JP3019452B2 - Liquid fuel combustion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid fuel combustion apparatus used as a heat source for hot water supply / heating equipment and the like.

[0002]

2. Description of the Related Art In recent years, in oil-fired equipment, there has been an increasing demand for an increase in the instantaneousness and a variable width of a combustion amount, a reduction in noise, and a reduction in the size of the equipment.

[0003] Conventionally, as a combustion method of this type of liquid fuel combustion device, there are roughly two types: a method in which the fuel particles obtained by atomizing the liquid fuel by a spraying device are directly used; and a method in which the liquid fuel is once vaporized and burned. .

For example, in the former spray combustion, as shown in FIG. 5, liquid fuel supplied from a fuel tank 1 is pressurized by an electromagnetic pump 2 and is ejected from a pressure spray nose 3 through a supply pipe 4 to be atomized. Is sprayed into the combustion chamber 6. On the other hand, the combustion air is supplied to the combustion chamber 6 through the ventilation path 5 by the ventilation fan 7. At this time, a combustion reaction occurs with the liquid fuel sprayed from the pressure spray nozzle 3 to form a flame. In the latter case, as shown in FIG. 6, the liquid fuel supplied from the fuel tank 8 is formed by the oil feed pump 9 through the oil feed pipe 10 through the oil feed pipe 10 into the vaporizer cylinder 14 in which the electric heater 13 is embedded from the nozzle 11. Vaporization chamber 12 at high temperature
The liquid is sent out as droplets to be heated and vaporized.

On the other hand, combustion air is supplied to a vaporization chamber 12 from a throat portion 17 provided on the outer periphery of the nozzle 11 through a ventilation path 16 by a ventilation fan 15. At this time, the fuel is mixed with the vaporized fuel, and a flame is formed at the flame port 18 provided in the combustion chamber 19.

[0006]

However, in the above conventional spray combustion (FIG. 5), the fire length increases due to the large particle size of the liquid fuel ejected from the pressure spray nozzle 3 and atomized. In addition, the combustion noise cannot be reduced because the combustion noise is generated by a popping sound when the fuel particles rapidly boil by the flame. Further, when the jet flow velocity is lowered to adjust the combustion amount, the atomization state is extremely deteriorated, the particle diameter of the fuel becomes large, and the combustion becomes poor, so that the combustion amount variable width is extremely small. In addition, the vaporization combustion (FIG. 6) requires a liquid fuel to be vaporized, which complicates the structure, and requires a heating source and power consumption for vaporization. Further, since a preheating time for raising the temperature of the vaporizing cylinder 14 and the vaporizing chamber 12 is required, instant ignition combustion cannot be performed and instantaneousness is poor. As described above, the conventional liquid fuel combustion device is
There was a problem that the instantaneousness of combustion rising and noise reduction were insufficient, and the variable width of the combustion amount was small.

The present invention has been made to solve the above-mentioned problems, and has an instantaneous start-up of combustion, low noise and small size.
It is an object of the present invention to provide a liquid fuel combustion device that can increase a range of adjusting a combustion amount.

[0008]

In order to achieve the above object, the present invention provides an electric vibrator for generating vibration, a vibrator connected to the electric vibrator, and a front end face of the vibrator. An atomizing unit comprising a liquid fuel supply unit for supplying the liquid fuel to the nozzle, a valve unit which comes into contact with the front end surface of the vibrating body and opens and closes the front end surface of the vibrating body by vibration, and faces the atomizing unit inward. An atomizing chamber, and a primary air supply provided in one of the atomizing chambers.
It has a combustion section provided in communication with the other of the atomization chamber, and a secondary air supply section for supplying air to the combustion section.

[0009]

According to the present invention, the contact surface between the distal end face of the vibrating body and the valve portion is opened and closed by the vibration of the distal end face of the vibrating body. During this opening and closing, an extremely thin liquid film is formed between the abutting surface of the vibrating body and the valve part, and the liquid film is continuously hit by the shearing force, and uniform and fine particles are formed in the atomization chamber. Can be generated. The adjustment of the atomization amount can be widened by adjusting the supply amount of the liquid fuel. Therefore, even in the case of a small combustion amount, atomization of the liquid fuel can be ensured, and the combustion amount variable width can be expanded. The air supplied from the primary air supply unit to the atomization chamber transports the atomized liquid fuel to the combustion unit and acts as premixed air. Can be made larger than diffusion combustion. Accordingly, the length of the flame formed in the flame outlet is reduced, and the size of the apparatus can be reduced. Furthermore, the air for combustion from the secondary air supply unit is added to the air-fuel mixture of fine particles of liquid fuel and air conveyed to the combustion unit, resulting in a combustible air-fuel mixture. it can. In addition, since combustion of the fine particles of the liquid fuel reduces the combustion noise, the noise of the apparatus can be reduced.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 and 2, reference numeral 20 denotes an atomizing unit.
For example, an electric vibrator made of lead zirconate titanate porcelain or the like, which is made of a pair of vibrators electrode-coated with silver on both end surfaces and electrically connected in parallel to generate a vibration. 21 and a metal, such as duralumin or stainless steel, which is tightly joined to one outer end face (silver electrode side) 21 a of the electric vibrator 21, converges the vibration generated by the electric vibrator 21, and A vibrating body 22 capable of transmitting the vibration amplitude to the front end face 23 of the vibrating body 22 is connected to a front end face 23 of the vibrating body 22 via a pipe 24a from a liquid fuel source (not shown) so that the liquid fuel is supplied to the front end face 23. A liquid fuel supply section 24 as a supply passage, a valve section 25 abutted at a predetermined pressure by an elastic body 26 or the like on an end surface 23 of the vibrating body 22, and a vibrating body 2.
Vibrating body 2 so that tip surface 23 of valve 2 and valve portion 25 match.
A recess 23a is formed at the center of the distal end surface 23 of the vibration member 2 and a projection 25a is formed at the valve portion 25.
The contact surface 27 between the valve 3 and the valve portion 25 is the tip surface 23 of the vibrating body 22.
It opens and closes due to the vibration of. And 28
Reference numeral denotes an atomization chamber provided with the atomization unit 20 facing inward. One of the atomizing chambers 28 is a primary air supply section 29 which is an air supply path connected to a blowing source 30 via a blowing pipe 30a, and the other is a combustion section 32 which is connected to the atomizing chamber 28 via a conveying path 31. Are provided in communication. The combustion part 32 is provided with a flame port 32a. 33 is a secondary air supply unit that connects the air pipe 3
Air is supplied from the supply port 32b to the combustion unit 32 via the port 3a. The operation in the above configuration will be described. FIG. 2 is a diagram for explaining the operation of the atomizing unit 20. When the vibrator driving device (not shown) is activated, the electric vibrator 2
1 (FIG. 1) is driven, and the distal end surface 23 of the vibrating body 22 is vibrated with an appropriate vibration amplitude, and this vibration causes the contact surface 27 between the vibrating body 22, the distal end surface 23 and the valve portion 25 to have a vibration frequency. Open and close synchronously. FIG. 2A shows a state in which the distal end surface 23 of the vibrating body 22 is open, and the liquid fuel is supplied from the liquid fuel supply unit 24 to the distal end surface 23 of the vibrating body 22. The gap formed between the tip surface 23 of the vibrator 22 and the valve portion 25 substantially coincides with the vibration amplitude, and the liquid fuel forms an extremely thin liquid film L. FIG. 2b then shows the state of the transitional phase towards closing,
The gap volume formed between the distal end surface 23 of the vibrating body 22 and the valve portion 25 is reduced, and the liquid film existing when the vibrating body 22 is fully opened forms a minute droplet Ld on the outer periphery of the distal end surface 23 of the vibrating body 22. FIG. 2C shows the closed state, in which the distal end surface 23 of the vibrating body 22 and the valve 25
And is atomized as a group of fine particles D, and is formed into a very thin liquid film uniform with a constant vibration amplitude. Uniform atomization can be obtained.
Then, by adjusting the supply amount of the liquid fuel to the distal end surface 23 of the vibrating body 22, the atomization amount can be varied widely.
Next, FIG. 1 will be described. By the operation of the atomizing unit 20, the liquid fuel is sprayed into the atomizing chamber 28 as a group of fine particles having a uniform particle diameter. Then, the atomized liquid fuel is sufficiently mixed with the air by the air supplied from the primary air supply unit 29. The mixture of the fuel and the air passes through the conveying path 31 while increasing the degree of mixing, and the combustion part 32
Sent to A secondary air supply unit 33 is provided in the combustion unit 32.
The combustion air is supplied through the supply port 32b from the combustion chamber, and is supplied as a combustible air-fuel mixture to the combustion chamber (not shown) from the flame port 32a. Form. As described above, an extremely thin liquid film generated when the contact surface 27 between the distal end surface 23 of the vibrating body 22 and the valve portion 25 is opened and closed, and the liquid fuel becomes fine particles due to the shearing force applied to the liquid film and is atomized. It mixes with the air supplied to the chamber 28, the degree of mixing is improved in the transport path 31, and the combustion section 32 is supplied with combustion air, so that excellent combustion characteristics can be obtained. Further, according to the atomization unit 20, the amount of atomization can be varied widely, so that even in the case of a small combustion amount, atomization of the liquid fuel can be ensured, and the combustion amount variable width can be expanded. Further, the air supplied from the primary air supply passage 29 transports the atomized liquid fuel to the combustion section 32 and acts as premixed air, so that premixed combustion can be performed at the flame port 32a, and the combustion speed can be reduced. Can be larger than diffusion combustion. Therefore, the length of the flame formed in the flame port 32a is reduced, and the size of the apparatus can be reduced.
Then, the combustion air from the secondary air supply unit 33 is added to the air-fuel mixture of the fine particles of liquid fuel and the air conveyed to the combustion unit 32 to form a combustible air-fuel mixture. be able to. Furthermore, when the particles of the liquid fuel are large as in the prior art, the combustion noise caused by the bursting noise when the particles boil rapidly due to the flame can be reduced by atomizing the liquid fuel, thereby reducing the noise of the apparatus. Can be achieved. Next, another embodiment of the present invention will be described with reference to FIGS.
This will be described. The difference of the atomizing unit 20 of FIG. 3 from the embodiment described above is that the vibrating body 22 is configured such that the cross-sectional area of the distal end surface 23 of the vibrating body 22 is smaller than the cross-sectional area on the joint side with the electric vibrator 21. It was that. According to the configuration of this embodiment, a large vibration amplitude is concentrated on the distal end face 23 of the vibrating body 22 due to the focusing effect of the vibration energy, and strong vibration is obtained. The effect of increasing the shearing force of the liquid film at the time of contact with the surface and obtaining finer and more uniform atomization is obtained. The difference between the liquid fuel combustion apparatus of FIG. 4 and the above-described embodiment (FIG. 1) is that the flow of the air supplied from the primary air supply unit 29 is perpendicular to the spray direction of the liquid fuel fine particles in the atomization unit 20. That is to say, it is configured to be the direction. Even with the configuration of this embodiment, the above-described effects can be sufficiently obtained.

[0012]

As described above, according to the liquid fuel combustion apparatus of the present invention, the following effects can be obtained. (1) Since the contact surface between the distal end surface of the vibrator and the valve portion opens and closes due to the vibration of the distal end surface of the vibrator, an extremely thin liquid is provided between the contact surface between the distal end surface of the vibrator and the valve portion during opening and closing. A film forming action and a tapping action by a shear force on the liquid film are continuously generated to obtain fine particles, a uniform extremely thin liquid film is formed with a constant vibration amplitude, and a stable shearing due to surface contact is achieved. By force, a uniform atomization of the particle size can be obtained.
This uniform and atomized liquid fuel is mixed with the air supplied to the atomization chamber, the degree of mixing is improved in the transport path, and the combustion section is supplied with combustion air, so that excellent combustion is achieved. Properties can be obtained. (2) Since the amount of atomization can be varied widely by adjusting the amount of liquid fuel supplied to the tip end surface of the vibrating body, atomization of the liquid fuel can be ensured even with a small amount of combustion, and the combustion amount can be varied. Can be expanded. (3) The air supplied from the primary air supply unit transports atomized liquid fuel to the combustion unit and acts as premixed air, so that premixed combustion can be performed at the flame port, and the combustion speed is diffused. Can be greater than combustion. Accordingly, the length of the flame formed in the flame outlet is reduced, and the size of the apparatus can be reduced. (4) Combustion air from the secondary air supply unit is added to the air-fuel mixture of fine particles of liquid fuel and air conveyed to the combustion unit to form a combustible air-fuel mixture. be able to. (5) In the case where the liquid fuel particles are large as in the prior art, the combustion noise caused by the popping sound when the particles boil sharply by the flame is reduced by burning the fine particles of the liquid fuel. Noise can be reduced. (6) In the vibrating body, the cross-sectional area of the front end surface of the vibrating body is smaller than the cross-sectional area of the side connected to the electric vibrator. As the strong vibration is obtained, the shearing force of the liquid film generated at the time of contact between the tip surface of the vibrator and the valve part increases, and uniform atomization with finer particles can be obtained. The effects of (1) to (5) can be promoted.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an atomizing apparatus according to an embodiment of the present invention.

FIG. 2A is a cross-sectional view of a main part showing a state in which a tip end surface of a vibrating body of the atomizing device is opened. FIG. Sectional view c is a cross-sectional view of a main part showing a state where the tip end surface of the vibrating body of the atomizing device is closed.

FIG. 3 is a sectional view of a main part of an atomizing device according to another embodiment of the present invention.

FIG. 4 is a sectional view of a main part of an atomizing device according to another embodiment of the present invention.

FIG. 5 is a sectional view of a main part of a conventional atomizing device.

FIG. 6 is a sectional view of a main part of another conventional atomizing device.

[Explanation of symbols]

 Reference Signs List 20 atomizing unit 21 electric vibrator 22 vibrating body 23 tip surface of vibrating body 24 liquid fuel supply unit 25 valve unit 28 atomization chamber 29 primary air supply unit 32 combustion unit 33 secondary air supply unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-39502 (JP, A) JP-A 62-174672 (JP, U) JP-A 58-7016 (JP, U) JP-A 56-174 107124 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F23D 11/34

Claims (2)

(57) [Claims] An electric vibrator for generating vibration; a vibrator connected to the electric vibrator; a liquid fuel supply unit for supplying liquid fuel to a tip end surface of the vibrator; An atomizing section comprising a valve section which abuts against the distal end face of the body and opens and closes the distal end face of the vibrating body by vibration; an atomizing chamber having the atomizing section facing inward; and A liquid fuel combustion device comprising: a primary air supply section provided on one side; a combustion section provided in communication with the other of the atomization chamber; and a secondary air supply section for supplying air to the combustion section. 2. The atomizing device according to claim 1, wherein the vibrating body is configured such that a cross-sectional area of a tip end surface of the vibrating body is smaller than a cross-sectional area of a connection side of the electric vibrator.