JPH10238728A - Heat treatment facility for waste and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat treatment facility for waste to reduce an energy necessary for the operation and further provide a heat treatment method therefore. SOLUTION: A waste-heat-treatment facility includes a thermal decomposition furnace 4 which transfers and carrier out a dry distillation on a waste A and extends in a longitudinal direction 6. The thermal decomposition furnace 4 is provided with an entrance portion 10 at one end thereof and an exit portion 14 at an opposite end thereof for a thermally decomposed residue R which is produced at the time of dry distillation. An outlet 24 for a processed gas SG produced in the thermal decomposition furnace 4 is provided at the exit portion 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus and a method for heat treating waste.

[0002]

2. Description of the Related Art In the field of heat treatment of waste, a dry distillation combustion method is known. Equipment operating in this manner is described, for example, in EP-A-030310 or in the company report published by Siemens AG in 1996, entitled "Distillation Combustion Method, Instruction Manual (Die Schwel-Brenn-Anlage, eine Ver.
fahrensbeschreibung) ". The carbonization combustion method mainly consists of two stages. The waste or refuse supplied in the first stage is placed in a carbonization chamber or a heating chamber (pyrolysis furnace) and carbonized, that is, heat-treated at a temperature of 300 to 600 ° C. in an oxygen-poor atmosphere. This heat treatment produces process gases and pyrolysis residues in the carbonization chamber. The pyrolysis residue consists of combustible and non-combustible parts. Useful materials in non-combustible parts, such as metals and glass, are sorted and sent almost completely to a later recycling process. In the second stage of the carbonization combustion process, the flammable pyrolysis residue is combined with the process gas in a hot combustion chamber at about 1200 ° C.
Burned at a temperature of

A known pyrolysis furnace is a cylindrical heating chamber that extends in the longitudinal direction and rotates about its longitudinal axis at, for example, 2 to 4 rpm. The heating chamber is inclined with respect to the horizontal in its longitudinal direction so that its rotational movement allows waste to be transported in its longitudinal direction. Therefore, the waste is transported from the loading section to the discharging section in the pyrolysis furnace, and carbonized during the transport. The waste is put into the pyrolysis furnace at the entrance and discharged from the pyrolysis furnace at the exit.

In this known facility, the process gas generated during the pyrolysis in the pyrolysis furnace is likewise taken out of the pyrolysis furnace at the carry-out section. Therefore, the transport of the process gas and the waste in the pyrolysis furnace is performed in the same direction. As a result, relatively cool waste is present at the carry-in point, and relatively cool steam-saturated process gas is present thereon. This makes the drying process near the loading section difficult. Since the process gas discharged from the carry-out section contains water evaporated from the waste during the drying process, all the steam is first introduced into the carbonization chamber by 300-600.
It must be heated to a process temperature of ° C. This increases the energy required for drying and pyrolysis of the waste. Further, due to the high concentration of steam, the steam as an inert component is additionally heated to about 1200 ° C. without supplying energy when burning the combustible components of the process gas in the high temperature combustion chamber. The heating value of the process gas is reduced.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a waste heat treatment facility in which the energy required for the operation of the facility is reduced. It is a further object of the present invention to provide such a heat treatment method for waste.

[0006]

SUMMARY OF THE INVENTION The first object of the present invention is solved by a device according to claim 1. The waste heat treatment equipment according to the present invention has a longitudinally extending pyrolysis furnace for transporting and carbonizing the waste, the pyrolysis furnace having a waste carry-in section at one end thereof and an opposite end at the opposite end. It has a discharge section for the pyrolysis residue generated during the carbonization, and an outlet for the process gas generated in the pyrolysis furnace is arranged at the input section. By this measure, at least a part of the process gas generated in the pyrolysis furnace is guided in a direction opposite to the direction in which the waste is transported.
As a result, the waste is already effectively dried and heated at the input, since the hot drying process gas is present on the relatively cold waste at the input. Therefore, the start of the carbonization process is moved closer to the loading section. Furthermore, since at least a portion of the steam is removed at the inlet, it is not necessary to heat this steam to the process temperature in the pyrolysis furnace and subsequently in the hot combustion chamber, thus reducing the energy required for the operation of the installation. Is done.

In an advantageous embodiment of the invention, the pyrolysis furnace is connected to an oxygen-containing gas supply line opening therein. Such a supply line is known, for example, from DE-A 43 27 953 A1. By combining the present invention with this measure, the point of partial oxidation of the process gases and pyrolysis residues generated in the pyrolysis furnace is also moved to the input, where additional waste already exists in the central area of the pyrolysis furnace. The advantage of being heated to a low temperature.

It is particularly advantageous if a heat exchanger for heating the oxygen-containing gas is connected to the supply line.

In an advantageous embodiment of the invention, the screw housing of the waste screw conveyor upstream of the pyrolysis furnace is heated with the process gas at least over a part of its length. This results in the waste being preheated before entering the pyrolysis furnace.

[0010] In particular, the screw housing is arranged in a passage for guiding the process gas over at least a part of its length. In this way, the screw housing is heated all around and the heat transfer from the process gas to the waste is improved.

[0011] Preferably, the screw housing is heated, at least for part of its length, with a heating gas generated outside the pyrolysis furnace, the heating gas being provided between the passage for guiding the process gas and the screw housing. It is guided through a heating jacket arranged. This measure prevents the water vapor present in the process gas from condensing on the relatively cold surface of the screw housing.

A second object of the invention is achieved by a method according to claim 8. In the waste heat treatment method according to the present invention, the waste is put into the pyrolysis furnace extending from the loading section toward the unloading section in the longitudinal direction at the loading section, and is transported in the longitudinal direction of the pyrolysis furnace. The carbonization is performed, and at least a part of the process gas generated during the carbonization is removed from the pyrolysis furnace at the carry-out section.

[0013] Further advantageous embodiments of the invention are described in the respective dependent claims.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings.

In FIG. 1, the heat treatment equipment for the waste A has a screw conveyor 2 for transporting the waste A to a pyrolysis furnace 4 extending in the longitudinal direction 6, for example, a packed screw conveyor. In the pyrolysis furnace 4, the pyrolysis or dry distillation of the waste A is performed. The pyrolysis furnace 4 is heated for this purpose by a heating gas HG which is guided through a heating tube 8 arranged therein. The heating gas HG is generated in a combustion process (not shown) outside the pyrolysis furnace 4.

The cylindrical pyrolysis furnace 4 is inclined with respect to a horizontal line, is supported rotatably about its longitudinal axis 6, and is connected to a fixed equipment part via an airtight rotary bushing 9. The waste A is slowly conveyed from the loading section 10 of the pyrolysis furnace 4 to the discharge section 14 in the direction of the arrow 12 by the tilting and rotating motion of the pyrolysis furnace 4. The screw conveyor 2 opens into the pyrolysis furnace 4 at the loading section 10, and a chamber 16 for receiving the pyrolysis residue R is connected to the unloading section 14. The pyrolysis residue R is introduced into a downstream sorting device 18 where it is divided into a fine component F and a coarse component G. The fine component F and the process gas SG generated during the dry distillation inside the pyrolysis furnace 4 are led to a high-temperature combustion chamber (not shown), where they are burned together.

The pyrolysis furnace 4 is connected to a cylindrical passage 20 at a carry-in portion 10 thereof. This passage 20 surrounds the screw housing 22 of the screw conveyor 2 at least over part of its length. This passage 20
Opens into an exhaust chamber 24 from which the process gas SG is exhausted by, for example, an induced blower (not shown). The cylindrical passage 20 and the exhaust chamber 24 form an outlet for at least a part of the process gas SG generated in the pyrolysis furnace 4 at the loading section 10. Similarly, a cylindrical heating jacket 25 is provided between the process gas guide passage 20 and the housing 22 of the screw conveyor 2. It has, for example, tubing 26, 27 (see FIG. 2) and is first passed to the right and then to the left by a partial flow of the heating gas HG generated outside the pyrolysis furnace 4. The heating jacket 25 reliably prevents water vapor in the process gas SG from condensing in the relatively cold screw housing 22.

A discharge port 28 for the process gas SG is provided in the chamber 16 disposed in the discharge section 14, and the process gas SG is discharged from the pyrolysis furnace 4 and the chamber 16 through this outlet 28.

The process gas SG respectively taken out from the carry-in side outlet 24 and the carry-out side outlet 28 is exhausted by, for example, a common induction blower. In this case, the ratio of the amount of the process gas SG taken out from the carry-out portion to the amount of the process gas SG taken out from the carry-in portion is controlled by an appropriate regulating valve or regulating flapper. However, it is also possible to provide two induction blowers that are driven independently of each other, in which case the transfer direction 12 of the waste A is controlled according to the control of the induction blowers connected to the carry-in outlet 24 and the carry-out outlet 28, respectively. In the opposite direction, the amount of the process gas flow flowing in the direction of the dashed arrow 29 is adjusted.

A supply pipe 30 for supplying a gas BG containing oxygen, for example, air enriched with oxygen or pure oxygen is opened inside the pyrolysis furnace 4. The gas BG flowing into the pyrolysis furnace 4 at the free end 32 of the supply pipe 30
Causes additional heat to be introduced into the pyrolysis furnace 4 by oxidation of the process gases and pyrolysis residues. Process gas S
Due to the counterflow of the G, the temperature of the inlet is not supplementary with the introduction of thermal energy, without having to introduce thermal energy.
The reaction conditions required for the initiation of the oxidation (reaction partners: the presence of the process gas SG and the pyrolysis residue R as well as the reaction temperature required for the oxidation to occur, are increased as compared to the embodiment known from US Pat. ) Is already present in the pyrolysis furnace 4 at a location that has been moved to the carry-in section 10 without the introduction of auxiliary thermal energy.

In this embodiment, the supply pipe 30 is partially filled with the process gas SG before opening to the pyrolysis furnace 4.
In a passage 20 for guiding the Thereby, the gas BG guided therein is heated in advance before flowing out into the pyrolysis furnace 4. In addition, a heat exchanger 34 is connected to the supply pipe 30.
The heat exchanger 34 receives, for example, waste heat generated in the facility or heat W from an external process.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a waste heat treatment facility according to the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

[Explanation of symbols]

 2 Screw Conveyor 4 Pyrolysis Furnace 6 Longitudinal direction of Pyrolysis Furnace 8 Heating Tube 9 Rotary Bushing 10 Carry-In Port 12 Waste Transporting Direction 14 Carry-Out Portion 16 Room 18 Sorting Device 20 Passage 22 Screw Housing 24 Exhaust Chamber System 27 Pipe system 28 Outlet outlet 29 Flow direction of partial flow of process gas 30 Air (oxygen) supply pipe 32 Free end of supply pipe 30 34 Heat exchanger A Waste F Fine component G Coarse component HG Hot gas R Thermal decomposition Residue SG Carbonization gas BG Air or oxygen

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Karl Heinz Unfelzerkut Germany 63500 Zeligenscheut Tadt Taunusshuitlase 21 (72) Inventor Hartmut Helm Germany 63303 Dreieich Grafemblüftsjlase 18 (72) ) Inventor Karl-May Germany 61118 Bad-Fuilbel Kurt-Mosdorf-Schüitlasse 6 (72) Inventor Rudolf Aarens-Boatzong, Germany 67071 Ludweiss-Hishalfen Fil-Scheidemann-Schutlase 47

Claims (15)

[Claims] 1. A pyrolysis furnace (4) extending in a longitudinal direction (6) for transporting and carbonizing waste (A), the pyrolysis furnace (4) being provided at one end with the waste (A). Loading section (10)
At the other end, a discharge portion (14) for pyrolysis residue (R) generated during dry distillation, and a process gas (SG) generated in the pyrolysis furnace (4) at the input portion (10). Exit (2
(4) A waste heat treatment facility, wherein: 2. The installation according to claim 1, further comprising a supply pipe (30) for the oxygen-containing gas (BG) which opens into the pyrolysis furnace (4). 3. The installation according to claim 2, further comprising a heat exchanger for heating the gas (BG) connected to the supply line. 4. A screw conveyor (2) with a screw housing (22) upstream of a pyrolysis furnace (4), said screw housing (22) comprising at least a part of its length a process gas (2). S
4. The installation according to claim 1, wherein the installation is heated in G). 5. The installation according to claim 4, wherein the screw housing is arranged in a passage for guiding the process gas over at least a part of its length. 6. The screw housing (22) is heated at least part of its length by a heating gas (HG) generated outside the pyrolysis furnace (4). Equipment as described. 7. A screw housing (22) for guiding a heating gas (HG) between a passage (20) for guiding a process gas (SG) and a screw housing (22).
7. The installation according to claim 6, wherein a heating jacket (25) is arranged surrounding at least part of its length. 8. The waste (A) is introduced into a pyrolysis furnace (4) which extends from a loading section (10) to a discharge section (14) in a longitudinal direction (6) at a loading section (10) and is pyrolyzed. It is conveyed in the longitudinal direction (6) of the furnace (4) and is carbonized at that time, and at least a part of the process gas (SG) generated during the carbonization is taken out from the pyrolysis furnace (4) at the discharge section (10). Waste heat treatment method. 9. An oxygen-containing gas (BG) is supplied to a pyrolysis furnace (4).
9. The method according to claim 8, wherein is provided. 10. The method according to claim 9, wherein the gas (BG) is heated before being supplied to the pyrolysis furnace (4). 11. The method according to claim 9, wherein air is used as the gas (BG). 12. The method as claimed in claim 9, wherein the gas (BG) is air enriched with oxygen or pure oxygen. 13. The process gas (S) generated in the pyrolysis furnace (4) before the waste (A) is put into the pyrolysis furnace (4).
13. Heating in G).
The method according to any one of the preceding claims. 14. A screw housing (2) of a screw conveyor (2) which is connected upstream of a pyrolysis furnace (4).
14. The method according to claim 13, wherein 2) is heated with a process gas (SG) withdrawn from the inlet for at least part of its length. 15. The screw housing (22) of the screw conveyor (2) is heated by heating gas (HG) generated by combustion outside the pyrolysis furnace (4) over at least a part of its length. The method according to claim 14, characterized in that: