged in the form of Rti, .
(Form one body with a bias towards the center, 11
jεl ejection body) is provided with a side flame forming plate 5 on the outside and a side flame ejection hole 6, and a fuel-rich mixture is supplied to either one side of the ejection body 1 or the flame hole plate 3,
The structure is such that a fuel-lean mixture is supplied to the other side to perform rich and lean combustion.

In the above configuration, the flame hole plate 3 is provided so that a gap 7 is formed between its side wall and the side wall of the ejector 1, and the ejector 1 is provided with a side flame ejector corresponding to this gap 7. A hole 6 can be formed.

The burner described above can be configured as a unit, and the units can be arranged in a row to configure a desired burner.

(Function) In the above configuration, first, a fuel-rich mixture is supplied to the ejection bodies 1, and a fuel-lean mixture is supplied to the flame hole plate 3 through the space 8 between the ejection bodies 1. Allow combustion to occur.

The fuel-rich air-fuel mixture is ejected from the ejection bodies 1 located on both sides of the flame hole plate 3 and burns in a combustion region with a low oxygen partial pressure, thereby suppressing the generation of NOx.

On the other hand, the fuel-lean mixture is injected above the flame hole plate 3 and combusted, and since this combustion is the combustion of excess air, the temperature of the flame is maintained at a low temperature due to the cooling effect of this excess air. This suppresses the generation of NOx. The combustion of this excess air is
When used alone, the flame stability is poor, but since the flame of the above-mentioned ejector 1 acts as a pilot flame, the flame stability is good even when excess air is combusted. Therefore, there is no flame lift or vibration combustion, and noise generation due to this is suppressed. Additionally, this excess air acts to supply secondary air to the flame above the ejection body 1, thus preventing the occurrence of incomplete combustion in the combustion of the fuel-rich mixture described above. can.

Next, while supplying a lean fuel mixture to the ejector 1,
A rich mixture of fuel is supplied to the flame hole plate 3 to cause combustion.

In this case, the fuel-lean air-fuel mixture is ejected from the side flame nozzle 6, and the flame is maintained by the side flame formed above the side flame forming plate 5, and the mixture is stabilized above the jet body 1. The excess air is combusted, while the fuel-rich mixture is burned through the flame hole plate 3.
The fuel is ejected upward and combusts with a low oxygen partial pressure. At this time, the excess air supplied from the flame of the ejector 1 is used as secondary air to achieve complete combustion. Therefore, in this case as well, NOx can be suppressed by concentration combustion and combustion stability can be achieved.

In this way, by supplying a fuel-rich mixture to either the right side of the ejector or flame hole plate 3, and supplying a fuel-lean mixture to the other side to perform rich/lean combustion, low noise and low noise can be achieved. It is possible to realize the combustion of NOx, and
The reduction in efficiency due to combustion of excess air can be compensated for.

In the above combustion operation, in the first configuration described above, the injection holes 2 and the slit flame holes 4 are arranged in a staggered manner, so that a fuel-rich mixture and a fuel-lean mixture are ejected from each. It is possible to prevent partial direct collision with air, and this collision can prevent the generation of a high temperature region where partial [; It is possible to prevent unstable combustion due to the occurrence of watersheds.

In addition to arranging the nozzle holes 2 and the slit flame holes 4 in a staggered manner, the partial direct collision of the air-fuel mixture as in the second configuration can be achieved by arranging the nozzle holes 2 and the slit flame holes 4 in a staggered manner. This can also be prevented by forming it biased towards the center, away from 1.

Further, as in the third configuration, these can be used in combination to more reliably prevent the problem.

In the above burner, as in the fourth configuration, the flame hole plate 3 is provided so that a gap 7 is formed between its side wall and the side wall of the ejector 1, and If the ejecting body 1 is provided with the side flame ejection holes 6, when performing combustion with a lean mixture of fuel, side flames will be formed on both sides of the ejecting body 1, so that such combustion can be performed more stably. I can do it.

The above-mentioned burner is constructed as a unit, and by arranging the units in series, a burner with a desired combustion amount can be constructed.

In such a configuration, when a lean mixture of fuel is supplied to the ejection body l for combustion, the temperature of the flame corresponding to both ends of the burner as a whole is low, so the combustion chamber is designed to be narrow. Therefore, it is advantageous from the viewpoint of preventing overheating if the water-cooled walls of the heat exchanger are close to both ends of the burner.

(Example) Next, embodiments of the present invention will be described with reference to the drawings.

First, in all the figures, reference numeral 1 indicates a jetting body 1, which extends in the length direction and has a jetting hole 2 formed in its upper part. The ejecting bodies 1 are arranged side by side at intervals on the left and right sides, and a wide flame hole plate 3 extending in the length direction is provided between the upper inner sides of the ejecting bodies 1. A large number of slit flame holes 4 are formed at intervals in the length direction. The ejector body 1 is provided with a side flame forming plate 5 on the outside and a side flame ejection hole 6.

In the embodiment shown in FIG. 1, the nozzle holes 2 and the slit flame holes 4 are arranged in a staggered manner, and the nozzle holes 2 are arranged in pairs, as shown in FIG. 1(b). It has a parallel configuration.

Further, in the embodiment shown in FIG. 2, the slit flame hole 4 is formed so as to be biased towards the center, away from the ejection body 1.

Even in the configuration of this embodiment), the jet holes 2 and the slit flame holes 4 can be arranged in a staggered manner with respect to each other, as in the embodiment of FIG.

In the embodiment shown in FIG. 3, the flame hole plate 3 is provided so that a gap 7 is formed between its side wall and the side wall of the ejector 1, and the ejector l In the above configuration in which the flame ejection holes 6 can be formed in the flame ejector 1, the air-fuel mixture is supplied to the ejection body 1 through an appropriate mixing section, and the flame hole plate 3 is also provided with an appropriate flame hole plate 3. The configuration is such that the air-fuel mixture is supplied from the mixing section through the gap section 8 between the ejection bodies 1. Although not shown in the drawings, such a mixing section may have an appropriate structure, such as, for example, similar to a conventional Bunsen burner, fuel gas is ejected into the throat section of the mixing section and surrounding air is sucked and mixed.

By adjusting the mixing section in this way, it is possible to supply a fuel-rich mixture to either one side of the ejection body 1 or the flame hole plate 3, and to supply a fuel-lean mixture to the other side. . The air ratio of the mixture supplied to each is the theoretical air amount λ
= 1, for example, in a fuel-rich mixture, λ is approximately 0.
4. In a fuel-lean mixture, λ can be approximately 1.2 to 1.5.

Moreover, the above-mentioned burner is configured as a unit, and by arranging the units in series, a burner with a desired combustion amount can be configured. In this case, although not shown in the drawings, combustion air may be supplied to the outside of the ejector l of each unit from a combustion fan via a suitable air baffle plate.

(Effects of the Invention) As described above, the present invention rationally configures the left and right ejection bodies and the flame hole plate between them to perform so-called rich and lean combustion, so that a rich mixture of fuel is produced. NO due to combustion of
By rationally coexisting the effect of reducing the amount of NOx generated and the effect of reducing the amount of NOx generated by combustion of a fuel-lean mixture, the stability of the flame in the latter combustion is improved and the generation of noise is reduced. In addition, it is possible to prevent the occurrence of incomplete combustion during the former combustion, and in this way, in small combustion equipment where measures against noise are strict, measures can be taken to reduce NOx without increasing noise. It also has the effect of not reducing efficiency.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b') show a first embodiment of the present invention, where (a) is an explanatory longitudinal sectional view and (b) is an explanatory plan view. Further, FIGS. 2 and 3 are explanatory longitudinal sectional views showing other embodiments of the present invention, respectively. Code 1: ejection body, 2: ejection hole, 3: flame hole plate, 4: slit flame hole, 5: side flame-shaped I plate, 6: ejection hole for side flame, 7: gap, 8: interval part.

Claims (5)

[Claims] (1) Ejecting bodies that extend in the length direction and have ejection holes formed in their upper parts are arranged side by side at intervals on the left and right sides, and a wide flame hole plate that extends in the lengthwise direction is provided between the upper inner sides of the ejecting bodies. A large number of slit flame holes in the width direction are formed in the flame hole plate at intervals in the length direction, and the ejection holes and the slit flame holes are arranged in a staggered manner with respect to the ejection body. A side flame forming plate is provided on the outside, and a side flame ejection hole is provided, and a fuel-rich mixture is supplied to either one side of the ejector or the flame hole plate, and a fuel-lean mixture is supplied to the other side. A low nitrogen oxide generation burner characterized by supplying concentrated and concentrated combustion. (2) Ejection bodies that extend in the length direction and have ejection holes formed in their upper parts are arranged side by side at intervals on the left and right sides, and a wide flame hole plate that extends in the length direction is provided between the upper inner sides of the ejection bodies. a plurality of slit flame holes in the width direction are formed in the flame hole plate at intervals in the length direction, and the slit flame holes are formed to be biased to the center side away from the ejecting body, The ejector body is provided with a side flame forming plate on the outside and a side flame ejection hole, and a fuel-rich mixture is supplied to either one side of the ejector body or the flame hole plate, and a fuel-rich mixture is supplied to the other side. A burner with low nitrogen oxide generation, which is characterized by supplying a mixture with a low nitrogen oxide content and performing concentrated combustion. (3) Ejectors extending in the length direction and having ejection holes formed in their upper parts are arranged side by side at intervals on the left and right sides, and a wide flame hole plate extending in the length direction is installed between the upper inner sides of the ejectors. In addition, a large number of slit flame holes in the width direction are formed in the flame hole plate at intervals in the length direction, and the jet holes and the slit flame holes are arranged in a staggered manner, and the slit flame holes are arranged in a staggered manner. is formed so as to be biased towards the center, away from the ejection body, and the ejection body is provided with a side flame forming plate on the outside and a side flame ejection hole, and either one of the ejection body or the flame hole plate is provided. A low nitrogen oxide generation burner characterized by supplying a fuel-rich mixture to one side and supplying a fuel-lean mixture to the other side to perform rich/lean combustion. (4) The flame hole plate according to claim 1 or 2 is provided so that a gap is formed between its side wall and the side wall of the ejector, and the ejector has a side flame ejection hole corresponding to this gap. A burner with low nitrogen oxide generation characterized by (5) A low nitrogen oxide generation burner, characterized in that the burner according to claim 1, 2, 3 or 4 is configured as a unit, and the units are arranged in series.