JPH109534A - Waste treatment equipment - Google Patents

Abstract

(57) Abstract: Heated air heated to a control temperature is heated by a second air heater so as to prevent high-temperature corrosion of first air heating means (high-temperature air heater) for applying combustion gas. By means of reheating, heated air at a predetermined pyrolysis temperature is obtained. SOLUTION: Heated air heated by combustion gas is supplied from a first air heating means 40, and waste air a is heated by the heated air.
And a waste pyrolysis drum configured to thermally decompose waste a to generate a dry distillation gas and a pyrolysis residue. The heated air is heated at high temperature by the first air heating means 40. A second air heating means (air heater) 41 is provided which is heated to a control temperature at which the temperature can be prevented and the control temperature is reheated to raise the temperature to the pyrolysis temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to industrial waste such as waste (general waste such as municipal waste from homes and offices, waste plastic, car shredder dust, waste office equipment, electronic equipment, cosmetics, etc.). Waste treatment equipment, which heats heated air heated to a control temperature that can prevent high-temperature corrosion and raises the temperature to the pyrolysis temperature. And a waste pyrolysis method.

[0002]

2. Description of the Related Art Conventionally, as one of apparatuses for treating industrial waste 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. To produce a carbonized gas and a pyrolysis residue mainly composed of non-volatile components. After further cooling the pyrolysis residue, the pyrolysis residue is led to a separator, where the combustible component and, for example, metal And non-combustible components such as porcelain, gravel, concrete fragments, etc., and crush the flammable components, guide the crushed combustible components and the carbonization gas to a melting furnace, and burn them in this melting furnace. There is known a waste treatment apparatus in which the combustion ash generated is converted into molten slag, and this molten slag is discharged and solidified by cooling (for example, see JP-A-1-49816).

[0003] In the waste pyrolysis drum, a rotary drum equipped with a heat transfer tube, which is a heat transfer surface for indirect heating, is usually used, but the waste supplied to the waste pyrolysis drum is low. It is thermally decomposed in an oxygen atmosphere at 300 ° C. to 600 ° C., usually about 450 ° C. Then, the heated air supplied to the rotary drum exchanges heat with combustion gas generated in the melting furnace by first air heating means (high-temperature air heater).
It is supplied to the rotating drum as high-temperature heating air at 0 ° C. to 600 ° C., and the waste put in the rotating drum is indirectly heated to be thermally decomposed.

[0004]

In a conventional waste disposal apparatus, a high-temperature air heater (first air heating means) is used.
Because the heating air is heated by using the combustion gas generated in the melting furnace, when high-temperature heating air of 450 to 600 ° C. is used, high-temperature corrosion occurs in a heat transfer tube of a high-temperature air heater or the like, As a result, there is a problem that the durability of the high-temperature air heater is reduced. For this reason, it is conceivable to form the high-temperature air heater, particularly the heat transfer tube, with a high-temperature corrosion-resistant material. However, in this case, there is a problem that the manufacturing cost is increased.

An object of the present invention is to reheat the heated air heated to the control temperature by the second air heating means so as to prevent high-temperature corrosion by the first air heating means for applying the combustion gas, By obtaining heated air at a predetermined temperature,
It is an object of the present invention to provide a waste treatment apparatus and a waste pyrolysis method capable of simplifying the apparatus and reducing the cost.

[0006]

In order to achieve the above object, a waste treatment apparatus according to the present invention is characterized in that heated air heated by a combustion gas is supplied from a first air heating means, and the waste air is discarded by the heated air. In a waste treatment apparatus that heats materials indirectly and pyrolyzes wastes to produce carbonized gas and pyrolysis residues, the heated air can prevent high-temperature corrosion of the first air heating means A second air heating means is provided, which is heated to an appropriate control temperature and reheats the control temperature to a pyrolysis temperature.

The control temperature is about 400 ° C.
The thermal decomposition temperature may be 400 ° C. or higher.

[0008] The second air heating means may use an electric heater.

Further, in the waste pyrolysis method, the first
Supplying heated air heated by the combustion gas from the air heating means, heating the waste indirectly by the heated air, and pyrolyzing the waste to generate a carbonized gas and a pyrolysis residue In the waste pyrolysis method comprising the steps of: separating a pyrolysis residue into a combustible component and a non-combustible component and discharging the same, the heated air can prevent high-temperature corrosion of the first air heating means The method includes a step of heating to the control temperature, and a step of reheating the control temperature by the second air heating means to raise the temperature to the thermal decomposition temperature.

The control temperature is about 400 ° C.
The thermal decomposition temperature may be 400 ° C. or higher.

According to this embodiment, heated air heated to a control temperature of about 400 ° C. is reheated by the second air heating means so as to prevent high-temperature corrosion of the first air heating means, and By heating to a temperature of 400 ° C. or higher, the durability of the first air heating means is improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, the waste disposal apparatus using the waste thermal decomposition drum 6 according to the present embodiment thermally decomposes the supplied waste a by indirect heating with heated air.
Pyrolysis gas G1 and pyrolysis residue b of mainly non-volatile components b
Waste heat cracking drum 6 including a heat exchange section 6a for generating a gas, a discharge device 10 for separating and discharging the carbonization gas G1 and the pyrolysis residue b, and the pyrolysis discharged from the discharge device 10. The residue b is converted into a combustible component d and non-combustible components e1 and e2.
A melting device 9 that burns the carbonization gas G1 and the combustible component d and discharges combustion ash as molten slag, and a first air that is built in the melting furnace 9 and supplies heated air. And a heating means (high-temperature air heater) 40, and the waste pyrolysis drum 6 supplies heated air heated to a control temperature of about 400 ° C. at which high-temperature corrosion of the first air heating means 40 can be prevented. Reheat and control temperature 400
A second air heating means (air heater) 41 for increasing the temperature from about 0 ° C. to a thermal decomposition temperature of 400 ° C. or more is provided.

The heating source of the second air heating means 41 is preferably formed of an electric heater, and the electric heater is formed of, for example, an electric heater or a current heating tube provided in a pipe. The second air heating means 41 may be a kerosene-fired burner.

That is, as shown in FIG. 2, the waste pyrolysis drum has a hollow cylindrical drum body (rotary drum) 7 mounted on a plurality of rollers 31 driven by a drive source (not shown) and rotates at about 2 rpm. A heated air outlet header 33 in which the screw feeder 5 is inserted into the inner pipe 33b is slidably connected to one end face via a seal, and the input port 4 for the waste a can be connected to the screw feeder 5. I have. A heating air inlet header 34 is slidably connected to the other end surface of the drum body 7 via a seal, and a tube sheet 33 of the heating air outlet side header 33 is provided inside the drum body 7.
a and a plurality of heat transfer tubes 8 having both ends fixed to the tube plate 34 a of the heated air inlet side header 34 are disposed on the inner periphery of the drum body 7. The heat transfer tube 8 is made of a heat and corrosion resistant material such as austenitic stainless steel (SUS316, SUS31).
0SS, SUS321 or SUS347), 50Cr-
50Ni, Incoloy, Inconel, or the like. The other end of the heated air inlet side header 34 is directly connected to the heated air inlet channel 35 and the discharge device 10, the outlet 10 a of the carbonization gas G <b> 1 at the upper portion of the discharge device 10, and the pyrolysis residue b (combustible And a discharge port 10b for the component d and the non-combustible components e1 and e2).

The tube sheet 3 of the header 34 on the heated air inlet side
A discharge pipe 36 is connected to the discharge device 10 through a discharge hole 34b formed in the heating air inlet channel 35 through the discharge hole 34b formed in the discharge device 4a. To be discharged. The air heater 41 may be a kerosene burner, for example, may have a structure of an air heating furnace, and may have a structure having a kerosene burner as a heating source or a structure in which the kerosene burner of the air heater 41 is replaced with an electric heater. It is assumed that a control switch or the like for adjusting the current according to the air temperature is provided.

The operation of the waste disposal apparatus will now be described with reference to FIGS. The waste a such as municipal waste is supplied to the crusher 1 of, for example, a twin-screw shear type disposed in the receiving yard A by the first conveyor 2, and is, for example, 150 m.
m or less. The pulverized waste a is supplied to the heat exchange unit 6 a by the second conveyor 3 from the input port 4 via the screw feeder 5. This heat exchange section 6a
A plurality of heat transfer tubes 8 extend along the inner peripheral wall of the rotating drum body 7.
Are arranged, and the internal pressure thereof is maintained at an atmospheric pressure of about −10 mmAq or lower by an unillustrated sealing mechanism. The first air heating means 40 is a hot air heater incorporated in the downstream of the melting furnace 9 is acted combustion gas G ₂ of the melting furnace 9, wherein heated air is capable of preventing the high temperature corrosion After being heated below the control temperature of 400 ° C,
Heated air H reheated to at least 400 ° C., for example, about 450 ° C. to 550 ° C. by the second air heating means 41 as an air heater is supplied into the heat transfer tube 8 from the line L1. Waste a is 300 ℃ ～ 6
Indirect heating to 00 ° C., usually to about 450 ° C. Therefore, the waste a supplied into the heat exchange section 6a is thermally decomposed, and the carbonization gas G1 and mainly the non-volatile pyrolysis residue b are generated. The heated air H supplied to the heat exchanging section 6a becomes relatively low-temperature heated air Ha of about 250 ° C., and is again guided to the first air heating means 40 from the line L ₁ a.

The carbonized gas G1 generated in the heat exchange section 6a
The pyrolysis residue b is separated from the pyrolysis residue b by the discharge device 10, the dry distillation gas G 1 is supplied to the burner 11 of the melting furnace 9 via the line L 3, and the pyrolysis residue b is cooled to 80 ° C. by the cooling device 12 to prevent ignition. After cooling to the extent, for example, a sieve, magnetic separation,
It is supplied to a known separation device 13 such as an eddy current type, a centrifugal type or a wind separation type, where the combustible component d containing fine ash is contained.
And a metal component e1 and a non-metal component e which are non-combustible components.
And 2.

The combustible component d is finely pulverized to, for example, 1 mm or less by a pulverizer 14, supplied to a burner 11 of a melting furnace 9 via a line L4, and a dry distillation gas G1 supplied from a line L3 and a blower 15 to a line. The combustion air F supplied from L5 is burned in a high temperature range of about 1300 ° C., and the combustion ash generated at this time becomes molten slag, adheres and flows down to the inner wall of the melting furnace 9, and is discharged from the discharge port 16 to the water tank 17.
It flows down and cools and solidifies. The solidified slag is used as a building material such as a pavement material.

On the other hand, the metal component e1, which is a non-combustible component, enters the container 18 and is collected and reused, and the non-metallic component e2 is subjected to landfill or is pulverized by the pulverizer 19 and passed through the line L6. It is supplied into the melting furnace 9 and collected and reused as slag.

The high-temperature exhaust gas G2 generated in the melting furnace 9 is
Waste heat boiler 2 from line L7 via air heating means 40
1, the heat is collected, the dust is removed by the dust collectors 22a, 22b, and the low-temperature clean exhaust gas G3 is discharged to the chimney 23 to the atmosphere. A part of this clean exhaust gas G3
8, and is supplied to the cooling device 12. The steam generated in the waste heat boiler 21 rotates a steam turbine connected to the power generator 24. In the first air heating means 40, the high-temperature exhaust gas G2
Is heated by the second air heating means 41 such as an air heating furnace to a temperature equal to or higher than the thermal decomposition temperature and supplied to the heat exchange section 6a. Second air heating means 41
Is formed of an electric heater, the power generated by the power generator 24 having the steam turbine or the purchased power is supplied.

Next, as another embodiment of the present invention, as shown in FIG.
A step in which heated air heated by the combustion gas is supplied,
A step of indirectly heating and thermally decomposing the waste a with heated air through the heat transfer tube 8, a step of generating the carbonization gas G1 and a pyrolysis residue b mainly composed of a non-volatile component, A waste air pyrolysis method comprising a step of separating a combustible component d and non-combustible components e1 and e2, wherein the heated air is controlled at a control temperature of 400 ° C. at which high temperature corrosion of the first air heating means 40 can be prevented. And a step of reheating the control temperature of about 400 ° C. by the second air heating means 41 to raise the temperature to a thermal decomposition temperature of 400 ° C. or more.

According to this embodiment, first, when the waste is supplied to the heat exchange section, the waste is indirectly heated in a low-oxygen atmosphere by the heated air and thermally decomposed, and is composed of the carbonized gas and mainly the non-volatile components. And pyrolysis residues. In this pyrolysis process, the waste is 300 ° C to 600 ° C from normal temperature, usually 4 ° C.
The temperature is indirectly heated to about 50 ° C. by heated air. The heated air is heated to a control temperature of about 400 ° C. by the first air heating means 40 and then heated by the second air heating means 4.
1 and the thermal decomposition temperature 400 in the heat exchange section 6a.
~ 450 ° C is maintained. The heating source of the second air heating means may be either a kerosene burner or an electric heater, but the electric heater is easy to control the temperature and does not generate exhaust gas and the like, so that it has high thermal efficiency and can keep a clean state. . Reheating with the second air heating means using kerosene as the heating source
Fuel such as kerosene is always purchased and stored, which complicates management and may increase fuel cost. Therefore, a second air heating means using an electric heater instead of fuel such as kerosene is provided. It is desired. By maintaining an environment at a control temperature of about 400 ° C., high-temperature corrosion of a heat transfer tube or the like of a high-temperature air heater is reduced.

Then, the carbonized gas and the pyrolysis residue generated in the heat exchange section are separated by a discharge device, and the carbonized gas is supplied to a melting furnace as a combustor, while the pyrolysis residue is cooled. And flammable components and fine-grained ash in the separator,
It is separated into coarse-grained non-combustible components made of metal such as iron or aluminum, and the flammable components and fine-grained ash therein are supplied to a melting furnace and burned. In this case, about 1
Since the combustion ash and ash are kept at a high temperature of about 300 ° C., the combustion ash and ash are melted to form molten slag and adhere to the inner wall of the melting furnace and flow down. The non-combustible components are separated into metal components such as iron and non-metal components such as pottery, the metal components are reused, and the non-metal components are mixed in landfill or, if necessary, mixed with molten slag and paved. Reused as materials.

[0024]

According to the present invention, after the heated air is heated to the control temperature by the first air heating means, it is refired by the second air heating means to secure the pyrolysis temperature. The hot corrosion environment is improved and the life of the equipment is extended. When an electric heating element is used as the heat source of the second air heating means, there is no need to manage the fuel, which has the effect of improving economic efficiency.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a waste treatment apparatus provided with a waste pyrolysis drum according to one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing the waste pyrolysis drum of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crusher 2 1st conveyor 3 2nd conveyor 4 Input port 5 Screw feeder 6 Waste pyrolysis drum 6a Heat exchange part 7 Drum main body 8 Heat transfer tube 9 Melting furnace 10 Discharge device 11 Burner 12 Cooling device 13 Separation device 14 Crusher 15 Blower 16 Discharge port 17 Water tank 18 Container 19 Crusher 21 Waste heat boiler 22a, 22b Dust collector 23 Chimney 24 Generator 40 High temperature air heater 41 Air heater

Claims (5)

[Claims] 1. A heated air heated by a combustion gas is supplied from a first air heating means to indirectly heat a waste by the heated air, and to thermally decompose the waste to pyrolyze a pyrolysis gas and a pyrolysis residue. In the waste treatment apparatus, the heated air is heated to a control temperature capable of preventing high-temperature corrosion of the first air heating means, and the control temperature is reheated to pyrolyze the wastewater. A waste treatment apparatus comprising a second air heating means for increasing a temperature to a temperature. 2. The waste treatment apparatus according to claim 1, wherein the control temperature is about 400 ° C., and the thermal decomposition temperature is 400 ° C. or more. 3. The waste treatment apparatus according to claim 1, wherein an electric heating element is used as the second air heating means. 4. A step of supplying heated air heated by a combustion gas from a first air heating means, a step of indirectly heating waste with the heated air, and a step of pyrolyzing the waste to form a carbonized gas. And a step of generating a pyrolysis residue, and a step of separating and discharging the pyrolysis residue into a combustible component and a non-combustible component. A step of heating the air heating means to a control temperature capable of preventing high-temperature corrosion of the air heating means, and a step of reheating the control temperature by a second air heating means to raise the temperature to a thermal decomposition temperature. And waste pyrolysis method. 5. The waste pyrolysis method according to claim 4, wherein the control temperature is about 400 ° C., and the thermal decomposition temperature is 400 ° C. or more.