JP2000002412A - Refuse incineration equipment and its operation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion control method and a device for a refuse incineration equipment which permits a stable supply of refuse to an incinerator and prevention of generation of harmful substances, such as dioxin. SOLUTION: Provided are a dust feeding device 3 and in its downstream a measuring conveyor 16 so that the refuse delivered from the dust feeding device 3 to the measuring conveyor 16 is supplied to an incinerator by the following two supplying methods. When the dust-feeding device 3 is normally operated, a predetermined amount of refuse is constantly supplied to the incinerator via the measuring conveyor 16. When compaction of refuse at an exhaust port 6 of the dust feeding device 3 starts and the degree of compaction becomes high, a screw shaft 5 of the dust feeding device 3 is reversely rotated to reversely feed the refuse so as to dissolve the compaction state of the refuse. The refuse that is reversely fed is supplied to the incinerator via the measuring conveyor 16 from an outlet headed toward a refuse returning chute 13 provided other than the exhaust port that is for the time of normal operation of the dust feeding device 3. In this case, a combustion air supplying volume of the incinerator is adjusted according to the amount of refuse measured by means of the measuring conveyor 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust-feeding device for pumping refuse such as municipal waste and various industrial wastes (hereinafter, these may be simply referred to as refuse), and a refuse fed from the dust-feeding device. The present invention relates to a refuse incineration facility provided with an incinerator for incineration and an operation method thereof.

[0002]

2. Description of the Related Art FIG. 2 shows a schematic view of a conventionally known refuse incinerator. As shown in FIG.
The garbage such as the municipal refuse stored in the hopper is thrown into the hopper 4 of the dust feeding device 3 by the crane 2. The dust supply device 3 sends the dust received by the hopper 4 to the discharge port 6 side by rotation of a screw shaft 5 provided at the bottom of the hopper 4, and discharges the dust discharged from the discharge port 6 through a discharge chute 7. Into the incinerator 8. The refuse introduced into the incinerator 8 is burned by the combustion air supplied from the blower 9. Exhaust heat generated by the combustion of the refuse in the incinerator 8 is separated into ash and exhaust gas by a dust collector (not shown) provided in the flue 10, and each is discharged out of the system. Further, the incombustibles in the incinerator 8 are discharged to the incombustible discharge device 11.
Is discharged out of the system.

It is necessary to supply the amount of dust from the dust supply device 3 to the incinerator 8 so that stable and good combustion can be obtained. By the way, depending on the nature of the refuse supplied to the dust-supplying device 3, the compaction state of the refuse in the dust-supplying device 3 becomes abnormally high. There is a case where so-called falling off occurs at a stretch in the incinerator 8. When such a phenomenon occurs, the amount of refuse charged into the incinerator 8 rapidly becomes excessive, and it becomes impossible to maintain a preferable refuse combustion state, and carbon monoxide (CO) and nitrogen oxides (N
Hazardous substances such as Ox) are likely to be generated. Also, CO
When a large amount of dioxin (DXN) precursors such as methane and chlorobenzene are generated, NaCl and H contained in
Reacts with Cl, leading to resynthesis of dioxin.

In order to prevent the above-mentioned inconveniences and to maintain a normal combustion state in the incinerator 8, dust is not dropped from the dust supply device 3 into the incinerator 8 without falling off. Stable supply is required.

[0005]

In the above-mentioned prior art, when the compaction state of the dust occurs in the dust feeding device 3, the compaction of the dust is performed based on the detection result of the current value of the drive motor (not shown) of the screw shaft 5. It is determined that the load on the motor has increased, and the screw shaft 5 is rotated in the reverse direction to eliminate the clogging of dust in the dust feeding device 3.

The refuse sent back by the screw shaft 5 passes through the chute 13 and is returned to the refuse pit 1. Therefore,
While the screw shaft 5 is rotating in the reverse direction, no refuse is supplied into the incinerator 8 and the amount of combustion air supplied from the blower 9 into the incinerator 8 does not match. Becomes excessive and the temperature in the incinerator drops to 700 ° C or less,
The peak of the CO concentration is 5000pp by combustion of the residual refuse.
Inconvenience such as increase to about m is likely to occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned disadvantages of the prior art, and an object thereof is to enable a stable supply of refuse to an incinerator and reduce the generation of harmful substances such as dioxins. An object of the present invention is to provide a refuse incineration facility and a method for operating the same.

Another object of the present invention is to solve the above-mentioned disadvantages of the prior art, and to reduce the amount of waste supplied to the incinerator even when the waste in the dust feeding apparatus becomes compact. It is an object of the present invention to provide a method and an apparatus for stably burning refuse supplied to an incinerator while minimizing the condition.

[0009]

In order to achieve the above object, the present invention provides a dust feeding device and a weighing / conveying device downstream thereof, and the weighing / conveying device generates the following two types of refuse from the dust feeding device. Is supplied to the incinerator by the above-mentioned supply method. (1) When the dust supply device is operating normally, a predetermined amount of refuse is always supplied to the incinerator via the measuring and conveying device. (2) Consolidation of the refuse at the discharge port of the dust supply device starts, and when the pressure density increases, the garbage conveying means (such as a screw shaft) of the dust supply device is reversed, and the refuse is conveyed, and the compaction state of the refuse is reduced Waste is supplied to the incinerator via the metering and conveying device from an opening provided separately from the discharge port during normal operation of the dust supply device.

[0010] Thus, the present invention enables the entire amount of waste to be supplied to the incinerator under any operating conditions.

At this time, the weight (or volume) of the refuse supplied to the weighing conveyor is measured, and the increase / decrease of the weight controls the transfer speed (such as the number of rotations of a screw shaft) of the refuse transfer means of the dust feeding apparatus. By stabilizing the amount of refuse supplied to the incinerator via the refuse transporting means (such as a screw shaft) and the weighing conveyor, the amount of refuse supplied to the incinerator can be controlled according to the amount of refuse actually supplied to the incinerator. The amount of air supplied to the incinerator is controlled so that the amount of combustion air does not become excessive or insufficient, thereby enabling stable combustion of refuse in the incinerator and reducing or preventing generation of harmful substances.

[0012]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an internal configuration diagram of a dust supply device applied to the refuse incineration equipment of the present embodiment. The dust feeding device 3 shown in FIG. 1 is applied to the waste incineration equipment already described with reference to FIG. 2, and a screw shaft 5 for dust transport is provided at the bottom of the hopper 4 of the dust feeding device 3. A pressure gauge 21 is provided in the dust seal portion 14 of the discharge port 6 of FIG. Further, at the end of the hopper 4 opposite to the discharge port 6, an outlet to a dust return chute 13 for returning dust to the dust pit 1 (see FIG. 2) is provided. Is provided with a flap damper 12 that opens the outlet to the dust return chute 13 by the weight of the dust.

Below the outlet 6 of the hopper 4 and the outlet to the waste return chute 13, a weighing conveyor 16 is disposed over both of the openings. The weighing conveyor 16 is provided with a weigh scale 17 so that the weight of the refuse falling onto the weighing conveyor 16 from the outlet of the hopper 4 and / or the outlet to the refuse return chute 13 can be measured. . The refuse supplied on the weighing conveyor 16 is transported to the incinerator 8 (see FIG. 2).

The weight of the refuse on the weighing conveyor 16 is detected by a weighing scale 17, and a control unit 18 for controlling the rotation speed of the screw shaft 5 based on the detected value drives and controls the motor 20 for driving the screw shaft 5. Is done. Further, the amount of combustion air supplied to the incinerator by the push-in blower 9 is controlled by the detection value of the weigh scale 17.

The dust supplied to the dust feeding device 3 shown in FIG. 1 is sent to the discharge port 6 of the hopper 4 by the forward rotation of the screw shaft 5, but the amount of the dust supplied increases, and the compaction of the dust seal portion 14 is performed. When the state becomes high, the pressure gauge 21 detects a pressure equal to or higher than a predetermined value (A). When the detection value of the pressure gauge 21 exceeds the predetermined value (A), the screw shaft 5 is rotated in the reverse direction to feed back some of the dust. By this reverse feeding, the dust reaches the exit to the dust return chute 13. As a result, the flap damper 12 is opened, and the refused dust is dropped on the weighing conveyor 16. Garbage that has fallen onto the weighing conveyor 16 from the outlet to the refuse return chute 13 is weighed by the weighing conveyor 16.
And sent to the discharge port 6 of the hopper 4 to be supplied to the incinerator 8.

The screw shaft 5 is rotated in the reverse direction so that some of the refuse is sent back, and the refuse is returned to the refuse return chute 1.
No waste is supplied to the incinerator 8 by the time the dust is dropped onto the weighing conveyor 16 from the outlet to the incinerator 3 and is sent to the discharge port 6 of the hopper 4. The amount of combustion air to 8 is reduced to the minimum required to fluidize the fluidized bed of the incinerator 8.

The above will be described with reference to FIGS. 4A shows the relationship between the amount of waste supplied to the incinerator 8 and time, and FIG. 4B shows the relationship between the amount of primary air supplied to the incinerator 8 and time.

When the supply amount of the dust increases and the pressure gauge 21 detects a pressure equal to or higher than the predetermined value A, the screw shaft 5 is rotated in the reverse direction so that the dust is sent backward, and at this time, the weighing conveyor is passed through the outlet to the dust return chute 13. The garbage falls on 16 and its weight W ₂ (kg / h) is measured. Then, dust on the weighing conveyor 16 is after t ₁ hour is supplied to the incinerator 8. When the pressure gauge 21 detects a pressure of a predetermined value B (A> B: A, the value of B is set so as to prevent hunting of the motor 20 for driving the screw shaft 5), the screw shaft 5 is rotated forward. Then, refuse having a weight W ₁ (kg / h) in a normal state is sent to the incinerator 8 from the discharge port 6 of the hopper 4.

[0019] Since at all refuse in the incinerator 8 between the t ₁ hour is not supplied combustion air quantity to the incinerator 8 it will be narrowed down to required minimum. The weight W ₂ (kg) on the weighing conveyor 16 is maintained until the screw shaft 5 is rotated forward.
/ H) is supplied to the incinerator 8, and during this time, the amount of combustion air supplied to the incinerator 8 is weight W ₂ (kg / kg).
h) corresponds to the waste.

As a driving method of the screw shaft 5, an operation by a combination method as shown in FIG. 5 can be performed.

In FIG. 5, two screw shafts 5a,
In the case of a dust feeding apparatus having a screw shaft 5b, (1) a method in which only the screw shaft 5a can be rotated in the reverse direction and the other screw shaft 5b is kept in the normal rotation, or (2) both the screw shafts 5a and 5b are rotated in the normal direction. The system can be reversed. In the case of the operation method (1), the dust seal portion 1 of the hopper 4
While releasing the consolidation at 4, on the other hand, refuse can be continuously supplied to the incinerator 8 from the discharge port 6 of the hopper 4.

In the case of the operation method (1), as shown in FIGS. 6 and 7, the supply amount of dust increases and the pressure gauge 21 changes to a predetermined value A.
When the above pressure is detected, the screw shaft 5a is rotated in the reverse direction to feed the dust in the reverse direction. During this time, the screw shaft 5b is also rotated in the normal direction, falls on the weighing conveyor 16, and has a weight W ₃ (k).
g / h) is measured and then supplied to the incinerator 8. On the other hand, reverse feeding is garbage by the reverse rotation of the screw shaft 5a is dropped from the outlet of the dust return chute 13 onto the weighing conveyor 16, the weight W _{4 (kg} / h) is measured.

Then, the weight W on the weighing conveyor 16
₄ (kg / h) waste is after _{t 1} hour the weight _{W 3}
(Kg / h) and is supplied to the incinerator 8. When the pressure gauge 21 detects the pressure of the predetermined value B (A> B), the screw shaft 5 is rotated forward, and the weight W ₁ (kg
/ H) is sent to the incinerator 8 through the discharge port 6 of the hopper 4. During the time t ₁ , the weight W ₃ (k
g / h) of refuse, the weight of the refuse W ₃ (k
g / h) is supplied to the incinerator 8. Thereafter, until the screw shaft 5 is rotated forward, refuse having a weight W ₄ (kg / h) and refuse having a weight W ₃ (kg / h) on the weighing conveyor 16 are supplied to the incinerator 8.
During this time, the amount of combustion air supplied to the incinerator 8 is set to an amount corresponding thereto.

Thus, the dust seal portion 14 of the hopper 4
While the consolidation at
Can supply refuse to the incinerator 8.

As described above, the weighing machine 17 of the weighing conveyor 16 is used.
It is possible to make the amount of air of the forced blower 9 into an amount corresponding to the amount of refuse supplied to the incinerator 8 through the air amount control unit 19 of the forced blower 9, It is possible to maintain a good combustion state. As a result, consolidation of the refuse in the hopper 4 and so-called refuse dropping of the refuse into the combustion furnace 8 do not occur, and generation of harmful substances such as dioxin can be reduced or prevented.

In the control of the amount of combustion air supplied to the combustion furnace 8, even if the amount of fluidizing air in the fluidized bed of refuse is fixed and only the amount of primary air and / or the amount of secondary air is controlled, combustion control is performed. Is effective.

[0027]

According to the present invention, a good amount of combustion air can be supplied to an incinerator in accordance with the amount of waste supplied, so that a good combustion state of waste can always be maintained, and generation of unburned components and generation of CO can be suppressed. It can prevent the generation of harmful substances such as dioxin.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a dust supply device applied to a refuse incineration plant according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a waste incineration facility.

FIG. 3 is a configuration diagram of a dust supply device applied to the refuse incineration equipment according to the embodiment of the present invention.

FIG. 4 is a diagram illustrating an operation method of the dust supply device shown in FIG.

FIG. 5 is a configuration diagram of a two-shaft type screw shaft of the dust feeding apparatus according to the embodiment of the present invention.

FIG. 6 is a configuration diagram of a dust supply device applied to the refuse incineration plant according to the embodiment of the present invention.

FIG. 7 is a view for explaining an operation method of the dust feeding apparatus shown in FIG.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 garbage pit 2 crane 3 dust supply device 4 hopper 5 screw shaft 6 hopper discharge port 7 discharge chute 8 incinerator 9 push-in blower 10 flue 11 incombustibles discharge device 12 flap damper 13 refuse return chute 14 refuse seal section 15 rotary seal 16 Weighing conveyor 17 Weigh scale 18 Revolution control unit 19 Air flow control unit 20 Motor

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Nobuyuki Kobayashi 1-2-1-10 Isogo, Isogo-ku, Yokohama-shi, Kanagawa F-term in Babcock Hitachi, Ltd. Yokohama Engineering Center (reference) 3K062 AA11 AB01 AC01 BA02 CB01 DA11 DA31 DA32 DB01 DB07 3K065 AA11 AB01 AC01 BA02 BA06 EA06 EA15 EA23

Claims (3)

[Claims] 1. A dust feeding apparatus comprising: transport means for transporting refuse; a discharge port for discharging refuse by the transport means; and an opening provided near an end opposite to the discharge port. A dust-tightness detection device provided at the discharge port of the dust-feeding device and detecting the compaction state of the dust at the discharge port; and transporting the dust-feeding device within a predetermined pressure value range of the dust detected by the dust-tightness detection device. A control device for the conveying means for driving the means in the reverse direction, and a device provided below the dust-feeding device, which measures the dust and discharges the dust to the discharge outlet of the dust-feeding device over the discharge port and the opening of the dust-feeding device. Via a weighing / conveying device that conveys the air toward the hopper, a control device that controls the amount of combustion air in accordance with the amount of refuse supplied by the weighing / conveying device, and a discharge port of the dusting device using the combustion air. To incinerate refuse supplied A refuse incineration facility comprising an incinerator. 2. The dust conveying means of the dust feeding device is composed of two screw shafts, and either of the two screw shafts is capable of normal rotation and reverse rotation, or one of the screw shafts is capable of only normal rotation. 2. The refuse incineration plant according to claim 1, wherein the other screw shaft has a structure capable of normal rotation and reverse rotation. 3. A dust feeding apparatus comprising: transport means for transporting refuse; a discharge port for discharging refuse by the transport means; and an opening provided near an end opposite to the discharge port. A dust-tightness detection device provided at the discharge port of the dust-feeding device for detecting the compaction state of the dust at the discharge port; and a dust-tightness detection device provided below the dust-feeding device for measuring the waste and discharging the dust. This is a method of operating a waste incineration facility equipped with a weighing / conveying device that conveys to the outlet and an incinerator that incinerates the refuse supplied through the discharge port of the dust supply device, and is detected by a consolidation detection device. Until the pressure of the refuse becomes the first predetermined pressure value, the conveying means of the dust feeding device is driven in the forward direction to supply refuse to the weighing and conveying device from the discharge port of the dust feeding device, and When the pressure exceeds a first predetermined pressure value, By driving the conveying means location in the opposite direction,
The refuse is supplied to the weighing and conveying device from an opening provided near the end opposite to the discharge port of the dust supply device, and when the pressure of the refuse decreases to the second predetermined pressure value, The conveying means of the dust feeding device is driven in the forward direction to supply refuse to the weighing / conveying device from the discharge port of the dust feeding device, and the combustion of the incinerator according to the supply amount of refuse on the weighing / conveying device in each of the conveying motes. A method of operating a refuse incineration plant, characterized by controlling the amount of air for use.