JPH08296816A - Combustor - Google Patents

Abstract

PURPOSE: To maintain better combustion without change in the quantity of combustion for a long period time of by checking clogging as caused by the generation of tar of a vaporization element while preventing poor vaporization. CONSTITUTION: This apparatus is provided with a vaporization chamber 6 having a nozzle part 3 at one end thereof and a fuel supply port 8 at the other end thereof, a heater 10 to heat the vaporization chamber, a burner part 13 and a vaporization element 7 as a plurality of inorganic porous bodies with the opening rate thereof different provided in the vaporization chamber 6. The vaporization element as the inorganic porous bodies with the opening rate smaller on the side of a fuel supply port 8 and larger on the side of the nozzle part 3 is arranged in the vaporization chamber 6. Thus, an opening part of a tar generating part is increased to check clogging as caused by the generation of tar thereby preventing a lowering of the quantity of combustion and abnormal combustion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion apparatus for vaporizing a liquid fuel and ejecting the vaporized gas from a nozzle to burn the liquid fuel.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 6, in a combustion apparatus of this type, fuel is supplied from a cartridge tank 22 to a tank 21, and the fuel in the tank 21 is pumped by a pump 23 to a vaporization section 24 containing a vaporization element. Supplied. Then, the fuel is diffused by the vaporization element in the vaporization section 24 and further heated and vaporized to become fuel gas, which is ejected in the horizontal direction from the nozzle section 25. The fuel gas ejected from the nozzle portion 25 mixes the fuel gas and the primary air in the mixing pipe 26 provided on the downstream side of the vaporization portion 24 while sucking the primary air by the ejector effect, and is integrated with the mixing pipe 26. Is supplied to the burner unit 27 configured as above and burns. Combustion gas generated by the combustion is guided upward by a combustion cylinder 28 arranged so as to cover the periphery of the burner portion 27, and a duct 29 covering the combustion cylinder 28 blows the combustion gas.
It is mixed with the air flow from 0 and discharged as hot air outside the equipment for heating. In this type of combustion device, when the fuel supply amount is adjusted by changing the driving frequency and applied voltage of the pump 23, the primary air also increases / decreases accordingly, and the combustion amount is maintained while the ratio of fuel and combustion air is kept substantially constant. Can be changed.

[0003]

However, the combustion device having such a structure is used as a vaporization element that diffuses and vaporizes the fuel when using a fuel containing a large amount of high boiling point components such as a deteriorated fuel that has been left for a long time and oxidized. There is a problem that the tar component is generated, the vaporization element is clogged and vaporization failure occurs, and the combustion amount is reduced and abnormal combustion occurs.

That is, in this type of combustion apparatus, during combustion, the fuel supplied from the fuel supply port to the vaporization section 24 by the fuel supply means such as a pump moves and diffuses through the opening of the vaporization element provided in the vaporization section. The vaporized fuel gas is vaporized while being gradually heated by the heater or combustion heat, and the vaporized fuel gas is combusted in the burner portion 27 from the communicating nozzle portion 25. At this time, the vaporization portion 24 is cooled by the supplied fuel or the heater or A temperature difference occurs due to the configuration of the conduction of combustion heat, and tar is less likely to be generated in a low temperature portion, and tar is easily generated in a higher temperature portion. However, since the vaporization element provided in the vaporization section 24 is formed of a porous body and has a constant aperture ratio, the pores in the vaporization element are clogged with tar at a portion where a large amount of tar is produced.

When the vaporization element is clogged with tar as described above, the flow path resistance in the vaporization section increases, and the resistance reduces the amount of fuel supplied from the pump. Along with the decrease, the amount of combustion air sucked by the jet of the fuel gas is reduced, so that the ratio of the fuel and the air amount is changed, which causes deterioration of the combustion state. The pores of the vaporizing element also cause the fuel that had been widely diffused and vaporized in the vaporizing element to be clogged with the vaporizing element, which suppresses the diffusion and vaporizes locally, causing irregular pulsating vaporization. Was becoming.

The present invention is intended to solve the above problems, and an object thereof is to suppress clogging of a vaporization element due to tar, prevent vaporization failure, and maintain a good combustion state for a long period of time.

[0007]

In order to achieve the above-mentioned object, the present invention aims to achieve the above object by vaporizing a fuel, a heater for heating the vaporizing chamber, and a vaporized fuel gas which is communicated with the vaporizing chamber to eject the vaporized fuel gas. A nozzle section and a burner section for burning the fuel gas ejected from the nozzle section are provided, and the vaporization chamber is provided with a fuel supply port at the end opposite to the nozzle communication end, and the inside of the inorganic porous body is provided. A vaporization element is provided, and the vaporization element is configured to have a large opening ratio or pore diameter on the nozzle side and a small opening ratio or pore diameter on the fuel supply port side.

Alternatively, the aperture ratio or the pore diameter of the vaporization element is proportionally increased from the higher temperature to the smaller according to the temperature gradient of the vaporization chamber.

Further, the vaporization element is composed of a combination of a plurality of inorganic porous bodies having different opening ratios or pore diameters, or one inorganic porous body having different opening ratios or pore diameters.

[0010]

According to the present invention, as in the first and second configurations, by reducing the aperture ratio or the pore diameter of the vaporization element located on the fuel supply port side cooled by the fuel, the movement and diffusion of the fuel is promoted and the vaporization is performed. Even if tar is generated by increasing the aperture ratio or pore size of the vaporization element located on the side of the nozzle that is heated by the heater or the heat of combustion and has a high temperature, the aperture ratio or pore size is extremely reduced. This can be suppressed, and a large reduction in the combustion amount can be prevented.

Further, in the case where the vaporizing element is composed of a plurality of inorganic porous materials, by replacing the vaporizing element which is clogged with tar, it is possible to exert the above-mentioned combustion amount reduction preventing effect for a longer term and effectively. it can.

Further, in the case where the vaporizing elements having different aperture ratios or pore diameters are integrally molded, compared to the case where a plurality of vaporizing elements having different aperture ratios or pore diameters are used, the vaporization elements at the joints are different from each other. The fuel can be smoothly diffused and moved, and a stable vaporized state can be obtained.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 and FIG. 2, reference numeral 1 denotes a vaporization portion, which is provided with a circular burner receiving seat 2 on the upper portion thereof, and which is located substantially at the center of the burner receiving seat 2 and which is connected to the burner receiving seat 2 by a rib portion 11. 3 is arranged, and an opening 4 into which combustion air flows is opened between the burner receiving seat 2 and the nozzle portion 3. 6 is a vaporization chamber, one end of which is connected to the nozzle portion 3 through the communication port 5.
And extends in the radial direction and has a fuel supply port 8 at the other end. A vaporization element 7a of an inorganic porous body having a small opening rate is provided on the fuel supply port 8 side in the vaporization chamber 6, and a vaporization element 7b of an inorganic porous body having a large opening rate or a large pore size is provided on the nozzle section 3 side.
Is provided. Reference numeral 10 is a temperature detecting means for detecting the temperature of the vaporizer 1, and 9 is a heater, which is provided along the back surface of the burner receiving seat 2 excluding the vaporization chamber 6. Reference numeral 12 is a mixing tube located above the nozzle portion 3 and placed on the burner receiving seat 2, 13 is a burner portion having a large number of flame holes 14 formed in the lower peripheral wall, 16
Is a burner ring 17 arranged so as to cover the flame hole portion 14,
Is a heat receiving portion provided on the burner receiving seat 2.

In the above structure, the fuel sent from the fuel supply port 8 to the vaporization chamber 6 is vaporized in the vaporization chamber 6 maintained at a predetermined temperature by the heater 9 and the temperature detecting means 10, and becomes fuel gas to become a nozzle. Eject from part 3. Fuel gas is nozzle 3
When ejected from the opening 4 due to the ejector effect
Next air is sucked and mixed with the fuel gas in the mixing pipe 12, flows into the burner portion 13 and burns in the flame hole portion 14.

When combustion is started, the flame 15 burned in the flame hole portion 14 heats the heat receiving portion 17, and the conduction heat from the flame hole portion 14 is transferred to the burner receiving seat 2 so that the carburetor 1 has a temperature higher than a predetermined temperature. Then, the controller (not shown) stops energizing the heater 9 based on a signal from the temperature detecting means 10, and thereafter the carburetor 1 is maintained at a constant temperature only by the combustion heat.

At the time of combustion, the vaporization chamber 6 is
The vicinity of the communication port 5 which is the outlet of the fuel gas is heated via the rib portion 11 connected to the burner receiving seat 2, and the vicinity of the central portion in the longitudinal direction is directly transferred with heat from the burner receiving seat 2 from above, and the vaporization element 7 is It is heated by conduction heat from the wall surface of the vaporization chamber 6. Further, the fuel supply port 8 side of the vaporization element 7 is cooled by the supplied fuel. Therefore, the vaporization element 7 is heated so that the temperature of the vaporization element 7 is low on the side of the fuel supply port 8 and high on the side of the nozzle portion 3 as shown in FIG.

During the process of vaporization of the fuel in the vaporization chamber 6, the fuel supplied from the fuel supply port 8 into the vaporization chamber 6 gradually moves while moving and diffusing in the pores of the vaporizing element 7 having pores toward the outlet. Is heated and vaporized to become fuel gas, which is ejected from the nozzle portion 3 through the communication port 5. At this time, if the aperture ratio or pore diameter of the vaporization element 7 is large and uniform, the moving speed of the fuel slows down and vaporizes locally in the vaporization element 7 without sufficiently diffusing to generate tar. Further, the fuel intermittently supplied from the pump is locally vaporized, which causes irregular pulsating vaporization. On the other hand, vaporization element 7
If the opening ratio or the pore diameter of the fuel is small and uniform, the fuel supplied from the fuel supply port 8 has a high moving speed and is vaporized in the downstream portion (a portion near the nozzle portion) having a high temperature. Since the rate or pore diameter is small, a small amount of tar causes the opening of the vaporization element 7 to be clogged, and the passage resistance increases, so that the fuel supply capacity of the pump is reduced and the combustion amount is reduced.

According to the structure of this embodiment, the vaporization element 7a located on the fuel supply port 8 side of the vaporization chamber 6 has a small aperture ratio or a small pore diameter, and the vaporization element 7b located on the nozzle portion 3 side has an aperture ratio of 7 or less. Alternatively, by increasing the pore size, the fuel supplied from the fuel supply port 8 diffuses at a high speed in the vaporization element 7a having a small opening ratio or a small pore size and moves to the downstream side. Then, the vaporization is promoted in the vaporization element 7b where the temperature on the downstream side is high and the aperture ratio or the pore diameter is large, so that the communication portion 5
The vaporization is completed by the time, and the gas is ejected from the nozzle portion 3.
At this time, when most of the vaporization element 7b having a large opening ratio or pore diameter is vaporized and fuel having a high boiling point component is used, tar is generated in the same portion, but the opening ratio or pore diameter is large. Therefore, even if tar is generated, the entire opening is less likely to be clogged, and the time until the combustion amount is significantly reduced can be lengthened. Further, the fuel intermittently supplied from the pump is sufficiently diffused in the vaporization element 7a, so that the pulsating vaporization can be suppressed.

FIG. 3 shows another embodiment of the vaporization element 7. The vaporization element 7 has a portion 7a having a small opening ratio or a small pore diameter on the fuel supply port 8 side and an opening ratio or a fine pore diameter on the nozzle portion 3 side. By integrally molding with the large portion 7b, the opening between the vaporization elements 7a and 7b can be communicated, and the diffusion and movement of the fuel can be smoothed to obtain a stable vaporization state.

FIG. 5 shows still another embodiment of the vaporizing element,
In the vaporization element 7, the aperture ratio or pore diameter of the inorganic porous material is changed so as to be proportional to the temperature distribution of the vaporization chamber 6. That is, in the temperature distribution of the vaporization chamber 6, as shown in FIG. 4, the temperature rises rapidly from the fuel supply port 8 side toward the nozzle part 3 side, and the temperature gradient becomes gentle as it approaches the nozzle part 3. The vaporization element 7 has its aperture ratio or pore diameter set so that the nozzle portion 3 side becomes large in accordance with the temperature gradient of the entire vaporization chamber. As a result, the function and effect described in the above embodiment can be more effectively exhibited.

[0021]

As described above, in the combustion apparatus of the present invention, the fuel supply port is provided at the end of the vaporizing chamber opposite to the communicating end of the nozzle, and the vaporizing element of the inorganic porous material is provided inside. Since the vaporization element has a small aperture ratio or pore diameter of the vaporization element located on the side of the fuel supply port that is cooled by the fuel, it is possible to promote the migration and diffusion of the fuel and to promote the vaporization, and also the heater. Since the vaporization element located on the side of the nozzle that is heated by the heat of combustion and has a high temperature has a large aperture ratio or pore diameter, it is possible to prevent the aperture ratio or pore diameter from extremely decreasing even if tar is generated. Therefore, it is possible to significantly reduce the combustion amount and prevent abnormal combustion.

Further, in the case where the aperture ratio or the pore diameter of the vaporization element is configured to be proportionally large to small from the higher temperature depending on the temperature gradient of the vaporization chamber, the above effect is more effective. It is exhibited, and the effect of promoting vaporization and preventing reduction of the combustion amount is improved.

Further, in the case where the vaporizing element is composed of a plurality of inorganic porous materials, by replacing the vaporizing element that is clogged with tar, it is possible to exert the above-mentioned combustion amount reduction preventing effect for a longer term and effectively. it can.

Further, in the case where the vaporizing elements having different aperture ratios or pore diameters are integrally molded, compared with the case where a plurality of vaporizing elements having different aperture ratios or pore diameters are used, the joint portion of each vaporizing element is different. The fuel can be smoothly diffused and moved, and a stable vaporized state can be obtained.

[Brief description of drawings]

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

FIG. 2 is a plan view of a burner seat of the combustion device.

FIG. 3 is a sectional view of a combustion apparatus showing another embodiment of the present invention.

FIG. 4 is a temperature characteristic diagram showing a temperature gradient in the vaporization chamber of the combustion apparatus of the present invention.

FIG. 5 is a sectional view of a combustion device showing still another embodiment of the present invention.

FIG. 6 is a sectional view of a conventional combustion device.

[Explanation of symbols]

 1 Vaporizer 2 Burner receiving seat 3 Nozzle section 6 Vaporizing chamber 7 Vaporizing element 7a Vaporizing element with a small opening rate 7b Vaporizing element with a large opening rate 8 Fuel supply port 9 Heater 10 Temperature detecting section 13 Burner section

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takehiko Shigeoka 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. A vaporization chamber for vaporizing a fuel, a heater for heating the vaporization chamber, a nozzle portion communicating with the vaporization chamber for ejecting vaporized fuel gas, and a fuel gas ejected from the nozzle portion for combustion. A burner portion, the vaporization chamber is provided with a fuel supply port at the end opposite to the nozzle communication end, and a vaporization element made of an inorganic porous material is disposed inside the vaporization chamber. A combustion device in which the opening ratio or the pore size is large and the opening ratio or the pore size on the fuel supply port side is small. 2. A vaporization chamber for vaporizing a fuel, a heater for heating the vaporization chamber, a nozzle portion communicating with the vaporization chamber for ejecting vaporized fuel gas, and a fuel gas ejected from the nozzle portion for combustion. A burner portion, the vaporization chamber is provided with a fuel supply port at the end opposite to the nozzle communication end, and a vaporization element made of an inorganic porous material is disposed inside, and the vaporization element has an opening ratio or A combustion device in which the pore size is proportionally increased from higher to lower depending on the temperature gradient in the vaporization chamber. 3. A vaporization element comprising a combination of a plurality of inorganic porous bodies having different aperture ratios or pore diameters.
Combustion device as described. 4. The combustion device according to claim 1, wherein the vaporization element is formed by changing the aperture ratio or the pore diameter of one inorganic porous body.