JPH02101306A - Combustion apparatus - Google Patents

Abstract

PURPOSE:To reduced CO concentration, prevent the property of flue gas from deteriorating, improve the combustibility, expand the control range of combustion rate, and improve the safety in a combustion apparatus for a household heater, by providing catalysts inside an inner flame drum. CONSTITUTION:Catalysts 22 of oxides of platinum, etc. are arranged on the internal circumferential surface and the back of top cover of an inner flame drum 6. In this constitution, a thermal draft is produced as high temperature combustion gas rises inside a combustion chamber 8, and combustion air is supplied from air nozzles 11 on the inner flame drum 6 and an outer flame drum 7, and from penetration holes 17 on a red-heat element 16 into the combustion chamber 8. At this time, a portion of unburned gas containing a large amount of CO flows into the inner flame drum 6, and contacts with the catalysts 22 to be oxidized, so that the CO concentration is reduced. Therefore, when the combustion rate is lowered, the CO concentration which is emitted from the air nozzles above the flame f2 to the atmosphere is reduced. Thus, a decrease in the CO concentration and the expansion of control range of combustion rate can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a combustion device used for home heating and the like.

BACKGROUND OF THE INVENTION Conventionally, as a combustion device of this type, there has been a suction vaporization type combustion device used in kerosene stoves, etc., and this was generally of the type shown in FIG. In FIG. 4, reference numeral 1 denotes a lamp wick, which is set between an inner wick tube 2 and an outer wick tube 3 so as to be vertically movable.

The upper ends of the inner core tube 2 and the outer core tube 3 form an inner flame tray 4 and an outer flame tray 5, respectively, on which an inner flame tube 6 and an outer flame tube 7 are placed. During combustion, the tip of the wick 1 is exposed in a combustion chamber 8 formed between an inner flame tube 6 and an outer flame tube 7, where the combustion is vaporized. Reference numeral 9 denotes an outer cylinder, and the inner flame cylinder 6, the outer flame cylinder 7, and the outer cylinder 9 are arranged approximately concentrically in order from the inside, and are integrated by a fixing pin 10. Reference numeral 11 indicates a large number of air holes provided in the inner flame tube 6 and the outer flame tube 7. Reference numeral 12 denotes an inner flame tube top plate that closes the upper end opening of the inner flame tube 6, and has a ventilation hole 13 communicating upward from the inside of the inner flame tube 6. 14 is a flame expansion plate placed on the top plate 12 of the inner flame tube. At the upper end of the outer cylinder 9 there is a constriction part 15.
Furthermore, a red-hot part 16 is formed in the outer flame cylinder 7 above the constricted part 15, and a large through-hole 17 is provided. Reference numeral 18 denotes a transparent tube made of a transparent material such as glass, and is placed on top of the outer tube 9. A top frame 19 is placed on the upper end of the red-hot part 16 so as to close the upper end of the air passage 20 between the red-hot part 16 and the transparent cylinder 18, and fixes the transparent cylinder 18.

Reference numeral 21 denotes a current plate set inside the lower part of the inner flame cylinder 6.

In the above configuration, when the lamp wick 1 is ignited, combustion starts,
High-temperature combustion gas from combustion rises in the combustion chamber 8, creating a thermal draft, and the air necessary for combustion flows into the inner flame tube 6,
The combustion is continued by being supplied into the combustion chamber 8 through the air hole 11 of the outer flame tube 7 and the through hole 17 of the red-hot part 16, making the red-hot part 16 red-hot and using it as radiant heat for heating and the like.

Problems to be Solved by the Invention In normal strong combustion, as shown in FIG. 4, a secondary flame f1 is formed above the inner flame tube 6 and the outer flame tube 7, and the unburned components rise inside the combustion chamber 8. It shows good exhaust gas characteristics because it completely burns the gas. However, when the exposed height of the lamp wick 1 is lowered to reduce the amount of combustion, the flame descends into the combustion chamber 8 and is formed as shown at f2.

Conventionally, under such conditions, exhaust gas characteristics, especially CO/CO
2 was rapidly deteriorating. In order to solve this problem, a catalyst body 26 is installed in the exterior member 25 above the combustion tube 24 as shown in FIG.
Measures to reduce O are being used, but it is difficult to treat all the combustion gas with this method, and
During weak combustion, the temperature of the catalytic body decreases, so the catalytic effect was not satisfactory.

As a result of measuring the exhaust gas inside the combustion apparatus, it has become clear that the main cause of the phenomenon in which the exhaust gas characteristics deteriorate during weak combustion is the flow inside the inner flame cylinder 6 as described above. Figure 6 shows the results of measuring the CO distribution in the height direction of the A-A'' line (inside the inner flame tube 6) of the combustion device shown in Figure 4. It shows a very high value.During strong twist firing, even if a large amount of CO exists inside the inner flame tube 6, it passes through the flame fl and is almost completely combusted, resulting in good exhaust gas characteristics, but during weak combustion is emitted directly into the atmosphere without passing through this high-concentration CO flame zone.

From the above, it is clear that there is a flow as shown by the broken line a leaking from the combustion chamber 8 into the inner flame tube 6 as shown in FIG. 13 and directly discharged into the atmosphere from the air hole 11 above the flame f2, the Go/CO□ characteristics are drastically deteriorated. Therefore, the combustion amount could only be adjusted within the range where the flame f1 was formed above the combustion chamber.

Means for Solving the Problems In order to solve the above problems, in the combustion apparatus of the present invention, a catalyst body is provided inside the inner flame cylinder.

Effect of the present invention With the above-described configuration, the unburned gas containing a large amount of CO that has flowed inside the inner flame cylinder is oxidized by the catalyst body, and the CO
Significantly reduces O. Therefore, CO released from the inside of the inner flame cylinder into the atmosphere is significantly suppressed, and GO/C (h characteristics) can be significantly improved.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In FIG. 1, reference numeral 1 denotes a lamp wick, which is a fuel vaporizing section, and is set between an inner wick tube 2 and an outer wick tube 3 so as to be vertically movable. The upper ends of the inner core cylinder 2 and the outer core cylinder 3 are an inner fire pan 4 and an outer fire pan 5, respectively.
, and an inner flame tube 6 and an outer flame tube 7 are placed thereon. During combustion, the tip of the wick 1 is exposed in a combustion chamber 8 formed between an inner flame tube 6 and an outer flame tube 7, where the fuel is vaporized. Reference numeral 9 denotes an outer cylinder, and the inner flame cylinder 6, outer flame cylinder 7, and outer cylinder 9 are arranged approximately concentrically in order from the inside, and are integrated by a fixing pin 10. Reference numeral 11 indicates a large number of air holes provided in the inner flame tube 6 and the outer flame tube 7. Reference numeral 12 denotes an inner flame tube top plate that closes the upper end opening of the inner flame tube 6, and has a ventilation hole 13 communicating upward from the inside of the inner flame tube 6. 14 is a flame expansion plate placed on the top plate 12 of the inner flame tube. A constriction part 15 is formed at the upper end of the outer flame tube 9, and a glowing part 16 is formed in the outer flame tube 7 above the constriction part 15, and a large through hole 1 is formed in the outer flame tube 7 above the constriction part 15.
7 is provided. Reference numeral 18 denotes a transmission tube made of a transparent material such as glass, which is placed on the outer flame tube 9. A top frame 19 is placed on the upper end of the red-hot part 16 so as to close the upper end of the air passage 20 between the red-hot part 16 and the transparent cylinder 18, and fixes the transparent cylinder 18. Reference numeral 21 denotes a current plate installed inside the lower part of the inner flame cylinder 6. Reference numeral 22 denotes an oxidation catalyst such as platinum, which is set on the inner periphery and upper surface of the inner flame cylinder 6. 23 is an air introduction path.

In the above configuration, when the lamp wick 1 is ignited, combustion starts, and high temperature combustion gas due to combustion rises in the combustion chamber 8, creating a thermal draft, and the air necessary for combustion is transferred to the inner flame tube 6 and the outer flame tube 7. The fuel is supplied to the combustion chamber 8 through the hole 11 and the through hole 17 of the red-hot section 16, and combustion continues. At this time, a portion of the unburned gas containing a large amount of CO flows into the inner flame tube 6. In the conventional example, when the combustion amount is reduced and the flame descends into the combustion chamber 8 like f2, this CO is directly released into the atmosphere from the air hole above the flame f2, so the exhaust gas characteristics, especially CO/C (h
The characteristics were rapidly deteriorating. However, in this embodiment, since the catalyst body 22 is set inside the inner flame cylinder 6, the CO flowing inside the inner flame cylinder 6 is oxidized by contacting or passing through the catalyst body, and the CO concentration decreases. significantly reduced. Therefore, even if the combustion amount is reduced and the flame f2 descends into the combustion chamber 8, the CO concentration in the combustion gas released directly into the atmosphere from the air hole above the flame f2 is low, and the CO/CO,
Characteristics can be significantly improved. In this embodiment, the catalyst body 22 is provided on the inner periphery and upper surface of the inner flame cylinder 6, so that the catalyst body 22 is kept at a relatively high temperature. Furthermore, the unburnt gas rising near the inner wall of the inner flame cylinder 6 as indicated by the arrow comes into contact with the catalyst body 22 frequently. The effect is further enhanced if the catalyst body 22 is formed into a corrugated shape. Further, unburned gas that has passed through the catalyst body 22 as indicated by arrow C also passes through the catalyst body again at the upper part and is released into the atmosphere. In this way, it is possible to achieve a significant reduction in CO by effectively installing the catalyst body 22, but there are cases where the catalyst body 22 can only be installed in some areas due to balance with other combustion characteristics or design issues. However, some effect can be obtained. Figure 2 shows CO/C versus combustion amount for this example.
These are the results of measuring O□ characteristics. For comparison, the results for the conventional example shown in Fig. 6 are also shown, and compared to the conventional example, the C
It can be seen that the o/Go□ characteristics are significantly improved.

Particularly during weak combustion, in the conventional example, the catalyst temperature decreases, so the CO reduction effect is not sufficient. On the other hand, in this embodiment, since the catalyst body 22 is provided inside the inner flame tube 6, the catalyst temperature is also maintained at a high temperature, so that a sufficient effect is exhibited. Third
The figure shows another embodiment of the present invention, in which the catalyst body 2
2 are provided in at least one layer in the height direction inside the inner flame cylinder 6. According to this configuration, the unburned gas flowing from below the inner flame tube 6 as shown by the arrow d passes through many layers of the catalyst body 22, and as in the embodiment shown in FIG.
It is possible to reduce the concentration and improve CO/GO□ characteristics.

Effects of the Invention As is clear from the above explanation, according to the present invention, by providing a catalyst body inside the inner flame cylinder, CO flowing into the inner flame cylinder is oxidized and the CO concentration is significantly reduced. It is possible to prevent a sudden deterioration of exhaust gas characteristics, to have good combustion characteristics, a wide range of combustion amount adjustment, and to obtain a safe combustion device.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part of a combustion device according to an embodiment of the present invention, FIG. 2 is a characteristic diagram showing the effects of the same device, and FIG. 4 is a sectional view of a main part of a conventional combustion device, FIG. 5 is a sectional view of a main part of another conventional example, and FIG. 6 is a characteristic diagram of the conventional example. 1...Fuel supply section, 6...Inner flame cylinder, 7
...Outer flame tube, 8... Combustion chamber, 9...
... Outer cylinder, 11 ... Air hole, 22 ...
・Catalyst body. ! = 7 ・・− 8・・− Yuka compensation chamber inner flame tube outer flame tube twist l

Claims (1)

[Claims] an outer flame tube having a large number of air holes, an inner flame tube having a large number of air holes arranged inside the outer flame tube, an outer flame tube located outside the outer flame tube, and the outer flame tube. A combustion device comprising: a fuel supply section set at a lower end of a combustion chamber formed between a cylinder and the inner flame tube; and a catalyst body disposed inside the inner flame tube.