JPS643944Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid fuel vaporization burner, that is, a type of burner that gasifies and burns liquid fuel such as petroleum.

Conventionally, as this liquid fuel vaporization type burner, the one shown in FIG. 3 and disclosed in Japanese Patent Application Laid-Open No. 58-200911 is known.

To explain what is shown in FIG. 3, the flame holding plate 18
is provided inside the burner cone 4, and the jet of fuel sprayed from the fuel spray nozzle 2 collides with the flame stabilizing plate 18, causing air to be blown out from the air outlet 6 surrounding the fuel spray nozzle 2. They are mixed and combusted within the cone 4.

Further, the flame stabilizing plate 18 is shaped like a flat perforated plate in order to increase the collision effect.

Therefore, in the above-mentioned conventional method, the flame is formed on the flame holding plate 18 inside the cone 4, and the combustion area is limited to the inside of the cone 4 and becomes narrow, so the combustion noise is large, and the flame is generated by collision with the flame holding plate. Due to the turbulence of the flow, the pressure inside the cone 4 increases and inhibits the suction of combustion gas, so the sprayed fuel ignites before it is completely vaporized by the circulating high-temperature gas, so there are many red flames and a low blue flame rate. low. In order to avoid this, it is possible to make the holes in the flame stabilizing plate 18 larger, but if a large hole is made in the center, for example, more fuel will leak directly from the hole, and the mixture ratio with air will deteriorate, resulting in delayed ignition. The flame lengthens, and there are more red flames at the tip of the blue flame.

The purpose of the present invention is to eliminate the above-mentioned drawbacks, reduce combustion noise, and achieve complete blue flame combustion.To this end, the technical problem to be solved by the present invention is to solve the problem of vaporized fuel and , the combustion air is prevented from mixing inside the cone, and the flame is formed outside the cone.

Therefore, the technical means taken by the present invention in order to achieve the above-mentioned technical problem is that the fuel spray nozzle is provided facing into the combustion chamber, and the sprayed fuel sprayed from the fuel spray nozzle collides with the inner circumferential surface. is arranged coaxially with and surrounding the fuel spray area of the nozzle,
The rear part has a burner cone with a combustion gas suction part, a rectifying plate provided at the front end opening of the burner cone, and a straight cylindrical blow-out port surrounding the nozzle and provided coaxially with it. The burner cone is made of water-absorbing porous ceramic, and has a front half that expands forward at an angle slightly narrower than the spray angle of the fuel spray nozzle, and a rear half that is cylindrical. The baffle plate is formed into a hollow conical or hemispherical shape with an open bottom, leaving an appropriate width at the top and middle part on the circumference, and a part near the circumferential edge and a part surrounding the top near the top. A suitable number of small holes are drilled parallel to the axis of the current plate, with the convex side facing the burner cone side, and the small holes near the circumferential end located near the outlet end of the burner cone. , and by inserting the baffle plate into the burner cone outlet with an appropriate distance between it and the outlet end of the burner cone, the burner cone acts as a vaporizer and the baffle plate controls the flow inside the cone. It has a rectifying effect, a mixing effect of the constricted part formed by the cone outlet and the current plate, and a flame-holding effect of the small holes on the current plate.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In the figure, A indicates a burner, which is provided in a portion of a heat exchanger flange pipe 9 provided on the peripheral wall of the cylindrical combustion chamber 1 so as to face the inside of the combustion chamber 1.

The burner A includes a fuel spray nozzle 2, a burner cone 4 provided surrounding the fuel spray area of the fuel spray nozzle 2, a baffle plate 5 provided at the outlet of the burner cone 4, and a burner cone 4 provided surrounding the fuel spray nozzle 2. It is equipped with an air outlet 6.

The air outlet 6 is provided so as to face the inside of the combustion chamber 1 from the heat exchanger flange pipe 9, and the rear end is connected to the blower 1 through an opening 10 formed at the rear end of the flange pipe 9.
A straight cylindrical blow-off port 6a is formed at the tip of the combustion chamber 1 in a direction orthogonal to the axial direction of the combustion chamber 1, and communicates with the air passage 12 of the combustion chamber 1.

Further, the air outlet 6 extends through the oil pipe 13 at its axial center.

The oil supply pipe 13 connects to an oil supply source 14 outside the combustion chamber 1.
In addition, an electromagnetic pump 15 is provided in the middle.

The fuel spray nozzle 2 has a conventionally well-known structure, is formed so that the spray angle is, for example, approximately 60 degrees, and is connected to the tip of the oil feed pipe 13 so as to face the center of the burner cone 4, which will be described later. .

A pair of igniters 16 are disposed close to the fuel spray nozzle 2 so as not to obstruct the flow of air from the air outlet 6.

The burner cone 4 is made of water-absorbing porous ceramic, and has a straight or slightly tapered cylindrical rear half and a conical front half that expands forward at an angle slightly narrower than the spray angle of the fuel spray nozzle 2. The fuel spray nozzle 2
It is attached to the heat exchanger flange pipe 9 on the side wall of the combustion chamber 1 coaxially with the fuel spray nozzle 2 and the air outlet 6, surrounding the fuel spray nozzle 2 and the air outlet 6 so that the sprayed fuel jetted from the expansion part 4a collides with the inner circumferential surface of the expanded part 4a. .

Although not shown in the drawings, it is desirable that the burner cone 4 be provided with some kind of protective means, such as wrapping ceramic fiber around its outer periphery, in order to hold it in place in the event of a crack and to prevent impact during transportation.

Furthermore, the burner cone 4 has a substantially straight cylindrical portion 4b, and the combustion gas suction portion 3 is attached to the cylindrical portion so that its opening area has a required area to achieve suction of an appropriate amount of combustion gas. 4b
The holes are appropriately opened along the circumferential direction, and a current plate 5 is provided at the front end opening, that is, the outlet.

The combustion gas suction section 3 has a structure in which the cylindrical section 4b of the burner cone 4 is formed long and its rear end is directly fixed to the rear end of the flange pipe 9 in the illustrated embodiment. Although the burner cone 4 is held in place using a suitable holding member such as a stay, the cylindrical shape 4b of the burner cone 4 is shortened and its rear end is opened near the air outlet 6, and this opening is may be used as the combustion gas suction section 3.

The current plate 5 is made of water-absorbing porous ceramic and is formed integrally with the burner cone 4 into the shape shown in the figure.

That is, the current plate 5 is formed into a hollow conical or hemispherical shape with an open bottom, and is inserted into the outlet of the burner cone 4 with its convex surface facing inward to the burner cone 4 and coaxially with the burner cone 4. The burner cone 4 is connected to the burner cone 4 via a connecting piece 17 at an appropriate location on the circumferential surface thereof.

The baffle plate 5 has a forward opening angle slightly larger than the opening angle of the widened part 4a of the burner cone 4, and its front end is made to substantially coincide with or slightly protrude from the outlet end of the burner cone 4. 4 and the baffle plate 5 form a constriction part 8 at the outlet of the burner cone 4 that has an appropriate spacing effective for not inhibiting the suction of combustion gas and promoting mixing of vaporized fuel and air. do.

Further, an appropriate number of small holes 7 are bored in the current plate 5.

Note that this current plate 5 does not necessarily need to be molded integrally with the burner cone 4 as described above, but can be molded separately from the burner cone 4 and fixed to the burner cone 4 or flange pipe 9 using a suitable mounting member. You may also do so. Furthermore, the current plate 5 can also be made of a metal with excellent heat resistance, such as stainless steel.

The small hole 7 is formed by leaving the top part of the current plate 5, that is, the center part, in a circular shape, and leaving the middle part in the shape of a band of an appropriate width, and forming a part sandwiched between the circular part left in the center and the band-shaped part left in the middle part. and an appropriate number of holes are provided at the peripheral edge portion surrounding the outside of the upper part of the band.

Therefore, the small holes 7 formed in the peripheral end portion of the current plate 5
is located near the outlet end of the burner cone 4.

Further, all of the small holes 7 are opened parallel to the axis of the burner cone 4.

Thus, the burner A blows out air supplied from the blower fan 11 from the air outlet 6 along the fuel spray nozzle 2. This blowing of air creates a negative pressure in the surrounding area, and together with the rectification of the airflow by the rectifying plate 5, the air in the combustion chamber 1 is transferred to the combustion gas suction section 3.
and into the burner cone 4. As a result, a circulating flow is generated from the air outlet 6 through the constriction section 8 between the burner cone 4 and the baffle plate 5, and from the combustion gas suction section 3 to the inside of the burner cone 4.

Next, let the spark fly from the igniter 16. When liquid fuel such as kerosene is sprayed from the fuel spray nozzle 2 in this state, a mixture of the sprayed fuel and air is formed. At the same time, the spark from the igniter 16 ignites this mixture, and a yellow flame is formed in the center of the burner cone 4.

After ignition, hot combustion gas is sucked into the burner cone 4 from the combustion gas suction section 3 by the circulation action, and the atomized fuel is instantaneously gasified.

Mixing of the fuel and air thus gasified is promoted by the mixing action of the constriction section 8 between the burner cone 4 and the baffle plate 5 provided at the center of the outlet of the burner cone 4. On the other hand, the yellow flame inside the burner cone 4 sucks the combustion gas from the combustion gas suction section 3, and at the same time moves to the outlet section of the burner cone 4, where the mixture is ignited and completely combusted. Therefore, combustion is blue flame combustion.

This movement of the combustion position causes combustion gas with a low oxygen concentration to be sucked in, resulting in a lack of oxygen near the wall inside the burner cone 4, making it impossible to maintain flame adhesion in this area, and causing the fuel gas and air at the outlet of the burner cone 4 to become insufficient. This is achieved by moving the flame into a zone where it mixes with the

As a result, the flame is not formed in a closed space, but at the open end, resulting in quieter combustion noise.

In order to achieve the movement of the combustion position, it is necessary to suppress the mixing of the fuel gas gasified by the combustion gas with a low oxygen concentration sucked inside the burner cone 4 and the combustion air. cone 4
It is installed at the outlet with the convex side facing the burner cone side, and is formed in a conical or hemispherical shape that does not impede the flow, so that no turbulence occurs inside the cone 4 and the vicinity of the wall surface of the cone 4 is Mixing of the flowing fuel gas and the combustion air flowing in the center inside the cone 4 can be suppressed.

Furthermore, suppression of mixing of fuel gas and combustion air is closely related to the length and diameter of the straight outlet part of the air outlet 6, the diameter of the straight part 4b of the burner cone 4, and the area of the combustion gas suction part 3. ing.

That is, if the diameter of the air outlet part 6a of the air outlet 6 is too small, the air blowing speed will be too high, colliding with the rectifier plate 5 and applying back pressure to the rear, resulting in poor suction of combustion gas. On the other hand, if it is too large, the air flow rate will slow down and the suction of combustion gas will become worse.

Furthermore, if the length of the blow-off port 6a is too short, the blow-out air will not flow in the axial direction and will not only collide with and mix with the combustion gas, but also cause the spark from the igniter 16 to flow into the fuel spray area. This will cause ignition failure.

Therefore, it is desirable that the relationship between the diameter and length of the air outlet portion 6a of the air outlet 6 is such that the length is about 1/2 or more of the diameter.

Further, when the diameter of the blow-off port 6a and the diameter of the cylindrical portion 4b of the burner cone 4 become close to each other, for example, when the diameter of the cylindrical portion 4b of the cone 4 becomes small, fuel gas and air gasified by the combustion gas to be sucked are transferred to the cone 4. Mixing occurs in the first half of the cone 4, causing a flame to start inside cone 4.

Therefore, the diameter of the cylindrical portion 4b of the burner cone 4 needs to be at least 1.3 times the diameter of the air outlet portion 6a of the air outlet 6.

That is, as a result, the air flows in the center and the fuel gas flows in the outside, and the two mix for the first time at the baffle plate 5 and the cone section 8 at the outlet of the cone 4, and a flame is formed at the outlet of the cone 4.

On the other hand, unburned particles of fuel that are not gasified by the combustion gas collide with the inner peripheral surface of the expanded portion 4a of the burner cone 4, but since this is made of water-absorbing porous ceramic, the fuel is absorbed into the ceramic. Once it is inhaled and held, it is immediately evaporated and gasified by the heat of the burner cone 4 heated by combustion, and ignited at the outlet of the cone.

At this time, the intake combustion gas with low oxygen concentration flows near the inner wall of the burner cone, so the flame cannot be maintained inside the burner cone and ignition occurs at the cone outlet. However, as mentioned above, the fuel evaporates and gasifies on the ceramic surface of the inner wall of the burner cone, so the vicinity of the inner wall of the burner cone is
This results in a fuel gas-rich, oxygen-poor composition, which further hinders flame attachment in this area.

When the current plate 5 is made of water-absorbing ceramic, it has the same effect as the burner cone 4,
Combustion becomes even better as unburned particles that hit the current plate are gasified.

Furthermore, since the concave portion of the baffle plate 5 becomes a negative pressure zone of the air, high-temperature combustion gas stagnates in this portion, and this high-temperature gas is transferred to the constricted portion 8 between the cone 4 and the baffle plate 5.
provides a source of ignition for the mixture of fuel gas and air flowing through it.

As a result, a blue flame appears all around the end of the rectifying plate 5.

The small holes 7 around the center of the baffle plate 5 rectify the high-temperature combustion gas that remains inside the baffle plate 5, thereby reducing combustion noise caused by the turbulence of this gas.

In addition, the small holes 7 near the peripheral edge of the current plate 5 are
It acts as an ignition source to rectify the internal gas and maintain stable ignition around the edges of the rectifier plate.

In order to maintain the flow from inside the burner cone to the inside of the rectifier plate and to perform a rectifying action inside the rectifier plate, small holes around the center hole and at the peripheral edge of the rectifier plate should be It must be parallel to the axis of the current plate.

In addition, if there are no small holes on the baffle plate, there will be no rectifying action inside the baffle plate, as described above, which will not only increase combustion noise, but also cause combustion due to delayed ignition because there is no ignition source at the peripheral edge. Due to the instability and lack of flow from inside the cone to the inside of the baffle plate, the flow velocity of the mixed gas at the constriction between the cone outlet and the baffle plate increases, which increases the risk of blowout and lift combustion. will occur.

In addition, if there is a hole in the center of the current plate, a lot of fuel leaks directly from this hole, which worsens the mixing with air, resulting in delayed ignition, longer flames, and more red flames at the tip, resulting in soot. This increases the risk of incomplete combustion.

Furthermore, if there are small holes throughout the current plate, in addition to the phenomenon that occurs when there is a hole in the center, the balance between the pressure inside the burner cone and the pressure inside the current plate will be upset, and the blue flame will not come out from the small holes. The combustion gas inside the baffle plate passes through the small holes and flows back into the burner cone, creating a flame inside the burner cone. As a result, combustion noise increases.

Since the present invention has the above configuration, it has the following advantages.

(1) By forming the burner cone and, in some cases, the baffle plate installed at its front end opening, from water-absorbing porous ceramic, unburned liquid is temporarily sucked into the ceramic and then released as steam. The combustion gas is sucked into the burner cone, and the heat instantly gasifies the fuel sprayed from the nozzle.
Moreover, since the mixing of the gasified fuel and air is promoted at the outlet of the burner cone by the baffle plate, complete combustion can be achieved at the outlet of the burner cone, resulting in combustion with blue flames without red flames. As a result, the generation of soot and carbon monoxide can be suppressed, the excess air ratio can be lowered, and the combustion efficiency can be improved.

Also, since the length of the flame is short, the combustion chamber can be made smaller.

(2) The current plate is formed into a conical or hemispherical shape with an open bottom, and is installed at the burner cone outlet with its convex face facing inward, so that high-temperature combustion gas remains in the concave portion of the current plate. This serves as an ignition source for the fuel gas, which ignites toward the open end of the burner cone, making it possible to form a stable flame at the outlet of the burner cone, as well as flame formation occurring at the open end of the burner cone. The combustion noise is small and quiet.

Moreover, since the small holes are provided at the peripheral end of the current plate, the ignition is stable and a stable flame can be maintained.

(3) The conical or hemispherical shape of the baffle plate does not impede the flow, which rectifies the flow inside the cone, prevents the formation of flames due to the mixing action of fuel and air inside the cone, and also rectifies the flow. Therefore, suction of the circulating gas can be maintained, and the heat necessary for vaporizing the atomized fuel can be smoothly and effectively supplied.

(4) In the current plate, an appropriate number of small holes are formed parallel to the axis of the current plate near the peripheral edge and in the area surrounding the top near the top, leaving an appropriate width at the top and middle part. Therefore, the high-temperature combustion gas that remains in the rectifier plate recess can be rectified without being disturbed, and combustion noise caused by the disturbance can be reduced.

(5) Since the burner cone is made of water-absorbing ceramic, even if the temperature of the cone itself rises and reaches a temperature considerably higher than the boiling point of the fuel, unburned fuel that hits the cone will not become granular. , does not generate tar, etc.

Therefore, gasification of the fuel is not hindered by tar adhesion to the burner cone.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a liquid fuel vaporizing burner showing an embodiment of the present invention, Fig. 2 is a front view with a portion cut away, and Fig. 3 is an example of a conventional liquid fuel vaporizing burner. FIG. 1... Combustion chamber, 2... Fuel spray nozzle, 3...
Combustion gas suction section, 4... Burner cone, 5...
Current plate, 6... air outlet, 6a... outlet part,
7...Small hole, 8...Aperture part.

Claims (1)

[Scope of utility model registration request] A fuel spray nozzle is provided facing into the combustion chamber, and a fuel spray nozzle is arranged coaxially with the fuel spray area of the nozzle so that the sprayed fuel sprayed from the fuel spray nozzle collides with the inner peripheral surface. A burner cone having a suction part, a rectifier plate provided at the front end opening of the burner cone, and an air outlet having a straight cylindrical outlet part surrounding the nozzle and provided coaxially with the nozzle. Prepare,
The burner cone is made of water-absorbing porous ceramic, and has a front half that expands forward at an angle slightly narrower than the spray angle of the fuel spray nozzle, and a rear half that is cylindrical. It is formed into a hollow conical or hemispherical shape with an open bottom, and an appropriate number of small holes are formed near the peripheral edge and in a part surrounding the top near the top, leaving an appropriate width at the top and middle part on the peripheral surface. Each of the rectifier plates has a hole parallel to the axis of the current plate, with the convex side facing the burner cone side, and the small hole near the peripheral end is located near the outlet end of the burner cone, and the current plate is located near the burner cone. A liquid fuel vaporizing burner that is inserted into an outlet of a burner cone so as to form a constricted part at an appropriate interval between the burner and the outlet of the cone.