JP2003279003A - Burner device for cement kiln - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a burner device for a cement kiln, which reduces the generated amount of nitrogen oxides while maintaining the quality of calcinated clinker, maintains mechanical reliability, and facilitates the adjustment for obtaining optimum flame to the type of solid powder fuel to be used or the like. <P>SOLUTION: This burner device for cement kiln 1 comprises: a flow passage 2 for solid powder fuel having a plurality of flow passages in a concentric circle form and a turning means 2a for solid powder fuel flow; a first air flow passage 3 disposed at the outside adjacent to the flow passage 2 for solid powder fuel and having a turning means 3a for air flow; a second air flow passage 4 disposed at the outside adjacent to the first air flow passage; and a third air flow passage 5 disposed at the inside adjacent to the flow passage 2 for solid powder fuel and having a turning means 5a for an air flow. A fourth air flow passage 36 can be also provided between the flow passage 2 for solid powder fuel and the third air flow passage 5. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner device for a cement kiln, which mainly uses a solid fuel such as pulverized coal as a main fuel, and particularly to a flame adjusting function, a change in fuel type, and a furnace operating environment. The present invention relates to a burner device having improved adaptability.

[0002]

2. Description of the Related Art Conventionally, in a cement burning kiln, a burner device in which a fuel flow path and an air flow are concentrically arranged is used to distribute an air amount and a swirling strength to a plurality of air flow paths. Adjustments have been made to the combustion conditions in the kiln.

For example, a pulverized coal burner device disclosed in Japanese Patent Publication No. 4-74603 has a concentric circle for the purpose of performing a slow combustion for improving a flame holding function and suppressing generation of nitrogen oxides. It is a pulverized coal burner device having a plurality of flow paths, and a pulverized coal flow path and two air flow paths adjacent to the pulverized coal flow path are provided inside and outside the air flow path. A means for swirling the flow is provided.

On the other hand, in European Patent No. 421903, the primary air amount is reduced and the flame adjustment range is expanded, thereby contributing to energy saving and suppressing the generation of nitrogen oxides. With multiple channels,
A first air flow path, which is arranged outside adjacent to the solid powder fuel flow path and has a swirling means for air flow, and a second air flow path which is arranged outside adjacent to the first air flow path. A patent has been made on a burner device for a rotary kiln, which has an air flow passage and a third air flow passage that is disposed inside and adjacent to the flow passage for solid powder fuel.

Further, in the above conventional burner device and the like,
When adjusting the amount of air flowing through each air flow path and the swirl strength, swirl vanes fixed in the flow path are used to change the swirl strength in conjunction with the distribution of the amount of air flowing through the air flow path. The turning strength was changed by mechanically moving the turning means such as.

[0006]

However, even with the above-mentioned conventional burner device for cement kiln, it is difficult to use various fuels and to achieve both quality assurance of a wide variety of clinker and reduction of generated nitrogen oxides. However, it has been difficult to obtain a burner device for a cement kiln that exhibits satisfactory performance.

Further, when the combustion state is adjusted in accordance with various fuels and operating environments of the furnace by using the above-mentioned conventional burner device, when the swirl vanes fixed in the flow passage are used, the air flow There is a problem that the amount of air flowing through the road and the turning strength cannot be adjusted independently. Furthermore, since the burner device provided with the movable turning means for changing the turning strength is exposed to high temperature, there is a problem in the reliability of the mechanically moving part.

Therefore, the present invention has been made in view of the problems in the above-mentioned conventional burner device for cement kiln, and reduces the amount of nitrogen oxides generated while maintaining the quality of the clinker to be fired. An object of the present invention is to provide a burner device for a cement kiln that can be used.

Further, in addition to the above, the present invention makes it easier to adjust for obtaining an optimum flame according to the type of solid powder fuel to be used and the operating environment of the furnace while maintaining the mechanical reliability. It is an object of the present invention to provide a burner device for a cement kiln that can be used in the above.

[0010]

In order to achieve the above object, the invention according to claim 1 is a burner device for a cement kiln, which is provided with a plurality of concentric flow paths, and swirls a solid powder fuel flow. A solid powdered fuel flow path having means, a first air flow path disposed outside of the solid powdered fuel flow path adjacent to the solid powdered fuel flow path, and having an air flow swirling means, and the first air flow path. A second air flow path disposed on the outer side adjacent to the flow path, and a third air flow path disposed on the inner side adjacent to the solid powder fuel flow path and having an air flow swirling means. It is characterized by having.

According to the invention described in claim 1,
A first externally disposed adjacent to the solid powder fuel flow path
Swirling means is provided in the air flow path of the solid powder fuel flow path, and a second air flow path is provided outside the first air flow path adjacent to the first air flow path, and swirling means is provided in the solid powder fuel flow path. Since the swirling means is also provided in the third air flow passage disposed inside the air passage adjacent to the passage, the combustibility of the solid powder fuel in the burner device is improved and the quality of the clinker fired in the cement kiln is not deteriorated. Thus, it becomes possible to reduce the amount of nitrogen oxides generated. Further, since two air channels are provided on the outside and one air channel is provided on the inner side of the solid powder fuel channel, it is possible to independently change the amount of air flowing through each channel. It is also possible to easily make adjustments to obtain an optimum flame according to the type of powdered fuel and the like.

According to a second aspect of the present invention, in the burner device for cement kiln according to the first aspect, a fourth air passage is provided between the solid powder fuel passage and the third air passage. It is characterized by having.

According to the invention of claim 2, further,
Since the fourth air flow passage is arranged between the solid powder fuel flow passage and the third air flow passage, two air flow passages are provided outside and two air flow passages are provided inside with the solid powder fuel flow passage interposed therebetween. Since it is equipped with a passage, the number of air passages that can adjust the amount of air independently increases by one, making it easier to obtain the optimum flame according to the type of solid powder fuel used. It can be carried out.

According to a third aspect of the present invention, in the burner device for a cement kiln according to the first or second aspect, the flow rate of the air flowing through the first air flow passage and the flow rate of the second air flow passage. It is characterized in that it is provided with a flow rate control means capable of independently controlling the flow rate of air.

According to the third aspect of the invention, the flow rate of the air flowing through the first air flow path and the flow rate of the air flowing through the second air flow path can be independently controlled. In adjusting the swirling strength of the airflow, the conventional mechanically movable part is not necessary, and the first air flow path mainly for swirling the airflow and the second airflow mainly for straight traveling of the airflow are provided. The swirl strength can be adjusted without changing the overall flow rate of air flowing through the air flow path.

According to a fourth aspect of the present invention, in the burner device for a cement kiln according to the second or third aspect, the flow rate of the air flowing through the third air passage and the fourth air passage. A second flow rate control means capable of controlling the flow rate of air independently of each other is provided.

According to the invention described in claim 4, the flow rate of the air flowing through the third air flow path and the flow rate of the air flowing through the fourth air flow path can be independently controlled. , Not only on the outside of the flow path for solid powder fuel, but on the inside as well, the third air flow path that mainly swirls the air flow and the fourth air flow path that mainly goes straight on It is possible to adjust the swirling strength without changing the air flow rate, and it is possible to more easily perform the adjustment for obtaining the optimum flame according to the type of solid powder fuel used and the like.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A concrete example of an embodiment of the burner device for cement kiln according to the present invention will be described with reference to the drawings.

FIG. 1 and FIG. 2 show a first embodiment of a burner device for cement kiln according to the present invention (hereinafter abbreviated as "burner device"). This burner device 1 has a plurality of concentric circular streams. A channel 2 for solid powder fuel,
A first member disposed outside the solid powder fuel flow path 2 adjacent thereto
Of the air flow path 3, the second air flow path 4 adjacent to the first air flow path 3 on the outside, and the third air flow path 3 adjacent to the solid powder fuel flow path 2 on the inside. 4 in total for the air flow path 5
Equipped with one flow path. In addition, inside the third air flow path 5,
The oil gun 6 and the like are arranged.

Of the four flow paths 2 to 5, the solid powder fuel flow path 2, the first air flow path 3 and the third air flow path 5 are respectively swirling means as swirling means. Blades 2a, 3
a and 5a are fixed.

FIG. 3 shows an embodiment of a combustion system including the burner device 1, and the combustion system 11 includes a first roots blower 12, a fan 13 and a second roots blower 14. The pulverized coal C supplied to the pulverized coal conveying pipe 15 is supplied to the solid pulverized fuel flow passage 2 by the first roots blower 12, and the air from the fan 13 is supplied to the burner device 1 via the air pipes 16, 17, and 18. The air supplied from the second roots blower 14 to the first air passage 3 and the third air passage 5 is supplied to the second air passage 4 of the burner device 1 via the air pipe 19. A damper 21 for controlling the amount of air is provided in the air pipe 20,
Since the air pipe 18 is provided with the damper 21 and the air pipe 17 is provided with the damper 23, the amount of air flowing through each of the flow paths 2 to 5 can be independently controlled. As a result, adjustments can be easily made to obtain an optimum flame according to the type of solid powder fuel such as pulverized coal, petroleum coke and other alternative fuels, and the operating environment of various furnaces.

Next, the burner device 1 having the above structure
A test example of (Example) and a pulverized coal burner device (comparative example) described in Japanese Patent Publication No. 4-74603 will be described with reference to Table 1. The burner primary air ratio, the burner axial direction and the circumferential momentum in each burner device are as described in the lower part of the table. Further, in both Examples and Comparative Examples, the case where ordinary cement is fired is shown as can be seen from the component values of the clinker.

[0023]

[Table 1]

As can be seen from the table, in the examples, while maintaining the free lime of the calcined clinker at a good value, the kiln butt NOx and EPNOx (electric precipitator outlet gas installed downstream of the cement kiln were It can be seen that the nitrogen oxide content) is significantly lower than that of the comparative example. Also, the kiln butt temperature showed almost the same value as the comparative example, and although the oxygen concentration of the kiln butt was lower than that of the comparative example, carbon monoxide was not detected in the kiln butt, and the combustibility in the kiln was It turns out that is not decreasing.

FIGS. 4 and 5 show a second embodiment of the burner device according to the present invention. The burner device 31 is provided with a plurality of concentric flow paths and a solid powder fuel flow path 32.
A first air channel 33 and a second air channel 34 arranged outside the solid powder fuel channel 32, and a third air stream disposed inside the solid powder fuel channel 32. The passage 35 and the fourth air passage 36 are provided with a total of five passages. That is, in the present embodiment, the fourth air passage 36 is further provided between the solid powder fuel passage 2 and the third air passage 5 of the first embodiment.
Has been arranged. An oil gun 37 and the like are arranged inside the third air flow path 35.

Of the five channels 32 to 36, the solid powder fuel channel 32, the first air channel 33, and the third channel
In the air flow path 35 of each of the swirling blades 3 as swirling means.
2a, 33a and 35a are fixed.

Although not shown, in this embodiment as well,
Similar to the combustion system 11 shown in FIG. 3, the plurality of blowers, the plurality of dampers, and the like are configured to independently control the amount of air flowing through the air passages 32 to 35. .

With the above construction, the burner device 31 has the first air flow path 33 and the second air flow path 34 on the outer side and the third air path on the inner side with the flow path 32 for the solid powder fuel interposed therebetween.
Of the air flow path 35 and the fourth air flow path 36 independently of each other, Since the swirling strength can be adjusted without changing, it becomes possible to more easily perform the adjustment for obtaining the optimum flame according to the type of the solid powder fuel used and the like.

[0029]

As described above, according to the burner apparatus of the present invention, it is possible to reduce the amount of nitrogen oxides generated while maintaining the quality of the clinker to be fired, and to improve the mechanical reliability. While maintaining the property, it becomes possible to more easily perform the adjustment for obtaining the optimum flame according to the type of the solid powder fuel used and the like.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of a burner device according to the present invention.

2 is a vertical cross-sectional view of the burner device of FIG. 1 (the thickness of the burner member and refractory material depicted in FIG. 1 are omitted to clarify the cross-sectional structure).

FIG. 3 is a flow chart showing an embodiment of a combustion system including the burner device of FIG.

FIG. 4 is a front view showing a second embodiment of the burner device according to the present invention.

5 is a vertical cross-sectional view of the burner device of FIG. 4 (the thickness of the burner member and refractory material depicted in FIG. 4 are omitted to clarify the cross-sectional structure).

[Explanation of symbols]

1 burner device 2 Solid powder fuel flow path 2a swirl blade 3 First air flow path 3a swirl blade 4 Second air flow path 5 Third air flow path 5a swirl blade 11 Combustion system 12 First Roots Blower 13 fans 14 Second Roots Blower 15 Pulverized coal transport piping 16 air piping 17 Air piping 18 Air piping 19 Air piping 20 air piping 21 damper 22 Damper 23 Damper 31 Burner device 32 Solid powder fuel flow path 32a swirl vane 33 First air flow path 33a swirl vane 34 Second air flow path 35 Third Air Flow Path 35a swirl vane 36 Fourth Air Flow Path 37 oil gun

Continued front page    (72) Inventor Hideto Suzuki             1-22, Kiyosumi, Koto-ku, Tokyo Pacific Ocean             Engineering Co., Ltd. (72) Inventor Takuya Shindo             3-8-1, Nishikanda, Chiyoda-ku, Tokyo             Heiyo Cement Co., Ltd. F term (reference) 3K065 QA01 QB09 QB11 QC02 QC04                       TA01 TB13 TC03 TD07 TE01                       TE10 TJ03 TJ06 TL03                 3K091 AA01 AA05 BB07 BB25 CC13                       CC24 FB22 FB28 FB32 FB44                       FB55 FB66

Claims (4)

[Claims] 1. A burner device for a cement kiln having a plurality of concentric flow paths, the flow path for solid powder fuel having swirling means for the flow of solid powder fuel, and the flow path for solid powder fuel. A first air flow path that is disposed adjacent to the outside and has a swirling means for the air flow; a second air flow path that is disposed outside and adjacent to the first air flow path; A burner device for a cement kiln, comprising: a third air flow path, which is disposed inside and adjacent to the flow path for powder fuel and has a swirling means for air flow. 2. The burner device for a cement kiln according to claim 1, further comprising a fourth air passage between the solid powder fuel passage and the third air passage. 3. A flow rate control means capable of independently controlling the flow rate of air flowing through the first air flow path and the flow rate of air flowing through the second air flow path. The burner device for a cement kiln according to claim 1 or 2, which is characterized. 4. A second flow rate control means capable of independently controlling the flow rate of air flowing through the third air flow path and the flow rate of air flowing through the fourth air flow path. The burner device for a cement kiln according to claim 2 or 3, characterized in that.