JPH109535A - Thermal decomposition reactor in waste disposal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a coating layer having low heat conductivity from being formed on the surface of a heating tube on the feed side of waste by constituting a thermal cracking reactor of a horizontal rotary drum including therein a heating tube and providing a heat transfer accelerating material in the heating tube on the waste feed side. SOLUTION: The thermal decomposition reactor is of the horizontal rotary drum type and comprises a drum body 26 including therein a plurality of heating tubes 25, a heated air feed header 27 connected to the rear end of the body 26, a heated air discharge header 28 connected to the front end of the body 26, and a horizontal rotary drum drive device 29. And a plurality of fins 31 functioning as heat transfer accelerating materials are provided in the tube 25 on the waste feed side thereof so as to be oriented toward the center of the tube, in the longitudinal direction. As a result, a fall in surface temperature of the tube 25 on the waste inlet side can be suppressed and hence formation of a surface coating layer consisting of a substance having a low heat conductivity such as synthetic resin can be prevented, thus the reactor can have improved thermal efficiency.

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 pyrolysis of waste by heating it in a low oxygen atmosphere at a pressure lower than the atmospheric pressure, to obtain a carbonized gas and a pyrolysis residue. The present invention relates to a pyrolysis reactor in a waste treatment apparatus in which a waste product is generated and the dry distillation gas and a combustible component separated from the pyrolysis residue are burned in a combustor.

[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 fed to a pyrolysis reactor and pyrolyzed by heating to a high temperature in a low oxygen atmosphere below atmospheric pressure to produce a dry distillation gas and a pyrolysis residue mainly composed of non-volatile components. After cooling the residue, it is fed to a separator,
The combustible component mainly composed of carbon and, for example, metal and pottery, gravel, separated into non-combustible components composed of rubble such as concrete pieces, pulverized the combustible component, the pulverized combustible component and the The carbonization gas is burned in a melting furnace as a combustor, and the resulting combustion ash and the ash contained in the combustible components are converted into molten slag, and the molten slag is discharged and solidified by cooling. A waste disposal apparatus has been proposed in, for example, Japanese Patent Application Laid-Open No. 64-49816.

[0003] As a thermal decomposition reactor in such a waste treatment apparatus, a horizontal rotary drum usually equipped with a heating tube serving as a heat transfer surface for indirect heating is used, and the waste put into the horizontal rotary drum is used. Is heated to 300 ° C. to 600 ° C., usually about 450 ° C. by a heating fluid supplied into the heating tube, and is thermally decomposed.

[0004]

In the case of the horizontal rotary drum having the above-described heating tube, a kind of coating layer composed of a deposit of molten plus racks in the waste material is formed on the outer surface of the heating tube, and the heating layer is heated. There is a problem that the decomposition efficiency is reduced.
That is, in the horizontal rotating drum having the above-described structure, the temperature is 20 ° C.
In the process in which the waste is introduced into the drum body from the supply port and is rolled and transferred to the discharge port side at the other end, the waste is heated by the heating fluid supplied from the discharge port side into the heating pipe.
It is thermally decomposed by receiving heat in a so-called countercurrent method, and is pyrolyzed as a pyrolysis product composed of a dry distillation gas at about 450 ° C. and a pyrolysis residue, and is discharged from the outlet.

However, recent waste contains a relatively large amount of synthetic resin such as molded products such as plastic films and bottles.
It melts at about 00 ° C., forms a kind of coating layer, and lowers thermal conductivity. In order to solve the above problem, it is considered that the temperature of the heating fluid supplied into the heating tube is further increased, and the temperature of the waste inlet is increased so that the molten synthetic resin does not adhere to the heating tube. However, in this case, there is a problem that heat energy for raising the temperature of the heating fluid is required.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the conventional apparatus, in which waste is charged into a pyrolysis reactor, and the waste is heated. To generate a pyrolysis product consisting of a pyrolysis gas and a pyrolysis residue mainly composed of non-volatile components. The pyrolysis residue is separated into a combustible component and a non-combustible component. In a waste treatment apparatus configured to combust a gas and the combustible component, the thermal decomposition reactor is constituted by a horizontal rotary drum having a heating tube therein, and a heat transfer side is provided to a waste input side in the heating tube. An object of the present invention is to provide a pyrolysis reactor in a waste treatment device, which is provided with an accelerator.

[0007] The heat transfer enhancer is composed of a fin or a spiral member twisted in a longitudinal spiral shape. In the case of a fin, a spiral fin is preferably used. According to the pyrolysis reactor in the waste treatment apparatus configured as described above, the heating pipe is heated by the heating fluid supplied into the heating pipe from the discharge port side of the pyrolysis product, and the surface temperature of the heating pipe is reduced. The temperature gradually decreases toward the charging side. In this case, since the turbulence is given to the heating fluid by the action of the heat transfer enhancer, the degree of the temperature reduction is small, and therefore, the synthetic resin adhered to the heating pipe surface on the charging side. Is gasified without carbonization, so that the formation of a coating layer by deposits can be prevented.

[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 pyrolysis reactor 1 according to the present invention. In the figure, reference numeral 2 denotes a waste a containing flammable materials such as municipal solid waste in the pyrolysis reactor 1. The waste supply device 2 is composed of a waste supply device 2 and a crane 4 having a bucket 3. The waste a is supplied to the screw feeder 5 by the waste supply device 2 while measuring the supply amount. It is supplied to the thermal decomposition reactor 1.

Heating air b heated by an air heater 7 disposed downstream of a melting furnace 6 as a combustor is supplied to the pyrolysis reactor ₁ from a line L ₁ , and the inside thereof is about 300 mm. C. to 600.degree. C., usually about 450.degree. C., and the induction blower 8 disposed at the last stage of this waste treatment apparatus does not leak gas and odor to the outside, and also removes the waste a. The interior is kept below atmospheric pressure so as not to ignite.

The waste a heated in such a pyrolysis reactor 1 is thermally decomposed in a steamed state to produce a carbonization gas G ₁ ,
It becomes a pyrolysis residue c mainly composed of carbon, is separated in the discharge device 9, and the carbonization gas G ₁ is supplied from the line L ₂ to the burner 10 of the melting furnace 6. On the other hand, the pyrolysis residue c is cooled by the cooling device 11 to a temperature at which there is no risk of ignition, for example, about 80 ° C., and then, in the separation device 12, the combustible component d such as carbon and the rubble material such as metal and ceramics are removed. And the non-combustible component e.

The non-combustible component e is collected in a container 14, while the combustible component d is collected by a crusher 15 for 1 mm.
It is crushed into the following fine powder. The ground combustible component d 'is supplied to the burner 10 via line L _3, wherein the carbonization gas G ₁ supplied from the line L _2, for combustion supplied from the line L ₄ by forced draft fan 16 Air f
As a result, the fuel is burned at a high temperature of about 1,300 ° 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 flow down in the water tank 17. Cooled and solidified. 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
An air heater 7 via a line L _5, after being heat-recovered by the waste heat boiler 18, the dust collector 19 is dust, and is desulfurized purified by purification device 20, a clean exhaust gas G ₃ relatively cool become largely released from the chimney 21 into the atmosphere, some of which are supplied as inert gas to the cooling device 11 via the line L _6, cooling the pyrolysis residue c. Further, dust h trapped by the dust collecting device 19 is guided to the melting furnace 6 through line L ₇ so as to be melted. Reference numeral 22 denotes a power generation device that generates power by the steam s generated by the waste heat boiler 18, and includes a steam turbine 23 and a power generator 24.

The thermal decomposition reactor 1 is a horizontal rotary drum. The thermal decomposition reactor 1 includes a drum main body 26 having a plurality of heating tubes 25 therein, as shown in FIGS. And a heated air discharge header 28 connected to the front end.
And a drive device 29 such as a motor for driving the horizontal rotary drum.

Heating tube 2 in the pyrolysis reactor 1 according to the present invention
In 5, a heat transfer enhancer is provided. That is, as shown in FIG. 4 and FIG. 5, a plurality of fins 31 as heat transfer promoters are provided in Mounted in the longitudinal direction. The fin 31 does not need to be provided over the entire length L of the heating tube 25, and at least the length L of the heating tube 25 is within a range of La from the center in the longitudinal direction toward the waste inlet.
Is preferably set in the range of 0.1 to 0.5. The fins 31 may be linear, but are preferably formed in a spiral shape.

FIG. 6 shows another embodiment of the heat transfer enhancer.
An elongated strip-shaped metal plate is bent in the longitudinal direction to form a spiral member 32, and the spiral member 32 is inserted into the heating tube 25 on the waste inlet side. Of course,
The heat transfer enhancer is not limited to these, and any other shape may be used as long as it imparts a turbulent effect to the heat fluid a flowing through the heating pipe 25.

In the thermal decomposition reactor 1 of such a waste treatment apparatus, the degree of the surface temperature t ° of the heating pipe 25 decreases less at the waste inlet as shown in FIG. Then, the surface temperature t ° of the heating tube 25 near the waste inlet side is set in advance so as to be higher than the melting temperature Δt ° of the synthetic resin, and the temperature and the supply amount of the heated air b are controlled.

[0017]

As is apparent from the above description, according to the thermal decomposition reactor in the waste treatment apparatus according to the present invention,
The thermal decomposition reactor was composed of a horizontal rotating drum with a heating tube inside, and the heat transfer promoting body was placed inside the heating tube and on the waste inlet side, so the surface temperature of the heating tube on the waste inlet side The fall can be suppressed, and as a result, the formation of a surface coating layer made of a poor conductor of heat by synthetic resin or the like can be prevented. Therefore, there is an effect that a thermal decomposition reactor having good thermal efficiency can be obtained.

[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 part of the thermal decomposition reactor in a cutaway manner.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a side view in which a part of a heating tube on a side of a waste inlet is cut away.

FIG. 5 is a sectional view taken along line BB in FIG. 4;

FIG. 6 is a partially cutaway side view of a heating tube side of a heating tube according to another embodiment.

FIG. 7 is a diagram showing a surface temperature of a heating tube.

[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 Separation device 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 Drive device 30 Tube plate 31 Fin 32 Spiral member

Claims (4)

[Claims] Claims: 1. Waste is introduced into a pyrolysis reactor, and the waste is heated and pyrolyzed to generate a pyrolysis product consisting of a dry distillation gas and a pyrolysis residue mainly composed of nonvolatile components.
In a waste treatment apparatus configured to separate the pyrolysis residue into a combustible component and a non-combustible component and burn the carbonized gas and the combustible component, a heating pipe may be provided for the pyrolysis reactor. A thermal decomposition reactor in a waste treatment apparatus, comprising a horizontal rotating drum to be installed, and a heat transfer enhancer provided on a waste input side in the heating tube. 2. The thermal decomposition reactor according to claim 1, wherein the heat transfer enhancer attached to the inner wall of the heating pipe comprises fins. 3. The thermal decomposition reactor according to claim 1, wherein the heat transfer enhancer attached to the inner wall of the heating pipe comprises a spiral fin. 4. The thermal decomposition reactor according to claim 1, wherein the heat transfer enhancer attached to the inner wall of the heating pipe comprises a spiral member which is spirally bent in a longitudinal direction.