JPH0672681B2 - Combustion device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device used for household heating or the like.

2. Description of the Related Art Conventionally, as this type of combustion apparatus, there is a suction vaporization type combustion apparatus used in petroleum stoves and the like, but as shown in FIG. 7, this is an internal flame having a large number of air holes 11. The tip of the wick 1 which is a fuel supply section is exposed in a combustion chamber 8 formed between an inner flame cylinder 6 which is a body and an outer flame cylinder 7 which is an outer flame body to vaporize and burn the fuel. Normally, the outer flame cylinder 7 forms a red heat portion 16 having a through hole 17 having a large opening area above the narrowed portion 15 of the outer cylinder a9 which is an outer body, and the fuel vaporized from the wick 1 and the through hole 17 are formed. The air introduced into the combustion chamber 8 from the above was mixed and burned to red heat the red heating section 16 to obtain radiant heat.

Problems to be Solved by the Invention However, the above-described configuration has the following problems.

In normal strong combustion, the inner flame cylinder 6 and the outer flame cylinder 7 as shown in FIG.
A secondary flame f ₁ is formed between them, and the unburned components that have risen in the combustion chamber 8 are completely burned, so that good characteristics are exhibited. However, when the exposed height of the wick 1 is reduced to reduce the amount of combustion, the flame falls into the combustion chamber 8 and forms like f ₂ .
In this case, the flame f ₃ formed in the air hole 11 and the through hole 17 of the inner flame cylinder is not formed above the flame f ₂ . Conventionally, in such a state, exhaust gas characteristics, particularly CO / CO _2, have deteriorated sharply. The cause of this has not been clarified in the past, but the following results have revealed that the main factor is the air flow inside the inner flame cylinder 6.

FIG. 8 is a line AA ′ of the conventional combustion apparatus of FIG. 7 (that is, the air passage 20 between the outer cylinder a9 or the outer cylinder b18 and the outer flame cylinder 7).
And the distribution of CO in the height direction at the position of the line BB '(that is, the inside of the inner flame cylinder 6) at the time of strong and weak combustion. A
At the position of -A 'line, CO is generated at the throttle part 15 or more of the outer cylinder 9 during strong combustion.
The concentration rapidly increases, reaches the maximum in the middle upper part, and decreases again near the upper end, but shows a high value of 500 ppm or more. However, during strong combustion, the flame f _{1 is used} for almost complete combustion, so the exhaust gas characteristics are good. The same behavior is exhibited during weak combustion, but the CO concentration is low, around 250 ppm near the upper end. At the position of the line BB, the same behavior is exhibited during strong combustion and weak combustion,
The CO concentration increases toward the top, and even in the case of weak combustion near the top, 10
It shows a very high value of over 00ppm.

From the above results, the flow of air and exhaust gas in the combustion device is as follows. That is, as shown in FIG. 7, the main flow is indicated by a black arrow, but in addition to that, there is a flow indicated by a broken arrow. That is, the exhaust gas in an incompletely combusted state is a flow a leaking from the combustion chamber 8 to the air passage 20 and a flow b leaking from the combustion chamber 8 into the inner flame cylinder 6. Of these, the flow a has a large opening ratio of the through holes 17 of the red heat section 16 and therefore the combustion chamber 8
Since it easily re-introduces into the inside and is burned with the flame f ₂ , CO shows a low value near the upper end of the outer flame cylinder during weak combustion. However, since the flow b has a small air hole 11 in the inner flame cylinder 6 and a large resistance, it is difficult to reflow into the combustion chamber 8, and CO shows a high value near the upper end of the inner flame cylinder 6 even during weak combustion. Therefore, at the time of weak combustion, if the flame falls into the combustion chamber 8 like f ₂ and no flame is formed above it, the air holes in the upper part of the inner flame tube 6
Exhaust gas containing a high concentration of CO is directly emitted into the atmosphere from 11 and the vent hole 13. It is clear that the main cause of the rapid deterioration of CO / CO ₂ during weak combustion is that the exhaust gas containing high concentration of CO that leaks into the inner flame cylinder 6 is directly discharged into the atmosphere. became.

Therefore, in order to improve CO / CO ₂ during weak combustion, high concentration
It is necessary to prevent the exhaust gas containing CO from being released directly into the atmosphere. Therefore, the height of the combustion chamber 8 is lowered, the combustion load in the combustion chamber 8 is reduced, and the combustion amount is reduced. Even in such a case, the flame was formed above the combustion chamber 8. However, in this case, there are problems such that the area of the red heat portion 16 becomes small, the red heat temperature becomes low during strong combustion, and red heat unevenness occurs. Further, when the combustion amount was further reduced, the flame eventually fell into the combustion chamber 8, and the above-mentioned phenomenon appeared, and the CO / CO ₂ characteristics deteriorated.

The present invention solves such a conventional problem, and an object of the present invention is to obtain a combustion device having good combustion characteristics and a large combustion amount adjustment range by suppressing a sharp deterioration of combustion characteristics during weak combustion. .

Means for Solving the Problems In order to solve the above problems, in the combustion apparatus of the present invention, the internal flame body is disposed inside the inner flame body and is located above the position facing the fuel supply portion. A control fluid that forms a control flow area between the control fluid and the inner flame body, and a plate portion that is provided in the control flow area between the control fluid and the internal flame body. There is a communication port that connects the restricted area.

Effect The present invention has the above-described configuration to prevent outflow of unburned gas to the air introduction path, introduces air from the air introduction path to the restricted flow area, mixes with the unburned gas, and burns from the air holes of the inner flame body. By supplying it to the chamber and efficiently burning it, it is possible to burn it without disturbing the air balance on the inner flame side and the outer flame side.

Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a cylindrical wick which is a fuel supply unit, and is vertically movable between a core inner cylinder 2 which is a core inner body and a core outer cylinder 3 which is an outer core body. The upper ends of the inner core tube 2 and the outer core tube 3 form an inner fire tray 4 and an outer fire tray 5, respectively.
An inner flame cylinder 6 that is an inner flame body and an outer flame cylinder 7 that is an outer flame body are placed. At the time of combustion, the tip of the wick 1 is exposed in the combustion chamber 8 formed between the inner flame cylinder 6 and the outer flame cylinder 7, and the fuel is vaporized there. Reference numeral 9 denotes an outer cylinder a which is an outer body a, and the inner flame cylinder 6, the outer flame cylinder 7, and the outer cylinder a9 are sequentially arranged from the inside in a substantially concentric circle shape, and are integrated by a fixing pin 10. Reference numeral 11 denotes air holes provided in the inner flame cylinder 6 and the outer flame cylinder 7. 12
Is an inner-flame cylinder top plate that closes the upper end opening of the inner-flame cylinder 6 and has a vent hole 13 that communicates from the inside of the inner-flame cylinder 6 to the upper side. Reference numeral 14 is a flame spreading plate placed on the inner flame cylinder top plate 12. A red heat section 16 is formed in the outer flame tube 7 above the throttle section 15 of the outer tube 9, and a through hole 17 having a large opening is provided. An outer cylinder b, which is an outer body b made of a transparent material such as glass, is placed on the outer cylinder a9. 19 is the top frame, the red heat part 15 and the outer cylinder
It is placed on the upper end of the red heat section 15 so as to shield the upper end of the air passage 20 between the b19 and fixes the outer cylinder b18. Reference numeral 21 denotes a flow restricting cylinder, which is a control fluid installed inside the inner flame cylinder 6, and is located above the position facing the wick 1 and has a flow restricting area between the inner flame cylinder 6 and the inner flame cylinder 6.
Is formed. Restriction area 22 between restriction tube 21 and inner flame cylinder 6
Is provided with a plate portion 21a that is horizontally installed. 23 is an air introduction path. Reference numeral 24 is a communication port provided in the flow control cylinder 21 so as to connect the flow control area 22 and the air introduction path 23.

In the above configuration, when the wick 1 is ignited, combustion starts,
A high temperature combustion gas generated by combustion rises in the combustion chamber 8 to generate a thermal draft, and the air required for combustion is generated in the inner flame cylinder 6,
The combustion is continued by being supplied into the combustion chamber 8 through the air holes 11 of the outer flame cylinder 7 and the through holes 17 of the red heat section 16, and during strong combustion, a flame fr is formed as shown in FIG. Looking at the flow of combustion exhaust gas and air at this time, the flow in the air passage 20 is almost the same as in the conventional example shown in FIG. The air supplied from the inner side of the inner flame cylinder 6 is divided into a white arrow (a) supplied from below the flow control cylinder 21 to the vicinity of the wick 1 and a white arrow b rising in the air introduction path 23. The flow of the white arrow b reaches the upper side of the inner flame cylinder and is supplied to the combustion chamber 8 and the upper side thereof through the air holes 11 and the vent holes 13 as shown by the white arrow c. Further, a part of the air flows down to the restriction region 22 as indicated by a white arrow d, and is also supplied to the combustion chamber 8 from the air holes 11 located relatively below. Further, the fuel vaporized by the flow of the white arrow a becomes a mixed gas with air and mainly rises in the combustion chamber 8 as shown by the black arrow e. However, the flow of white air in the air introduction path 23
Due to this, a negative pressure is created in the restricted area 22, so that part of the mixed gas flows into the restricted area 22 as indicated by the black arrow f and rises. Therefore, the uncontrolled gas fills the restricted area 22. On the other hand, the control cylinder 21
Since the communication port 24 is provided at, a part of the flow of the white arrow b rising in the air introduction passage 23 flows into the restricted flow region 22 where negative pressure is obtained as shown by the white arrow g. Therefore, the unburned gas flowing in from the combustion chamber 8 and the clean air flowing in from the air introduction passage 23 are mixed in the restricted flow area 22, and the air enters from the air hole 11 of the inner flame cylinder 6 into the combustion chamber 8 as indicated by a black arrow h. And is burned over a wide range of the inner flame cylinder 6 so that the combustion is performed without breaking the air balance between the inner flame cylinder 6 side and the outer flame cylinder 7 side. Therefore, at the time of strong combustion, the red heat section 16 can also obtain a good red heat state. In addition, since a large amount of unburned gas flows into the restricted region 22 during strong combustion, part of the unburned gas flows out to the air introduction passage 23 as indicated by the broken line arrow (i). However, the outflow amount is small in view of the pressure balance between the restricted flow region 22 and the air introduction passage 23, and since it is diluted with a large amount of air, the air introduction passage 23 is kept in a clean state with low CO concentration. There is. Further, even if some unburned gas is present there, since it is burned by the flame fr above the combustion chamber 8, there is no problem in combustion characteristics.

Next, when the exposed height of the wick 1 is lowered and the combustion is weakened, the flame gradually falls into the combustion chamber 8 and becomes the flame fs. The flow in this case is the same as that in the case of strong combustion, but the amount of vaporized gas is greatly reduced, and therefore the amount of unburned gas flowing into the restricted region 22 is also reduced. Therefore, the mixing region of the air flow white arrows (d) and (g) with the unburned gas is lowered, and the middle and lower parts of the restricted flow region 22 become a good mixing region, and flame holding is formed in this part, and the inner flame tube 6 The wall surface is red-heated to promote combustion, and the flame fs formed above the wall completes the combustion. Further, since the unburned gas flowing into the restricted region 22 decreases during the weak combustion, there is almost no unburned gas flowing out to the air introduction passage 23 as indicated by the broken line arrow (i), and the air holes above the flame fs are discharged. The air discharged from the air vents 11 and the ventilation holes 13 can be kept in a clean state containing almost no CO, and the exhaust gas characteristic (CO / CO ₂ ) becomes good.
Further, the plate portion 21a allows the unburned gas to flow from the combustion chamber 8 to the flow control cylinder 21.
It is also possible to suppress merging with the air flow flowing upward through the air introduction path 23 surrounded by the flow control cylinder 21 via the lower end of the. Further, since the pressure in the restriction region 22 is lowered by the draft action of the combustion chamber 8, when the air flow flowing upward in the air introduction path 23 reaches the upper end of the restriction cylinder 21, it suddenly changes its direction toward the restriction region 22. It merges with the rising unburned gas in this restricted region 22 and promotes the flow into the combustion chamber 8.

That is, according to the present embodiment, the unburned gas and air are introduced into the restricted flow region 22 and mixed, and are efficiently supplied to the combustion chamber 8, so that the air balance between the inner flame cylinder 6 side and the outer flame cylinder 7 side is improved. Since it burns without breaking, a good red heat state can be obtained during strong combustion, and at the time of weak combustion, the state above the inner flame cylinder 6 contains almost no unburned gas, improving the exhaust gas characteristics. can do. Therefore, it is not necessary to reduce the combustion load in the combustion chamber 8 or the height of the combustion chamber in order to improve the exhaust gas characteristics during weak combustion as in the conventional case.

FIG. 3 shows the CC ′ line of the embodiment shown in FIG. 1 (control area 22).
And the CO concentration distribution at the line D-D '(air introduction path 23) are measured during weak combustion. High concentration of CO is detected from the lower end of the flow control cylinder 21 at the position C-C ', but it gradually becomes thinner near the center of the flow control cylinder 21 and is considerably diluted at the upper end of the inner flame cylinder 6, It can be seen that the upper side of the flame tube 6 is in a clean state with low CO concentration. It can be seen that the CO concentration is low over the entire region at the DD ′ line position inside the flow control cylinder 21, and clean air is supplied. From the above results, it can be seen that the exhaust gas characteristics above the inside of the inner flame cylinder 21 are significantly improved as compared with the conventional example.

FIG. 4 shows the results of measuring the combustion amount-CO / CO ₂ characteristics of this example and the conventional example. In the conventional example (dashed line), the CO / CO ₂ value sharply rises as the combustion amount decreases, and the exhaust gas characteristics deteriorate. However, in this example (solid line), the CO / CO ₂ value decreases even if the combustion amount decreases. Is maintained at 0.002 or less, the characteristics are significantly improved, and the effect of the present invention is clear.

In the embodiment of FIG. 1, a large number of small holes are provided on the wall surface of the flow control cylinder 21 as the communication port 24, but a vertically long hole or a horizontally long hole may be used. In addition, as shown in FIG.
A structure in which 25 or the like is provided may be a structure in which the cut-and-raised portion 26 is formed in the flow control cylinder 21 as shown in FIGS. Fig. 6a
In the case of, the cut-and-raised portion 26 is provided above the restricted flow area 22, and in the case of FIG. 6B, the cut-and-raised portion is provided below the air introduction passage 23. According to the structure of FIGS. 6a and 6b, the effect of preventing the outflow of unburned gas due to the flow of the broken arrow (i) shown in FIG. 2 is obtained. Further, although the cylindrical combustion device has been described in the above embodiments, it may have a flat plate structure.
Further, although the wick is used as the fuel supply section, a method of supplying a gaseous fuel or a method of supplying a liquid fuel vaporized by another vaporizing means may be used.

Effects of the Invention As described above, according to the combustion apparatus of the present invention, the following effects are obtained.

(1) A control fluid, which is disposed inside the inner flame body, is located above a position facing the fuel supply unit, and forms a control flow region between the inner flame body, and the control fluid and the inner flame body. A plate part is provided in the flow control area between and, and the control fluid is provided with a communication port that connects the flow control area and the air introduction path. Due to the air flow supplied to the control area, a negative pressure is generated in the control area, and unburned gas is introduced from the combustion chamber and air is introduced from the air introduction path. Therefore, the restricted flow area is filled with the mixed gas containing high concentration of CO, but this mixed gas rarely flows out to the air introduction path, and the clean air flow in the air introduction path and the mixed gas in the restricted flow area are separated, Clean air is supplied above the inner flame body.

(2) In the restricted flow region, unburned gas and air are mixed and uniformly resupplied into the combustion chamber, so that combustion can be efficiently promoted over a wide range of the inner flame body. Therefore, since the combustion can be performed without breaking the air balance on the outer flame side and the inner flame side, a good red heat state can be obtained during strong combustion.

(3) In the restricted area, unburned gas and air are mixed,
At the time of weak combustion, a good mixed state is formed at a certain height position of the inner flame body according to the amount of combustion, and flame holding is formed in the inner flame body air hole at that position, causing the inner flame body wall surface to glow red and burning. Promote. Further, combustion is completed by the flame formed above it.

(4) Outflow of unburned gas to the upper side of the inner flame body is blocked by the clean air flow supplied to the upper side of the inner flame body. Due to this shielding effect, the inside of the internal flame body contains almost no unburned gas.Therefore, even if the flame during weak combustion falls into the combustion chamber, high-concentration CO is directly emitted to the atmosphere from the air holes and vent holes above the internal flame body. It is not released.

Due to the above effects, it is possible to obtain a good red heat state during strong combustion and to greatly improve the exhaust gas characteristics during weak combustion, and to obtain a combustion device that has good combustion characteristics and a wide combustion adjustment range.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a combustion apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view showing a flow in the combustion apparatus, and FIG.
FIGS. 4 and 5 are characteristic diagrams for explaining the effect of the device, FIGS. 5 and 6 are perspective views and cross-sectional views of main parts of another embodiment of the present invention, and FIG. 7 is a conventional combustion device. FIG. 8 is a sectional view of a main part of FIG. 8 and FIG. 8 is a characteristic diagram of a conventional combustion device. 1 ... Fuel supply unit, 6 ... Inner flame body, 7 ... Outer flame body, 8 ...
… Combustion chamber, 9 …… Outer body, 11 …… Air hole, 21 …… Control fluid,
21a ... Plate part, 22 ... Restricted area, 23 ... Air introduction path, 24 ...
Communication port.

Claims (1)

[Claims] 1. An outer flame body having a large number of air holes, and an inner flame body having a large number of air holes arranged inside the outer flame body,
An outer body located outside the outer flame body, a fuel supply section set at the lower end of the combustion chamber formed between the outer flame body and the inner flame body, and disposed inside the inner flame body. And a control fluid located above the position facing the fuel supply section and forming a control flow area between the internal flame body and the control fluid provided laterally between the control fluid and the internal flame body. A combustion apparatus comprising: a plate portion, and at least a part of the control fluid, a communication port that communicates an air introduction path formed inside the control fluid with the control flow region.