JP2003083535A - Combustion equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a combustion chamber small by supplying secondary air to the vicinity of a primary flame and shortening a secondary flame, and to suppress the occurrence of NOx, and besides to prevent the deformation or damage of the periphery of a burner head or the occurrence of reverse fire. SOLUTION: In combustion equipment which is equipped with a fuel supply pipe 13 for supplying fuel to an evaporating chamber 1 for evaporating liquid fuel, an air nozzle 8 for supplying primary air to the evaporating chamber 1, a burner head 4 having a flame hole 5 for jetting out mixed gas where evaporated fuel and primary air are mixed thereby forming a primary flame 6, an ignition plug 14 for igniting the mixed gas jetted out of the flame hole 5, a flame holding plate 15 around the primary flame 6, and a secondary air blowout port 12 which blows out the secondary air 10 circulated from the secondary air circulation port 9 to the vicinity of the primary flame 6, the whole of the secondary air blowout port 12 is positioned in a position under the top end of the flame holding plate 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device, and more particularly, to a combustion device used in a domestic heater for premixing combustion air and fuel for combustion.

[0002]

2. Description of the Related Art A typical example of a combustion device that vaporizes and combusts liquid fuel is disclosed in Japanese Patent Laid-Open No. 3-156204. In this publication, a burner head for forming a primary flame is provided above the vaporization chamber for vaporizing liquid fuel such as kerosene, and a blower pipe and a fuel supply pipe are provided on the side wall of the vaporization chamber. Combustion air is supplied to the vaporization chamber from a blower via a blower pipe, liquid fuel is supplied from a fuel pump via a fuel pipe, and the liquid fuel is vaporized on a vaporization surface preheated to a temperature required for vaporization,
A mixture with combustion air is produced.

The amount of combustion air in the air-fuel mixture in this combustion device is about 0.8 times the amount of air at which kerosene theoretically completely burns (= theoretical air amount), that is, the air ratio corresponds to 0.8. Quantity supplied. This air-fuel mixture is ignited by the igniter on the flame holes of the burner head to form a primary flame. The remaining secondary air required for complete combustion is supplied from the convection fan, the primary combustion gas in the downstream of the primary flame is completely combusted, and this combustion gas is used for indoor heating.

In this type of combustion device, a large secondary flame is formed because secondary air is supplied to the primary combustion gas downstream of the primary flame, and a relatively large combustion chamber is required. Therefore, the combustion device is large. There is a problem of becoming.

In order to solve this problem, secondary air required for complete combustion is forcibly supplied in the vicinity of the primary flame to promote combustion, thereby shortening the secondary flame and making the combustion chamber smaller. An example of such a combustion device is Shokai 56-173819
It is shown in the publication. FIG. 22 is a partial cross-sectional view showing the combustion device shown in the publication. In the figure, 21 is a main body, 22 is a vaporizing and mixing chamber, 23 is a combustion chamber, 24 is a nozzle, 25 is an air passage for primary combustion, 26 is a blower, 27 is a constant oil level, 28 is a pressure pipe, 29 Is an air flow path for secondary air,
30 is a liquid fuel supply path, 31 is a secondary air guide plate, 32 is a flame hole, 33 is a valve, the valve 33 is opened, and the liquid fuel supplied from the nozzle 24 is the primary air supplied from the blower 26. Is mixed in the vaporization / mixing chamber 22, and the mixed air-fuel mixture is ignited in a flame hole 32 above the vaporization / mixing chamber 22 to form a primary flame. In addition, the secondary air is guided in the direction of the primary flame by the secondary air guide plate 31 through the secondary air passage 29, and is supplied to the vicinity of the primary flame to form a relatively short secondary flame. To be done.

[0006] However, in this type of combustion device, the combustion reaction is rapidly advanced by promoting combustion,
There is a problem that the secondary flame temperature rises and nitrogen oxides (hereinafter, referred to as NOx) are easily generated.

Further, there is a problem that not only deformation and damage around the burner head occur due to the temperature rise, but also flashback is likely to occur.

[0008]

As described above, although the combustion chamber can be made small in the conventional combustion apparatus, NOx is likely to be generated, and not only the burner head periphery is deformed or damaged due to the temperature rise, but also However, there is a problem that it is easy to cause a flashback.

The present invention has been made to solve the above problems, and suppresses the generation of NOx, prevents the deformation and damage around the burner head, or prevents the occurrence of flashback, and at the same time, the combustion device Aim for compactness.

[0010]

In a combustion apparatus according to a first aspect of the present invention, vaporizing means for vaporizing liquid fuel, liquid fuel supplying means for supplying liquid fuel to the vaporizing means, and primary air for the vaporizing means. Is communicated with the first air supply means for supplying the air, and a mixture of the fuel vaporized by the vaporization means and the primary air is ejected to form a primary flame. An elongated strip-shaped burner head having a flame hole, an ignition means for igniting an air-fuel mixture ejected from the flame hole, a flame holding member provided around the primary flame, and a primary flame supplied to the primary flame. A secondary air flow passage through which secondary air forming a secondary flame flows; and a secondary air outlet for blowing the secondary air supplied from the secondary air flow passage to the vicinity of the primary flame. All of the secondary air outlets are below the upper end of the flame holding member. It is characterized in that in the position.

In the combustion apparatus according to the second aspect of the present invention, the vaporizing means for vaporizing the liquid fuel, the liquid fuel supplying means for supplying the liquid fuel to the vaporizing means, and the first air for supplying the primary air to the vaporizing means are provided. Communicating with an air supply means and the vaporization means,
A slender strip-shaped burner head having a flame hole for ejecting a mixture of the fuel vaporized by the vaporizing means and the primary air to form a primary flame, and the jet from the flame hole Igniting means for igniting the air-fuel mixture, a flame holding member provided around the primary flame, and a secondary air flow passage through which secondary air supplied to the primary flame to form a secondary flame flows. A secondary air outlet for blowing the secondary air supplied from the secondary air flow passage to the vicinity of the primary flame,
All or part of the secondary air outlet is located above the upper end of the flame holding member.

In the combustion apparatus according to the third aspect of the present invention, the vaporizing means for vaporizing the liquid fuel, the liquid fuel supplying means for supplying the liquid fuel to the vaporizing means, and the first air for supplying the primary air to the vaporizing means are provided. Communicating with an air supply means and the vaporization means,
A slender strip-shaped burner head having a flame hole for ejecting a mixture of the fuel vaporized by the vaporizing means and the primary air to form a primary flame, and the jet from the flame hole Igniting means for igniting the air-fuel mixture, a flame holding member provided on one side surface of the primary flame, and a secondary air flow passage through which secondary air supplied to the primary flame to form a secondary flame flows. And a secondary air outlet that blows out secondary air supplied from the secondary air flow passage in the vicinity of the primary flame from a position facing the flame holding member, and all of the secondary air outlets are provided. It is characterized in that it is located below the upper end of the flame holding member.

In the combustion apparatus according to the fourth aspect of the invention, the vaporizing means for vaporizing the liquid fuel, the liquid fuel supplying means for supplying the liquid fuel to the vaporizing means, and the first air for supplying the primary air to the vaporizing means are provided. Communicating with an air supply means and the vaporization means,
A slender strip-shaped burner head having a flame hole for ejecting a mixture of the fuel vaporized by the vaporizing means and the primary air to form a primary flame, and the jet from the flame hole Igniting means for igniting the air-fuel mixture, a flame holding member provided on one side surface of the primary flame, and a secondary air flow passage through which secondary air supplied to the primary flame to form a secondary flame flows. And the secondary air supplied from the secondary air flow passage is blown out in the vicinity of the primary flame from a position facing the flame holding member, and all or part of the secondary air is at a position above the upper end of the flame holding member. A secondary air outlet is provided.

A combustion apparatus according to a fifth aspect of the invention is characterized in that, in the first to fourth aspects, a heat recovery member is provided between the flame holes on the burner head having a plurality of flame holes. It is a thing.

A combustion apparatus according to a sixth aspect of the present invention is the combustion apparatus according to any one of the first to fifth aspects, wherein a catalyst for oxidizing the air-fuel mixture is provided inside the burner head.

According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the catalyst placed inside the burner head is placed in contact with the burner head.

In a combustion apparatus according to an eighth aspect of the present invention, in the sixth aspect of the present invention, a portion of the catalyst installed inside the burner head is provided in a flame hole portion communicating with the inside of the burner head. .

In the combustion apparatus according to the ninth invention, in the fifth invention, the heat recovery member is connected to the inside of the burner head, and the heat recovery member inside the burner head is equipped with a catalyst for oxidizing the air-fuel mixture. It is a thing.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Embodiment 1 according to the present invention will be described with reference to FIGS. 1 and 2. Figure 1
FIG. 3 is a sectional view showing a structure of a combustion apparatus according to Embodiment 1 of the present invention. FIG. 2 is a sectional view taken along the line II-II. 1 and 2, the same reference numerals in each figure indicate the same or corresponding portions.

In the figure, 1 is a vaporization chamber which is a chamber for vaporizing kerosene fuel, 2 is an electric heater which is embedded in a side wall of the vaporization chamber 1, and which heats the vaporization chamber 1, 3 is an upper portion of the vaporization chamber 1. 4 is a slender strip-shaped burner head provided on the upper part of the throttle unit 3, and 5 is 1
A flame hole in which the secondary flame 6 is formed, 7 is a flow dividing chamber, 8 is an air nozzle, 9 is a secondary air passage, 10 is secondary air, 12 is a secondary air outlet, 13 is a fuel supply pipe, and 14 is Ignition plug, 15
Is a flame holding plate surrounding the burner head 4, 16 is a secondary flame, and 17 is a combustion cylinder.

In the first embodiment, the secondary air 10 for complete combustion is forcibly supplied to the vicinity of the primary flame 6 by the secondary air outlet 12. Further, all of the secondary air outlets 12 are located below the upper end of the flame holding plate 15.

The vaporization chamber 1, the electric heater 2 and the throttle unit 3 constitute a premix chamber for premixing air and fuel to generate a mixture. Further, the air nozzle 8 is connected to a combustion blower (not shown), and the air supplied from the combustion blower is the primary air supplied to the vaporization chamber 1 in the flow dividing chamber 7 and the secondary air circulation port 9 It is branched to the secondary air to be supplied to. Further, the secondary air outlet 12 is arranged at a position below the upper end of the flame holding plate 15. The fuel supply pipe 13 is arranged coaxially with the air nozzle 8 and is arranged so that its tip portion protrudes into the vaporization chamber 1, and kerosene in a kerosene tank (not shown) passes through the fuel supply pipe 13 to kerosene. Pump (not shown)
Is supplied to the vaporization chamber 1.

Next, the operation will be described. By energizing the electric heater 2, the vaporization chamber 1 is preheated to a temperature (250 to 300 ° C.) necessary for vaporizing kerosene fuel. After the completion of preheating, the combustion air sent from the blower for combustion is supplied from the air nozzle 8 to the vaporization chamber 1 as primary air. Further, a predetermined amount of kerosene fuel is constantly supplied to the vaporization chamber 1 from the fuel supply pipe 13. The supply amount of primary air is about 0.8 times the air amount (= theoretical air amount) at which kerosene theoretically completely burns, that is, the air ratio corresponds to 0.8. The remaining air required for complete combustion is supplied by the secondary air 10, and the amount of air is usually an amount corresponding to an air ratio of 0.4 to 0.8.

The supplied kerosene fuel is atomized by the flow of primary air and vaporized on the preheated vaporization surface. The vaporized kerosene fuel is further premixed with the primary air when passing through the throttle portion 3 to become a mixture having a uniform concentration distribution. The air-fuel mixture thus generated flows out from the flame hole 5 of the burner head 4 and is ignited by the sparks discharged from the ignition plug 14 to the outer peripheral portion of the flame hole 5 to form the primary flame 6. 1
Secondary air 10 is supplied to secondary flame 6 through secondary air outlet 12 to form secondary flame 16. This secondary flame 16
Complete combustion is performed in the internal space of the combustion cylinder 17 while ensuring the stability of combustion by the flame holding plate 15. The burned gas is mixed with air from a convection fan (not shown) and used for heating the room. After the combustion is started, the vaporization chamber 1 is heated by the heat recovery from the flame, so that the electric heater 2 does not need to be energized.

The secondary air 10 for complete combustion is 2
Since the secondary air outlet 12 is forcibly supplied to the vicinity of the primary flame 6, the combustion reaction is promoted. Therefore, the secondary flame 16 becomes shorter and the combustion space required for combustion becomes smaller, so that the combustion cylinder 17 becomes smaller and the combustion apparatus can be made compact.

Further, since the burner head has an elongated strip shape, the size of the burner in the depth direction becomes small, and the combustion apparatus can be made compact.

Since all of the secondary air outlets 12 are installed below the upper end of the flame holding plate 15, the secondary air 10
The secondary flame 16 that has become hot due to the promotion of the combustion reaction comes into contact with the flame holding plate 15, and the secondary flame 16 causes the flame holding plate 1 to move.
The heat of the flame is transmitted to 5, and the heat transmitted to the flame holding plate 15 is dissipated to the surroundings as radiant heat, so that the secondary flame 16 is cooled.
As a result, it is possible to suppress the generation of NOx generated in the secondary flame 16.

Further, since the temperature of the secondary flame 16 is lowered, it is possible to prevent the deformation and damage around the burner head and the occurrence of flashback.

The shape of the flame holding plate 15 constituting the flame holding member is not limited to the plate shape, and various shapes such as a flame holding plate 15 with its upper end portion wider than its lower end portion can be used.

According to the first embodiment of the present invention, the liquid fuel including the vaporization means including the vaporization chamber 1 for vaporizing the liquid fuel and the fuel supply pipe 13 for supplying the liquid fuel to the vaporization means including the vaporization chamber 1 A first air supply unit including a supply unit, an air nozzle 8 for supplying primary air to the vaporization unit including the vaporization chamber 1, and a vaporization unit including the vaporization chamber 1 and communicating with the vaporization chamber 1. The combustion apparatus is provided in a horizontal state with a plurality of flame holes 5 arranged on the same line in which the primary flame 6 is formed by ejecting an air-fuel mixture formed by mixing the fuel vaporized by the vaporization means and the primary air. A long and narrow strip-shaped burner head 4 extending left and right when viewed from the front, an ignition means including an ignition plug 14 for igniting a mixture gas ejected from the flame holes 5, and a flame holding device provided around the primary flame 6. Consisting of plate 15 A secondary air flow passage including a flame member, a secondary air flow port 9 through which secondary air that supplies the primary flame 6 and forms a secondary flame 16 flows, and the secondary air flow port 9 Secondary air 1 supplied from the secondary air flow passage
Secondary air outlet 12 that blows out 0 near the primary flame 6
And the secondary air outlet 12 is entirely located at a position below the upper end of the flame holding member formed of the flame holding plate 15, the following effects can be obtained. Since the secondary air 10 is forcibly supplied to the primary air, the secondary flame 1
6 can be shortened and the combustion device can be made compact. Further, since all of the secondary air outlets 12 are located below the upper end of the flame holding member made of the flame holding plate 15, the secondary flame 16 is cooled by the flame holding member made of the flame holding plate 15 and NOx.
It is possible to suppress the generation of heat and to prevent deformation and damage around the burner head 4 or the occurrence of flashback.
Further, since the burner head 4 has an elongated strip shape, the size of the burner in the depth direction becomes small, and the combustion device can be made compact.

Embodiment 2. A second embodiment according to the present invention will be described with reference to FIGS. FIG. 3 is a sectional view showing the structure of a combustion apparatus according to Embodiment 2 of the present invention. FIG. 4 is a characteristic diagram showing test results in the first and second embodiments according to the present invention.
In the second embodiment, the configuration other than the peculiar configuration described here has the same configuration as the configuration in the first embodiment described above, and exhibits the same operation. In the drawings, the same reference numerals indicate the same or corresponding parts.

In the second embodiment, the secondary air outlet 1
All or part of 2 is installed at a position above the upper end of the flame holding plate 15. Even in such a case, there is an effect that the primary flame 6 comes into contact with the flame stabilizing plate 15, so that the primary flame 6 is cooled and the generation of NOx can be suppressed.

FIG. 4 is a characteristic diagram showing the test results of the amount of NOx produced and the maximum temperature of the flame holding plate 15 in the first and second embodiments, together with the characteristics when the flame holding plate 15 is not provided for comparison. ing.

When the heating output (combustion amount) is 4 kW and the flame holding plate 15 is not provided, the NOx emission concentration is about 130 pp.
It is about m. In the case of the second embodiment according to the present invention, the temperature of the flame holding plate 15 rises to about 765 ° C.
It can be seen that the next flame 6 is cooled. N at this time
The Ox emission concentration is reduced to about 110 ppm. In the case of the first embodiment according to the present invention, the temperature of the flame holding plate is about 815 ° C.
And the secondary flame 16 has been cooled, and NO
The x emission concentration is also reduced to about 93 ppm.

According to the second embodiment of the present invention, the liquid fuel including the vaporization means including the vaporization chamber 1 for vaporizing the liquid fuel and the fuel supply pipe 13 for supplying the liquid fuel to the vaporization means including the vaporization chamber 1 A first air supply unit including a supply unit, an air nozzle 8 for supplying primary air to the vaporization unit including the vaporization chamber 1, and a vaporization unit including the vaporization chamber 1 and communicating with the vaporization chamber 1. The combustion apparatus is provided in a horizontal state with a plurality of flame holes 5 arranged on the same line in which the primary flame 6 is formed by ejecting an air-fuel mixture formed by mixing the fuel vaporized by the vaporization means and the primary air. A long and narrow strip-shaped burner head 4 extending left and right when viewed from the front, an ignition means including an ignition plug 14 for igniting a mixture gas ejected from the flame holes 5, and a flame holding device provided around the primary flame 6. Consisting of plate 15 From the secondary air flow passage 9 including a flame member and a secondary air flow passage 9 through which the secondary air 10 that supplies the primary flame 6 and forms the secondary flame 16 flows Secondary air outlet 12 that blows out the secondary air 10 supplied from the secondary air flow passage to the vicinity of the primary flame 6, and all or part of the secondary air outlet 12 is the flame holding plate. Since the flame holding member made of 15 is located at a position above the upper end of the flame holding member, the following effects can be obtained. Since the secondary air 10 is forcibly supplied to the primary air, the secondary flame 16 is shortened and the combustion device can be made compact. Further, since all of the secondary air outlets 12 are located above the upper end of the flame holding member made of the flame holding plate 15, the primary flame 6 is cooled by the flame holding member made of the flame holding plate 15, and N
Generation of Ox can be suppressed, and deformation or damage around the burner head 4 or occurrence of flashback can be prevented. Further, since the burner head 4 has an elongated strip shape, the size of the burner in the depth direction becomes small, and the combustion device can be made compact.

Embodiment 3. A third embodiment according to the present invention will be described with reference to FIGS. FIG. 5 is a sectional view showing the structure of the combustion apparatus according to the third embodiment of the present invention. FIG. 6 is a sectional view taken along the line VI-VI. In the third embodiment, the configuration other than the specific configuration described here is the same as that of the first embodiment described above.
It has the same configuration as that of the above-mentioned and has the same operation. In the drawings, the same reference numerals indicate the same or corresponding parts.

In the third embodiment, the flame holding plate 15 is provided on one side of the primary flame, and all of the secondary air outlets 12 are located below the upper end of the flame holding plate 15 at opposite positions of the flame holding plate 15. It is installed in the position.

Since the secondary flame 16 is pressed against the flame holding plate 15 by the flow of the secondary air 10 supplied from the secondary air outlet 12, the heat of the flame is transmitted from the secondary flame 16 to the flame holding plate 15. The heat transmitted to the flame holding plate 15 is easily dissipated to the surroundings as radiant heat, and the secondary flame 16 is cooled. As a result, it is possible to suppress the generation of NOx generated in the secondary flame 16.

Further, since the temperature of the secondary flame 16 is lowered, it is possible to prevent deformation and damage around the burner head and occurrence of flashback.

According to the third embodiment of the present invention, the liquid fuel including the vaporization means including the vaporization chamber 1 for vaporizing the liquid fuel and the fuel supply pipe 13 for supplying the liquid fuel to the vaporization means including the vaporization chamber 1 A first air supply unit including a supply unit, an air nozzle 8 for supplying primary air to the vaporization unit including the vaporization chamber 1, and a vaporization unit including the vaporization chamber 1 and communicating with the vaporization chamber 1. The combustion apparatus is provided in a horizontal state with a plurality of flame holes 5 arranged on the same line in which the primary flame 6 is formed by ejecting an air-fuel mixture formed by mixing the fuel vaporized by the vaporization means and the primary air. A long and narrow strip-shaped burner head 4 extending left and right when viewed from the front, an ignition means including an ignition plug 14 for igniting a mixture gas ejected from the flame holes 5, and a flame holding device provided on one side of the primary flame. Consisting of plate 15 A secondary air flow passage including a flame member, a secondary air flow port 9 through which secondary air that supplies the primary flame 6 and forms a secondary flame 16 flows, and the secondary air flow port 9 Secondary air 1 supplied from the secondary air flow passage
And a secondary air outlet 12 that blows 0 in the vicinity of the primary flame 6 from a position facing the flame holding plate 15, and the secondary air outlet 12 is entirely made of the flame holding plate 15. Since it is located below the upper end of the, the following effects can be achieved. The secondary flame 16 is pressed against the flame holding member composed of the flame holding plate 15 by the flow of the secondary air 10 supplied from the secondary air outlet 12 for forcibly supplying the secondary air 10 to the primary air. Therefore, the heat of the flame is easily transferred from the secondary flame 16 to the flame holding plate 15 as a flame holding member, and the heat transmitted to the flame holding member formed of the flame holding plate 15 is dissipated to the surroundings as radiant heat and the secondary flame is discharged. 16 is cooled. As a result, it is possible to suppress the generation of NOx generated in the secondary flame 16. Further, since the temperature of the secondary flame 16 is lowered, it is possible to prevent deformation and damage around the burner head 4 or occurrence of flashback.

Fourth Embodiment A fourth embodiment according to the present invention will be described with reference to FIGS. 7 and 8. FIG. 7 is a sectional view showing the structure of a combustion apparatus according to Embodiment 4 of the present invention. FIG. 8 is a characteristic diagram showing test results in the third embodiment and the fourth embodiment according to the present invention.
In the fourth embodiment, the configuration other than the specific configuration described here has the same configuration as the configurations in the first and third embodiments described above, and exhibits the same operation. . In the drawings, the same reference numerals indicate the same or corresponding parts.

In the fourth embodiment, the flame holding plate 15 is provided on one side of the primary flame, and all or part of the secondary air outlet 12 is provided at the upper end of the flame holding plate 15 at a position facing the flame holding plate 15. It is installed at the above position. Even in such a case, there is an effect that the primary flame 6 comes into contact with the flame stabilizing plate 15, so that the primary flame 6 is cooled and the generation of NOx can be suppressed.

According to the test results of the present inventors, NOx in the case of using the combustion device of the third and fourth embodiments described above.
An example of the relationship between the discharge characteristic and the maximum temperature of the flame holding plate 15 is as shown in FIG. For comparison, FIG. 8 shows characteristics together with the case where the flame holding plate 15 is not provided.

When the heating output (combustion amount) is 4 kW, the NOx emission concentration is about 130 pp without the flame holding plate 15.
It is about m. In the case of the fourth embodiment according to the present invention, the temperature of the flame holding plate 15 rises to about 740 ° C.
It can be seen that the next flame 6 is cooled. N at this time
Ox emission concentration is reduced to about 115 ppm. In the case of the third embodiment according to the present invention, the temperature of the flame holding plate 15 is about 82.
Since the temperature rises to 5 ° C. and the secondary flame 16 is pressed against the flame holding plate 15, the heat of the flame is easily transferred from the secondary flame 16 to the flame holding plate 15, and the secondary flame 16 is further cooled. The NOx emission concentration is also reduced to about 86 ppm.

According to the fourth embodiment of the present invention, the liquid fuel including the vaporization means including the vaporization chamber 1 for vaporizing the liquid fuel and the fuel supply pipe 13 for supplying the liquid fuel to the vaporization means including the vaporization chamber 1 A first air supply unit including a supply unit, an air nozzle 8 for supplying primary air to the vaporization unit including the vaporization chamber 1, and a vaporization unit including the vaporization chamber 1 and communicating with the vaporization chamber 1. The combustion apparatus is provided in a horizontal state with a plurality of flame holes 5 arranged on the same line in which the primary flame 6 is formed by ejecting an air-fuel mixture formed by mixing the fuel vaporized by the vaporization means and the primary air. An elongated strip-shaped burner head 4 extending left and right when viewed from the front, an ignition means including an ignition plug 14 for igniting a mixture gas ejected from the flame holes 5, and a protective member provided on one side of the primary flame 6. From the flame plate 15 A secondary air flow passage including a flame holding member, a secondary air flow port 9 through which secondary air that supplies the primary flame 6 and forms a secondary flame flows, and the secondary air flow port 9 Secondary air 10 supplied from the secondary air flow passage
Is provided in the vicinity of the primary flame 6 and a secondary air outlet 12 that blows out from a position facing the flame holding plate 15, and all or part of the secondary air outlet 12 is formed of the flame holding plate 15. By setting the position above the upper end of the flame member, the following effects can be obtained. Secondary air 10
Since the secondary flame 16 is forcibly supplied to the secondary air, the secondary flame 16 is shortened, and the combustion apparatus can be made compact. Further, since all of the secondary air outlets 12 are located above the upper end of the flame holding member made of the flame holding plate 15, the primary flame 6 is cooled by the flame holding member made of the flame holding plate 15, and as a result, It is possible to suppress the generation of NOx generated in the primary flame 6. Also,
By lowering the temperature of the primary flame 6, it is possible to prevent deformation or damage around the burner head 4 or occurrence of flashback.

Embodiment 5. A fifth embodiment according to the present invention will be described with reference to FIGS. 9 and 10. 9 is a sectional view of a main portion showing a structure of a combustion apparatus according to a fifth embodiment of the present invention, and FIG. 10 is a sectional view taken along line XX thereof. In the fifth embodiment, the configuration other than the unique configuration described here has the same configuration as the configurations in the first to fourth embodiments described above, and exhibits the same operation. . In the drawings, the same reference numerals indicate the same or corresponding parts.

In FIGS. 9 and 10, reference numeral 18 denotes a heat recovery wall composed of an upright plate-shaped member provided laterally opposite the primary flame 6 between the plurality of flame holes 5 on the burner head 4. . In the fifth embodiment, the heat recovery wall 18 is installed between the flame holes 5 on the burner head 4. For this reason,
The primary flame 6 contacts the heat recovery wall 18, and the heat of the flame is transmitted to the heat recovery wall 18. Therefore, the primary flame 6 is cooled and N
Generation of Ox can be suppressed.

The shape of the flame hole 5 is not limited to the rectangular shape, and various shapes such as a circular shape are possible.

According to the fifth embodiment of the present invention, in the structure of the first to fourth embodiments, a heat recovery wall is provided between the flame holes 5 on the burner head 4 having a plurality of flame holes 5. By providing the heat recovery member consisting of 18,
The following effects can be achieved. Since the heat recovery member composed of the heat recovery wall 18 is provided between the flame holes 5 on the burner head 4, the heat of the primary flame 6 is transmitted to the heat recovery member composed of the heat recovery wall 18, and is cooled to generate NOx. Can be suppressed.

Sixth Embodiment A sixth embodiment according to the present invention will be described with reference to FIGS. FIG. 11 shows
FIG. 12 is a sectional view of a main portion showing a structure of a combustion apparatus according to a sixth embodiment of the present invention, and FIG. 12 is a sectional view taken along line XII-XII thereof. FIG. 13 is a schematic diagram showing a model of the catalytic reaction in the sixth embodiment according to the present invention. 14
FIG. 9 is a characteristic comparison diagram based on test results between the sixth embodiment according to the present invention and a conventional example. In the sixth embodiment,
The configuration other than the specific configuration described here has the same configuration as the configuration in the first to fifth embodiments described above and has the same operation. In the drawings, the same reference numerals indicate the same or corresponding parts.

In FIGS. 11 and 12, 20 is a catalyst provided inside the burner head 4. In the sixth embodiment, the catalyst 20 for oxidizing the air-fuel mixture generated from the vaporized kerosene fuel and the primary air is arranged inside the burner head 4 in the first to fifth embodiments. Part of the air-fuel mixture is partially oxidized by the oxidation catalyst,
Carbon monoxide (hereinafter referred to as CO) and carbon dioxide (hereinafter referred to as CO ₂ ) which is an inert gas are generated.
The air-fuel mixture remaining without reacting with the catalyst 20 forms a primary flame 6 in the flame hole 5, but the combustion reaction becomes inactive due to the presence of CO and CO ₂ , and the primary flame temperature and the secondary flame The temperature drops. As a result, generation of NOx can be suppressed.

FIG. 13 shows in model form that CO and CO ₂ are produced by the partial oxidation reaction of the air-fuel mixture by the catalyst 20.

FIG. 14 shows NO in the sixth embodiment.
6 is a characteristic diagram showing the relationship between the x emission characteristic and the temperature of the catalyst 20. FIG. For comparison, the figure also shows the NOx emission characteristics when the catalyst 20 is not provided. The figure shows the characteristics when the heating output (combustion amount) is 4 kW. Here, an example in which a honeycomb-shaped catalyst supporting a noble metal (palladium) is used as the catalyst 20 is shown.

When the catalyst 20 is not provided, the NOx concentration is about 1
It is 30 ppm. When the catalyst 20 is installed, the catalyst 20
If the temperature is about 450 ° C, the NOx emission concentration is about 125
It is ppm. When the temperature of the catalyst 20 is about 650 ° C., the NOx emission concentration drops to 91 ppm. This is because the catalyst reaction rate increases as the catalyst temperature rises, and CO and CO
_A large amount of ₂ is generated, the combustion reaction becomes more inactive, and the flame temperature decreases. As a result, the generation of NOx was suppressed.

The catalyst temperature can be adjusted by selecting the volume of the catalyst, the type of the catalyst and the amount of the catalyst.

According to the sixth embodiment of the present invention, the following effects are obtained by providing the catalyst 20 for oxidizing the air-fuel mixture inside the burner head 4 in the configurations of the first to fifth embodiments. Can be played. Since the catalyst 20 that oxidizes the air-fuel mixture generated from the vaporized kerosene fuel and the primary air is arranged inside the burner head 4,
Part of the air-fuel mixture is partially oxidized by the catalyst 20 and CO
And CO ₂ are generated, the combustion reaction becomes inactive, and the primary flame temperature and the secondary flame temperature decrease. As a result, generation of NOx can be suppressed.

Embodiment 7. A seventh embodiment according to the present invention will be described with reference to FIGS. Figure 15 shows
16 is a sectional view of a main portion showing a combustion apparatus according to a seventh embodiment of the present invention, and FIG. 16 is a sectional view taken along line XVI-XVI thereof. In the seventh embodiment, the configuration other than the specific configuration described here is the same as that of the first embodiment described above.
It has the same configuration as that of the sixth embodiment and has the same operation. In the drawings, the same reference numerals indicate the same or corresponding parts.

In the seventh embodiment, the sixth embodiment described above is adopted.
In, the catalyst 20 was placed in contact with the side wall forming the burner head 4. As a result, the heat is recovered from the flame to heat the catalyst 20, so that it is not necessary to increase the volume or the amount of the catalyst to increase the temperature of the catalyst 20, and the cost increase due to the use of the catalyst is prevented. To do.

According to the seventh embodiment of the present invention, in the structure of the first to sixth embodiments, the catalyst 20 installed inside the burner head is brought into contact with the side wall of the burner head 4. The following effects can be obtained by installing the above. Since the catalyst 20 is installed in contact with the burner head 4, heat is recovered from the flame to heat the catalyst 20, and it is necessary to increase the volume and the amount of the catalyst 20 to increase the temperature of the catalyst 20. In addition, increase in cost due to use of catalyst is prevented.

Embodiment 8. The eighth embodiment according to the present invention will be described with reference to FIGS. Figure 17
FIG. 18 is a sectional view of a main portion showing a structure of a combustion apparatus according to Embodiment 8 of the present invention, and FIG. 18 is a sectional view taken along line XVIII-XVIII thereof. The structure of the eighth embodiment other than the specific structure described here has the same structure as the structure of the sixth embodiment described above, and exhibits the same operation. In the drawings, the same reference numerals indicate the same or corresponding parts.

In the eighth embodiment, the sixth embodiment described above is adopted.
In the above, a part of the catalyst 20 is provided in the flame hole 5 portion communicating with the inside of the burner head 4. As a result, the primary flame comes into contact with the catalyst 20 and the catalyst 20 is heated. Therefore, it is not necessary to increase the volume or the amount of the catalyst to increase the temperature of the catalyst 20, which results in an increase in cost due to the use of the catalyst. To prevent.

According to the eighth embodiment of the present invention, in the structure of the sixth embodiment, a flame hole 5 for communicating a part of the catalyst 20 installed inside the burner head 4 to the inside of the burner head 4. By providing the portion, the following effects can be obtained. Since a part of the catalyst 20 is provided in communication with the burner head, the catalyst 20 is heated by the primary flame 6, and it is not necessary to increase the volume or the amount of the catalyst 20 to raise the temperature of the catalyst 20, The cost increase due to the use of a catalyst is prevented.

Ninth Embodiment The ninth embodiment according to the present invention will be described with reference to FIGS. FIG. 19 shows
20 is a sectional view of a main portion showing a structure of a combustion apparatus according to a ninth embodiment of the present invention, FIG. 20 is a sectional view taken along line XX-XX thereof, and FIG. 21 is a sectional view taken along line XXI-XXI of FIG. In the ninth embodiment, the configuration other than the peculiar configuration described here has the same configuration as the configuration in the fifth embodiment described above, and exhibits the same operation. In the drawings, the same reference numerals indicate the same or corresponding parts.

In FIGS. 19 to 21, reference numeral 18 is a heat recovery wall 18 communicating with the burner head 4. In the ninth embodiment, the lower portion of the heat recovery wall 18 in the fifth embodiment is inserted into the burner head 4, and the surface of the heat recovery wall 18 and the internal space of the burner head 4 are provided so as to communicate with each other. The catalyst 20 is provided on the surface of the heat recovery wall 18 inside the burner head 4. As a result, the heat of the primary flame 6 is transmitted through the heat recovery wall 18 and the catalyst 20 is heated. Therefore, it is not necessary to increase the volume or the amount of the catalyst to increase the temperature of the catalyst 20. Prevent cost increase.

According to the ninth embodiment of the present invention, in the structure of the fifth embodiment, the heat recovery member composed of the heat recovery wall 18 is communicated with the inside of the burner head 4, and the heat inside the burner head 4 is heated. By providing the heat recovery member including the recovery wall 18 with the catalyst 20 for oxidizing the air-fuel mixture,
The following effects can be achieved. Since a part of the catalyst 20 is provided so as to communicate with the burner head 4, the catalyst 2 is generated by the primary flame 6.
No. 0 is heated, and it is not necessary to increase the volume or the amount of the catalyst 20 to raise the temperature of the catalyst 20, and the cost increase due to the use of the catalyst is prevented.

[0066]

According to the first aspect of the invention, all of the secondary air outlets for forcibly supplying the secondary air to the primary air are located below the upper end of the flame holding plate. The next flame is cooled by the flame holding plate, NOx generation can be suppressed, deformation and damage around the burner head or occurrence of flashback can be prevented, and the combustion device can be made compact.

According to the second aspect of the invention, all or part of the secondary air outlet for forcibly supplying the secondary air to the primary air is located at the position above the upper end of the flame holding plate. The next flame is cooled by the flame holding plate, NOx generation can be suppressed, deformation and damage around the burner head or occurrence of flashback can be prevented, and the combustion device can be made compact.

According to the third aspect of the invention, the secondary air outlet for forcibly supplying the secondary air to the primary air is provided at a position facing the flame stabilizing plate, and the entire secondary air outlet is provided. Since the secondary flame is located below the upper end of the flame holding plate, the secondary flame is cooled by the flame holding plate, NOx generation can be suppressed, and deformation or damage around the burner head or occurrence of flashback can be prevented. In addition, the combustion device can be made compact.

According to the fourth aspect of the invention, a secondary air outlet for forcibly supplying the secondary air to the primary air is provided at a position facing the flame holding plate, or all of the secondary air outlets are provided. Since part of the flame is above the upper edge of the flame holding plate, the primary flame is cooled by the flame holding plate and NOx generation can be suppressed, preventing deformation or damage around the burner head or occurrence of flashback. In addition, the combustion device can be made compact.

According to the fifth invention, in the first to fourth inventions, since the heat recovery wall is provided between the flame holes on the burner head, the heat of the primary flame is transmitted to the heat recovery wall and is cooled. ,
Generation of NOx can be suppressed.

According to the sixth invention, in the first to fifth inventions, the catalyst for oxidizing the air-fuel mixture generated from the vaporized kerosene fuel and the primary air is arranged inside the burner head. Part of the air-fuel mixture is partially oxidized by the catalyst, CO and CO ₂ are produced, and the combustion reaction becomes inactive.
The secondary flame temperature and the secondary flame temperature decrease. as a result,
Generation of NOx can be suppressed.

According to the seventh invention, in the sixth invention, since the catalyst is installed in contact with the side wall constituting the burner head, the heat is recovered from the flame to heat the catalyst, and the temperature of the catalyst is increased. Therefore, it is not necessary to increase the volume or the amount of the catalyst to increase the temperature, and the cost increase due to the use of the catalyst is prevented.

According to the eighth invention, in the sixth invention, since a part of the catalyst is provided in communication with the burner head,
The catalyst is heated by the primary flame, and it is not necessary to increase the volume or the amount of the catalyst to raise the temperature of the catalyst, and the cost increase due to the use of the catalyst is prevented.

According to the ninth invention, in the fifth invention, the heat recovery wall is provided in communication with the burner head, and the heat recovery wall inside the burner head is provided with the catalyst. The catalyst is heated along the recovery wall, and it is not necessary to increase the volume or the amount of the catalyst to raise the temperature of the catalyst, and the cost increase due to the use of the catalyst is prevented.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structure of a combustion apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1 showing the configuration of the combustion device according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing a structure of a combustion device according to a second embodiment of the present invention.

FIG. 4 is a characteristic comparison diagram based on test results of the first and second embodiments according to the present invention and a conventional example.

FIG. 5 is a sectional view showing a structure of a combustion apparatus according to a third embodiment of the present invention.

FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 5 showing the configuration of the combustion device in Embodiment 3 according to the present invention.

FIG. 7 is a sectional view showing the structure of a combustion apparatus according to Embodiment 4 of the present invention.

FIG. 8 is a characteristic comparison diagram based on test results between the third and fourth embodiments of the present invention and a conventional example.

FIG. 9 is a sectional view showing a structure of a combustion apparatus according to a fifth embodiment of the present invention.

FIG. 10 is a sectional view taken along line XX of FIG. 9 showing the structure of the combustion apparatus according to the fifth embodiment of the present invention.

FIG. 11 is a sectional view showing a structure of a combustion apparatus according to Embodiment 6 of the present invention.

FIG. 12 is a sectional view taken along line XII-XII in FIG. 9 showing the structure of the combustion apparatus according to the sixth embodiment of the present invention.

FIG. 13 is a model view showing the catalytic reaction in the sixth embodiment according to the present invention.

FIG. 14 is a characteristic comparison diagram based on test results between the sixth embodiment according to the present invention and a conventional example.

FIG. 15 is a sectional view showing the structure of a combustion apparatus according to Embodiment 7 of the present invention.

FIG. 16 is a sectional view taken along the line XVI-XVI in FIG. 13 showing the structure of the combustion apparatus according to the seventh embodiment of the present invention.

FIG. 17 is a sectional view showing the structure of a combustion apparatus according to Embodiment 8 of the present invention.

FIG. 18 is a cross-sectional view taken along line XVIII-XVIII in FIG. 15 showing the structure of the combustion apparatus according to Embodiment 8 of the present invention.

FIG. 19 is a sectional view showing the structure of a combustion apparatus according to Embodiment 9 of the present invention.

FIG. 20 is a cross-sectional view taken along line XX-XX in FIG. 19 showing the structure of the combustion apparatus according to Embodiment 9 of the present invention.

FIG. 21 is a cross-sectional view taken along line XXI-XXI of FIG. 20 showing the structure of the combustion apparatus according to Embodiment 9 of the present invention.

FIG. 22 is a partial cross-sectional view showing the configuration of a conventional combustion device.

[Explanation of symbols]

1 vaporization chamber, 2 electric heater, 3 throttle part, 4 burner head, 5 flame hole, 61st flame, 7 branching chamber, 8 air nozzle, 9 secondary air flow port, 10 secondary air, 12
Secondary air outlet, 13 Fuel supply pipe, 14 Ignition plug, 15 Flame retaining plate, 16 Secondary flame, 17 Combustion cylinder, 1
8 heat recovery walls, 20 catalysts.

Continued front page    (72) Inventor Minoru Sato             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. (72) Inventor Hidenori Ozeki             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. (72) Inventor Norio Mitsuda             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. F-term (reference) 3K023 KA03 KC01 KD01                 3K052 AA06 AB06 AC05 DB08 EA08                       FA01 GA06 GA10 GB06 GB10                       GD00 GE07

Claims (9)

[Claims] 1. A vaporizing means for vaporizing liquid fuel, a liquid fuel supplying means for supplying the liquid fuel to the vaporizing means, and a first air supplying means for supplying primary air to the vaporizing means,
A slender strip burner head having a flame hole communicating with the vaporizing means and ejecting an air-fuel mixture formed by mixing the fuel vaporized by the vaporizing means and the primary air to form a primary flame. An igniting means for igniting an air-fuel mixture ejected from the flame holes, a flame holding member provided around the primary flame, and secondary air which supplies the primary flame to form a secondary flame. And a secondary air flow passage for discharging the secondary air supplied from the secondary air flow passage to the vicinity of the primary flame 2
And a secondary air outlet, wherein all of the secondary air outlets are located below the upper end of the flame holding member. 2. A vaporizing means for vaporizing liquid fuel, a liquid fuel supplying means for supplying the liquid fuel to the vaporizing means, and a first air supplying means for supplying primary air to the vaporizing means.
A slender strip burner head having a flame hole communicating with the vaporizing means and ejecting an air-fuel mixture formed by mixing the fuel vaporized by the vaporizing means and the primary air to form a primary flame. An igniting means for igniting an air-fuel mixture ejected from the flame holes, a flame holding member provided around the primary flame, and secondary air which is supplied to the primary flame to form a secondary flame. And a secondary air flow passage for discharging the secondary air supplied from the secondary air flow passage to the vicinity of the primary flame 2
And a secondary air outlet, wherein all or part of the secondary air outlet is located at a position higher than or equal to the upper end of the flame holding member. 3. Vaporizing means for vaporizing liquid fuel, liquid fuel supplying means for supplying liquid fuel to the vaporizing means, and first air supplying means for supplying primary air to the vaporizing means,
An elongated strip-shaped burner head having a flame hole communicating with the vaporizing means and ejecting an air-fuel mixture formed by mixing the fuel vaporized by the vaporizing means with the primary air to form a primary flame. An igniting means for igniting an air-fuel mixture ejected from the flame holes, a flame holding member provided on one side surface of the primary flame, and secondary air supplied to the primary flame to form a secondary flame. A secondary air flow passage that circulates; and a secondary air outlet that blows out secondary air supplied from the secondary air flow passage from a position facing the flame holding member in the vicinity of the primary flame. A combustion apparatus, wherein all of the secondary air outlets are located below the upper end of the flame holding member. 4. A vaporizing means for vaporizing liquid fuel, a liquid fuel supplying means for supplying the liquid fuel to the vaporizing means, and a first air supplying means for supplying primary air to the vaporizing means.
A slender strip burner head having a flame hole communicating with the vaporizing means and ejecting an air-fuel mixture formed by mixing the fuel vaporized by the vaporizing means and the primary air to form a primary flame. An ignition means for igniting an air-fuel mixture ejected from the flame holes, a flame holding member provided on one side surface of the primary flame, and secondary air supplied to the primary flame to form a secondary flame. The secondary air flow passage that circulates and the secondary air supplied from the secondary air flow passage are blown out in the vicinity of the primary flame from a position facing the flame holding member, and all or part of the flame holding member. And a secondary air outlet located at a position above the upper end of the combustion device. 5. The combustion apparatus according to claim 1, wherein a heat recovery member is provided between the flame holes on the burner head having a plurality of flame holes. 6. The combustion apparatus according to claim 1, wherein a catalyst for oxidizing the air-fuel mixture is provided inside the burner head. 7. The combustion apparatus according to claim 6, wherein the catalyst installed inside the burner head is installed in contact with the burner head. 8. The combustion apparatus according to claim 6, wherein a part of the catalyst installed inside the burner head is provided in a flame hole portion communicating with the inside of the burner head. 9. The combustion apparatus according to claim 5, wherein the heat recovery member is connected to the inside of the burner head, and the heat recovery member inside the burner head is provided with a catalyst for oxidizing the air-fuel mixture. .