JPH0223942Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a vaporization type liquid fuel combustion device that vaporizes and burns liquid fuel, and in particular, it is used to efficiently empty tar adhering to the vaporization chamber, gas injection nozzle, etc. This invention relates to a vaporized liquid fuel combustion device that performs steam combustion.

[Conventional technology]

FIG. 6 is a sectional view showing a conventional vaporized liquid fuel combustion device, and 1 is a gas injection nozzle having a nozzle hole 2 at its tip. A needle tube 3 is connected to the rear end of the gas injection nozzle 1, the tip of a needle 4 inserted into the tube faces the nozzle hole 2, and the plunger 6 of an electromagnetic solenoid 5 is connected to the other end. There is. A return valve seat 8 having a return hole 7 is connected to the rear end of the plunger 6, and the return hole 7 is opened and closed by a return valve 9 provided at the rear end of the plunger 6. The plunger 6 returns to the return valve 9 by a return spring 10 inserted between its front end and the rear end of the needle tube 3.
However, it is biased so as to close the return hole 7.
A cap 11 is fitted to the rear end of the return valve seat 8, and a return pipe 1 communicating with the fuel tank 12 is connected to the cap 11.
3 are connected.

Further, the gas injection nozzle 1 is brazed to a cylindrical vaporizing pipe 15 having a heater 14 installed therein. In the vaporizing tube 15, a vaporizing chamber 19 having a brass wire mesh 18 is formed between the outer peripheral surface of the heater 14 and the outer cylinder 17, and the rear end side of the vaporizing chamber 19 is communicated with the gas injection nozzle 1 through a small hole 20. The front end side is connected to a liquid feeding pump 22 provided in the fuel tank 12 via a liquid feeding pipe 21 . In addition, 23
24 is a thermistor that detects the temperature of the vaporization chamber 19;
is a burner facing the gas injection nozzle 1.

Next, the operation will be explained. First, when performing combustion, electricity is started to be supplied to the heater 14, and at the same time, the electromagnetic solenoid 5 is energized, and the plunger 6 moves forward against the return spring 10.
The nozzle hole 2 is closed by the needle 4.

Then, by energizing the heater 14, the vaporization chamber 1
When the temperature of the fuel tank 9 reaches about 200° C., the liquid feed pump 22 is driven and the supply of liquid fuel from the fuel tank 12 to the vaporization chamber 19 is started. At the same time, the electromagnetic solenoid 5 is brought into a non-energized state. As a result, the plunger 6 is moved back by the return spring 10, closing the return valve seat 8, and the needle 4 is also moved back, so that the nozzle hole 2 is opened.

Therefore, the liquid fuel fed to the vaporization chamber 19 is heated by the heater 14, the outer cylinder 17, and the brass wire mesh 18, vaporizes, and becomes vapor, and then passes through the pores 20 and exits from the nozzle hole 2 of the gas injection nozzle 1. Burner 24
The fuel is injected with air, forms an air-fuel mixture in the burner 24, forms a flame in the burner head, and is combusted. During this combustion, the energization rate to the heater 14 is controlled by proportional control based on the temperature detection signal of the thermistor 23, and the temperature of the vaporization chamber 19 is kept between 250°C and 350°C.
It is maintained at around ℃.

To extinguish the fire from this combustion state, power is turned off to the heater 14 and liquid pump 22, and at the same time power is applied to the electromagnetic solenoid 5. This causes the nozzle hole 2 to be closed by the needle 4 and the return hole 7 to be closed. After being opened, the steam remaining in the gas injection nozzle 1 is returned to the fuel tank 12 through the return hole 7 and the return pipe 13. After a certain period of time has elapsed, the electromagnetic solenoid 5 is de-energized, the plunger 6 retreats, the nozzle hole 2 is opened, and the return hole 7 is closed.

In addition, when performing dry firing, as shown in FIG. 7, electricity is started to be applied to the heater 14 to raise the temperature of the vaporization chamber 19, and at the same time, electricity is applied to the electromagnetic solenoid 5 to close the nozzle hole 2. . The temperature of the vaporization chamber 19 is proportionally controlled based on the temperature detection signal from the thermistor 23, and the current flow rate to the heater 14 is controlled to maintain the temperature at about 500°C. Therefore, the tar adhering to the heater 14, outer cylinder 17, brass wire mesh 18, gas injection nozzle 1, and needle tube 3 is burned off. During this time, the electromagnetic solenoid 5 is maintained in an energized state, the nozzle hole 2 is closed, and after a certain period of time, the power supply to the heater 14 is stopped, and at the same time, the power supply to the electromagnetic solenoid 5 is also stopped, and the plunger 6 is moved to the return spring. 10, the nozzle hole 2 is no longer blocked by the needle 4.

[Problem that the invention attempts to solve]

Conventional vaporized liquid fuel combustion devices are constructed as described above, and as the needle is maintained in a state where the nozzle hole is blocked during empty firing, there is a risk that tar adhering to the inside of the nozzle may burn onto the needle, causing the needle to close. There were problems such as problems such as problems with operation, or needles that were malfunctioning due to tar adhering during combustion and did not recover even after dry firing.

This idea was made to solve these problems, and it is a vaporized liquid fuel combustion device that can improve the dry firing effect, extend the operating life of the needle, and improve tar durability. The purpose is to obtain.

[Means for solving problems]

In the vaporized liquid fuel combustion apparatus according to this invention, the needle is actively reciprocated a plurality of times by the needle control means during dry firing by the dry firing means.

[Effect]

The vaporized liquid fuel combustion device in this invention is
By actively reciprocating the needle a plurality of times during dry firing, the tar attached to the inside of the gas injection nozzle is cleaned, and the tar content is prevented from sticking to the needle, thereby improving the dry firing effect.

〔Example〕

FIG. 1 is an overall configuration diagram of an embodiment of a vaporized liquid fuel combustion apparatus according to this invention. As is clear from FIG. 1, this embodiment includes a gas injection nozzle 1 having a nozzle hole 2, a needle 4 for opening and closing the nozzle hole 2, and a heater 14, and a fuel tank 12.
a vaporizing chamber 19 that vaporizes liquid fuel supplied from the gas injection nozzle 1 and introduces it into the gas injection nozzle 1; and a dry heating means that burns tar adhering to the gas injection nozzle 1 and the vaporizing chamber 19 at a high temperature using a heater 14. 25, and a needle control means 26 which opens and closes the nozzle hole by reciprocating the needle a plurality of times when the drying means 25 is activated.

The mechanical structure of the vaporized liquid fuel combustion apparatus according to this invention is exactly the same as that of the conventional example shown in FIG. 6, so illustration and description thereof will be omitted.

FIG. 2 is a circuit diagram showing the electrical connections of the embodiment shown in FIG.
It has an output circuit 31. 32 is a start switch, 33 is a fire extinguishing switch, and 34 is an air-burning switch, the switch signals from these are input to the input circuit 30, and the input circuit 30 also receives a signal from a thermistor 23 that detects the temperature of the vaporization chamber 19. temperature detection signal is input. 35 is a heater drive circuit connected to the output circuit 31, which controls the heater 14 according to a heater control signal output from the output circuit 31.
Controls energization. 36 is a needle control circuit connected to the output circuit 31, and a driver 37
and a relay 38, an AC power supply 39 and a rectifier 40 whose normally open contact 38a is inserted into one connection line.
The output side of the rectifier 40 is connected to the electromagnetic solenoid 5 that drives the needle 4.

Next, the operation of the above embodiment will be explained with reference to FIGS. 3 to 5. 3 and 4 are flowcharts showing the empty firing processing program and timer interrupt processing program respectively stored in the memory 29 of the microcomputer 27, and FIG. 5 shows the vaporizing tube temperature and needle operation during empty firing. It is an operation explanatory diagram.

First, when the start switch 32 is turned on, the electromagnetic solenoid 5,
The liquid fuel is vaporized in the vaporization chamber 19 by controlling the heater 14 and the liquid pump 22, and introduced into the gas injection nozzle 1, and is supplied with air to the burner 24 from the nozzle hole 2 to be burned. Similarly, when the fire extinguishing switch 33 is turned on, the extinguishing control is performed in exactly the same way as in the conventional example to extinguish the fire.

On the other hand, when the dry roasting switch 34 is turned on, the switch signal is input to the input circuit 30, and the microcomputer 27 executes the dry roasting process shown in FIG.

That is, in step 41, a command value N for reciprocating the needle 4 is set to "1". Next, in step 42, the temperature detection value t from the thermistor 23 is read, and in step 43, it is determined whether t≧500°C. The determination in this case is to determine whether the temperature of the vaporizing tube 15 has reached the empty temperature, and at the start of the process, t<500.
℃, the process moves to step 44.

In step 44, a heater control signal is output to the heater drive circuit 35 to start energizing the heater 14.

Next, the process moves to step 45 to determine whether or not a predetermined time required for empty firing has elapsed, and since the process has just started, the process returns to step 42.

Then, by repeating steps 42 to 45, when the temperature of the vaporizing tube 17 reaches approximately 500°C, the process moves directly from step 43 to step 45, and the heater 14
When the temperature of the vaporizing tube 17 decreases due to this stopping of the electricity supply, the process moves from step 43 to step 44 again, and the electricity supply to the heater 14 is started, and eventually the temperature of the vaporizing tube 15 decreases to the temperature shown in FIG. The temperature is maintained at approximately 500°C, as shown in .

On the other hand, since the command value N is set to "1" in step 44, in the timer interrupt process shown in FIG.
1 to step 52, the count value T of the timer formed in a predetermined area of the memory 29 is counted up by "1", and then, in step 53, it is determined whether the count value of the timer is greater than or equal to a predetermined set value α. judge. The determination in this case is to set the time for which the electromagnetic solenoid 5 is to be in the energized state, and when T<α, the process moves to step 54 and the on-state solenoid control signal is output from the output circuit 31. Output. In this way, when the solenoid control signal is output, the relay 38 is energized by the driver 37, its normally open contact 38a is closed, and alternating current from the alternating current power supply 39 is supplied to the input side of the rectifier 40. Therefore, DC output can be obtained from the output side. Therefore, the electromagnetic solenoid 5 is energized and the plunger 6 is activated by the return spring 10.
The needle 4 moves forward against the nozzle hole 2.
is occluded.

Thereafter, when the count value of the timer becomes T=α, the process moves from step 53 to step 55.
It is determined whether the count value of the timer is greater than or equal to a predetermined set value β that is larger than the predetermined set value α. The determination in this case is to set the time period for which the electromagnetic solenoid 5 is in a non-energized state, and α≦T
<β, proceed to step 56,
After the solenoid control signal is turned off, the process returns to the empty firing processing program. In this way, when the solenoid control signal is turned off, the driver 37
The energization of the relay 38 is released, its normally open contact 39 is opened, and the energization of the electromagnetic solenoid 5 is stopped. Therefore, the plunger 6 is moved back by the return spring 10, the nozzle hole 2 is no longer blocked by the needle 4, and the nozzle hole 2 is opened.

Thereafter, when the count value T of the timer becomes T≧β, the process moves from step 55 to step 57, the count value T of the timer is reset to "0", and then the process returns to the emptying process program.

Therefore, in the next interrupt process, since T<α, the process moves from step 53 to step 54, the solenoid control signal is turned on, the electromagnetic solenoid 5 is energized again, and the nozzle is activated by the needle 4. Close hole 2.

Then, the opening/closing operation of the nozzle hole 2 by the needle 4 is continued until the needle drive command value N is cleared to "0".

Thereafter, when a predetermined period of time has elapsed in the dry firing process shown in FIG. 3, the process moves from step 45 to step 46, where the needle drive command value N is cleared to "0" and the dry firing process is ended.

As a result, the timer interrupt process shown in FIG. 4 ends immediately from step 51, and the electromagnetic solenoid 5 is maintained in a non-energized state.

As described above, the dry firing process shown in FIG. 3 is executed, the heater 14 is energized, and at the same time the needle 4 is reciprocated at a predetermined period by the timer interrupt process shown in FIG. is actively opened and closed as shown in FIG. Since it is smoothly extruded from the nozzle hole 2 in response to the operation, the emptying effect can be improved.

In the above embodiment, the case where the needle is moved back and forth at a certain constant period during dry firing is explained, but this is not limited to this, and the needle may be moved back and forth at a random period. It is sufficient if it is made to move back and forth.

[Effect of idea]

As explained above, this device is configured to open and close the nozzle hole by reciprocating the needle multiple times during dry firing, thereby preventing tar build-up on the needle and cleaning the gas injection nozzle. Since the dry firing efficiency can be improved, smooth operation of the needle can be guaranteed and a long-life vaporized liquid fuel combustion device can be obtained, which is effective.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of one embodiment of the vaporized liquid fuel combustion device according to this invention, Fig. 2 is a circuit diagram showing its electrical connections, Figs. 3 and 4 are flowcharts showing its operation, and Fig. 5 is a waveform diagram for explaining its operation, FIG. 6 is a sectional view showing a conventional vaporized liquid fuel combustion apparatus, and FIG. 7 is a waveform diagram for explaining its operation. In the figure, 1 is a gas injection nozzle, 2 is a nozzle hole, 4 is a needle, 5 is an electromagnetic solenoid, 12 is a fuel tank, 14 is a heater, 19 is a vaporization chamber, 23
24 is a thermistor, 24 is a burner, 25 is an air heating means, 26 is a needle control means, 27 is a microcomputer, 34 is an air heating switch, 37 is a driver, 38 is a relay, 39 is an AC power supply, and 40 is a rectifier. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A gas injection nozzle having a needle for opening and closing a nozzle hole, and a vaporization chamber having a built-in vaporization auxiliary tool to vaporize liquid fuel supplied from a fuel tank and introducing it into the gas injection nozzle, and the gas injection nozzle, In a vaporizing liquid fuel combustion device equipped with a drying means for dry burning tar attached to a vaporization chamber at high temperature, when the drying means is operated, the needle is reciprocated multiple times to open and close a nozzle hole. A vaporizing liquid fuel combustion device characterized by being provided with needle control means.