JP3304718B2 - Liquid fuel vaporization type 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 vaporization type combustion apparatus such as an oil fan heater.

[0002]

2. Description of the Related Art As a conventional liquid fuel vaporization type combustion apparatus,
For example, as shown in FIG. 5, a petroleum fan heater includes a fuel tank 1 for storing liquid fuel (kerosene) A, a vaporizer 2 for vaporizing kerosene A, and burning kerosene A vaporized by the vaporizer 2. And a fuel supply electromagnetic pump 4 for supplying kerosene A to the vaporizer 2.

The fuel supply electromagnetic pump 4 is disposed above the fuel tank 1 and has a discharge port connected to a fuel inlet 5 formed in the carburetor 2 by an oil feed pipe 6. It is connected to a fuel supply nozzle 7 inserted in kerosene A in the tank 1. Then, the fuel supply electromagnetic pump 4 sucks up the kerosene A through the fuel supply nozzle 7 and sends it to the vaporizer 2 through the oil supply pipe 6.

[0004] The vaporizer 2 is disposed in a vaporization chamber 8 and is provided with kerosene A.
Element 9 for vaporizing gas and vaporized gas C in which kerosene A is vaporized
And a heat recovery unit 11. Then, the kerosene A supplied from the fuel inlet 5 is vaporized and supplied to the burner 3 from the ejection nozzle 10. In the drawing, reference numeral 12 denotes an electromagnetic valve for opening and closing the ejection nozzle 10, and reference numeral 13 denotes a relief pipe for releasing kerosene A in the carburetor 2 to the fuel tank 1 when the ejection nozzle 10 is closed.

In the above configuration, when the operation switch of the oil fan heater is turned on, the vaporizer 2 and the burner 3
Starts preparation for booting. When the preparation is completed, the fuel supply electromagnetic pump 4 is driven. By driving the fuel supply electromagnetic pump 4, kerosene A in the fuel tank 1 is sucked up through the fuel supply nozzle 7 and sent to the carburetor 2 from the fuel inlet 5 through the oil supply pipe 6. The kerosene A is vaporized by the vaporizer 2 heated by a heater or the like, and the vaporized gas C is mixed with the primary air and burned by the burner 3. Further, the temperature of the heat recovery unit 11 becomes high due to the combustion flame, and the kerosene A is vaporized in a part of the vaporizing element 9 (near the fuel inlet 5). Thus, the oil fan heater warms the surroundings by sending out the hot air generated by the combustion to the outer periphery by the fan (not shown).

[0006] By the way, kerosene A becomes a deteriorated kerosene which is oxidized or polymerized when it is poorly stored and is exposed to air for a long time or is affected by ultraviolet rays. In this altered kerosene, a component having a high boiling point is formed, latent heat is increased, and tar and carbide are easily generated at a lower temperature than before the alteration. When this altered kerosene is used for a petroleum fan heater, the high boiling components in the altered kerosene are not vaporized in the vaporization chamber 8 of the vaporizer 2 but are tarified and accumulated in the vaporizer 2, and the kerosene A
And the amount of vaporization is reduced. Also, tar may adhere to the vaporizer 2 even if the fuel is burned for a long time.

As a method for solving this problem, Japanese Utility Model Application Laid-Open No.
JP-A-96525 has an air supply electromagnetic pump 14 in addition to the fuel supply electromagnetic pump 4 as shown in FIG.
It is disclosed that both pumps 4 and 14 are operated simultaneously to supply kerosene A and air B into the carburetor 2 at the same time. The air supply electromagnetic pump 14 is connected to an air inlet 15 formed in the vaporizer 2 by an air supply pipe 16.

Then, the air B and the kerosene A together with the vaporizer 2
, The high-boiling components remaining in the vaporizer 2 are exhausted by the air B so that tar does not accumulate in the vaporizer 2. Since the high boiling point component discharged by the air B is a small amount, when discharged from the ejection nozzle 10, it is in an atomized state, mixed with the vaporized gas C, and burned by the burner 3.

[0009]

However, kerosene A
And air B at the same time, two pumps 4,
It is necessary to make the discharge pressures of 14 the same. This is because, if there is a difference in the discharge pressure, the fluid having a low pressure is pushed back by the fluid having a high pressure at the junction of the fluids and cannot move forward. However, in the case where the air B is pumped as compared with the case where the kerosene A is pumped, the air B has a low viscosity, so that there are many leaks and it is difficult to obtain the same discharge pressure as the kerosene A. Therefore, in order to send the air B, a pump having a high discharge pressure is required, and the air supply electromagnetic pump 14 is expensive, and the cost is high.

[0010] In view of the above, an object of the present invention is to provide a liquid fuel vaporization type combustion apparatus capable of supplying air at low cost and removing tar in the vaporizer.

[0011]

Means for Solving the Problems According to the present invention, there is provided a vaporizer for vaporizing a liquid fuel, a burner for burning the fuel vaporized by the vaporizer, and a pump for supplying the liquid fuel to the vaporizer. In the provided liquid fuel vaporization type combustion apparatus, a supply means for supplying air to a carburetor is provided, and fuel and air are supplied alternately.

Here, the supply means is a pump interposed in an air supply path connected between the fuel tank and the fuel supply path of the carburetor, and is alternately driven with the fuel supply pump.
Thereby, the liquid fuel and the air are alternately supplied to the vaporizer, and when the air is supplied, the tar is discharged out of the vaporizer and does not adhere to the vaporizer.

As another supply means, a fuel supply pump is interposed in a fuel supply path for sending liquid fuel to the vaporizer,
An air supply path is provided in a fuel supply path on the upstream side of the pump. Thus, the supply of the liquid fuel and the air can be switched by opening and closing the air supply path, and the supply of the liquid fuel or the air to the vaporizer can be switched only by opening and closing one pump and the air supply path.

Further, a detecting means for detecting the state of the combustion flame is provided, and the supply of liquid fuel or air to the carburetor is switched and controlled according to the state of the combustion flame obtained by the detecting means. As a result, it is possible to grasp the decrease in the fuel in the carburetor, and it is possible to prevent the amount of fuel vaporized in the carburetor from excessively decreasing due to too long air supply time.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) An oil fan heater according to a first embodiment of the present invention will be described. As shown in FIG. 1, the oil fan heater includes a fuel tank 20 containing kerosene A and a kerosene A
, A burner 22 that burns the kerosene A vaporized by the vaporizer 21, a fuel supply electromagnetic pump 23 that supplies the kerosene A in the fuel tank 20 to the vaporizer 21, and a vaporizer 21. And a control unit 25 for controlling the combustion operation.

A fuel supply electromagnetic pump 23 is interposed in a fuel supply path (oil supply pipe) 26 connecting the fuel tank 20 and the carburetor 21. In addition, the oil supply pipe 26
An air supply passage (air supply pipe) 27 is connected downstream of the fuel supply electromagnetic pump 23.
An air supply electromagnetic pump 24 serving as a supply unit for supplying air B to the vaporizer 21 is interposed. In the drawing, reference numeral 28 denotes a connector having a three-way flow path, 29 denotes a fuel supply nozzle for sucking kerosene A in the fuel tank 20, 30 denotes an air supply nozzle for sucking air B, 31 denotes a suction port, and 32 denotes a flame. Hole.

As shown in FIG. 2, the vaporizer 21 has a filter 40 formed of a porous ceramic or the like inside.
And a heater 41 for heating the filter 40 to about 280 ° C., and a small-diameter jet nozzle 42 for jetting the vaporized kerosene A is provided opposite the burner 22, and is opened and closed by a solenoid valve 43. In the drawing, 44 is a lead wire connecting the heater 41 and the control unit 25, and 45 is a heat recovery unit.

The control unit 25 is a one-chip microcomputer having a RAM, a ROM, a CPU, a timer, and the like.
Two ignition heaters and the like are electrically connected. And
It has a function of preparing for activation such as preheating by turning on and off an operation switch, a function of driving both pumps 23 and 24 alternately for a predetermined time set in a timer, and the like.

In the above configuration, when the operation switch is turned on, the control unit 25 prepares for starting, such as preheating, and drives the fuel supply electromagnetic pump 23 when the preparation for starting is completed. Then, the kerosene A in the fuel tank 20 is sucked up by the fuel supply electromagnetic pump 23 through the fuel supply nozzle 29 and sent to the carburetor 21 through the oil supply pipe 26. The kerosene A supplied to the vaporizer 21 comes into contact with the high-temperature filter 40 and is vaporized. Then, the fuel is ejected from the ejection nozzle 42 and supplied to the burner 22 for combustion. At this time, the control unit 25 sets the drive time of the fuel supply electromagnetic pump 23 to a predetermined time, for example, 1 second.

When the driving time has elapsed, the control unit 25 stops the fuel supply electromagnetic pump 23, and then drives the air supply electromagnetic pump 24. This time, the air B passes through the air supply pipe 27 and is sent to the carburetor 21 via the oil supply pipe 26. The kerosene A remaining in the vaporizer 21 is pushed out by the air B together with the high-boiling component, and is ejected from the ejection nozzle 42. At this time, the control unit 2
In 5, the driving time of the air supply electromagnetic pump 24 is set to a predetermined time, for example, 1 second. Then, when this driving time has elapsed, the control unit 25 sets the air supply electromagnetic pump 24
Is stopped, and the fuel supply electromagnetic pump 23 is driven again for a predetermined time.

Thus, the control unit 25 alternately repeats the driving of the fuel supply electromagnetic pump 23 and the air supply electromagnetic pump 24 at predetermined time intervals, for example, every second, and when one is operating, the other is operating. Controlling to be stopped.
Each of the pumps 23 and 24 is provided with a check valve so that when one of the pumps is operated, the discharge pressure of the pump does not leak from the other pump. Therefore, the discharge pressure does not escape from the other pump, and there is no loss in each discharge pressure.

Here, it takes 5 to 6 seconds for the kerosene A to be completely discharged from the vaporizer 21. If the air supply electromagnetic pump 24 continues to be driven for more than this discharge time, the vaporizer 21 The kerosene A in the burner 22 is reduced too much and the combustion in the burner 22 stops. However, since the drive time of the air supply electromagnetic pump 24 is set to be shorter than the discharge time, the amount of kerosene A in the vaporizer 21 does not decrease too much, and the combustion is stably continued. Then, in the oil fan heater, the hot air generated by the combustion is sent to the outside by a blower fan (not shown) installed inside to heat the surroundings.

As described above, while the air supply electromagnetic pump 24 is operating, the air B is supplied into the vaporizer 21 and the high-boiling component of the kerosene A is discharged. Tar does not accumulate. In addition, both pumps 2
3, 24 are alternately driven, so that both pumps 23, 2
4 does not need to be the same discharge pressure, and the air supply electromagnetic pump 24 may have a lower discharge pressure than when both pumps 23 and 24 are simultaneously driven as in the conventional case. Therefore, the air supply electromagnetic pump 24 does not require a high discharge pressure, and may be an inexpensive pump compared to a conventional pump having a high discharge force, resulting in a very large reduction in cost.

(Second Embodiment) In the first embodiment, there is a problem that the cost is increased because two pumps are required. Therefore, in this embodiment, as shown in FIG. 3, a solenoid valve 50 is provided in place of the air supply electromagnetic pump 24, and a branch connected to the fuel supply nozzle 29 of the fuel supply electromagnetic pump 23 downstream of the fuel tank 20. An air supply path in which a solenoid valve 50 is disposed at the end of the pipe 51 is formed. Then, the fuel supply electromagnetic pump 23 is driven by the control unit 52 and the solenoid valve 50 is driven.
Is turned on and off at predetermined intervals to switch the supply of kerosene A and air B.

The solenoid valve 50 opens when it is turned on, opens the air inlet 53 of the branch pipe 51, and closes when it is turned off, closing the air inlet 53. Other configurations and operations are the same as those of the first embodiment,
Members having the same function are denoted by the same reference numerals.

In such a configuration, when the operation switch is turned on, the control unit 52 prepares for starting, and when the preparation for starting is completed, the fuel supply electromagnetic pump 23 that supplies kerosene A and air B to the carburetor 21 is driven. Let it. When the fuel supply electromagnetic pump 23 is driven, first, kerosene A in the fuel tank 20 is sucked up through the fuel supply nozzle 29 and sent to the carburetor 21 through the oil supply pipe 26. The kerosene A supplied to the vaporizer 21 is vaporized and becomes a vaporized gas, which is ejected from the ejection nozzle 42 and sent to the burner 22 for combustion.

When a predetermined time set in the timer of the control unit 52, for example, one second, elapses, the control unit 52 turns on the solenoid valve 50 and opens the air inlet 53. The fuel supply electromagnetic pump 23 starts to suck in the air B from the air inlet 53 through the branch pipe 51. Therefore, the suction power for the kerosene A decreases, and the kerosene A is not sucked up and is not supplied to the vaporizer 21, and only the air B is supplied to the vaporizer 21.

And a predetermined time set in the timer,
For example, when one second elapses, the control unit 52 turns off the solenoid valve 50 and closes the air inlet 53. When the air inlet 53 is closed, the suction force on the kerosene A returns again, and the kerosene A is supplied from the fuel tank 20 to the vaporizer 21. Hereinafter, the control unit 52 repeats the on / off operation of the solenoid valve 50 every predetermined time, for example, every 1 second.
As a result, kerosene A and air B are alternately supplied to the vaporizer 21 as in the first embodiment.

As described above, by turning on and off the solenoid valve 50 to open and close the air inlet 53, kerosene A and air B can be alternately supplied to the carburetor 21 by one pump. The same effects as those of the embodiment can be obtained, and the number of expensive pumps can be reduced, resulting in a very large cost reduction.

(Third Embodiment) By the way, if the supply time of the air B is too short, the effect of suppressing the tar due to the high boiling point component is lost. There is a problem of stopping. Therefore, in the present embodiment, as shown in FIG. 4, a detecting means for detecting the state of the combustion flame is provided, and the control unit 25 uses the state of the combustion flame obtained by the detecting means to supply kerosene A and air B to the carburetor 21.
The supply control is switched.

The detecting means is a frame rod 60 made of metal, and is provided above the burner 22. When an AC voltage is applied using the frame rod 60 and the burner 22 as a pair of electrodes, an ionic current flows through the combustion flame when the kerosene A is burned by the burner 22. This ion current changes depending on the state of the combustion flame, and when the supply of the burned kerosene A to the burner 22 decreases, the current value of the ion current decreases. Therefore, the control unit 25 determines the state of the combustion flame by outputting a detection signal of the ion current to the control unit 25.

The control unit 25 includes a frame rod 60
And the burner 22 are electrically connected so as to form a pair of electrodes, and a function of controlling switching between kerosene A and air B according to the state of the combustion flame is added. This is because when the current value indicating the state of the combustion flame falls below a certain value, the air supply electromagnetic pump 24 is stopped and the fuel supply electromagnetic pump is stopped even within a predetermined drive time of the air supply electromagnetic pump 24. 23 is driven to supply kerosene A. Other configurations and operations are the same as those of the first embodiment, and members having the same functions are denoted by the same reference numerals.

In such a configuration, when the operation switch is turned on, the control unit 25 prepares for starting. When the preparation for starting is completed, the fuel supply electromagnetic pump 23 is driven for a predetermined time to supply kerosene A to the vaporizer 21. Then, the kerosene A supplied to the vaporizer 21 is vaporized, supplied to the burner 22, and burned. Next, the air supply electromagnetic pump 24
Is driven to supply air B, and high-boiling components are discharged from the vaporizer 21. Here, the burning of kerosene A in the burner 22 is continued, but gradually the burner 2
The kerosene A supplied to 2 decreases due to consumption by combustion.

At this time, the flame rod 60 detects the state of the combustion flame, and when the current value of the ionic current becomes equal to or less than a predetermined value, the control unit 25 determines that the remaining amount of kerosene A in the vaporizer 21 is constant. Judge that it has decreased below the level. When this determination is made, the control unit 25 sends the air supply electromagnetic pump 24
Is stopped, the fuel supply electromagnetic pump 23 is driven, and kerosene A is supplied into the vaporizer 21 again. Normally, the same operation as in the first embodiment is repeated.

As described above, when the combustion flame is detected by the flame rod 60 and the kerosene A falls below a certain level,
By restarting the supply of kerosene A, there is no danger that the kerosene A will decrease too much and stop the combustion, and stable combustion can be continued. In the present embodiment, the detection means is provided in the first embodiment, and the supply of the air B and the supply of the kerosene A are switched depending on the state of the combustion flame. However, the same applies to the second embodiment. The effect is obtained.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made to the above-described embodiment within the scope of the present invention. For example, in the first and third embodiments, the air supply pipe 2
An accumulator and a solenoid valve are provided in the middle of 7 so that the accumulator is on the upstream side. Thus, when the air is compressed and stored, and the supply of air to the vaporizer is controlled by turning on and off the solenoid valve, the air supply pump only needs to be driven occasionally to accumulate the air in the accumulator, Power consumption can be reduced. In the second embodiment, instead of the solenoid valve 50, a two-position switching valve is provided at the junction of the fuel supply nozzle 29 and the branch pipe 51, and the two-position switching valve is turned on and off to thereby provide air and liquid. Switching of fuel may be performed. Further, in the embodiment of the present invention, the liquid fuel and the air are individually supplied. However, the supply may be switched between the supply of the liquid fuel and the air simultaneously and the supply of the air only.

[0037]

As is apparent from the above description, according to the present invention, the supply means for supplying air to the carburetor is provided, and the liquid fuel and the air are supplied alternately. Since the fuel supply pump is stopped, each burden is reduced. Therefore, when supplying air using a pump, the air supply pump may have a low discharge pressure, and the air supply pump does not require a high discharge pressure, so that a relatively inexpensive pump can be used. The cost is greatly reduced.

An air supply passage is provided in the fuel supply passage on the upstream side of the fuel supply pump, and the supply of liquid fuel and air is switched by opening and closing the air supply passage. Fuel and air can be supplied alternately, and only one pump is required, resulting in a very large cost reduction.

Further, a detecting means for detecting the state of the combustion flame is provided, and when the supply of the liquid fuel and the air to the carburetor is switched in accordance with the state of the combustion flame, the vaporized fuel supplied to the burner is provided. There is no danger that the combustion will stop due to excessive reduction of the amount, and stable combustion can be continued.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an oil fan heater according to a first embodiment.

FIG. 2 is a configuration diagram of a vaporizer.

FIG. 3 is a configuration diagram of an oil fan heater according to a second embodiment.

FIG. 4 is a configuration diagram of an oil fan heater according to a third embodiment.

FIG. 5 is a configuration diagram of a conventional oil fan heater.

[Explanation of symbols]

 Reference Signs List 20 fuel tank 21 carburetor 22 burner 23 fuel supply electromagnetic pump 24 air supply electromagnetic pump 25, 52 control unit 50 solenoid valve 51 branch pipe 60 frame rod

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F23D 11/02 F23D 11/40-11/44 F23K 5/18

Claims (4)

(57) [Claims] 1. A liquid fuel vaporization type combustion apparatus comprising: a vaporizer for vaporizing a liquid fuel, a burner for burning the liquid fuel vaporized by the vaporizer, and a pump for supplying the liquid fuel to the vaporizer. Supplying means for supplying air to the carburetor, and alternately supplying liquid fuel and air during combustion
And a means for evaporating a liquid fuel. 2. A fuel supply pump is interposed in a fuel supply path for sending liquid fuel to a carburetor, and an air supply path is provided in a fuel supply path upstream of the pump, and the air supply path is opened and closed. 2. The liquid fuel vaporization type combustion apparatus according to claim 1, wherein the supply of the liquid fuel and the air is switched every predetermined time . 3. A vaporizer for vaporizing a liquid fuel, and the vaporizer
A burner for burning the liquid fuel vaporized by the vessel;
And a pump for supplying liquid fuel to the gasifier
In a chemical combustion device, the fuel tank and the carburetor are connected.
The pump is interposed in the fuel supply passage,
Is connected to the air supply path, and the air supply path is connected to the vaporizer.
An air supply pump that supplies air is interposed,
Liquid fuel characterized in that both pumps are driven alternately
Vaporization type combustion device. 4. A detecting means for detecting a state of a combustion flame is provided.
Depending on the state of the combustion flame obtained by the detection means.
Control of the supply of liquid fuel and air to the gasifier
The liquid fuel vaporization according to claim 1, 2 or 3, wherein
Combustion device.