JPH0318833Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field> The present invention relates to a liquid fuel vaporizing combustor, and particularly to control of a cleaning operation for incinerating deposits within the vaporizer.

<Prior art> In a vaporization combustor that gasifies liquid fuel in a vaporizer and burns it in a burner, vaporization occurs when poor quality fuel (altered kerosene, etc.) is used or even normal kerosene is burned for a long time. Tar adhesion and accumulation inside the vessel, vaporizing element, nozzle, etc. caused problems such as changes in combustion conditions and a decrease in calorific value.

To eliminate this problem, simply clean the vaporizer. However, immediately after cleaning starts, the temperature of the vaporizer has not risen sufficiently, so unhardened liquid tar flows out from the vaporization element to the nozzle due to the air pressure of the air pumped by the pump, and adheres to the inner surface of the nozzle. Sometimes, it flowed out from the nozzle and adhered to the vicinity of the nozzle hole, causing the nozzle to lose its roundness.

For this reason, in the past, the vaporizer was first heated to a high temperature to harden the tar, and then the pump was operated to forcefully send air to prevent liquid tar from flowing out and adhering to the nozzle hole or the like.

4 and 5 are time charts in the conventional technology.

In Figures 4 and 5, the heater is for heating the carburetor, and the pump is for pumping the fuel in the fuel tank to the carburetor.During cleaning operation, it has the function of emptying the fuel tank and pumping air. have The solenoid also opens and closes a return valve installed in the return path from the carburetor to the fuel tank.
It is also used to drive the cleaning rod that opens and closes the nozzle of the vaporizer. This solenoid is configured to close the nozzle and open the return valve when energized, and to open the nozzle and close the return valve when power is cut off.
In Figure 4, since pump operation and heater operation start at the same time, unhardened liquid tar inside the vaporizer flows out and adheres to the vicinity of the nozzle due to the air pressure pumped by the pump, causing the roundness of the nozzle to deteriorate. I had something to lose.

FIG. 5 shows a conventional method for solving this problem. In Fig. 5, the heater is first energized, and after the vaporizer reaches a high temperature, the pump is activated, and the cleaning rod that opens and closes the nozzle is moved back to open the nozzle. The remaining fuel was vaporized in the high-temperature vaporizer, creating a large amount of white smoke that spewed out from the nozzle.

In other words, since the pump is operated after the carburetor is heated to a high temperature, the remaining fuel inside the pump and oil pipe is pumped to the carburetor, and is rapidly vaporized in the high-temperature carburetor, producing a large amount of white smoke. There was a problem with spraying from the nozzle.

<Objective> The present invention aims to provide a liquid fuel vaporizing combustor that can prevent the generation of a large amount of white smoke due to vaporization of residual liquid fuel during cleaning of the vaporizer.

<Example> An example of the present invention will be described below with reference to FIGS. 1 to 3. The liquid fuel vaporizing combustor according to the present invention includes a pump for pressure-feeding liquid fuel in a fuel tank. 1, a vaporizer 2 for vaporizing the liquid fuel pumped by the pump 1 into vaporized fuel, a nozzle 4 for spouting the vaporized fuel to the burner 3, and a cleaning rod for opening and closing the nozzle 4. 5 and
A drive unit 6 for opening and closing the cleaning rod 5, a return passage for discharging the liquid fuel in the vaporizer 2, a return valve 8 for opening and closing the return passage 7, and Heating means 9 for heating, and temperature detector 10 for detecting the temperature of the vaporizer 2
and a control device 11 that controls the pump 1, the drive section 6, the return valve 8, and the heating means 9, and the control device 11 is configured to increase the temperature of the vaporizer to a higher temperature than during normal combustion. This is to control the cleaning operation that burns the deposits inside the carburetor.When the cleaning operation starts, the pump is driven to forcefully send air and liquid fuel remaining in the vaporizer is discharged from the return path. a pump control means that stops the pump after a predetermined period of time has elapsed, and then restarts the pump to pump air when the vaporizer reaches a set temperature; a drive unit control means that opens the cleaning rod when the set temperature is reached; a return valve control means that opens the return valve when the cleaning operation starts and closes the return valve when the vaporizer reaches the set temperature; and heating control means for driving and controlling the heating means after a predetermined period of time has elapsed from the start of the cleaning operation.

Note that the predetermined time period refers to the time period during which the liquid fuel remaining in the vaporizer 2 is discharged from the return path 7.

The pump 1 is attached to the upper part of a fuel tank 12, and the pump 1 and the carburetor 2 are connected via an oil pipe 13.
consists of a vaporizer main body 2a and a heat recovery body 2b that is integrally formed on the upper part of the main body 2a and whose tip is located above the burner 3. Elements are included. Further, the heating means 9 comprises a heater attached to the outer circumferential wall of the vaporizer 2, and the heater 9 is energized and controlled by a temperature signal from the temperature detector 10, such as the thermistor, attached to the outer circumferential wall of the vaporizer 2. Ru. The return path 7 is a return pipe 1 that is formed at a position behind the nozzle 4 of the carburetor 2 and returns the liquid fuel in the return path 7 to the fuel tank 12.
4 is connected in communication. The return valve 8 is a solenoid valve interposed in the return path 7, and a drive unit 6 that drives the cleaning rod 5 using the solenoid of the solenoid valve is configured. That is, the integrated solenoid 8A, which drives the return valve 8 and constitutes the drive section 6 of the cleaning rod 5, is configured to close the cleaning rod 5 and open the return valve 8 when it is energized.

The solenoid shown in FIG. 1 is the integrated solenoid 8A.

The control device 11 is composed of a general one-chip microcomputer, and has data inside.
It has a RAM, a program ROM, an ALU, and a timer 15, and as shown in FIG. and an output terminal for outputting a control signal.

FIG. 1 is a time chart according to the present invention.
First, when starting cleaning, the fuel tank is emptied so that air can be sent from the pump 1.
Then, at the same time as the cleaning starts, the pump 1, the drive unit 6, and the solenoid 8A of the return valve 8 are energized, and the liquid fuel remaining in the pump 1, the oil supply pipe 13, and the vaporizer 2 is removed by the air pressure generated by the operation of the pump 1. The fuel is returned to the fuel tank 12 through the pipe 14 from the return valve 8, which is opened by energizing the solenoid 8A. Next, the pump 1 is stopped at time t1 by the timer 15, which has been counting since the start of cleaning, and at the same time, the heater 9 is energized to heat the vaporizer 2. and temperature sensor 1
The vaporizer temperature detected at 0 is the set temperature (approximately 400℃)
When the time is reached (time tz in FIG. 1), the operation of the pump 1 is restarted by a signal from the control device 11, and at the same time, the nozzle 4 is opened by the cleaning rod 5. This results in
The hardened tar in the vaporizer can be burnt off and jetted out from the nozzle using compressed air from the pump 1. At this time, pump 1, oil pipe 13
Also, since the residual oil in the vaporizer has already been discharged into the fuel tank 12, the residual oil will not be sent into the high-temperature vaporizer 2, and a large amount of white smoke will not be generated.

Note that the operation of the pump 1 is started by the control device 11 instead of the temperature detector 10 detecting the vaporizer temperature.
This may also be done by a timer 15 built into the device. That is, the timer 15 counts from the start of cleaning to determine the set time t2, that is, the time when the vaporizer temperature reaches the set temperature (approximately 400°C or higher) as an experimental value, and at that time, the timer 15 starts the control device. 4, a signal may be output to restart the pump operation.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

<Effects> As is clear from the above explanation, the present invention includes a pump for pressure-feeding liquid fuel in a fuel tank,
A vaporizer for vaporizing the liquid fuel pumped by the pump into vaporized fuel, a nozzle for ejecting the vaporized fuel to a burner, a cleaning rod for opening and closing the nozzle, and a drive for opening and closing the cleaning rod. a drive unit for discharging the liquid fuel in the vaporizer, a return passage for discharging the liquid fuel in the vaporizer, a return valve for opening and closing the return passage, and a heating means for heating the vaporizer; Cleaning in which the liquid level of the liquid fuel in the tank is lowered or emptied, only air is sent from the pump to the vaporizer, and the temperature of the vaporizer is raised to a higher temperature than during normal combustion to incinerate deposits inside the vaporizer. A liquid fuel vaporization type combustor that can be operated is provided with a control device that controls the pump, the drive section, the return valve, and the heating means, and the control device sends a drive signal to the pump at the start of the cleaning operation. It has a function of outputting a heating signal to the heating means after a predetermined period of time has elapsed after outputting an opening signal to the output and return path and outputting a nozzle closing signal to the drive section. Therefore,
According to the present invention, when cleaning the carburetor, before raising the carburetor temperature, the pump is operated to discharge the residual fuel in the carburetor through the return path, and then the carburetor is heated to a high temperature, so that a large amount of residual fuel is vaporized. It has excellent effects such as being able to reduce the generation of white smoke.

[Brief explanation of the drawing]

Fig. 1 is a time chart during cleaning of the carburetor showing an embodiment of the present invention, Fig. 2 is a block diagram of the main parts of the vaporizer, Fig. 3 is a block diagram of the control device, and Fig. 4 is a diagram of the main parts of the carburetor. Conventional cleaning time chart. FIG. 5 is another conventional cleaning time chart. 1... pump, 2... vaporizer, 3... burner,
4... Nozzle, 5... Cleaning rod, 6... Drive unit, 7
Return path, 8...Return valve, 9...Heating means, 10...
...Temperature detector, 11...Control device.

Claims (1)

[Scope of claim for utility model registration] A pump for pumping liquid fuel in a fuel tank, a vaporizer for vaporizing the liquid fuel pumped by the pump into vaporized fuel, and sending the vaporized fuel to a burner. a nozzle for ejecting; a cleaning rod for opening and closing the nozzle; a drive unit for driving the cleaning rod to open and close; a return path for discharging liquid fuel in the vaporizer; and a return path for opening and closing the return path. a return valve for heating the vaporizer; and a heating means for heating the vaporizer; the liquid level of the liquid fuel in the fuel tank is lowered or emptied, and only air is force-fed from the pump to the vaporizer;
A liquid fuel vaporization type combustor capable of performing a cleaning operation in which the temperature of the vaporizer is set higher than that during normal combustion to incinerate deposits in the vaporizer, the pump, the drive unit, the return valve, and the heating A control device is provided for controlling the means, and the control device outputs a drive signal to the pump at the start of the cleaning operation, outputs an open signal to the return path, and outputs a nozzle close signal to the drive section, and then outputs a nozzle close signal to the drive section, and then outputs a nozzle close signal to the drive section. A liquid fuel vaporizing combustor, characterized in that it has a function of outputting a heating signal to the heating means after a lapse of time.