JPH07243631A - Fluidized bed type incinerator with drying part - Google Patents

Abstract

PURPOSE:To dispense with auxiliary fuel and economize in energy by burning sludge with a high content of water after drying it by utilizing the high-temperature gases from the combustion produced in a manner of self-combustion. CONSTITUTION:By operating a circulating blower 13 a layer filled with balls 9 on a perforated plate 3 inside a drying part 2 is fluidized. Next an air blower 26 is actuated so that a flow of air is passed from a hot-blast chamber 28 under an incinerating furnace 18, through a perforated plate 21, and through a sand-filled layer to make this layer into a fluidized bed 22. An igniting burner 23 is ignited and simultaneously with the heating of the fluidized sand layer 22 the hot blast produced is used to heat the inside of the incinerating furnace 18 and the rising hot blast is made to heat the fluidized layer filled with balls 9. When the temperature of the fluidized layer filled with balls 9 has reached a fixed point, a material with a high content of water is thrown in upon the fluidized layer filled with balls 9 from a material feeder 1. By vaporization though mixing and contact with the heated balls 9 the material releases the water contained therein and is dried also by the hot blast through the perforated plate 3. The dried material is thrown down upon the fluidized sand layer 22 successively, and ignited thereupon by the igniting burner 23 and burned continuously.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a fluidized incineration system having a drying part developed for efficiently burning a highly water-containing paste-like substance such as activated sludge or the like or a granular material having high cohesiveness due to water. It is about the furnace.

[0002]

2. Description of the Related Art It is difficult to incinerate a paste-like substance having a high water content such as activated sludge generated by wastewater treatment as it is. Even when burning in a furnace, a large amount of fuel is used for incineration.

[0003]

Prior art rotary kilns and fluidized incinerators are uneconomical because they require a large amount of fuel to burn high water content materials.

The present invention provides a device for maximally utilizing the heat capacity of activated sludge or the like to reduce the fuel required for combustion to zero or to a minimum.

[0005]

In order to achieve the above object, the present invention comprises a drying section in the upper part and a combustion furnace body in the lower part.

The drying section has a circular horizontal cross section, and the upper section has a cylindrical shape, the middle section has a conical shape, and the lower section has a cylindrical shape. A perforated plate is provided horizontally at approximately the middle of the lower cylindrical portion, a concentric cylinder of an upper cone is installed at the center thereof, and spheres (balls) are filled on the annular perforated plate.

A raw material feeder is arranged on the upper surface of the drying section, and a stirring mechanism including a rotating shaft, a stirring arm fixed horizontally to the rotating shaft, and a stirring rod is installed at the center of the upper surface.

Further, an opening is provided in the ball filling upper portion on the side surface of the lower cylindrical portion, an overflow pipe is attached, and a feeder is arranged in the opening pipe.
The outlet is open-connected to the side wall of the incinerator body.

An exhaust gas circulation pipe is attached to the upper side surface of the drying section and connected to a circulation blower. The outlet pipe of the circulation blower is divided into two parts, one is connected to the exhaust port through the exhaust damper, and one is connected to the outlet port provided on the side surface of the lower cylindrical portion of the drying section through the blow damper.

On the other hand, the incinerator body is composed of a cylinder (or a prism) in the upper part, a conical shape (or a pyramid shape) in the middle part, and a cylinder (or a prism) in the lower part.

A perforated plate is arranged horizontally in the middle of the lower cylindrical portion, and granules (sand) are filled to a certain height above the perforated plate. The lower part constitutes a hot air chamber.

An air preheating tube is arranged inside the side wall of the upper cylinder (or square tube) of the incinerator body, and its inlet side is connected to the air blower and its outlet side is connected to the hot air chamber.

An ignition burner is installed above the side surface of the lower cylindrical portion. Attach a discharge pipe to the upper side wall of the perforated plate,
Install an ash ejector on it.

[0014]

The operation of the fluidized incinerator constructed as described above will be described. The circulation blower is operated to blow air to fluidize the ball-packed layer on the perforated plate in the main body of the drying section. Next, an air blower is operated, and a perforated plate is passed through the hot air chamber in the lower part of the incinerator to ventilate the sand-filled bed to form a fluidized bed.

Next, the ignition burner is ignited, the sand fluidized bed is heated, and at the same time, the generated hot air rises while heating the inside of the incinerator to heat the fluidized ball fluidized bed.

The stirrer is driven to stir so that the fluidized bed of balls is heated uniformly. When the temperature of the ball fluidized bed reaches a certain temperature, a high water content raw material is charged into the ball fluidized bed from a raw material feeder. The raw material is mixed and brought into contact with the heated balls to evaporate the water content, and while being dried by the hot air blown from the perforated plate, the raw material moves while being stirred by the stirring rod in the annular fluidized bed.

The dried raw material overflows when it reaches the opening while moving, enters the feeder through the overflow pipe, and is dropped on the sand fluidized bed formed in the lower part of the incinerator body.

The dry raw material starts ignition and combustion on the fluidized bed by an ignition burner. Combustion continues because the dry raw materials are continuously dropped one after another. When the combustion of the raw material is started, the combustion of the ignition burner is stopped.

The high temperature combustion gas generated by the combustion of the raw materials rises in the furnace and heats the upper ball fluidized bed. At this time, since the combustion gas is at a high temperature as it is, there is a risk of damaging the structural materials such as the perforated plate for forming the fluidized bed. Part of the mixture is blown into the mixture and mixed with the combustion gas to obtain an appropriate gas temperature, and the mixture is blown into the ball fluidized bed.

As described above, the raw material having a high water content can be easily ignited after being dried and continuously burned.

[0021]

EXAMPLES Examples will be described with reference to the drawings.
FIG. 1 is a vertical cross-sectional explanatory view of a fluidized incinerator having a drying unit of the present invention. The present invention comprises a drying unit main body 2 composed of a cylinder and a conical weight, and an incinerator main body 18 composed of a cylinder (or a square cylinder) and a conical weight (or a pyramid).

The raw material feeder 1 is attached to the upper part of the drying section main body 2. The drying unit main body 2 has a cylindrical upper portion,
The central part is a conical shape with a downward restriction, and the lower part is a cylindrical shape.

A perforated plate horizontally at approximately the middle of the lower cylinder-1
(3) is attached, and the conical body 4 is arranged at the center thereof.
The stirring mechanism 5 is installed in the center of the upper surface of the drying unit, and the rotating shaft 6, the rotating arm 7, and a plurality of stirring bars 8 are vertically attached to the rotating arm 7. The upper surface of the porous plate-1 (3) is filled with spheres (balls) 9 at a constant height.

The circulation pipe 12 is attached to the side surface of the upper cylinder and is connected to the circulation blower 13. The outlet pipe of the circulation blower 13 is branched into two, one of which is provided on the lower side surface of the drying section through the blower damper 14. The remaining one is connected to the exhaust port 17, and the other one is connected to the exhaust port 17 through the exhaust damper 16.

An opening is provided on the side surface of the lower cylinder of the drying section main body 2 and the overflow pipe 10 is attached thereto. As shown in FIG. 2, the position of the opening is set at a position slightly deviated from the raw material dropping position so that the falling raw material does not directly overflow from the opening to the overflow pipe 10. A feeder 11 is connected to the overflow pipe 10, and an outlet of the feeder 11 is connected to an opening on a side surface of an upper cylinder (or a square cylinder) of the incinerator body 18.

The upper part of the incinerator body 18 is a cylinder (or a prism), the middle part is a cone (or a cone) of the lower diaphragm, and the bottom is a cylinder (or a prism). Incinerator body 18
The outer surface of the is covered with a steel shell and the inner surface is lined with a refractory material 19.
A combustion space 20 is formed by the upper cylinder and the middle cone.

A perforated plate-2 (21) approximately in the middle of the lower cylinder
Is installed horizontally (or with a slight inclination toward the discharge pipe 24), and the upper part thereof is filled with sand to form a fluidized bed (sand) 22. The lower part is a hot air chamber 28.

The air blower 26 communicates with the inlet of the air preheating pipe 27 installed on the upper side surface of the incinerator body 18. The outlet of the air preheating pipe 27 communicates with the hot air chamber 28 by piping. Further, an opening is provided on the side surface of the fluidized bed 22, and the discharge pipe 24
And the ash ejector 25 is attached to the lower end. Further, an ignition burner 23 is installed on the side surface of the lower cylinder at the height of the fluidized bed.

Since the present invention is constructed as described above, it exhibits the effects as described below.

Feeder 11, stirring mechanism 5, circulation blower 1
3. The air blower 26 operates in this order. Then, the ignition burner 23 is ignited. The sand and the blown air of the sand fluidized bed 22 fluidized by the blowing of the air blower 26 are simultaneously heated by the ignition burner 23.

Heating. The heated air rises through the combustion space 20 and passes between the perforated plate-1 (3) and the filled balls 9. At this time, the ball 9 is heated. The air whose temperature has been lowered by heating is sucked by the circulation blower 13 through the circulation pipe 12, is emitted to the atmosphere from the exhaust port 17 via the exhaust damper 16.

When the temperature controller 33 at the inlet of the drying section reaches a predetermined temperature (for example, 250 ° C.), the raw material feeder 1 is operated to fill the balls 9 of the drying section 2 with the raw material (eg, 70 to 80% moisture). Pour into layers. The ball 9 heated to 250 ° C. and the raw material are stirred, mixed and contacted by the stirring rod 8 in the annular packed bed, and the raw material is heated and dried. The hot air that has passed through the porous plate-1 (3) also dries the raw material.

The raw material (eg, water content of 10% or less) heated and dried in the ball-packed bed moves in the ring-shaped packed bed with the rotation of the stirring rod 8 and reaches the overflow pipe 10 through this opening. It overflows into the pipe and is supplied into the incinerator body 18 through the feeder 11.

The dry raw material fed into the incinerator main body 18 drops onto the heated sand fluidized bed, where it is further heated. Dispersed. The air for burning the dry raw material is heated by the air blower 26 through the air preheating pipe 27, and the dry raw material is immediately ignited by the burner 23 for ignition. Start burning.

The high temperature combustion gas generated by the combustion of the raw material rises in the combustion space 20. This combustion gas is 80
Since it reaches a high temperature of 0 to 1000 ° C, the perforated plate-
1 (3), passing through the filled balls 9 may cause burnout and partial combustion of the raw material. Therefore, a part of the exhaust gas, which has been used for drying and has a low temperature, is passed through the blower damper 14 by the circulation pipe 12 and the circulation blower 13, and then the perforated plate-
It is blown into the lower space of 1 (3), mixed with high temperature combustion gas, and cooled to a temperature suitable for drying.

The combustion gas cooled to an appropriate temperature passes through the perforated plate-1 (3) and the ball packed bed to dry the raw material to further lower the gas temperature, and the circulation pipe 12, the circulation blower 13, the exhaust damper. The gas is discharged from the exhaust port 17 to the atmosphere via 16.

On the other hand, the sand fluidized bed 22 is heated to a high temperature by the combustion of the dry raw material, and the air preheated to about 300 ° C. by the air preheating pipe 27 is blown into the fluidized bed 22 by the generation of the high temperature combustion gas. The dry raw material put into the sand fluidized bed 22 in such a state continuously continues to burn. The ignition burner 23 extinguishes the fire.

The in-furnace pressure controller 31 keeps the in-furnace pressure at almost the same pressure as the atmospheric pressure and stabilizes combustion in the incinerator.
The exhaust damper 16 is interlocked and adjusted by the drive motor 29.

The temperature controller 32 at the inlet of the drying section detects the temperature at the inlet of the drying section so that the high temperature combustion gas does not directly enter the drying section, and works in conjunction with the blow-in damper 14 so that the temperature becomes an appropriate temperature, so that the low temperature exhaust gas is discharged. Operates to blow.

The present invention uses sludge having a high water content as described above,
It is a system that burns high-temperature combustion gas generated by self-combustion in an efficient manner and then burns it. Normally, it is a very energy-saving incinerator that can burn without auxiliary fuel.

[0040]

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional explanatory view of a fluidized bed incinerator having a drying unit.

FIG. FIG.

FIG. 3 is a control system diagram of a fluidized incinerator.

[Explanation of symbols]

1. Raw material feeder 17. Exhaust port 2. Drying unit body 18. Incinerator body 3. Perforated plate-1 19. Refractory material 4. Conical body 20. Combustion space 5. Stirring mechanism 21. Perforated plate-2 6. Rotating shaft 22. Fluidized bed (sand) 7. Rotating arm 23. Ignition burner 8. Stir bar 24. Discharge pipe 9. Sphere (ball) 25. Ash ejector 10. Overflow pipe 26. Air blower 11. Feeder 27. Air preheating tube 12. Circulation pipe 28. Hot air chamber 13. Circulation blower 29. Drive motor 14. Blowing damper 30. Pressure measurement port 15. Outlet 31. Furnace pressure regulator 16. Exhaust damper 32. Drying part inlet temperature controller

Claims (4)

[Claims] 1. A drying section body (2) comprising a drying section body (2) consisting of a cylinder and a cone and an incinerator body (18) consisting of a cylinder (or square tube) and a cone (or pyramid).
, The raw material feeder (1) is attached to the upper part, the perforated plate-1 (3) is horizontally attached to the middle of the lower cylindrical part, and the conical body (4) is vertically arranged in the central part of the lower cylindrical part. The stirring mechanism (5) is installed in the above, the rotating shaft (6), the rotating arm (7), and the stirring rod (8) are attached thereto, and the side wall of the lower cylindrical portion, the perforated plate-
1 (3) is provided with an opening in the upper part of the overflow pipe (10) feeder (1
1) is connected and the feeder outlet pipe is connected to the opening in the middle side wall of the incinerator body (18). A circulation pipe (12) is attached to the upper side wall of the drying unit main body (2) to connect with the circulation blower (13), the outlet pipe of the circulation blower (13) is branched into two, and one is through a blow damper (14). , Connected to the air outlet (15) at the bottom of the drying section, and the other is an exhaust damper (16)
To the exhaust port (17). Perforated plate-1 (3)
The top is filled with balls (9). The upper cylinder of the incinerator body (18) is connected to the cylinder at the bottom of the drying furnace, the perforated plate-2 (21) is placed horizontally in the center of the lower cylinder of the furnace body, and sand is filled on top of it. Then, a hot air chamber (28) was formed under the perforated plate-2 (21), connected to a pipe from an air blower, and an ignition burner (23) was arranged on the upper side wall of the perforated plate-2 (21). Fluidized incinerator with drying section. 2. The feature that the outlet pipe of the air blower (26) is connected to an air preheating pipe (27) arranged on the side wall of the incinerator body (18), and the outlet pipe is connected to the hot air chamber (28). A fluidized incinerator having a drying unit according to claim 1. 3. A fluidized incinerator having a drying part according to claim 1, wherein the pressure measuring port (30), the furnace pressure regulator (31) and the exhaust damper (16) are linked together. 4. A fluidized-bed drying oven having a drying part according to claim 1, wherein a temperature controller (32) is attached to a side wall of a lower cylinder of the drying part so as to interlock with a blowing damper (14). .