JP2000291910A - Liquid fuel combustion equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent combustion faults due to an air excess or insufficiency of an inner surface of a combustion cylinder by providing a flame stabilizing ring perpendicular to the axis of the cylinder near a position, where an outer periphery of a conical spray nozzle arrives at the inner surface of the cylinder in a liquid fuel combustion equipment having the cylinder of a circular sectional shape forward of the nozzle. SOLUTION: In this liquid fuel combustion equipment for an oil water heater, fuel (kerosene) from a solenoid pump is supplied to a spray nozzle 101 through a fuel supply passage 102, and sprayed into a conical shape from the nozzle 101. Combustion air from a fan is supplied to a main air port 201 opened at an outer cylinder 207, partly given by a circumferential speed by many contracted louvers provided on a periphery of a turn chamber 211, and detoured out of a fuel spray pattern. In this case, a flame stabilizing ring 405, brought at its outer periphery into contact with an inner surface of a first combustion cylinder 401, is provided near a boundary between first and second combustion cylinders 401 and 402 where fuel particles disposed on a conical periphery sprayed from the nozzle 101 reach, and a combustion fault due to air excess or insufficiency is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray nozzle for spraying a liquid fuel forward in a conical shape, a combustion cylinder located in front of the spray nozzle and having a circular cross-sectional shape coaxial with the spray nozzle. Air from the rear of the combustion cylinder to the front or
The present invention relates to a liquid fuel combustion device that supplies from the outer periphery toward the center.

[0002]

2. Description of the Related Art Generally, liquid fuel particles sprayed from a spray nozzle fly out linearly along a conical outer periphery having a predetermined apex angle. Combustion devices often supply combustion air to the spray from the back or perimeter, and the liquid fuel particles are swept into this air stream, causing the spray pattern to tend to be narrower than the initial cone. . The influence of the air current is stronger for small-sized particles having a small mass, and conversely, large-sized particles having a size of 70 μm or more are hardly affected. Therefore, the particles fly linearly while maintaining the initial velocity of spraying. As a result, in the conical spray, large-diameter particles are distributed on the outer periphery and small-diameter particles are distributed inside.

[0003] Further, small-diameter particles have a large surface area with respect to their volume, so they are quickly evaporated and burned in a high-temperature atmosphere inside the combustion tube, while large-diameter particles take time to evaporate. As described above, the large-diameter particles have a high velocity and are present on the outer periphery of the spray, and it takes time to evaporate. Therefore, the particles reach the inner surface of the combustion cylinder without evaporating. Since the inner surface of the combustion cylinder is heated by the internal flame, it is maintained at a temperature equal to or higher than the boiling point of the liquid fuel, and the fuel particles in contact there evaporate quickly, or are rapidly broken after being crushed by collision and atomized. Evaporates and burns.

[0004] If the air used for combustion on the inner surface of the combustion cylinder is insufficient, the combustion on the inner surface of the combustion cylinder becomes a bright flame, soot adheres to the inner surface of the combustion cylinder, and causes soot scattering. Also, if the air used for combustion on the inner surface of the combustion cylinder is excessive, the flame temperature on the inner surface of the combustion cylinder decreases and the flame is extinguished.
It is exhausted in an unburned state, causing odor. The occurrence of defective combustion inside the combustion cylinder due to excess or insufficient air inside the combustion cylinder is one factor that limits the combustion range of the liquid fuel combustion device.

In particular, in a proportional combustion type liquid fuel combustion apparatus in which the fuel supply amount and the combustion air amount are made variable in accordance with the calorie requirement, the combustion is properly performed with the same air amount distribution from the minimum combustion to the maximum combustion. Is difficult, for example, as disclosed in Japanese Patent Application Laid-Open No. 8-178255, a structure is used in which a two-stage damper is used to control the amount of air and its distribution.

[0006]

According to the structure in which the distribution of the amount of air is also controlled by the damper, appropriate distribution can be performed according to the amount of combustion. The combustion range of the liquid fuel combustion device is still limited by the occurrence of defective internal combustion, and high component dimensional accuracy and accurate oil amount adjustment are required so that excess or deficiency of air does not occur.

According to the present invention, there is provided a spray nozzle for spraying a liquid fuel forward in a conical shape, a combustion cylinder positioned in front of the spray nozzle and having a circular cross-sectional shape coaxial with the spray nozzle, and burning the combustion air with the combustion air. In a liquid fuel combustion device that feeds from the rear to the front of the cylinder or from the outer circumference to the center, it prevents the occurrence of poor combustion inside the combustion cylinder due to excess or insufficient air inside the combustion cylinder, and prevents variations in air and oil amount adjustments. To obtain a wide combustion range.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, in the liquid fuel combustion apparatus, a position of an outer peripheral portion of a conical spray reaching an inner surface of a combustion cylinder is defined. In the vicinity, a flame holding ring having a surface substantially perpendicular to the axis of the combustion cylinder, projecting inside the combustion cylinder, and having an outer periphery in contact with the inner surface of the combustion cylinder was provided. As described above, large-diameter particles in the liquid fuel spray have a high velocity and are present on the outer periphery of the spray, and it takes a long time to evaporate. The fuel particles in contact with the flame ring evaporate quickly or are crushed by collision to become fine particles that are easily evaporated.

On the other hand, the combustion air flows in the axial direction as a whole, and the flame holding ring has a surface substantially perpendicular thereto. Since the air flow is a continuous fluid, it passes through the inside from a little before it without hitting the vertical plane, avoiding the flame ring. As a result, the upstream side of the flame holding ring becomes a stagnant place with no air flow, where fuel vapor and fine particles that evaporate easily are generated. Can maintain a sufficient concentration, and can prevent generation of an odor due to flame extinction due to a decrease in flame temperature.

In claim 2, air is supplied along the inner surface of the combustion cylinder from downstream of the flame holding ring in addition to the flame holding ring. The fuel vapor generated on the upstream side of the flame holding ring and the fine particles that easily evaporate form a flame held in the recirculation zone existing on the downstream side of the flame holding ring, but are supplied from upstream. If the air used for combustion is insufficient, the flame becomes a bright flame.
This bright flame is blocked by the air supplied along the inner surface of the combustion cylinder and does not touch the inner surface of the combustion cylinder, so that no soot adheres to the inner surface of the combustion cylinder.

In the third aspect, the inside of the flame holding ring is bent forward. The fuel vapor generated on the surface on the upstream side of the flame holding ring and the fine particles that easily evaporate form a flame held in the recirculation zone existing on the surface on the downstream side of the flame holding ring. Since the flame is bent forward, this flame is formed at a position corresponding to the bent length away from the surface on the downstream side of the flame stabilizer ring, and soot adheres to the surface on the downstream side of the flame stabilizer ring. There is no.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a main assembly of a liquid fuel combustion apparatus for an oil water heater according to a preferred embodiment of the present invention. Kerosene as fuel is pressurized by an electromagnetic pump (not shown), supplied to the spray nozzle 101 through the fuel supply path 102, and sprayed. This spray pattern is a hollow cone having a conical outer periphery with a vertex angle of about 80 degrees. By disposing the spray nozzle at a position where the outer periphery of the spray does not touch the primary air port 216, the spray
6 to prevent dripping. for that reason,
The spray pattern is distributed inside the primary air port. Excess fuel not used for combustion is supplied to the fuel return path 1
, And is returned to the electromagnetic pump via a flow control valve (not shown). Adjustment of the fuel supply amount to burn
The adjustment is performed based on the amount passing through the flow control valve.

The combustion air supplied from a fan (not shown) is supplied from a main air port 201 opened in an outer cylinder 207. A part of the combustion air is given a flow velocity in the circumferential direction by a large number of throttle cutouts 217 provided on the outer periphery of the large-diameter swirling chamber 211, and flows into the smaller-diameter primary air cylinder 215. The number and size of the squeeze cuts 217 are determined so that the swirl number at the primary air port 216 is 2.0. When the swirling air flows from the large-diameter swirling chamber 211 into the small-diameter primary air cylinder 215, the angular momentum is preserved, so that the diameter is reduced, so that the circumferential flow velocity is accelerated. The primary air port 216 has a smaller diameter than the primary air cylinder 215 and is narrowed down in an orifice shape. The swirled primary air has a main flow due to the centrifugal force at the outer peripheral portion of the primary air cylinder. Therefore, if there is no orifice-shaped throttle, the main flow immediately exits the primary air port 216 due to the centrifugal force. As the air spreads and wraps around the spray pattern distributed inside the primary air port, there is a shortage of air near the center and the flame extends. The primary air port 216 is connected to the primary air cylinder 2
By squeezing the orifice into a smaller diameter than that of the primary air outlet 15, the main air of the primary air flowing out of the primary air outlet 216 spreads after being slightly reduced inward, and thus is distributed inside the primary air outlet. Since it substantially matches the spray pattern and approaches a homogeneous mixture, the combustibility is improved and the NOx emission concentration is also reduced.

The spray nozzle 101 located in the swirling chamber 211 is covered with a cylindrical nozzle cap 213. A plurality of small-diameter nozzle cap side holes 214 are formed at the base of the nozzle cap 213, and the air flowing from these holes is rectified, so that the air flowing through the gap between the spray nozzle 101 and the nozzle cap 213 is swirled. Can be stopped. The non-swirl air flowing out from the tip of the nozzle cap 213 blows back soot carried on a recirculating flow described later, thereby preventing soot from adhering to the nozzle surface. In addition, the non-swirl air flowing out from the tip of the nozzle cap 213 travels straight along the center line without spreading, and becomes the axis of the entire swirl flow, stopping the precession of the swirl flow. It also has the effect of preventing generation and reducing noise. Nozzle cap 2
Since the inner diameter of 13 is larger than the outer diameter of the box wrench for tightening the spray nozzle 101, it does not prevent the spray nozzle 101 from being removed from the front of the combustion device.

A part of the combustion air supplied from the main air port 201 passes through a partition plate hole 226 of a partition plate 203 provided with a gap from the first combustion cylinder 401. Since there is a gap between the partition plate 203 and the first combustion cylinder 401,
The combustion air supplied from the main air port 201 is not directly blown onto the first combustion cylinder 401 to be supercooled.

A portion of the combustion air passing through the partition plate hole 226 passes through the gap between the first combustion cylinder 401 and the partition plate 203 and is swirled and swirled to provide secondary air in the same direction as the primary air. 221 and merges with the swirling flow of the primary air. Part of the entrance of the swirling secondary air hole 221 is closed by the partition plate 203 so that the swirling secondary air does not become excessive.

The primary combustion flame is formed by the swirling air flow and the fuel vapor from the spray. The unburned air and the fuel vapor flow around the outer periphery of the first combustion cylinder 401 by centrifugal force due to the low temperature and high density. Since the combustion air generated by the combustion has a high temperature and a relatively low density, it gathers at the center of the first combustion cylinder 401, and a part of the combustion air is spray nozzle 1
A recycle stream is formed towards 01. By this high-temperature recirculation flow, the spray from the spray nozzle 101 is heated and evaporated to supply fuel vapor to the primary combustion flame, thereby forming a stable primary combustion zone with a high combustion load.

A part of the combustion air passing through the partition plate hole 226 is passed through a gap between the first combustion tube 401 and the partition plate 203 and a small number of auxiliary air holes 22 opened in the first combustion tube 401.
Spout from 2 towards the center. The auxiliary air ejected from the auxiliary air hole 222 breaks through the swirling flow and
It reaches the center of 01. If the primary combustion region is only the swirling flow, the combustion air is collected at the outer peripheral portion by centrifugal force, and the air in the central portion may be insufficient, and smoke may be generated. In addition, this auxiliary air flow divides the swirling cluster of the primary combustion flame into spirals and subdivides it, increasing the frequency of generation and disappearance of clusters.
The frequency of the burning roar has been raised. The high frequency combustion roar can be easily silenced by a silencer provided in an exhaust path (not shown).

A part of the combustion air passing through the partition plate hole 226 is supplied to the secondary air hole 223 opened in the second combustion cylinder 402.
To the center, and the secondary air through hole 40 opened substantially coaxially with the secondary air hole 223 in the first combustion cylinder 401.
8 and is jetted into the combustion cylinders 401 and 402. In the secondary air passage, there is a flame holding ring bending portion 406, but a cutout 409 is provided so as not to hinder the flow of the secondary air. The secondary air blown out toward the center is supplied to the secondary combustion area downstream as combustion air,
An upstream inward flow is provided at the upstream end of the primary combustion zone to assist in the stable formation of the aforementioned recycle stream.

A part of the combustion air passing through the partition plate hole 226 is supplied to the wall air supply hole 2 formed in the second combustion cylinder 402.
24, the air is supplied to the wall air chamber 403 sandwiched between the first combustion cylinder 401 and the second combustion cylinder 402,
Air outlet 40 which is a gap between
4 flows out forward along the wall surface of the second combustion cylinder 402. This wall air discharge port 404 is located ahead of the flame holding ring 405.

Part of the air passing through the partition hole 226 is
The second combustion cylinder 402 escapes into the second combustion cylinder 402 from the rear air vent hole 225 opened near the tip. Since the second combustion cylinder 402 is cooled from the back by this airflow,
The material will not be overheated beyond its heat resistant temperature.

The large fuel particles located on the outer periphery of the conical shape sprayed from the spray nozzle 101 are supplied to the first combustion cylinder 401.
And the vicinity of the boundary between the second combustion cylinder 402 and the second combustion cylinder 402, the surface has a surface substantially perpendicular to the axis of the combustion cylinder 401, 402, protrudes inside the combustion cylinder 401, 402, and the outer periphery is the first combustion cylinder 401. Is provided with a flame holding ring 405 in contact with the inner surface of the frame. The flame holding ring 405 overlaps the first combustion cylinder 401 and the second combustion cylinder 402 three times and is fixed by spot welding. Depending on the combustion conditions, this flame holding ring may reach a high temperature of 1000 ° C. or more, so an ultra-low carbon ferritic steel containing 20% chromium is used. Ferritic steel has low strength at high temperatures, but does not transform even after repeated heating and cooling.
Thermal deformation can be prevented. By adding 5% of aluminum to the material component, the chromium oxide layer formed on the surface is densified by aluminum oxide. A similar effect can be obtained by adding silicon.However, since silicon oxide is reduced by OH groups caused by high-temperature steam in the combustion gas and may lose its effect, aluminum should be used for the combustion device. good. Further, a small amount of lanthanum is added to the material components to prevent the chromium oxide layer formed on the surface from peeling off. Other rare earth metals such as yttrium and scandium may be added to obtain the same effect. The addition of aluminum to the component reduces the strength of the material, but a small amount of zirconium is added to the material component to refine the metal crystal, thereby increasing elongation and preventing breakage due to drawing. The same effect can be obtained by adding titanium or niobium, but titanium and niobium are carbonized by carbon monoxide in the high-temperature combustion gas, and abnormal corrosion may occur. Is good.

In the liquid fuel spray sprayed from the spray nozzle 101, large-diameter particles have a high speed, exist on the outer periphery of the spray, and take a long time to evaporate.
It reaches the surface on the upstream side of 05. Flame holding ring 405 is combustion cylinder 4
01, 402, the fuel particles are heated to a temperature equal to or higher than the boiling point of kerosene, and the fuel particles in contact with the flame holding ring 405 evaporate quickly, or are crushed by collision to easily evaporate. Becomes

On the other hand, the combustion air flowing while circling along the wall surface of the first combustion tube 401 is
The vehicle passes through the inside so as to avoid the flame holding ring 405 slightly shortly before colliding with the substantially vertical surface at 05. As a result, the upstream surface of the flame holding ring 405 becomes a stagnant place where there is no flow of air, where fuel vapor and fine particles that easily evaporate are generated. The fuel can maintain a sufficient concentration, and it is possible to prevent the generation of odor due to the decrease in the flame temperature and the extinction of the flame.

The fuel vapor generated on the upstream surface of the flame holding ring 405 and the easily vaporized fine particles form a flame held in the recirculation zone existing on the downstream surface of the flame holding ring 405. If the air supplied from the upstream for combustion is insufficient, the flame becomes a bright flame. This bright flame is blocked by air supplied from the wall air discharge port 404 forward along the wall surface of the second combustion cylinder 402 and does not touch the inner surface of the combustion cylinder, so that soot adheres to the inner surface of the combustion cylinder. Never. Further, the surface of the second combustion cylinder 402 is protected from heat by air supplied along the wall surface of the second combustion cylinder 402, and is not overheated beyond the heat resistant temperature of the material. If the air used for combustion supplied from the upstream runs short, the wall air discharge port 4 is used to burn the fuel vapor generated on the upstream surface of the flame holding ring 405 and the fine particles that are easily evaporated.
Since the air supplied from 04 along the wall surface of the second combustion cylinder 402 is used, there is no shortage of air.

Inside the flame holding ring 405, a bent portion 406 bent forward is provided. The aforementioned flame ring 40
(5) The fuel vapor generated on the upstream surface and the fine particles that easily evaporate form a flame held in the recirculation zone present on the downstream surface of the flame holding ring 405. The flame is formed at a position away from the surface on the downstream side of the flame holding ring by the length corresponding to the bending length, soot adheres to the surface on the downstream side of the flame holding ring, or the flame holding ring is overheated to reduce the heat resistant temperature. No more.

The air cone 40 abutting on the tip of the second combustion cylinder 402 and protruding inward from the inner surface of the second combustion cylinder 402
7 are provided. Of the air supplied along the wall surface of the second combustion cylinder 402, a portion not used for combustion is sent to the inside of the combustion cylinder by the air cone 407, and contributes to shortening the flame.

Although the upstream diameter of the first combustion cylinder 401 is set to a size suitable for stabilizing the flame, the heat exchanger to be heated is larger than this, so that the combustion cylinders 401, 401 can be uniformly heated. Reference numeral 402 designates a frustoconical shape with a widening cone. Since the combustion air flow is swirling, an outward centrifugal force is applied. Even when the combustion air flow spreads, the flow does not separate from the wall surface and collect at the center. Combustion cylinders 401, 402
Is fixed only at its tip, and the first combustion cylinder 4
01 and the primary air cylinder 215, and the partition plate 203 and the outer cylinder 207 are inserted with a gap therebetween. During combustion, the combustion cylinders 401 and 402 are heated by the flame therein and thermally expand. However, since they are fixed only at the tip, the other ends can move freely and no thermal stress is generated.
Thermal deformation and thermal stress cracking can be prevented. The gap between the first combustion cylinder 401 and the primary air cylinder 215 is unbalanced, and if air flows into the combustion cylinder from this gap, it may cause the flame to be unbalanced.
A packing 208 made of rock wool for holding air from the gap is provided.

The tertiary air supplied from a fan (not shown) is supplied to a tertiary air chamber 231 through a tertiary air port 202. The air supplied to the tertiary air chamber 231 flows outward from a tertiary air supply port 234 opened on a side wall formed by drawing on a burner flange 233 attached to the tertiary air chamber 231 by caulking, and heat exchange occurs. Tertiary air supply port 23 of side wall formed by bending container flange 502
The air is blown onto the heat exchanger inner body 501 made of a copper plate through the tertiary air discharge port 235 opened at a position facing 4.
The tertiary air blown to the heat exchanger inner body 501 spreads on the inner surface of the heat exchanger inner body 501 without participating in combustion, and forms an air layer. Since the inner surface of the heat exchanger inner body 501 does not come into direct contact with the combustion air due to this air layer, the temperature rise, thermal stress, soot adhesion, dew condensation water generation, and corrosion due to dew water of the heat exchanger inner body 501 can be prevented, Unburned air during combustion is not quenched.
It also has the effect of preventing the generation of carbon monoxide.

Since the tertiary air discharge port 235 on the downstream side is smaller than the tertiary air supply port 234 on the upstream side, the burner flange 233 and the heat exchanger flange 502 are located between them.
There is no internal pressure in the gap, and no combustion air enters. Therefore, even if the gasket for preventing external leakage between the burner flange 233 and the heat exchanger flange 502 leaks, the leaked gas is not high-temperature combustion gas but only tertiary air near normal temperature, which is safe.

The copper plate heat exchanger flange 502 is brazed to the heat exchanger inner body 501. During brazing, the heat exchanger flange 502 made of copper plate is annealed, and its strength is reduced. The flange may be deformed and the thread may be licked. Prevents coarse graining. The burner flange 233 is screwed to the heat exchanger flange 502. The tip of the burring 236 raised from the burner flange 233 is applied around the female screw of the heat exchanger flange 502. The surrounding area is not deformed and the threads are not easily licked. Heat exchanger flange 502 and heat exchanger inner body 50
In addition to 1, the components of the heat exchanger such as fins and fin pipes (not shown) are all made of copper, so that impurities such as iron do not mix into the recycled material even if they are not decomposed when recycled as a material.

The burner flange 233 and the heat exchanger flange 502 both have a substantially square shape. For this reason, it is also possible to change the direction of each other and attach them.
Even if you change the mounting direction, you can use the same parts
Extra holes or stays for screwing may be provided on any of the flanges.

The combustion device is ignited by applying a high voltage periodically generated by an ignition transformer (not shown) to the electrode rod 610 and sparking by discharge. The tip of the electrode rod 610 is located behind the conical outer circumference of the spray so that the fuel spray does not hit the electrode rod during fuel combustion and kerosene does not drip. Thus, the first discharge occurs outside the spray pattern. After the discharge spark passes, a row of ions generated by the spark remains, and current easily flows along the ion row. Since the electrode rod 610 is in the airflow of primary air, at the next moment, the ion train is swept by the airflow and located downstream of the tip of the electrode rod 610. Since the next discharge is performed along the ion train that has flowed into the airflow, the electrode rod 61
A spark is generated downstream of the leading end of zero. In this way, the discharge spark enters the spray pattern while being swept by the airflow, where the fuel is evaporated and ignited by the effect of discharge energy and ionization. Although the protrusion is reduced so that the insulator 611 of the electrode rod 610 does not obstruct the flow of air in the swirl chamber, the insulator is provided with a depression so as to increase the creepage distance so that the spark does not leak to other parts. I have. The electrode rod 610 is routed near the center of the swirling chamber so as not to obstruct the flow of air in the swirling chamber.

The ignition is confirmed by detecting the emission of the flame by the flame detector 62.
This is performed by detecting at 0. In the flame detector 620,
A photo IC diode in which a silicon photodiode and a current amplifier circuit are formed on one chip is used. Since the photo IC diode has a built-in current amplifier circuit, the photo IC diode is resistant to external noise, and can correctly detect a flame even when discharging from the electrode bar 610. In addition, since there is little difference between individuals and high linearity as compared with a phototransistor or a photoconductive element, a diagnosis of a combustion state can be made based on the current value. The protrusion is reduced so that the flame detector 620 does not obstruct the flow of air in the swirl chamber.

FIG. 2 shows the main air port 201 and the tertiary air port 20.
FIG. 3 is a cross-sectional view of a main part of a duct that supplies air to the air conditioner 2. The main air duct 241 communicates with the main air port 201 downstream thereof,
The tertiary air duct 242 leads downstream to the tertiary air port. The upstream of the main air duct 241 and the tertiary air duct 242 communicates with the outlet of a common fan (not shown). The main air duct 241 and the tertiary air duct 242 are provided in parallel with each other, and one damper shaft 245 penetrates both. A main damper 243 smaller than the cross section of the main air duct 241 is provided on the damper shaft 245 in the main air duct 241.
At 45, tertiary dampers 244 smaller than the cross section of the tertiary air duct 242 are screwed at 90 degrees to each other. When the amount of combustion is large, the amount of air used for combustion is large. Therefore, when the main damper 243 is set to the fully open position parallel to the main air duct 241, the tertiary damper 244 automatically corresponds to a gap with the tertiary air duct 242. The opening degree becomes the minimum, and the combustion air can be effectively sent to the main air port 201. When the combustion amount is the minimum, the main damper 24
3 is set to the minimum opening corresponding to the gap with the main air duct 241, the tertiary damper 244 automatically turns the tertiary air duct 2
It becomes a fully open position parallel to 42.

This damper acts to increase the amount of tertiary air that does not contribute to combustion at the time of minimum combustion, so that the overall air ratio can be increased, and condensation in the heat exchanger can be prevented. Further, since the total amount of air does not greatly decrease compared to the maximum combustion, the differential pressure of the main damper 243 does not increase so much, and even if the minimum opening degree of the main damper 243 slightly varies, the variation of the combustion air should be reduced. Can be. Furthermore, since there is no significant deviation from the design point of the fan, the occurrence of surging can be prevented.

In the above embodiment, the liquid fuel combustion device used for the oil hot water heater has been described. However, the present invention is not limited to this, and is used for a liquid fuel combustion device for heating a furnace and a combustion can of a gas turbine. A liquid fuel combustion device that burns on the same principle, such as a liquid fuel combustion device and a liquid fuel combustion device for heating a boiler, can also be used.
In addition, kerosene was used as an example of fuel, but the fuel is not limited to this, and any fuel that can be sprayed as liquid, such as volatile oil, light oil, crude oil, heavy oil, methanol, ethanol, methane hydrate, dimethyl ether, etc. It can be used for various fuels. Furthermore, although the pressure spray was taken as an example of the spray method, the present invention is not limited to this.
It goes without saying that any method such as liquid column spraying, liquid film spraying, and internal mixing method may be used.

[Brief description of the drawings]

FIG. 1 is a sectional view of an assembly of a main body of a liquid fuel combustion device for an oil hot water heater according to a preferred embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a duct for supplying air.

[Explanation of symbols]

 101: spray nozzle 401, 402: combustion cylinder 404: wall air discharge port 405: flame holding ring 406: bent part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Zenji Fujiwara 43-1, Uozakihama-cho, Higashinada-ku, Kobe, Hyogo Prefecture Within Nihon Yupro Corporation (72) Inventor Shinya Ohira 43-1, Uozakihama-cho, Higashinada-ku, Kobe, Hyogo No. Japan Yupro Co., Ltd. (72) Inventor Koji Koseki 43-1, Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo Japan F-term (reference) 3K055 AA07 AA10 AB04 AB08 BA01 BA11 BB10 BC02 BC06 BC10 BD04

Claims (3)

[Claims] 1. A spray nozzle for spraying a liquid fuel forward in a conical shape, a combustion cylinder located in front of the spray nozzle and having a circular cross section coaxial with the spray nozzle, and a combustion air flowing through the combustion cylinder. In the liquid fuel combustion device supplying from the rear to the front or from the outer periphery toward the center, near the position where the outer peripheral portion of the conical spray reaches the inner surface of the combustion cylinder, substantially perpendicular to the axis of the combustion cylinder. A liquid fuel combustion device, comprising: a flame holding ring having a surface, protruding inside the combustion cylinder, and having an outer periphery in contact with an inner surface of the combustion cylinder. 2. The liquid fuel combustion apparatus according to claim 1, further comprising a wall air discharge port for supplying air from the downstream side of the flame holding ring along the inner surface of the combustion cylinder. 3. Inside the flame holding ring, toward the front,
3. The liquid fuel combustion device according to claim 1, wherein the liquid fuel combustion device has a bent portion.