JPS6069415A - Liquid fuel evaporating burner - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a delay in ignition, by a method wherein a hollow annularly-structured secondary air outlet having pores formed therein is located to the cone outlet part of a burner and a number of pores are provided in the peripheral surface part of a flow uniformizing plate. CONSTITUTION:A high-temperature gas is stayed in a recess 22 in the back of a flow uniformizing plate 6, and the gas serves as an ignition source to form a stable blue flame through a number of pores 8 in the flow uniformizing plate 6. Further, the flame serves as an ignition source, and unburnt gas, not ignited at the back of the flow uniformizing plate 6, is mixed with the air fed through a secondary air supply ring 7 to ignite the mixture, and a stable blue flame is formed through the pores 8. This causes a flame to be stabilized as in a gas burner, prevents the occurrence of shake, and causes combustion noise to be reduced and becomes quiet.

Description

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

Conventionally, there are various structures for this liquid fuel vaporization type burner, but the liquid fuel gasification methods can be roughly divided into the following two types.

In other words, there are those that vaporize liquid fuel by dropping it onto a vaporization surface that has been preheated and heated using an electric heater or other heat source, and those that vaporize liquid fuel by supplying the fuel to a rotating disk or the like and using centrifugal force to scatter the fuel. This is brought into contact with a preheated vaporization surface, vaporized, mixed with air, and then combusted.

However, with these conventional methods, it is necessary to heat the vaporization surface in advance, and it takes time for combustion to occur.
If it is difficult to control the temperature of the vaporizing surface and the temperature becomes too high, tar will adhere due to the decomposition of the kerosene, which will prevent proper vaporization and cause deterioration of the combustion condition. It has drawbacks such as a complicated structure.

Therefore, the applicant of the present application has already applied for a liquid fuel vaporization burner shown in FIG. 3 as a solution to the above-mentioned problem.

To explain the one in Figure 3, the burner is in the combustion chamber (
1) Fuel spray nozzles (2) and 7 inserted into the fuel spray nozzle (2) and a burner cone (7) that surrounds the nozzle and is coaxial with the nozzle so that the sprayed fuel sprayed from the fuel spray nozzle collides with the inner peripheral surface.
5) and a rectifier plate installed at the front end of the burner cone (
The burner cone (5) is made of water-absorbing porous ceramic, and the front half of the burner cone (5) is made of water-absorbing porous ceramic. By expanding the fuel spray forward at an angle slightly narrower than the spray angle of the nozzle (2) so that the fuel spray ejected from the nozzle (2) hits the core, the fuel spray hits the burner cone (5). The unburned liquid is temporarily soaked inside the burner cone (5), and is evaporated and released as steam using the heat of the cone (5) heated by the combustion heat. (3) is once constricted into a conical shape in order to blow out air at high speed, and then the opening is made into a straight cylindrical shape, and a rectifier plate (6) is used to rectify the airflow and allow high-temperature gas to stay behind it. In order to achieve this, it is formed into a conical shape with an open bottom and a few holes (8) on the circumference, and the suction force generated by blowing out the air and the rectification of the air by the rectifier plate (6) are used. Combustion gas suction part (4) installed at the rear of the burner cone (5)
The high-temperature combustion gas is sucked into the burner cone (5) to promote gasification of the fuel, and the high-temperature gas remaining in the four parts (22) behind the baffle plate (6) is used as an ignition source to move the burner cone ( 5) A stable flame is formed at the outlet.

However, since the combustion engine shown in FIG. 3 performs combustion using only primary air, ignition delays tend to occur, resulting in flame fluctuations and loud combustion noise.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a liquid fuel vaporizing burner that has all the advantages of the burner shown in FIG. 3 and eliminates the above-mentioned problems of the burner shown in FIG.

The technical means taken by the present invention to achieve the above object basically consists of providing a secondary air Suita ring with a hollow ring-like structure with small holes at the burner cone outlet of the burner cone shown in Fig. 3, and rectifying the secondary air. A large number of small holes are drilled in the peripheral surface of the plate.

Hereinafter, an example of implementation of the present invention will be described based on the drawings.

In the figure, (1) is a combustion chamber, and (3) is a primary air outlet which is provided to protrude inward from the burner mounting flange (1') into the combustion chamber (1). 3) is opened in the burner mounting flange (1') of the combustion chamber (1),
The air passage (not shown) of the blower (not shown) is installed outside the combustion chamber (1).
A conical constriction part (
3b), and a straight cylindrical outlet part (3a) is provided at the tip of this constricted part (3b).

This primary air outlet (3) has an oil feed pipe (12) provided with a fuel spray nozzle (2) at its tip extending through its axial center.

Although the oil supply pipe (12) is not shown, it communicates with an oil supply source outside the combustion chamber (1) and is provided with an electromagnetic pump in the middle.

The fuel spray nozzle (2) has a conventionally well-known cap shape,
The spray angle is, for example, approximately 60', and it projects slightly from the tip of the primary air outlet (3) and faces the center of a burner cone (5), which will be described later.

In addition, at a position close to this fuel spray nozzle (2), there is a
A pair of igniters (13) are arranged at positions that do not obstruct the flow of air from the primary air outlet (3).

The burner cone (5) is made of water-absorbing porous ceramic, such as silicon nitride or sialon.
A ceramic fiber acid insulator (14) is wrapped around the outer periphery to retain the cracks in case of occurrence and to prevent impact during transportation.The cone is attached to the burner mounting flange (1°) of the combustion chamber (1). The atomized fuel that is held by the retaining ring (15) and the secondary air connecting pipe (16) to be described later and is injected from the fuel spray nozzle (2) in front of the primary air outlet (3) is inside the cone (5). 1 at the position where it hits the circumferential surface
It is provided coaxially with the fuel spray nozzle (2) with an appropriate gap (4) between it and the secondary air outlet (3).

This burner cone (5) has the shape shown in the figure, that is, a straight cylindrical part (5a) is formed at the contact part, and the cylindrical part (5a) expands forward continuously from the front end, and the expanded part is the fuel It expands at a slightly narrower angle than the spray angle of the spray nozzle (2).

The gap (4) between the opening at the rear end of the burner cone (5) and the primary air outlet (3) is the primary air outlet (3).
The combustion gas in the combustion chamber (1) is transferred to the burner cone (5) using the negative pressure generated around it by the high-speed primary air blowing from
), the size of the gap (4) being determined to be the size necessary to draw an optimum amount of combustion gas into the burner cone (5).

The cone holding ring (15>) is a ring (15a) that fits into the cylindrical portion (5a) at the rear of the burner cone (5).
) and a support arm (15b) attached to the ring part (15a) and extending rearward, and the support arm (15b)
b) The rear end of the burner handle (1 flange) of the combustion chamber (1)
1').

On the other hand, the secondary air connecting pipe (16) is made of a metal with excellent heat resistance such as stainless steel, and the combustion spray nozzle (2),
It is installed in the combustion chamber (1) parallel to the axis of the primary air outlet (3) and the burner cone (5), and the rear end is located inside the combustion chamber (1).
a secondary air intake (17) which extends slidably through the burner mounting flange (1') of the chamber (1) into the air passage (10) outside the chamber (1); The front end extends in front of the burner cone (5) and connects and supports a secondary air blowing ring (7).

This secondary air connecting pipe (16) is connected to a spring (18).
) to push the burner cone (5) backward.
A cone holding piece (19) is provided protruding from the outer surface at a position corresponding to the front end, and the cone holding piece (19) is attached to the burner cone (5).
The burner cone (5) is supported by being in contact with the front end surface of the burner cone (5) and sandwiching the front and back of the burner cone (5) together with the cone retaining ring (15).

The secondary air blowing ring (7) is formed into a hollow annular body made of stainless steel or the like, which has a diameter equal to or slightly larger than the diameter of the front end, and is supported by the secondary air connecting pipe (16) and is connected to the burner. It is provided in front of and coaxially with the cone (5), and the internal space communicates with the air passage (10) via a secondary space connection pipe (16).

The secondary air Suita ring (7) has a hollow elliptical cross-section or a shape close to it, and its long axis is angled toward the tip at an appropriate angle so that the blowing ring (7) does not interfere with the flow of primary air. is inclined outward, and its angle is preferably an intermediate angle between the opening angle of the expanded portion (5b) of the burner cone (5) and the opening angle of the rectifying plate (6), which will be described later.

In addition, this secondary air blowing ring (7) has a small hole-shaped blowing hole (9) suitably provided on the inner peripheral surface, and the blowing hole (
9) is opened diagonally forward so that the blown air does not obstruct the flow of primary air.

Inside the ring (7), there are 41 pieces of rectifier plate (6) (
20).

The rectifying plate (6) is made of heat-resistant metal such as stainless steel and is formed into a conical shape with a rounded bottom, and is attached to the secondary air blowing ring (7) at an appropriate interval. is inserted toward the inside of the burner cone (5), and there is an appropriate distance between it and the outlet of the burner cone (5).

The forward opening angle of this baffle plate (6) is slightly larger than the opening angle of the enlarged part (5b) of the burner cone (5), and as a result, a constricted part (21) is formed at the outlet of the burner cone (5). is formed.

Further, the rectifying plate (6) has a large number of small holes (8) perforated on its curved surface.

Therefore, a burner that is compliant with the air flow from the blower can
The liquid fuel that is blown out from the secondary air outlet (3) and sent from the fuel supply source via an external electromagnetic pump is sprayed from the fuel spray nozzle (2), and the sprayed fuel and primary air are mixed. The discharge of (13) causes ignition inside the burner cone (5), causing yellow flame combustion.

In addition, a part of the air sent from the blower is taken in from the secondary air intake (17) into the secondary air connecting pipe (16) in the air duct (10), and the air is transferred to the secondary air Suita ring (
7) is supplied as secondary air from the blow-off hole (9).

On the other hand, the primary air is blown out from the outlet part (3a) at the tip of the primary air outlet (3), thereby producing a suction effect.
Suction of ambient air.

As a result, a circulating flow is generated from the outlet of the burner cone (5) to the inside of the cone (5) through the gap (4) between the inlet of the burner cone (5) and the primary air outlet (3). .

After ignition, hot combustion gas is sucked into the burner cone (5) by the above-mentioned circulation action, and the atomized fuel is instantaneously vaporized by the heat. The vaporized fuel is promoted to mix with combustion air at the constriction section (21) between the outlet section of the cone (5) and the baffle plate (6).

The yellow flame inside the burner cone (5) moves to the downstream part of the baffle plate (6) at the same time as the combustion gas is sucked in, where the above-mentioned aikido ignites and causes gastritis.

At this time, if the diameter of the outlet part (3a) of the primary air outlet (3) is too small, the velocity of the primary air outlet will be too high, colliding with the current plate (6) and blowing backward. Apply back pressure,
The suction of combustion gas becomes poor, and conversely, if it is too large, the flow velocity of the primary air becomes slow and the suction of combustion gas becomes poor again.

In addition, if the flow rate of the outlet (3a) is too short, the primary air blown out will not flow in the axial direction, but will flow in the direction of the inclination of the conical constriction (3b), thereby preventing the spark from the igniter (13). The fuel cannot flow into the spray area, causing ignition failure.

Therefore, it is desirable that the relationship between the diameter and the length of the outlet portion (3a) of the primary air outlet (3) is such that the flow rate is about 1/2 of the diameter.

Also, the diameter of the outlet part (3a) and the burner cone tI:l)
It is closely related to the diameter of the -i tol note hp1m part (5a), and the diameters of both are close, for example, the cone (5).
If the diameter of the cylindrical part (5a) becomes small, the combustion gas to be sucked and the primary air will mix in the front half of the cone (5), causing a flame to start inside the cone (5).

Therefore, the diameter of the cylindrical part (5a) of the burner cone (5) needs to be larger to some extent than the diameter of the outlet part (3a) of the primary air outlet (3).

That is, as a result, the primary air flows in the center and the combustion gas flows in the outside, and the two mix for the first time at the baffle plate (6) and the cone (21) at the outlet of the cone (5), and the flame is formed at the outlet of the cone (5). is formed.

On the other hand, oil droplets sprayed from the spray nozzle (2) and not vaporized by the suctioned combustion gas are removed from the burner cone (5).
It collides with the inner circumferential surface, especially the inner circumferential surface of the expanded part (5b), but ]-
Since the tube (5) is made of water-absorbing porous ceramic, it is once sucked into the ceramic and retained. Since the cone (5) is at a high temperature due to the heat of combustion, the inhaled fuel quickly evaporates and vaporizes, flowing to the outlet of the cone (5) and passing through the small holes (8) of the current plate (6). The current is rectified, and the current plate (6
) The ignition occurs in the downstream part, that is, in the recess (22) behind the rectifying plate (6).

The concave portion (22) behind the baffle plate (6) becomes a retention point for the airflow, and the high temperature combustion gas is retained in this portion, and the cone (5)
) It serves as an ignition source for the fuel gas mixed with vaporized air released from the outlet. Therefore, a blue flame will come out from the many small holes (8) made in the current plate (6).

Furthermore, the unburned gas that is not ignited in the recess (22) of the current plate (6) is supplied from the secondary air blowing ring (7).
The secondary air blowing ring (7) is mixed with the secondary air and ignited.
Gastritis rises from the air outlet (9).

The difference in thermal expansion that occurs between the metal part and the ceramic part during combustion heating is due to the fact that the ceramic burner cone supports the secondary air Suita ring (7) and supplies secondary air to it. This is absorbed by holding the connecting pipe (16) and providing the connecting pipe (16) in a free state by slidably passing through the burner mounting flange (1') of the combustion chamber (1).

The current plate (6) does not necessarily need to be made of metal as described above, but can be made of porous ceramic that has the same water absorption properties as the burner cone (5), and is made of ceramic in this way. As a result, the baffle plate (6) can function as a fuel vaporizing surface in the same way as the burner cone (5) in addition to rectifying airflow and serving as an ignition source.

Note that (Z3) in the figure is a can body through which water passes, and the water inside the cough can body 23) is heated by the above-mentioned combustion.

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

(1) High-temperature combustion gas accumulates in the recess behind the rectifying plate.2.
This becomes a source of ignition for the fuel mixture gas, and stable gastritis is formed through the many small holes provided in the baffle plate. Further, this flame becomes an ignition source, and the unburned gas that is not ignited behind the rectifying plate is mixed with the air supplied from the secondary air blowing ring and ignited, forming stable gastritis from the small holes.

Therefore, the flame is stable like a gas burner, there is no fluctuation, and the combustion noise is low and quiet.

(2) Since the burner cone is made of water-absorbing porous ceramic, unburned liquid that hits the burner cone is sucked into the cone and released as steam, and high-temperature combustion gas is sucked. The heat gasifies the fuel sprayed from the nozzle at time m, and the mixture of the gasified fuel and air is promoted by a baffle plate installed at the outlet of the cone, resulting in combustion. At the same time, secondary air is supplied to the combustion section, so complete combustion can be achieved.

the result, a. Blue flame combustion without red flame.

b. Generation of soot and - generation of carbon oxide can be suppressed.

The CO excess air ratio can be lowered, and the combustion efficiency can be lowered.

d. The flame flow is short and the combustion chamber can be made smaller.

(3) Since the fuel gas is gasified by combustion heat, no special heating source is required, the structure is simple, and the initial start-up time is fast.

(4) Since the vaporizing surface of the burner cone has water absorption properties, even if the temperature of the cone itself rises and becomes considerably higher than the boiling point of the fuel, the phenomenon of fuel becoming granular and generating tar etc. does not occur.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the liquid fuel vaporization burner of the present invention, FIG. It is a schematic diagram showing an example. 1...Combustion chamber 2...Fuel spray nozzle 3...Primary air outlet 3a...Blower outlet part 4...Gap 5...
Burner cone 5a... Cylindrical part 5b... Expanded part 6... Current plate 7... Secondary air blowing ring 8...
Small hole 9...Blowout hole Applicant: Totokiki Co., Ltd. Procedural amendment January 2, 1982, 2, Name of the invention: Liquid fuel vaporizing burner 3, Relationship to the person making the amendment Patent Applicant name (AO8) Totoki Co., Ltd. 4, agent address 5-14-7 Hakusan, Bunkyo-ku, Tokyo ■Specification;
Page 4, line 15 [...hole (8)...J is...
The small hole (8)...''. ■In the same book, page 18, line 5, “...flowing...” was replaced with “・
...The length is corrected to...J. ■In the same book, page 18, line 7, [...fuel gas...] is corrected to [...fuel...].

Claims (1)

[Claims] A fuel spray nozzle inserted into the combustion chamber, a primary air outlet provided around the fuel spray nozzle and coaxially with the nozzle, and a primary air outlet provided around the fuel spray nozzle so that the sprayed fuel sprayed from the fuel spray nozzle collides with the inner peripheral surface. A burner cone, which has an appropriate gap in front of the nozzle and the primary air outlet, and is provided coaxially with these, and an appropriate gap between the front end of the burner cone and the front end thereof. The primary air outlet includes a rectifying plate provided at intervals, and a secondary air Suita ring surrounding the periphery of the rectifying plate and provided at an appropriate interval on the periphery, and the primary air outlet has a conical shape. The burner cone is made of water-absorbing porous ceramic and has a straight cylindrical part with a diameter larger than that of the primary air outlet at the rear. At the same time, a conical widening part is formed at the front end of the cylindrical part and continuously widens forward at an angle slightly narrower than the spray angle of the nozzle, and the current plate is formed in a conical shape with an open bottom. The secondary air blowing ring is installed with the convex surface facing the inside of the burner cone, and a large number of small holes are bored in the circumferential surface, and the secondary air blowing ring is formed in a hollow ring shape with small blowing holes in the circumferential surface. A liquid fuel vaporizing burner characterized by: