JP3347262B2 - Fluid bed incinerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fluidized bed incineration
The present invention relates to a fluidized bed incinerator which controls the furnace based on the amount of waste (garbage) charged to the incinerator.

[0002]

2. Description of the Related Art A fluidized bed incinerator will be described with reference to FIG.
3. A secondary combustion chamber 2 is formed above the flow chamber 3, and the waste a charged into the main body 1 of the incinerator from the duster 17 via the chute 19 is discharged into the primary air in the flow chamber 3. b. incineration with the formation of a fluidized bed, and the unburned gas
In the secondary combustion chamber 2, complete combustion is performed by the secondary air c (see an embodiment described later).

[0003] The general combustion control of this fluidized bed incinerator is to measure the oxygen concentration and temperature of the exhaust gas,
Controls the amount of secondary air sent into the chamber (feedback control)
And other methods have been used. However, the oxygen concentration and the temperature can be measured after the waste a has been burned, the response is poor, and the temporary incomplete combustion in the secondary combustion chamber 2 cannot be avoided. For this reason, so-called feedforward control has been performed in which the amount of waste a into the incinerator main body 1 is predicted to control the combustion conditions. As an example of the feedforward control, there is a technique described in Japanese Patent Laid-Open No. 4-273911 shown in FIG.

In this technique, in FIG. 4, an input pipe (chute) 72 for waste a is connected to a side wall of an incinerator 71, and a disperser 73 is disposed at a connection portion. A rotary drum (air seal device) 74 and a seal plate 75 for pressing the rotary drum (air seal device) are arranged in the waste a charging pipe 72 upstream of the disperser 73. The rotating drum 74 has flanges 74b at both ends of a body 74a, and a partition plate 79 is provided between the flanges 74b at equal intervals in the circumferential direction to form pocket portions 77. The rotating drum 74 is rotated by a motor M as shown by an arrow. And waste a
Into each pocket 77 and send it out.

The seal plate 75 is swingable via a shaft 78 and is pressed against a rotating drum 74. The inclination angle of the seal plate 75 is constantly monitored by a limit switch 76.
When a waste a larger than the volume of the pocket portion 77 of the rotating drum 74 is thrown in, the seal plate 75 is pushed upward and rotates upward, and the displacement is detected by the limit switch 76. Based on the detection of the inclination angle, the fluctuation of the input amount of the waste a is detected, and the rotation speed of the rotary drum 74 is controlled, or the primary air amount, the secondary air amount, the hearth temperature, the furnace temperature, and the like are determined. Controlling.

As described above, by detecting a change in the amount of waste input to the incinerator 71 and performing feedforward control of controlling the combustion conditions in advance based on the change, for example, the generation of CO is suppressed. And stable combustion can be continued.

[0007]

However, although the seal plate 75 is pressed against the rotating drum 74, the pressing force is due to the weight of the seal plate 75, and the pressing force can be easily changed. Can't
The function of forcibly pushing the waste a into the pocket 77 cannot be expected. Therefore, the porosity of each pocket 77 cannot be made constant.

If the waste a rests on the partition plate 79 partitioning the pocket 77, the pressing force is weak, so that a large amount of waste a is thrown in even if the gap in the pocket 77 is large. The sealing plate 75 is inclined upward in the same manner as the above. Because of this, the pocket 7
Even if the gap inside the seal 7 is large, the seal plate 75 may be greatly inclined upward. Therefore, even if the amount of the waste a is small, it may be detected as a large amount of the waste a. It is difficult to accurately predict the amount of waste a from the inclination angle of.

Further, the limit switch 76 determines whether the change amount of the waste a exceeds or does not exceed the set value.
There is also a problem that it is ON-OFF control, and it is difficult to perform fine control according to each displacement amount.

According to the present invention, under the above-described circumstances, the amount (supply value) of the input waste a is accurately predicted, incomplete combustion is reliably prevented, and stable combustion conditions can be set in advance. The task is to

[0011]

In order to solve the above-mentioned problems, the present invention forms a flow chamber in a lower part of an incinerator and a secondary combustion chamber above the flow chamber, and a feeder is provided with a chute through a chute. The above-described fluidized bed in which the waste put into the incinerator is incinerated in the fluidized chamber under the formation of a fluidized bed with primary air, and the unburned gas is burned by the secondary air in the secondary combustion chamber. In the incinerator, a rotary drum for supplying / cutting out the waste is provided in the chute, and a downward pressing plate facing the outer surface of the rotary drum is swingably provided at an upper portion thereof. The board is
Together are biased so as to be in contact with the rotating drum by a spring, it has a detectable by the load cell reaction force to the pressing plate via the spring, on the basis of continuous detection value of the load cell, incineration Predict the amount of waste supplied to the furnace, the predicted value, the amount of the primary air and the secondary air, the amount of waste input by the duster and the rotating drum,
Alternatively, either of the two amounts is controlled.

As described above, if the pressing plate is pushed toward the rotating drum by the spring, the waste is pushed into the rotating drum by the pressing plate by the urging force of the spring. The supply / cutout amount is constant. Further, since the pressing force (reaction force) of the pressing plate is detected by the load cell, the detected value can be obtained continuously, and the continuous detected value changes the waste input amount (supply amount). Can be grasped in detail. Therefore, incineration conditions can be set finely, and efficient combustion can be performed. Also, by replacing the spring, the adjustment of the pressing force by the pressing plate can be performed very easily.

[0013]

[0014] In this configuration, the surface of the rotary drum side of the pressing plate may be provided with a cutting edge waste, if so this <br/>, based on the pressing force, and its cutting blade rotating By the cooperation of the drum, the size of the waste is reduced, the waste is easily stored in the rotating drum, and the supply and cut-out operations are more constant.

[0015]

[0016]

[0017]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a main body of a fluidized bed incinerator. This main body 1 is composed of an upper secondary combustion chamber (free board) 2, a central fluid chamber (primary combustion chamber) 3, and a lower air chamber 4. Has become. 5 is an air pipe to the air chamber 4
Is a primary blower that sends primary air b through
And a bypass air pipe branching off from and connecting to the secondary combustion chamber 2,
Reference numeral 8 denotes a damper for adjusting the flow rate provided at the outlet of the primary blower 5, and 9 denotes a bypass damper provided in the middle of the bypass air pipe 7.

Reference numeral 10 denotes a secondary blower, and secondary air c is sent to the secondary combustion chamber 2 by an air pipe 11 and air pipes 12 and 13 branched from the air pipe 11. The air pipes 12 and 13 are provided with adjustment dampers 14 and 15, respectively. Reference numeral 16 denotes an outlet of the combustion gas d provided at an upper portion of the main body 1.

Reference numeral 17 denotes a dust feeding device such as a screw feeder driven by a motor 18 for feeding waste a to the incinerator main body 1 via a chute 19.

Reference numeral 20 is provided in the middle of the chute 19.
This is a rotating drum for supplying / cutting out the waste a driven by the motor 21. The rotating speed is variable by using an inverter motor or the like for the motor 21. Reference numeral 22 denotes a pressing plate for pressing the rotary drum 20, and a spring (spring) 23.
To the rotary drum 20 side. A damper 24 is provided in the chute 19 below the rotary drum 20.

The damper 24 is closed when the operation of the incinerator starts, ends, or is stopped when an emergency is required. The damper 24 is provided to maintain the airtightness of the furnace and to prevent the temperature inside the furnace from lowering due to radiant heat. During normal operation, the dust feeding device 1
7 is filled with waste a, and the airtightness in the furnace is maintained.

Reference numeral 30 denotes a load cell for detecting the pressing force, reference numeral 31 denotes a converter, reference numeral 32 denotes an arithmetic unit, and reference numerals 33 and 34 denote circuits connecting these. The arithmetic unit 32 includes circuits 35 and 3
6, 37, 38 are connected to the motor 18 of the dust supply device 17, the motor 21 of the rotary drum 20, the bypass damper 9, and the motor 39 of the secondary blower 10, respectively.

Further, a monitor 40 such as an oxygen concentration meter or a thermometer provided at the outlet 16 of the combustion gas d and the arithmetic unit 32, and the adjustment dampers 14 and 15 and the arithmetic unit 32 are connected by circuits 41, 42 and 43, respectively. ing.

The structure around the rotary drum 20 is shown in FIG.
This will be described in more detail. The rotating drum 20 includes a body 20a.
A flange 20b is provided at both ends, and a portion between the flanges 20b is divided by a partition plate 51 provided in a circumferential direction, and a plurality of pockets 52 are formed. Chute 19 on the side of the rotating drum
Is provided with an inspection port 53, and the pressing plate 22 is rotatably supported by a member 54 fixed to the inspection port 53.

Below the inspection port 53, a split cylinder 55 is fixed. One end of the cylinder 55 has a bottom, and the load cell 30 is fixed by an adjustment bolt 56 penetrating the bottom. A slidable block 57 is provided on the other end side in the cylinder 55, and the spring 23 is housed between the load cell 30 and the block 57. The block 57 is connected to the pressing plate 22 via a pin 58. On the upper surface of the pressing plate 22, in order to enhance the effect of compressing and separating the waste a, a plurality of vertical ridges serving as cutting blades are provided. 59 are formed. The shape of the projecting cutting blade is arbitrary, such as a triangular cross section.

It is preferable that the inner surface of the chute 19, the pressing plate 22, etc., where the waste a slides, are appropriately covered with a wear-resistant liner. In this case, the ridge 59 may be formed by welding.

This embodiment has the above configuration, and its operation will be described below.

Now, when air b is sent from the primary blower 5 to the air chamber 4 through the air pipe 6, the air b is blown up to the flow chamber 3 by an air nozzle (not shown), and the air b Allow the medium to flow. For this reason, the waste a input from the lower side of the secondary combustion chamber 2 is burned under the formation of the fluidized bed, and the non-combustibles are discharged from a non-combustible outlet (not shown) provided at the lower part of the fluidized chamber 3 Is more exhausted. In addition, air c is sent from the secondary blower 10 to the secondary combustion chamber 2 through the air pipes 11 and 12, and the unburned gas is completely burned. At this time, the adjustment damper 15 is normally closed.

In the combustion operation described above, in order to completely burn the unburned gas, the opening degree of the adjustment damper 14 provided in the middle of the air pipe 12 is determined by the measurement result of the monitor 40 provided at the outlet 16 of the combustion gas. It adjusts and controls the amount of air sent to the secondary combustion chamber 2. As the monitor for monitoring the combustion conditions, both the above-described oxygen concentration meter and the thermometer are used, and a monitor for monitoring the flare temperature in the furnace is often used.

The waste a is sent from the dust supply device 17 to the secondary combustion chamber 2 through the chute 19, and the fallen waste a in the rotary drum 20 in the middle of the chute 19 is The rotary plate 17 is forcibly pushed into the pocket 52 by the pressing plate 22 urged by the spring 23. At this time, the pressing plate 2
Since a plurality of ridges 59 are provided on the upper surface of 2, even a slightly large lump of waste a is divided and pushed into the pocket portion 52.

The pressing force of the pressing plate 22 is equal to the load cell 3
0 and the spring 23
It can be changed and adjusted with a simple operation of simply replacing the. This makes it possible to adjust the pressure density of the waste a in the pocket portion 52 and the separating force of the waste a by the ridge 59.

The gap (pressure contact) between the rotary drum 20 and the pressing plate 22 is adjusted by adjusting bolts 56 for fixing the load cell 30 and blocks 57 for fixing the spring 23.
The position can be easily changed by adjusting the position. Thus, the supply amount of the waste a can be adjusted.

When the amount of the waste a increases, the waste a cannot be completely pushed into the pocket 52, and the pressing plate 22 rotates around one end of the member 54 as shown by the chain line in FIG. With the movement, the pressing force detected by the load cell 30 increases. This pressing force is always detected, converted into a control signal by the converter 31 and calculated by the calculation device 32. Therefore, the amount of the waste a can be always predicted based on the detection result of the load cell 30.

Further, once the pressing plate 22 rotates,
As shown in FIG. 3A, the wastes a are forcibly pushed into the pockets 52 by the springs 23, so that the porosity of the pockets 52 is less dispersed, and the amount of the wastes a can be accurately predicted. . Further, since the waste a is forcibly divided by the ridges 59 and pushed into the pocket 52, the waste a does not get on the partition plate 51 despite the large gap in the pocket 52. . That is, waste a
Although the amount of waste a is small, there is no possibility that a malfunction that the amount of waste a is determined to be large due to the waste a riding on the partition plate 51 will occur.

As described above, the amount of the waste a can be accurately predicted, so that appropriate combustion control can be performed based on the prediction. That is, in the normal case where the amount of the waste a is almost quantitative, the amount of air sent to the secondary combustion chamber 2 is measured based on the measurement result of the monitor 40 provided at the outlet 16 of the combustion gas d as in the conventional case. c is controlled by controlling the opening degree of the adjustment damper 14, and the unburned gas is completely burned.

On the other hand, when the pressing force detected by the load cell 30 is larger than usual and the amount of waste sent to the incinerator main body 1 is determined to be "excessive", the combustion gas d
Of the monitor 40 provided at the exit 16 of the
Incomplete combustion cannot be avoided only by controlling the amount c of air sent to the secondary combustion chamber 2.

Therefore, an appropriate amount of secondary air is calculated from the result of the estimation of the amount of waste a, and an appropriate amount of air is supplied to the secondary combustion chamber 2. Specifically, the motor 3 of the secondary blower 10
9 to control the adjusting damper 14 to be fully opened, and the normally-closed adjusting damper 15 to control the opening to adjust the opening degree so that the secondary combustion chamber 2 has an appropriate amount of air. c and c ′. At this time, since the pressing force is always detected by the load cell 30 and the fluctuation of the amount of the waste a is constantly predicted, the amount of air sent to the secondary combustion chamber 2 is always adjusted to an appropriate state based on this prediction. Control.

As described above, the amount of the waste a to be supplied is predicted, and an appropriate amount of the air c and c ′ is previously supplied to the secondary combustion chamber 2.
, So that incomplete combustion can be avoided and stable combustion can be maintained.

Further, as shown in FIG. 3 (b), a large amount of waste a is fed in and cannot be dealt with by the pressing force, and the pressing force detected by the load cell 30 is larger than a preset value, so that When the amount of waste a is determined to be “excess”, unlike the case where the amount of waste a is determined to be “excessive”, an appropriate amount of air c is stored in the secondary combustion chamber 2. , C 'cannot be avoided only by supplying incomplete combustion.

Therefore, the bypass damper 9 which has been completely closed until now is used.
And a part b ′ of the air b pushed in from the primary blower 5 is sent into the secondary combustion chamber 2. This allows
The fluid of the fluid medium in the fluidizing chamber 3 is reduced, and the waste a
Is suppressed, and unburned gas, which increases when a large amount of waste a burns, is completely burned by adding air b ′ sent into the secondary combustion chamber 2 by adjusting the opening degree of the bypass damper 9. .

Further, the number of rotations of the motor 18 of the dust supply device 17 and the motor 21 of the rotary drum 20 is controlled, the amount of waste a supplied to the secondary combustion chamber 2 is suppressed, and the amount of waste a supplied is reduced. Stabilize.

At this time, the air volume of the secondary blower 10 is maximum, and the adjustment dampers 14 and 15 are fully opened. If necessary, the air volume and the degree of opening are controlled to control the air volume to the secondary combustion chamber 3. Adjust c and c '.

In this control, since the pressing force is always detected by the load cell 30, the air amount b, b ',
The adjustment of c and c ′ and the supply amount of the waste a can always be controlled to an appropriate state. In addition, these air amount b, b ', c, c'
And the control of the supply amount of the waste a can be performed on only one of them or both simultaneously.

[0044]

As described above, according to the present invention, the amount of waste can be accurately predicted, and appropriate feedforward control can be performed. That is, when the amount of waste is “excessive,” the amount of air sent to the secondary combustion chamber is always controlled to an appropriate state, incomplete combustion can be avoided, and stable combustion is maintained. It is possible. Also,
If the amount of waste is “excess”, a part of the air sent to the fluidized chamber is sent to the secondary combustion chamber to control the combustion rate in the fluidized chamber, or to control the dusting device and rotating drum. In addition, it is possible to maintain stable combustion by suppressing the amount of waste supplied.

Further, the change in the amount of waste supplied can be grasped in detail, and the amount of waste supplied by the rotating drum is also fixed.

Therefore, according to the present invention, complete combustion in the incinerator can be achieved over the entire incineration time while maintaining stable combustion.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of the embodiment.

FIG. 3 is a diagram illustrating the operation of the embodiment.

FIG. 4 is a schematic view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 The main body of a fluidized bed incinerator 2 Secondary combustion chamber 3 Flow chamber (primary combustion chamber) 4 Air chamber 5 Primary blower 6 Air pipe 7 Bypass air pipe 10 Secondary blower 11, 12, 13 Air pipe 16 Outlet of combustion gas Reference Signs List 17 Dust supply device 19 Chute 20 Rotary drum 22 Press plate 23 Spring (spring) 24 Damper 30 Load cell 32 Arithmetic device 51 Partition plate 52 Pocket portion 59 Protrusion (cutting blade)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI F23K 3/00 302 F23K 3/00 302 (72) Inventor Toshikazu Oe 1-12-19 Kitahorie, Nishi-ku, Osaka City Kurimoto Iron Corporation Inside the factory (72) Inventor Chisato Dono 1-12-19 Kitahorie, Nishi-ku, Osaka-shi Inside the Kurimoto Iron Works Co., Ltd. (56) References JP-A-4-273911 (JP, A) JP-A-8-61623 ( JP, A) JP-A-3-191203 (JP, A) JP-A-5-222314 (JP, A) Fully open Showa 53-114879 (JP, U) Fully open Flat 4-138526 (JP, U) Fully open Hei 5-96733 (JP, U)

Claims (1)

(57) [Claims] 1. A flow chamber 3 is formed in the lower part of the incinerator 1 and a secondary combustion chamber 2 is formed above the flow chamber 3, and the waste introduced into the incinerator 1 from the duster 17 via the chute 19. Thing a
Is incinerated in the fluidized chamber 3 under the formation of a fluidized bed by primary air, and the unburned gas is burned by the secondary air in the secondary combustion chamber 2. And a rotary drum 20 for supplying and cutting out the waste a, and the rotary drum 2
A downward pressing plate 22 opposing the outer surface is swingably provided at its upper portion, and the pressing plate 22 is urged by a spring 23 so as to be in contact with the rotary drum 20 and is pressed to the pressing plate 22. Can be detected by the load cell 30 via the spring 23. Based on the continuous detection value of the load cell 30, the supply amount of the waste a to the incinerator 1 is predicted, and the predicted value is calculated. By
A fluidized bed incinerator characterized by controlling the amount of the primary air and the secondary air, the amount of the waste a charged by the duster 17 and the rotating drum 20, or both of them.