JPS5824709A - Fluidized bed furnace - Google Patents

Abstract

PURPOSE:To purge a furnace without lowering the temperature of a fluidized bed, by providing a gas inlet port to purge the furnace to the upper position of a furnace above the surface of a fluidized bed, end by introducing a part of gas to fluidize the bed into the gas inlet port through a branch piping. CONSTITUTION:An air inlet port 9 and an air feed piping 10 to purge a furnace are provided to the upper position on the side wall of a furnace above a fluidized bed 1, which consists of a fluidized bed part 2 and an air cylinder part 3. A purge operation is performed by closing an air inlet valve 8 which fluidizes the bed, and by opening a purge-air check valve 11, to actuate a fan 12 to rotate to blow off the air for purge. During this operation, the temperature of the fluidized bed will not be decreased, because the air for purge does not pass through the fluidized bed part 2. The furnace can be purged throughly, since the purging operation is taken place with the air cylinder part 3 as its target only.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluidized bed combustion furnace, and more particularly to a fluidized bed combustion furnace provided with a gas inlet for purging the inside of the furnace.

In a fluidized bed combustion furnace (for example, a fluidized bed boiler), when the operation is temporarily stopped and then restarted, the inside of the furnace must be purged with gas (usually air) to create an oxidizing atmosphere. Conventionally, such furnace purging has been carried out by introducing fluidizing air from the bottom of the fluidized bed. For this reason, there was a drawback that the temperature of the fluidized bed decreased extremely during purging inside the furnace, a large amount of fuel was consumed during startup, and startup time became longer.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide a fluidized bed combustion furnace in which the inside of the furnace can be purged without lowering the fluidized bed temperature.

The present invention achieves the above object by providing a purge air inlet above the layer surface of an RTm layer combustion furnace, and purging the inside of the furnace in a hollow cylindrical portion above the layer surface.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a system diagram of a fluidized bed combustion furnace (for example, a fluidized bed boiler) showing an embodiment of the present invention. In FIG. , fluidized bed section 2
Air is blown into the fluidizing air pipe 5 through the air distribution plate 4 to fluidize the medium and fuel in the fluidized bed. The piping 5 is provided with a fluidizing air control valve 6, an air fan 7, and an air population valve 8. On the other hand, a purge air inlet 9 and an air pipe 10 are provided on the furnace side wall above the fluidized bed, and the pipe is further provided with a purge air valve 11 and an air fan 12.

In the above configuration, when purging the furnace 5, the fluidizing air population valve 8 is closed, the purge air stop valve 5 is opened while the fluidizing air 7 is stopped, and the purge air fan 12 is opened.
Activate. Since the inside of the furnace can be purged by targeting the hollow cylindrical portion, the inside of the furnace can be sufficiently purged by the above operation.

In addition, since the purge air does not pass through the fluidized bed section 2, the purge air does not pass through the fluidized bed section 2.
1. It is possible to purge the inside of the furnace at the time of restart without lowering the temperature.

FIG. 2 shows another embodiment of the present invention, in which the same parts as in FIG. 1 are designated by the same reference numerals.
The purge air fan 12 has the following features: a branch pipe 13 is provided in place of the purge air fan 12, a part of the flowing air is used as the purge air, and a plurality of purge air inlets (9 and 9A) are provided. By eliminating the
By saving operational effort and cost, and by providing a plurality of purge air inlets, the entire middle cylinder can be effectively purged.

As described above, according to the present invention, it is possible to purge the inside of the furnace while avoiding a drop in Km temperature as much as possible when restarting the fluidized bed twisting φ furnace once it has been stopped, thereby shortening the restart time and consuming fuel for startup. The amount can be reduced.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a fluidized bed combustion furnace showing one embodiment of the present invention, and FIG. 2 is a similar system diagram showing another embodiment of the invention. DESCRIPTION OF SYMBOLS 1... Fluidized bed combustion furnace, 2... Fluidized bed part, 3... Cavity part, 7... Air fan for fluidization, 8... Air population valve for fluidization, 9... Purge air Inlet port, 11...Purge air stop valve, 12...Purge air fan. Agent Patent Attorney Takenaga Kawakita

Claims (1)

[Claims] (1) A fluidized bed combustion furnace comprising a fluidized bed combustion apparatus having a hollow cylinder part and a fluidized bed part, characterized in that a gas inlet for purging the furnace is provided above the surface of the fluidized bed. (2. A fluidized bed combustion furnace according to claim 1, characterized in that a branch pipe is provided for introducing a part of the fluidizing gas as a purge gas into the purge gas inlet.