JP2768270B2 - 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 used as a heat source for hot water supply / heating equipment and the like.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for petroleum combustion equipment to reduce noise, reduce the size of the equipment, expand the range of adjusting the amount of combustion, and further increase the capacity.

Conventionally, this type of liquid fuel combustion apparatus is roughly classified into a diffusion method in which liquid fuel is atomized by a spraying device and combustion particles are directly burned, and a vaporization method in which liquid fuel is once vaporized and burned. .

For example, in the latter type of vaporization type combustion apparatus, as shown in FIG. 11, liquid fuel supplied from a fuel tank 1 passes through an oil supply pipe 3 by a pump 2 and is buried in an electric heater 5 from a nozzle 4. The liquid is sent to the vaporizer 6 as droplets and is vaporized by heating. On the other hand, the combustion air passes through a ventilation path 8 by a ventilation fan 7, a part of which is introduced into a carburetor 6 from a primary air port 9, mixed with vaporized fuel to become a combustible mixture, and is uniformly mixed in a mixing chamber 10. After that, a flame is formed in the primary flame holes 12 constituting the burner head 11 and is burned in the combustion chamber 13. On the other hand, the remaining air is supplied from the secondary air passage 14 to the secondary air hole 15 provided near the primary flame hole 12 and contributes to combustion. Therefore, the combustion chamber 13
Since the high density blue flame 16 is formed, the size of the device can be reduced. Also, noise, which has been a problem of the former diffusion type combustion device, can be significantly improved.

[0005]

However, in the above-described conventional configuration, the adjustment of the combustion amount changes the rotation speed of the blower fan 8 and the output of the pump 2. However, for example, in the case of a water heater installed outdoors, Considering wind resistance and the like, it is difficult to significantly change the rotation speed of the blower fan 8 in practical use, and it is difficult to obtain a large adjustment range of the combustion amount. In addition, when the air amount is changed to change the combustion amount, the combustible mixer shows complicated behavior in the carburetor 6, and a part of the combustible mixer may flow backward in the air passage. In addition, there is a method in which the burner head is divided into a plurality of blocks and switched in order to increase the combustion amount adjustment width. However, there have been problems that the configuration and the control method are complicated and the cost is high.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to provide a liquid fuel combustion device which has a simple structure, has a large combustion amount adjustment width, has good wind resistance, and has no problems such as backflow. It is.

[0007]

According to the present invention, there is provided a fuel supply device for supplying a liquid fuel, a nozzle for ejecting the supplied liquid fuel, and a nozzle ejected from the nozzle. A vaporizer for heating and vaporizing the liquid fuel, a blower for supplying combustion air, an air passage connected to the air blower, and an open position and a closed position within the air passage.
And air amount adjusting means for changing the cross-sectional area of the airflow path by, downstream and the blowing of the air amount adjusting means
A primary air passage for guiding the combustion air to the carburetor from the road, and a secondary air passage having a portion that is formed outside the primary air passage in the air blowing path, continuously to a downstream side of the evaporator Mixing chamber, a primary flame formed downstream of the mixing chamber, and a secondary air set near the primary flame.
It has a secondary flame hole for supplying the combustion amount adjusting when the air amount adjustment
Change the air passage area by setting the joint means to the open or closed position.
And the open and closed positions of the air amount adjusting means.
In this configuration, the amount of air blown by each blower is changed .

According to a second aspect of the present invention, a primary air passage in the air passage for guiding the combustion air to the carburetor, and a cross-sectional area of the air passage at the entrance of the primary air passage being changed by opening and closing, The air flow control device has an air amount adjusting means for substantially closing the primary air passage when closed, and a primary air hole provided at a position facing the primary air passage of the air amount adjusting means.

Further, in the third aspect, a plurality of primary air holes are dispersedly provided with respect to the opening of the primary air passage.

A fourth aspect of the present invention is a primary air passage which is smaller in width than the air passage and substantially at the center of the air passage, and whose leading end extends to the inlet of the carburetor , and which has primary air ports on left and right wall surfaces. When the primary air supply unit so as to face the primary air passage tip vaporizer containing mouth is configured to have a vaporizer lid provided.

Further, in the present invention, an auxiliary air hole having an opening area smaller than that of the primary air port is provided at a position facing the primary air passage of the air amount adjusting means.

Further, in a sixth aspect, a guide plate is provided inside the left and right primary air ports at the end of the primary air passage.

[0013] Further, according to the present invention, the guide plate is provided with a slight gap from the left and right ends of the primary air passage.

Further, in the present invention, the guide plate is formed on the vaporizer lid. Further, the ninth aspect is configured such that a projection is provided upward on the bottom surface of the primary air passage outlet.

Further, a tenth aspect of the present invention is configured such that a closing portion protruding upward is provided on the bottom surface of the entrance of the primary air passage.

[0016] Further, in the eleventh aspect, the nozzle is provided near the primary air port in the primary air passage.

[0017]

According to the first aspect of the present invention, a primary air passage is provided.
And when an air amount adjusting means is provided in the air passage on the upstream side of the secondary air passage , and the air passage area is changed by this air amount adjusting means.
In both cases, the blower area is changed
Since the amount of air is changed, the amount of air for combustion can be largely controlled by opening and closing the air amount adjusting means, and the operation curve of the air blower can be changed , and good wind resistance can be maintained.

According to the second aspect of the present invention, the primary and secondary air amounts are simultaneously changed by opening and closing one air amount adjusting means, and the opening area to the primary air passage and the opening area to the secondary air passage are respectively reduced. Since it can be defined independently, there is an effect that the primary and secondary air distribution can be changed when the air amount adjusting means is opened and closed.

Further, according to the structure of the third aspect, when the air amount adjusting means is closed, the air flow rate distribution in the primary air passage is made uniform, and the generation of a large vortex is suppressed.

According to the fourth aspect of the present invention, high-speed primary air is supplied into the carburetor from the primary air ports provided on the left and right wall surfaces at the tip of the primary air passage, so that an air blocking layer is provided near the entrance of the carburetor. Is formed.

Further, according to the structure of the fifth aspect, the air amount adjusting means has an effect of reducing a negative pressure state in the primary air passage when the air amount adjusting means is closed.

Further, the function of suppressing eddy currents at the left and right ends of the primary air passage outlet is enhanced by the structure of the sixth aspect.

Further, according to the seventh aspect of the present invention, it is possible to supply air to the left and right ends in the carburetor, and to make the distribution of the combustible mixture uniform.

Further, the same operation as in the sixth and seventh aspects can be obtained by a simple configuration and processing without adding any special member or processing by the configuration of the eighth aspect.

Further, according to the ninth aspect of the present invention, there is an effect that an ascending air flow is formed in the vaporizer and vaporization is efficiently performed.

Further, according to the structure of the tenth aspect, the air amount adjusting means has an action of preventing the introduction of excess air into the primary air passage when the air amount adjusting means is closed.

Further, according to the structure of the eleventh aspect, air is always supplied to the vicinity of the nozzle, and the function of dispersing the fuel and cooling the nozzle is provided.

Specific effects of the above operation will be sequentially described in embodiments.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a liquid fuel combustion apparatus according to the present invention. Kerosene, which is a liquid fuel, is sucked up from a fuel tank (not shown) by a pump 17 which is a fuel supply means, and is supplied to a nozzle 19 by an oil feed pipe 18.
Supplied to Reference numeral 20 denotes a vaporizer set in front of the nozzle 19, in which a heater 21 is embedded. Reference numeral 22 denotes a blower for supplying combustion air, and an air passage 23 is connected to the blower.
Numeral 24 denotes an air amount adjusting means set in the air passage 23, and a damper 25 for changing the sectional area of the air passage 23 by opening and closing.
And a driving device 26 for driving the damper 25. The damper 25 may be a method of rotating or sliding two plates having openings parallel to the plate surface to change the opening area, or a method of rotating one plate around the plate surface as shown in FIG. In the latter case, opening and closing in the vertical direction (when opened, the position indicated by the dotted line in FIG. 1) or opening and closing in the horizontal direction may be used. The driving device 26 can use a stepping motor or a solenoid. Reference numeral 27 denotes a primary air passage provided on the downstream side of the air amount adjusting means 24, extending to the entrance of the carburetor 20, and separated from the secondary air passage 28. Reference numeral 29 denotes a vaporizer lid provided on the front surface of the vaporizer 20, and an opening is provided so that the tip of the primary air passage 27 faces. Reference numeral 30 denotes a mixing chamber, and 31 denotes a plurality of primary flame ports provided downstream of the mixing chamber, and has a large number of small holes formed on an upper surface thereof. Reference numeral 32 denotes a burner case that covers the entire combustion section, and a space inside the burner case is a secondary air passage 28. Reference numeral 33 denotes a secondary flame port having a large number of small holes formed on an upper surface thereof, and a plurality of secondary flame ports are alternately arranged with the primary flame port 31 so as to supply air near the primary flame port 31. Numeral 34 denotes a heat shield plate, inside which a combustion chamber 35 is formed. Reference numeral 36 denotes a heat receiving portion formed so as to protrude into the combustion chamber 35 on the back of the vaporizer 20. 37 is a heat exchanger.

In the above configuration, when a power supply (not shown) is turned on, the heater 21 is energized and the vaporizer 20 is heated. When the vaporizer 20 reaches a predetermined temperature, the blower 22 operates to supply air for combustion. After the air supplied to the air passage 23 is adjusted in the air amount by the air amount adjusting means 24,
The air is divided into primary air supplied into the primary air passage 27 and secondary air supplied into the secondary air passage 28. At the same time, the pump 17 operates and the fuel is sprayed from the nozzle 19 to the carburetor 20. The fuel is vaporized on the wall surface of the high-temperature vaporizer 20, is conveyed to the mixing chamber 30 while being mixed with the primary air, and is ejected from the primary flame port 31 as a combustible mixture.
At this time, the combustible air-fuel mixture is ignited by the discharge of an igniter (not shown) and combustion is started. Further, the secondary air passes through the secondary air passage 28 inside the burner case 32 and is supplied to the secondary flame port 33 arranged near the primary flame port 31, so that it burns blue flame in the combustion chamber 35. The high-temperature combustion gas generated by the combustion exchanges heat in the heat exchanger 37 and is discharged.

With this configuration, the range of adjusting the amount of combustion can be greatly expanded, and good wind resistance can be maintained in this wide range of adjustment. That is, as shown in FIG. 2A, at the point a where the amount of combustion is maximum, the damper 25 of the air amount adjusting means 24 is used.
And the rotation speed of the blower 22 is set to MAX (hereinafter, the damper 25).
Is opened ← → closed, the rotation speed of the blower 22 is set to MAX ← → M
(Represented by IN). When the output of the pump 17 is reduced to reduce the amount of combustion and at the same time the rotation speed of the blower 22 is reduced, the state becomes the open MIN at the point b. In the liquid fuel combustion apparatus without the air amount adjusting means 24, the combustion amount can not be deer Adjusts the range from point a to point b. However, in this embodiment, the combustion amount adjustment range can be increased. That is, when the combustion amount is to be further reduced, the damper 25 is closed and the rotational speed is increased (closed MAX), as shown by the point c. At the point c, the rotation speed of the blower 22 is high, but the combustion amount and the air amount are set to be substantially the same as at the point b. In order to further reduce the combustion amount, the number of revolutions is reduced to reach d (closed NIN). Conversely, when increasing the amount of combustion, d (closed MIN) → c '(closed MAX) →
b ′ (open MIN) → a (open MAX). At this time, a slight hysteresis is provided for the amount of combustion at the opening / closing position of the damper 25 in the decreasing direction and the increasing direction of the amount of combustion. Thereby, even if the hot water supply amount fluctuates near the opening / closing position of the damper 25, the state where the damper 25 opens and closes frequently can be avoided.

The air amount adjusting means 24 can continuously change the opening degree of the damper 25 as the combustion amount changes. However, delicate control is required and the control becomes considerably complicated. When applied, good characteristics can be obtained only by opening and closing operations.

FIG. 2 (b) shows a change in the amount of combustion and the CO2 characteristic which is one of the combustion characteristics. Basically, it shows the same behavior as the rotation speed of the blower 22, but C
The change in O ₂ is set to be small. Originally, if the combustion amount is the same, the air amount is constant even when the damper 25 is opened and closed, and therefore, the CO ₂ value is desirably constant. Such a condition depends on the size of the damper 25 (that is,
Of the primary air passage 27 and the size of the primary air passage 27 (that is, the distribution ratio between the primary air and the secondary air).

As described above, according to the embodiment shown in FIG. 1, the range of adjusting the amount of combustion can be greatly expanded. This is because, in practical use, the wind resistance can be maintained in the wide range of adjusting the amount of combustion. That is, looking at the PQ characteristics of the blower 22 as shown in FIG.
The characteristic curve changes from point a to point b on the load curve X between curve A and curve B from MAX to MIN. point b at the lower limit pressure P _b in order to maintain the wind performance, wind resistance performance can not be maintained when reducing the rotational speed of the blower 22 to less. Therefore, when the damper 25 is opened, the PQ characteristic curve becomes MAX.
→ The load curve Y changes from the point c to the point d on the load curve Y between the curve C and the curve D at MIN. Therefore, the lower limit pressure P
it is possible to change the air volume from Qa to Q _d to _d (P _b and the same).

On the other hand, when the air amount adjusting means 24 is not provided, the air amount is reduced by reducing the rotation speed of the blower 22 on the load curve X to reduce the air amount to Qb or less. Therefore, in addition to the pressure lower than the lower limit pressure Pb, if the number of revolutions is reduced too much, the variation in the number of revolutions cannot be compensated. Therefore, the air amount cannot be adjusted substantially below Qb.

When the air amount adjusting means 24 is located on the upstream side of the blower 22, the PQ characteristic of the blower 22 becomes the PQ characteristic when the damper 25 is opened as shown in FIG. The curve changes between the curve A 'and the curve B'. When the damper 25 is closed, the PQ characteristic curve changes from the curve C 'to the curve D', but the load curve is the same X 'as when the damper is opened. Will change above. Therefore, although the rotation speed of the blower 22 can be increased by closing the damper 25, the blower 22 is used at or below the lower limit pressure Pb, and cannot withstand actual use in terms of wind resistance. The air amount adjusting means 24 is placed in the air passage 23 (the blower 2
2) to improve wind resistance,
The combustion amount adjustment range can be expanded.

[0038] FIG. 4 in the embodiment according to aspect 2, the primary air
The distribution of air and secondary air is wider than in the embodiment shown in FIG.
It is to be prescribed. Numeral 24 denotes an air amount adjusting means, which comprises a damper 25 and a driving device 26, and changes the cross-sectional area of the air passage 23 by opening and closing. The damper 25 closes the primary air passage 27 when closed. Is set at the entrance. Further, when the damper 25 is closed, a primary air hole 38 is provided at a position facing the primary air passage 27.
Is provided. With this configuration, the distribution of the primary air and the secondary air can be strictly defined when the damper 25 is closed and when it is opened. That is, in the embodiment of FIG. 1, the primary air and the secondary air are distributed in the same air passage, and the primary air passage is also the secondary air passage.
It is defined by the open road.
But only by the opening and closing of the damper 25 is in contrast the embodiment of FIG. 4, Hirakiji the size of the primary air passage 27, closed in the distribution of primary air and the secondary air in the opening area of the primary air holes 38 Can be changed precisely and significantly . In other words, when the combustion amount is adjusted in a wide range, and when it is better to change the air distribution between when the damper 25 is opened and when the damper 25 is closed from the balance of the overall combustion characteristics, the opening area of the primary air hole 38 is optimized. By setting the value, an optimal air distribution can be realized.

FIG. 5 shows an embodiment according to claim 3, characterized in that the primary air holes 38 are provided in a distributed manner. For example, when the primary air hole 38 is provided at one central position as shown in FIG. 5F, the air supplied from the primary air hole 38 to the primary air passage 27 is rapidly diffused into a wide space, so that a vortex is formed. However, a complicated behavior is exhibited in the primary air passage 27, and a negative pressure region is formed. For this reason, the fuel vaporized by the vaporizer 20 may flow backward due to the vortex, condensate in the primary air passage 27, and wet the wall surface and the nozzle 19 in some cases. In view of this, in the embodiment of FIG. 5, the primary air holes 38 are provided in a dispersed manner, whereby the generation of a large vortex in the primary air passage 27 can be suppressed, and the backflow can be suppressed. The most common method of dispersing arrangement is to arrange small holes uniformly throughout as shown in FIG. 5 (a). However, the size of one hole is set to a size that does not cause a problem such as clogging of dust. It is necessary to keep.

As other arrangements, a slit arrangement as shown in FIGS. 5B and 5C or a dispersed arrangement in a horizontal row as shown in FIG. Further, as shown in FIG.
By increasing the primary air hole 39 at the position facing the nozzle 19 and increasing the amount of air near the nozzle 19, the nozzle 19
The effect of suppressing dew condensation on the surface can be increased.

FIG. 6 shows an embodiment corresponding to claim 4 to claim 11, which aims to further enhance the above-described backflow prevention effect and to solve various problems when used as an actual combustion device. I have. Explaining only the points different from the embodiment of FIG. 4, the primary air passage 27 is narrower than the air passage 23 and is set substantially at the center of the air passage 23, and the tip is located at the entrance of the vaporizer 20 and the front of the 20 faces the primary air supply unit 40 of the vaporizer lid 29 provided so as to close. Further, primary air ports 41 are provided on the left and right wall surfaces at the end of the primary air passage 27. With this configuration, most of the air sent from the blower 22 into the air passage 23 when the air amount adjusting means 24 is closed has the damper 25 closed, so that the damper 25 and the air passage 23 are closed as shown in FIG. The air is supplied to the secondary air passage 28 from the gap (dotted arrow), and a part of the air is supplied as primary air from the primary air port 41 into the carburetor 20 (solid arrow). At this time, since the air is intensively supplied from the left and right primary air ports 41, an air blocking layer is formed just near the entrance of the vaporizer 20, and the mixing effect in the vaporizer 20 due to the shielding effect. It is possible to prevent air from flowing back into the primary air passage 27. Originally, the primary air port 41 may have any shape as long as it can secure the amount of primary air necessary for combustion. However, in order to realize the shielding effect by the air flow, it is necessary to supply air intensively. Therefore, a slit shape as shown in FIG. 7 is desirable.

As shown in FIG. 6, an auxiliary air hole 42 having a smaller opening area than the primary air port 41 is provided at a position facing the primary air passage 27 of the damper 25. Example). If the auxiliary air hole 42 is not provided, no air is supplied into the primary air passage 27 when the damper 25 is closed, so that the pressure becomes negative. Although the backflow prevention effect is improved by the configuration of FIG. 6 due to the air blocking layer, the air-fuel mixture may cause backflow due to delicate pressure balance. Therefore, by supplying air from the auxiliary air hole 42, the negative pressure state in the primary air passage 27 can be reduced, and the backflow can be suppressed.

FIG. 8 shows a structure for further improving the backflow preventing effect in an embodiment corresponding to claim 6, wherein a guide plate 43 is provided inside the left and right primary air ports 41 at the end of the primary air passage 27. Is provided. Since the primary air passage 27 faces the primary air supply unit 40 provided in the carburetor lid 29 (not shown in FIG. 8), the primary air is supplied to the primary air ports 41 on the left and right ends of the primary air supply unit 40. At this time, a vortex is generated in the vicinity of the vaporizer lid 29, and the vortex may cause the mixed gas to flow back into the primary air passage 27. By providing the guide plate 43, this eddy current can be suppressed, and backflow into the primary air passage 27 can be prevented.

FIG. 9 shows an embodiment corresponding to claim 7, and FIG.
This is to solve the problem of the embodiment. That is, in the configuration of FIG. 8, the primary air is concentrated at the center of the carburetor, and the amount of air on both sides of the carburetor 20 decreases. Such non-uniform mixing in the vaporizer 20 is not completely eliminated by the time the air-fuel mixture reaches the primary flame port 31, and the state of flame formation may be non-uniform. In the embodiment of FIG. 9, the guide plate 43 ′ is provided with a slight gap 44 from the left and right ends of the primary air passage 27 to solve such a problem. With this configuration, the primary air port 4
A portion of the air supplied into the carburetor 20 from
To the two sides, and the unevenness of mixing in the vaporizer 20 is reduced, so that the state of formation of the flame at the primary flame port 31 is also improved.

FIG. 10 shows an embodiment according to claim 8, wherein the same effects as those of the embodiments shown in FIGS. 8 and 9 can be obtained with a simple and inexpensive configuration. FIG. 10A is an embodiment corresponding to FIG. 8, in which guide plates 45 are formed on both sides of the primary air supply unit 40 of the carburetor lid 29. FIG.
(B) is an embodiment corresponding to FIG. 9, in which a guide plate 45 ′ is formed in the primary air supply section 40 of the vaporizer lid 29 via a gap 44 ′. 8 and 9, extra processing steps such as welding and bending are required. However, since the guide plates 45 and 45 ′ can be formed integrally with the vaporizer lid 29 by the configuration of FIG. Processing is simple and inexpensive, and the same effects as in the embodiment of FIGS. 8 and 9 can be obtained.

Next, in the embodiment shown in FIG. 6, an upwardly projecting portion 46 is provided on the outlet bottom surface of the primary air passage 27.
This is an embodiment corresponding to the ninth aspect. With this configuration, the vaporization characteristics can be improved. That is, the liquid fuel ejected from the nozzle 19 collides with the wall surface of the vaporizer 20, but at the moment of collision, not all of the fuel is vaporized but scatters in the vaporizer 20 and recollides with the vaporizer 20.
It is vaporized by radiant heat in the inner space. Here, whether or not vaporization is efficiently performed greatly affects the size and power consumption of the vaporizer 20. When the vaporization is performed only in a part of the vaporizer 20, the vaporizer 20 becomes large and the power consumption becomes large in order to secure a vaporization area. The air supplied from the primary air passage 27 to the carburetor 20 is air necessary for combustion and also serves to transport fuel. Here, since the projecting portion 46 has a function of changing the flow of air upward, the fuel is also once transported upward, and is vaporized so as to spread over the entire space in the vaporizer 20. That is, since the entire vaporizer 20 can be efficiently used, the vaporizer 20 can be made compact and power consumption can be suppressed.

In the embodiment shown in FIG. 6, a closing portion 47 protruding upward is provided on the bottom surface of the inlet of the primary air passage 27. This is an embodiment corresponding to claim 10, and this configuration can improve the combustion state. Without the closing portion 47, when the air amount adjusting means 24 is closed, it is practically difficult to completely close the entrance of the primary air passage 27, and the primary air is supplied from the gap. Since the air amount becomes larger than the set air amount, the combustion characteristics may be affected. However, by having the closing portion 47, the primary air passage 27 can be almost completely closed when the air amount adjusting means 24 is closed, so that the primary air amount can be supplied as set and the combustion characteristics can be reduced. Variation can be reduced.

Further, in the embodiment shown in FIG.
9 is provided near the primary air port 41 in the primary air passage 27. This is an embodiment corresponding to claim 11. With this configuration, air can be intensively supplied to the vicinity of the nozzle 19, so that the liquid fuel can be scattered over a wide range of the vaporizer 20 and the nozzle 19 can be supplied. The fuel cell is cooled, and fuel accumulation is prevented, so that tar clogging of the nozzle 19 is suppressed, so that a very long life of the combustion device can be achieved.

[0049]

As described above, in the liquid fuel combustion apparatus according to the present invention, the fuel supply means for supplying the liquid fuel, the nozzle for ejecting the supplied liquid fuel, and the nozzle ejected from the nozzle are provided. A vaporizer for heating and vaporizing the liquid fuel;
A blower for supplying air for combustion, a blower passage connected to the blower, and an open position and a closed position within the blower passage .
And air amount adjusting means for changing the cross-sectional area of the airflow path by Rukoto, downstream of the air quantity adjusting means and the feed
A primary air passage for guiding the combustion air to the carburetor from the wind passage, and a secondary air passage having a portion that is formed outside the primary air passage in the blowing path, with the downstream side of the evaporator A mixing chamber, a primary flame port formed downstream of the mixing chamber, and a secondary space set near the primary flame port.
Have a secondary flame hole for air supply, combustion amount adjusting when the air amount
Change the air passage area by setting the adjustment means to the open or closed position
And the open and closed positions of the air amount adjusting means.
It is configured to change the amount of air blown by the blower at each location ,
When the area of the air passage changes, the amount of air blown from the blower changes.
Further, the combustion amount adjustment range can be widened. Also, an air amount adjusting means is provided in the air passage, and
By arranging the primary air passage and the secondary air passage ,
It can Rukoto to improve the wind performance.

According to a second aspect of the present invention, a primary air passage in the air passage for guiding combustion air to the carburetor, and a cross-sectional area of the air passage at the entrance of the primary air passage, which is changed by opening and closing, and closed. Sometimes the air amount adjusting means for substantially closing the primary air passage, and a primary air hole provided at a position facing the primary air passage of the air amount adjusting means, so that the air amount adjusting means is opened and closed to open the primary air passage. By simultaneously changing the amount of secondary air and independently defining the opening area to the primary air passage and the opening area to the secondary air passage, when the air amount adjusting means opens and closes, Since the distribution ratio of the secondary air can be set accurately, an optimum combustion state can be obtained in a wide range of adjusting the combustion amount.

Further, in the third aspect, since a plurality of primary air holes are dispersedly disposed with respect to the opening of the primary air passage, when the air amount adjusting means is closed, the flow velocity distribution of the air in the primary air passage is reduced. It can be made uniform and the generation of a large swirl in the primary air passage can be suppressed, so that the backflow of the air-fuel mixture into the primary air passage can be suppressed.

A fourth aspect of the present invention provides a primary air passage having a width smaller than that of the air passage and substantially at the center of the air passage, a tip extending to an inlet of the carburetor, and having primary air ports on left and right wall surfaces. since the vaporizer inlet to the primary air passage tip primary air supply unit to face it is configured to have a vaporizer lid provided, a blocking layer of the air by a high speed air supplied from the right and left primary air inlet Since it is formed, backflow into the primary air passage can be prevented.

Further, since the auxiliary air hole having an opening area smaller than that of the primary air port is provided at a position facing the primary air passage of the air amount adjusting means, a negative pressure in the primary air passage is provided. This has the effect of reducing the state and suppressing backflow.

Further, since the guide plate is provided inside the left and right primary air ports at the tip of the primary air passage, the generation of a vortex at the left and right ends of the primary air passage outlet is suppressed. Therefore, it is more effective for backflow.

Further, since the guide plate is provided with a slight gap from the left and right ends of the primary air passage, air can be supplied also to the left and right ends of the carburetor. The mixing state becomes good and the combustion state can be kept good.

Further, in the eighth aspect, since the guide plate is formed on the carburetor lid, the same effects as those of the sixth and seventh aspects can be obtained with a simple configuration and at a low cost. Can be.

Further, in the ninth aspect of the present invention, since the projecting portion is provided on the bottom surface of the outlet of the primary air passage, an upward air flow is generated in the vaporizer, and the air-fuel mixture is uniformly dispersed to make the entire vaporizer. Since the vaporizer can be used efficiently, the vaporizer can be made compact and power consumption can be reduced.

Further, since the closing portion protruding upward is provided on the bottom surface of the entrance of the primary air passage, the primary air passage is almost completely closed when the air amount adjusting means is closed, and the extra air is blocked. Since it is possible to prevent the inflow of air and supply the primary air amount as set, variations in combustion characteristics can be suppressed.

Further, since the nozzle is provided near the primary air port in the primary air passage, the dispersion of fuel is improved and the vaporization efficiency is improved, and the accumulation of fuel in the nozzle is prevented. Further, since the clogging of the tar is suppressed by cooling the nozzle, there is an effect that the life of the combustion device can be extended.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a liquid fuel combustion apparatus according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram of the liquid fuel combustion device of FIG. 1;

FIG. 3 is a characteristic diagram of a blower of the liquid fuel combustion device of FIG. 1;

FIG. 4 is a sectional view of a main part of a liquid fuel combustion apparatus according to another embodiment of the present invention.

FIG. 5 is a schematic view showing an embodiment of an air amount adjusting means.

FIG. 6 is a sectional view of a main part of a liquid fuel combustion apparatus according to still another embodiment of the present invention.

FIG. 7 is a perspective view of an essential part showing the effect of the liquid fuel combustion device of FIG. 6;

FIG. 8 is a perspective view of a main part of a liquid fuel combustion apparatus according to another embodiment of the present invention.

FIG. 9 is a perspective view of a main part of a liquid fuel combustion apparatus according to another embodiment of the present invention.

FIG. 10 is a perspective view of a main part of a liquid fuel combustion apparatus according to another embodiment of the present invention.

FIG. 11 is a sectional view of a main part of a conventional liquid fuel combustion device.

[Explanation of symbols]

 Reference Signs List 17 fuel supply means 19 nozzle 20 carburetor 22 blower 23 blower path 24 air amount adjusting means 27 primary air passage 28 secondary air passage 29 carburetor lid 30 mixing chamber 31 primary flame port 33 secondary flame port 38, 39 primary air hole 40 Primary air supply unit 41 Primary air port 42 Auxiliary air hole 43, 43 ', 45, 45' Guide plate 44, 44 'Gap 46 Projecting part 47 Closing part

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Seiichi Shinoda 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-2-78818 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F23D 11/24-11/34

Claims (11)

(57) [Claims] 1. A fuel supply means for supplying a liquid fuel, a nozzle for ejecting the supplied liquid fuel, a vaporizer for heating and vaporizing the liquid fuel ejected from the nozzle, and a blower for supplying combustion air. And an air passage connected to the blower, and an open position and a closed position within the air passage.
Therefore, the air amount adjusting means for changing the cross-sectional area of the air flow path, and whether the air flow amount adjustment means is downstream and in the air flow path.
A primary air passage for guiding the combustion air to et the vaporizer,
It is formed outside the primary air passage in the air blowing path
A secondary air passage having a portion, a mixing chamber provided continuously downstream of the vaporizer, a primary flame port formed downstream of the mixing chamber, and secondary air set near the primary flame port. For supply
It has a secondary flame hole of the combustion amount adjusting when the air amount adjusting means
When the air passage area is changed by setting the
In both cases, the air flow control means
A liquid fuel combustion device that changes the amount of air blown by each blower . Wherein air flow regulation means intended to exhibit the ability to substantially block the primary air passage closing with varying the cross-sectional area of more air passage to the opening and closing In the primary air passage inlet
There, the air quantity adjusting means liquid fuel combustion apparatus according to claim 1, wherein providing the primary air holes <br/> position location opposite the primary air passage to. 3. The liquid fuel combustion apparatus according to claim 2, wherein a plurality of primary air holes are dispersedly provided with respect to the opening of the primary air passage. 4. The primary air passage is smaller in width than the air passage and substantially at the center of the air passage, and the tip of the primary air passage extends to the entrance of the vaporizer and extends on the left and right wall surfaces. Primary air port
Has, to include a vaporizer lid primary air supply unit is provided so that the primary air passage tip to said vaporizer containing mouth faces
The liquid fuel combustion device according to claim 1 or 2, wherein: 5. The liquid fuel combustion apparatus according to claim 4, wherein an auxiliary air hole having a smaller opening area than the primary air port is provided at a position facing the primary air passage of the air amount adjusting means. 6. The liquid fuel combustion apparatus according to claim 4, wherein guide plates are provided inside the left and right primary air ports at the end of the primary air passage. 7. The liquid fuel combustion device according to claim 6, wherein the guide plate is provided with a slight gap from the left and right ends of the leading end of the primary air passage. 8. The liquid fuel combustion apparatus according to claim 6, wherein the guide plate is formed on a carburetor lid. 9. The liquid fuel combustion apparatus according to claim 4, wherein an upwardly projecting portion is provided on the bottom surface of the primary air passage outlet. 10. The liquid fuel combustion device according to claim 4, wherein a closing portion protruding upward is provided on the bottom surface of the inlet of the primary air passage. 11. The liquid fuel combustion device according to claim 4, wherein the nozzle is provided near the primary air port in the primary air passage.