JP3811322B2 - Incineration equipment for combustible dust in waste melting furnaces - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a waste melting furnace for pyrolyzing and melting waste such as general waste and industrial waste.
[0002]
[Prior art]
As a waste disposal method such as general waste and industrial waste, waste is charged into a shaft furnace type waste melting furnace, and the waste is dried, preheated, pyrolyzed, combusted, melted, slag and metal There is known a thermal decomposition melting method to be taken out as
[0003]
In the operation of the waste melting furnace, the combustible component in the charge is thermally decomposed in the furnace to generate a residue. The generated pyrolysis residue is combusted by the air sent from the tuyere or accumulated in the furnace, but the fine one is not burned by the air sent from the tuyere, Ride as a flammable dust from the furnace.
[0004]
Japanese Laid-Open Patent Publication Nos. 8-285250 and 9-79546 disclose a method for blowing combustible dust from a tuyere into a melting furnace as a technique for treating scattered combustible dust.
[0005]
FIG. 3 is a schematic view of a waste melting treatment facility for treating the combustible dust described in the publication. In the lower part of the waste melting furnace 1, a plurality of lower tuyere 2 and upper tuyere 3 are arranged around the furnace. From the lower tuyere 2, oxygen-enriched air is blown into the furnace in order to burn the coke that has descended to the furnace bottom. Air is blown from the upper tuyere 3 to burn the pyrolyzed combustible material.
[0006]
Among the residues generated by thermal decomposition of combustible materials in the waste melting furnace 1, combustible dust scattered from the top of the furnace passes through the exhaust gas pipe 4 at the top of the furnace and is removed by a dust remover such as a cyclone. 5, collected, and stored in the combustible dust hopper 6.
[0007]
The combustible dust in the combustible dust hopper 6 is cut out by the cutting device 7, mixed with the carrier air of the blower 8 by the mixer 9, and sent to the distributor 10.
[0008]
The combustible dust distributed to each upper tuyere 3 by the distributor 10 is blown into the waste melting furnace 1 together with air. After the combustible dust scattered from the top of the waste melting furnace 1 is collected, the collected combustible dust is burned in front of the upper tuyere 3 so that this combustion is used for drying the charge and Since it becomes a heat source for raising the temperature, it becomes possible to reduce auxiliary fuel such as coke, which has conventionally been a heat source for drying and melting the charge.
[0009]
[Problems to be solved by the invention]
However, since the temperature of combustible dust is usually high and there is a risk that combustible dust may burn when transported using air, at present, inert gas is used instead of air. Has the disadvantage of being expensive.
[0010]
In addition, when the carrier air is used, there is a problem that when the combustible gas flows from the dust remover to the combustible dust blowing device, the blowing device may come into contact with the carrier air and burn. Further, when the carrier air flows into the combustible dust hopper, there is a possibility that the combustible dust hopper burns.
[0011]
Therefore, the present invention provides a combustible dust blowing facility capable of transporting combustible dust with air without using an expensive inert gas and preventing inflow of combustible gas and transport air.
[0012]
[Means for Solving the Problems]
The combustible dust blowing equipment for the waste melting furnace of the present invention collects the combustible dust from the shaft furnace type waste melting furnace, cuts out the collected combustible dust from the combustible dust hopper, and is combustible. In a facility for injecting combustible dust in a waste melting furnace that is transported to a dust blowing device and blown into the furnace through a tuyere by air transport, the combustible dust between the combustible dust hopper and the combustible dust blowing device A water-cooled transport device for cooling combustible dust is provided in the transport path, and a hopper having dampers at the upper and lower portions is provided in the transport path between the water-cooled transport device and the combustible dust blowing device. It is characterized by.
[0013]
In the above configuration, a flammable dust sieving device may be arranged upstream or downstream of the water-cooled conveying device, and a combustible dust conveying path is provided between the combustible dust hopper and the combustion chamber, A combustible dust transport path and a combustible dust transport path between the combustible dust hopper and the combustible dust blowing device may be switchable.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic view showing an embodiment of the present invention. The same components as those shown in FIG. 3 are denoted by the same reference numerals, and the description thereof is omitted.
[0015]
A combustible dust hopper 6 for temporarily storing combustible dust is installed below a dust remover 5 such as a cyclone that collects combustible dust generated and scattered in the waste melting furnace 1.
[0016]
A screw conveyor 12 is disposed under the combustible dust hopper 6 as a cutting device for cutting out the combustible dust supplied to the tuyere 24. The combustible dust hopper 6 includes a weight indicator WI for measuring the weight of combustible dust in the combustible dust hopper 6, and a motor for the screw conveyor 12 for adjusting the weight of combustible dust taken out from the screw conveyor 12. A weight indicating controller WIC for adjusting the number of rotations is provided.
[0017]
The screw conveyor 12 is connected by a pipe 15 via a water-cooled conveying device for cooling combustible dust, for example, a water-cooled screw conveyor 13 and a switching damper 14. The water-cooled transfer device is not limited to a water-cooled screw feeder, and a water-cooled vibration feeder, a water-cooled paddle conveyor, or the like may be used.
[0018]
The water-cooled screw conveyor 13 is connected to the combustible dust blowing device 16 and the pipe 18 via an intermediate hopper 17 including an upper damper 17a and a lower damper 17b in order to send the combustible dust to the combustible dust blowing device 16. Yes. The intermediate hopper 17 is provided to prevent the combustible gas and the carrier air from flowing backward. The intermediate hopper 17 is provided with a duct 17c for blowing an inert gas used for pressure equalization, and an inert gas blowing valve 17d. The pipe 18 is provided with a temperature indicator TI for measuring the temperature of the combustible dust after cooling.
[0019]
The combustible dust blowing device 16 is provided with, for example, a circle feeder 19 as a distributor for blowing combustible dust into the tuyere 24 by the blower 8.
[0020]
In addition, in order to remove a large block or the like that hinders conveyance from the combustible dust, an appropriate place between the combustible dust hopper 6 and the combustible dust blowing device 16, for example, a water-cooled screw conveyor 13 and The sieving device 20 may be arranged in a pipe 18 between the combustible dust blowing device 16 or a pipe 15 between the combustible dust hopper 6 and the water-cooled screw conveyor 13. Large lumps and the like on the sieve are received in a container, passed through a garbage pit, or kneaded and granulated with dust collected in the downstream and charged from the top of the furnace. In addition, you may mix this combustible dust with the combustible dust which blows, after crushing.
[0021]
The combustible dust blowing device 16 includes a weight indicator WI for measuring the weight of the combustible dust in the combustible dust blowing device 16 and a circle feeder 19 for adjusting the weight of the combustible dust supplied to the tuyere 24. A weight indicating controller WIC for adjusting the number of rotations by the motor M is provided. Furthermore, a pressure indicator PI is provided for measuring the blowing pressure.
[0022]
Next, a method for supplying combustible dust will be described.
[0023]
When the weight indicator WI confirms that a predetermined amount of combustible dust is stored in the combustible dust hopper 6, the damper 14 of the pipe 15 is opened, the upper damper 17a of the intermediate hopper 17 is opened, and the lower damper 17b is closed. In this state, the motor M is driven to rotate the screw conveyor 12, and combustible dust is sent to the water-cooled screw conveyor 13. The combustible dust is cooled to a temperature at which the water-cooled screw conveyor 13 does not ignite, for example, about 40 ° C., and falls to the lower damper 17 b of the intermediate hopper 17.
[0024]
The amount of combustible dust supplied is adjusted while adjusting the rotation speed of the motor M with the weight indicating controller WIC of the combustible dust hopper 6. When the cutting of the predetermined amount of combustible dust is completed, the upper damper 17a of the intermediate hopper 17 is closed.
[0025]
Thereafter, in order to perform pressure equalization with the combustible dust blowing device 16 in the intermediate hopper 17, the inert gas blowing valve 17d is opened, the lower pressure equalizing valve 17e is opened, and the lower damper 17b is opened to remove the combustible dust. The blower 16 is charged.
[0026]
After charging, the lower damper 17b, the inert gas blowing valve 17d, and the lower pressure equalizing valve 17e are closed, and the intermediate hopper 17 is pressure-equalized with the pipe 18, so the upper pressure equalizing valve 17f is opened to confirm that the pressure has been equalized. Then, the upper pressure equalizing valve 17f is closed and the upper damper 17a is opened.
[0027]
The subsequent operations of the upper damper 17a and the lower damper 17b are repeated.
[0028]
The combustible dust in the combustible dust blowing device 16 adjusts the blowing amount of each tuyere 24 by adjusting the rotation speed of the circle feeder 19 by the motor M with the weight indicating controller WIC.
[0029]
The melting furnace 1 may be blown by inserting a lance or the like to the tip of the tuyere and blowing directly into the furnace, or may be blown together with air sent from the tuyere 24 or oxygen-enriched air.
[0030]
In the present invention, since the combustible dust is cooled to about 40 ° C. by the water-cooled screw conveyor 13, the combustible dust does not burn before being blown into the melting furnace. Further, the intermediate hopper 17 prevents the combustible gas from flowing into the combustible dust blowing device 16, and the carrier air does not flow into the combustible dust hopper 6.
[0031]
FIG. 2 is a diagram showing another embodiment of the present invention. The same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.
[0032]
The screw conveyor 12 of the combustible dust hopper 6 is connected to the water-cooled screw conveyor 13 for cooling the combustible dust by a pipe 15 via a switching damper 14 and also injects combustible dust into the combustion chamber 21. It is connected to the combustion chamber screw conveyor 22 via a switching damper 23. The supply to the water-cooled screw conveyor 13 on the blowing side and the screw conveyor 22 for the combustion chamber is performed by rotating the screw conveyor 12 forward or reverse, and at that time, the dampers 14 or 23 on the side carrying the combustible dust. Open and close the other damper. The amount of supply to the combustion chamber 21 by the screw conveyor 22 for the combustion chamber is performed while adjusting the number of revolutions of the motor M with the weight indicating controller WIC.
[0033]
The present invention can be applied not only to an integral shaft furnace type pyrolysis melting furnace used for waste pyrolysis melting treatment, but also to a furnace in which pyrolysis and melting furnace are separated.
[0034]
【The invention's effect】
The present invention cools combustible dust with a water-cooled transport device and prevents inflow of combustible gas and transport air with a hopper having dampers at the top and bottom, so that it is inexpensive without using expensive inert gas. Combustible dust can be blown by air conveyance.
[0035]
Further, if the apparatus of the present invention is provided with a sieving apparatus, it is possible to remove a large lump of collected dust and the like, and blockage in the blowing apparatus and the conveyance system path can be prevented.
[0036]
Moreover, when stopping blowing of combustible dust on account of operation, combustible dust can be switched from the blowing side to the combustion chamber side by reversing the screw conveyor of the combustible dust hopper from normal rotation.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an embodiment of the present invention.
FIG. 2 is a diagram showing another embodiment of the present invention.
FIG. 3 is a schematic view of a conventional waste melting treatment facility for treating combustible dust.
[Explanation of symbols]
1: Waste melting furnace 2: Lower tuyere 3: Upper tuyere 4: Exhaust pipe 5: Dust collector 6: Combustible dust hopper 7: Cutting device 8: Blower 9: Mixer 10: Distributor 12: Screw conveyor 13: Water-cooled screw conveyor 13a: Duplex casing 13b: Screw shaft 14: Switching damper 15: Piping 16: Combustible dust blowing device 17: Intermediate hopper 17a: Upper damper 17b: Lower damper 17c: Duct 17d: Not Active gas blowing valve 17e: Lower pressure equalizing valve 17f: Upper pressure equalizing valve 18: Piping 19: Circle feeder 20: Sieve device 21: Combustion chamber 22: Screw conveyor 23: Switching damper 24: Tuyere

Claims (4)

Combustible dust from a waste melting furnace is collected, the collected combustible dust is cut out from a combustible dust hopper, transported to a combustible dust blowing device, and combustible in a waste melting furnace blown by air transport from a tuyere In the dust dust blowing equipment,
A water-cooled conveying device for cooling the combustible dust is provided in the combustible dust conveying path between the combustible dust hopper and the combustible dust blowing device, and the water-cooled conveying device and the combustible dust blowing device are provided. A facility for injecting combustible dust in a waste melting furnace, characterized in that a hopper having dampers at the upper and lower parts is provided in the conveying path between the two. The combustible dust blowing device for a waste melting furnace according to claim 1, wherein a combustible dust sieving device is arranged upstream or downstream of the water-cooled conveying device. A combustible dust transport path is provided between the combustible dust hopper and the combustion chamber, the combustible dust transport path, and the combustible dust transport path between the combustible dust hopper and the combustible dust blowing device. The facility for injecting combustible dust in a waste melting furnace according to claim 1 or 2, characterized in that can be switched. The inert gas blowing duct for pressure equalization is provided in the hopper provided in the conveyance path between the water-cooled type conveying device and the combustible dust blowing device. Equipment for injecting combustible dust in the waste melting furnace described.

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