JP2002081623A - Pyrolytic gasification melting furnace for waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a small sized pyrolytic gasification melting furnace for waste, in which an operation control is easy, troubles in operation caused by tar and ash content are precluded, and harmful substances are not generated. SOLUTION: This furnace is equipped with a pyrolysis section for heating waste under a reductive atmosphere, a combustion section for burning a combustible gas generated by pyrolysis, and a melting section for melting residual solids in an integral furnace body as a continuous space. A dropping part in the pyrolysis section communicates with the top of the combustion section. The combustion section is constituted as a vertically long space to conduct by gravity-dropping the residual solid matter from the pyrolysis section to the melting section. In the melting section, a furnace space is formed nearly horizontally having an inclined bottom surface continuing to the lower end of the combustion section. A hole for dropping melts is provided in the furnace bottom.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pyrolysis gasification and melting furnace for incinerating waste at a high temperature using a combustible gas obtained by pyrolyzing waste.

A feature of the present invention is that crushed waste is reduced and pyrolyzed by an indirect heating method to be carbonized, and is burned in a lower combustion chamber together with the carbonized material and a combustible gas obtained at the time of pyrolysis. It is to utilize as melting energy. As the furnace structure, the structure of the gasification and melting furnace is fundamentally changed by integrating the reduction-type pyrolysis furnace with its combustion furnace and melting furnace. With this structure, the amount of heat can be used with high efficiency in order to complete the melting with the self-generated heat. Further, in the conventional structure, although a closed accident rarely occurs due to the decomposition gas being cooled and becoming tar, the accident can be prevented.

[0003]

2. Description of the Related Art Conventionally, waste disposal relies on combustion and landfill. In the case of combustion using a normal incinerator, a large amount of secondary combustion air is required, and it is necessary to treat ash from the main ash remaining at the bottom of the combustion furnace and fly ash discharged on the combustion gas. is there. From the viewpoint of ensuring a safe environment, it is necessary to remove dioxins contained in combustion gas and ash. Therefore, conventionally, measures have been taken in which dioxin generated by combustion is dropped into ash and neutralized with a chemical, sealed in concrete, or immobilized with an organic compound called a chelate.

Recently, combustible organic substances such as waste plastics and wood are carbonized at a temperature of about 300 to 500 degrees Celsius (Centigrade, the same applies hereinafter) without air and burnt as combustible gases such as carbon monoxide and methane gas. Solids remaining without decomposition are subjected to a process of melting at a high temperature at which dioxin around 1400 degrees obtained by burning the combustible gas is not synthesized, and rapidly cooling with water to form slag. The incinerator to be performed is called a gasification and melting furnace.

[0005] The combustion gas in this case is produced in the same manner as in the prior art, that is, 300 to 45 in which dioxin is resynthesized.
By quenching the temperature range of 0 degrees, the emission of dioxin can be prevented. Melting, not burning,
Ash has the advantage of being able to reduce the volume, and mere combustion leaves about 10% of solids, but if it melts, voids in the ash disappear, so it can be reduced to about 30%.
Since the amount of air supplied during combustion is small, there is an advantage that the amount of combustion gas can be reduced.

[0006]

However, conventional gasification and melting furnaces are used for the treatment of household general waste, and are not widely used for the treatment of industrial waste. The reason is,
Industrial wastes are not uniform in composition and there is concern about the management of processing equipment. In particular, small-scale gasification and melting furnaces for industrial wastes have hardly been put into practical use.

[0007] Further, in the conventional gasification and melting furnace, the mainstream is that air is blown into a combustible gas generated in a pyrolysis furnace and burned rapidly like a burner, and solid matter remaining after gasification is removed. On the other hand, metal separation is performed, and the remainder is put into a melting furnace.

However, in the above-mentioned apparatus, there is a problem that tar in the gas adheres to the flow path for sending the pyrolysis gas from the pyrolysis furnace to the combustion furnace, thereby blocking the flow path. Therefore, a screw for scraping tar adhering to the flow path is provided, and there is a problem that maintenance of the apparatus is very difficult.

Accordingly, an object of the present invention is to obtain a pyrolysis gasification and melting furnace mainly for the treatment of industrial wastes, which is relatively easy to operate and manage, and which is difficult to operate due to tar and ash generated during combustion. It is an object of the present invention to provide a waste pyrolysis gasification and melting furnace which does not have a risk of generating troubles and harmful substances and which can make the apparatus relatively small.

[0010]

The pyrolysis gasification and melting furnace according to the present invention has a combustion section between an upper pyrolysis section and a lower melting section, and pyrolyzes solids by gravity. The greatest feature is that the solids are transferred to the combustion section and the melting section together with the gas, burned in the combustion section without separating solids, and further melted in the melting section below.

The pyrolysis gasification and melting furnace 1 of the present invention comprises a pyrolysis section 2 for heating a material (waste) under a reducing atmosphere;
Combustion unit 3 that burns combustible gas generated by this thermal decomposition
And a melting part 4 for melting the remaining solid matter are provided as a continuous space in an integrated furnace. The pyrolysis section 2 is located above the combustion section 3, and the combustion section 3 is located above the melting section 4. The pyrolysis section 2 includes a transfer means 22 for transferring the material in a substantially horizontal direction, a radiant heating means 24, and a fixed quantity feeder 21 for the material, and a drop port 11 for the material is provided on the opposite side of the fixed quantity feeder 21, The falling port 11 communicates with the top of the combustion section 3.

The combustion section 3 forms a vertically long furnace space for guiding the remaining solid matter from the pyrolysis section 2 to the melting section 4 by gravity drop, and a combustion air supply port 33 is formed in the furnace wall. Is provided. The melting portion 4 forms a substantially horizontal furnace space in which the bottom surface connected to the lower end of the combustion portion 3 is inclined, and has an outlet for the molten material at the bottom on the downstream side and an exhaust port for sucking the combustion gas to the side. 13 are provided. Further, a heating burner 41 is provided in the melting portion, and an auxiliary heating burner 32 is provided in the combustion portion 3 as necessary.

In the lower part of the outlet 12 of the melting part, a cooling tank 5 is provided.
0 and a discharge conveyor 51 are provided. The gas discharged from the exhaust port 13 passes through a heat exchanger 8, a cooler 6 for rapidly cooling the temperature range in which dioxin is resynthesized (usually 300 ° C. to 450 ° C.), and a dust collector 7 such as a multicyclone or a bag filter, and is then discharged to the atmosphere. Released. An exhaust fan 90 is provided in the exhaust gas passage, and actively sucks the combustion air blown into the combustion section 3 to the exhaust port 13.

In the pyrolysis gasification and melting furnace of the present invention, the material supplied by the quantitative feeder 21 is pyrolyzed by the radiant heat of the radiant heating means 24 in the pyrolysis section 2.
The pyrolyzed combustible gas and the remaining solid matter are transferred to the combustion unit 3 without being separated. In the combustion section, the combustible gas generated in the pyrolysis furnace is burned by blowing the combustion air, and the solids falling through the combustible gas are further heated.

The heating burner 41 provided in the melting section keeps the temperature of the melting section 4 at a high temperature, melts the solids dropped from the combustion section 3, and drops and discharges the solids from the discharge port 12. In the combustion section 3, the combustible gas is not separated from the residual solids and is burned in a relatively large-area furnace space. Therefore, the combustion temperature is lower than that of the conventional pyrolysis gasification and melting furnace. The temperature is raised by the heating burner 41 provided in the above, and the solid is heated to the melting temperature. The metal contained in the remaining solid matter is separated in the melting part 4 due to the difference in specific gravity and the surface tension. By cooling this in the cooling tank 50, the metal with high purity is separated and discharged. Therefore, the metals in the slag can be separated by separating the discharged solid by gravity separation or magnetic separation.

The generation of dioxin is extremely low, the treatment of main ash and fly ash is not required, solid waste can be recycled as asphalt aggregate, etc., and metals in waste can be separated with high purity.

[0017]

FIG. 1 is a block diagram showing an embodiment of the present invention. A pyrolysis gasification and melting furnace 1 according to the invention of this application includes a pyrolysis section 2 forming a furnace space in a substantially horizontal direction, and a vertical section having a top section communicating with the pyrolysis section and a lower section communicating with the melting furnace. Combustion unit 3 that forms a space inside the furnace
And a melting part 4 having a bottom inclined and forming a substantially horizontal furnace space. The pyrolysis section 2 of the illustrated embodiment includes a fixed-quantity feeder 21 having a screw conveyor and a slightly inclined rotating drum (rotating kiln) 22.
And a heating pipe 24 formed by arranging a pipe for passing the combustion gas of the heating furnace 23 in the furnace space. The waste put into the thermal decomposition section 2 by the fixed amount feeder 21 is transferred to the anti-feeder side while being stirred with the rotation of the inclined rotating drum 22, and is heated by radiant heat from the heating pipe 24 during that time. Reflux under reducing atmosphere. The flammable gas generated by the reflux flows downward from the drop port 11 provided on the opposite bottom of the fixed-quantity feeder 21 and flows into the combustion unit 3. Also, the rotating drum 22
The remaining solids transferred to the drop port 11 side by the rotation of also fall into the combustion part 3 by gravity drop. Note that the combustion gas of the heating furnace 23 that has passed through the heating pipe 24 joins the exhaust gas of the pyrolysis gasification and melting furnace, and is discharged to the atmosphere through the desuperheater 6 and the dust collector 7. Although heavy oil is used as the fuel for the heating furnace 23, the exhaust gas of the pyrolysis gasification and melting furnace 1 can be supplied to the heating pipe 24.

A large number of combustion air supply ports 33 are provided in the furnace wall of the combustion section 3, and the exhaust of a combustion air fan 31 is heated by a heat exchanger 8 and blown. An auxiliary heating burner 32 is provided above the combustion unit 3 to ignite the combustible gas and burn with the combustion air blown from the furnace wall. The solids falling by weight in the combustion section are heated by the combustion and guided to the melting section 4 below the combustion section.
In the melting part 4, the solid matter that has fallen is further heated and melted by the heating burner 41, flows downstream according to the inclination of the bottom surface, and the solid matter that has passed the weir 42 falls from the outlet 12 into the cooling tank 50. I do. The molten solid is separated into metal and ash by specific gravity and surface tension, and the metals are separated by the difference in specific gravity and fall into the cooling tank 50.
Metal can be separated with high accuracy. In the cooling tank of the illustrated embodiment, water cooling is performed, slag is crushed by rapid cooling, and is transported to the slag reservoir 52 by the discharge conveyor 51. When separating the separated metals, a gravity separator or a magnetic separator is arranged between the discharge conveyor 51 and the slag reservoir 52.

An exhaust port 13 is opened to the side of the exhaust port 12, and this exhaust port is set to a negative pressure by an exhaust fan 90, and the combustion section 3 actively promotes the combustion air blown into the furnace. It is sucking. This active suction and pyrolysis unit 2
The combustion air in the combustion section is converted by the gas generated in
Flow is stopped. The high-temperature gas flowing out of the exhaust port 13 is used to heat the combustion air in the heat exchanger 8, then joins with the exhaust gas of the heating furnace described above, passes through the desuperheater 6 and the dust collector 7, and passes through the chimney. Released to the atmosphere from 91.

The cooler 6 (also called a gas cooler)
The re-synthesis temperature range of dioxin is rapidly cooled by the spray water sprayed into the gas passage. The dust collector 7 is a multicyclone, a bag filter, or the like. The large ash in the exhaust gas is captured by the spray water in the desuperheater 6 and separated by gravity. Fine particles are separated in the dust collector 7. Almost no fly ash is generated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of an embodiment.

[Explanation of symbols]

 2 Thermal decomposition section 3 Combustion section 4 Melting section 11 Drop port 13 Exhaust port 24 Heating pipe 33 Air supply port 41 Heating burner 42 Weir

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F23G 5/16 ZAB F23J 1/08 F23J 1/08 F27B 1/08 Z F27B 1/08 1/10 1 / 10 B09B 3/00 303K (72) Inventor Mei Mei 7 in Kannon-do-cho, Kanazawa-shi, Ishikawa Prefecture Inside (72) Inventor Hidehide Kinoshita 7 in Kannon-do-cho, Kanazawa-shi, Ishikawa Prefecture (Actly Murata in ( 72) Inventor Kenji Ikeda 7 Kannondo-cho, Kanazawa-shi, Ishikawa F-term in Actley Murata Co., Ltd. 3K078 BA03 BA22 BA26 CA03 CA09 CA12 CA21 CA24 CA25 4D004 AA01 AC04 CA24 CA29 CA32 CB09 CB36 CB42 4K045 AA01 BA10 CA02 GA02 GB08 GD01

Claims (4)

[Claims] 1. A combustion section is provided between an upper thermal decomposition section and a lower melting section, and residual solids in the thermal decomposition section are transferred to the combustion section and the melting section together with the pyrolysis gas by gravity drop by thermal decomposition. A pyrolysis gasification and melting furnace, characterized in that gas and solid matter are burned in a combustion part without being separated, and solid matter that has passed through the combustion part is melted in a melting part below the combustion part. 2. A pyrolysis section (2) for heating a material in a reducing atmosphere, a combustion section (3) for burning a combustible gas generated in the pyrolysis section, and a melting section for melting the remaining solid matter. (4) is provided as a continuous space in the integral furnace body, the pyrolysis section (2) is located above the combustion section (3), and the combustion section (3) is located above the melting section (4). The pyrolysis section (2) includes a radiant heating means (24) and a material drop port (11) communicating with the top of the combustion section (3),
The combustion part (3) is provided with a supply port (33) for combustion air, and the melting part (4) is provided at the bottom with a drop for molten material and an exhaust port for sucking combustion gas
(13) A pyrolysis gasification / melting furnace comprising: The pyrolysis section (2) forms a substantially horizontal furnace space provided with a transfer means (22) for transferring the material in a substantially horizontal direction, and the combustion section (3) is heated by gravity. A vertically long furnace space is formed to guide the remaining solid matter from the decomposition part (2) to the melting part (4), and the melting part (4) forms a substantially horizontal furnace space with a slanted bottom. 3. The pyrolysis gasification and melting furnace according to claim 2, wherein A melting part (4) has a heating burner (41) for maintaining the temperature of the solid material at a high temperature and a weir (4) for restricting the flow of molten slag.
4. The pyrolysis gasification and melting furnace according to claim 3, further comprising (2).