JP2621404B2 - Aeration tube structure of fluidized bed incinerator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a diffuser tube structure for a fluidized bed incinerator.

[Prior Art] A fluidized bed incinerator is known which burns an incineration object while forming a fluidized bed with an incineration object such as refuse or sludge cake and a fluidized medium by fluidizing air blown from an air diffuser. I have.

 The fluidized bed incinerator will be described with reference to FIG.

In FIG. 6, reference numeral 1 denotes a fluidized bed incinerator, 2 denotes a plurality of diffuser tubes traversed across the incinerator 1 at a distance from each other, and 3 denotes a diffuser tube formed above the diffuser tube 2. The fluidized bed 4 in the incinerator 1 is a packed bed formed in the incinerator 1 below the diffuser 2. A plurality of air diffusers 2a are formed on both side walls of the air diffuser 2 along the longitudinal direction one by one.

After crushing the incinerated materials such as garbage and sludge case,
Is supplied from above the side wall into the incinerator 1 by the incinerator 1
The fluidized bed blown from the jet port 2a of the diffuser 2 forms a fluidized bed 3 together with a fluidized medium made of sand. Then, the incineration material is subjected to primary combustion while forming the fluidized bed 3 and then secondary-combustion in the freeboard space 6 in the incinerator 1 above the fluidized bed 3 to complete incineration.

The packed bed 4 is composed of a bed of a fluid medium filled in the lower part of the incinerator 1 below the diffuser 2. The fluidized medium is discharged from the packed bed 4 by the discharge device 7 provided at the lower part of the incinerator 1 in order to remove the incombustibles in the incinerator from the incinerator 1. As a result, the incombustibles in the incineration material fall into the packed bed 4 through the gap between the diffuser tubes 2 and are then discharged from the lower part of the incinerator 1 through the packed bed 4 together with the fluidized medium. The discharged incombustibles are separated from the fluid medium, the fluid medium is resupplied into the incinerator 1 from above the side wall, and the incombustibles are separately treated.

[Problems to be Solved by the Invention] As described above, the fluid medium in the incinerator 1 is discharged from the lower part of the incinerator 1 and is replenished into the incinerator 1 from above. There is sand and pebbles brought in with the incineration material, and the amount of the fluid medium forming the fluidized bed 3 increases and decreases depending on the amount of the sand brought in as large as the fluid medium.

The amount of the fluid medium forming the fluidized bed 3 is determined together with the fluidized air blown into the fluidized bed 3 from the air diffuser 2 to determine the fluidized state of the fluidized bed 3. The fluidized state of the bed 3 is affected, and the combustion state of the incinerated material in the fluidized bed 3 cannot be maintained well.

That is, when the amount of the fluid medium forming the fluidized bed 3 increases, the thickness of the fluidized bed 3 increases. Therefore, when the amount of fluidized air is constant, the bubble diameter of the fluidized air grows in the fluidized bed 3. As a result, the fluidized bed 3 exhibits an intense fluidized state. At this time, since the effect of stirring and mixing of the incinerated material is enhanced, the combustion is generally performed violently, but the combustion becomes uneven in the cross-sectional direction of the fluidized bed 3. On the other hand, when the amount of fluidized air forming the fluidized bed 3 decreases and the amount of fluidized air is constant,
Is thin, fluidized air blows through the fluidized bed 3 and the fluidized bed 3 cannot be fluidized satisfactorily. For this reason, the burning of the incinerated material cannot catch up, and the incinerated material accumulates in the incinerator 1.

For this reason, conventionally, the fluid medium in the incinerator 1 is frequently discharged and replenished to eliminate fluctuations in the amount of the fluid medium forming the fluidized bed 3 and to appropriately adjust the fluidized state of the fluidized bed 3. Had been maintained.

SUMMARY OF THE INVENTION In view of the above situation, it is an object of the present invention to appropriately supply fluidized air (primary combustion air) in accordance with a change in the thickness of a fluidized bed and maintain a fluid state appropriately. It is an object of the present invention to provide a diffuser tube structure of a fluidized bed incinerator which enables the above.

Means for Solving the Problems According to the present invention, fluidized air is blown into a furnace in order to blow fluidized air into a fluidized bed of a fluidized medium and an object to be incinerated. In the diffuser tube structure of the incinerator, a multistage air outlet is formed in the diffuser tube in the height direction, and an opening and closing for selectively opening and closing the air outlets formed in the multistage in the height direction is performed. A valve is provided.

[Operation] The air diffuser is formed with air outlets in multiple stages in the height direction, and the air outlets formed in multiple stages in the height direction are provided with on-off valves for selectively opening and closing. By operating the valve, it is possible to selectively open an arbitrary air outlet formed in the diffuser tube to eject fluidized air. Therefore, even if the thickness of the fluidized bed formed above the diffuser tube changes by changing the air ejection port for ejecting the fluidized air along the height direction, the fluidized bed can be maintained as a constant fluidized bed thickness. The fluidized bed can be ejected, and the fluidized medium can be discharged and replenished to adjust the level or thickness of the fluidized bed and maintain the fluidized state of the fluidized bed appropriately.

EXAMPLES Examples of the present invention will be described in detail below.

FIG. 1 is a perspective view showing a first embodiment of an air diffuser to which the present invention is applied. As shown in FIG. 1, a diffuser tube 8 according to a first embodiment of the present invention has a plurality of air outlets 8a formed on both side walls of a tube having a circular cross section along a longitudinal direction, two steps vertically. An opening / closing valve 9 for selectively opening and closing these upper and lower two-stage air outlets 8a is provided in the air diffuser 8. The on-off valve 9 is formed of a cylinder having an outer diameter substantially equal to the inner diameter of the air diffuser tube 8 and opened at both ends, and the rotation center of the on-off valve 9 is used to rotate the on-off valve 9. A shaft 9a is provided. The on-off valve 9 is rotated by driving means (not shown) such as a motor engaged with the rotating shaft 9a. When the on-off valve 9 is rotated and positioned in the upper half of the diffuser 8, the air outlet 8 a in the lower stage of the diffuser 8 is opened, and fluidized air is selectively supplied from the air outlet 8 a in the lower stage. Squirts.
When the on-off valve 9 is rotated and positioned in the lower half of the air diffuser 8, the upper air outlet 8 a of the upper air diffuser 8 is opened and fluidized selectively from the upper air outlet 8 a. Air blows out.

Therefore, as shown in FIG. 2, when the amount of the fluid medium forming the fluidized bed 3 in the fluidized bed incinerator 1 increases,
By opening the air outlets 8a at the upper stage of all the plurality of diffuser tubes 8 and ejecting fluidized air therefrom, the amount of the fluid medium forming the fluidized bed 3 can be reduced by discharging the fluid medium. And can be reduced to an appropriate amount. Conversely, when the amount of the fluid medium forming the fluidized bed 3 decreases, the air outlets 8a at the lower stages of all of the plurality of diffuser tubes 8 are opened, and when the fluidized air is ejected therefrom, the fluidized fluid flows. The amount of flowing medium forming the layer 3 can be increased to an appropriate amount without replenishing the flowing medium. As a result, in any case, the fluidized state of the fluidized bed 3 can be appropriately maintained.

Also, as shown in FIG. 3, even when the amount of the fluid medium forming the fluidized bed 3 does not fluctuate, the upper and lower air outlets 8a of the plurality of diffuser tubes 8 can be selected and opened in various ways. Thereby, the flow state of the fluidized bed 3 can be variously controlled. Therefore, it is possible to appropriately perform combustion according to the quality of the incineration material.

FIG. 4 is a perspective view showing a diffuser according to a second embodiment of the present invention. As shown in FIG. 4, in the diffuser tube 10 of the second embodiment, in order to be able to largely change the jetting position of the fluidizing air in the vertical direction, two vertical steps are provided on both side walls of the tube having an oval cross section. The air outlets 10a are formed so as to be largely apart in the vertical direction, and the upper and lower air outlets 10a are selectively opened and closed, respectively, as shown in FIG. A simple on-off valve 9 is provided in the upper part and lower part in the air diffuser 10. In the state shown in FIG.
The air outlet 10a at the lower stage of the diffuser tube 10 is open, but when the upper and lower on-off valves 9 are respectively rotated half a turn, the air outlet 10a at the upper stage of the diffuser tube 10 is opened, and the air jet at the lower stage is opened. The outlet 10a is closed, so that the jetting position of the fluidizing air can be largely changed in the vertical direction.

In the above embodiment, the case where the air outlets are formed in both upper and lower sides on both side walls of the air diffuser is shown. However, as in the case of the air diffuser 11 of the third embodiment shown in FIG. The outlet 11a may be formed in three or more stages, and the on-off valve may be of a type that moves up and down in the air diffuser 11 like an on-off valve 12 having an H-shaped cross section shown in the figure. A diffuser tube of the third embodiment
According to 11, it is possible to determine the jetting position of the fluidizing air while selecting the jetting position in the vertical direction, and to finely control the jetting position in accordance with the change in the thickness or level of the fluidized bed.

[Effects of the Invention] According to the present invention, even if the amount of the fluid medium forming the fluidized bed changes and the layer thickness or the level of the fluidized bed changes, the fluid medium is not discharged or replenished without a constant amount. By supplying the fluidizing air, the fluidized state of the fluidized bed can be appropriately maintained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of an air diffuser to which the present invention is applied, FIG. 2 is an explanatory view showing an example of how fluidized air is ejected by the air diffuser of FIG. 1, and FIG. Is an explanatory view showing another example of how fluidized air is jetted out, FIG. 4 is a perspective view showing a second embodiment of an air diffuser to which the present invention is applied, and FIG. FIG. 6 is a schematic side view showing a fluidized bed incinerator. In the figure, 1 is a fluidized bed incinerator, 3 is a fluidized bed, 8, 10 and 11 are diffuser tubes, 8a, 10a and 11a are air jet ports, and 9 and 12 are on-off valves.

Claims (1)

(57) [Claims] 1. A diffuser tube structure of a fluidized bed incinerator which is stretched across a furnace in order to blow fluidized air into a fluidized bed of a fluid medium and an incineration object formed above the fluidized bed. Wherein the air diffuser is formed with multi-stage air jets in the height direction thereof, and provided with an on-off valve for selectively opening and closing the air jets formed in the multi-stages in the height direction. A diffuser tube structure for a fluidized bed incinerator.