JPH07180807A - Liquid fuel combustion device - Google Patents

Abstract

PURPOSE:To enable a proper and stable combustion amount to be always obtained by a method wherein a fuel returning pump is arranged in the midway part of a fuel returning pipe and the return fuel is directly supplied again to an atomizing means. CONSTITUTION:Particles with a small diameter and particles with a small particle diameter approximate to that of gasified gas in fuel fine particles atomized by an atomizing means 1 are selected within a mixing chamber 6, particles with a large diameter are forcedly formed to have dew within the mixing chamber 6, supplied again directly to the atomizing means 1 from the bottom part of the mixing chamber 6 by a fuel returning pipe 17 and they are not returned back to a specified oil surface device 4. Accordingly, it is satisfactory that a fuel supplying pump 2 is operated to supply a specified amount of supplying irrespective of a value of the returning volume of fuel. With such an arrangement as above, it is possible to get always a proper and stable combustion amount at the time of transfer from a starting of the combustion device to its stabled operation time, or a variation in fuel returning volume caused by variation in air temperature and a disturbance in equipment and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device using petroleum as a fuel, and more particularly to a domestic hot water heater and a heater.

[0002]

2. Description of the Related Art As a conventional combustion apparatus of this type, Japanese Patent Laid-Open No.
There is Japanese Patent Publication No. 141623. This content will be described with reference to FIG.

In FIG. 2, reference numeral 31 is an atomizing means using a pressure spray nozzle or the like for spraying liquid fuel at high pressure, which is connected to a fuel supply pump 32 by a fuel supply pipe 33. The fuel supply pump 32 is connected to a fuel tank (not shown) via a constant oil level device 34. Reference numeral 35 is a combustion air passage provided around the atomizing means 31 and is in communication with a blowing means (not shown) using a blowing fan or the like.

Reference numeral 36 denotes a cylindrical mixing chamber, which is a curved side wall 3
An opening 38 of the air passage 35 is provided in a part of 7 so as to face the inside of the mixing chamber 36.
The spouting port 56 is also provided so as to face the inside of the mixing chamber 36. A lower portion of the mixing chamber 36 has an inclined bottom portion 39, and a fuel return pipe 47 is provided at the lowermost end, and one end portion of the fuel return pipe 47 communicates with the constant oil level device 34.

At the upper part of the transfer passage 42, there is provided a mixing passage 44 configured to gradually expand upward, and a porous flame port portion 45 provided in the middle of the mixing passage 44. .

Reference numeral 54 is a flow rate measuring means provided in the middle of the fuel return pipe 47, and a signal line 55 thereof is connected to a controller 58. A signal line 57 is connected from the controller 58 to the fuel supply pump 32. Then, the controller 58 uses the signal from the flow rate measuring means 54 to send the fuel supply pump 3
2 is controlled, the amount of fuel supplied is corrected, and the amount of combustion is adjusted. 51 is an air flow, 49 is atomized fuel particles, and 50 is a flame.

In the above structure, the fuel pressurized by the fuel supply pump 32 becomes the fuel particles 49 atomized by the atomizing means 31 through the fuel supply pipe 33 and is ejected into the mixing chamber 36 and the air from the air passage 35. Mixed. The fuel particles having a large particle diameter adhere to or fall on the wall surface, and only the fuel particles having a small particle diameter are mixed with the air flow and burn through the flame passage 45 through the transfer passage 42.

Large fuel particles adhering to or falling on the wall surface are recovered from the bottom 39 through the fuel return pipe 47 to the constant oil level device 34. At this time, the return amount is measured by the flow rate measuring means 54, and the data is used to control the fuel supply pump 32 via the controller 58 to always obtain an appropriate and stable combustion amount.

[0009]

However, the above conventional structure has the following problems.

The change in the return amount measured by the flow rate measuring means 54 is minute, and the flow rate measuring means 54 becomes expensive.

If the controller 58 attempts to finely control the fuel supply pump 32 based on the minute return amount change data, the controller 58 also becomes expensive.

As described above, it becomes expensive and it is difficult to commercialize it in terms of cost. Further, as the fuel supply pump 32, when the electromagnetic pump, that is, the coil, is energized, the plunger moves forward against the elastic force of the spring and the like, and when the energization is stopped, the plunger moves backward by the elastic force of the spring to perform the pump action. If you use one, the fuel supplied by one pump action is decided,
Since it is not possible to finely adjust the supplied fuel, it is difficult to continuously and stably maintain an appropriate combustion amount.

The present invention has been made to solve the above problems and has as its object to always obtain an appropriate amount of combustion in a combustion apparatus.

[0014]

In order to solve the above-mentioned problems, the liquid fuel combustion apparatus of the present invention has an atomizing means for atomizing liquid fuel, and a cylindrical mixture having the side wall facing the atomizing means. A chamber, a cylindrical transport passage that penetrates the top plate of the mixing chamber and is provided in the mixing chamber, a flame port provided at the top of the transport passage, and a bottom of the mixing chamber. In a combustion device having a fuel return pipe for liquid fuel, a fuel return pump is provided in the middle of the fuel return pipe, and the other end is used as a fuel supply pump for supplying fuel from the atomizing means to the atomizing means. It is connected to a fuel supply pipe that serves as a route to reach.

Further, in the above fuel return pipe, a pressure adjusting chamber having an appropriate volume is provided between the fuel return pump and the connecting portion between the fuel return pipe and the fuel supply pipe.

Further, a through hole is provided in an upper portion or a side portion of the pressure adjusting chamber.

The bottom of the pressure adjusting chamber is located higher than the ejection port of the atomizing means.

[0018]

With the above-described structure, the liquid fuel combustion apparatus of the present invention selects only particles having a small particle size among the fuel particles atomized from the atomizing means and having a particle size close to vaporized gas in the mixing chamber, and Particles with a large particle size are forced to condense in the mixing chamber and are supplied again from the bottom of the mixing chamber to the atomizing means by the fuel return pump via the fuel return pipe.
Since it is not returned to the constant oil level device, it is possible to always obtain a proper and stable combustion amount in response to fluctuations in the return amount at the start of the combustion device and increase in the return amount due to temperature drop. . In other words, the fuel returned by the fuel return pump is directly re-supplied to the atomizing means without passing through the fuel supply pump, so the fuel supply pump supplies the prescribed supply amount regardless of the amount of fuel returned. If you have.

Further, since the pressure adjusting chamber has an appropriate volume, that is, a fuel reservoir, even if the amount of fuel returned by the fuel return pump temporarily increases and the atomizing capacity of the atomizing means may be exceeded, the fuel is not supplied. There is no problem because it can be temporarily pooled.

Further, when the return amount of the fuel is small together with the fuel by the fuel return pump, air is also sent, but since this passes through the through hole of the pressure adjusting chamber, it does not affect the atomizing means.

That is, since the through hole is provided in the upper portion or the side portion of the pressure adjusting chamber, the fuel does not overflow but the air escapes. Of course, the pressure of the fuel from the fuel return pump is also adjusted by letting air escape from this through hole.

Further, since the bottom of the pressure adjusting chamber is located at a position higher than the ejection port of the atomizing means, the fuel from the fuel supply pump does not go to the atomizing means and does not go to the pressure adjusting chamber.

In this way, a proper and stable combustion amount can always be obtained even when there is a transition from the start of the combustion apparatus to a stable state, fluctuations in air temperature, fluctuations in the amount of fuel returned due to variations in equipment, etc. It will be.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, reference numeral 1 is an atomizing means using an ultrasonic atomizing nozzle or the like for atomizing and spraying liquid fuel by ultrasonic vibration, which is connected to a fuel supply pump 2 by a fuel supply pipe 3. The fuel supply pump 2 is connected to a fuel tank (not shown) via a constant oil level device 4. Reference numeral 5 denotes a combustion air passage provided around the atomizing means 1 and is in communication with a blowing means (not shown) using a blowing fan or the like.

Reference numeral 6 is a cylindrical mixing chamber, and an opening 8 of the air passage 5 is provided in a part of the curved side wall 7 so as to face the inside of the mixing chamber 6, and the atomizing means 1 is opened from this opening 8. Spout 2
6 is also provided so as to face the inside of the mixing chamber 6. The air passage 5 is provided with respect to the side wall 7 in a tangential direction or a direction close thereto. The lower part of the mixing chamber 6 has an inclined bottom 9
The return port 10 is provided at the lowermost end, and the fuel return pipe 17 is connected to the return port 10.

The upper part of the mixing chamber 6 is covered with a top plate 11, and a cylindrical transfer passage 12 is provided in the center of the top plate 11 so as to penetrate the top plate 11. The lower end of the transfer passage 12 extends below the position where the opening 8 of the air passage 5 in the mixing chamber 6 faces, and is provided with a gap 13 from the bottom 9. A mixing passage 14 configured to gradually expand upward is provided at an upper portion of the transport passage 12, and a porous flame port portion 15 provided in the middle of the mixing passage 14.

A fuel return pump 16 is provided in the middle of the fuel return pipe 17, and is connected to the pressure adjusting chamber 18 having an appropriate volume via the fuel return pipe 17. A fuel supply pump 2 for supplying fuel from the atomizing means 1 to the atomizing means 1 from the pressure adjusting chamber 18 via a fuel return pipe 25.
Connecting portion 24 with the fuel supply pipe 3 which is a path leading to
It is connected to the.

Further, the bottom portion of the pressure adjusting chamber 18 is arranged at a position higher than the ejection port 26 of the atomizing means 1,
A through hole 22 is provided in the upper portion or side portion of the pressure adjusting chamber 18. 21 is air flow, 19 is atomized fuel particles, 2
0 is flame.

In the above structure, a blowing means (not shown)
Is activated, an air flow 21 flows through the air passage 5 into the mixing chamber 6. Since the airflow 21 flows into the mixing chamber 6 from the tangential direction, it swirls along the inner wall of the curved side wall 7 and descends along the inclined bottom portion 9 while rotating around the periphery of the transfer passage 12, Passing through the gap 13, the transport passage 12
To reach the flame mouth portion 15.

At this time, when the fuel supply pump 2 is operated, the fuel is sent to the atomizing means 1 through the fuel supply pipe 3,
The atomized fuel particles 19 are ejected into the mixing chamber 6.
The atomized fuel particles 19 are swirled along the curved side wall 7 and the inclined bottom portion 9 while mixing with the air flow 21, and only the fuel particles having a small particle size are mixed with the air flow in the transport passage 12. And is ejected from the flame nozzle 15. Then, ignition is performed by an igniter (not shown), a flame 20 is formed on the flame nozzle portion 15, and combustion is continued.

Large fuel particles attached to or dropped on the curved side wall 7 or the inclined bottom 9 wall surface pass through the fuel return pipe 17 from the return port 10 at the lowermost end of the bottom 9 of the mixing chamber 6. The fuel is returned to the pressure adjusting chamber 18 by the fuel return pump 16.

The fuel from the fuel supply pump 2 and the return fuel from the pressure adjusting chamber merge at the connecting portion 24 between the fuel return pipe 25 and the fuel supply pipe 3 and are supplied together to the atomizing means 1. The atomizing means 1 atomizes the supplied liquid fuel by ultrasonic vibration and sprays it from the ejection port 26.

A through hole 22 is provided in the upper portion or side portion of the pressure adjusting chamber. However, when the return amount of the fuel is small, the fuel returning pump 16 sends air together with the fuel, so that the through hole 22 is provided. This is because the pressure of the fuel return pump 16 is released by, for example, removing the air. In this way, the pressure of the fuel return pump 16 does not adversely affect the atomizing means 1.

Here, the bottom of the pressure adjusting chamber 18 is the atomizing means 1
Since it is located higher than the spout 26 of
The fuel from the fuel supply pump 2 goes to the pressure adjusting chamber 18 and does not overflow from the through hole 22 of the pressure adjusting chamber 18.

Since the fuel return pipe 25 from the bottom of the pressure adjusting chamber 18 to the connection portion 24 with the fuel supply pipe 3 also functions as a container as a fuel reservoir, the volume of the pressure adjusting chamber 18 is taken into consideration. You can decide.

Therefore, the pressure adjusting chamber 18 is not always necessary depending on the volume of the fuel return pipe 25. However, since it is necessary to release the air from the fuel return pump 16 and adjust the pressure as described above, it is better to provide an air escape hole for allowing only the air to escape without overflowing the fuel in a part of the fuel return pipe 17 (25). Needless to say, the structure may be such that air is released from the fuel reservoir when atomizing the liquid fuel with the ultrasonic atomizer of the atomizing means 1.

At this time, the fuel returned by the fuel return pump 16 is directly supplied to the atomizing means 1, and the fuel supply pump 2
Therefore, the fuel supply pump 2 may supply a prescribed supply amount regardless of the return amount of fuel.
Since the fuel supply pump 2 has the oil suction port 23 below the oil level of the constant oil level device 4, only the liquid fuel is supplied to the atomizing means 1 through the fuel supply pipe 3.

Therefore, there is an effect that a proper and stable combustion amount can always be obtained even when the fuel return amount changes due to a transition time from the start of the combustion apparatus to a stable time, a change in temperature, a variation in equipment, and the like. .

Further, in the mixing chamber 6, since the fuel particles having a small particle size are sorted, the fuel particles are sufficiently mixed with the air flow 21 so that the fuel particles are sent to the flame port portion 15, and the fuel particles are also mixed. It is instantly vaporized and a blue flame can be obtained by premixed combustion.

In this system, heating means such as a heater is provided in the bottom portion 9 of the mixing chamber 6 so that the dewed fuel is not vaporized and vaporized, so that tar components, which are vaporization residues, are less likely to accumulate.

[0042]

As described above, according to the combustion apparatus of the present invention, the following effects can be obtained.

(1) A fuel return pump is provided in the middle of the fuel return pipe so that the return fuel is directly supplied to the atomizing means again and is not returned to the constant oil level device. The fuel supply pump can always maintain a proper and stable combustion amount as long as the specified supply amount is supplied, irrespective of the change in the return amount due to the transient change, the temperature change, and the device variation.

(2) In the fuel return pipe, a pressure adjusting chamber having an appropriate volume is provided between the fuel return pump and the connecting portion between the fuel return pipe and the fuel supply pipe. Even if the adjustment chamber serves as a fuel reservoir and the fuel returned by the fuel return pump temporarily exceeds the atomizing capacity of the atomizing means, there is no problem such that the fuel can be temporarily pooled and the fuel overflows.

(3) Also, when the fuel return amount is small together with the fuel by the fuel return pump, air is also sent, but since this air escapes from the through hole in the upper or side portion of the pressure adjusting chamber, it affects the atomizing means. Does not reach. Of course, the pressure of the fuel from the fuel return pump is also adjusted by letting air escape from this through hole.

(4) Since the bottom of the pressure adjusting chamber is located higher than the ejection port of the atomizing means, the fuel from the fuel supply pump does not go to the atomizing means and does not go to the pressure adjusting chamber.

In this way, a proper and stable combustion amount can always be obtained even if there is a change in the amount of fuel returned due to a transition from the start of the combustion apparatus to a stable state, a change in temperature, a variation in equipment, or the like. It will be.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view of a main part of a conventional combustion device.

[Explanation of symbols]

 1 Atomizing Means 2 Fuel Supply Pump 3 Fuel Supply Pipe 4 Constant Oil Level Device 5 (For Combustion) Air Passage 6 Mixing Chamber 12 Transfer Passage 15 Flame Portion 16 Fuel Return Pump 17 Fuel Return Pipe 18 Pressure Adjustment Chamber 22 Through Hole 24 Connection part between the fuel return pipe 25 and the fuel supply pipe 3 26 Spouting port

Claims (4)

[Claims] 1. An atomizing means for atomizing a liquid fuel, a cylindrical mixing chamber with the atomizing means facing a side wall, and a top plate of the mixing chamber are penetrated through and provided in the mixing chamber. In a combustion device including a tubular transfer passage, a flame port provided at an upper portion of the transfer passage, and a fuel return pipe for liquid fuel provided at the bottom of the mixing chamber, a fuel return pipe is provided in the middle of the fuel return pipe. Liquid fuel combustion characterized in that a fuel return pump is provided, and the other end is connected to a fuel supply pipe which is a path from the atomizing means to a fuel supply pump for supplying fuel to the atomizing means. apparatus. 2. The liquid fuel combustion apparatus according to claim 1, wherein in the fuel return pipe, a pressure adjusting chamber is provided in a path from the fuel return pump to a connecting portion between the fuel return pipe and the fuel supply pipe. . 3. The liquid fuel combustion apparatus according to claim 2, wherein the pressure adjusting chamber is provided with a through hole at an upper portion or a side portion thereof. 4. The liquid fuel combustion apparatus according to claim 2, wherein a bottom portion of the pressure adjusting chamber is located at a position higher than an ejection port of the atomizing means.