JPH0220574Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a coal burner nozzle, which is a combustion device for a coal-fired boiler, for example.

A conventional example will be explained below with reference to FIGS. 1 and 2.

1 and 2 show a conventional coal burner nozzle. This coal burner nozzle has a nozzle body 1 made of stainless steel with multiple grooves 2 formed therein, and a rectifying plate 3 made of high Cr cast iron or stainless steel cast iron.
It is constructed by removably inserting...

In this coal burner nozzle, pulverized coal that has been pulverized in a mill passes through a baffle plate 3 from a pulverized coal supply pipe (not shown) connected to a nozzle body 1, is blown into a furnace, and is combusted. In other words, pulverized coal is indicated by arrow A
It flows in the direction from (upstream) to B (downstream).

Therefore, as shown in Fig. 2, the rectifier plate 3 near the furnace
The temperature of the front part 3a of the furnace is 1000℃ due to the combustion flame of the furnace.
The temperature rises to nearly ℃. In addition, since the pulverized coal becomes a high-speed powder slurry and flows along the current plate 3,
Erosion is likely to occur in the current plate 3. Therefore, if the entire baffle plate 3 is made of a single plate and is made of wear-resistant material such as high Cr cast iron, the temperature difference between the front part 3a and the rear part 3b of the baffle plate 3 will be low because the material has almost no ductility. As a result, thermal stress is generated, and this thermal stress causes cracks c from the corner portion 3c of the rectifier plate 3.
This can cause debris to fall into the furnace, damaging the tube and reducing combustion efficiency.

Furthermore, if the entire rectifier plate 3 is made of a single plate and made of heat-resistant material such as cast stainless steel,
Erosion resistance is inferior to the aforementioned high Cr cast iron.

Therefore, the degree of wear due to erosion caused by pulverized coal is greater than that of high Cr cast iron, and its life is about half that of high Cr cast iron.

The present invention was developed based on the above points, and the purpose is to provide a coal burner nozzle that has high thermal shock resistance, does not cause cracking of the current plate during use, and has high wear resistance. be.

In other words, the coal burner nozzle according to the present invention is
In a coal burner nozzle that includes a multi-stage nozzle body and a plurality of rectifying plates that are removably inserted through grooves formed in the nozzle body, a connecting part between the front and rear of the rectifying plates is provided. This configuration has a slope portion that gradually increases toward the front side.

Embodiments of the present invention will be described below with reference to FIGS. 3 to 5. FIG. 3 is a plan view of the current plate according to this embodiment, FIG. 4 is a side view, and FIG. 5 is a front view. Note that the same parts as in the prior art will be described with the same reference numerals. The front portions 13a of the current plates 13 protrude on both sides to be inserted into the grooves 2 of the nozzle body 1, and corner portions 13c are formed between them and the rear portions 13b. The front part 13a and the rear part 13b
The front part 1 is located in front of the corner part 13c between
A slope portion 13d is formed on the side 3a, the slope portion 13d gradually increasing at an inclination angle of, for example, 5° or more. As shown in FIGS. 4 and 5, the slope portions 13d are formed on both sides of the current plate 1 in the thickness direction.

According to the above configuration, the slope portion 13d gradually increases from the rear portion 13b of the current plate 1 to the front side at an inclination angle of 5° or more.
Since the high-temperature part and the low-temperature part are not on the same plane, restraint on thermal deformation is reduced. Therefore, the thermal stress generated in the rectifier plates 13 is reduced, making it possible to effectively prevent cracks from occurring on the surfaces of the corner portions 13c. Therefore, even when a material with almost no ductility, such as high Cr cast iron, is used, cracking can be prevented, and a coal burner nozzle with high thermal shock resistance and excellent wear resistance can be obtained.

Note that it is effective that the slope portion 13d has an inclination angle of 5° or more and gradually changes.

As described in detail above, the coal burner nozzle according to the present invention includes a multi-stage nozzle body and a plurality of rectifier plates that are removably inserted through grooves formed in the nozzle body. , a sloped portion that gradually reaches the front side is formed at the joint between the front and rear parts of the current plate.

Therefore, it is possible to reduce the thermal stress generated in the current plate and prevent the occurrence of cracks on the corner surface, making it possible to use a wear-resistant material with almost no ductility, which has high thermal shock resistance and wear resistance. It is possible to provide a coal burner nozzle with excellent properties.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams showing conventional examples.
Figure 2 is a perspective view of a coal burner nozzle, Figure 2 is a perspective view of a rectifier plate, Figures 3 to 5 are views showing embodiments of the present invention, Figure 3 is a plan view of the rectifier plate, and Figure 4 is a perspective view of the rectifier plate.
The figure is a side view of the current plate, and FIG. 5 is a front view of the current plate. DESCRIPTION OF SYMBOLS 1... Nozzle body, 2... Groove part, 13... Current plate, 13a... Front part of the current plate, 13b... Rear part of the current plate, 13c... Corner part, 13d... Gradient part.

Claims (1)

[Scope of utility model registration request] In a coal burner nozzle that includes a multi-stage nozzle body and a plurality of rectifier plates that are removably inserted through grooves formed in the nozzle body, the width of the rectifier plates that are inserted into the grooves of the nozzle body. A corner part is formed between the wide front part and the rear part, which is narrower than the front part, and the front part is thicker than the rear part, and a slope part that gradually increases toward the front part is formed at the corner. A coal burner nozzle featuring