JP2001201018A - Burner of heating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a burner of a heating furnace capable of preventing a normal combustion state from being damaged by deformation of a refractory material. SOLUTION: There is provided a burner of a heating furnace in which a burner tile 12 is installed at a front side of a burner, and both fuel and oxidant agent are injected to perform combustion. An outer peripheral surface of the burner tile 12 is provided with cooling oxidant agent injection holes 14a where a part of the oxidant agent is injected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a structure of a burner for a heating furnace used at a high temperature.

[0002]

Generally, burners used in heating furnaces such as glass melting furnaces and incineration ash melting furnaces whose operating temperatures exceed 1000 ° C. are required to reduce NOx. Some fuels and oxidizers (air, oxygen, oxygen-enriched air) are injected into a furnace at a high speed of, for example, 50 m / s or more to perform combustion.

FIG. 12 is a side view showing a conventional low NOx burner for a heating furnace, and FIG. 13 is a front view thereof. 12 and 13, a low NOx burner 1 has a burner tile 3 formed of a refractory material attached to a front portion of a burner main body 2, and a fuel injection hole 3A at a central portion of a front surface of the burner tile 3. The oxidizing agent injection holes 3B are formed at the four corners.

The low NOx burner 1 is mounted on the furnace wall of a heating furnace, and performs combustion by directly injecting fuel and oxidant from the fuel injection holes 3A and oxidant injection holes 3B into the furnace, respectively. At this time, the reduction of NOx is realized by the self-exhaust gas recirculation effect of performing combustion by involving the combustion gas having a low oxygen concentration in the furnace by the ejection energy of the fuel and the oxidant.

In such a low NOx burner, primary air for combustion is injected from an oxidizing agent injection hole provided at an outer peripheral portion of a fuel injection hole, and oxidizing agent injection holes formed at four corners of a burner tile. There is also a so-called two-stage combustion burner which performs two-stage combustion by injecting secondary air for combustion.

[0006] In the case of a low NOx burner for a heating furnace used at such a high temperature, the burner tile 3 facing the inside of the furnace is used.
Is heated at a high temperature by the flame and radiant heat in the furnace.

For this reason, in the conventional low NOx burner, the peripheral portion of the fuel injection hole 3A or the oxidant injection hole 3B is melted and damaged, and the opening area becomes large as shown in FIG. In some cases, as shown in FIG. 14B, the melted portion 3a at the upper portion of the injection port may hang down.

In this case, the shape of the fuel injection holes 3A and the oxidizing agent injection holes 3B change the shape of the flame and the direction of injection by changing the shape of the injection holes, so that the temperature distribution in the furnace and the NOx emission concentration deteriorate. Problems arise.

Further, as shown in FIG. 14 (a), when the opening area of the fuel injection hole 3A or the oxidant injection hole 3B becomes large, incomplete combustion due to excessive fuel supply occurs, Problems such as a decrease in combustion efficiency and a decrease in furnace temperature due to excessive supply occur.

Further, as shown in FIG. 14 (b), when the upper part of the injection hole of the fuel injection hole 3A or the oxidant injection hole 3B melts and hangs down, the opening area of the injection hole becomes small, and the fuel injection hole becomes small. Problems such as a decrease in the furnace temperature due to the shortage and the occurrence of incomplete combustion due to the lack of oxygen occur.

Further, in a low NOx burner having a structure as shown in FIGS. 12 and 13, as shown in FIG.
A combustion gas recirculation region f in the furnace is formed around the injection holes of the fuel injection holes 3A and the oxidant injection holes 3B. In the recirculation region f, the combustion gas in the furnace is injected from the injection holes. The floating material in the furnace adheres to the surface of the burner tile 3 by flowing along the surface of the burner tile 3 by being attracted by the fuel and the oxidizing agent, and the floating material w attached is melted by heating. As a result, the same phenomenon as the state shown in FIG. 14B occurs.

FIG. 16 shows another type of conventional burner for a heating furnace. In the burner for a heating furnace shown in FIG. 16, a fuel injection pipe 5 provided with a flame holding plate 5 </ b> A at an outer peripheral end thereof is inserted into a flame hole 4 </ b> A formed at the center of the burner tile 4. At the same time as injecting fuel, the oxidant supplied from the oxidant supply port 6 is supplied through the injection holes 5Aa formed in the flame holding plate 5A and the gap between the flame holding plate 5A and the flame holes 4A of the burner tile 4. And the flame is blown out from the flame hole 4A.

For this reason, the burner tile 4 becomes high temperature,
Melting occurs around the opening of the flame hole 4A of the burner tile 4, or the floating matter in the heating furnace attached to the surface of the burner tile 4 is melted, so that the shape of the opening of the flame hole 4A is deformed. May change the shape of the flame,
In addition, problems such as a change in the supply ratio between the fuel and the oxidant occur.

The present invention has been made in order to solve the above-mentioned problems of the conventional burner for a heating furnace used at a high temperature. That is, an object of the present invention is to provide a burner for a heating furnace which can prevent a steady combustion state from being impaired by deformation due to heating of a burner tile.

[0015]

In order to achieve the above object, the burner for a heating furnace according to the first invention has a refractory at the front of the burner and injects fuel and oxidant to burn the fuel. The burner for a heating furnace to be performed is characterized in that a cooling oxidant supply unit for blowing out a part of the oxidant is provided on the outer peripheral surface side of the refractory.

The heating furnace burner according to the first invention is
It is attached to the furnace wall of the heating furnace and performs combustion by injecting fuel and oxidant into the furnace.

The heating furnace burner is communicated with the inside of the furnace between the inner wall surface of the mounting opening of the furnace wall and the portion of the heating furnace burner where the refractory cooling oxidant supply section is formed. Is secured to the furnace wall of the heating furnace in a state where the required gap is secured, so that during combustion, a part of the oxidant supplied to the furnace is cooled by the refractory Is blown out to the outer peripheral surface side.

The cooling oxidant blown out of the cooling oxidant supply unit flows along the outer peripheral surface of the refractory from the gap between the inner wall surface of the furnace wall and the inside of the furnace. When it flows in a layered manner and reaches the front side of the refractory, a negative pressure is created around the opening by the velocity energy of the fuel and oxidant injected from the opening on the front side of the refractory. The flow direction is changed and the refractory is drawn toward the opening along the front surface.

Therefore, according to the first aspect of the present invention, when the burner for the heating furnace is burned, a part of the oxidizing agent blows out to the outer peripheral surface of the refractory for cooling, and flows along the surface of the refractory. Since the refractory flows in a layered manner, the surface of the refractory is cooled, thereby preventing the surface temperature of the refractory from rising due to a flame or heating by radiant heat from inside the furnace. In addition to preventing the opening from being deformed due to the melting of the refractory, the layered oxidizing agent flowing along the surface of the refractory prevents the suspended matter in the furnace from adhering to the refractory itself, thereby increasing the heating. The steady combustion state of the furnace burner can be maintained.

According to a second aspect of the present invention, in order to achieve the above object, in addition to the configuration of the first aspect, the cooling oxidant supply unit opens on the outer peripheral surface of the refractory. And a cooling oxidant injection hole communicating with an oxidant supply passage formed in the refractory.

According to the burner for a heating furnace according to the second aspect of the present invention, the cooling oxidant injection hole is opened on the outer peripheral surface of the refractory and communicates with the oxidant supply passage in the refractory. At the time of combustion, a part of the oxidant flowing through the oxidant supply passage is blown out from the outer peripheral surface side of the refractory, and the blown cooling oxidant flows along the surface of the refractory, thereby forming the refractory. The rise in surface temperature is suppressed, and the adhesion of suspended matter in the furnace to the surface of the refractory is prevented.

According to a third aspect of the present invention, there is provided a burner for a heating furnace according to the second aspect of the present invention, in addition to the structure of the second aspect, wherein the refractory is provided with a cooling oxidant injection hole. It is characterized in that the cross section of the rear portion is shaped to be larger than the cross section of the portion where the cooling oxidant injection hole is provided.

According to the burner for a heating furnace according to the third aspect of the present invention, when the burner for the heating furnace is inserted into and supported in the mounting hole of the furnace wall of the heating furnace, the oxidizing agent injection hole for cooling the refractory is provided. The size of the cross section of the portion behind the portion that is provided is larger than the size of the cross section of the portion where the cooling oxidant injection hole is provided, so that the heating furnace burner is Simply by inserting the cooling oxidizer injection hole into the mounting opening, the cooling oxidizer injection hole can be supported in a state where a gap is secured between the opening of the cooling oxidant injection hole and the inner wall surface of the furnace wall mounting opening. The front side of the burner main body that supports the refractory is covered by a portion behind the oxidizing agent injection hole for cooling the refractory, and the burner is covered by the burner. The front of the body is exposed in the furnace It becomes possible to prevent from being heated.

According to a fourth aspect of the present invention, there is provided a burner for a heating furnace according to the first aspect of the present invention, wherein the cooling oxidant supply unit is provided on a burner body supporting the refractory. The cooling oxidant supply opening is provided to blow the cooling oxidant forward along the outer peripheral surface of the refractory.

According to the burner for a heating furnace according to the fourth aspect of the present invention, at the time of combustion, the oxidizing agent supplied to the furnace from the cooling oxidizing agent supply section provided in the burner main body supporting the refractory. A part is blown forward along the outer peripheral surface of the refractory, thereby suppressing the temperature rise on the surface of the refractory and preventing the suspended matter in the furnace from adhering to the surface of the refractory.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a side view showing a first example in which the present invention is applied to a low NOx burner, FIG. 2 is a front view thereof, and FIG. 3 is a sectional view taken along line III-III of FIG. is there.

1 to 3, a low NOx burner 10 is provided with a burner tile 12 formed of a refractory material at the front of a burner body 11.

A fuel injection hole 13 communicating with a fuel supply passage in the burner main body 11 is opened at a central portion on a front surface of the burner tile 12, and further, at four corners, a fuel injection hole 13 in the burner main body 11 is provided. An oxidizing agent injection hole 14 communicated with the oxidizing agent supply passage is opened.

Of the oxidizing agent injection holes 14, a pair of cooling oxidizing agent injection holes 14 a opened on the upper surface and side surfaces of the burner tile 12 are provided on the oxidizing agent injection holes located above the fuel injection holes 13. And the fuel injection hole 1
The pair of oxidizing agent injection holes 14a opened on the lower surface and the side surface of the burner tile 12 communicates with the oxidizing agent injection holes located below the third oxidizing agent injection holes.

As shown in FIG. 4, the low NOx burner 10 has a required space between the outer peripheral surface of the burner tile 12 and the inner wall surface of the mounting port H1 in the mounting port H1 of the furnace wall H of the high temperature furnace. The fuel cell and the oxidant are directly injected into the furnace from the fuel injection holes 13 and the respective oxidant injection holes 14 to perform combustion.

The self-exhaust gas recirculation effect of entraining and combusting the low-oxygen-concentration combustion gas in the furnace by the injection energy of the fuel and the oxidizing agent at the time of this combustion makes the conventional low-NOx burner of FIGS. Similarly, reduction of NOx is realized.

Further, the low NOx burner 10
When the oxidizing agent is injected from the oxidizing agent injection hole 14 for combustion, the cooling oxidizing agent injection holes 14a that are respectively opened on the upper surface, the lower surface, and both side surfaces of the burner tile 12 are respectively oxidizing agent injection holes 14 By communicating with
A part of the oxidizing agent flowing through each oxidizing agent injection hole 14 is blown outward on the upper and lower surfaces and both side surfaces of the burner tile 12.

The oxidizing agent (hereinafter referred to as cooling oxidizing agent) blown out from each cooling oxidizing agent injection hole 14a is supplied to the burner tile 12 from the gap s between the furnace wall H and the inner wall surface of the mounting opening H1. It flows along the outer peripheral surface in a layered manner in the inside of the furnace.

When the cooling oxidant reaches the front side of the burner tile 12, the velocity energy of the oxidant injected from the oxidant injection hole 14 opened on the front side of the burner tile 12 causes the oxidant to cool. Since the pressure around the opening of the injection hole 14 is negative, the cooling oxidant flows in the direction of the opening of the oxidant injection hole 14 along the front surface of the burner tile 12 by changing the flowing direction. And merges with the oxidizing agent injected from the oxidizing agent injection hole 14.

Thus, the low NOx burner 10
At the time of combustion, a part of the oxidizing agent is blown out to the outer peripheral surface of the burner tile 12 for cooling, and flows in a layer along the surface of the burner tile 12, thereby cooling the surface of the burner tile 12 and causing a flame. In addition, the surface temperature of the burner tile 12 is suppressed from rising due to heating by radiant heat from the furnace.

As a result, the low NOx burner 10 prevents the fuel injection holes 13 and the oxidizing agent injection holes 14 from being deformed due to erosion and blocking the adhered suspended matter from melting, thereby maintaining a steady combustion state.

Furthermore, the low NOx burner 10 is provided with a layered cooling oxidant flowing along the surface of the burner tile 12 during combustion, so that the floating NO.
2 by preventing the fuel injection holes 13 and the oxidizing agent injection holes 14 from being clogged due to melting of the suspended matter, thereby maintaining a steady combustion state.

FIG. 5 is a side view showing a second example in which the present invention is applied to a low NOx burner, and FIG. 6 is a front view thereof.

5 and 6, a low NOx burner 20 has a burner tile 22 formed of a refractory material attached to a front portion of a burner main body 21. A burner tile 22 is provided at the center of the front surface of the burner tile 22. A fuel injection hole 23 communicated with a fuel supply passage in the main body 21 is opened, and an oxidant injection hole 24 communicated with an oxidant supply passage in the burner main body 21 is opened at each of the four corners. I have.

The burner body 21 of the low NOx burner 20
Is set to be larger in the up-down direction and the left-right direction than the size of the cross-sectional shape of the burner tile 22. And is exposed to the front side.

The outer peripheral portion of the front surface of the burner body 21 exposed on the front side is provided with a cooling oxidizer communicating with an oxidizing agent supply passage (not shown) in the burner body 21 over the entire circumference of the burner tile 22. An agent supply opening 25 is formed, and the cooling oxidant is blown out from the cooling oxidant supply opening 25 along the surface of the burner tile 22 in the forward direction.

This low NOx burner 20 is also the first NOx burner described above.
Similarly to the low NOx burner 10 of the example of the above, in the mounting opening of the furnace wall of the high temperature furnace, it is mounted in a state where a required gap is formed between the outer peripheral surface of the burner tile 22 and the inner wall surface of the mounting opening, The fuel and the oxidant are directly injected into the furnace from the fuel injection holes 23 and the respective oxidant injection holes 24 to perform combustion. At this time, the low oxygen in the furnace is generated by the ejection energy of the fuel and the oxidant during the combustion. The reduction of NOx is realized by the self-exhaust gas recirculation effect of performing combustion by involving the concentrated combustion gas.

The low NOx burner 20 blows the cooling oxidant forward through the cooling oxidant supply opening 25 during combustion, and the blown cooling oxidant is attached to the furnace wall. After flowing in a layered manner inside the furnace along the outer peripheral surface of the burner tile 22 through the gap between the inner wall surface of the mouth and the outer surface of the burner tile 22, the oxidant is injected from the oxidizing agent injection hole 24 opened in the front surface of the burner tile 22. The velocity energy of the oxidizing agent is attracted in the direction of the opening of the oxidizing agent injection hole 24 in which the peripheral portion has a negative pressure to change the flow, and the burner tile 22
Flows in the direction of the opening of the oxidizing agent injection hole 24 along the front surface of the oxidizing agent injection hole 24 and joins the oxidizing agent injected from the oxidizing agent injection hole 24.

As described above, the low NOx burner 20
At the time of combustion, the surface of the burner tile 22 is cooled by the cooling oxidant blown out from the cooling oxidant supply opening 25, so that the burner tile 22 is not heated by a flame or radiant heat from inside the furnace. To suppress the rise in surface temperature.

As a result, the low NOx burner 20 prevents the fuel injection holes 23 and the oxidant injection holes 24 from being deformed due to erosion and blocking the adhered suspended matter from melting, thereby maintaining a steady combustion state.

Furthermore, the low NOx burner 20 uses a cooling oxidant blown out from the cooling oxidant supply opening 25 during combustion to reduce the adhesion of suspended matter in the furnace to the burner tile 22 itself. By preventing the fuel injection holes 23 and the oxidant injection holes 24 from being blocked by the melting of the suspended matter, a steady combustion state is maintained.

FIG. 7 is a side view showing a third example in which the present invention is applied to a low NOx burner, and FIG. 8 is a front view thereof.

7 and 8, a low NOx burner 30 has a burner tile 32 formed of a refractory material attached to a front portion of a burner main body 31, and a burner tile 32 is provided at the center of the front surface of the burner tile 32. A fuel injection hole 33 communicated with a fuel supply passage in the main body 31 is opened, and an oxidant injection hole 34 communicated with an oxidant supply passage in the burner main body 31 is opened at each of the four corners. I have.

Of the oxidizing agent injection holes 34, the oxidizing agent injection holes located above the fuel injection holes 33 include:
A pair of cooling oxidant injection holes 34 a opened on the upper surface and the side surface of the burner tile 32 are communicated with each other, and the lower surface of the burner tile 32 is connected to the oxidant injection hole located below the fuel injection holes 33. And a pair of cooling oxidant injection holes 34a opened on the side surfaces thereof.

The above configuration is based on the aforementioned low NOx
Similar to the burner 10 except that this low NOx burner 30
In the burner tile 32, the outer shape of the cross section of the portion 32B behind the portion 32A where the cooling oxidant injection hole 34a is formed is the cross sectional shape of the portion where the cooling oxidant injection hole 34a is formed. It is formed so as to be larger than the outer shape, and is formed so as to have the same outer shape as the front surface of the burner main body 31.

The low NOx burner 30 in this example has the same operation and effect as the low NOx burner 10 described above.

Further, as can be seen from FIG. 7, the outer shape of the burner main body of the low NOx burner 30 is made the same as the cross-sectional shape of the mounting opening H1 of the furnace wall H to which the low NOx burner 30 is mounted. When the low NOx burner 30 is inserted and supported in the mounting hole H1, a gap s is formed between the portion 32A of the burner tile 32 where the cooling oxidant injection hole 34a is formed and the inner wall surface of the mounting hole H1. Is secured, and the portion 32B behind the portion 32A of the burner tile 32 covers the front surface of the burner main body 31, so that the front surface of the burner main body 31 is prevented from being exposed in the furnace and heated.

FIG. 9 is a sectional side view showing a fourth example in which the present invention is applied to a burner for a heating furnace having a flame stabilizing plate.

In FIG. 9, the burner 40 for the heating furnace is used.
Is a cooling oxidizing agent injection hole 41 that communicates with the burner tile 41 between the inside of the flame hole 41A and the outer peripheral surface side of the burner tile 41.
B is formed.

Other parts such as the fuel injection pipe 42, the flame holding plate 42A, the oxidizing agent supply port 43 and the like are shown in FIGS.
This is the same as the heating furnace burner described above.

In the heating furnace burner 40, when the combustion is performed, a part of the oxidant supplied from the oxidant supply port 43 is opened at an inner end portion in front of the flame holding plate 42A. The burner tile 41 is ejected to the outer peripheral surface of the burner tile 41 through the cooling oxidant injection hole 41B, and flows toward the front side of the burner tile 41 which is under negative pressure by the injection of the flame F.

Thus, the heating furnace burner 40
During combustion, the oxidizing agent blown to the outer peripheral surface of the burner tile 41 suppresses a rise in surface temperature of the burner tile 41, thereby preventing deformation of the opening,
Steady combustion can be maintained.

FIG. 10 is a side sectional view showing a fifth example in which the present invention is applied to a burner for a heating furnace having a flame stabilizing plate.

The burner body 50 of the heating furnace burner 50
The size of the cross-sectional shape of A is set to be larger in the vertical and horizontal directions than the size of the cross-sectional shape of the burner tile 51, and the rear end of the burner tile 51 fits in the burner main body 50A. Have been combined.

A cooling oxidant supply opening 54 communicated with the oxidant supply port 53 of the burner main body 50A is formed over the entire circumference between the burner main body 50A and the burner tile 51. A part of the oxidant supplied from the oxidant supply port 53 is
4 blows out forward along the outer peripheral surface of the burner tile 51.

The construction of other parts such as the fuel injection pipe 52 and the flame holding plate 52A is the same as that of the heating furnace burner 40.

The burner 50 for the heating furnace is used for combustion.
The oxidizing agent blown to the outer peripheral surface of the burner tile 51 suppresses a rise in the surface temperature of the burner tile 51, thereby preventing the opening from being deformed and maintaining steady combustion.

FIG. 11 is a side sectional view showing a sixth example in which the present invention is applied to a burner for a heating furnace having a flame stabilizing plate.

In FIG. 11, the burner 60 for the heating furnace is used.
The burner tile 61 has a stepped shape in which the outer shape on the rear end side is larger than the outer shape on the front end side, and the outer end side opening of the cooling oxidant injection hole 61B is provided at the front side of this step. It is open. The configuration of other parts is the same as that of the heating furnace burner 40 of FIG.

In the heating furnace burner 60, similarly to the heating furnace burner 40 in FIG. 9, the burner tile 61 is cooled by the oxidizing agent injected from the cooling oxidizing agent injection hole 61B, and can be understood from the drawing. As described above, when the heating furnace burner 60 is inserted and supported in the mounting opening H1 of the heating furnace, the heating furnace burner 60 is injected from the cooling oxidant injection hole 61B between the mounting opening H1 and the outer peripheral surface of the burner tile 61. The flow path of the oxidizing agent is secured.

[Brief description of the drawings]

FIG. 1 is a side view showing a first example in an embodiment of the present invention.

FIG. 2 is a front view of the same example.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is an explanatory diagram showing a mounting state of a low NOx burner of the same example on a furnace wall and a flow of a cooling oxidant.

FIG. 5 is a side view showing a second example in the embodiment of the present invention.

FIG. 6 is a front view of the same example.

FIG. 7 is a side view showing a third example in the embodiment of the present invention.

FIG. 8 is a front view of the same example.

FIG. 9 is a side sectional view showing a fourth example in the embodiment of the present invention.

FIG. 10 is a side sectional view showing a fifth example in the embodiment of the present invention.

FIG. 11 is a side sectional view showing a sixth example in the embodiment of the present invention.

FIG. 12 is a side view showing a conventional example.

FIG. 13 is a front view of the conventional example.

FIG. 14 is a partial side sectional view showing a state where a fuel injection hole and an oxidant injection hole of a conventional low NOx burner are melted and damaged.

FIG. 15 is an explanatory diagram showing a state of adhesion of suspended matter in a conventional example.

FIG. 16 is a side sectional view showing another conventional example.

FIG. 17 is a front view of the conventional example.

[Explanation of symbols]

10, 20, 30 ... low NOx burner 11, 21, 31 ... burner body 12, 22, 32 ... burner tile (refractory) 13, 23, 33 ... fuel injection hole 14, 24, 34 ... oxidant injection hole 14a, 34a: cooling oxidant injection hole (cooling oxidant supply unit) 25: cooling oxidant supply opening (cooling oxidant supply unit) 40, 50, 60 ... heating furnace burners 41, 51, 61 ... Burner tile (refractory) 41B, 61B ... cooling oxidant injection hole (cooling oxidant supply unit) 54 ... cooling oxidant supply opening (cooling oxidant supply unit) H ... furnace wall H1 ... mounting port s ... gap

Claims (4)

[Claims] 1. A heating furnace burner in which a refractory is provided at a front portion of a burner and which burns by injecting a fuel and an oxidant, wherein a part of the oxidant is blown to an outer peripheral surface side of the refractory. A burner for a heating furnace comprising an oxidizing agent supply section for heating. 2. The cooling oxidant supply unit is a cooling oxidant injection hole that opens to the outer peripheral surface of the refractory and is connected to an oxidant supply passage formed in the refractory. Item 2. A burner for a heating furnace according to Item 1. 3. A cross section of a portion of the refractory which is located behind a portion where the cooling oxidant injection hole is provided has a cross section of a portion where the cooling oxidant injection hole is provided. 3. The burner for a heating furnace according to claim 2, wherein the burner is formed so as to be larger than the size of the heating furnace. 4. The cooling oxidant supply opening provided in the burner main body for supporting the refractory and blowing the cooling oxidant forward along the outer peripheral surface of the refractory. The burner for a heating furnace according to claim 1, which is a part.