JPH06300227A - Burner - Google Patents

Abstract

(57) [Summary] [Object] In a premixing burner that forms an opposing flame, a counterflow flame is formed in which the flame tips do not face each other and the flame tips face each other. [Structure] Slit flame holes 22 provided in mutually facing primary combustion chamber walls 19 are made to face each other. The fuel supply passage 8 is provided outside the primary combustion chamber wall 19, and the outlet of the fuel supply passage 8 serves as the slit 22 of the flame hole. The slit flame holes 22 form a flame hole array in the longitudinal direction. Adjacent slit flame holes 22 are separated from each other to form a combustion gas passage 23 between them. Several rows of the slit flame holes are arranged in the direction of the combustion chamber outlet 21. Then, a split plate 24 is provided in a direction perpendicular to the long side of the slit flame hole 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner having a wide range of combustion heat quantity variation (hereinafter referred to as TDR) in an industrial / commercial or household burner.

[0002]

2. Description of the Related Art Conventionally, as industrial, commercial or household burners, burners utilizing premixed combustion in which fuel and air are premixed and burned have been used. In such a burner, premixed gas is ignited on the flame hole to form a premixed flame. And when the premixed air is partially premixed,
Secondary air was supplied from around the premixed flame to diffuse and burn unburned gas. Further, a premixed counterflow burner has been proposed in which the premixed flames are opposed to each other to form a counterflow flame so that the combustion heat quantity can be varied in a wide range.

[0003]

In the premixed counterflow burner, when the combustion heat amount is increased, the speed of the premixed gas ejected from the flame hole is increased. However, even in such a case, the counterflow flame is formed. It had the advantage of stable combustion. However, when the velocity of the premixed gas increases, the opposing flame tips pass each other, so that the flame tips may form unstable flames without forming opposing flames. Therefore, TDR could not be sufficiently secured.
Further, in order to prevent the flame tip from passing each other, the flame hole is made into a slit shape, and a partition plate that divides the slit in the longitudinal direction is inserted to flatten the flame tip. However, if the distance between the slit flame holes facing each other is increased, the flame tip portion is not flattened, so that it is not possible to sufficiently prevent the flames from passing each other.

In consideration of the above-mentioned conventional problems, the present invention forms a facing flame in which the flame tips face each other in a premixing burner which forms a facing flame and the flame tips do not pass each other, and a wide variable range of combustion heat amount is obtained. The purpose is to provide a burner.

[0005]

In order to achieve the above object, in the first aspect of the invention, a large number of slit flame holes provided in mutually facing primary combustion chamber walls are opposed to each other. A fuel supply passage is provided outside the primary combustion chamber wall, and the outlet of the fuel supply passage serves as a slit flame hole. The slit flame holes form a flame hole array in the longitudinal direction. Adjacent slit flame holes are separated, and the space between them serves as a combustion gas passage. Several rows of this slit flame hole are arranged in the direction of the exit of the combustion chamber. Then, a dividing plate is provided in the vertical direction on the long side of the slit flame hole.

In the second aspect of the invention, a large number of slit flame holes provided in the primary combustion chamber walls facing each other are made to face each other. A fuel supply passage is provided outside the primary combustion chamber wall, and the outlet of the fuel supply passage serves as the slit flame hole. The slit flame holes form a flame hole array in the longitudinal direction. Adjacent slit flame holes are separated, and the space between them serves as a combustion gas passage. Several rows of this slit flame hole are arranged in the direction of the exit of the combustion chamber. Then, a narrow portion is provided on the long side of the slit flame hole.

In the third aspect of the invention, a large number of slit flame holes provided in the primary combustion chamber walls facing each other are made to face each other. A fuel supply passage is provided outside the primary combustion chamber wall, and the outlet of the fuel supply passage serves as the slit flame hole. The slit flame holes form a flame hole array in the longitudinal direction. Adjacent slit flame holes are separated, and the space between them serves as a combustion gas passage. Several rows of this slit flame hole are arranged in the direction of the exit of the combustion chamber. A partition plate is provided in the longitudinal direction of the slit flame hole, and a dividing plate or a narrow portion is provided in the long side in the direction perpendicular to the long side.

In the fourth aspect of the invention, a large number of slit flame holes provided in the primary combustion chamber walls facing each other are made to face each other. A fuel supply passage is provided outside the primary combustion chamber wall, and the outlet of the fuel supply passage serves as the slit flame hole. The slit flame holes form a flame hole array in the longitudinal direction. Adjacent slit flame holes are separated, and the space between them serves as a combustion gas passage. Several rows of this slit flame hole are arranged in the direction of the exit of the combustion chamber. The flame detecting element is arranged at a position facing a dividing plate or a narrow portion dividing the slit flame hole.

[0009]

In the burner according to the first aspect of the present invention, the slit-shaped flame hole is formed, and the central portion of the slit flame hole is divided into small flame holes. Therefore, the width of the tip of the flame is widened, and the flame passes the opposing flame. Instead, they form a counterflow flame with the flame tips facing each other. When the amount of heat supplied is small, a small cone-shaped flame is formed on the small flame hole to prevent flashback.

According to the second aspect of the invention, since the narrow portion is provided on the long side of the slit flame hole, the premixed gas flowing through the narrow portion is reduced. In the narrow portion, the length of the flame becomes shorter, and the width of the flame tip portion formed in the slit flame hole becomes wider. As a result, the opposing flow flame is formed without the flames passing each other. In this case, since the premixed gas flows even in the narrow portion of the slit flame hole, even if the amount of heat supplied is small, the flame is not cut off in the narrow portion, so that combustion detection by the flame detection element can be sufficiently performed.

In the third invention, since the slit flame hole is divided in the direction perpendicular to the longitudinal direction and the long side, the tip of the flame is spread in the longitudinal direction or in the direction perpendicular to the long side, and the flame tip becomes flat. The flame tips easily face each other.

In the fourth invention, the flame is formed so as to surround the flame detecting element. Therefore, a sufficient flame current can be secured. Further, since the flame detection element is uniformly heated by the flame, it has no deformation and has good durability.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view, partly in section, of an embodiment of the present invention. As components, 1 in the drawing is a burner body, 2
Is a primary combustion chamber, and 3 is a secondary combustion chamber. Reference numeral 4 is a combustion chamber composed of a primary combustion chamber 2 and a secondary combustion chamber 3. 5 is a flame hole, 6
Is a burner header, 7 is a secondary air hole, 8 is a fuel supply path, 9
Is a fuel branch pipe, 10 is a header flange, 11 is a burner cover, 12 is a burner cooling passage, 13 is a secondary air passage, 14
Is a bottom plate, 15 is an opposing flame, 16 is a secondary flame, 17 is a premixed gas, 18 is secondary air, 19 is a primary combustion chamber wall, 20 is a secondary combustion chamber wall, and 21 is a combustion chamber outlet.

FIG. 2 is a sectional view of an embodiment of the present invention as seen from another direction. Reference numeral 22 denotes a slit-shaped flame hole 5, which is hereinafter referred to as a slit flame hole. Reference numeral 23 is a combustion gas passage formed between the adjacent slit flames 22. A dividing plate 24 is provided at the center of the slit flame hole 22. Reference numeral 25 is a fuel header, and 26 is a secondary air header.
In FIG. 2, when the horizontal direction is the longitudinal direction of the burner, the slit flame holes 22 are arranged in the longitudinal direction of the burner.

The burner header 6 is composed of a fuel branch pipe 9 and a large number of fuel supply passages 8 and header flanges 10 communicating with the fuel branch pipe 9. The outlet of the fuel supply passage 8 is a flame hole. It becomes 5. The combustion chamber 4 composed of the primary combustion chamber 2 and the secondary combustion chamber 3 has a plurality of header flanges 10.
Are arranged to form a primary combustion chamber wall 19, which are opposed to each other to form the primary combustion chamber 2, and a bottom plate 14 having a rectangular shape is provided on the bottom thereof. A large number of slit flame holes 22 are provided in the primary combustion chamber wall 19, and the slit flame holes 22 of the primary combustion chamber wall 19 facing each other are arranged coaxially with each other. The secondary combustion chamber 3 is composed of secondary combustion chamber walls 20 facing each other. The secondary combustion chamber wall 20 is provided with a large number of secondary air holes 7.

In the embodiment having the above structure, the fuel and the primary air are mixed to form the premixed gas 17, which is supplied to the fuel branch pipe 9 passing through the fuel header 25 and communicating therewith, and passing through the fuel supply passage 8. , From the slit flame hole 22 to the primary combustion chamber 2. On the other hand, the secondary air 18 passes through the secondary air header 26 and is supplied to the burner cooling passage 12 that communicates with the secondary air header 26, cools the primary combustion chamber wall 19 and the fuel supply passage 8, and the secondary air hole 7 increases in temperature. Is supplied to the secondary combustion chamber 3.
The burner cooling passage 12 forms a part of the secondary air passage 13. The secondary air passage 13 includes a burner header 6 and a burner cover 11.

When the premixed gas 17 ejected from the slit flame hole 22 into the primary combustion chamber 2 is ignited, when the premixed gas 17 is ejected at a high speed, the flame is separated from the slit flame hole 22 and the flames facing each other are generated. The opposing flames 15 are formed close to each other. Since the opposing flame 15 often burns away from the slit flame hole 22, a part of the premixed gas is discharged unburned from the vicinity of the slit flame hole 22 without passing through the flame zone. However, since a plurality of rows of slit flame holes 22 are separated and arranged toward the combustion chamber outlet 21, the unburned premixed gas has a high temperature which flows between the flame near the combustion chamber outlet 21 or between the adjacent slit flames 22. Complete combustion with combustion gas. When the excess air ratio of the premixed air is 1 or less, the secondary flame 16 is formed by the secondary air 18 supplied from the secondary air hole 7, and complete combustion is performed.

3 (a) and 3 (b) are characteristic flame shape diagrams of the first invention, and the opposing flame 15 near the outlet of the combustion chamber is shown.
The detailed drawing of is shown. As is clear from this figure, the tip of the flame 15 approaches. Reference numeral 27 is a combustion gas flowing through the combustion gas passage 23.

The feature of this embodiment is that the opposing flame is stably formed. For that purpose, the slit flame hole 22 is adopted and its arrangement is devised. The premixed gas 17 ejected from the slit flame hole 22 forms the opposing flame 15. When the jet speed of the premixed gas 17 is high, the flame tips collide. The combustion gas 27 flows toward the combustion chamber outlet 21 through the combustion gas passage 23 formed between the adjacent slit flame holes 22. At this time, the combustion gas passage 23 is connected to the combustion chamber outlet 2
A slight change in the combustion gas flowing toward 1 causes the flame tip to move toward or away from the adjacent flame. When the shape of the flame hole is circular, the flame becomes a cone shape and the flame tip portion often passes the opposing flame. However, when the slit flame hole 22 is formed as in the embodiment, the flame tip portions can face each other. .

The opposing flame 15 bends toward the combustion chamber outlet 21 (15a). In particular, the flame after the collision is the combustion chamber outlet 2
Turn to one direction. At this time, the bending of the opposing flame 15 is reduced by flowing the combustion gas 27 into the combustion gas passage 23. If the combustion gas passage 23 is not provided, the combustion gas 27
Flows between the opposite flame tips, the flame tips face the direction of the combustion chamber outlet 21 without colliding, and the stability of the flame deteriorates.

Further, in this embodiment, the slit flame hole 22 is located at the outlet of the fuel supply passage 8 provided outside the primary combustion chamber wall 19. Even if the periphery of the slit flame hole 22 is heated, the temperature of the fuel supply passage 8 does not rise due to cooling, and the premixture is not preheated. Therefore, there is no flashback due to preheating of the premixed gas.

FIG. 4 is a characteristic flame form diagram of the embodiment of the present invention. Since the slit flame hole 22 is provided with the dividing plate 24, when the premixed gas ejection speed is low, the flame tip has two peaks as shown in FIG. 4A. When the premixed gas ejection speed increases, the flame gradually expands, as shown in Fig. 4 (b).
4C, and as shown in FIG. 4C, the twin flames 29 facing each other in the vicinity of the stagnation portion 28 have a flow velocity of 0, so that stable combustion is achieved. FIG. 4B shows a flame form intermediate between those in FIGS. 4A and 4C. According to this structure, the flame tip is flattened, the flame becomes a flat tip having a wide width in the longitudinal direction, and the flame can easily face each other.

In the second invention, as shown in FIG. 5, the slit flame hole 22 is provided with a narrow portion 30 in place of the partition plate 24. The velocity of the premixed gas ejected from the narrow portion 30 becomes low, and the flame takes a concave shape having a short length in the narrow portion 30, but unlike the partition plate 24, the premixed gas is ejected also in the narrow portion 30. Even if the air-fuel mixture ejection speed is low, the flame is not divided by the slit flame holes as shown in FIG. 4 (a). Therefore, stable combustion can be achieved.

In the third invention, as shown in FIG. 6, a partition plate 31 is provided in the longitudinal direction of the slit flame hole 22 and a dividing plate 32 is provided in a direction perpendicular to the long side of the slit flame hole 22. With such a configuration, the flame becomes flat in both the longitudinal direction and the outlet direction, and the flames face each other very well.

FIG. 7 shows the burner as seen from the outlet direction of the combustion chamber. The flame detection positive element 33 and the flame detection negative element 34 are inserted from the combustion chamber outlet direction. By the dividing plate 24,
The flame tip shows a concave shape. Since the flame is located around the flame detection positive element 33 and the negative element 34, it is possible to secure a sufficient current value when detecting the flame current. When detecting the temperature, either the positive element 33 or the negative element 34 may be used. A narrow portion may be provided instead of the dividing plate 24. In this case, since the flame is not broken at the slit flame holes, it is possible to detect a large flame current or a high temperature.

[0026]

As is clear from the description of the above embodiment,
INDUSTRIAL APPLICABILITY The present invention provides a burner that burns stably even when the amount of heat of combustion is large and that produces quiet combustion noise. By arranging a plurality of slit flame hole rows toward the combustion chamber outlet, forming a combustion gas passage between adjacent flame holes, and further, forming each slit flame hole as an outlet between the fuel supplies installed outside the combustion chamber wall. ,
Even if the flame temperature does not rise and the amount of heat of combustion is large, an opposing flame is formed in the stagnation region. Therefore, stable combustion with low combustion noise can be performed, and TDR is large. Further, by providing the recessed portion at the center of the slit flame hole, the flame tip portion becomes two ridges or becomes flat, facilitating the opposing of the flame tip portion, and further enhancing flame stability. Further, by disposing the flame detecting element in the center of the combustion chamber corresponding to the facing concave portion, the flame current is sufficiently secured and the durability of the flame detecting element is improved.

[Brief description of drawings]

FIG. 1 is a perspective view in which a portion of a burner according to an embodiment of the present invention is partially sectioned.

FIG. 2 is a sectional view of the same embodiment.

FIG. 3 is an explanatory view of a slit flame port and flame of the burner.

FIG. 4 is a sectional view of the slit flame mouth of the burner.

FIG. 5 is a sectional view of another embodiment of the present invention.

FIG. 6 is a sectional view of another embodiment of the present invention.

FIG. 7 is a cross-sectional view of an essential part of another embodiment of the present invention.

[Explanation of symbols]

 1 Burner Main Body 2 Primary Combustion Chamber 8 Fuel Supply Channel 15 Opposed Flame 19 Primary Combustion Chamber Wall 22 Slit Flame Hole 24 Dividing Plate 30 Narrow Portion 33 Flame Detection Positive Element

Claims (9)

[Claims] 1. A plurality of slit flame holes are spaced apart from each other on each of opposing surfaces of primary combustion chamber walls that form a combustion chamber facing each other, and the slit flame hole rows are provided in the combustion chamber. A plurality of stages are provided in the outlet direction of the chamber, the space between the slit flame holes is used as a combustion gas passage, and fuel is supplied to each slit flame hole from the outside of the wall of the primary combustion chamber via a fuel supply passage. A burner provided with a dividing plate that divides the slit flame hole into right and left in a direction perpendicular to the long side of the hole. 2. The burner according to claim 1, wherein the dividing plate is positioned upstream of the flow surface of the premixed gas with respect to the opening surface of the slit flame hole. 3. A plurality of slit flame holes are spaced apart from each other on opposite surfaces of primary combustion chamber walls constituting the combustion chamber so as to face each other, and the slit flame hole rows are provided in a row. In the burner for supplying fuel to each slit flame hole from the outside of the primary combustion chamber wall through a fuel supply passage, the slit flame is provided in a plurality of stages in the outlet direction of the chamber, the space between the slit flame holes is used as a combustion gas passage. Burner with a narrowed part in the center of the long side of the hole. 4. The burner according to claim 3, wherein the narrowed portion is provided upstream of the opening surface of the slit flame hole in the flow of the premixed gas. 5. A plurality of slit flame holes are spaced apart from each other on opposite surfaces of primary combustion chamber walls that form a combustion chamber facing each other, and the slit flame hole rows are provided in a row. In the burner for supplying fuel to each of the flame holes from the outside of the primary combustion chamber wall through a fuel supply passage, the slit flame holes are provided in a plurality of stages in the outlet direction of the chamber, and the slit flame holes are used as combustion gas passages. The burner according to claim 1 or 3, wherein a partition plate that divides the upper and lower parts is installed in the longitudinal direction. 6. The burner according to claim 1, wherein a flame detection element is located at a position where the division plates face each other. 7. The burner according to claim 3, wherein a flame detection element is located at a position where the narrow portion faces. 8. The flame detecting element comprises a flame detecting positive element and a flame detecting negative element, and the flame hole facing the flame detecting positive element is different from the flame hole facing the flame detecting negative element. Burner described. 9. A plurality of slit-shaped flame holes are spaced apart from each other on opposing surfaces of primary combustion chamber walls that form a combustion chamber facing each other, and the flame hole rows are provided in the combustion chamber. A plurality of stages are provided in the outlet direction of each of the slit flame holes as a combustion gas passage, and fuel is supplied to the respective slit flame holes from the outside of the primary combustion chamber wall through a fuel supply passage to move the slit flame holes up and down. A burner in which a partition plate to be divided into two is installed in the longitudinal direction, and a flame detection element is located at a position facing the partition plate.