JP3677853B2 - Burner equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a NOx reduction technology suitable for household combustion equipment.
[0002]
[Prior art]
Conventionally, this type of apparatus has a primary flame hole 12 partially opened on the upper surface of the Bunsen burner 11 and a secondary flame hole 14 as shown in Japanese Patent Publication No. 62-39329 in FIG. The configuration was covered with the combustion chamber 13. With this configuration, the flame at the maximum combustion forms a primary flame 15 on the primary flame hole 12 and a secondary flame 16 on the secondary flame hole 14. Further, at the time of the minimum combustion, the secondary flame 16a is formed in the wall of the primary combustion chamber 13 just outside the primary flame 15 on the primary flame hole 12 without forming the secondary flame 16 in the secondary flame hole 14. It was.
[0003]
[Problems to be solved by the invention]
However, in this type of two-stage combustion burner, the loads of the primary flame holes 12 and the secondary flame holes 14 are usually designed with values suitable for the maximum combustion amount. Therefore, at the maximum combustion amount, complete two-stage combustion can be formed by flame holding in each flame hole 12, 14.
[0004]
On the other hand, if the amount of combustion is reduced, the load on the secondary flame hole 14 becomes too low, so that the secondary flame 16 is difficult to be formed on the secondary flame hole 14 and does not become two-stage combustion, but on the primary flame hole 12. A normal premixed flame in which the secondary flame 16a is integrally formed outside the primary flame 15 becomes a NOx concentration in the exhaust gas.
[0005]
That is, when the combustion amount is reduced, there is a problem that the two-stage combustion is not performed and the low NOx combustion cannot be realized. Further, there is a problem that the primary flame 15 is easily lifted under a condition where the oxygen concentration in the atmosphere is lowered.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, a burner device according to the present invention includes a Bunsen burner having a primary flame hole on the upper surface, a box-shaped first combustion chamber that substantially airtightly surrounds the periphery of the primary flame shell, and an outer side thereof. A second combustion chamber having a second combustion chamber sharing the bottom of the first combustion chamber, and an upper portion of the second combustion chamber corresponding to a flame shape during maximum combustion of the Bunsen burner; The first combustion chamber is provided with a first secondary flame hole corresponding to the flame shape at the time of maximum combustion of the Bunsen burner at the upper part of the first combustion chamber.
[0007]
According to the above invention, at the time of maximum combustion, the secondary flame is formed on the secondary flame hole and becomes two-stage combustion. Further, at the time of the minimum combustion, the secondary flame is formed on the first combustion chamber flame hole, and even if one of the secondary flames moves, the secondary combustion is still performed. The primary flame in the first combustion chamber can achieve stable two-stage combustion by raising the temperature of the primary flame by heat radiation from the wall of the first combustion chamber, and good low NOx combustion can be achieved in the entire combustion range. .
[0008]
Further, by providing the bottom of the first combustion chamber in the vicinity of the primary flame hole, the bunsen burner 1 is heated, the fuel gas in the bunsen burner 1 expands, and the gas ejection speed from the primary flame hole increases. The increase in the ejection speed from the primary flame hole increases the degree of air suction of the Bunsen burner, so that the primary air area can be reduced and the combustion performance can be further improved by suppressing excess air during maximum combustion.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The present invention shares a Bunsen burner having a primary flame hole on the upper surface, a box-shaped first combustion chamber that surrounds the primary flame hole in a substantially airtight manner, and a bottom portion of the first combustion chamber on the outside. A second combustion chamber, a second secondary flame hole corresponding to a flame shape at the time of maximum combustion of the Bunsen burner, and an upper portion of the first combustion chamber. Is provided with a first secondary flame hole corresponding to the flame shape at the time of minimum combustion of the Bunsen burner.
[0010]
At the time of maximum combustion, the secondary flame is formed on the secondary flame hole and becomes two-stage combustion. Further, at the time of the minimum combustion, the secondary flame is formed on the first combustion chamber flame hole, and even if the position of the secondary flame moves, the secondary combustion is still performed. The primary flame in the first combustion chamber can achieve stable two-stage combustion by raising the temperature of the primary flame by the heat radiation from the wall of the second combustion chamber, and good low NOx combustion can be achieved in the entire combustion range. .
[0011]
Also, by providing the bottom of the first combustion chamber in the vicinity of the primary flame hole, the bunsen burner is heated, the fuel gas in the bunsen burner expands, and the gas ejection speed from the primary flame hole increases. The increase in the ejection speed from the primary flame hole increases the degree of air suction of the Bunsen burner, so that the primary air area can be reduced and the combustion performance can be further improved by suppressing excess air during maximum combustion.
[0012]
In addition, an auxiliary air hole penetrating the bottom of the first combustion chamber is provided.
In the low oxygen concentration state and the insufficient primary air amount, the primary flame is easily lifted regardless of the combustion amount. Therefore, by providing auxiliary air holes communicating with the outside air on the combustion chamber wall, the low oxygen concentration state and the primary air amount are provided. When there is a shortage, the primary flame can be stabilized by introducing combustion air from the auxiliary air holes.
[0013]
(Example 1)
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a configuration diagram of the hot air heater of the embodiment used in the present invention. The burner 1 has a primary flame hole 2, and the primary flame hole 2 is also on the upper surface or side surface of the burner 1. The primary flame hole 2 may have a shape having a long slit or a round hole. The opening of the primary flame hole 2 may be covered with a wire mesh.
[0014]
The first combustion chamber 3 accommodates the upper part of the burner 1 in a substantially airtight manner. The second combustion chamber 4 is covered with a combustion chamber unit 24 comprising combustion guides 6, 7 and 8. At the time of combustion, the blades 10 are rotated by driving the motor, and hot exhaust gas from the burner 1 and air are mixed to form hot air, which flows along the blade guide 17 by the suction force of the blades 10.
[0015]
The combustion guide 18 is a passage guide for heated hot air, the combustion chamber unit 24 is covered with an outer box 25, and the hot air flowing along the blade guide 17 is a hot air outlet provided in the outer box 25. 26 is blown out.
[0016]
Next, the structure of the 2nd combustion chamber 4, the 1st combustion chamber 3, and the burner 1 is demonstrated based on FIG.1, FIG.2, FIG.3. The first combustion chamber 3 has a first secondary flame hole 5 on the upper surface, and is configured to be almost airtight so as to cover a vicinity 29 (a portion surrounded by a broken line) of the primary flame hole 2 of the burner 1. Yes. The combustion chamber fixing portion 28 at the lower part of the first combustion chamber 3 is closely fixed to the burner 1 so as not to cover the primary hole 2 in the vicinity 29 of the primary flame hole 2 of the burner 1.
[0017]
Since the first combustion chamber 3 is heated by the radiant heat of the primary flame 19 of the burner 1, the combustion chamber fixing portion 28 is also heated and heated by heat conduction. Further, the vicinity 29 of the primary flame hole 2 is also directly heated by the primary flame 19.
[0018]
And in addition to the heat conduction of the combustion chamber fixing part 28, the heating of the vicinity part 29 is transferred to the whole burner 1, and the fuel gas in the burner 1 is heated and expanded as the temperature of the whole burner 1 rises. Therefore, when the fuel gas of the burner 1 expands and the specific gravity becomes light, the specific gravity difference with the external air increases, and the gas ejection speed from the primary flame hole 2 increases. Due to the increase in the gas ejection speed, the amount of primary air sucked from the primary air suction port 30 of the burner 1 increases.
[0019]
That is, the draft as a force for ejecting the fuel gas from the primary flame hole 2 is increased, and the suction amount of the primary air from the primary air suction port 30 is increased as compared with the case where the first combustion chamber 3 is not attached. Since the primary flame 19 is formed in the entire combustion range, this draft increase can be expected in all combustion states. Therefore, adjustment of the amount of air by a damper or the like of the primary air inlet 30 needs to be adjusted.
[0020]
Conventionally, the air intake rate at the time of minimum combustion is increased by a smaller ventilation resistance than at the time of maximum combustion in the burner 1, so the air excess rate at the time of maximum combustion is slightly reduced. It was covered with an excessively small state, if not enough. However, by installing the first combustion chamber 3, an increase in the draft described above can be expected, and the excess air ratio that must be reduced to reduce the excessive combustion performance for improving the low combustion performance at the time of maximum combustion is reduced. Good high combustion performance can be obtained.
[0021]
Further, the first combustion chamber 3 can also improve the combustion performance in the intermediate region. That is, in the first combustion chamber 3, the radiant heat of the primary flame 19 heats the first combustion chamber 3 to store heat at all intermediate combustion times below the maximum combustion time.
[0022]
The stored first combustion chamber 3 heats the burner 1 via the combustion chamber fixing portion 28 and reflects part of the radiant heat to raise the temperature of the primary flame 19. That is, the flame temperature of the primary flame 19 rises and the flame holding performance as the flame forming performance becomes stronger, the combustibility of the primary flame 19 is improved, and the combustion performance after the completion of combustion in the secondary flame 12 can be enhanced. .
[0023]
Thus, by providing the first combustion chamber 3, the draft of the flame cancels out the ventilation resistance in the burner 1, and the primary air suction port 30 is tightened up and down more than before by the remaining power, and the average is obtained in the entire combustion region. The inhalation rate of converted air can be taken.
[0024]
Next, the first combustion chamber flame hole load (the flame hole area ratio of the combustion amount in the first combustion chamber 3) is smaller than the primary flame hole load of the primary flame hole 2, and the secondary flame 20 The secondary flame hole load (the flame hole area ratio of the combustion amount combusted in the secondary flame hole 22) is formed to be equal to or larger than the first flame hole load 22.
[0025]
The height position L of the first combustion chamber 3 provided in the second combustion chamber 4 is set according to the maximum combustion amount of the burner 1, the minimum combustion amount, and the combustion range based on the minimum combustion amount. The flame distribution of 1 tends to have a large flame at the tip 31 and a small flame at the root 32. Therefore, in the first combustion chamber flame hole 5 and the second secondary flame hole 20 of the second combustion chamber 4, the opening of the root portion 32 is set to the flame from the opening of the tip portion 31 corresponding to the flame distribution of the burner 1. The size is reduced corresponding to the distribution.
[0026]
In the case of maximum combustion in the burner device configured as described above, a primary flame 19 is formed on the primary flame hole 2 and a secondary flame 12 is formed on the second secondary flame hole 20 to form a complete two-stage. It becomes a separate flame.
[0027]
Further, at the time of the minimum combustion, the primary flame 19 is formed on the primary flame hole 2 and the secondary flame 12a is formed on the first combustion chamber flame hole 5, and here also becomes a complete two-stage separation flame. For this reason, a complete two-stage separated flame can be realized over the entire combustion amount, and stable low NOx combustion can be realized at all times.
[0028]
(Example 2)
On the other hand, the primary flame 19 is likely to lift under conditions where the primary air is insufficient or the oxygen concentration in the atmosphere is reduced. When the air inlet 31 with filter provided behind the outer box 25 becomes clogged with dust for a long period of time, the amount of air taken in by the fan 10 decreases, and the combustion air that can be sucked into the burner 1 from the burner inlet 30 Air volume is also reduced.
[0029]
When the primary air shortage occurs in this way, the gas mixture that has reached the second secondary flame hole 20 due to the lack of oxygen for combustion seeks the combustion air from the second secondary flame hole 20 to the surroundings. It tries to complete combustion quickly. A so-called lift phenomenon occurs.
[0030]
Further, in a use example in which oxygen is not supplied by diffusion with fresh air outside the room due to long-term combustion in a sealed room, the oxygen concentration in the air is lowered. In such a case as well, the combustion becomes lifted like the above-mentioned air shortage, and the generation of harmful gases such as CO gas and NOx increases.
[0031]
In such a case, since the auxiliary air hole 27 of the first combustion chamber 3 communicates with the outside air, the combustion air can be inflow even when the combustion of the primary flame 19 is destabilized. The auxiliary air hole 27 has a function of supplying a little primary air to the secondary flame 12 at a normal time and a function of supplying a little secondary air to the secondary flame 12a.
[0032]
In the case where the oxygen supply amount is insufficient as described above, the degree of deterioration of the combustion performance can be alleviated until it acts as an emergency air supply hole and reaches a certain low oxygen concentration. In other words, it works to the extent that it does not have to be expected at all in normal times, but it can be done with an opening area that can be expected to work at low oxygen concentrations, and it has more positive effects at normal times. May be allowed.
[0033]
【The invention's effect】
As described above, according to the burner device of the present invention, the following effects can be obtained.
[0034]
In claim 1, the Bunsen burner is covered with a combustion chamber having a flame hole, and further covered with a first combustion chamber having a primary flame hole in the burner body, so that the fuel in the entire combustion region extending from the minimum combustion time to the maximum combustion time. The mixing ratio of the gas and the primary air for combustion can be made uniform, and two-stage combustion can be achieved, and low NOx can be expected.
[0035]
In claim 2, by providing an auxiliary air hole in the combustion chamber wall communicating with the outside air, the inflow of auxiliary air for combustion can be achieved when the primary air is insufficient and the oxygen concentration in the atmosphere is reduced, and the flame is stabilized. Can be
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a burner device in an embodiment of the present invention. FIG. 2A is an external view of the burner device. FIG. 1B is a top view of the second combustion chamber. Top view (d) Cross-sectional view of the burner device [Fig. 3] Configuration diagram of a hot air heater using the burner device of the embodiment of the present invention [Fig. 4] Vertical cross-sectional view of a conventional device [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Burner 2 Primary flame hole 3 1st combustion chamber 4 2nd combustion chamber 5 1st secondary flame hole 12 Secondary flame 19 Primary flame 20 2nd secondary flame hole 27 Auxiliary air hole

Claims (2)

A Bunsen burner having a primary flame hole on the upper surface, a box-like first combustion chamber that surrounds the primary flame hole in a substantially airtight manner, and a second portion sharing the bottom of the first combustion chamber on the outside. A combustion chamber, a second secondary flame hole corresponding to the flame shape at the time of maximum combustion of the Bunsen burner at the top of the second combustion chamber, and the Bunsen at the top of the first combustion chamber. A burner device having a first secondary flame hole corresponding to a flame shape at the time of minimum combustion of the burner. The burner apparatus of Claim 1 provided with the auxiliary air hole which penetrates the bottom part of a 1st combustion chamber.

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