JP3838725B2 - Method for cooling thermal decomposition residue in waste treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for cooling a pyrolysis residue in a waste treatment apparatus. More specifically, the waste is heated and pyrolyzed to produce dry distillation gas and a pyrolysis residue mainly composed of nonvolatile components. After the residue is cooled, it is separated into a combustible component and a non-combustible component, and the pyrolysis residue of the waste treatment apparatus in which the dry distillation gas and the combustible component are combusted in a combustion melting furnace. It relates to a cooling method.
[0002]
[Prior art]
Waste is put into a pyrolysis reactor and heated in a low-oxygen atmosphere under atmospheric pressure as one of the waste treatment equipment for municipal waste and other general waste and industrial waste containing combustibles such as waste plastic. And pyrolyzing to produce dry distillation gas and pyrolysis residue mainly composed of non-volatile components, and further cooling the pyrolysis residue and then supplying to the separation device with combustible components mainly composed of carbon, for example, Separated into non-combustible components such as rubble such as metal, ceramics, gravel, concrete pieces, etc., combusted the combustible components, and combusted in a combustion melting furnace For example, Japanese Patent Publication No. 6-56253 proposes a waste treatment apparatus in which the generated combustion ash is made into molten slag and the molten slag is discharged and cooled and solidified.
[0003]
By the way, in such a waste treatment apparatus, since the pyrolysis residue discharged from the pyrolysis reactor is as high as about 450 ° C., it is supplied to a cooling device to prevent oxidation. After being cooled to the extent, it is supplied to a separation device maintained at atmospheric pressure or lower so as to be separated into combustible components and non-combustible components. This cooling device is subjected to indirect cooling such as spraying cooling water on the outer wall surface of the drum containing the pyrolysis residue.
[0004]
[Problems to be solved by the invention]
By the way, in the cooling method of the pyrolysis residue in the waste treatment apparatus as described above, the cooling efficiency is poor because it is indirect cooling such that water is applied to the outside of the rotating drum, so that the apparatus becomes large. There's a problem.
Of course, in order to increase the cooling efficiency, there is a method of injecting or spraying cooling water directly into the pyrolysis residue, but in this case, the pyrolysis residue powder is combined into a dumpling, and the inner wall of the cooling device The cooling efficiency is deteriorated. Or it will have a bad influence on the separation efficiency in the separation device arranged on the downstream side.
[0005]
[Means for Solving the Problems]
The present invention has been made to solve the conventional problems as described above, and heats and decomposes waste to produce dry distillation gas and a pyrolysis residue mainly composed of nonvolatile components. A pyrolysis reactor; a discharge device for separating and discharging the dry distillation gas and the pyrolysis residue; a cooling device for cooling the pyrolysis residue discharged from the discharge device; and the cooled pyrolysis residue A separation device that separates a combustible component into a non-combustible component, a combustion melting furnace that generates dry slag and combustion exhaust gas by burning dry distillation gas from the discharge device and combustible component from the separation device, and A wet ash is produced by a wet ash production device for producing wet ash by adding moisture to the ash, and the wet ash is mixed with the pyrolysis residue discharged from the discharge device. To supply to the cooling device after There is provided St. cooling method of the pyrolysis residues in waste treatment apparatus characterized by a.
[0006]
The ash used in the method for cooling the pyrolysis residue in this waste treatment apparatus may be combustion ash produced by other incineration facilities, etc., but preferably the combustion ash generated in this waste treatment apparatus Is used.
That is, most of the combustion ash generated in the combustion melting furnace is melted to form molten slag, but a part of the combustion ash accompanies the combustion exhaust gas and is discharged as fly ash. It is preferable to collect the fly ash with a dust collector, add moisture to the collected ash to form wet ash, and mix the wet ash into the pyrolysis residue. In practice, since the inside of the cooling device is maintained in a low oxygen atmosphere, the wet ash is preferably mixed into the pyrolysis residue through a sealing mechanism so as not to impair this.
[0007]
According to the cooling method of the pyrolysis residue in such a waste treatment apparatus, a high-temperature dry distillation gas and pyrolysis residue of about 450 ° C. are discharged from the pyrolysis reactor into the discharge device, where The separated pyrolysis residue is separately mixed with wet ash produced by adding water to the ash, and the pyrolysis residue mixed with the wet ash is supplied into a cooling device and cooled. At this time, the moisture contained in the wet ash evaporates, and the cooling is promoted by the latent heat of vaporization at this time. As a result, the cooling device can be downsized.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a method for cooling a thermal decomposition residue in a waste treatment apparatus according to the present invention will be described with reference to FIGS.
FIG. 1 is a system diagram of a waste treatment apparatus using the method for cooling a pyrolysis residue according to the present invention.
[0009]
In FIG. 1, reference numeral 1 denotes a waste supply apparatus that supplies waste a containing combustibles such as municipal waste into the thermal decomposition reactor 2. The pyrolysis reactor 2 is usually a horizontal rotary drum, and the interior thereof is maintained in a low oxygen atmosphere by a sealing mechanism (not shown), and a heat exchanger (see FIG. heated air b which has been heated by Shimese not) is supplied from the line L _1, this heated air b inside the 300 ° to 600 °, which is usually heated to about 450 ° C..
[0010]
The waste a supplied from the waste supply apparatus 1 is pyrolyzed in the pyrolysis reactor 2 to produce a dry distillation gas G ₁ and mainly a non-volatile pyrolysis residue c.
The dry distillation gas G ₁ and the thermal decomposition residue c generated in the pyrolysis reactor 2 are separated in the discharge device 3, and the dry distillation gas G ₁ is supplied to the burner 5 of the combustion melting furnace 4 via the line L _2. Is done.
[0011]
On the other hand, the pyrolysis residue c discharged from the pyrolysis reactor 2 is supplied to the cooling device 6 and cooled. More specifically, the cooling device 6 has a generally cylindrical body 9 having spiral fins 8 as raking blades inside as shown in FIGS. 2 and 3. An inlet chute 11 connected to the discharge device 3 (FIG. 1) at one end and having a double gate valve 10 as a seal mechanism, and connected to a separation device 7 at the other end and a double gate valve as a seal mechanism An exit chute 13 having 12 is provided.
[0012]
The body 9 is rotatably supported by rotating rollers 14 and 15, and rotates when a driving force of a driving machine (for example, a motor) 16 (FIG. 3) is transmitted through the chain 17. Further, a planting member 18 is erected on the side of the body 9, and a plurality of nozzles 19 are arranged on the planting member 18 at predetermined intervals along the longitudinal direction of the body 9. All of these nozzles 19 are connected to the cooling water line L ₄ , and the cooling water W _{1 in the} water tank 20 is pressurized by the pump 21 and is ejected from the nozzle 19 to the outer surface of the body 9.
[0013]
Further, a part of exhaust gas G ₂ to be described later is supplied as inert gas from the line L ₃ (FIGS. 1 and 2) into the body 9, a low oxygen atmosphere is formed inside, and wet ash d is formed in the inlet chute 11. Is supplied from a line L ₅ through a double gate valve 23 as a sealing mechanism, and the wet ash d is mixed into the pyrolysis residue c passing through the inlet chute 11.
[0014]
The mixing ratio of the wet ash d into the thermal decomposition residue c is not particularly limited, but usually the wet ash d and the thermal decomposition residue c are in the range of 1: 3 to 1: 5. It is good to be mixed. The wet ash d is manufactured by supplying a part of the fly ash e collected by the dust collector 24 described later to the wet ash producing device 25 from the line L ₆ .
As shown in FIG. 4, for example, the wet ash production apparatus includes a body 26, a water supply pipe 30 having a stirring blade 28 and a spray nozzle 29 attached to a rotating shaft 27 disposed in the body 26, and a motor. The fly ash e constituted by the drive unit 31 and supplied into the body 26 from the line L ₆ is agitated by the agitating blade 28 and sprayed with water W ₂ to produce wet ash d.
[0015]
Of course, the wet ash d is not limited to the fly ash e, and ash generated in another incinerator or the like may be used as necessary. The pyrolysis residue c is 80 in the cooling device 6 due to the latent heat of evaporation of moisture contained in the wet ash d and the cooling water W ₁ supplied from the cooling water line L ₄ and ejected to the outer surface of the body 9. Then, the cooled pyrolysis residue c is supplied to the separator 7, where a combustible component f mainly composed of carbon and ash, and an incombustible component g such as metal or debris. The non-combustible component g is recovered in the container 33.
[0016]
The combustible component f is ground, for example, 1mm or less of the pulverized by a pulverizer 34, the pulverized combustible component f 'is supplied from the line L ₇ to the burner 5 of the combustion melting furnace 4, where the line L ₂ It is burned in a high temperature range of about 1,300 ° C. by the supplied dry distillation gas G ₁ and the combustion air h supplied from the line L ₈ by the forced blower 35. Most of the ash produced by the combustion and the ash contained in the combustible component f ′ is melted to form molten slag k, which flows into the water tank 36 and is cooled and solidified.
[0017]
The combustion ash and a part of the ash are accompanied by the combustion exhaust gas G ₃ and sent to the downstream side. The combustion exhaust gas G ₃ is recovered by the waste heat boiler 37 or an air heater (not shown) through the line L _9, and then removed by the dust collector 24 and further cleaned by the gas cleaning device 38. Most of the exhaust gas G ₂ is discharged from the chimney 39 to the atmosphere, but a part thereof is supplied into the body 9 of the cooling device 6 as an inert gas from the line L ₃ as described above. Note that 40 is an induction blower provided at the final stage of the exhaust gas G ₂ discharge path, and 41 is a power generation device that generates electric power from the steam S generated by the waste heat boiler 37.
[0018]
FIG. 5 shows another embodiment of the inlet portion of the cooling device 6. The pyrolysis residue c separated by the discharge device 3 is supplied to a screw feeder 42 and is driven by a driving device 43 such as a motor. By operating the screw feeder 42, the pyrolysis residue c is supplied into the body 9 of the cooling device 6 while maintaining the seal. Of course, in this embodiment, the wet ash d is mixed into the pyrolysis residue c through the seal mechanism 23.
[0019]
【The invention's effect】
As is clear from the above description, according to the method for cooling a thermal decomposition residue in the waste treatment apparatus according to the present invention, wet ash is mixed in the thermal decomposition residue and supplied into the cooling apparatus. Cooling is performed by using the latent heat of vaporization of the moisture in the wet ash, and as a result, the cooling device can be reduced in size.
[Brief description of the drawings]
FIG. 1 is a system diagram of an apparatus for carrying out a method for cooling a thermal decomposition residue in a waste treatment apparatus of the present invention.
FIG. 2 is a side sectional view of a cooling device.
FIG. 3 is a view taken along arrow AA in FIG. 2;
FIG. 4 is a side view of the wet ash production apparatus.
FIG. 5 is a side view of an inlet of another embodiment of the cooling device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Waste supply device 2 Pyrolysis reactor 3 Discharge device 4 Combustion melting furnace 5 Burner 6 Cooling device 7 Separation device 8 Spiral fins 9, 26 Fuselage 10, 12, 23 Double gate valve 11 Inlet chute 13 Outlet chute 14, 15 Support roller 16, 31, 43 Drive machine 17 Chain 18 Planting member 19 Nozzle 20, 36 Water tank 21 Pump 24 Dust collector 25 Wet ash production apparatus 27 Rotating shaft 28 Stirring blade 29 Spray nozzle 30 Water supply pipe 33 Container 34 Crusher 35 Intrusion blower 37 Waste heat boiler 38 Gas cleaning device 39 Chimney 40 Induction blower 41 Power generation device 42 Screw feeder

Claims (3)

A pyrolysis reactor for heating and decomposing waste to produce pyrolysis gas and a pyrolysis residue mainly composed of nonvolatile components, and a discharge device for separating and discharging the dry distillation gas and pyrolysis residue A cooling device for cooling the pyrolysis residue discharged from the discharge device, a separation device for separating the cooled pyrolysis residue into a combustible component and a non-combustible component, and dry distillation from the discharge device Wet ash for producing wet ash by adding moisture to ash in a waste treatment apparatus comprising a combustion melting furnace for generating molten slag and combustion exhaust gas by burning gas and combustible components from the separation device The wet heat ash is produced by the production device, and the wet ash is mixed with the pyrolysis residue discharged from the discharge device, and then supplied to the cooling device. Cooling method of decomposition residue. The ash generated in the combustion melting furnace dust collector with the dust collector, waste treatment according to claim 1 wherein as the addition of moisture by the Shimehai manufacturing apparatus dust collection has been incineration ash in the dust collector Method for cooling thermal decomposition residue in the apparatus. The method for cooling a pyrolysis residue in a waste treatment apparatus according to claim 1 or 2, wherein wet ash is supplied to the cooling device via a seal mechanism.

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