JPH102526A - Pyrolysis reactor in waste treatment equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent formation of a coating layer due to deposit to a heating tube of a pyrolysis reactor by introducing waste into the reactor via a screw feeder, and disposing a heating means at the feeder. SOLUTION: A screw feeder 5 has a waste supply port 30 at one end and a casing 31 opened in a pyrolysis reactor 1 and a screw 3 mounted at a screw shaft 32 disposed in the casing 31 at the other end. The casing 31 is formed in a jacket state of double shells made of an inner cylinder 31a and an outer cylinder 31b. Part of heated air or part of steam generated by a waste heat boiler is, for example, supplied as heated fluid (k) from a line L8 between the cylinders 31a and 31b to heat the inner waste (a) to, for example, about 200 deg.C. As a heating means, a system for heating an outside of the casing 31 can be adopted in addition to the above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pyrolysis reactor in a waste treatment apparatus, and more particularly, to a method in which waste is heated in a pyrolysis reactor maintained at a sub-atmospheric pressure and a low oxygen atmosphere. Pyrolysis in a steamed state to produce a carbonized gas and a pyrolysis residue, and supply the carbonized gas and a combustible component separated from the pyrolysis residue to a combustor for combustion treatment. The present invention relates to a thermal decomposition reactor in a waste treatment apparatus.

[0002]

2. Description of the Related Art As one of the waste disposal devices including general waste such as municipal waste and combustible materials such as waste plastic,
The waste is put into a pyrolysis reactor and heated in a low-oxygen atmosphere at atmospheric pressure or lower and pyrolyzed in a steamed state, producing dry distillation gas and pyrolysis residues mainly of non-volatile components. After cooling the material, it is supplied to a separator to separate the combustible component mainly composed of carbon and the non-combustible component consisting of rubble such as metal, pottery, gravel, concrete pieces, etc., and crush the combustible component. Then, the pulverized combustible component and the above-mentioned dry distillation gas are led to a melting furnace which is a combustor, subjected to combustion treatment in the melting furnace, and the resulting combustion ash and ash contained in the combustible component. A waste treatment apparatus in which molten slag is discharged and cooled and solidified is proposed in, for example, JP-A-64-49816.

[0003] As a thermal decomposition reactor in such a waste disposal apparatus, a horizontal rotary drum usually equipped with a heating tube serving as a heat transfer surface for indirect heating is used, and is put into the horizontal rotary drum. The waste is heated at 300 ° C. to 60 ° C. by the heating fluid supplied into the heating pipe, mainly heated air.
It is heated to 0 ° C., usually to about 450 ° C., and thermally decomposed.

[0004]

As described above, in a horizontal rotary drum having a heating tube therein, an adhesion layer is formed on the outer surface of the heating tube, and since the adhesion layer is heat insulating, the heat conductivity is low. However, there is a problem that the thermal decomposition efficiency gradually decreases. That is, in such a horizontal rotary drum, 2
In a process in which waste at about 0 ° C. is introduced into the drum main body from the supply port, and is transferred while rolling to the discharge port side at the other end, a heating fluid such as heated air supplied from the discharge port side into the heating pipe. 450 ° C. in a so-called countercurrent method
It is thermally decomposed by being heated to a certain degree, and becomes a pyrolysis product composed of the carbonized gas and the pyrolysis residue, and is discharged from the outlet.

However, recent wastes contain relatively large amounts of synthetic resin products such as molded products such as plastic films and bottles. This synthetic resin melts at about 200 ° C. in a pyrolysis process, and , The thermal conductivity is reduced. In order to improve such a problem, it is conceivable to increase the temperature of the heating fluid supplied into the heating pipe and increase the temperature of the waste input side. In this case, the temperature of the heating fluid is increased. Therefore, heat energy is required, and there is a problem that a means for supplying heat must be added.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and is directed to a pyrolysis reactor in which waste is kept under atmospheric pressure. Throwing in, heating the waste to generate a pyrolysis product consisting of a pyrolysis gas and a pyrolysis residue of mainly non-volatile components, separating the pyrolysis residue into a combustible component and a non-combustible component, In a waste treatment apparatus configured to burn the carbonized gas and the combustible component, the pyrolysis reactor is constituted by a horizontal rotary drum having a heating tube therein, and a screw feeder is provided in the pyrolysis reactor. The waste is charged, and the screw feeder is provided with a pyrolysis reactor in a waste treatment apparatus in which a heating means is disposed. The screw feeder includes a casing having a waste supply port at one end and an opening at the other end in the pyrolysis reactor, and a screw disposed in the casing and attached to a screw shaft. Or the casing is formed as a double shell, and the heating fluid is supplied into the double shell, or the screw shaft is formed as a double structure, and the heating is performed by supplying the heating fluid to the screw shaft. The waste supplied to the cracking reactor is heated.

[0007] In the thermal decomposition reactor in such a waste treatment apparatus, the waste is heated when passing through the screw feeder, preferably heated to about 200 ° C, and the synthetic resin mixed in the waste is removed. Melts,
It will be supplied to the pyrolysis reactor in a state of being attached to other waste. Therefore, no deposits are generated on the surface of the heating tube. At the same time, the waste is heated in advance and then supplied to the thermal decomposition reactor, so that the thermal decomposition reactor can be downsized.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a thermal decomposition reactor in a waste treatment apparatus according to the present invention will be described below with reference to FIGS. FIG. 1 is a system diagram of a waste treatment apparatus equipped with a horizontal rotary pyrolysis reactor 1 according to the present invention,
In this figure, waste a containing combustibles such as municipal solid waste a
Is supplied into the pyrolysis reactor 1 by a waste supply device 2 comprising a crane 4 having a bucket 3. The waste a is sequentially supplied from the waste supply device 2 to the pyrolysis reactor 1 via a screw feeder 5 provided at a stage preceding the pyrolysis reactor 1.

[0009] This rear portion of the pyrolysis reactor 1, heated air b which has been heated by air heater 7 disposed on the downstream of the melting furnace 6 is combustor is supplied from the line L _1, and the inside thereof It is heated to 300 ° C. to 600 ° C., usually about 450 ° C., and the interior of the waste treatment device is reduced to an atmospheric pressure and a low oxygen atmosphere by the action of the induction blower 8 provided at the latter stage of the waste treatment device. It is configured.

The waste a is heated and thermally decomposed while moving to the outlet side while rolling in the decomposition reactor 1 to separate the carbonized gas G ₁ and the pyrolysis residue c mainly composed of carbon. Generate. Then, the carbonized gas G ₁ and the pyrolysis residue c are separated in the discharge device 9 arranged on the outlet side of the decomposition reactor 1. Then, the carbonization gas G ₁ is supplied to the burner 10 of the melting furnace 6 through the line L ₃ .

On the other hand, the pyrolysis residue c discharged from the discharge device 9 is cooled by the cooling device 11 to a temperature at which there is no danger of ignition, for example, about 80 ° C. d and non-combustible components e composed of rubble, such as metal and ceramics. The non-combustible component e is collected in the container 14,
The combustible component d is pulverized into fine powder of 1 mm or less by a pulverizer 15, and the pulverized combustible component d ′ is supplied to a line L _3.
The burner 10 is supplied to the burner 10 via the line L _2, and the dry distillation gas G ₁ supplied from the line L ₂ and the combustion air f supplied from the line L ₄ by the push-in blower 16 to about 1,3.
The fuel is burned at a high temperature of about 00 ° C., and the combustion ash generated during the combustion and the ash mixed in the combustible component d ′ flow down as molten slag g and are cooled and solidified in the water tank 17. The cooled and solidified slag is used as a building material such as a pavement material.

On the other hand, the combustion gas G ₂ generated in the melting furnace 6
After being heat recovery through the air heater 7 and a waste heat boiler 18 via line L _5, the dust collector is dust by 19, and purifier 20 relatively cool clean exhaust gas G ₃ is desulfurized purified by most become is released from the chimney 21 into the atmosphere, part of it is supplied to the cooling device 11 as an inert gas via line L _6.

[0013] The dust h trapped by the dust collector 19 is guided into the melting furnace 6 through line L ₇ is melted. In addition,
Reference numeral 22 denotes a power generation device that generates power using steam s generated by the waste heat boiler 18, and includes a steam turbine 23 and a generator 2.
4. As described above, the thermal decomposition reactor 1 is constituted by a horizontal rotary drum. 26, and a heated air supply header 2 provided on the outlet side of the dry matter of the heat-treated waste a.
7, a heated air discharge header 28 provided on the supply side of the waste a, and a driving device 29 such as a motor for supporting and driving the outside of the rotating drum. Further, the screw feeder 5 penetrates through the center of the heating air discharge header 28, and further the heating air supply header 2
Discharge devices 9 are provided adjacent to each other.

The present invention is characterized in that the screw feeder 5 is provided with a heating means. The heating means will be described below. As shown in FIG. At the other end, a casing 31 having an opening 30 and opening into the pyrolysis reactor 1, and a screw 33 attached to a screw shaft 32 disposed inside the casing 31 are provided.

The casing 31 has an inner cylinder 31a.
And an outer cylinder 13b, and is formed in a jacket shape of a double shell. Between the inner cylinder 31a and the outer cylinder 31b, for example, a part of the heated air b or one steam s generated by the waste heat boiler 18 is provided. part is supplied from the line L ₈ as a heating fluid k, the interior of the waste a, is to heat for example to about 200 ° C..

FIG. 4 shows another embodiment of the heating means, in which the screw shaft 32 has a double structure of a hollow inner shaft 32a and an outer shaft 32b, and the heating fluid k is an inner fluid. It is supplied between the shaft 32a and the outer shaft 32b. And this heated fluid k is adapted to be recovered inside the inner shaft 32a from the street line L ₉ at the distal end of the screw shaft 32.

Reference numeral 34 denotes a driving device for driving the screw shaft 32, and reference numeral 35 denotes a heating fluid supply / discharge header. As the heating means, various methods other than these examples are selected,
For example, a method in which the outside of the casing 31 is heated by a heater or the like may be employed.

[0018]

As is apparent from the above description, according to the thermal decomposition reactor in the waste treatment apparatus according to the present invention,
A heating means is provided in the screw feeder attached to the pyrolysis reactor, and the waste to be pumped by the screw is preliminarily heated and charged into the pyrolysis reactor. The formation of the coating layer can be prevented, and as a result, a decrease in the thermal conductivity of the heating tube can be prevented, and in addition, the size of the thermal decomposition reactor can be reduced.

[Brief description of the drawings]

FIG. 1 is a system diagram of a waste treatment apparatus equipped with a pyrolysis reactor according to the present invention.

FIG. 2 is a side view showing a pyrolysis reactor partially broken away.

FIG. 3 is a side sectional view of a screw feeder.

FIG. 4 is a side sectional view of another embodiment of the screw feeder.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pyrolysis reactor 2 Waste supply device 3 Bucket 4 Crane 5 Screw feeder 6 Melting furnace 7 Air heater 8 Induction blower 9 Discharge device 10 Burner 11 Cooling device 12 Separator 14 Container 15 Crusher 16 Push-in blower 17 Water tank 18 Waste Heat boiler 19 Dust collection device 20 Purification device 21 Chimney 22 Power generation device 23 Steam turbine 24 Generator 25 Heating tube 26 Drum main body 27 Heated air supply header 28 Heated air discharge header 29, 34 Drive device 30 Waste supply port 31 Casing 32 Screw Shaft 33 Screw 35 Heated fluid supply / discharge header

Claims (4)

[Claims] 1. A waste introduced into a pyrolysis reactor whose inside is kept in a low oxygen atmosphere at atmospheric pressure or lower is heated and thermally decomposed to form a carbonized gas and a pyrolysis residue mainly composed of nonvolatile components. A pyrolysis product comprising: separating the pyrolysis residue into a combustible component and a non-combustible component; and performing a combustion treatment on the dry distillation gas and the combustible component. The thermal decomposition reactor is constituted by a horizontal rotary drum having a heating tube therein, and waste is supplied into the thermal decomposition reactor by a screw feeder, and a heating means is arranged in the screw feeder. Pyrolysis reactor in waste treatment equipment. 2. A screw feeder having a waste supply port at one end and a casing open at the other end into a pyrolysis reactor, and a screw disposed in the casing and attached to a screw shaft. 2. The thermal decomposition reactor in a waste treatment apparatus according to claim 1, wherein the casing is formed as a double shell, and a heating fluid is supplied into the double shell. 3. A screw feeder comprising a casing having a waste supply port at one end and an open end in the pyrolysis reactor at the other end, and a screw arranged in the casing and attached to a screw shaft. 3. A thermal decomposition reactor in a waste treatment apparatus according to claim 1, wherein said screw shaft has a double structure, and a heating fluid is supplied to said screw shaft. 4. A screw feeder comprising a casing having a waste supply port at one end and an open end in the pyrolysis reactor at the other end, and a screw disposed in the casing and attached to a screw shaft. The thermal decomposition reactor in a waste treatment device according to claim 1 or 2, wherein a heater is wound around the casing.