JPS60223907A - Combustion method of liquid fuel evaporation type burner - Google Patents

Abstract

PURPOSE:To drop an excess air ratio close to a theoretical mixture ratio by fulfilling complete blue flame combustion, by separating completely a circulating region of high- temperature combustion gas from a nozzle region, a combustion air flow region, a layer of an evaporation region, a mixing region and a combustion region. CONSTITUTION:A burner cone 6 made of porous ceramics is provided coaxially with a nozzle 3, a current forming plate 8 made of the porous ceramics is arranged on an outlet part of the burner cone 6 coaxially with the burner cone 6 by facing a protruded surface of the current forming plate 8 toward the inside of the burner cone and a flame holding ring 9 is provided coaxially with the current forming plate in front of the current forming plate. As separation of a circulating region (f) of high-temperature combustion gas from a nozzle region (a), a combustion air flow region (b), a fuel evaporation region (c), a mixing region (d) and a combustion region (e) is performed completely and an oil drop sprayed through a nozzle of the nozzle region (a) is gasified through thermal evaporation by high-temperature combustion gas sucked through the circulating region (f), which is mixed with air in the mixing region (d) after that and then made to ignite stably in the combustion region (e).

Description

[Detailed description of the invention] The present invention relates to a combustion method for a liquid fuel vaporizing burner.

The combustion of kerosene is broadly divided into two types, gastritis and zero flame, depending on its mode. A premixed flame containing sufficient oxygen causes gastritis, and a diffusion flame causes zero flame (luminous flame). It is estimated that the combustion process is similar to the flowchart shown in FIG.

As can be seen from the graph of FIG. 4, the difference between the two combustions is caused by the way oxygen diffuses. The following factors affect this oxygen diffusion.

■M Air stone for burning (i.e. oxygen amount) ■Mass of fuel 6h Yu Handle nl h In order to perform gastritis combustion, either the amount of air for combustion is large enough or the mass of fuel is small (i.e. in the case of atomized fuel) Either the atomization is good and the size of the oil droplets is small), or the flow is highly turbulent and the fuel and oxygen need to be mixed sufficiently.

However, in the case of combustion using a gun-type burner, which is often used for general kerosene combustion, it is difficult to cause gastritis combustion even if the above conditions are met. This is because in general gun-type burners, a flame holder is installed immediately after the atomized fuel nozzle, and a stable flame is formed in this part, which becomes the ignition source for the subsequent fuel, as shown in Figure 3. Each stage of combustion proceeds simultaneously, and the sprayed oil droplets are ignited around the oil droplets before being thermally decomposed into a complete gaseous body with a light mass, and are surrounded by concentric diffusion flames and combust. do.

For this reason, the diffusion of oxygen is insufficient, and internal flame combustion occurs instead of blue flame.

In internal flame combustion (diffusion combustion), the diffusion of oxygen is through the flame of the diffusion flame method to the above layer on the surface of the internal oil droplets, and the mixing of fuel and air is due to the fact that the fuel is in the form of oil droplets. Due to its large mass, it must be promoted by large turbulence in the flow or by excessive air volume. For this reason, internal flame combustion burners require measures to generate large turbulence in the flow (eg, generation of maximum impulsive flow) and also require the supply of an excessive amount of air.

In internal flame combustion, an oxidation reaction of colloidal carbon occurs, but if oxygen diffusion is insufficient at this time, this colloidal carbon is discharged as soot. Such insufficient diffusion of oxygen may occur due to local mixing defects even if the amount of oxygen is sufficient.

Insufficient oxygen diffusion also results in the emission of oxidized intermediates (often -carbon oxides).

The increase in the content of the above two combustion emissions becomes noticeable when the excess air ratio is lowered, and for this reason, it has been difficult to reduce the excess air ratio below a certain level in diffusion combustion.

In internal flame combustion, it is necessary to generate large turbulence in the flow to promote mixing, but since this is turbulence in the flow including the diffusion flame method during combustion, the noise is loud and was the main cause of combustion noise. Another disadvantage is that the more turbulent the flow is to achieve complete combustion, the louder the noise becomes. Additionally, to prevent such turbulence from occurring, it is common practice to narrow down the flow path at the rear of the flame holder, but in this case the flame is formed in a narrow space with some openings. So the sound gets louder.

On the other hand, in gastritis combustion, oxygen is diffused through vaporized gaseous fuel, so it is easily diffused, and there is little need for large turbulence in the flow or excessive amount of air.

Therefore, in gastritis combustion, it is possible to reduce the excess air ratio to almost the stoichiometric ratio.

In blue flame, the proportion of colloidal carbon produced is small;
In addition, since the gaseous fuel and oxygen are well diffused and mixed, even if the excess air ratio is lowered, soot and carbon oxide emissions are small, and it is possible to perform combustion close to complete combustion.

In this way, by lowering the excess air ratio, combustion is possible close to the theoretical combustion air amount, and because the mixing is good, the combustion area is narrowed, so the flame temperature becomes close to the adiabatic flame temperature, which increases the temperature. Become.

Gastritis combustion is quieter because it burns after mixing is complete, and is quieter because it forms a flame at the open end.

As described above, gastritis combustion is clearly superior to internal flame combustion as a combustion method for liquid fuel vaporization burners.

Therefore, the object of the present invention is how to achieve complete blue flame combustion in a liquid fuel vaporization burner, particularly in a burner with an output range of 23,000 to 57,000 Kcal.

In order to achieve complete gastritis combustion, in addition to oxygen diffusion (that is, mixing), it is necessary to separate the nozzle region, combustion air region, fuel vaporization region, mixing region, combustion region, and hot combustion gas circulation region.

The present invention has a nozzle area (a), a combustion air flow 1, and
1(b), by completely separating the fuel vaporization zone (C), mixing zone (d), combustion zone (e), and high-temperature combustion gas circulation zone Cf), the oil sprayed from the nozzle in the nozzle zone is The droplets are first converted into a gaseous state by thermal vaporization by the hot combustion gas drawn through the circulation area without being ignited in the form of oil droplets in the fuel vaporization zone, and then the fuel becomes gaseous in the mixing zone. The mixture is mixed with air and then stably ignited in the combustion zone.

In order to separate the nozzle area, combustion air area, fuel vaporization area, mixing area and combustion area, and high temperature combustion gas IK ring area,
There should be no mixing and flame formation in the fuel vaporization zone, and there should be no flame formation in the mixing zone.

Technique 1 taken by the present invention in order to achieve the above object: The technique is to surround a fuel spray nozzle that is held in a nozzle holder and is provided facing into the combustion chamber, and to install an air outlet coaxially with the nozzle. The design number is a nozzle area, and a combustion gas suction port is provided in front of this air outlet between the air outlet and the straight cylindrical part and the front end of the cylindrical part continues to expand forward. Formed into a cylindrical shape consisting of an opening with a porosity of 20~
A burner cone made of 50% porous ceramic is installed coaxially with the nozzle surrounding the fuel spray area of the nozzle, and a hollow cone made of porous ceramic similar to the burner cone with an open bottom is installed at the outlet of the burner cone. A rectifying plate formed into a shape or semi-spherical shape with small holes perforated on its circumferential surface is arranged coaxially with the convex side facing inside the burner cone, and a roughly ■-shaped or U-shaped rectifying plate is placed in front of the rectifying plate. A flame stabilizing ring formed in an annular shape having a cross-sectional shape is provided coaxially with the current plate, and the dimensional relationship between these parts is set to
al/H burner, the nozzle has a spray angle of 60
The pattern is Hollow Cone at °, the outside diameter of the nozzle holder is φ21, the air blowing speed from the air blowing port is 19IIl/S to 101+/s, the air blowing area is 0.00077m to 0.001
46i The inner diameter of the air outlet is φ37 to φ48. The ratio of the inner diameter of the burner cone cylindrical part and the inner diameter of the air outlet is 1,
3 or more Air outlet inner diameter to length ratio 172 or more Air outlet length 20H1 or more Air outlet cross-sectional area/(Cross-sectional area of burner cone cylindrical part - Cross-sectional area of air outlet) <1 Cross-sectional area of burner cone cylindrical part The difference between the cross-sectional area of the burner cone cylindrical part and the cross-sectional area of the air outlet is 0.00077 in' or more.The inner diameter of the burner cone cylindrical part is φ48 or more. 0.00154 to 0.0
The expansion angle of the 066 fiber cone expansion part is 30 degrees, the amount of oil injected from the nozzle is 2.5 to 7, OJ/l-1, the air volume blown out from the air outlet is 14, which hits the cone and the rectifier plate.
By burning under conditions of 0% by weight or more, air flows in the combustion air region at the center of the cone, and the wall surface f
In the fuel vaporization region -1, oxygen-deficient combustion gas sucked in by the high-speed air flow and fuel gas gasified by the heat of the cone flow, and these two flows do not mix with flows that do not fall within the flammability limit. It is intended to do so. According to the present invention, this phenomenon depends on the suction of oxygen-deficient combustion gas, and structurally it depends on the relationship between the air outlet and the diameter of the cone cylindrical part, and the cone shape. By setting the aperture area of the cone outlet, the flow velocity of the air-fuel mixture in the flame propagation and mixing zone is balanced to prevent the flame from flowing backward into the mixing zone, that is, from backfiring.

Furthermore, as mentioned above, in the combustion method of the present invention, suction of combustion gas into the burner cone is essential to achieve gastritis combustion, and the shape and dimensions of each part are determined to optimize the suction ω. ing.

In other words, if the diameter of the air outlet is too small, the air blowing speed will be too high, colliding with the baffle plate and applying back pressure toward the rear, making it difficult to suck in the circulating gas and making the combustion noise louder. On the other hand, if it is too large, the air flow rate will slow down and the suction of circulating gas will become worse. Therefore, the diameter is φ3
7 to φ48, the air blowing speed is 19IIl/S to 1
0m/s is desirable.

In addition, if the length of the outlet is too short, the air that blows out will not flow in the axial direction and the spark from the igniter will not be able to flow into the fuel injection area, resulting in ignition failure or combustion gas inside the burner cone. The air mixes, creating a yellow flame inside the burner cone and making a loud combustion noise.

Therefore, the relationship between the diameter and length of the air outlet is preferably such that the length is approximately 1/2 or more of the diameter, and the length is 20 mm.
llI11 or more is desirable.

In addition, the diameter of the outlet and the diameter of the cylindrical part of the burner cone are closely related, and if the diameters of the two become close, for example, if the cylindrical diameter of the cone becomes smaller, the fuel gasified by the inhaled combustion gas will be reduced. Gas and air mix in the front half of the cone, creating a flame inside the cone.

Therefore, the half of the cylindrical portion of the burner cone must be at least 1.3 times the diameter of the air outlet. In addition, from the relationship of suction, it is desirable that the air blowout [1 cross-sectional area/(cross-sectional area of burner cone cylindrical part - cross-sectional area of air outlet) <1,
The difference between the cross-sectional area of the cylindrical part of the burner cone and the cross-sectional area of the air outlet must be 0.00077-ffl' or more, and the inner diameter of the cylindrical part of the burner cone is preferably φ48 or more.

That is, as a result, air flows in the center and vaporized fuel flows on the outside, and the two mix for the first time at the baffle plate and cone outlet constriction, and then a stable flame is formed in the combustion zone consisting of the baffle plate and the flame-holding ring. be done.

The shape of each of the above parts and judicial decisions will be further explained.

The presence or absence of suction of combustion gas can be confirmed by measuring the gas temperature at the suction port position when the combustion gas is combusted in the combustion chamber, with the suction port closed and when the suction port is opened.

As a result of measuring the temperature of an actual burner in which the method of the present invention was carried out, it was approximately 800°C when there was a suction port, but it was 400°C when the suction port was closed. From this, it can be assumed, albeit indirectly, that in the present invention, there is actually a circulating flow due to the provision of the suction port between the burner cone and the air outlet.

If the amount of combustion gas to be sucked is estimated based on the theory of thrust increase by Von K. Arllan, the measured value from the actual machine implementing the method of the present invention as described above shows that the temperature of the circulating gas to be sucked in at the suction port position is approximately When the suction port was closed at 800°C, the temperature decreased to about 400°C, so the composition of the circulating gas to be sucked was the same as the composition of the combustion gas,
Set the temperature to 800°C and sieve.

■When the resistance term is ignored According to Yon K. Arman's theory of thrust increase, the equation includes a resistance term: F, but the correction is made assuming that this can be ignored.

As a result, the amount of circulating gas sucked and the flow rate (n) of combustion air are n-+1, that is, almost the same amount of combustion gas as the amount of combustion air is suctioned and circulated.

The amount of heat held by this circulating gas is as shown below.

Approximately 15,0OOKcal /H (MAX value) ■When taking into account the resistance term In the actual machine (fluid resistance due to ceramic surface roughness, fluid resistance due to the shape of rectifier plate, burner cone) (i.e. fluid resistance due to flow path changes) Due to factors such as resistance), the resistance term F' cannot be ignored. When this term becomes large, suction disappears and blue flame combustion becomes impossible.

■The suction amount has an optimal value based on the amount of heat required to vaporize the sprayed fuel and the amount of gas to prevent flame holding in the cone.The present invention is designed to maintain this optimal value by each component including the resistance term. The shape and dimensions of are determined to be the above shape and dimensions.

Therefore, in the present invention, the shape of the burner cone and the shape of the current plate are made as described above so as to reduce this resistance term as much as possible.

On the other hand, according to the present invention, the amount of oil sprayed on the burner cone and rectifying plate is determined by the amount of oil sprayed from the nozzle at the correct position, but does not hit the ceramic surface and flows out to the outside of the cone from the cone outlet. and the amount from the annular portion between the current plate. The amount of oil sprayed on the burner cone and baffle plate is calculated based on the nozzle spray angle of 60'.
It becomes 1% by weight.

However, in reality, the air flow around the nozzle (
It is possible that the value may differ from the calculated value due to air resistance, deflection, jet angle, angle, no deflection, and nozzle spray pattern.

For this reason, by measuring the oil that hits the ceramic surface, the amount will be 60Φ% by subtracting this time.

In the case of the present invention, during combustion, there are no oil droplets inside the cone that burn and disappear in the flame, and almost all of the oil droplets in the above-mentioned proportion reach the ceramic surface.

According to the present invention, approximately 60% of the liquid fuel sprayed from the nozzle reaches the burner cone and the inner surface of the baffle plate, which are heated by the high-temperature circulating gas sucked from the suction port, - After being sucked into and held by the ceramic support surface, it is instantaneously vaporized by the heat of the burner cone and rectifying plate to become a primary vaporized fuel body.

Also, among the fine oil droplets that do not reach the burner cone and the inner surface of the baffle plate, those that reach the fuel vaporization region are vaporized by the heat of the high-temperature circulating gas and become secondary vaporized fuel bodies.

This vaporized fuel and the high-temperature circulating gas sucked through the high-temperature combustion gas circulation area flow along the inner surface of the burner cone, and the area near the surface has oxygen below the lower combustion limit. degree. That is, an oxygen-deficient layer is formed near the inner surface of the burner cone, thereby preventing the formation of flame in the fuel vaporization region.

On the other hand, the central part of the burner cone is the combustion air air region where the air blown out from the air outlet flows. Although some fuel droplets are mixed in, the amount of these fuels is extremely small and the concentration is below the lower flammability limit. That is, the combustion air area is I! A redundant area is formed to prevent the formation of a flame.

At this time, due to the balance between the flame propagation speed and the air-fuel mixture based on the shapes and dimensions of each part described above, flame formation in the mixing part is prevented, and the flame is ignited at the end of the baffle plate and the small hole part of the baffle plate. In other words, the annular gap (18) formed between the current plate (8) and the outlet of the burner cone (6) is determined by the following equation: gap area/(passage area of air outlet + (cross-sectional area of cylindrical part of burner cone - air blowout area)). It is desirable that the cross-sectional area))>1, which means that the gap area should be >0.0015417/.Also, to prevent backfires, it is desirable that the gap area be <0.00667m, and as a result, the current plate The gap area including the small hole area is 0.00154Tn
'71J to 0.00667-IT/ is desirable.

The four parts formed behind the baffle plate serve as retention points for the airflow, and a portion of the high-temperature circulating gas remains in this part, becoming a source of ignition for the air-fuel mixture discharged from the burner cone outlet [1].

Therefore, a blue flame will appear from the end of the current plate and the small holes.

The concave portion of the baffle plate serves as an ignition source, and also has the role of completely dividing the burner space into eight zones without disturbing the combustion air flow. Therefore, an appropriate number of small holes are drilled parallel to the axis of the current plate near the peripheral edge and in a portion surrounding the top near the top, leaving an appropriate width at the top and middle of the current plate.

Further, the unburned gas that is not ignited at the end of the current plate flows along the inner and outer circumferential surfaces of the flame stabilizing ring and is ignited at the four parts behind the flame stabilizing ring.

The recess behind the above flame-holding ring is similar to the recess behind the current plate.
This becomes a retention point for the airflow, where high-temperature combustion gas accumulates and becomes a source of ignition for unburned gas that was not ignited at the end of the current plate. Therefore, a stable blue flame will also be formed at the end of the flame-holding ring.

A portion of the high-temperature combustion gas is sucked into the burner cone from the suction port as a circulating gas, and performs the heating of the burner cone and the vaporization of oil mist as described above.

As mentioned above, the heating of the burner cone by the circulating gas is performed by the gastritis combustion gas formed on the current plate and the flame-holding ring passing through the high-temperature combustion gas circulation area, being sucked from the suction port, and circulating within the cone. heat is transferred to the burner cone, but at this time, since the combustion gas flows near the cone wall, it is heated from both the inside and outside of the cone, shortening the rise time at the time of initial ignition. In addition, it is possible to supply a sufficient amount of heat necessary for vaporizing liquid fuel.

For example, under the maximum usage conditions of this burner, the amount of heat required for vaporizing liquid combustion is at most 1.000 Kcal/H.
However, this amount of heat is replenished from the amount of heat held by this combustion gas by sucking in combustion gas that is approximately 1.0 times the amount of combustion air jet, but this amount is only a small amount of the amount of heat held. Only about 7%.

Therefore, the efficiency of the present invention is greatly improved by employing the heating method by convective heat transfer to the burner cone.

Therefore, the present invention can realize complete gastritis combustion, and since the gasified fuel and combustion air are mixed, the mixing is good.
Even if the excess air ratio is made low, there is no generation of soot or -carbon oxide.

FIG. 5 shows how soot and carbon oxide are generated when a household water heater is equipped with a burner that implements the method of the present invention.

Since Co/Co2≦0.02 is generally considered to be the standard for CO2 emissions, the combustion range of this burner should be 02 = 1 (vo1%゛) or more, preferably in terms of smoke degree. 02 = 1, 5 (vo1%) or more.

In the method of the present invention, in order to prevent flame holding within the cone, the oxygen concentration near the wall surface is below the lower combustion limit.
No soot or tar was observed on the ceramic surface during 0HR operation.

In addition, the present invention was based on the recognition that the noise caused by the maximum air shock flow in the plane of the flame holder is the main cause of combustion noise, and the structure of the flame holder was moved from immediately after the nozzle to the cone outlet, so that combustion is prevented. The flame is formed by the open end, and the operation is quiet.

By the way, when we measured the noise of a water heater equipped with a burner that implemented the method of the present invention, the noise was 40 to 43 dB (A).
65 to 70dB (c) and l.

On the other hand, in the method of the present invention, a burner cone and a rectifier plate are formed by pouring into a slurry prepared by mixing and stirring powders of 30 to 75% silicon, 10% clay, and 50% by weight silicon nitride, and molding the resulting molded product. The fact that it is made of porous Reramic with a porosity of 20-50% obtained by nitriding and firing at 1350-1650°C also greatly contributes to achieving a perfect blue flame and preventing the generation of soot.

In gastritis combustion, as mentioned above, oxygen must diffuse through the vaporized gaseous fuel, but in the method of the present invention, approximately 60% of the oil mist sprayed from the fuel spray nozzle is in the burner cone. However, since these are made of water-absorbing porous ceramic with the above-mentioned structure, the fuel is once sucked into the ceramic and held there, and then heated by combustion in the burner. It quickly evaporates into gas due to the heat of the cone.

That is, the vaporization of fuel by the burner cone and baffle plate is
This is largely due to the water absorbency of the ceramics that make up these materials, and the water absorbency is influenced by the porosity of the ceramic.

Incidentally, burner cones were prototyped from various ceramic materials and their properties during combustion were investigated, and the results are shown in the table below.

From the table above, it is clear that materials with low porosity do not cause gastritis;
Taking thermal shock resistance into consideration, it can be seen that silicon nitride is the most excellent material for the burner cone and current plate.

1.5 “1・*R#4(J)$11(D 1$1gc
l-y°゛1 Illustrate.

FIG. 2 is a longitudinal cross-sectional view of a main part of a water heater equipped with a burner embodying the present invention.

In this illustrated example, the burner (
A) has an output of 35,000 Kcal/l-1, and is provided at a heat exchanger flange pipe (10) provided on the peripheral wall of a cylindrical combustion chamber (2), facing into the combustion chamber (2).

The burner (A) includes a fuel spray nozzle (3), an air outlet (4) provided around the fuel spray nozzle (3) surrounding the nozzle (3), and a fuel spray area of the fuel spray nozzle (3). The burner cone (6) is installed surrounding the burner cone (6), the current plate (8) is provided at the outlet of the burner cone (6), and the flame holding ring (9) is provided in front of the current plate (8). We are prepared.

The air outlet (4) is formed in a straight cylindrical shape that opens from the heat exchanger flange pipe (10) in a direction perpendicular to the axial direction of the combustion chamber (2), and the rear part is connected to the blower outside the combustion chamber (2). Contact Kazedo (12) at (11).

Further, a nozzle holder (1) is provided coaxially within the air outlet (4), and the tip of the fuel spray nozzle (3) held in the nozzle holder (1) is located at the front end of the air outlet (4). The opening faces the center of a burner cone (6), which will be described later.

The air outlet has an inner diameter of 40φ and a total length of 55m to 7m.The burner cone has a cylindrical inner diameter of 63φ and an outlet inner diameter of 10mm.
4, the total length is 100m/m, the expansion angle of the expansion part is 30°
, the distance from the air outlet to the rear end is 20 m/m, the opening outer diameter of the rectifying plate is 90φ, the total length is 45 m/1, the distance from the air outlet to the rear end is 82111/+11 burner]-n front end to front end The flame stabilizing ring has an outer diameter of 130φ, an inner diameter of 104φ, a total length of 15111/m, and a distance from the front end of the burner cone of 12111/m. ing. The diameter of the nozzle holder (1) is 21$1.

Also, regarding the air blown out from the air outlet (4) by the blower (11), there is no need to worry about wind! 0.5 Noimo 1, 3NTl?
/m, 19m /sea≧Suita speed≧ko0IIl/S
It must be eC, and in this example, the rumor is 0.
．． 8NT11''/I11, and the blowing speed is set to 16 m/sea.

The fuel spray nozzle (3) is a nozzle with a spray angle of 60° and has a conventionally well-known structural form, and the rear part of the fuel spray nozzle (3) is connected to the fuel supply source (14) through the fuel pipe (13) that passes through the nozzle holder (1) in the axial direction. Contact.

The oil pipe (13) is equipped with an electromagnetic pump (15) in the middle, and the nozzle (3) is operated by the electromagnetic pump (15).
The amount of oil sprayed from the tank is set to 4.3 J/t1.

In addition, the above oil amount is 2.6 to 7. OJ/H is required.

The burner cone (6) has the shape shown, that is, a cylindrical portion with a straight or slightly tapered rear part (6a
) is formed, and at the same time, a conical widening part (6b) is formed at the front end of the cylindrical part (6a) and extends forward in a conical shape, and is held by a suitable holding member (17). The fuel spray nozzle (3) is provided coaxially with the fuel spray nozzle (3) in front of the air outlet (4) with a gap (5) between the air outlet and the air outlet (4).

The burner cone (6) has a cylindrical part inner diameter > 48 years, a cylinder part inner diameter/air outlet inner diameter> 1.3, an air outlet passage area/(
Cylindrical section cross-sectional area - air outlet cross-sectional area) <1. Cylindrical section cross-sectional area - air outlet cross-sectional area <0.00077TT1'; in this example, the inner diameter of the cylindrical section is 63φ, and the cylindrical section cross-sectional area - The cross-sectional area of the air outlet is -0.0O173t+t.

Also, the total length of harp-]-n (6) is 1001it/II
The expansion part (6b) expands forward at an expansion angle of 30'f7), and its front end has an inner diameter of 104φ, and there is a gap between the rear end and the front end of the air outlet (4). (5) is 20+
It has a width of 11/m.

The opening at the rear end of the burner cone (6) and the air outlet (
The gap (5) between the combustion chamber (2) and the burner cone (6) utilizes the negative pressure generated around it due to high-speed air blowing from the air outlet (4). This constitutes a suction port (5) for sucking inward.

The current plate (8) is formed into a conical or hemispherical shape with an open bottom, with the convex surface facing the burner cone (6), and most of the plate is inserted into the burner cone (6). The burner cone (6) is provided coaxially with the burner cone (6), and an annular gap (18) is formed between its outer periphery and the outlet of the burner cone (6).

This current plate (8) should be formed to have a total length of 45 m/m.

, Aiga. . A small, Projects forward by 7m/rn from the front end.

In addition, the current plate (8) has a 6φ
Thirty-six small holes (7) are drilled.

The annular gap (18) formed at the outlet of the burner cone (6) by the baffle plate (8) and the burner cone (6) is the actual outlet of the burner cone (6). Passage area of outlet + (cross-sectional area of burner cone cylindrical part - cross-sectional area of air outlet)) > 1, gap area >0.00154i', and 0.01 to prevent backfire at the outlet of burner cone (6). 001
54　〈Gap area <0.00667 buds, in this example, 0.00 including 36 small holes (7)
410711'.

In addition, as long as the small hole (7) satisfies the above conditions for the annular gap (18), that is, the substantial outlet of the burner cone (18),
It is possible to slightly increase or decrease their number and diameter.

The burner cone (6) and the current plate (8) are made of ceramic whose raw materials are 42% silicon, 18% silicon nitride, and 40% clay, and are manufactured by the method described below.

That is, ethanol is added to powder raw materials of silicon and silicon nitride, and the mixture is ground in a cylinder mill for 4 hours.

At this time, ethanol is used instead of water because silicon and silicon nitride react with water and generate gas during pulverization.

After pulverization, X[tanol is removed by distillation and dried.

Next, -F crushed silicon and a garden opening agent (sodium polyacrylic acid) are added to the slurry of clay and water, mixed and stirred to create a casting slurry, and a burner cone (6) and a rectifying plate (
8) are cast and formed respectively.

Then, the rectifying plate (8) is machined with holes for small holes (7), and after drying, the molded body is baked in nitrogen at 1450° C. for 15 hours to obtain a product.

The physical properties of the burner cone (6) and current plate (8) according to the present invention, which were manufactured by the method specified above, are as shown in the table below.

Open pore porosity (%) 30 Bending strength (25℃) 13. OkO/111m' (7
00℃) 13.0 Composition (X-ray peak ratio) α5L3N4 1.0 β5L3N4 1.0 0' phase 2.3 Although the porosity can be changed by changing the temperature, the range that can be used as the burner cone (6) and the current plate (8) is from 50 to 20%, and in this example, it is 30%.

In addition, rubber press molding, injection molding, and casting molding are available as methods for molding the cone and current plate. Rubber press molding is advantageous in that it can speed up the molding process, but it requires cutting of the end surfaces of the molded product. The disadvantage is that the molding equipment required is expensive. Similarly, injection molding has the advantage of being able to achieve a high molding speed of 1.
Contains ~50% by volume of binder, so the base material is expensive, it takes a long time to heat and remove the binder, equipment for environmental regulations such as exhaust gas purification is required, and molding equipment is expensive. There is a problem with that.

On the other hand, casting molding cannot achieve a high molding speed, but it is advantageous in obtaining a homogeneous and thin molded product, and there is no need for cutting or debinding of the molded product. This method has the advantages of simple subsequent steps and low equipment costs, making it the most suitable method for forming cones and rectifier plates.

The flame-holding ring (7) is made of metal with excellent heat resistance and is formed into an annular body with a substantially V-shaped or U-shaped cross section, with the inner part of the ring facing the rectifying plate (6) and the burner cone (5). Aim the rectifier plate (6
) is provided in front of the

The flame stabilizing ring (9) has an outer diameter of 130 dl and an inner diameter of the same diameter as the exit part of the burner cone (6), that is, 104".
The length is 15 m x 1 m, and the rear end is located in front of the rectifier plate (8) at a distance of 12 II/Il from the prong end of the burner cone (6).

In addition, (19) in the figure is the igniter, and the fuel spray nozzle (
A pair of air blowers are provided at positions close to air outlet (4) that do not obstruct the flow of air from the air outlet (4).

Therefore, in the burner (A) that refuses, the blower (11)
When the electromagnetic pump (15) is operated and the igniter (19) is ignited, the fuel sprayed from the fuel spray nozzle (3) and the air outlet (
igniter (19) to the air mixture blown out from 4)
The spark ignites and a yellow flame is formed in the center of the burner cone (6).

Furthermore, the air is blown out from the air outlet (4) to produce a suction effect and suck the surrounding air.

As a result, the gap between the burner cone (6) inlet and the air outlet (4) is smaller than the burner cone (6) outlet.
That is, a circulating flow is generated which passes through the combustion gas suction port (5) and reaches the interior of the cone (6).

The atomized fuel is sucked into the burner cone (6) and instantly vaporized by its heat. The vaporized fuel forms an oxygen-deficient layer (a) along the inner surface of the cone (6) together with the circulating gas, and a constriction part (20) is formed between the outlet part of the cone (6) and the current plate (8). flows into a cone (
6) Mixing with the combustion air flowing through the center is promoted.

The yellow flame inside the barboon (6) moves to the downstream part of the baffle plate (8) at the same time as the combustion gas is sucked in, where the -F2 mixture ignites and becomes a blue flame.

On the other hand, oil droplets sprayed from the spray nozzle (3) and not vaporized by the suctioned combustion gas are removed from the burner cone (6).
It hits the inner circumferential surface, especially the inner circumferential surface of the expanded part, but the cone (6)
Since it is made of porous ceramic that absorbs water, it is once sucked into the ceramic and retained. The cone (6) is heated to a high temperature due to convective heat transfer by high-temperature combustion gas.
-1171-Nishi λ Oone 1-Saury bait 1゛do゛L-Nakai 4
After one note, the flow flows to the outlet of the cone (6), and is mixed with air at the baffle plate (8) and the cone (20) at the outlet of the cone (6). ) It ignites in the recess at the back.

, V The recess behind the baffle plate (8) becomes a retention point for the airflow, and the high-temperature combustion gas is retained in this part and is released from the outlet of the cone (6), vaporizes, and lands on the fuel gas mixed with air. Becomes a fire source. Therefore, the small hole (7) made in the current plate (8)
This causes gastritis.

In addition, the current plate (8) is made of porous ceramics that have the same water absorption properties as the burner cone (6).
In addition to rectifying airflow and serving as an ignition source, it can also function as a fuel vaporization surface similar to the burner cone (6).

Further, the unburned gas that is not ignited at the end of the current plate (8) flows along the inner and outer peripheral surfaces of the flame-holding ring (9) and is ignited at the four parts behind the flame-holding ring (9).

Note: The four parts behind the flame-holding ring (9), like the four parts behind the baffle plate (8), serve as retention points for airflow, and high-temperature combustion gas remains in these parts, preventing ignition in the buff plate (8). It becomes a source of ignition for unburned gas. Therefore, stable gastritis will be present at the end of the flame-holding ring (8).

Therefore, the intended purpose can be achieved.

In addition, in this application, the output range is from 23,000 to 57,000
The present invention relates to a vaporizing burner of cal/t1, but for outputs higher than this, the desired purpose can be achieved by expanding the shape of the present application in a similar manner.

[Brief explanation of drawings]

The drawings show embodiments of the present invention. Figure 1 is a diagram showing separation of burner spaces in the method of the present invention, and Figure 2 is a sectional view of the main parts of a water heater equipped with a burner in which the method of the present invention is implemented. ,
Figure 3 is a front view of the burner, partially cut away.
Figure 4 is a flowchart that does not show the process of kerosene combustion.
The figure is a graph showing the occurrence of soot and monoxide fibers when the method of the present invention is carried out in comparison with when the conventional method is carried out. A...Burner 1...Nozzle holder 2...Combustion 3...Fuel spray nozzle 4...Air outlet 5
...High-temperature combustion gas suction port 6...Burner cone 6a...Cylindrical portion 6b...-expanding portion 7...Small hole 8...Brightening plate 9...Flame holding ring a. ... Nozzle area b... Combustion air area C... Fuel vaporization area d... Mixing area e... Combustion wt t... High-temperature combustion gas circulation vM area Patent applicant Totoki Co., Ltd. (Patent (Dear Office Examiner) 1. Description of the incident 1982 Patent Application No. 79728 2 Title of the invention Combustion method of liquid fuel vaporization burner 1939 Amendment (1) Page 7, line 8 of the specification [As thermal vaporization...] is corrected to [vaporize with heat...]. (2) In the same book, box 7, line 19, [...Fuel spray nozzle...] is corrected to [...Fuel spray nozzle...]. (3) The same book, page 10, line 1: “...-[140% by weight.
"..." is corrected to "...amount 40% by weight...". (4) Same book, page 10, line 11 [..., also, the rectifier plate
... j is 1" ... and in the mixing area, a rectifier plate...
・Correct to "." (5) Box 11, line 7 [...is the air...]
is corrected to "...but, the air...". (6) In the fourth line of page 12 of the same book, correct [half of...] to [the diameter of...]. (7) On page 14, line 20 of the same book, ``For this reason, the present invention makes the burner cone shape and the current plate shape as described above so as to make this resistance term as small as possible.''
Insert additional information. (8) Same book, page 15, lines 6 to 8 [For this reason...
Tonazu] is deleted. (9) In the same book, box 17, line 6, "...combustion air flow" is corrected to "...combustion air flow." (10) Next to page 17, line 12 of the same book: [This combustion air and the oxygen-deficient vaporized fuel are mixed at the outlet of the burner cone by promoting flow turbulence by the throttle formed by the baffle plate and the outlet of the burner cone. to ensure sufficient oxygen diffusion. ] Insert. (11) In the same book, page 20, line 3, 1 of liquid combustion is supplemented with ``of liquid twisting H...''. (12) Same book box, page 22, line 3 [... rectifier plate silicone]
``...'' is corrected to ``...straighten the rectifier plate...''. (13) Same book box, page 27, line 6 “<Q, 00077 耀・
...-1 is corrected to r>0.00077...". ;・ , 14) ya]□30*4i□12. Engineering. □er
-11, Iraizuru. ” [..., the powder will react with water if left as is, so it is heated to 175°C in air to make it stable against water. ”. (15) Figure 1 of the drawing will be corrected as shown in the attached sheet. Patent applicant: Totokiki Co., Ltd.

Claims (1)

[Claims] In a liquid fuel vaporization burner, there is a combustion air region in the center in front of the nozzle region, a fuel vaporization oxide layer is provided around it, and a mixing region, a combustion region, and a high-temperature combustion gas circulation region are sequentially formed in front of the nozzle region. The 8 zones are completely separated, and the majority of the oil droplets sprayed from the nozzle in the nozzle zone are applied to the porous burner cone and the porous baffle plate to form a blown fuel body and the fuel vaporized by the porous burner cone. The body is mixed with the high temperature combustion gas coming from the high temperature combustion gas circulation area, and some of the remaining oil droplets are mixed with the high temperature gas coming from the high temperature combustion gas circulation area to form a secondary vaporized fuel body, and the fuel vaporization area is combined. At the same time, the remaining oil droplets are mixed with a part of the combustion air in the combustion air region to form a mixed fuel body, and then the primary vaporized fuel body, the mixed fuel body, the residual vaporized fuel body of the combustion air, and the secondary vaporized fuel body are mixed. A combustion method in a liquid fuel vaporizing burner characterized in that a fuel body, a mixed fuel body, and combustion air are mixed to form a combustion gas body, and these combustion gas bodies are combusted in a combustion zone to obtain gastritis.