JP2967654B2 - Liquid fuel 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 combustion apparatus for premixing and burning a vaporized liquid fuel with combustion air.

[0002]

2. Description of the Related Art FIG. 12 shows, for example, Japanese Patent Application No. 3-314216.
FIG. 1 is a cross-sectional view of a conventional liquid fuel combustion device shown in the specification. In the figure, a vaporization chamber 1 is a chamber for vaporizing liquid fuel, and an electric heater 2 for heating the vaporization chamber 1 is embedded in a side wall of the vaporization chamber 1. And
A throttle unit 3 is fitted and fixed to the upper part of the vaporization chamber 1.
A burner head 4 is provided on the throttle unit 3, and a plurality of flame holes 5 are provided on a side wall of the burner head 4. Further, in the burner head 4, a wire mesh 6 is wound around the outer peripheral surface of the burner head 4 in close contact, and a cap 7 is provided on an upper portion thereof. In order to fix the burner head 4 and the cap 7 to the throttle unit 3, one end of a special screw 8 is embedded in the throttle unit 3.

Here, a mixing plate 9 having a plurality of holes on the bottom surface is provided in the burner head 4, and the vaporized liquid fuel is rectified in the mixing plate 9 before the plurality of flame holes. It will squirt from 5. In addition, an annular flame holding ring 10 is attached to the upper part of the vaporization chamber 1 so as to surround the burner head 4.

By the way, on the side wall of the vaporization chamber 1, the vaporization chamber 1
A nozzle 11 opening inside is installed, and this nozzle 11 is connected to an air supply pipe (not shown) communicating with a blower (not shown). Also, the nozzle 11
It comprises an inlet 11a, a taper 11b and a throat 11c. On the other hand, the liquid fuel in a fuel tank (not shown) is supplied to the vaporization chamber 1 by a fuel pump (not shown) via a fuel supply pipe 12, and the fuel at the tip of the fuel supply pipe 12 is provided. The supply port 12a is connected to the nozzle 11
And coaxially protruding from the throat 11c.

Next, the operation will be described. By energizing the electric heater 2, the vaporization chamber 1 is preheated to a temperature (200 to 300 ° C.) necessary for vaporizing the liquid fuel. After the preheating is completed, the combustion air sent from the blower to the air supply pipe is
The gas is supplied from the nozzle 11 to the vaporization chamber 1. From the fuel supply pipe 12, liquid fuel is supplied to the vaporization chamber 1 in such an amount that the primary air ratio (= supply air amount / theoretical air amount) becomes about 0.8.

[0006] The supplied liquid fuel is atomized by the shear force of the combustion air, and is vaporized on a preheated vaporized surface. When the vaporized liquid fuel passes through the throttle section 3, it is further premixed with the combustion air, so that the concentration distribution becomes uniform. After this,
The premixed gas of the vaporized fuel and the combustion air is rectified by passing through a plurality of holes in the bottom surface of the mixing plate 9, and the vertical flow velocity distribution of the burner head 4 becomes uniform by the effect of the side wall of the mixing plate 9. . The premixed gas is ignited by an igniter (not shown) on the flame hole 5 of the burner head 4 to form a primary flame 14 and a secondary flame 15. After the start of combustion, heat is recovered from the flame by the flame holding ring 10 or the like, so that the vaporization chamber 1 is heated, so that input to the electric heater 2 is unnecessary.

[0007]

At the time of extinguishing a conventional premixed combustion apparatus as described above, the application of voltage to the fuel pump and the blower was simultaneously canceled. In this case, while the fuel pump stops almost instantaneously, the blower stops rotating after a few seconds, even if the application of the voltage is stopped, due to its inertia. Therefore, the fuel decreases very quickly as shown by the solid line in FIG. 13. When the power supply to the fuel pump is stopped at T ₀ , the evaporation amount becomes zero at T ₁ although it is slightly delayed due to vaporization or the like. On the other hand, reduction of the combustion air is slow when compared to the fuel supply at T ₂ as shown by the broken line is stopped. In this type of combustor, T ₀
Until the time, combustion is continued because the ratio of combustion air to fuel (primary air ratio) is in the combustible range, but after T, the air becomes excessive and the flame blows off.
Thus, due to the imbalance between the decreasing speeds of the two, the combustion air / fuel ratio (primary air ratio) at the time of fire extinguishing increases instantaneously, and the flame blows out. It becomes an unpleasant odor accompanied by and is discharged indoors.

In order to solve such a problem, conventionally, as disclosed in Japanese Utility Model Publication No. 3-45010, the combustion air / fuel ratio (primary air ratio) at the time of fire extinguishing is kept constant to reduce the amount of normal combustion. A method of minimizing the state to below the level has been considered. FIG. 14 shows a vaporizer-type combustor according to the embodiment of the Utility Model Publication. In FIG. 14, fuel vaporized by the carburetor heater 2 is jetted from the nozzle 31 to the burner 32, exits from the burner port, and burns. In this case, the combustion air is sucked from the surroundings by the ejector effect when the vaporized fuel is ejected from the nozzle 31. To change the amount of combustion in such a configuration, the amount of fuel supplied by the pump 21 is changed. On the other hand, since the combustion air is sucked by the ejector effect, the combustion air increases and decreases in proportion to the amount of fuel ejected from the nozzle 31. Therefore, if the amount of combustion is reduced during fire extinguishing,
The flame becomes smaller while the primary air ratio remains almost constant, and approaches the burner 32 surface. When the flame approaches the burner 32, the amount of heat transfer from the flame to the burner 32 increases, and the flame is cooled and extinguished. Then, the solenoid valve 33 is closed at or near the time when the flame has disappeared. Since the fuel and the combustion air cannot be independently varied in the combustor having such a configuration, the supply of both the fuel and the combustion air is stopped when the solenoid valve 33 is closed. It remains unburned without being exhausted. Therefore, in this case, although the unburned fuel slightly decreases as compared with that in FIG. 13, the unburned mixture gradually diffuses to the outside from the burner 32, so that the unpleasant odor continues for a long time. I do.

Further, as another method for improving the odor at the time of fire extinguishing, Japanese Utility Model Publication No. Sho 61-30035 and Japanese Utility Model Publication No.
No. 9809, part of the combustion air is released at the time of fire extinguishing, and the flame blows out at the time of fire extinguishing (blow o).
ff) is being considered. Specifically, in the case of the above-mentioned Japanese Utility Model Publication No. Sho 62-29809, a valve is provided in the middle of the air passage for combustion air, and a part of the combustion air is released to the outside when the fire is extinguished. FIG. 15 shows the state of fuel and combustion air at the time of fire extinguishing in this case. Fire extinguishing early T
_{At time 0, the} combustion air is reduced as shown by the broken line, so that the time T at which the primary air ratio at which blowout occurs is delayed, and FIG.
Blow-off does not occur even with a small amount of combustion as compared with the three. Therefore, unburned fuel slightly decreases. However, since in these cases the method of stopping the blower and the fuel pump is the same as the conventional, time until the combustion air and fuel becomes zero (between T ₀ through T ₁ and between T ₀ through T ₂ in FIG. 15)
However, the reduction ratio of the unburned fuel in the hatched portion is small. To reduce unburned fuel in the shaded area, it is sufficient to increase the proportion of combustion air that escapes to the outside, but in this case yellow fuel and soot are generated because the fuel becomes excessive when the combustion air decreases. . Further, in these embodiments, a mechanism for releasing combustion air is required, so that the structure around the combustor is complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and does not complicate the structure of the combustor, reduces the odor immediately after the fire is extinguished, and prevents the odor from continuing for a long time. It is intended to obtain a fuel combustion device.

[0011]

According to the liquid fuel combustion apparatus of the present invention , at the time of the fire extinguishing operation , at least the flame extinguishing point of the flame is reduced.
Until then, the rate of decrease of combustion air is equal to the rate of decrease of liquid fuel.
It is configured to supply air for a predetermined time after the fire is extinguished, as well as to increase the speed so that it does not become larger .

Specifically, the rate of reduction of the combustion air is increased by braking the blower.

Then, after the supply of the combustion air becomes zero, the blower is operated again to supply the air for a predetermined time.

Further, in the fire extinguishing operation, the combustion air supply amount starts decreasing before the liquid fuel supply amount starts decreasing.

Further, during the fire extinguishing operation, the supply amounts of the liquid fuel and the combustion air are reduced at substantially the same rate, and the supply amount of the liquid fuel is started to decrease before the supply amount of the combustion air starts decreasing. .

Further, during the fire extinguishing operation, the supply amounts of the combustion air and the liquid fuel are reduced at substantially the same rate, and only the supply of the liquid fuel is stopped near the flame extinction point .

[0017]

Further, after only the supply of the liquid fuel is stopped, the supply amount of the combustion air is kept constant for a predetermined time.

[0019]

According to the present invention, at least a fire extinguishing operation is performed.
Up to near the flame extinction point, the decreasing speed of the combustion air approaches the decreasing speed of the fuel, so that the mixture concentration is in the flammable range up to a small amount of combustion, making it difficult for the flame to blow out.
Less unburned fuel. Further, since the combustion air is supplied even after the flame has run out, a small amount of unburned fuel in the burner is exhausted, and the odor does not continue for a long time.

Further , after the supply of the combustion air becomes zero, the blower is operated again to supply the air for a predetermined time,
If only the supply of the liquid fuel is stopped and then the supply amount of the combustion air is kept constant for a predetermined time, the unburned fuel remaining in the vaporization chamber is reliably exhausted in a shorter time.

[0021]

【Example】

Embodiment 1 FIG. Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a liquid fuel combustion apparatus according to one embodiment of the present invention. Note that the same or corresponding parts as those in the conventional example shown in FIG. 12 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, a fuel pump 21 is used for the fuel supply device as in the conventional example. One end of the fuel pump 21 is located in the fuel tank 22 and the other end is connected to the fuel supply pipe 12.
It is connected to the. The combustion air is supplied by a blower 24 via an air supply pipe 23. Fuel pump 21 and blower 24
Is provided with a control circuit 25 for controlling the power supply.

Next, the operation will be described. The operation of starting combustion (ignition) is almost the same as in the conventional example. When the vaporization chamber 1 is heated to a predetermined temperature (200 to 300 ° C.), the blower 24 rotates and the amount of air required for combustion is supplied to the vaporization chamber 1. After operating the ignition device (not shown), the supply of liquid fuel is started by the fuel pump 21. The liquid fuel jetted into the vaporization chamber 1 is vaporized on the vaporization surface and mixed with the combustion air to become a premixed gas. The premixed gas passes through the throttle portion 3 and the mixing plate 9 and is ignited on the flame holes 5 of the burner head 4 to form a primary flame 14 and a secondary flame 15.

When the user turns off the power switch (not shown) to extinguish the fire, the control circuit 2
At 5, the application of the voltage to the fuel pump 21 is stopped. The method of stopping a fuel pump in this case is the same as conventional, a decrease in the fuel is the same reduction rate as in FIG. 13 of the conventional example becomes zero at time T ₀ through T ₁ as shown by the solid line in FIG. On the other hand, regarding the combustion air, the drive circuit of the blower 24 is controlled by the control circuit 25.
The air blower 24 is braked by means such as half-wave rectification or full-wave rectification of the AC power supply to reduce the air flow rate. As shown by the broken line in FIG. 2, the flow rate of the combustion air at this time becomes zero in a short time as compared with the conventional example in FIG. Accordingly, as the combustion air approaches the fuel decreasing speed, the time (between T _{0 and} T) during which the ratio of the combustion air and the fuel (primary air ratio) is in the flammable range becomes longer, and the flame blows out to a small amount of combustion. It becomes difficult. Therefore, the amount of unburned fuel shown by the oblique lines in FIG. 2 is reduced. Furthermore, at the time when the flame blows out (at time T), the combustion air is not zero,
The unburned fuel slightly remaining in the burner is exhausted by the combustion air, and the odor does not continue for a long time.

According to the measurement by the inventors, in this embodiment, the fuel reduction time T _{0 to} T ₁ is about 0.2 seconds, whereas the fuel supply of the conventional embodiment is not performed without braking the blower 24. In the case where the application of the voltage is simply canceled, the reduction time T _{0 to} T ₂ of the combustion air is about 15 seconds, and the combustion air is about 1/75 of the reduction rate of the fuel. On the other hand, when the blower 24 is braked by half-wave rectification, the combustion air reduction time T
₀ through T ₂ is about 0.4 seconds, decreasing time of combustion air approaches to about 1/2 of the reduced time of the liquid fuel. Further, since the brake is applied to the blower 24 against the inertial force of the rotation of the blower 24, the combustion air cannot be reduced instantaneously as much as the fuel, so that both reduction speeds do not become the same. Therefore, the reduction rate of the fuel and the combustion air as shown in FIG. 2 can be realized relatively easily.

FIG. 3 shows a typical odor measurement result in this case.
It is. FIG. 3 shows the hydrocarbon (Hydrocarbon = HC) concentration, which is an index indicating the magnitude of the odor. In the conventional fire extinguishing method, since there is a large amount of unburned fuel as shown in FIG. 13, HC has a high concentration immediately after the fire is extinguished as shown by a broken line in FIG. On the other hand, in the fire extinguishing method according to the present embodiment, the amount of unburned fuel is very small as shown in FIG. I do.

Embodiment 2 FIG. Here, the unburned fuel increases as the decreasing speed of the combustion air becomes slower, which is closer to a case where braking is not applied to the blower 24, and the odor reducing effect becomes smaller. When the reduction rate of the combustion air is 1/10 of the reduction rate of the liquid fuel, the unburned fuel is reduced by only about 10%. In order to increase the odor reduction effect when the combustion air decreasing speed is low, the time T ₀ ′ at which the combustion air starts decreasing as shown in FIG. 4 may be increased. In this case, the time T at which the flame blows out is later than when the fuel and combustion air are simultaneously reduced, and the unburned fuel is reduced. However, it takes care for leading the gas mixture between 'excessively early T _0' extremely time T ₀ through T ₀ becomes too dark to the occurrence of yellow flame and soot, shown in the conventional example of FIG. 15 As described above, a mechanism for releasing a part of the combustion air to the outside at the time of fire extinguishing is unnecessary, and there is an advantage that the structure of the combustor does not need to be complicated.

Embodiment 3 FIG. On the other hand, the effect of reducing unburned fuel is greater as the rate of decrease in combustion air is closer to the rate of decrease in liquid fuel. Decrease. Then, the flame approaches the wire mesh 6 on the outer peripheral surface of the burner head 4,
The flame cools and extinguishes. Therefore, similarly to the above-mentioned Japanese Utility Model Publication No. 3-45010, although the amount of unburned fuel is reduced, the unburned fuel is gradually diffused after extinguishing and the unpleasant odor continues. In this case the combustion air reduces the time T ₀ through T ₂ and the fuel decrease time T ₀ through T ₁ are approximately the same, in order to increase the effect of reducing unburned fuel, combustion air, as shown in FIG. 5 What is necessary is just to slightly delay the time T ₀ ′ at which the reduction starts. In this case, the time T ₁ when the fuel becomes zero
Since the air is supplied thereafter, unburned fuel does not remain in the vaporization chamber 1. However, extremely at time T ₀ '
It should be noted that delaying the time will cause the flame to blow out before the combustion air decreases.

In each of the above embodiments, the fuel pump 21 is used as the fuel supply device. However, similar effects can be obtained by using a constant oil leveler and a pressure pipe as described in the fifth embodiment. .

Embodiment 4 FIG. Next, another embodiment will be described. In this embodiment, the configuration of the equipment and the fire extinguishing operation are the same as in the first embodiment. The difference is that the blower 24 is restarted after the fire is extinguished, and the air is again supplied to the vaporizer 1 as shown in FIG. In this case, if the vaporization chamber 1 is in the same state as in the early stage of use, the effect is the same as in the first embodiment even if air is supplied again after the fire is extinguished. However, if the vaporization chamber 1 becomes dirty with use time and tar and other contaminants adhere thereto, vaporization of the liquid fuel is delayed, and a small amount of fuel remains in the vaporization chamber 1 even after the combustion air becomes zero. Become like In this case, since the remaining fuel gradually diffuses from the vaporization chamber 1, the odor continues for a long time, and the discomfort is increased. Therefore, in order to avoid such a situation, if the air is supplied again after the fire is extinguished,
Fuel remaining inside the vaporizer 1 is discharged in a short time,
The unpleasant odor will not last for a long time.

Embodiment 5 FIG. Next, another embodiment of the present invention will be described. FIG. 7 shows a liquid fuel combustion apparatus according to Embodiment 5 of the present invention. The same or corresponding parts as those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted.

In this embodiment, a constant oil leveler 26 is provided in the fuel supply device.
And a pressure tube 27 are used. A fuel pump 28 for maintaining the oil level at a constant level is installed in the constant oil level unit 26 and supplies kerosene from the fuel tank 22 to the constant oil level unit 26. The fuel supply pipe 1
Two proximal ends are located. Pressurizing pipe 27 is air supply pipe 2
The static pressure of No. 3 is transmitted to the constant oil level unit 26, and the static pressure is turned on / off by opening / closing a pressurized solenoid 29 provided on the way. A blower 24 is connected to an end of the air supply pipe 23, and a control circuit 25 is installed to control opening / closing of the blower 24 and the pressure solenoid 29.

Next, the operation will be described. The operation from ignition to normal combustion in this embodiment is almost the same as in the conventional example.
When the vaporization chamber 1 is heated to a predetermined temperature (200 to 300 ° C.), the blower 24 rotates and the amount of air required for combustion is supplied to the vaporization chamber 1. After the ignition device (not shown) is activated, the pressurizing solenoid 29 is opened, and the static blast pressure is applied to the constant oil level unit 26. The fuel flow rate corresponding to the static blast pressure and the differential pressure of the vaporization chamber 1 is increased. Is supplied to the vaporization chamber 1. The liquid fuel jetted into the vaporization chamber 1 is vaporized on the vaporization surface and mixed with the combustion air to become a premixed gas. The premixed gas passes through the throttle portion 3 and the mixing plate 9 and is ignited on the flame holes 5 of the burner head 4 to form a primary flame 14 and a secondary flame 15.

The fire extinguishing operation is as follows. When the user turns off a power switch (not shown), the blower 24
Is switched in the control circuit 25, and the blower 24 is braked to reduce the air flow rate by means such as half-wave rectification or full-wave rectification of the AC power supply. In this case the flow rate of the combustion air becomes zero in a short time from the time T ₀ as shown by the broken line in FIG. 8 until T _2. On the other hand, as for the fuel, since the pressurized solenoid 29 is opened and the static air pressure is applied to the oil level indicator 26, when the combustion air is changed, the pressure on the oil level indicator 26 also changes accordingly. The supplied liquid fuel also decreases at the same rate as the fuel air. The fuel flow rate at this time decreases from the time T _{0 to the} time T ₁ ′ at the same rate as the combustion air as shown by the solid line in FIG. Therefore, the amount of combustion decreases while the combustion air / fuel ratio (primary air ratio) is kept constant, and the flame approaches the wire mesh 6 on the outer peripheral surface of the burner head 4. T ₁ ′ immediately before the flame is cooled by the wire mesh 6 and extinguished.
At that time, the pressurizing solenoid 29 is closed to stop the action of the static air blowing to the constant oil level unit 26, thereby stopping the fuel supply. Then, since the fuel sharply decreases from the time T ₁ ′ to the time T ₁ , the primary air ratio sharply increases, and the flame blows out at the time T immediately before the quenching action of the wire mesh 6 works. When such a fire extinguishing operation is performed, the fuel can be burned up to just before the flame is extinguished by the wire mesh 6, so that the amount of unburned fuel is reduced as compared with FIG. Very small amount. Furthermore, when the flame blows out (at time T)
Since the combustion air is not zero, the unburned fuel slightly remaining in the burner is exhausted by the combustion air, and the odor does not continue for a long time. Incidentally, T ₁ 'timing of example T _1' to previously obtain beforehand such that unburned while changing the discharge time is also minimal incombustible fuel with minimal, in the control circuit 25 as the time interval from example T ₀ It is stored in memory.

FIG. 9 shows a result of a representative odor measurement performed by the inventors in this embodiment. In FIG. 9, as in FIG. 3, hydrocarbon (Hydrocarbon = HC) is an index indicating the magnitude of the odor.
Shows the concentration. In the fire extinguishing method according to the present embodiment, FIG.
As shown in the figure, the amount of unburned fuel is very small, and the amount thereof is even smaller than that in the first embodiment.
Can be reduced to about 1/5 of the conventional case.

Embodiment 6 FIG. In the fifth embodiment, the case where the brake is applied to the blower 24 at the time of extinguishing the fire has been described. However, even if the blower 24 is stopped for several seconds as in the conventional example, the effect of reducing the odor is the same. In the fire extinguishing operation in this case, first, the application of the voltage to the blower 24 is stopped. As in the conventional example, the blower 24 gradually decreases its rotation speed for inertia and stops after a few seconds. At this time, the flow rate of the combustion air decreases as shown by the broken line in FIG. On the other hand, since the supplied fuel has the pressurized solenoid 29 open, the amount of combustion decreases with the primary air ratio kept constant as in FIG. When the pressurized solenoid 29 is closed at T ₁ 'immediately before the flame extinguishes and the fuel supply is stopped, the flame blows out at T. The difference from FIG. 8 is the time from T _{0 to} T ₂ , and the time from the start to the end of the fire extinguishing operation is longer than that in FIG. Although the fire extinguishing operation of FIG. 8 is completed within one second after the power switch is turned off, several seconds to several tens of seconds are required in this embodiment. However, the amount of unburned fuel is the same as in FIG. 8, and the odor reduction effect is the same as in FIG.

Embodiment 7 FIG. Further, in the above embodiment, the constant oil level unit 26 and the pressurizing pipe 27 are used as the fuel supply device, but the same effect can be obtained by using the fuel pump 21 described in the first embodiment instead. In this case, in order to decrease the fuel as shown in FIG. 8 or FIG. 10, the power supply frequency of the fuel pump 21 may be changed over time by the control circuit 25 so as to synchronize with the reduction rate of the combustion air.
Then, at T ₁ ′ immediately before the flame is cooled and extinguished by the wire mesh 6, the voltage applied to the fuel pump 21 is turned off to stop the fuel supply. Then, also in this case, since the fuel sharply decreases from T ₁ ′ to T ₁ , the primary air ratio sharply increases, and the flame blows out at T immediately before the quenching action of the wire mesh 6 works.
The timing of T ₁ ′ may be stored in the memory of the control circuit 25 in advance. When such an operation is performed, the reduction of fuel and fuel air during fire extinguishing is the same as in FIG. 8 or FIG. 10, and the odor reduction effect is the same as in FIG.

Embodiment 8 FIG. Next, another embodiment of the present invention will be described. Also in this case, the configuration of the device is the same as that of the fifth embodiment, but the control circuit 25 is partially different, and the way of reducing the combustion air at the time of fire extinguishing is as shown in FIG. In other words, the T immediately before the flame is extinguished by the wire mesh 6 on the surface of the burner head 4.
_{At 1} ', the fuel is rapidly reduced by closing the pressurizing solenoid 29, and at the same time, the rotation speed of the blower 24 is maintained to keep the combustion air flow rate constant. After that, the power supply to the blower 24 is stopped at T ₀ ′ after a certain time has elapsed. When the combustion air is changed in this way, the process until the flame disappears is the same as that of the fifth embodiment, and the amount of unburned fuel becomes very small. The difference from the fifth embodiment is that since the combustion air flow rate after the time T when the flame has disappeared is large, the effect of exhausting the unburned fuel to the outside is strong. That is, since the combustion air after the extinguishing does not become zero, the fuel remaining slightly in the carburetor 1 is instantaneously discharged to the outside and does not remain in the vaporization chamber 1. Also, in this case, similarly to the fourth embodiment,
Even when tar or the like adheres to the vaporizer 1 and vaporization is delayed, the residual fuel is exhausted to the outside by the combustion air, so that the odor does not continue for a long time, and is very effective.

[0039]

As described above, according to the present invention , at the time of the fire extinguishing operation , at least the vicinity of the flame extinguishing point of the flame becomes the combustion air.
Qi reduction rate not greater than liquid fuel reduction rate
With Quicken extent, since it is configured to also supply a predetermined time air after a fire, without complicating the structure of the combustor, the odor immediately after extinguishing less, no liquid fuel combustion odor continues a long time A device is obtained.

Specifically, the rate of reduction of the combustion air is increased by braking the blower . Furthermore, if the combustion air supply is started to decrease before the liquid fuel supply starts decreasing during the fire extinguishing operation , the combustion air reduction rate is increased.
Even when the size cannot be increased, the odor reduction effect can be increased.
You. In addition, during the fire extinguishing operation , the supply amounts of the liquid fuel and the combustion air are reduced at substantially the same rate, and the liquid fuel supply amount is started to decrease before the combustion air supply amount starts decreasing, or the combustion is performed during the fire extinguishing operation. If the supply amount of air and liquid fuel is reduced at almost the same rate and only the supply of liquid fuel is stopped near the flame extinction point , the fuel
Reduce the supply of burned air and liquid fuel at approximately the same rate
Therefore, the amount of combustion decreases while the primary air ratio remains constant,
The energy reduction effect can be increased .

After the supply of combustion air becomes zero, the blower is operated again to supply air for a predetermined time, or after only the supply of liquid fuel is stopped, the supply amount of combustion air is kept constant for a predetermined time. If it is kept, the unburned fuel remaining in the vaporization chamber is surely exhausted in a shorter time.

[0042]

[Brief description of the drawings]

FIG. 1 is a sectional configuration diagram showing a liquid fuel combustion device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing how fuel and combustion air are reduced according to the first embodiment of the present invention.

FIG. 3 is an explanatory view showing odor discharge of the conventional device and the first embodiment.

FIG. 4 is an explanatory diagram showing how fuel and combustion air are reduced in Embodiment 2 of the present invention.

FIG. 5 is an explanatory diagram showing how fuel and combustion air are reduced in Embodiment 3 of the present invention.

FIG. 6 is an explanatory diagram showing how fuel and combustion air are reduced in Embodiment 4 of the present invention.

FIG. 7 is a sectional view showing a configuration of a liquid fuel combustion apparatus according to Embodiment 5 of the present invention.

FIG. 8 is an explanatory diagram showing how fuel and combustion air are reduced in a fifth embodiment of the present invention.

FIG. 9 is an explanatory view showing odor emission of the conventional device and the fifth embodiment.

FIG. 10 is an explanatory diagram showing how fuel and combustion air are reduced in a sixth embodiment of the present invention.

FIG. 11 is an explanatory diagram showing how fuel and combustion air are reduced in a seventh embodiment of the present invention.

FIG. 12 is a sectional view showing a configuration of a combustor of a conventional liquid fuel combustion device.

FIG. 13 is an explanatory diagram showing how fuel and combustion air are reduced in a conventional liquid fuel combustion device.

FIG. 14 is a sectional view showing a configuration of a conventional combustor disclosed in Japanese Utility Model Publication No. 3-45010.

FIG. 15 is an explanatory diagram showing a state of reduction of fuel and combustion air in a conventional combustor disclosed in Japanese Utility Model Publication No. Sho 62-29809.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vaporization room 5 Flame hole 12 Fuel supply pipe 23 Air supply pipe 24 Blower 25 Control circuit 26 Constant oil leveler 27 Pressurization pipe

──────────────────────────────────────────────────の Continuation of the front page (56) References JP-A-64-23016 (JP, A) JP-A-1-281324 (JP, A) JP-A-62-160150 (JP, U) 44652 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) F23N 1/02 F23N 3/08 F23N 5/20

Claims (7)

(57) [Claims] 1. A fuel supply means for supplying liquid fuel, a blower for supplying combustion air, a control circuit for controlling the blower and the fuel supply means, and combusting a premix of the liquid fuel and combustion air. In a combustion device having a flame hole , at the time of a fire extinguishing operation , at least up to near a flame extinguishing point of the flame.
Is greater than the rate of decrease of liquid fuel
Kunara with Quicken extent no liquid fuel combustion apparatus characterized by being configured to supply after extinguishing the flame also predetermined time air. 2. The method of claim 1, wherein the rate of decrease of the combustion air brakes the blower .
2. The liquid fuel combustion device according to claim 1, wherein the speed is increased by performing the operation . 3. The liquid fuel combustion apparatus according to claim 2, wherein after the supply of the combustion air becomes zero, the blower is operated again to supply the air for a predetermined time. 4. The liquid fuel combustion apparatus according to claim 1, wherein the combustion air supply amount starts decreasing before the liquid fuel supply amount starts decreasing during the fire extinguishing operation. 5. The method according to claim 1, wherein the supply amounts of the liquid fuel and the combustion air are reduced at substantially the same rate during the fire extinguishing operation, and the supply amount of the liquid fuel is started to decrease before the supply amount of the combustion air starts decreasing. The liquid fuel combustion device according to claim 1, wherein: 6. The method according to claim 1, wherein the supply amounts of the combustion air and the liquid fuel are reduced at substantially the same rate during the fire extinguishing operation, and only the supply of the liquid fuel is stopped near the flame extinction point . 2. The liquid fuel combustion device according to claim 1. 7. After stopping only the supply of the liquid fuel,
7. The liquid fuel combustion apparatus according to claim 6, wherein a supply amount of the combustion air is kept constant for a predetermined time .