JPS6363804B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a fluidized bed combustion apparatus in which a partition wall is attached to the cavity of the combustion chamber, the gas discharge passage is lengthened, and the fluidized medium scattered together with the combustion gas from the fluidized bed is removed from the cavity of the combustion chamber. The present invention relates to a fluidized medium scattering prevention device for a fluidized bed combustion apparatus, in which the fluidized medium is collected and returned to the fluidized bed so that it can be reused.

Fluidized bed combustion equipment fluidizes a fluidized medium made of inert granular material such as sand in a combustion chamber by blowing air from the bottom of the furnace, creating a state in which the fluid moves actively as if it were boiling. A device that forms a fluidized bed and supplies a combustion substance such as coal into the fluidized bed area for combustion, and the generated heat can be exchanged and recovered by heat exchanger tubes disposed within the fluidized bed area. When water is passed through the heat transfer tube, it becomes a fluidized bed boiler.

The fluidizing air injected into the fluidized bed takes on the shape of bubbles within the fluidized bed, expands as it rises within the fluidized bed, and bursts when it reaches the fluidized bed interface. The fluidized medium particles at the interface of the fluidized bed are repelled by this bursting energy and scattered to a relatively high position, and some of them are scattered outside the combustion chamber along with the combustion gas. The lower the height of the furnace body, that is, the height (H ₁ ) of the cavity of the combustion chamber, as shown in FIG. 1, the more easily this fluidized medium will scatter together with the combustion gas. In a fluidized bed combustion device, it is necessary to keep the fluidized bed height (h) constant, so as shown in Figure 2, the height of the combustion chamber (H ₂ ) is set high enough to prevent the fluidized medium from scattering due to the bursting energy. Otherwise, the amount of flow medium that has flown out must be replenished.

For this reason, it is necessary to take measures to prevent the scattering of fluidized media in fluidized bed combustion apparatuses where the height of the furnace is limited, such as marine fluidized bed boilers and fluidized bed package boilers.

Therefore, an object of the present invention is to keep the furnace height low by taking measures to prevent the fluidized medium from scattering.

An embodiment of the present invention will be explained with reference to the figures. 1 is a combustion chamber of a fluidized bed boiler, and 2 is a fluidized bed. Reference numeral 3 denotes an empty tower portion of the combustion chamber, and 4 a wind box configured to supply fluidizing air from the bottom of the fluidized bed 2 to float the fluidized medium in the fluidized bed. The bubbles 5 are small at the bottom of the fluidized bed 2, but grow larger as they rise in the fluidized bed, as shown in Figures 1 and 2, and the bubbles 5 burst at the interface of the fluidized bed, scattering the fluidized medium particles. . FIG. 3 shows a fluidized bed combustion apparatus to which the present invention is applied, which has a lower end below an exhaust gas outlet 7 provided in the surrounding wall above the fluidized bed interface 6, and is inclined upward in the hollow column 3. The inclined plate 8 is provided with a gap 11 between the lower end of the inclined plate 8 and the side wall.
A partition plate 9 having an opening vertically upward from the ceiling to the ceiling is provided, and a partition plate 10 hanging vertically from the ceiling of the tower section 3 and having an opening between the inclined plate 8 and the exhaust gas outlet is provided. 7, an exhaust gas passage is formed above the empty tower section 3. 12 is a heat exchanger tube arranged within the fluidized bed 2. FIG. 4 shows another embodiment of the present invention, in which a plurality of partition plates 9 and 10 are provided, and the inclined plate 8 is deformed into a valley shape. That is, as can be seen in FIG. 5, which shows the cross section taken along line A-A in FIG. The partition plate 9' is bent into a dogleg shape in cross section.
Further, as can be seen in FIG. 5, which is a view taken along the line B--B in FIG. 4, the lower end of the partition plate 10 is shaped to protrude in accordance with the valley shape of the inclined plate 8.

Next, to explain the operation of the present invention, fluidizing air is sent into the fluidized bed 2 from the wind box 4, fluidizes the fluidized medium, becomes gas bubbles 5, rises in the fluidized bed 2, and reaches the fluidized bed interface 6. Burst. The fluidized medium particles are repelled by this bursting energy, rise together with the exhaust gas, and are discharged from the exhaust gas outlet 7, but the passage is blocked by the inclined plate 8 and partition plate 9 in the cavity 3 of the combustion chamber. The inclined plate 8
The fluidized medium and combustion ash mixed with the exhaust gas on the lower surface are partially separated and fall into the fluidized bed 2. On the other hand, the exhaust gas passes through a passage formed by alternating partition plates 9 and 10, during which time the exhaust gas moves up and down, and the exhaust gas and fluidized medium are further separated, and the exhaust gas is discharged from the exhaust gas outlet 7. It is discharged.
Partition plates 9, 10 or partition plates 9, 10, 9', 1
The flowing medium separated by 0' falls onto the inclined plate 8. The fluidized medium that has fallen onto the inclined plate 8 descends along the inclination, and is finally returned to the fluidized bed 2 through the gap 11.

As described above, the present invention provides a fluidized bed combustion apparatus in which a sloped plate having a lower end below the exhaust gas outlet in the cavity of the combustion chamber and slopes into the cavity, and an opening extending upward from the sloped plate to the ceiling. The exhaust gas passage is formed by alternately arranging partition plates that have an opening, and partition plates that hang down from the ceiling of the tower section and have an opening between them up to the inclined plate, and also form an exhaust gas passage between the lower end of the inclined plate and the side wall of the combustion chamber. Since a gap is provided between the two, the fluidized medium scattered on the fluidized bed interface is returned to the fluidized bed by the action of the inclined plate without being discharged from the exhaust gas duct, thereby greatly preventing consumption of the fluidized medium. It is something that can be done. Therefore, the frequency of replenishment of inert granular materials such as sand can be significantly reduced, which not only improves various boiler characteristics but also reduces the height (H ₁ ) of the fluidized bed boiler.
It can be kept low, so it can be used not only on land, but also on land.
It is extremely effective especially as a ship boiler.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are two examples showing cross sections of conventional fluidized bed boilers to explain the present invention, FIG. 3 is a cross sectional view of a fluidized bed boiler showing an embodiment of the present invention, and FIG. 4 is another example. FIG. 5 is a sectional view taken along the line AA in FIG. 4, and FIG. 6 is a sectional view taken along the line BB in FIG. 4. 1...Fluidized bed boiler combustion chamber, 2...Fluidized bed, 3
... Combustion chamber empty tower section, 4 ... Wind box, 5 ... Air bubbles, 6
... Fluidized bed interface, 7 ... Exhaust gas outlet, 8 ... Inclined plate, 9, 9' ... Partition plate, 10, 10' ... Partition plate, 11 ... Gap, 12 ... Heat exchanger tube.

Claims (1)

[Claims] 1. In a fluidized bed combustion device that discharges exhaust gas from the side wall of the upper part of the cavity in the combustion chamber, an inclined plate having a lower end below the exhaust gas outlet provided in the side wall and sloping upward into the cavity, and the inclined plate a partition plate disposed vertically upward from the ceiling and having an opening between it and the sky tower ceiling;
Exhaust gas passages are formed by alternately arranging partition plates that hang down from the ceiling of the tower section and have openings between them up to the inclined plate, and a gap is provided between the lower end of the inclined plate and the side wall of the combustion chamber. A fluidized bed combustion apparatus characterized by: