JPS6321091B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vaporizing oil combustor in which oil is vaporized in advance in a vaporizer by heating and then supplied to a burner through a nozzle for combustion. It was made sure.

First, a Bunsen gasification combustor, which is a conventional gasification oil combustor, will be explained with reference to FIGS. 1 and 2.

Reference numeral 1 designates a brass vaporizer main body forming a vaporization chamber 2. A gas injection nozzle 4 having a nozzle hole 3 is removably screwed onto the upper part of the vaporizer main body 1, and connection parts 5 and 6 on the lower side walls thereof are screwed. An oil pipe 8 communicating with the oil pump 7 and a return pipe 10 communicating with a normally open solenoid valve 9 which is closed when energized are connected. Reference numeral 11 denotes a cap that is detachably attached to the lower end opening of the carburetor main body 1.

12 is the vaporization chamber 2 from the lower end opening of the vaporizer main body 1.
It is a cylindrical brass vaporization aid that is inserted into the interior, and consists of an upper cylindrical part 12a and a lower cylindrical part 12b, the upper end of which abuts against the flange 13, and the lower end of which is the lower end opening of the vaporizer main body 1. Make it slightly more protruding,
This serves as a clue when taking out the vaporization aid 12. 14 is a recess formed in the lower cylindrical portion 12b, and a spring 15 is housed therein to constantly urge the vaporization aid 12 upward. 16 is the lower end of the upper cylindrical part 12a (i.e., the lower cylindrical part 12b
The inside and outside of the cylindrical part 12a are communicated through a plurality of holes drilled near the connecting part with the cylindrical part 12a. 17 is a vaporization stabilizing material such as foamed metal or sintered metal inserted into the upper cylindrical part 12a of the auxiliary tool 12;
2 and can be taken out from inside the vaporization chamber 2.

A heater 18 is attached closely to the side wall of the carburetor main body 1, is constantly pressed against the carburetor main body 1 side by a spring 19, and the outside thereof is covered with a cover 20. During normal combustion, the heater 18 controls the temperature inside the vaporizing chamber 2 by means of a temperature sensing element 21 (positive temperature coefficient thermistor) and an electronic control circuit 22.
The temperature is controlled at 240-280℃. Note that this is actually the temperature of the outer wall of the vaporizer. Note that 23 is a fuel tank and 24 is a burner.

Figure 2 is an electrical circuit diagram of the vaporizing oil combustor, and the heater 18 is controlled by an electronic control circuit 22.
The heater 18 and the relay switch 25 are connected in series to a normally closed relay switch 25 that is turned on and off, and the series circuit of the heater 18 and the relay switch 25 is connected in parallel to the series circuit of the solenoid valve 9 and the normally open relay switch 26. The relay switch 26 is closed by the electronic control circuit 22 when the temperature inside the vaporization chamber 2 reaches a predetermined temperature (240 to 280 DEG C.).

Here, the operation of the vaporizing oil combustor will be explained. First, when performing normal combustion, turn on the main switch 28 and turn on the switch 27.
When turned on, the oil feed pump 7 is driven and the heater 18 is energized to heat the carburetor main body 1.

Initially, since the temperature of the carburetor main body 1 is low, the relay switch 26 is in the OFF state and the solenoid valve 9 is opened. Therefore, the kerosene sucked up from the fuel tank 23 by the drive of the oil pump 7 enters the carburetor body 1 through the oil pipe 8 (the inner wall of the carburetor body 1 and the outer wall of the vaporization aid 12 from the return pipe 10 to the solenoid valve 9
A circulation path is formed through which it returns to the combustion tank 23.

When the temperature of the vaporizer main body 1 reaches a predetermined temperature (240°C to 280°C) by energizing the heater 18, the resistance value of the temperature sensing element 21 changes rapidly and the electronic control circuit 22 is activated. Relay switch 26 is closed. Therefore, the electromagnetic valve 9 is energized, the return passage is cut off, and the liquid level of the kerosene that has flowed into the carburetor body 1 gradually rises. And kerosene is auxiliary tool 1
penetrates into the vaporization stabilizer 17 through the small holes 16 of 2;
vaporize here. The vaporization temperature at this time is 240-280℃
By controlling ON/OFF of the relay switch 25 by the electronic control circuit 22, the energization time to the heater 18 is controlled, and the temperature in the vaporization chamber 2 is maintained at all times.
Maintained at 240-280℃.

In this way, the vaporized gas vaporized in the vaporization chamber 2 is supplied into the burner 24 through the nozzle hole 3 of the gas injection nozzle 4, and normal combustion is performed on the burner 24.

Next, details of the circuit shown in FIG. 2 will be further explained using FIG. 3. In FIG. 3, 21 is a positive characteristic thermistor, which controls the temperature of the vaporizer 1 to be constant. SW1 and SW2 are integrated power switches, and SW1 is an automatic release switch.
X ₁ and Y ₂ are power transformers for electronic circuits, T is a timer that controls combustion start time and combustion end time,
RY ₁ and RY ₂ are magnetic relays, PT is a pulse transformer, D is a diode, C is a capacitor,
R ₁ , R ₂ ... are resistors, Q ₁ , Q ₂ ... are transistors,
IC _1-1 to IC _1-4 are comparators, TS is anti-shock switch, G is ground terminal, FL is frame rod,
LED is a light emitting diode.

[Explanation of circuit operation]

[1-1] First, when switches SW ₁ and SW ₂ (corresponding to Fig. 2 28) are turned on (at this time, SW ₂ is only turned on momentarily), the primary side of the transformer
At the same time that voltage is applied to X ₁ and Y ₂ , voltage is also generated on the secondary side, and Q ₁ is generated through coils R ₁₈ , D ₇ , and R ₈ of RY _2.
is turned ON, and as a result, relay RY ₁ (corresponding to Fig. 2 27) maintains its self-holding even when operation SW ₂ is turned OFF, and power lamp LED 1 lights up.

[1-2] If the timer T is in the "continuous" or "time up" state, the pump 7 is energized and simultaneously the photocoupler PC1 is energized through D ₄ , R ₂ , and R ₃ .

[1-3] The light-receiving side transistor of PC1 is ON
Therefore, the transistor Q ₂ is connected through R ₅ , R ₉ , R ₁₀
Since the base voltage of is applied and Q ₂ turns ON, voltage is applied to comparator IC _1-1 .

[1-4] Since the temperature of the positive temperature coefficient thermistor 21 is low, its resistance is low, and the output of IC _1-1 is "low", so transistor Q ₆ is turned off.

[1-5] (Preheating) A full-wave rectified base current flows through transistor _Q7 through _R44 , and at the point where the current is zero, _Q7 is OFF, so _R43 ,
Charged to C ₁₃ through R ₄₆ .

When Q ₈ turns ON, the charge stored in C ₁₃ is discharged to the bases of transistors Q ₈ and Q ₄ , Q ₈ and Q ₄ turn ON for a moment, and current flows through the coil of pulse transformer PT, causing triac TR (see Figure 2). (equivalent to 25)
Turn on. Note that _Q8 turns off when _Q7 turns on. Zero-cross triggered triage
Heater 18 is turned on by TR.

[1-6] When the vaporizer 1 is heated by the heater 18, the resistance of the positive temperature coefficient thermistor 21 attached to the vaporizer increases and the comparator
The output of IC _1-1 is reversed from "low" to "high".

As a result, the transistor _Q6 is turned on, and the pulse current to the pulse transformer TR is turned off, which turns off the triax TR, so that the heater 18 is no longer energized.
It becomes OFF.

[1-7] (Ignition operation) The positive input of IC _1-2 is
Since it enters through R ₁₆ , D ₈ , and C ₆ , the output of IC _1-2 is inverted from "low" to "high" and transistor Q ₃ is inverted.
ON and relay RY ₂ (corresponding to 26 in Figure 2) is ON.
becomes. When RY ₂ turns ON, the igniter IGN, convection blower FM, and solenoid valve 9 are energized.

[1-8] Since RY ₂ turns on, the self-holding signal from R ₁₈ and D ₇ disappears, but as mentioned in [1-3], when transistor Q ₂ turns on, the electronic circuit 21
Since voltage is applied to the entire circuit, a holding signal flows from IC _1-4 through D ₁₂ and R ₈ to keep Q ₁ ON and RY ₁
's self-preservation is sustained.

[1-9] When the vaporized gas from the vaporizer 1 is ignited by the discharge spark from the igniter IGN, the flame resistance of the flame rod FL decreases, and the voltage at the negative terminal of the comparator IC _1-3 decreases, causing the voltage at the negative terminal of the comparator IC _1-3 to decrease.
The output changes from "low" to "high." At this time Q ₅
is turned on and LED ₂ lights up. Also R ₃₄ , D ₁₀ ,
A hold signal is output to the base of Q ₁ through R ₈ .

[1-10] (Ignition judgment) When the output of IC _1-2 changes to "high" and a certain period of time has passed (after preheating is completed),
The potential of C ₁₁ increases due to the output from IC _1-2 .
The output of IC _1-4 is reversed from "high" to "low" and R ₄₁ ,
The holding signals from D ₁₂ and R ₈ disappear. At this time
When there is no holding signal from IC _1-3 , Q ₁ turns OFF.
RY ₁ also turns OFF, releases self-holding, and stops operation. In other words, if the igniter IGN does not ignite even after discharging for a certain period of time, operation will be automatically stopped.

[1-11] (Temperature control) After starting combustion, the negative characteristic thermistor 21 causes the output of the comparator IC _1-1 to repeat "high" ← → "low", and as a result, the heater 18 performs ON-OFF operation. conduct,
Keep vaporizer 1 at 240°C to 280°C. Furthermore, at this time
Even if the output of IC _1-1 becomes "low", IC _1-2 remains "high" due to the discharge charge from C _6. If no charge is supplied from IC _1-1 even after a certain period of time,
Turn off.

In the above-mentioned oil combustor, the control temperature of the vaporization chamber 2 is set at a temperature (240 to 280 degrees ) is set. Therefore, ignition is performed after reaching the above-mentioned control temperature, which is the temperature for optimal combustion, but at this time, the pressure in the vaporization chamber is high, and this high-pressure vaporized gas is injected from the nozzle, so the air-fuel ratio at the burner changes. The disadvantage was that it was small and very difficult to ignite, and it took a long time to ignite.

The present invention was developed to eliminate these drawbacks, and by igniting at a temperature lower than the optimum combustion temperature, ignition is ensured and speeded up. That is, the present invention focuses on the fact that even in the above-mentioned vaporized oil combustor, ignition is easier at a temperature that is lower than the conventional optimum combustion temperature (for example, 150° to 230°). Ignition is ensured by performing two-stage temperature control that provides a difference between temperature and temperature control during combustion.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a circuit diagram of a main part of the present invention, which corresponds to the circuit section 30 surrounded by a dashed line in FIG. 3, and the same parts as in FIG. 3 are denoted by the same reference numerals.
In Figure 4, PTC2 is a newly added positive temperature coefficient thermistor, which is also installed on the outer wall of the carburetor body 1, and whose temperature is lower than the set temperature of PTC1 (150℃).
~230℃). Switch SW _A ,
SW _B is a dry firing instruction switch which will be described later.

The operation in FIG. 3 when FIG. 4 is applied is the same from [1-1] to [1-5] described above, but the operation after [1-6] is different.

That is, when the vaporizer 1 is heated by the heater 18 and its outer wall reaches, for example, 200°C, the resistance value of the positive temperature coefficient thermistor increases, and the comparator IC _1-2
The output of is reversed from "low" to "high". This reversal turns on transistor _Q3 and turns on relay _RY2 .
It becomes ON. When RY ₂ turns ON, the igniter IGN, convection blower FM, and solenoid valve 9 are energized. Since RY ₂ turns on, the self-holding signal from R ₁₈ and D ₇ disappears, but as mentioned in [1-3], when transistor Q ₂ turns on, voltage is applied to the entire electronic circuit 22, so IC _1-4 The holding signal flows through D ₁₂ and R ₈ , turning Q ₁ ON and connecting the self-holding of RY ₁ .

During this time, the kerosene fed to the vaporizer 1 by the pump 7 is vaporized in the vaporization chamber 2, although the pressure is not as high as in the middle of combustion, and is gradually supplied to the burner 24 through the nozzle hole 3. Even gas vaporized at such a low temperature is sufficiently ignited and combusted by the discharge spark from the igniter IGN. Note that low-pressure gas does not cause lift and is easier to ignite. That is, low-pressure gas has a larger air-fuel ratio in the burner and is much easier to ignite. When the vaporized gas is ignited, the flame resistance of the flame rod FL decreases and the comparator
The voltage at the negative terminal of IC _1-3 decreases, and the output of IC _1-3 changes from "low" to "high." At this time, _Q5 is turned ON and LED ₂ lights up. A holding signal is also output to the base of _Q1 through _R34 , _D10 , and _R8 .

The output of IC _1-2 changes to "high" (after preheating is completed)
After a certain period of time, the potential of C increases due to the output from IC _1-2 , and the output from IC _1-4 becomes "low" rather than "high".
, and the holding signals from R ₄₁ , D ₁₂ , and R ₈ disappear. At this time, if there is no holding signal from IC _1-3 , Q ₁ is
When it turns OFF, RY ₁ also turns OFF, releasing self-holding and stopping operation. In other words, if the igniter IGN does not ignite even after discharging for a certain period of time, operation will be automatically stopped.

Now, when ignition occurs and combustion starts, the vaporizer body 1 is rapidly heated by the combustion heat and the heat of the heater 18, and when its outer wall reaches, for example, 250°C, the comparator body 1 is heated by the action of the positive temperature coefficient thermistor 21 (PCT1). IC _1-1 output goes from “low” to “high”
to be reversed. As a result, the transistor _Q6 is turned on, and the pulse current to the pulse transformer TR is turned off, turning off the triac TR, and therefore the power to the heater 18 is turned off. After starting combustion, the comparator is activated by the positive thermistor 21.
The output of IC _1-1 repeats "high" ← → "low" and as a result, heater 18 performs ON-OFF operation to maintain vaporizer 1 at 240°C to 280°C.

In the above-mentioned operation, the time required from energization to ignition is about 1 minute, making the preheating time extremely short. Note that during the period from ignition to when the carburetor 1 reaches steady combustion, there is a slightly higher amount of tar generated than in the optimal combustion state, but this is an extremely short period of time, so there is no effect of accelerating ignition. rare.

In the vaporization type combustor mentioned above, when kerosene is vaporized in the vaporization chamber 2, the vaporization temperature (approximately 150℃ to 280℃
℃), it gradually turns into tar due to polymerization of molecules or minute residues (impurities), etc., and tar (charcoal) gradually adheres to the vaporization chamber and vaporization stabilizer as the combustion time progresses. Although the amount of tar varies depending on the temperature of the vaporizer, the method of vaporizing the kerosene, and the temperature rise of the kerosene, the generation of tar is unavoidable.

Therefore, if the tar adheres to and accumulates in the vaporization chamber 1 and the vaporization stabilizer 17, the vaporization passage will become clogged and the amount of vaporized gas will decrease, resulting in poor combustion such as a decrease in the amount of combustion, and eventually the device will become unusable. There is a drawback that. Therefore, in the present invention, the tar attached to the vaporization chamber and the vaporization stabilizing material is removed by dry firing at a temperature of 450 to 500C, which is higher than the normal vaporization temperature.

[About dry firing method]

In Fig. 4, positive temperature coefficient thermistors PTC1,
Switches SW _A and SW _B that short-circuit PTC2, respectively
is the dry firing instruction switch. In the case of this circuit, by operating SW _A and SW _B for dry heating, dry heating can be performed immediately before or even during combustion. Sunawato, Switch SW _A ,
When SW _B is turned on, the positive temperature coefficient thermistors PTC1 and PTC2 that control the energization to the heater 18 do not work at all, and the heater 18 is continuously energized.
Kerosene is not supplied into the vaporization chamber 2 because the output of the comparator IC _1-2 remains "low". Therefore,
The temperature of the vaporizer main body 1 reaches 500° C., and the tar attached to the vaporization chamber 2 and the vaporization stabilizer 17 is thermally decomposed and removed.

[Other Examples]

In the above embodiment, the ignition timing is controlled by the positive temperature coefficient thermistor PTC2, but as shown in FIG. 5, the ignition may be performed after a certain period of time from the start of energization. FIG. 5 corresponds to the circuit section 30 surrounded by the dashed line in FIG. 3. In FIG. The difference from Fig. 4 is that instead of the thermistor PTC2, a capacitor Ca is connected in series with the resistor _R16 , and a resistor Ra is also connected.
The reason is that a time constant circuit is formed by this series connection. In this way, the comparator IC _1-2 will be turned off from the time when the current is applied until the capacitor Ca is charged to a predetermined voltage, and then turned on to perform the ignition operation. This charging time is, for example, 1
You can set it to about a minute.

As described above, according to the present invention, it is easy to ignite, ignition can be performed reliably and quickly, and the preheating time can be shortened, which is a remarkable effect.

[Brief explanation of the drawing]

Figure 1: Schematic configuration diagram of the vaporizing oil combustor of the present invention, Figure 2: Electrical circuit diagram of the same vaporizing oil combustor, Figure 3: Circuit diagram of the vaporizing oil combustor, Figure 4
Figure: Main part circuit diagram of the combustor of the present invention, Figure 5: Main part circuit diagram of another embodiment. Code, 1: Vaporizer body, 2: Vaporization chamber, 4: Gas injection nozzle, 17: Vaporization stabilizer, 18: Heater, 24: Burner, SW _A , SW _B : Dry firing indicator switch, PTC1, PTC2: Thermistor,
IC _1-1 , IC _1-2 : Comparator.

Claims (1)

[Scope of Claims] 1. A vaporizing oil combustor in which liquid fuel is supplied into a vaporizing chamber, and vaporized gas vaporized therein is guided to a gas injection nozzle and combusted by a burner,
In a device equipped with a heating control means for controlling the temperature of the vaporization chamber to a constant temperature during combustion, the ignition control means performs an ignition operation at a predetermined temperature before the preheating temperature of the vaporization chamber before ignition reaches the constant temperature. A vaporizing oil combustor equipped with