JPS602408Y2 - call burner - Google Patents

Description

[Detailed description of the invention] A coal burner, so-called a burner that burns coal, consists of a coal packet that ejects a pulverized coal-air mixture that is a mixture of pulverized coal and primary air, and an air that ejects only secondary air. It consists of a nozzle.

The pulverized coal ejected from the coal packet along with the primary air is ignited by the radiant heat from inside the furnace, and at the initial stage of ignition, combustion progresses while consuming oxygen from the primary air, and combustion is completed while consuming oxygen from the secondary air. .

A coal burner with such a configuration burns various types of coal with various characteristics, but -! The properties of Nyoko coal are wide-ranging, and some coals have special properties, so even though the basic structure of a coal burner remains the same, various improvements have been made in actual combustion for combustion and pollution control purposes. It is used in addition.

The present invention relates to a coal burner for burning highly cohesive coal.

A conventional first coal burner will be specifically explained based on FIGS. 1 and 2.

In FIG. 1, 01 is an air passage in an air compartment, 02 is an air passage in a coal compartment, 03 is a fuel pipe, 04 is an air nozzle, 05 is a coal nozzle, and 06 is a coal packet.

The pulverized coal-air mixture passes through a fuel pipe 03 and is ejected from a coal packet 06 of a coal nozzle 05.

On the other hand, the high temperature secondary air passes through the air compartment 01 and the air passage 02 of the coal compartment, respectively.
Coal packet 0 for air nozzle 04 and coal nozzle 05
6. Sprayed into the furnace from the surrounding area.

Immediately after the pulverized coal is ejected from the coal packet 06, it is ignited and combusted by the radiated heat from inside the furnace.

At this time, each nozzle 04.05 of the coal burner receives radiant heat from inside the furnace and reaches a relatively high temperature state.

The pulverized coal-air mixture is supplied to the coal packet 06 through the mixture passage 07 of the fuel pipe 03, and is injected into the furnace through the coal packet passage 08.

On the other hand, high-temperature secondary air passes through the air passage 02 of the coal compartment and reaches the coal nozzle 05 and the coal packet 0.
The air is fed into the furnace through a peripheral air passage 09 between the 6 and 6 holes.

In the coal packet 06 having such a structure and operation, the temperature of the coal packet 06 becomes considerably high due to the radiant heat from inside the furnace and the high temperature secondary air flowing around the coal nozzle 06.

When highly caking coal is burned, pulverized coal adheres to the inner wall of the coal packet 06, gradually accumulates and grows, and finally blocks the coal packet passage 08, leading to unstable combustion or misfire.

A conventional coal burner that is an improved version of the coal burner that has the possibility of clogging is shown in FIGS. 3 and 4.

3 and 4, 11 is an air passage in the air compartment, 12 is an air passage in a coal compartment, 13 is a fuel pipe, 17 is a pulverized coal-air-mixture passage, 15 is a coal nozzle, and 15 is a coal nozzle. Air passages 19 and 16 are call packets, 18 is a call packet passage, 20 is a cooling air passage, 21 is a cooling air jet hole, and 34 is an air nozzle.

The flow of the pulverized coal-air mixture of the coal packet 16 from the fuel pipe 13 and the flow of the secondary air are the first
Although the call burner is similar to the call burner shown in FIGS.
This differs from the coal burner shown in FIGS. 1 and 2 in that a cooling air jet hole 21 is provided around the outer periphery of the cooling air passage 20, and cooling air from a cooling air passage 20 is supplied and jetted from the cooling air jet hole 21.

Since this cooling air cools the outer wall surrounding the coal packet 16, it is possible to suppress the inner surface temperature of the coal packet 16 to below the pulverized coal adhesion temperature and prevent pulverized coal from adhering and accumulating on the coal packet 16.

However, this call burner has the following drawbacks.

In order to suppress the inner surface temperature of the coal packet 16 to below the pulverized coal adhesion temperature, a large amount of cooling air is required.

However, this large amount of cooling air is ejected closely from around the coal packet 16 and contributes to the initial combustion of the pulverized coal, resulting in a problem that the amount of NOx generated during pulverized coal combustion increases.

Therefore, the present invention has been made with the aim of eliminating the drawbacks of the conventional coal burner described above, that is, providing a coal burner that can more effectively prevent the adhesion of pulverized coal without increasing the amount of NOx generated. The present invention provides a coal burner consisting of a coal packet that spouts out a mixture of pulverized coal and primary air, and an air nozzle that jets out only secondary air. The present invention provides a coal burner equipped with a coal packet having a structure for blowing out a small amount of cooling air from holes into a mixture of pulverized coal and primary air.

According to the coal burner of the present invention, by injecting cold air from the pores distributed in the peripheral wall of the coal packet,
The pulverized coal that tends to adhere to and accumulate on the surrounding wall of the coal packet is blown away, returned to the main flow of the pulverized coal-air mixture, and flowed together with the mixture. This prevents pulverized coal from adhering to the coal packet and injects it from the pores. Since the amount of cooled air is small, combustion is not disturbed and NOx generation can be prevented.

Next, the present invention will be explained with reference to an embodiment shown in FIGS. 5 and 6.

31 is an air passage in the air compartment, 32 is an air passage in the coal compartment, 33 is a fuel pipe, 37 is a pulverized coal-air mixture passage, 35 is a coal nozzle, 39 is an air passage in the coal nozzle, 36 is a coal packet, 38 is a pulverized coal-air mixture passage of the coal packet, 40 is a cooling air passage, 41 is a cooling air chamber, 4
2 is a pore for cooling air injection.

In this coal burner, the flow of the pulverized coal-air mixture in the coal packet 36 and the air flow in the air passage 32 of the coal compartment are the same as in the coal burner, so a detailed explanation will be omitted here.

The coal burner was provided with fine holes 42 for cooling air injection distributed in the peripheral wall of the coal packet 36.

Cooling air is ejected from the pores 42 to the pulverized coal-air mixture passage 38 of the coal packet 36 through the cooling air passage 40 and via the cooling air chamber 41 .

The present coal burner having such a structure and operation has the following advantages.

(1) The jet of cold air injected from the pores 42 distributed on the peripheral wall of the coal packet 36 blows away the pulverized coal that is about to adhere to and accumulate on the peripheral wall of the coal packet 36, or mixes the pulverized coal with air. Since the pulverized coal flows back into the air stream, adhesion of pulverized coal to the peripheral wall of the coal packet 36 can be prevented.

(2) The amount of cold air injected from the pores 42 is smaller than that of conventional air-cooled coal burners, so it does not disturb combustion.
Further, the amount of NOx generated can be prevented.

Note that pores 42 are dispersedly opened in the call packet 36.
It is preferable that the holes are inclined toward the opening of the coal packet 36 so as not to disturb the flow of the pulverized coal-air mixture within the coal packet 36.

Although the present invention has been specifically explained above based on one embodiment, it goes without saying that the present invention is not limited to this embodiment.

[Brief explanation of the drawing]

1 and 3 are side sectional views of a conventional coal burner, FIGS. 2 and 4 are front views of FIGS. 1 and 4, respectively, and FIG. 5 is a side view of an embodiment of the present invention. The sectional view, FIG. 6, is a front view of FIG. 5. 01.11,31...Air passage of air compartment, o2,12,32...Air passage of call compartment, 03. 13. 33... Song fuel pipe, 04. 14.34・Song・Air nozzle, 05
, 15.35・Song・Coal Nozzle, 06°16.36・
...Call packet, 07, 17, 37...
・・Mixture passage, 08, 18, 38 ・・Call packet passage, 09, 19, 39・・Tune/Air passage, 20.40
......Cooling air passage 41・Curve・Cooling air chamber, 42...Pore.

Claims (1)

[Scope of utility model registration request] In a coal burner that is composed of a coal packet that spouts a mixture of pulverized coal and primary air, and an air nozzle that spouts only secondary air, the pulverized coal and primary air are A coal burner equipped with a coal packet having a structure for blowing out a small amount of cooling air into a mixture with air.