JP2746318B2 - Fluidized bed combustion device for waste - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidized bed combustion apparatus for burning and incinerating waste such as waste plastic containing non-combustible materials such as iron scraps, which is separated from shredder dust and municipal waste. About.

[0002]

2. Description of the Related Art Conventionally, a fluidized bed incinerator as a fluidized bed incinerator which burns and incinerates waste such as waste plastics containing incombustibles such as iron scrap has a structure as shown in FIG.

[0003] Reference numeral 12 denotes a fluidized combustion chamber, in which an air dispersion pipe 11 composed of a plurality of horizontal pipes is mounted so as to cross the combustion chamber 12. A large number of air outlets 11a are formed at an obliquely lower position in the air dispersion pipe 11, and the air sent to the air dispersion pipe 11 via the pipe 15 by the air blower 13 is ejected from the air outlet 11a and flows. Medium 10
is fluidized to form a fluidized bed 10. The fluidized bed 10 is maintained at a predetermined high temperature.

[0004] Waste containing non-combustible materials such as iron chips is introduced into the fluidized bed 10 from above the fluidized combustion chamber 12 and fluidized and burned therein. Screw feeder 1 through discharge port 12a
6 is pulled out of the machine. Then, the incombustible material and the fluid medium are sent to the separator 17, where the incombustible material and the fluid medium are separated by the screen 17 a, and the incombustible material remaining on the screen 17 a is discharged out of the separator 17, and the screen 1 is removed.
The fluidized medium that has passed through 7a is returned to the fluidized combustion chamber 12 again by the circulation conveyor 18 and used. In the combustion of the waste containing the incombustible material, the incombustible material accumulates in the fluidized combustion chamber 12, so that the incombustible material must be removed from the fluidized combustion chamber 12.

The air dispersion pipes 11 for fluidizing the fluid medium in the fluidized combustion chamber are arranged at intervals in the horizontal direction, and the incombustible material and the fluid medium fill the gap between the dispersion pipes 11 together. It passes through the gap and falls down, but slender iron scraps such as wires and large-sized incombustibles do not pass through this gap and are gradually caught and accumulated. There is a problem that the fluid combustion of the material becomes impossible. This problem becomes remarkable when the interval between the dispersion tubes 11 is reduced. It is to be noted that there is a limit to widening the interval between the dispersion tubes 11 from the viewpoint of uniform fluidization.

FIG. 5 shows a case where the structure of the air distribution unit is an air distribution plate 20. In FIG.
Reference numeral 21 denotes a vertical air distribution pipe, and a cap 2 is provided at the upper end.
1a is fixed, and a plurality of air outlets 21b are formed below it at equal intervals in the circumferential direction. A large number of the air distribution pipes 21 formed in this manner have a horizontal partition plate 22.
Is fixed and arranged by. Each air distribution pipe 21
A water cooling tube 23 is provided between the two by a partition plate 22. Reference numeral 24 denotes a refractory attached above and below the partition plate 22. The upper surface 20a of the dispersion plate 20 (the upper surface of the refractory 24) is a horizontal plane. The outlets of the incombustibles and the fluid medium are opened in the furnace wall slightly above the air distribution plate 20, though not shown.

[0007] Such air is taken in from the air distribution plate 20 in the air chamber 25 of the arrangement to the air distribution pipe 21, the fluidized medium by being ejected from the air ejecting port 21 b to the fluidized combustion chamber 26 upward flow In the air dispersion pipe 21 of this structure, incombustible substances such as slender iron chips are caught between the adjacent caps 21a at the upper end of the dispersion pipe 21 by the air dispersion pipe 21 having this structure. Incombustibles are not easily discharged to the outside of the furnace easily, and the air dispersion pipe 11 having the horizontal structure is used.
There is a similar problem with the type.

[0008]

As described above, the problem to be solved is that when waste containing incombustibles is fluidly burned, the incombustibles cannot be discharged to the outside of the furnace smoothly. The point is that fluid combustion cannot be performed stably.

[0009]

According to the present invention, an upper end cap having at least an upper surface facing a fluidized combustion chamber is formed at the upper end of an air distribution tube with a planar upper surface, the upper surface being located on the side of an outlet for a fluid medium and incombustibles. And the upper end cap of the air distribution pipe adjacent to the outlet side is provided in a stepped manner such that the upper surface thereof gradually becomes lower as the upper side goes to the outlet side, and the air distribution pipe is provided. An air outlet is provided to open toward the outlet at a height between the lower surface of the upper end cap and the upper surface of the upper end cap of the air distribution pipe adjacent to the outlet.

The upper surface of the upper end caps of the air distribution tubes located in a row in a direction perpendicular to the direction toward the discharge port is provided at the same height, and the upper end caps of the air distribution tubes adjacent to the row are provided. The upper end cap is attached to the air distribution tube with a slight gap formed between it and the upper end cap, and the upper end cap of the air distribution tube adjacent to the outlet side is the upper end of the air distribution tube located at the outlet side. The end on the side opposite to the discharge port of the cap is inserted below the end on the discharge side of the upper end cap of the air distribution pipe located on the side opposite to the discharge port, and attached .
Sky ejected from the air distribution pipe in the part located on the discharge port side
Ejects air volume from the air dispersion pipe in the part located on the side opposite to the discharge port
It is characterized in that it is configured to be larger than the amount of air to be performed .

[0011]

In the configuration (1), in the fluidized combustion chamber, the fluidized medium is fluidized by the air jetted from the respective air distribution pipes to form a fluidized bed. An upper end cap having a flat upper surface facing the fluidized combustion chamber is provided on the air dispersion pipe so that the upper surface is inclined such that the discharge port side for the fluid medium and the incombustibles is lowered. The upper end cap of the air distribution pipe adjacent to the side is provided in a stepped manner so that the upper surface becomes lower in height as it goes to the discharge port side, and the air ejection port is provided on the air distribution pipe with the lower surface position of the upper end cap. Are opened toward the discharge port at a height between the air diffusion pipe and the upper surface of the upper end cap of the air distribution pipe adjacent to the discharge port. The discharged air flows along the upper surface of the upper end cap of the air distribution tube located on the discharge port side.

[0012] Thus, the fluid medium forming the fluidized bed flows toward the discharge port side along the stepped downward slope which is the upper surface of the upper end cap of the air distribution pipe adjacent to the discharge port side, and then rises. And perform a circulating operation of descending.
Thereby, a circulation operation is formed in the fluidized bed. In addition,
Air is supplied into the fluidized combustion chamber from the air outlets of the respective air distribution pipes by the action of an induction fan provided on the downstream side of the flue gas discharge port above the fluidized combustion chamber or a pushing fan provided on the upstream side of the air chamber. You.

Therefore, the waste put into the fluidized bed is efficiently mixed with the circulating fluid medium and is efficiently burned, and the incombustibles are discharged from the upper end of the air distribution pipe adjacent to the discharge port side. Along the stepped inclined upper surface of the cap, it flows smoothly from the high side on the side opposite to the discharge port side to the low side on the discharge port side, smoothly descends toward the discharge port without being caught by the upper end cap, etc., and partially flows The paper is discharged from the discharge port together with the medium. Thus, the fluidized bed is formed smoothly without obstruction of air ejection and fluidization is not hindered, and stable fluid combustion is performed.

A wide flat (planar) upper surface which is inclined so as to become lower toward the discharge port by the upper surface of the upper cap is formed in a stepped shape, and the upper cap of the air distribution tube located on the discharge port side. The end on the side opposite the discharge port of the air dispersion pipe enters the lower side of the end on the side of the discharge port of the upper end cap of the air distribution pipe located adjacent to the side opposite the discharge port, and there is no obstruction to the flow toward the discharge port. Therefore, the non-combustible material flows smoothly along the upper surface of the flat step from the high level on the side opposite the discharge port to the low level on the side of the discharge port without being caught, and is more reliably discharged to the discharge port. You.

Further, since a slight gap is provided between the adjacent upper end caps, even if the upper end caps are elongated by being heated by the high temperature fluidized bed, excessive stress is applied to the furnace body and the air dispersion pipe. It does not act and is a robust device, and the flatness of the upper surface of the flat upper end cap is effectively maintained.
In addition, it is ejected from the air distribution pipe in the part located on the outlet side.
Air distribution pipe in the part located on the side opposite the discharge port
The configuration was made larger than the amount of air blown out from
In the stepped upper surface of the upper end cap of many air distribution tubes
It flows along the descending slope toward the discharge port side,
The flow that forms a fluidized bed after rising and falling
Since the fluid circulation action of the moving medium is performed strongly,
The waste is smoothly and reliably discharged to the outlet, and the waste is
Mix well in the moving bed to increase the residence time,
The combustion ratio is increased.

[0016]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing one embodiment of a fluidized bed incinerator as a fluidized bed combustion apparatus according to the present invention, and FIG.
FIG. 3 is a plan view taken along line III of FIG. 2. The fluidized-bed incinerator 30 is defined by an air distribution plate 40 inside a furnace wall 31 formed of a refractory material 31a such as a castable, etc.
0 is formed with the air chambers 32 and 33 located at the lower part. The air distribution plate 40 is mounted to be inclined, and a number of air distribution tubes 41 are provided on the air distribution plate 40.
0 is vertically mounted.

As shown in FIG. 3, the air distribution pipe 41 is in a vertical direction in a plan view (a direction perpendicular to the direction toward the discharge port 50).
A plurality of rows (seven rows in this embodiment) are arranged at equal intervals in the horizontal direction (the direction toward the discharge port 50 side). So that the air distribution pipes 41 in a row are adjacent to each other in the horizontal direction.
Are arranged in a zigzag pattern so as to be staggered with the phase shifted in the vertical direction. That is, the dispersing tubes in the column adjacent in the horizontal direction are arranged at an intermediate position between the two dispersing tubes in the adjacent column. Each air distribution pipe 41 is fixed to a partition plate 46.

A water-cooling tube 45 is horizontally arranged and fixed between the air distribution tubes 41 so that the upper half of the water-cooling tube 45 is exposed to the partition plate 46. A castable (undefined refractory) is provided below the partition plate 46. And the like. Below the air distribution plate 40, there are positioned air chambers 32 and 33 divided into two chambers by a vertical partition wall 34. On the side of the air chamber 32, at the lowest position of the flowing combustion chamber 70, the flowing combustion chamber 70 is provided. A discharge port 50 is formed to communicate the fluid medium 61 and the incombustibles 63 such as iron chips to the outside of the furnace. Reference numeral 51 denotes an outlet end. The water cooling pipe 45 is also provided on the vertical wall of the discharge port 50 on the air chamber 32 side.
Is mounted so that a half of the cross section is exposed at the outlet 50. Reference numerals 36 and 37 are supply ports for supplying high-temperature air to the air chambers 32 and 33, respectively.

As shown in FIGS. 1 and 2, the air distribution pipe 41 is formed so as to be shortest at the discharge port 50 side and to be gradually longer toward the side opposite to the discharge port side so as to protrude upward from the air distribution plate 40. It is provided. A flat upper end cap 42 is attached to the upper end of each of the air distribution pipes 41 so as to be inclined so as to become lower toward the discharge port 50 side. The upper end cap 42 of the tube 41 is attached stepwise so that the upper surface 42a gradually becomes lower as it goes toward the outlet 50 side.

The upper end cap 42 acts so that the fluid medium 61 does not enter the air ejection port 43 of the air dispersion pipe 41, and extends from the upper end position of the air dispersion pipe 41 to the side opposite to the discharge port so that the end 42b is adjacent. Air dispersion pipe 41 on the side opposite to the discharge port
The lower end of the upper end cap 42 is inserted under the end on the discharge port side up to the center position of the air distribution pipe 41, and both ends of the end 42b are abutted and fixed to the air distribution pipe 41. The upper surface 4 of the upper end cap 42 of the air distribution pipe 41 located in a column in a direction orthogonal to the direction toward the discharge port 50 side.
2a have the same height, and a small gap 80 of, for example, about 2 to 3 mm is provided between the ends of the upper end caps 42 of the air distribution pipes 41 adjacent in the row. In the figure, the upper surface 42a of the upper end cap 42 is formed by inclining a plane of the same height which is wide in the vertical direction.

Each of the air distribution pipes 41 has an air ejection port 43.
Is provided toward the discharge port 50 at a height position between the lower surface position of the upper end cap 42 and the upper surface 42a of the upper end cap 42 of the air distribution pipe 41 adjacent to the discharge port 50 side. As shown in FIG. 3, the air outlets 43 are distributed at an equal angle with respect to the center line of the air dispersion pipe 41 in the direction of the outlet 50 side (lateral direction), and the outlets 50 have an entire angle α.
The angle α is set to a wide angle such as 120 degrees so as to hit the fluid medium 61 and the non-combustibles 63 in front of the air ejection port 43, for example, 120 degrees.

The air that has flowed out of the air outlet 43 (indicated by the symbol O in the figure) just flows toward the outlet 50 along the upper surface 42a of the upper end cap 42 that is adjacent to the outlet 50 and that is adjacent in the vertical column. It is gushing and flowing. Waste is introduced into the fluidized bed 60 from above at the position indicated by the symbol R in FIG. 70a is a free board above the fluidized bed 60. Sand or limestone such as silica sand having a particle size of about 0.5 to 1.0 mm is used as the fluid medium.

Next, the operation of the fluidized bed incinerator having such a configuration will be described. The high-temperature air introduced into the air chambers 32 and 33 is supplied to respective air distribution tubes 41 attached to the air distribution plate 40.
Into the fluidized combustion chamber 70 from the air outlet 43 at the upper portion thereof, and the upper end cap 42 of the air distribution pipe 41.
The fluidized medium 61 is fluidized on the upper surface 42a of the
Is formed. The fluidized bed 60 is maintained at a predetermined high temperature, for example, 800 to 900 ° C.

In this case, the upper surface 42a of the upper end cap 42 of the air distribution pipe 41 is sequentially lowered from the discharge port side to the discharge port 50 side, and the air ejection port 43 of the air distribution pipe 41 is discharged. Air is sequentially opened at lower positions toward the outlet 50 side, and air flows toward the outlet 50 side along the upper surface 42a of the upper end cap 42 (reference numeral O in FIG. 1).
1), a fluidized medium 61 is provided in the fluidized bed 60 as indicated by the symbol Q in FIG.
From the air outlet 43 to the outlet 50 along the downward slope of the upper surface 42a of the upper end cap 42 of the air distribution pipe 41 on the outlet 50 side, and then rises and descends. Mixing of induced and flowing medium 61,
Stirring is performed to induce a stirring action of the fluidized bed 60.

From the fluidized combustion chamber 70, air is sucked and discharged from the free board 70a by an induction fan. In some cases, a pushing fan may be provided upstream of the air chamber instead of the induction fan to supply air into the fluidized combustion chamber 70. The upper end cap 4 is provided on the upper surface of the air distribution plate 40.
The sand as the fluid medium 61 falls from the second gap 80 and is deposited and acts as a heat insulating layer.

The waste 64 containing the incombustibles 63 is introduced into the fluidized bed 60 thus formed from above the fluid discharge chamber 70 at the position indicated by the symbol R in FIG. Then, the waste 64 is uniformly agitated in the fluidized bed 60 in which the fluid medium circulates and flows toward the discharge port 50 side as indicated by reference numeral Q, and is efficiently burned. . The combustion exhaust gas is exhausted outside the fluidized combustion chamber 70 through the free board 70a. As shown in FIG. 1, incombustibles 63 such as wires and iron scraps are disposed in the fluidized bed 60 from the inclined upper surface 42 a of the upper end cap 42 of the air dispersion pipe 41 on the upper side on the opposite side to the outlet 50. It descends smoothly along the inclined upper surface 42a of the upper end cap 42 of the lower-side air distribution pipe 41 in order.

That is, the upper surface 42a of the upper end cap 42 of the air distribution tube 41 is set so as to be gradually lower toward the discharge port 50 side, and the air distribution tubes in a row in a direction orthogonal to the direction of the discharge port 50 side. Upper surface 42 of upper end cap 42 of 41
a is inclined at the same height, is made the same plane, is formed in a stepped shape, and the air ejection port 43 of the air distribution pipe 41 is formed.
Is opened at a wide angle α toward the discharge port 50, and air flows toward the discharge port 50 along the upper surface 42a of the upper end cap 42 of the air distribution pipe 41 located on the adjacent discharge port 50 side. Further, the upper end cap 42 extends from the upper end position of the air distribution pipe 41 to the side opposite to the discharge port, and the end 42b is the end of the upper end cap 42 of the air distribution pipe 41 adjacent to the side opposite to the discharge port on the side of the discharge port 50. And there is no factor obstructing the flow to the discharge port 50 side.

As a result, the incombustibles 63 are prevented from being caught on the upper end cap 42, and the inclined upper end 42a of the upper end cap 42 of the air distribution pipe 41 is inclined.
Flows smoothly from a high level on the side opposite to the discharge port to a low level on the side of the discharge port 50, and reaches the lowest level, and reaches a part of the fluid medium 6
1 and is discharged to the discharge port 50 from the discharge port end 51 to the outside of the machine.

A gap 80 is formed between the upper end caps 42 of the adjacent air distribution tubes 41 in a column in a direction perpendicular to the direction toward the discharge port, so that the fluidized bed 60 has a width of 800 to 900. Even if it is heated by a high temperature of ℃, elongation is allowed, and the air dispersion pipe 41 and the furnace body are made rigid without applying excessive force due to thermal stress, and the upper surface 42a of the upper end cap 42 is also uniform. A flat surface is secured.

In the present embodiment, the amount of air supplied to the air chamber 32 is made larger than the amount of air supplied to the air chamber 33. Therefore, the gas distribution plate 4 facing the air chamber 32
0 is supplied to the air distribution pipe 41 of the air chamber 3.
The amount of air supplied to the air dispersion pipe 41 of the gas dispersion plate 40 facing 3 is larger than the amount of air supplied. Therefore, the outlet 5
Due to the large amount of air jetted from the air distribution pipe 41 of the air distribution plate 40 at the portion closer to the zero side, the outlet 5 of the air distribution plate 40 of the entire fluidized bed 60 in the direction indicated by the symbol Q in FIG.
The fluid circulation action from the 0 side to the non-discharge port side is performed more strongly, and the incombustibles 63 are more smoothly and reliably discharged, and the waste 64 is discharged from the R position of the upper surface of the fluidized bed 60 on the non-discharge port side. , The waste 64 is mixed well with the fluidized bed 60, the residence time is increased, and the combustion ratio (efficiency) in the fluidized bed 60 is increased.

The incombustible material 63 and the fluid medium 61 discharged from the furnace through the discharge port 50 through the discharge port end 51 are sent to a separator (not shown), and the screen is used to screen the noncombustible material 6.
The incombustible material 63 separated on the screen and separated into the fluid medium 61 is discharged to the outside of the separator and collected, and the fluid medium 61 passing through the screen is again regenerated by a suitable transport means such as a circulating conveyor. Is returned to the fluidized bed 60 for circulation.

In the above embodiment, the upper end cap 42 is a flat upper end cap. However, if the upper end cap is formed at least in a flat shape and is inclined toward the discharge port side, the upper end cap 42 becomes a flat upper shape. There is no limit. Also, an example in which the upper end cap 42 is attached to each of the air distribution pipes 41 has been described.
The upper end cap 42 may be configured such that a plurality of tubes, for example, two tubes are set as a block group, and one plate is attached to the block group.

The heights of the upper surfaces 42a of the upper end caps 42 of the air distribution tubes 41 in the direction perpendicular to the direction toward the discharge port 50 side are the same, but are not necessarily limited thereto. It may be the height of. Although the air distribution plate 40 is attached at an angle, it goes without saying that the air distribution plate 40 may be attached horizontally.

[0034]

As is apparent from the above description, the fluidized bed combustion apparatus for waste according to the present invention discharges incombustibles contained in waste very smoothly and reliably to the discharge port. br /> can be discharged to the outside, therefore, stable fluidized bed without fluidizing the fluidized medium is prevented is formed, it can be performed reliably and stably flow combustion waste. It can also increase the waste combustion rate
You. Also, the high temperature of the fluidized bed causes the upper end cap to expand thermally.
However, if this is acceptable and the device is robust against heat,
The top surface of the upper end cap is also kept flat and even
To maintain the smooth flow of incombustibles
Can be.

[0035]

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a fluidized bed incinerator of the present invention.

FIG. 2 is an enlarged view of a main part of the air distribution pipe section of FIG.

FIG. 3 is a plan view taken along line III in FIG. 20;

FIG. 4 is a longitudinal sectional view showing a schematic configuration of a conventional fluidized bed incinerator.

FIG. 5 is a longitudinal sectional view showing another example of the conventional air distribution plate.

[Explanation of symbols]

 Reference Signs List 30 fluidized bed incinerator 40 air dispersion plate 41 air dispersion tube 42 upper end cap 42a upper end cap upper surface 42b opposite end of upper end cap on the side opposite to outlet 43 air outlet 50 outlet 60 fluidized bed 61 fluidized medium 63 incombustibles 64 waste 70 Fluid combustion chamber 80 Gap between top caps

Claims (1)

(57) [Claims] 1. A fluidized bed is formed by injecting air from a number of air dispersion tubes into a fluidized combustion chamber to burn waste in the fluidized bed and to discharge a fluidized medium and incombustibles from an outlet through an outlet. After removing incombustibles outside the extracting machine, in the fluidized bed combustion device for waste in which the fluidized medium is returned to the fluidized combustion chamber again, at least the upper surface facing the fluidized combustion chamber is flat at the upper end of the air dispersion pipe. The upper end cap is formed so as to be inclined so that the upper surface thereof becomes lower toward the outlet side, and the upper end cap of the air distribution pipe adjacent to the outlet side is sequentially arranged as the upper surface goes to the outlet side. The air outlet is provided in a stepwise manner so as to have a low height, and the air ejection port is provided in the air distribution tube at the height between the lower surface position of the upper end cap and the upper surface of the upper end cap of the air distribution tube adjacent to the outlet side. And open it toward At right angles to the direction toward the outlet.
Upper surface of the top cap of the air distribution tube located in the row
Are provided at the same height, and the top cap is
Small gap between the upper end cap of the adjacent air distribution pipe
Leave a gap to form the same plane and attach it to the air distribution pipe.
The upper end cap of the air distribution pipe adjacent to the outlet side
Is the discharge end of the upper end cap of the air distribution pipe located on the discharge port side.
The upper end of the air distribution tube whose outlet end is located on the opposite side to the outlet
Enter below the discharge end of the cap and install
From the air distribution tube in the portion located on the outlet side.
The amount of air to be discharged from the air distribution pipe in the part
A fluidized bed combustion device for waste, characterized in that the amount is larger than the amount of air jetted from the device.