JPH07180814A - Double-stage combustion burner device - Google Patents

Abstract

PURPOSE:To realize a low NOx combustion even if a combustion amount is changed. CONSTITUTION:A space higher than a primary flame hole 2 of a Bunsen burner 1 is applied as a combustion chamber 4, an upper part of the combustion chamber 4 is opened to act as a high combustion secondary flame hole 20. In addition, a projecting flame hole 5 dividing the combustion chamber 4 into an upper segment and a lower segment is formed between the primary flame hole 2 and a secondary flame hole 20. With such an arrangement as above, the primary flame 19 and the secondary flame 12 are separated from each other and then a double-stage combustion which is always stable can be formed not in response to a combustion amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for reducing NOx suitable for household combustion equipment.

[0002]

2. Description of the Related Art Conventionally, a device of this type is disclosed in FIG.
As in Japanese Patent Laid-Open No. 2-39329, the Bunsen burner 11 has a primary flame hole 12 that partially opens on the upper surface and is covered with a primary combustion chamber wall 13 having a secondary flame hole 14. With this configuration, the flame at the time of maximum combustion is the primary flame hole 12
A primary flame 15 is formed on the upper side, and a secondary flame 16 is formed on the secondary flame hole 14. Further, at the time of minimum combustion, the primary flame 1 on the primary flame hole 12
The secondary flame 16 could not be formed in the secondary flame hole 14 immediately outside of No. 5, and the secondary flame 16a was formed immediately outside of the primary flame 15 in the wall of the primary combustion chamber.

[0003]

However, in this kind of two-stage combustion, the primary flame hole 12 and the secondary flame hole 1 are usually used.
The load of 4 is designed with a value suitable for the maximum combustion amount. For this reason, at maximum combustion, a perfect 2 due to flame holding in each flame hole 12,14.
Stage combustion can be formed. On the other hand, if the combustion amount is reduced, the secondary flame hole 1
Since the load on 4 is too low, the secondary flame 16 is less likely to be formed on the secondary flame hole 14 and the two-stage combustion does not occur, and the secondary flame 16a is formed on the primary flame hole 12 outside the primary flame 15. It becomes a normal premixed flame that can be integrated, and the NOx concentration in the combustion exhaust gas increases. That is, when the amount of combustion is reduced, there is a problem that two-stage combustion is not performed and low NOx combustion cannot be realized.

[0004]

In order to solve the above-mentioned problems, according to the two-stage burner device of the present invention, (1) a Bunsen burner having a primary flame hole is provided and the Bunsen burner is housed in the primary burner. The combustion chamber in the space above the flame hole, the secondary flame hole that opens the upper surface of the combustion chamber, the combustion chamber is divided into upper and lower parts in the middle of the primary flame hole and the secondary flame hole, and the primary flame on the primary flame rises. It is provided with a convex flame hole formed so that the cross-sectional area of the passing combustion chamber is narrowed.

(2) The load on the convex flame holes is smaller than the load on the primary flame holes and is equal to or larger than the load on the secondary flame holes.

[0006]

With the above construction, each means of the present invention operates as follows.

In the first means, the secondary flame is formed on the secondary flame hole when the amount of combustion is large, resulting in two-stage combustion. Also,
When the amount of combustion is small, the secondary flame is formed on the convex flame hole, and even if the position of the secondary flame changes, two-stage combustion occurs. Further, by forming the convex flame holes that protrude the inner wall of the combustion chamber, stable two-stage combustion can always be realized and good low NOx can be realized.
It becomes possible to burn.

In the second means, when the amount of combustion is small, the convex flame hole load is made smaller than the primary flame hole load, whereby the ejection speed of the gas ejected from the primary flame hole is suppressed and the primary flame is suppressed. A primary flame is formed on the holes, and a secondary flame is formed in two stages on the convex flame holes to enhance the flame holding effect. Also, when the combustion amount is large, the secondary flame hole load is made equal to or smaller than the convex flame hole load, so that the primary flame is formed on the primary flame hole and the secondary flame is formed on the secondary flame hole. Again, a two-stage combustion is formed. By setting the flame hole load, stable two-stage combustion is always formed according to the amount of combustion, and good low NOx combustion is possible.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. 1 and 2 are cross-sectional views of a warm air warmer used in the present invention, in which 1 is a burner body and 2 primary flame holes. The primary flame holes 2 are on the upper surface or the side surface of the burner body 1, and the primary flame hole shape may be a slit having a long shape or a round hole. Further, the primary flame hole 2 may be covered with a wire mesh. 3 is the wall of the combustion chamber, 5
Is a convex flame hole, and the combustion chamber 4 that houses the burner body 1 includes a combustion guide A6, a combustion guide B7, and a combustion guide C8.
It is covered by. When burning, the blade is driven by the motor 1
0 rotates, and the hot air heated by the burner body 1 and the like is sucked by the blades 10 and flows along the blade guides 17. The air required for combustion passes between the combustion guide B7 and the combustion guide C8 and becomes combustion air. Also, the combustion guide C8
The air passing between the combustion guide A6 and the combustion guide A6 is mixed with hot air and becomes warm air, which flows along the blade guide 17 by the suction force of the blade 10. The combustion guide D18 is a guide for a passage of hot air heated by the burner 1. The combustion chamber unit 24 is covered with an outer casing 25, and the warm air flowing along the vane guides 17 has a warm air outlet 26 provided in the outer casing 25.
More blown out. Next, the structure of the combustion chamber 4 will be described in more detail with reference to FIG. The combustion chamber 4 is provided with a convex flame hole 5, which is formed by bending or pressing at the time of processing the combustion chamber wall 3 and is integrally processed. Thermal deformation, thermal strain, and the like during heating and cooling of the combustion chamber wall 3 come into contact with the outside air at the recess 5a, so that they can be prevented by being cooled to the outside air. The convex flame holes 5 can be configured by attaching another component. Also in the attachment of another component, by integrally processing the convex flame holes 5 which is the feature of the present invention, the cooling space in the concave portion 5a communicating with the outside air is secured.

Next, the convex flame hole load of the convex flame hole 5 (the ratio of the combustion amount in the convex flame hole 5 to the flame hole area 22) is smaller than the primary flame hole load of the primary flame hole 2, Secondary flame hole load of the secondary flame hole 20 (combustion amount flame hole area 23 burned in the secondary flame hole 20)
The ratio) is equal to or larger than that of the convex flame hole load 22. The height position L1 of the convex flame hole 5 provided in the combustion chamber 4 is set according to the combustion range of the burner 1 according to the maximum combustion amount and the minimum combustion amount.

In the burner apparatus configured as described above, when the combustion amount is large, the primary flame 19 is formed on the primary flame hole 2 and the secondary flame 12 is formed on the secondary flame hole 20 to form a complete separation flame. Become. When the combustion amount is small, the primary flame 19 is formed on the primary flame hole 2 and the secondary flame 12a is formed on the convex flame hole 5 as shown in FIG. . Therefore, a complete separation flame can be realized over the entire combustion amount, and stable low NOx combustion can always be realized.

When the combustion range of the combustion amount is not so large and the secondary flames 12 and 12a can be divided into two combustion amounts, large and small, to hold the flame, the convex flame hole 5 is provided at one place as in this example. Good. However, in the single convex flame hole 5, the secondary flame becomes integral with the primary flame when the amount of combustion is small. Therefore, if the range of the combustion amount is further subdivided and a plurality of convex flame holes 5 are provided according to the number of the divided combustion amount ranges, the two-stage combustion in the entire combustion range can be secured. In addition, when the combustion range actually used in the entire combustion range can be limited, that is, when the combustion control is not performed only in a certain combustion range, the convex flame holes 5 corresponding to the actually used combustion range
It is also possible to provide only.

[0013]

As described above, according to the burner device of the present invention, the following effects can be obtained.

(1) According to the first aspect of the present invention, the burner body is covered with the box having the secondary flame holes, and the convex flame holes are formed in the wall of the combustion chamber, so that stable two-stage combustion can be always realized, and low burn-up can be achieved. NO
x burning becomes possible.

(2) In claim 2, when the combustion amount is small,
Since the convex flame holes on the wall of the combustion chamber enhance the flame holding property of the primary flame on the primary flame holes, CO in the exhaust gas can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a burner device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a combustion state when the combustion amount is large in the same device.

FIG. 3 is a sectional view showing a combustion state in the same device when the combustion amount is small.

FIG. 4 is a sectional view of a conventional burner device.

[Explanation of symbols]

 1 Burner body 2 Primary flame hole 3 Combustion chamber wall 4 Combustion chamber 5 Convex flame hole 12, 12a Secondary flame 19 Primary flame 20 Secondary flame hole

Claims (2)

[Claims] 1. A Bunsen burner having a primary flame hole, a combustion chamber accommodating the Bunsen burner and having a space above the primary flame hole, and a secondary flame hole opened at the upper portion of the combustion chamber. A two-stage combustion burner device comprising: a convex flame hole having a convex portion formed between the primary flame hole and the secondary flame hole toward the inside of the combustion chamber so as to narrow the combustion chamber. 2. The two-stage combustion burner device according to claim 1, wherein the load of the convex flame holes is smaller than the load of the primary flame holes and equal to or larger than the load of the secondary flame holes.