JP2671991B2 - Fluidized bed combustion equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fluidized bed combustion apparatus, and in particular, uses a solid fuel such as coal or petroleum coke, and a main combustion fluidized bed furnace (MBC).
Fluidized bed furnace (CB) for burning unburned ash discharged from
C) Installed fluidized bed combustor.

[Conventional technology]

The prior art will be described with reference to FIG. Main combustion fluidized bed furnace 1
Combustion ash of solid fuels such as coal burned in the form of fly ash is discharged together with the combustion gas, and the economizer 15, multi-cyclone 3, denitration device 4, air preheater 5, bag filter 6
And the combustion gas is discharged to the outside as shown at 22. Since the fly ash contains a large amount of unburned components, it is burned again in the combustion furnace to improve the thermal efficiency of the device. That is, since most of the fly ash (about 70 to 90%) is collected by the multi-cyclone 3, the ash collected here and the ash collected by the economizer 15 are collected in the ash tank 7. The
A proper amount is taken out from the ash dischargers 17 and 17 ', and the air from the blowers 8 and 8'through the ejectors 13 and 13', the ash flow pipes 9 and 9'for in-layer injection, and the main combustion fluidized bed furnace 1 and unburned air. It is blown into the fluidized beds 18, 18 'of the ash combustion furnace (Carbon burn up Cell (CBC)) 2 through the ash nozzles 10, 10'. The combustion ash collected by the denitration device 4, the air preheater 5, and the bag filter 6 is carried to a silo by the ash conveyor 12 and used as a cement raw material or other purposes.

[Problems to be solved by the invention]

In the above-mentioned conventional technology, when the air chamber of the fluidized bed of MBC, CBC is made into a multi-chamber type (multi-cell) and the number of cells to be operated is increased or decreased according to the size of the load, the ash nozzle to the idle cell or the ash flow pipe An accident occurs in which the fluid medium in the fluidized bed flows backward and is blocked. The same applies when the blower stops due to a trip accident. This is because the pressure of the fluidized bed part blown by the ash nozzle is about 1000 ~
This is because the pressure is 1500 mm of water and the pressure is high, and when the air pressure in the ash flow pipe decreases, the flowing medium flows back into the ash nozzle. When the ash nozzle and the ash flow pipe are blocked in this way, there is a problem that unburned ash in the ash tank cannot be burned.

[Means for solving the problem]

The problems described above include a main combustion fluidized bed furnace and an unburned ash combustion fluidized bed furnace that burns unburned ash discharged from the fluidized bed furnace, and collects fly ash discharged from the main fuel fluidized bed furnace. In a fluidized bed combustion device having a collecting device and an ash tank for storing the collected fly ash, the fly ash of the ash tank is a fluidized medium bed of the main combustion fluidized bed furnace and the unburned ash burning fluidized bed furnace. The fluidized bed combustion apparatus is characterized in that an ash supply device for supplying the fly ash is provided to at least one of the empty columns while providing an ash supply device for supplying the ash to the inside.

〔Example〕

FIG. 1 shows an embodiment of the present invention. The same parts as those of the conventional technique described in FIG. This embodiment is different from the prior art in FIG. 2 in that MBC and C
The ash tank 7 is provided in case the ash flow pipes 9 and 9'and the ash nozzles 10 and 10 ', which are ash supply passages into the BC fluidized bed, are closed.
An ash tank overflow pipe 11 that connects the ash conveyor 12 and the ash conveyor 12 is provided.

When the ash nozzles 10 and 10 ', the ash flow pipes 9 and 9', etc. are closed, the valve 11a is opened and the ash in the ash tank 7 flows into the ash conveyor 12 through the ash tank overflow pipe 11. The fly ash supplied to the ash conveyor 12 is cut out by an ash ejector 20 provided below the ash conveyor, and through the ejector 21, by the air branched from the outlet air passage of the forced draft fan 14, for the upper layer blowing. After passing through the ash flow pipe 16, the empty tower section 19, 1 above the fluidized bed of MBC and CBC
It is blown into either or both of 9 '.

〔The invention's effect〕

According to the present invention, even if the ash supply path to the fluidized bed of the MBC and CBC is blocked, the fly ash is MBC or C through the ash tank overflow pipe, the ash conveyor, and the ash flow pipe for in-layer blowing.
It is possible to maintain the combustion efficiency of the equipment by supplying it to the empty tower section of BC and continuing the combustion of unburned ash.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a conventional technique. 1 ... Main combustion fluidized bed furnace, 2 ... Unburnt ash combustion fluidized bed furnace, 3
…… Multi cyclone, 4 …… Denitration device, 5 …… Air preheater, 6 …… Bag filter, 7 …… Ash tank, 8 …… Blower, 9,9 ′ …… Internal layer blowing ash flow tube, 10 , 10 '... Ash nozzle, 11 ... Ash tank overflow pipe, 12 ... Ash conveyor, 13 ... Ejector, 14 ... Push fan, 15 ... Economizer, 16 ... Layer-up ash flow Tube, 17 ... ash ejector, 18, 1
8 '... fluidized bed, 19, 19' ... empty tower section, 20 ... ash conveyor under ash ejector, 21 ... ash conveyor under ejector.

Claims (1)

(57) [Claims] 1. A main combustion fluidized bed furnace and an unburned ash combustion fluidized bed furnace that burns unburned ash discharged from the fluidized bed furnace, and collects fly ash discharged from the main fuel fluidized bed furnace. Device to
In a fluidized bed combustion device having an ash tank for storing collected fly ash, fly ash of the ash tank is supplied to the fluidized medium bed of the main combustion fluidized bed furnace and the unburned ash combustion fluidized bed furnace. A fluidized bed combustion apparatus comprising a supply device and an ash supply device for supplying the fly ash to at least one of the empty columns.