JPH08200615A - Liquid fuel burner - Google Patents

Abstract

PURPOSE: To suppress the generation of CO while realizing low NOX combustion by so coupling a cylinder to a vaporizing column for mixing a vaporized gas with primary air as to cover a primary burner port, providing a secondary burner port at the end of the cylinder, and providing a secondary air supply unit on the outer periphery. CONSTITUTION: Mixed gas of a vaporized gas premixed in a vaporizing cylinder 30 with primary air becomes a uniformly mixed state in the case of passing the throttle port 34A of a throttle plate 34 and a porous plate 36, injected from the primary burner ports 38 of a burner plate 37 into a primary combustion chamber 43, the injected mixed gas is ignited by a spark discharge of an ignition plug 47, and its combustion is started. A closed-end cylindrical primary combustion cylinder 42 in which a secondary burner port 44 having a plurality of secondary burner ports 45 is provided at the end is coupled to the upper end of the cylinder 30, the upper space of the plate 37 of the cylinder 30 is covered with the cylinder 42, and the secondary air from a secondary air port 40 is supplied to the outer periphery of the cylinder 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid fuel combustion apparatus for vaporizing and burning liquid fuel such as kerosene, and particularly to low NO
The present invention relates to a liquid fuel combustion device capable of realizing x combustion.

[0002]

2. Description of the Related Art As shown in FIG. 5, a conventional liquid fuel combustion apparatus has a bottomed cylinder in which a vaporization electric heater 3 is embedded in a peripheral wall of a burner case 2 to which combustion air from a blower 1 is supplied. The vaporization cylinder 4 in the shape of a cylinder is housed. This vaporization cylinder 4 is provided with an air introduction port 5 at the lower part of the peripheral wall, and a diaphragm plate 7 having a diaphragm port 6 and a perforated plate 8 are mounted inside, and the vaporization cylinder 4 above the perforated plate 8 is provided with an opening. A burner plate 10 having a large number of flame holes 9 is mounted. 11 is a fuel nozzle, 12 is a spark plug, 13 is a frame rod, 14 is a secondary air jet plate having a plurality of secondary air holes 15, 16 is a vaporization tube 4 and a burner case 2 under the secondary air jet plate 14. An air storage chamber formed between and is a combustion cylinder 17 connected on the burner case 2.

In the above structure, the vaporizing electric heater 3 is used.
When the primary air is supplied from the air introduction port 5 and the liquid fuel is supplied from the fuel nozzle 11 to the inside of the vaporization cylinder 4 which is heated to a high temperature by, the liquid fuel is vaporized and mixed with the primary air. The mixed gas, after passing through the throttle opening 6 of the throttle plate 7 and the perforated plate 8, is ejected from a large number of flame holes 9 of the burner plate 10. The mixed gas ejected from the flame holes 9 is ignited by the ignition plug 12 to form a flame on the burner plate 10 and burn. On the other hand, the secondary air ejection plate 14
The secondary air ejected from the secondary air hole 15 is supplied to the flame and promotes secondary combustion.

[0004]

By the way, in the above-mentioned conventional liquid fuel combustion apparatus, the secondary air flows into the primary combustion flame of the flame, and the secondary air flowing into the primary combustion flame is heated to the temperature of the primary combustion flame. Enhances nitrogen oxides (NOx)
There is a problem that promotes the generation of.

The present invention has been made in view of the above-mentioned circumstances, and it is possible to provide a liquid fuel combustion apparatus capable of realizing low NOx combustion, and to suppress generation of CO while realizing low NOx combustion. The purpose is to do.

[0006]

According to the present invention, a vaporization cylinder for vaporizing a liquid fuel and mixing the vaporized gas with the primary air, and a vaporization cylinder provided in the vaporization cylinder for ejecting the mixed gas in the vaporization cylinder A primary flame hole to be burned, a cylinder connected to the vaporizing cylinder so as to cover the primary flame hole, a secondary flame hole provided at the tip of the cylinder, and a secondary flame on the outer circumference of the cylinder. The secondary air supply unit supplies the secondary air.

Further, according to the present invention, a vaporization cylinder for vaporizing the liquid fuel and mixing the vaporized gas with the primary air, and a primary flame provided in the vaporization cylinder for ejecting and burning the mixed gas in the vaporization cylinder Supplying secondary air to the hole, the cylinder connected to the vaporization cylinder so as to cover the primary flame hole, the secondary flame hole provided at the tip of this cylinder, and the outer periphery of the cylinder. And a flame spread resistance plate provided to face the secondary flame hole portion.

Further, according to the present invention, the vaporizing cylinder for vaporizing the liquid fuel and mixing the vaporized gas with the primary air, and the primary flame provided in the vaporizing cylinder for ejecting and burning the mixed gas in the vaporizing cylinder. Supplying secondary air to the hole, the cylinder connected to the vaporization cylinder so as to cover the primary flame hole, the secondary flame hole provided at the tip of this cylinder, and the outer periphery of the cylinder. The secondary air supply unit and the flame spreading resistance plate provided so as to face the secondary flame hole portion are provided, and the flame spreading resistance plate has a size substantially the same as or slightly larger than the cylindrical body.

Further, according to the present invention, the vaporizing cylinder for vaporizing the liquid fuel and mixing the vaporized gas with the primary air, and the primary flame provided in the vaporizing cylinder for ejecting and burning the mixed gas in the vaporizing cylinder. Supplying secondary air to the hole, the cylinder connected to the vaporization cylinder so as to cover the primary flame hole, the secondary flame hole provided at the tip of this cylinder, and the outer periphery of the cylinder. And a secondary air supply unit that is provided, and the cylinder body is attached in close contact with the vaporization cylinder.

Further, according to the present invention, a vaporization cylinder for vaporizing the liquid fuel and mixing the vaporized gas with the primary air, and a primary flame provided in the vaporization cylinder for ejecting and burning the mixed gas in the vaporization cylinder Supplying secondary air to the hole, the cylinder connected to the vaporization cylinder so as to cover the primary flame hole, the secondary flame hole provided at the tip of this cylinder, and the outer periphery of the cylinder. And a secondary air supply unit for controlling the temperature, and the cylindrical body is made of a heat-resistant metal material having excellent heat absorption.

Further, according to the present invention, the vaporizing cylinder for vaporizing the liquid fuel and mixing the vaporized gas with the primary air, and the primary flame provided in the vaporizing cylinder for ejecting and burning the mixed gas in the vaporizing cylinder. Supplying secondary air to the hole, the cylinder connected to the vaporization cylinder so as to cover the primary flame hole, the secondary flame hole provided at the tip of this cylinder, and the outer periphery of the cylinder. And a secondary air supply section, and the secondary flame hole portion has a plurality of radially formed secondary flame holes.

[0012]

With this structure, the secondary air supplied from the secondary air supply section flows along the outer periphery of the cylinder connected to the vaporizing cylinder and is formed in the secondary flame hole at the tip of the cylinder. It will be supplied to the secondary combustion flame and will not flow near the primary flame hole. Therefore, the secondary air does not flow into the primary combustion flame formed in the cylinder, the maximum temperature of the primary combustion flame,
In addition, the average temperature can be kept low and NOx
Can be reduced.

In the liquid fuel combustion apparatus of claim 2,
It is possible to suppress the maximum temperature of the primary combustion flame and the average temperature to a low level, and not only can the amount of NOx generated be reduced, but since a flame spreading resistance plate is provided facing the secondary flame hole, The secondary combustion flame formed in the secondary flame hole part is spread laterally by the flame spreading resistance plate to stabilize the secondary combustion flame and to bring the secondary combustion flame into contact with the secondary air flowing around the outer periphery of the cylinder. As a result, it is possible to re-combust and reduce the amount of CO generated.

In the liquid fuel combustion apparatus of claim 3,
It is possible to suppress the maximum temperature and average temperature of the primary combustion flame to a low level, and not only to reduce the amount of NOx generated, but also to use a flame-spreading resistance plate that is installed facing the secondary flame hole, Since it is made to be approximately the same size as or slightly larger than the body, the secondary combustion flame formed in the secondary flame hole part is spread outside the cylinder by the flame spreading resistance plate and stable combustion is performed, while the outer circumference of the cylinder is It is possible to forcibly contact the flowing secondary air to reburn it efficiently, and to further reduce the generation of CO.

In the liquid fuel combustion apparatus of claim 4,
It is possible to keep the maximum temperature and average temperature of the primary combustion flame low, and not only can the amount of NOx produced be reduced, but the primary combustion flame can be It is possible to efficiently transfer the heat of the heated cylindrical body to the vaporization cylinder, and reduce the power consumption of the heater for heating the vaporization cylinder.

In the liquid fuel combustion apparatus of claim 5,
The maximum temperature and average temperature of the primary combustion flame can be kept low, and the amount of NOx produced can be reduced, and the cylinder is made of a heat-resistant metal material with excellent heat absorption. Therefore, the heat of the primary combustion flame can be efficiently absorbed by the cylindrical body, and the maximum temperature and the average temperature of the primary combustion flame can be suppressed to a further low level, and the generation of NOx can be further reduced.

In the liquid fuel combustion apparatus of claim 6,
It is possible to suppress the maximum temperature and average temperature of the primary combustion flame to a low level, and not only to reduce the amount of NOx generated, but also the secondary flame holes are formed by a plurality of secondary flame holes that are radially formed. Therefore, the secondary combustion flame formed in the secondary flame hole portion can be prevented from deviating, the contact between the secondary combustion flame and the secondary air can be made uniform, and the re-combustion effect is improved.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings of FIGS. In FIG. 1, 20 is a blower, and this blower 20 includes a blower fan 21 and a motor 2.
2 and a casing 23. Further, the casing 23 is fitted into the outer case 23B, which is an end plate 23A also serving as a support plate, an outer case 23B to which an air supply pipe 24 for introducing combustion air is connected, and an outer case 23B. It is composed of a combined inner case 23C and a heat-resistant rubber annular packing 23D interposed between the end plate 23A and the outer case 23B.

A burner case 26, which is formed into a cylindrical shape with a bottom by deep drawing, is connected to the upper surface of the end plate 23A, which is a component of the casing 23, through a sealing material (not shown). On the case 26, a secondary combustion cylinder 2 having a secondary combustion chamber 28 inside through a sealing material 27 is provided.
9 is connected, and a heat exchanger (not shown) is connected to the tip of the secondary combustion tube 29. Further, a plurality of vent holes 25, 25 are arranged in an annular shape in the outer peripheral portion of the bottom wall 26A of the burner case 26 and the end plate 23A.

In the lower center of the burner case 26,
A vaporization cylinder 30 made of aluminum die cast and formed in a cylindrical shape with a bottom so as to surround the outer periphery with a burner case 26 is accommodated and fixed. The vaporization cylinder 30 has an electric heater 31 for vaporization embedded in the peripheral wall thereof, and the electric heater 3 for vaporization is also provided.
An air inlet 32 for introducing and supplying the primary air for combustion into the vaporization cylinder 30 is provided on the peripheral wall at a position lower than 1 integrally with the vaporization cylinder 30 and in the tangential direction of the vaporization cylinder 30. The air inlet 32 is formed so as to shrink like a funnel from the outside to the inside.

Reference numeral 33 denotes a fuel nozzle for jetting and supplying the liquid fuel (kerosene) sent from a fuel pump (not shown) into the vaporization cylinder 30. The fuel nozzle 33 penetrates the peripheral wall of the burner case 26. The air is introduced into the burner case 26 and is inserted into the air introduction port 32, and the tip ejection port faces the inside of the vaporization cylinder 30 with the tip thereof facing downward.

Reference numeral 34 is a diaphragm plate mounted inside the vaporization cylinder 30 above the air inlet 32 and having a central diaphragm opening 34A. Reference numeral 35 is a baffle plate arranged below the diaphragm opening 34A of the diaphragm plate 34. A perforated plate provided on the diaphragm plate 34,
Reference numeral 37 is a disc-shaped burner plate provided on the perforated plate 36 so as to cover the upper opening of the vaporization cylinder 30. The burner plate 37 is made of fine ceramics such as petalite which is resistant to heat shock and excellent in impact resistance, and has a hole diameter of about 1 to 1.5 on its outer peripheral portion.
A plurality of mm-sized primary flame holes 38, 38 are arranged side by side in a plurality of rows in the circumferential direction.

Reference numeral 39 denotes a ring-shaped secondary air ejection plate provided between the upper portion of the vaporization cylinder 30 and the inner peripheral surface of the peripheral wall of the burner case 36. The secondary air ejection plate 39 is the vaporization cylinder 30. An inwardly-facing inclined surface 39A is provided on a nearby inner peripheral portion, and a plurality of secondary air holes 40, 40 are annularly arranged at substantially equal intervals in the inwardly-facing inclined surface 39A. Further, on the outer peripheral edge of the secondary air jetting plate 39, a cylindrical wall 41 that is internally fitted to the upper portion inside the burner case 36 is provided so as to rise integrally, and the upper flange portion 41A of the cylindrical wall 41 is provided. The cylindrical wall 41 and the secondary air ejection plate 39 are fixed in the burner case 26 by sandwiching the sealant 27 with the upper flange 26B formed at the upper end of the burner case 26.

Thus, in the burner case 26 below the secondary air ejection plate 39, there is formed a donut-shaped air storage chamber X to which the combustion air from the blower 20 is supplied via the ventilation holes 25, 25. As shown in FIG. 1, an outer open end of an air introduction port 32 provided on the side wall of the vaporization cylinder 30 faces the air storage chamber X in an open state.

Reference numeral 42 denotes the burner plate 3 of the vaporizing cylinder 30.
7 is a primary combustion cylinder having a cylindrical shape in which the lower part is externally fitted to the outer periphery of the upper end portion of the vaporization cylinder 30 so as to cover the upper space of 7. It is made of a heat-resistant aluminum alloy of excellent aluminum-manganese system, and its lower end is attached in close contact with the outer surface of the vaporization cylinder 30, and the inside thereof forms a primary combustion chamber 43. In addition, the secondary combustion holes 4 and 40 of the secondary air ejection plate 39 are connected to the primary combustion cylinder 4
The height H to the upper end of 2 can be arbitrarily set within the range of about 30 to 70 mm.

FIG. 4 shows the maximum combustion amount of about 3000 Kcal.
In the liquid fuel combustion device set to / h, the height H from the secondary air holes 40, 40 to the upper end of the primary combustion cylinder 42
Shows the results of a combustion experiment using five samples of the primary combustion cylinders 42 set to different heights of about 20 mm to about 60 mm by about 10 mm, with the combustion amount being substantially constant. According to this experimental result, the higher the height H is, the higher the effect of blocking the secondary air with respect to the primary combustion flame F and the NOx generation amount can be reduced, but the maximum combustion amount is about 3000 Kcal.
In the liquid fuel combustion device set to / h, considering the practicality, it is desirable to set the height H to about 40 to 60 mm.

A secondary flame hole portion 44 is formed on the top surface of the primary combustion cylinder 42. The secondary flame hole portion 44 is formed to have a low center, and has a tapered surface 44A that widens from the central portion to a tapered shape at a wide angle. A secondary flame hole 45 is provided on the tapered surface 44A. As shown in FIG. 3, the secondary flame holes 45 are radially provided by being divided into a plurality of parts along the entire circumference of the tapered surface 44A. Further, on the upper surface of the secondary flame hole portion 44 substantially at the center thereof, there is mounted a flame spreading resistance plate 46 having a divergent taper whose outer diameter is substantially the same as or slightly larger than that of the primary combustion cylinder 42. The flame spreading resistance plate 46 faces the secondary flame hole 45 with a predetermined space. Reference numeral 47 is a spark plug, and 48 is a frame rod.

In the above structure, the vaporization electric heater 3 is used.
When the vaporization cylinder 30 rises to the vaporization temperature of the liquid fuel by energizing No. 1, the motor 22 and the fuel pump (not shown) of the blower 20 are activated, and the liquid fuel is supplied from the fuel nozzle 33 into the vaporization cylinder 30. The combustion air from the blower 20 supplied to the air storage chamber X through the ventilation hole 25 from the air inlet 32 is supplied to the inside of the vaporization cylinder 30 as primary air. Here, the liquid fuel supplied into the vaporization cylinder 30 is dispersed as fine particles due to the synergistic effect of the primary air flow ejected from the air introduction port 32 and the discharge pressure of the fuel pump, and the inner peripheral surface of the vaporization cylinder 30. And contact with the inner bottom surface to be vaporized.

The mixed gas of the vaporized gas and the primary air premixed inside the vaporization cylinder 30 becomes a uniform mixed state when passing through the throttle port 34A of the throttle plate 34 and the perforated plate 36, and the burner plate 37. From the primary flame holes 38, 38, the gas is ejected into the primary combustion chamber 43, and the ejected mixed gas is ignited by the spark discharge of the ignition plug 47 to start combustion. On the other hand, a part of the combustion air supplied to the air storage chamber X is
The secondary air holes 40, 40 are ejected from the secondary air holes 40 to rise as secondary air in the annular space around the outer periphery of the primary combustion cylinder 42.

With this combustion start, in strong combustion,
The primary combustion flame F is formed on the burner plate 37 to perform the primary combustion. The primary combustion in the primary combustion chamber 43 is
The combustion is not completed because the combustion is in the oxygen-deficient state where the secondary air is hardly supplied, and the combustion gas containing a large amount of unburned gas flows out of the primary combustion chamber 43 through the secondary flame holes 45. The flowing out combustion gas is guided by the flame spreading resistance plate 46 to flow laterally between the secondary flame hole portion 44 and the flame spreading resistance plate 46, and comes into contact with the secondary air flowing on the outer periphery of the primary combustion cylinder 42. Then, secondary combustion is performed. At this time, the secondary combustion flame FF
Are formed between the secondary flame hole portion 44 and the flame spread resistance plate 46 and on the sides thereof.

Further, since the primary combustion flame F formed on the burner plate 37 heats the upper portions of the primary combustion cylinder 42 and the vaporization cylinder 30, the heat is conducted to the lower part of the vaporization cylinder 30 and the vaporization part is generated. Maintain a vaporizable temperature. Therefore, even if the power supply to the vaporization electric heater 31 is stopped when a predetermined time has elapsed from the start of combustion, vaporization and combustion of the liquid fuel continue.

According to this embodiment, a plurality of secondary flame holes 45,
A primary combustion cylinder 42 having a cylindrical shape with a secondary flame hole 44 having 45 at the tip is connected to the upper end of the vaporization cylinder 30, and the primary combustion cylinder 42 is arranged above the burner plate 37 of the vaporization cylinder 30. Since the space is covered and the secondary air from the secondary air hole 40 is supplied to the outer periphery of the primary combustion cylinder 42, the secondary air ejected from the secondary air hole 40 rises on the outer periphery of the primary combustion cylinder 42. However, it hardly flows into the primary combustion chamber 43 and is supplied to the secondary combustion flame FF formed in the secondary flame hole portion 44 at the tip portion of the primary combustion cylinder 42. Therefore, since the secondary air is not supplied to the primary combustion flame F formed on the burner plate 37, the maximum temperature of the primary combustion flame F and the average temperature can be suppressed to a low level, and the amount of NOx generated can be reduced to the conventional level. Can be significantly reduced compared to.

Further, the flame spreading resistance plate 4 having a tapering end shape is formed at a substantially central portion of the secondary flame hole portion 44 at the tip of the primary combustion cylinder 42.
6 is mounted, and the flame spreading resistance plate 46 faces the secondary flame hole 45 of the secondary flame hole portion 44 with a predetermined space,
The secondary combustion flame FF formed in the secondary flame hole portion 44 is laterally spread by the flame spreading resistance plate 46, and the secondary combustion flame FF is stabilized while the secondary combustion flame FF is kept on the outer periphery of the primary combustion cylinder 42. Can be re-burned by contacting the secondary air flowing through
This re-combustion also reduces the amount of CO generated.

Further, since the outer diameter dimension of the flame spread resistance plate 46 is set to be substantially the same as or slightly larger than the outer diameter dimension of the primary combustion cylinder 42, the secondary flame hole 44 is formed in the secondary flame hole portion 44. The combustion flame FF is spread outside the peripheral wall of the primary combustion cylinder 42 by the flame spreading resistance plate 46 to stabilize combustion,
The secondary air flowing through the outer periphery of the primary combustion cylinder 42 can be forcibly brought into contact with the secondary air to reburn it efficiently, and the generation of CO can be further reduced.

The lower end of the primary combustion cylinder 42 is the vaporization cylinder 3
Since it is attached in close contact with the outer surface of No. 0, the heat of the primary combustion cylinder 42 heated by the primary combustion flame FF to a high temperature can be efficiently conducted to the vaporization cylinder 30, and the combustion is started for a predetermined time. After the lapse of time, even if the power supply to the vaporization electric heater 31 embedded in the vaporization cylinder 30 is stopped, the vaporization cylinder 30 can be maintained at the vaporization temperature of the liquid fuel, and the vaporization electric heater 31 can be maintained.
Power consumption can be reduced.

Further, since the primary combustion cylinder 42 is made of a heat-resistant aluminum alloy of aluminum-manganese type having excellent heat absorption and thermal conductivity, the heat of the primary combustion flame FF formed inside is primary. It can be efficiently absorbed by the combustion cylinder 42 and conducted to the vaporization cylinder 30, and the maximum temperature of the primary combustion flame and the average temperature can be suppressed to a lower level.
It is possible to further reduce the generation of Ox.

Further, since the secondary flame hole portion 44 at the tip of the primary combustion cylinder 42 has a plurality of secondary flame holes 45 formed radially, the combustion gas in the primary combustion cylinder 42 is plural. The secondary flame holes 45 are dispersed and flow out. Therefore, deviation of the secondary combustion flame FF formed in the secondary flame hole portion 44 can be prevented, and the secondary combustion flame FF can be uniformly spread over the entire circumference of the primary combustion cylinder 42 in the circumferential direction, and re-combustion can be performed. The effect is improved, and the generation of CO can be further reduced.

[0038]

Since the present invention is constructed as described above, the secondary air from the secondary air supply portion is supplied to the outer periphery of the cylinder connected to the vaporizing cylinder and almost never flows into the cylinder. Therefore, it is not supplied to the primary combustion flame formed on the primary flame hole portion. Therefore, the maximum temperature and average temperature of the primary combustion flame can be suppressed to a low level, the amount of NOx generated can be greatly reduced compared to the conventional case, and low NOx combustion can be realized with a simple configuration.

In the liquid fuel combustion apparatus of claim 2,
It is possible to suppress the maximum temperature of the primary combustion flame and the average temperature to a low level, and not only can the amount of NOx generated be reduced, but since a flame spreading resistance plate is provided facing the secondary flame hole, The secondary combustion flame formed in the secondary flame hole part is spread laterally by the flame spreading resistance plate to stabilize the secondary combustion flame and to bring the secondary combustion flame into contact with the secondary air flowing around the outer periphery of the cylinder. As a result, it is possible to re-combust and reduce the amount of CO generated.

In the liquid fuel combustion apparatus of claim 3,
It is possible to suppress the maximum temperature and average temperature of the primary combustion flame to a low level, and not only to reduce the amount of NOx generated, but also to use a flame-spreading resistance plate that is installed facing the secondary flame hole, Since it is made to be approximately the same size as or slightly larger than the body, the secondary combustion flame formed in the secondary flame hole part is spread outside the cylinder by the flame spreading resistance plate and stable combustion is performed, while the outer circumference of the cylinder is It is possible to forcibly make contact with the flowing secondary air for efficient re-combustion and further reduce CO generation.

Further, in the liquid fuel combustion apparatus according to the fourth aspect, it becomes possible to suppress the maximum temperature and the average temperature of the primary combustion flame to be low, so that not only the amount of NOx generated can be reduced but also the cylindrical body Since it is attached closely to the vaporization cylinder, it is possible to efficiently transfer the heat of the cylinder heated to a high temperature by the primary combustion flame to the vaporization cylinder, and the power consumption of the heater for heating the vaporization cylinder. Can be reduced.

Further, in the liquid fuel combustion apparatus according to the fifth aspect, it becomes possible to suppress the maximum temperature and the average temperature of the primary combustion flame to be low, so that not only the amount of NOx generated can be reduced but also the cylindrical body Is made of a heat-resistant metal material with excellent heat absorption, the heat of the primary combustion flame can be efficiently absorbed by the cylinder, and the maximum temperature of the primary combustion flame and the average temperature can be kept even lower. Enabled, N
It is possible to further reduce the generation of Ox.

Further, in the liquid fuel combustion apparatus of the sixth aspect, it becomes possible to suppress the maximum temperature and the average temperature of the primary combustion flame to be low, so that not only the amount of NOx produced can be reduced but also the secondary combustion flame can be reduced. Since the flame hole portion has a plurality of secondary flame holes radially formed, the secondary combustion flame formed in the secondary flame hole portion is prevented from being offset, and the secondary combustion flame and the secondary combustion flame are prevented. The contact with the secondary air can be made uniform and the reburning effect is improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a liquid fuel combustion apparatus showing an embodiment of the present invention.

FIG. 2 is likewise an enlarged cross-sectional view of a main part.

FIG. 3 is a plan view of the primary combustion cylinder with a flame spreading resistance plate removed.

FIG. 4 is a characteristic diagram showing the relationship between the height H from the secondary air hole to the tip of the primary combustion cylinder and the amount of NOx produced.

FIG. 5 is a sectional view of a conventional liquid fuel combustion device.

[Explanation of symbols]

 30 Vaporizing Tube 37 Burner Plate (Primary Flame Hole) 40 Secondary Air Hole (Secondary Air Supply Section) 42 Primary Combustion Tube (Cylinder) 44 Secondary Flame Hole 45 Secondary Flame Hole 46 Flame Spreading Resistance Plate

Claims (6)

[Claims] 1. A vaporization cylinder for vaporizing a liquid fuel and mixing the vaporized gas with primary air; a primary flame hole portion provided on the vaporization cylinder for ejecting and burning the mixed gas in the vaporization cylinder;
A cylinder connected to the vaporization cylinder so as to cover the primary flame hole, a secondary flame hole provided at the tip of the cylinder, and a secondary air supplying secondary air to the outer circumference of the cylinder. A liquid fuel combustion apparatus comprising: a supply unit. 2. A vaporization cylinder for vaporizing liquid fuel and mixing the vaporized gas with primary air; a primary flame hole portion provided in the vaporization cylinder for ejecting and burning the mixed gas in the vaporization cylinder;
A cylinder connected to the vaporization cylinder so as to cover the primary flame hole, a secondary flame hole provided at the tip of the cylinder, and a secondary air supplying secondary air to the outer circumference of the cylinder. A liquid fuel combustion apparatus comprising: a supply unit; and a flame spreading resistance plate provided to face the secondary flame hole portion. 3. A vaporization cylinder for vaporizing a liquid fuel and mixing the vaporized gas with primary air; a primary flame hole portion provided in the vaporization cylinder for ejecting and burning the mixed gas in the vaporization cylinder;
A cylinder connected to the vaporization cylinder so as to cover the primary flame hole, a secondary flame hole provided at the tip of the cylinder, and a secondary air supplying secondary air to the outer circumference of the cylinder. Liquid fuel combustion characterized by comprising a supply part and a flame spreading resistance plate provided so as to face the secondary flame hole part, and the flame spreading resistance plate is approximately the same size as or slightly larger than the cylindrical body. apparatus. 4. A vaporization cylinder for vaporizing a liquid fuel and mixing the vaporized gas with primary air; a primary flame hole portion provided in the vaporization cylinder for ejecting and burning the mixed gas in the vaporization cylinder;
A cylinder connected to the vaporization cylinder so as to cover the primary flame hole, a secondary flame hole provided at the tip of the cylinder, and a secondary air supplying secondary air to the outer circumference of the cylinder. And a supply section,
A liquid fuel combustion apparatus characterized in that the cylinder is attached in close contact with a vaporization cylinder. 5. A vaporization cylinder for vaporizing a liquid fuel and mixing the vaporized gas with primary air; a primary flame hole portion provided in the vaporization cylinder for ejecting and burning the mixed gas in the vaporization cylinder;
A cylinder connected to the vaporization cylinder so as to cover the primary flame hole, a secondary flame hole provided at the tip of the cylinder, and a secondary air supplying secondary air to the outer circumference of the cylinder. And a supply section,
A liquid fuel combustion apparatus, wherein the cylindrical body is made of a heat-resistant metal material having excellent heat absorption. 6. A vaporization cylinder for vaporizing a liquid fuel and mixing the vaporized gas with primary air; a primary flame hole portion provided in the vaporization cylinder for ejecting and burning the mixed gas in the vaporization cylinder;
A cylinder connected to the vaporization cylinder so as to cover the primary flame hole, a secondary flame hole provided at the tip of the cylinder, and a secondary air supplying secondary air to the outer circumference of the cylinder. And a supply section,
The liquid fuel combustion apparatus, wherein the secondary flame hole portion has a plurality of secondary flame holes radially formed.