JPS634081B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a fluidized bed boiler.

In general, fluidized bed boilers have many advantages such as the small space occupied by the equipment, high combustion efficiency, instantaneous and uniform dispersion of processed materials, uniform temperature distribution, and advantages in terms of pollution control. , research on this topic has become active in recent years.

Since a fluidized bed boiler is designed by selecting a hearth load to a predetermined value from the viewpoint of combustion efficiency, the hearth area increases as the boiler capacity increases. Therefore, when forming a fluidized bed with a single flat bed, there is a limit to the boiler capacity due to the bed structure and restrictions on the installation area, making it difficult to increase the size of the bed. This method was adopted to increase the size of fluidized bed boilers.

The present invention relates to the structure of a stack type fluidized bed boiler, and to explain its embodiments, firstly, because a plurality of fluidized bed beds and spaces directly above them (hereinafter referred to as combustion chambers) are stacked, the frame structure is 1, and vertical partition walls A, B, C, ... are suspended from this frame 1 to form a vertical heat transfer surface and support all beds including the necessary air distribution plates and wind boxes. . Figure 1 shows the fluidized bed bed moved to one side.
A common flow path 5 for combustion gas is placed next to it, and it has combustion chambers 11, 12 on the first floor and combustion chambers 14, 18, 20 on the second, third, and fourth floors. A common flow path 5 for exhaust gas is arranged in the center, and a plurality of stages of fluidized bed beds 4 are provided on both sides of the common flow path 5. That is, combustion chambers 11, 12, and 13 are arranged on the first floor, and combustion chamber 1 is arranged on the second, third, and fourth floors directly above the combustion chamber 11.
4, 18, and 20, and combustion chambers 17 and 19 are provided on the second and third floors, respectively, directly above the combustion chamber 13, and the central combustion chamber 12 also serves as a common flow path 5 for combustion gas.

The weight of the boiler is suspended by frame 1,
The individual partition walls A, B, C, D, E, and F are not only heat exchanger tube walls but also constituent members of the boiler, and are attached to the air distribution plate 3 and the wind box 2. It is also supported through the partition wall. Combustion gases from each bed 4 are collected in a common flow path 5 and directed to a rear flue 6. In this structure, as the number of beds increases, the gas flow velocity in the common flow path 5 increases as the amount of combustion gas coming out of the fluidized bed increases toward the top. The gas flow rate of is suppressed to a certain value. Therefore, the gas flow velocity at the bottom of the common flow path becomes slower;
There is a risk that the design will be wasteful in terms of space utilization.

The present invention has been further devised in view of the above, and an embodiment of the present invention will be explained using a four-layer fluidized bed boiler shown in FIG. As in FIGS. 1 and 2, each vertical component member A, B, C... of the boiler is opened from the frame 1.
...H is suspended and supported. The fluidized bed bed 4 has four layers, and a wind box 2 is provided under each bed. There is a fluidized bed bed in the lowest layer between the vertical components A to F, and combustion chambers 11, 1 are provided in the lowest layer (first floor).
2 and 13 are constructed. The central combustion chamber 12 forms a gas flow path in its upper part, and serves as a combustion gas flow path for the combustion chambers 11 and 13 to form a common flow path 5 . or,
The combustion chamber located on the second floor forms a fluidized bed between the vertical members A to C and between D and F, and is divided into combustion chambers 14 and 15, 16 and 17, respectively. The combustion chambers 15 and 16 near the center are on the first floor (lowest floor) above.
It is adjacent to the central common flow path 5, which is a common flow path for the combustion chambers 11, 12, and 13, and serves as a common flow path 5' for combustion gas in the combustion chambers on the second floor and above. That is, the combustion chamber 1
The flow path formed above the combustion chamber 16 becomes the combustion gas common flow path 5' for the combustion chambers 14 and 15 on the second floor and the combustion chamber 18 on the third floor, and the flow path formed above the combustion chamber 16 becomes the combustion gas common flow path 5' for the combustion chambers 14 and 15 on the second floor and the combustion chamber 18 on the third floor. 16, 17 and the combustion chamber 19 on the third floor.Each common channel 5, 5', 5'' is combined into one at the fourth floor position, and the entire combustion gas is transferred to the rear. It is discharged from the flue 6.

In a fluidized bed boiler with a fluidized bed configured in this way, the area of the fluidized bed is gradually reduced toward the upper layer, and the number of common flow paths is increased. In contrast, in the boiler shown in FIG. 3, the combustion gas flow path is expanded and the superficial velocity is not so restricted in the boiler shown in FIG.

In the case of the conventional fluidized bed boiler shown in Figure 2, the ratio of the common flow path to the total boiler volume is estimated as follows:
The ratio is approximately 0.428, whereas it is approximately 0.364 in the case of FIG. The combustion function can be achieved with 15% less common flow volume.

Although the present invention is a high-rise boiler as described above, the main components are suspended from the frame in a focused manner, so the load on the cargo owner on the lowest combustion chamber is reduced, while the boiler is a large-capacity fluidized bed boiler. This is an extremely excellent technical invention that can be constructed without reducing combustion efficiency.

[Brief explanation of the drawing]

1 and 2 are side views of a stack type fluidized bed boiler, and FIG. 3 is a side view of a stack type fluidized bed boiler showing an embodiment of the present invention. 1... Frame, 2... Wind box, 3... Air dispersion plate,
4... Fluidized bed bed, 5, 5', 5''... Common flow path, 6... Rear flue, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20... Combustion chamber, A, B, C......H... Members suspended from the frame 1.

Claims (1)

[Claims] 1. In a so-called stack-type fluidized bed boiler in which combustion chambers having fluidized bed beds are stacked, the fluidized bed beds are designed such that the flow path cross-sectional area of the combustion gas from the plurality of fluidized bed beds gradually expands in the flow direction of the combustion gas. A fluidized bed boiler characterized in that the area gradually decreases toward the upper layer.