JP2001027405A - Assist burner for fluidized bed type incinerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the melting and deposition of an in-furnace suspended matter on an inner circumferential surface of a penetration in a furnace wall on which an assist burner is mounted. SOLUTION: This assist burner comprises a burner body 11 having a primary air introduction space 22 for combustion and a secondary air introduction space 24 for combustion, an outer cylinder 12 comprising a cylindrical body with both ends open, and communicating a rear end opening with the secondary air introduction space 24, an inner cylindrical body 13 comprising a cylinder with both ends open and communicating a rear end opening with the primary air introduction space 22, a fuel feed pipe 14 which is arranged in a center of the inner cylinder 13 through an end face plate 35 of the burner body 11 and has a flame holder 36 on an outer circumferential part of a tip located in the inner cylinder 13, a turning blade 37 provided backward of the flame holder 36, and a pilot burner 15 which is extended before the flame holder 36 through the end face plate of the burner body 11 nd provided ignitable to a fluid flowing out of the fuel feed pipe 14. The assist burner 1 is formed so that the tip of the burner is located within a penetrating hole 27 in the furnace wall.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary burner for a fluidized bed incinerator.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, a fluidized bed incinerator is provided with an auxiliary burner to increase the temperature of fluidized sand when starting the furnace or to increase the furnace temperature when the furnace temperature is lowered. 51 are provided. The auxiliary burner 51 includes a burner body 54 forming a combustion air introduction space 53 to which combustion air is supplied from a combustion air inlet 52, a burner tile 57 attached to the burner body 54, and a burner tile 57. It has a tubular body 58 attached to the rear end, the rear end of which is separated from the end face plate 54a of the burner body 54, and an oil sprayer 60 having a double pipe structure located at the center of the burner tile 57. The auxiliary burner 51 is connected to the furnace wall 55.
Is fixed to the furnace wall through-hole 56 formed in the above. In addition,
The burner tile 57 has a tapered shape, that is, a narrowed portion 59, and the furnace wall through-hole 56 has a divergent shape from the tip of the burner tile 57 toward the inside of the furnace.

[0003] Fuel oil is supplied into an inner pipe 61 of the oil sprayer 60, and compressed atomizing air is supplied to an annular space between the inner pipe 61 and the outer pipe 62. Then, the combustion air is mixed with the atomized fluid in which the fuel oil sprayed from the tip of the oil sprayer 60 and the spray air are mixed, so that a desired combustion reaction is maintained. I have.

In this kind of auxiliary burner 51, a position where the fluidized bed can be efficiently heated and heated, that is, the flame reaches the fluidized bed surface,
And it is installed at a position diagonally above the fluidized bed surface in consideration of entrainment of the fluidized sand and abrasion due to the fluidized sand. By the way, there is an auxiliary burner using gas fuel, but in general, a type using oil fuel such as the above-described auxiliary burner 51 is widely used from an economic viewpoint. The combustion capacity of the auxiliary burner 51 depends on the capacity of the fluidized bed incinerator, but generally requires a combustion capacity capable of raising the temperature of the fluidized bed to 800 to 900 ° C.

[0005]

SUMMARY OF THE INVENTION The above-mentioned auxiliary burner 5
Reference numeral 1 denotes an atomizing fluid (mixture of fuel oil and atomizing air) from an oil sprayer 60 and a combustion air inlet 5 which are disposed at an inlet of a furnace wall through-hole 56 formed in a divergent shape.
The combustion air from the furnace 2 is stirred and mixed in the narrowed portion 59 of the burner tile 57 to start combustion, and the furnace wall penetration 5
A flame is also formed from the opening at the tip end of the furnace 6 into the furnace. Therefore, the temperature of the inner peripheral surface of the furnace wall through hole 56 becomes high, and the floating material in the furnace accompanies the inside of the furnace wall through hole 56 by the action of the momentum of the jet flame. This phenomenon is considered to be due to a kind of Coanda effect, and the suspended matter drawn into the furnace wall penetration 56 accumulates on the inner peripheral surface of the furnace wall penetration 56 as shown by a hatched portion I in FIG. As a result, the opening of the furnace wall penetration 56 becomes narrow, and as a result, the combustion cannot be sustained, which causes a problem that the operation of the incinerator must be stopped urgently.

Further, since the auxiliary burner 51 is turned on and off, the suspended matter in the furnace wall penetration 56 adheres to the inner peripheral surface of the furnace wall penetration 56 when the combustion is stopped, and the same problem as described above occurs. . SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and it is an object of the present invention to prevent the in-furnace suspended matter from melting and accumulating on the inner peripheral surface of a furnace wall through-hole where an auxiliary burner is mounted. It is an object of the present invention to provide an auxiliary burner for a fluidized bed incinerator which is made possible.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention comprises a burner body having a primary air introducing space for combustion and a secondary air introducing space for combustion, and a cylindrical body having both ends opened. An outer cylinder body having an end opening communicating with the secondary air introduction space, a cylinder having both end openings, an inner cylinder body having a rear end opening communicating with the primary air introduction space, and an end face plate of the burner body. A fuel supply pipe which is disposed at the center of the inner cylinder and has a flame holding plate at the outer periphery of the tip located in the inner cylinder, a swirl vane provided behind the flame holding plate, and a burner body. A pilot burner extending through the end face plate to a position short of the flame holding plate, and the burner tip is located in the furnace wall through-hole.

[0008]

Next, an embodiment of the present invention will be described with reference to the drawings. 1 to 3 show an auxiliary burner 1 for a fluidized bed incinerator according to the present invention. This auxiliary burner 1 of a tileless type not using a burner tile has a burner body 11, an outer cylindrical body 12, an inner cylindrical body 13, A fuel supply pipe 14 and a pilot burner 15 are provided. Burner body 1
1 has a primary air inlet space 22 to which primary air for combustion is supplied from a primary air inlet 21 and a secondary air inlet space 24 to which secondary air for combustion is supplied from a secondary air inlet 23. The primary air introduction space 22 and the secondary air introduction space 24 are partitioned by a partition plate 25. Usually, the primary air and the secondary air are supplied at a ratio of about 7 to 3.

The outer cylinder 12 is a cylindrical body having a predetermined length and both ends open and fixed to the burner body 11 so that the rear end opening is located in the secondary air introduction space 24. The inner cylindrical body 13 is a cylindrical body having both ends open and having a predetermined length. The inner cylindrical body 13 is arranged at a predetermined interval in the outer cylindrical body 12, and a rear end opening is located in the primary air introduction space 22.
It is attached through the partition plate 25 so that the distal end opening is located near the rear of the distal end of the outer cylindrical body 12. The outer cylinder 12 and the inner cylinder 13 form a secondary air flow path, and the inside of the inner cylinder 13 serves as a primary air flow path.

The fuel supply pipe 14 has a double pipe structure, is disposed at the center of the inner cylinder 13 through the end face plate 35 of the burner body 11, and is located at the outer periphery of the tip located inside the inner cylinder 13. It has a flame plate 36. The inner pipe 31 serves as a flow path for the fuel oil supplied from the oil inlet 32, and sprays the fuel oil from a nozzle hole (not shown) at the front end.
The annular space between the outer tube 1 and the outer tube 33 serves as a flow path for compressed spray air supplied from the spray air inlet 34, and this spray air is ejected from a nozzle hole (not shown) at the tip. I have. Then, the fuel oil from the nozzle hole at the distal end of the inner pipe 31 and the spray air from the nozzle hole at the distal end of the spray air flow path are mixed to form an atomized fluid. In addition, as an oil fuel, for example, kerosene, light oil, A to
C heavy oil or waste oil is used, and steam may be used instead of the atomizing air. Further, in an annular space between the fuel supply pipe 14 and the inner cylinder 13, there is provided a swirling blade 37 located behind the flame holding plate 36.

The primary air for combustion in the inner cylinder 13 passes through the swirling blades 37 to form a swirling flow, and flows out toward the tip of the burner. On the other hand, the secondary air for combustion between the outer cylinder 12 and the inner cylinder 13 flows out straight from the burner tip. The pilot burner 15 has a double pipe structure like the fuel supply pipe 14 and is located in the inner cylinder 13.
The inner pipe 41 serves as a flow path for ignition gas supplied from a gas inlet 42, and an annular space between the inner pipe 41 and the outer pipe 43 forms a flow path for combustion air supplied from a combustion air inlet 44. It has become. A high-pressure cord is inserted into the pilot burner 15 from a high-pressure cord inlet 45, thereby generating a spark at the tip of the pilot burner 15 and igniting a mixed fluid of gas and fuel air, which is used as an ignition source. The atomized fluid from the fuel supply pipe 14 is ignited to start combustion. The burner body 11 is provided with a sight hole 46 and a flame monitor 47 for monitoring the flame.

Here, as the flame holding plate 36, a strong swirling type illustrated in FIG. 3 is used, and a part of the primary air is strongly swirled by the flame holding plate 36. The flame stabilizing plate 36 exerts the first-stage flame stabilizing action at the outlet of the fuel supply pipe 14, and furthermore, the swirling blades 37 turn the entire primary air into a swirling flow to exert the flame stabilizing action on the entire flame. It has become. As described above, in the auxiliary combustion burner 1, in addition to stabilizing the combustion by causing a double flame holding action, in addition to the swirl flame, the exhaust gas in the furnace is entrained by the swirling flame, and the self-exhaust gas circulation causing the oxygen-lean combustion. As a result of the structure, reduction of NOx in exhaust gas is also realized.

The burner burner 1 is fixed so as to extend into the furnace wall through-hole 27 so that the tip of the burner is located near the tip inside the furnace wall through-hole 27. The inner peripheral surface of the furnace 27 is prevented from becoming high temperature, and the floating material in the furnace is hardly caught in the furnace wall through-hole 27. Furthermore, the secondary air for combustion that flows out as a straight stream from the tip of the burner also acts to blow off the suspended matter, and the secondary air lowers the temperature of the flame,
The suspended matter is less likely to melt in the flame. As a result, a situation in which the suspended matter in the furnace is melted and deposited on the inner peripheral surface of the furnace wall through hole 27 is suppressed.

By reducing the ratio of the primary air for combustion to the ratio between the primary air and the secondary air described above, the combustion can be delayed and the flame lengthened. Since the auxiliary burner 1 supplies the primary air and the secondary air in two stages, the length of the flame can be adjusted and the two-stage combustion can be achieved by appropriately adjusting the distribution of the two. This makes it possible to reduce NOx in exhaust gas. Although the above-described auxiliary burner 1 is of an oil sprayer type using fuel oil, the present invention also provides an auxiliary burner using a gas gun type using gas fuel instead of the oil sprayer type. Including.

[0015]

As is apparent from the above description, according to the present invention, a burner body having a primary air introducing space for combustion and a secondary air introducing space for combustion, and a cylindrical body having both ends open, are provided. An outer cylinder body having an opening communicating with the secondary air introduction space, an inner cylinder body comprising a cylinder having both ends opened, and a rear end opening communicating with the primary air introduction space, and an end cylinder of the burner body passing through the end face plate. It is located at the center of the inner cylinder,
A fuel supply pipe having a flame stabilizing plate at a distal end outer peripheral portion located in the inner cylinder, a swirling blade provided behind the flame stabilizing plate, and extending through the inner cylinder to a position short of the flame stabilizing plate; A pilot burner provided so as to be able to ignite the fluid flowing out of the fuel supply pipe, and the tip of the burner is located in the furnace wall through-hole.

As described above, the tip of the burner is positioned inside the furnace wall through-hole, and the primary air for combustion among the combustion air is swirled, while the secondary air for combustion is straight.
Since it is designed to burn while being ejected, it is possible not only to prevent the in-furnace floating substances from melting and accumulating on the inner peripheral surface of the furnace wall penetration, but also to reduce NOx in exhaust gas. This has the effect of becoming

[Brief description of the drawings]

FIG. 1 is a view showing a cross section of an auxiliary burner according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view showing an example of a flame holding plate in FIG. 1;

FIG. 4 is a view showing a cross section of a conventional auxiliary burner.

[Description of Signs] 1 Auxiliary burner for fluidized bed incinerator 11 Burner body 12 Outer cylinder 13 Inner cylinder 14 Fuel supply pipe 15 Pilot burner 22 Primary air introduction space 24 Secondary air introduction space 27 Furnace wall penetration port 35 End Face plate 36 Flame holding plate 37 Rotating blade

Claims (1)

[Claims] 1. A burner body having a primary air introduction space for combustion and a secondary air introduction space for combustion, and an outer cylinder body comprising a cylindrical body having both ends opened, and having a rear end opening communicating with the secondary air introduction space. An inner cylinder body, which is formed of a cylinder having both ends open and communicates a rear end opening to the primary air introduction space, and is disposed at the center of the inner cylinder through an end face plate of the burner body, and is disposed in the inner cylinder. A fuel supply pipe having a flame stabilizing plate at the outer peripheral end located at the tip, a swirling blade provided behind the flame stabilizing plate, and a pilot burner extending through the end face plate of the burner body to a position short of the flame stabilizing plate. A combustion burner for a fluidized-bed incinerator, wherein the burner tip is located in the furnace wall through-hole.