JPS61114010A - Evaporation type combustion device - Google Patents

Abstract

PURPOSE:To obtain an evaporation type combustion device having excellent resistance for tar and a long life by a method wherein a nozzle hole is closed by a needle when flame current has become smaller than specified value after stopping of a magnetic pump. CONSTITUTION:Ionic current of flame is detected by a flame rod 11 and an ionic current detecting means 22 and the flame becomes small by the stopping of the magnetic pump 2 upon extinguishing a fire, thereafter, the inoic current is compared by a comparing means 23 whether it become smaller than the specified value or not. In case of small value, the connducted electric current for a solenoid 14 is controlled by a needle control means 24 which receives a signal from a main control part 20, then, a nozzle 8 is closed by needle. According to this method, kerosine oil remaining in an evaporating chamber and the kerosine oil recovered from a return pipe become very small amount, and the amount of tar adhered, accumulated into the evaporating chamber also becomes small. Therefore, the evaporation type device having the excellent resistance for tar and the long life may be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Public Expenses for Industrial Use] This invention relates to a vaporization type combustion device that vaporizes and burns liquid fuel such as kerosene.

[Conventional technology]

A conventional vaporization type combustion apparatus will be explained with reference to FIG.

In the figure, 1 is an oil tank, 2 is an electromagnetic pump for supplying kerosene in the oil tank 1 to the vaporization chamber 4 inside the vaporizer 3, and 5 is a vaporization stabilizer 1.6 provided in the vaporization chamber 4. During combustion, the temperature inside the vaporization chamber 4 is kept constant by a control circuit (not shown) and a vaporizer thermistor 7 attached to the side wall of the vaporizer 3.

8 is a nozzle hole provided in the upper part of the vaporization chamber 4, 9 is a burner installed opposite to the nozzle hole 8, and above the burner is a spark plug 10 for igniting the vaporized gas and detecting the ionic current of the flame. A frame quadrilateral 11 is provided for this purpose.

12 is a needle with a needle-shaped tip for opening and closing the nozzle hole 8; 13 is a movable piece integrated with the needle 12; 14 is a solenoid for sliding the movable piece 13;
15 is a spring that pushes the movable piece 13 to the right in the figure when the solenoid 14 is not energized to open the nozzle hole 8, and 16 is a spring that communicates kerosene with the oil tank 1 when the nozzle hole 8 is open. Return valve 17 This is a return valve for preventing leakage to the collar, and is integrated with the movable piece 13.

When the solenoid 14 is energized, the movable piece 13 slides to the left in the figure against the spring 15, and the needle 12 reliably closes the nozzle hole 8, and the return valve 16 opens and remains in the vaporization chamber 4. The kerosene is collected into the oil tank 1 through a return pipe 17.

Next, the operation will be explained with reference to the time chart of FIG.

1 First, in order to vaporize kerosene, vaporize chamber 4
Since it is necessary to bring the temperature inside the chamber to a predetermined temperature (250 to 300 degrees Celsius), electricity is supplied to the vaporizer 6 to start the vaporizer 3, the vaporization chamber 4,
The vaporization stabilizer 5 is heated. During this preheating period, part of the kerosene adhering to the vaporization chamber 4 vaporizes as the temperature rises and leaks to the outside from the nozzle hole 8, producing a bad odor. It is closed at 12.

Next, when the temperature of the vaporization chamber 4 reaches a predetermined temperature and preheating is completed, the electromagnetic pump 2 is operated, and kerosene is supplied from the oil tank 1 to the vaporization chamber 4, where it is simultaneously heated and turned into vaporized gas.

At this time, the power supply to the solenoid 14 is stopped, the needle 12 slides and opens the nozzle hole 8, and vaporized gas is ejected from the nozzle hole 8, surrounding the primary air that acts as combustion air. and enters the burner 9 as a mixture.

An ignition plug 10 that starts discharging as soon as preheating is completed is attached to the upper part of the burner 9, and the air-fuel mixture is ignited by a spark during discharging. Flame ions detected by flame rod 11 after ignition 1) When the current exceeds a certain value, a control circuit (not shown) detects ignition and stops the discharge of spark plug 10.

During combustion operation, Tanabata 6 is the carburetor thermistor 7 and l11!
The temperature inside the vaporizing chamber 4 is controlled to be substantially constant by an Il&j circuit (not shown).

Next, when extinguishing the fire, when the operation switch etc. are turned off, the electromagnetic pump 2 is stopped and the supply of kerosene is interrupted, and the solenoid 14 is energized and the nozzle hole 8 is closed by the needle 12. Since the return valve 16 opens at the same time, most of the vaporized gas remaining in the vaporization chamber 4 passes through the gap around the needle 12 and the movable piece 13 and is condensed and liquefied. will be collected within. Further, since the power supply to the heater 6 is also stopped, the temperature inside the vaporization chamber 4 decreases, and a portion of the vaporized gas that has not been recovered and remains is also liquefied. If the solenoid 14 is de-energized and the nozzle hole 8 is opened after a period of time for the temperature in the vaporization chamber 4 to sufficiently decrease, there will be almost no vaporized gas in the vaporization chamber 4, and the nozzle will open. There is no risk of vaporized gas leaking from the hole 8 and creating a bad odor.

[Problem that the invention seeks to solve]

Conventional evaporative combustion devices are configured as described above, so when a fire is extinguished, the vaporizing chamber 4 is filled with vaporized gas and the nozzle hole 8 is blocked, causing the vaporized gas to condense and liquefy. However, the amount of kerosene remaining in the vaporization chamber 4 and the amount of kerosene recovered into the oil tank 1 from the return pipe 17 were large.

As is well known, kerosene that has been heated twice to high temperatures is easily oxidized and tar (carbide) is easily precipitated. There was a major problem in that as the amount increased, the vaporization of kerosene was inhibited and the combustion condition worsened.

This invention was made to solve the above-mentioned problems, and an object of the present invention is to provide a vaporization type combustion apparatus in which the amount of tar deposited inside the vaporization chamber is minimized.

[Means for solving problems]

In the vaporizing combustion device according to the present invention, when extinguishing a fire, after stopping the supply of kerosene by the electromagnetic pump, the ion current of the flame i
Comparison means for comparing f and a preset reference value 10;
A needle control means is provided which closes the nozzle hole with a needle when the ionic current is smaller than a reference value as a result of the determination by the comparison means.

[Effect]

In this invention, when extinguishing a fire, the electromagnetic pump stops, the flame becomes smaller, and the comparison means compares whether or not the ion current becomes smaller than a reference value, and when the flame becomes smaller, the needle controls the needle to close the nozzle hole. do.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings. FIG. 1 is a schematic diagram of a vaporization type combustion apparatus according to the present invention. Note that the parts with the same reference numerals as in FIG. 6 are the same parts, so the explanation will be omitted.

In the figure, 20 is a main control unit that controls most of the operations of the combustion device, 21 is an electromagnetic pump drive circuit that inputs signals from the main control unit 20 to drive the electromagnetic pump 2, and 22 is a flame rod that flows from the flame rod 11. 23 is a comparison means for comparing the detection value if detected by the ion current detection means 22 with a preset reference value io, and the comparison result is sent to the main control unit. 20
is input. Reference numeral 24 denotes a needle control means that receives a signal from the main control section 20 and controls energization of the solenoid 14 to open and close the nozzle hole 8 with the needle 12.

FIG. 2 is a circuit diagram showing the electrical connections of the embodiment of FIG. 1. In the figure, 25 is the main control unit 20, electromagnetic pump drive diagram @2
1. A microcomputer in charge of most of the operations of the comparison means 23, needle control means 24, etc., and the CP02
B, a memory 27, an input port $28, and an output circuit 29. 30 is a room temperature thermistor that detects the indoor temperature; 31
is a variable resistor for setting the indoor temperature, and 32 and 35 are resistors connected in series with 30 and 31. The ion current detection means 22 connects the frame rod 11 and the bar.
A DC voltage is applied to the flame 34 between the henna 9, the ionic current of the flame is detected through the resistor 35, and the value is inputted to the A/D converter 37 through the analog multiplexer 36 and converted into a digital signal. This is input to the input circuit 28. The detection outputs of the room temperature thermistor 30 and the movable resistor 31 are also input to the input circuit 28 in the same manner. Further, 38 is an operation switch, 39 is a resistor connected in series with the operation switch 38, and the ON-OFF state of the operation switch 38 is also connected to the input circuit 28.
40 is a diode bridge that performs full-wave rectification of the commercial power supply 41, 42 is a relay that turns on and off power to the Lt solenoid 14, and 43 and 44 are transistors that control the opening and closing of the relay 42 by signals from the output circuit 29. It is a resistor and, together with the relay 42, is part of the needle control means 24.

45 and 46 are transistors and resistors that amplify the signal from the output circuit 29 to operate the electromagnetic pump 2, which are part of the electromagnetic pump drive circuit 21, and are connected to the ON-
The operating speed of the electromagnetic pump 2 is adjusted according to the OFF period to change the amount of kerosene supplied.

Next, the operation of the embodiment will be explained with reference to the cross-sectional views of FIGS. 3 to 5 and 6. FIG. 3 is a flowchart showing a part of the combustion control program stored in the memory 27 of the micro combinator 25, and FIGS.
FIG. 3 is an explanatory diagram of the operation of No. 3.

First, when the operation switch 38 is turned on, the ON signal is input to the input circuit 28, and the preheating process 46 shown in FIG. 3 starts. After the preheating process 4146 is completed, the ignition process 47
, and then the combustion process 48, but since the operation of each process is the same as in the conventional example, the explanation will be omitted. In the combustion process 48, the room temperature is constantly detected by the room temperature thermistor 30, and is input from the input circuit 28 and stored in the memory 27.
stored within. On the other hand, the set temperature set by the variable resistor $31 is also stored in the memory 27 in the same way, and in step 49, the room temperature and the set temperature are compared and determined. Strong combustion occurs, and the electromagnetic pump 2 operates at high speed, increasing the amount of kerosene supplied and generating a large amount of heat. When the room temperature rises and becomes room temperature≧set temperature, weak combustion occurs in step 51, the electromagnetic pump 2 operates at low speed, and the amount of kerosene supplied decreases. In step 52, the ion current if is measured by the frame wood 11 and the ion current detection means z2, and during combustion, steps 48 to 53 are repeatedly executed to constantly measure the ion current if of the room temperature and the flame.

Next, when extinguishing the fire, turn off the operation switch 38.

The OFF signal of the operation switch 38 is input to the input circuit 28, a determination is made in step 53, a fire extinguishing operation is performed in step 54, and the electromagnetic pump 2 is stopped. At this time, as shown in FIG. 4, the ion current if gradually decreases with time after the electromagnetic pump 2 is stopped. Here, memory 27
Set a reference value called io in advance in step 5.
In step 5, the CPU 26 compares if and to. During strong twist firing in FIG. 4, the ionic current if decreases;
When the point T is reached, the solenoid 14 is energized in step 56. The nozzle hole 8 is closed by the needle 12 when the solenoid 14 is energized, but the nozzle hole 8 is closed after the amount of vaporized gas ejected from the nozzle hole 8 decreases and the ionic current if decreases. Almost no vaporized gas remains in the vaporization chamber 4, and the amount of kerosene recovered from the return pipe 17 into the oil tank 1 also becomes very small. Next, in the case of weak combustion, the ionic current during combustion is 1
t is smaller than during strong twist firing, and is i f (i o), so when extinguishing a fire, the solenoid 14 is energized at the same time as the electromagnetic pump 2 is stopped, and the nozzle hole 8 is blocked. Since the amount of kerosene supplied by the pump 2 is small, even if the nozzle hole 8 is closed at the same time as the electromagnetic pump 2 is stopped, only a small amount of vaporized gas remains in the vaporization chamber 4 (there is no problem).

FIG. 5 shows an example of operation when the reference value to is determined based on the value of the ionic current if immediately before extinguishing.

During combustion, the latest ion current if value is always stored in the memory 27 in step 52, and when the knee extinguishing operation in step 54 is performed by turning the operation switch 38 OFF, the value of the ion current if immediately before the operation switch 38 is turned OFF. Let the detected value of be ife, and multiply if@ by a constant value smaller than 1 to get the reference value i.

This io is compared with the gradually decreasing ion current if in step 55, and when iE≦to, the solenoid 14 is energized in step 56 to close the nozzle hole 8. In Fig. 5, the ionic current if is different between strong twist firing and weak combustion, so for example 1, such as 0.75.
If ife is multiplied by a smaller constant value, ioh will be obtained during strong twist firing.
, ioj during weak combustion.

As a result, the point at which the solenoid 14 is energized is T for strong twist firing and T for weak combustion, and the amount of combustion just before extinguishing,
That is, depending on the amount of vaporized gas supplied from the nozzle hole 8, the time from when the operation switch 38 is turned off to when the nozzle hole 8 is closed changes.

Therefore, depending on the combustion state immediately before extinguishing, the nozzle hole 8
By setting the value multiplied by ife to an appropriate value, the vaporized gas in the vaporization chamber 4 can be sufficiently discharged from the nozzle hole 8 after the electromagnetic pump 2 has stopped, in any combustion state. In addition, the nozzle hole 8 can be closed just before the jetting force of the vaporized gas weakens, extinguishes the gas, and generates an odor. 1, the amount of kerosene recovered can be extremely reduced.

〔Effect of the invention〕

As described above, according to the present invention, after stopping the electromagnetic pump,
A needle control means is provided that closes the nozzle hole with a needle after the ionic current of the flame decreases and becomes smaller than a preset reference value, so that the kerosene remaining in the vaporization chamber and the kerosene recovered from the return pipe are Since the amount of tar adhering and accumulating in the vaporization chamber can be extremely small, it is possible to obtain a vaporization type combustion device with excellent tar resistance and a long life.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of a vaporization combustion apparatus according to an embodiment of the present invention, Fig. 2 is a circuit diagram showing its electrical connections, Fig. 3 is a flowchart showing its operation, Figs. 4 and 5. 6 is a sectional view of a conventional vaporization type combustion apparatus, and FIG. 1 is a time diagram for explaining the operation of the conventional example. In the figure, 1 is an oil tank, 2 is an electromagnetic pump, 4 is a vaporization chamber, and 8
9 is a nozzle hole, 9 is a burner, 12 is a needle, 22 is an ion current detection means, 23 is a comparison means, and 24 is a needle control means. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa (2 others) Fig. 1 2: Den, ra, $'shi2' Skono2lulu heeI: be-t-tt: yb-co, I-0. Kohei εi Yaheshi Kō, 6" r hole, return, dormitory, Tenu

Claims (2)

[Claims] (1) In addition to being equipped with a needle for opening and closing the nozzle hole, liquid fuel is supplied from the fuel tank into the vaporization chamber by a pump, and the vaporized gas is guided to the nozzle hole and combusted by a burner. ion current detection means for detecting the ionic current of the ion current, a means for comparing the detected value if of the ion current with a preset reference value io, and after stopping the supply of liquid fuel by the pump during digestion, A vaporization type combustion apparatus characterized in that a needle control means is provided for closing a nozzle hole when the comparison result of the comparison means becomes if<io. (2) The vaporization combustion device according to claim (1), wherein the value of the reference value io is the value obtained by multiplying the detected ion current value if immediately before digestion by a constant value smaller than 1. .