JPH09273724A - Structure of exhaust heat recovery part for waste treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form the whole of a device in a compact manner and to suppress the installation area of a device by a method wherein a first flue having an air heater arranged therein and a second flue having a waste heat boiler arranged on the wake side are coupled together through a flue. SOLUTION: A first flue is composed in a square in cross section by a front wall 4a composed by tow side walls of one being a water-cooled wall and the other being a rear wall 4b and refractories 16 are mounted on the inner part of the first flue 4. Further, an air heater 5 is arranged in the first flue 4. A second flue 17 is coupled directly following the first flue 4 in such a state that combustion gas converts a direction in a zigzagging state. The second flue 17 comprises an intermediate wall 17a comprised by a water-cooled wall, a rear wall 17b, and a side wall, and a rear wall 4b by which the first flue 4 is comprised is additionally functioned as a front wall. This constitution eliminates a need for a special exhaust pipe and forms a device in a compact manner since an air heater 5 and a waste heat boiler 15 are arranged near each other, and suppresses the installation area of a device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an exhaust heat recovery unit in a waste treatment apparatus, and more specifically, it heats a waste material in a low oxygen atmosphere below atmospheric pressure to thermally decompose it, and produces a dry distillation gas and a thermal decomposition residue. Waste treatment device for producing waste materials, supplying the dry distillation gas and the combustible components separated from the pyrolysis residue to a combustor for combustion treatment, and recovering exhaust heat from the combustor. The exhaust heat recovery part structure.

[0002]

2. Description of the Related Art Waste is put into a thermal decomposition reactor as one of industrial waste treatment devices containing general waste such as municipal waste and combustibles such as waste plastic, and a low oxygen atmosphere below atmospheric pressure or non-oxidizing. It is heated in the atmosphere and pyrolyzed,
It produces dry distillation gas and a pyrolysis residue mainly consisting of non-volatile components, and after cooling the pyrolysis residue, it supplies it to a separation device and combustible components mainly composed of carbon, such as metal, pottery, and gravel. , Separated into non-combustible components made of rubble such as concrete pieces, pulverizing the combustible components, introducing the pulverized combustible components and the above-mentioned carbonization gas into a melting furnace which is a combustor, and the melting furnace The combustion ash and the combustion ash in the combustion gas generated are discharged as molten slag and cooled and solidified, while the combustion gas is supplied to the waste heat boiler via the air heater so that heat is recovered. A known waste treatment device is known (for example, JP-A-64-49816).

[0003]

In the conventional waste treatment apparatus as described above, the combustion gas discharged from the melting furnace, which is a combustor, is recovered in the air heater and then passed through the exhaust pipe. Since it was supplied to the waste heat boiler and heat was recovered again, not only was it necessary to install a special exhaust pipe, but it also required a large installation space.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the above-mentioned conventional apparatus, in which waste is kept under atmospheric pressure.
It is put into a pyrolysis reactor in a low oxygen atmosphere, and this waste is heated and pyrolyzed to produce a pyrolysis product composed of a dry distillation gas and a pyrolysis residue mainly composed of non-volatile components, and the pyrolysis residue. Combustible components separated from the product and the dry distillation gas are burned in a combustor, and the combustion gas generated in the combustor is supplied to an air heater and a waste heat boiler to recover exhaust heat. In the object processing apparatus, the air heater is arranged in a first flue which is connected to the combustor and is composed of a water cooling wall, and the first flue is connected through a second flue composed of a water cooling wall. An exhaust heat recovery unit structure in a waste treatment device is provided, which communicates with the waste heat boiler and is configured such that a rear wall forming the first flue becomes a front wall forming the second flue. It is what A refractory material is stretched in the water cooling wall that constitutes the first flue.

The hot combustion gas discharged from the combustor in the structure of the exhaust heat recovery section of such a waste treatment device is
For example, it is supplied to the first flue at 900 ° C to 950 ° C, where heat is recovered and becomes combustion gas at about 800 ° C, which is the second.
Flows into the flue of. And it is cooled by the water-cooled wall here, and it is 600 ℃ -650 ℃, and it is supplied into the waste heat boiler.
The heat is recovered again to reach 200 to 280 ° C., and the dust is supplied to the dust collector and the cleaning device arranged in the downstream.

At this time, since the rear wall forming the first flue is formed as the front wall of the second flue connected to the first flue, it is not necessary to provide a special exhaust pipe, and therefore the device is not provided. Is compact and does not require a large installation space.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an exhaust heat recovery part structure 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 device having an exhaust heat recovery unit structure according to the present invention. Reference numeral 1 denotes a thermal decomposition reactor, which is preferably composed of a horizontal rotary drum, and this thermal decomposition reactor 1 is connected in a sealed state with an inlet or the like by a sealing mechanism (not shown), and an internal air pressure is induced by an induced blower 2 The following low oxygen atmosphere is maintained.

Then, a waste a crushed by a crusher (not shown) is supplied into the thermal decomposition reactor 1 through an input port 3. Then, this waste a is separated by heating air b supplied from the air heater 5 arranged in the first flue 4 arranged in the latter stage of the thermal decomposition reactor ₁ through the line L ₁ into the waste a.
It is heated to 00 ° C. to 600 ° C., usually about 450 ° C., and thermally decomposed to produce a dry distillation gas G ₁ and a thermal decomposition residue c mainly composed of a non-volatile component.

The dry distillation gas G ₁ and the pyrolysis residue c are separated by the discharge device 6 arranged on the outlet side of the pyrolysis reactor 1, and the dry distillation gas G ₁ is a combustor via a line L _2. It is supplied to the burner 8 of the melting furnace 7. On the other hand, the thermal decomposition residue c separated by the discharging device 6 is cooled by the cooling device 9 to a temperature at which it does not ignite, for example, about 80 ° C.
Is separated into a combustible component d such as carbon and a non-combustible component e such as metal or rubble, and the non-combustible component e is contained in the container 1
Collected in 1. Then, the combustible component d is pulverized by the pulverizer 12 to, for example, 1 mm or less.

The pulverized combustible component d'is supplied to the burner 8 via the line L ₃ and the dry distillation gas G ₁ supplied from the line L ₂ and the line B ₄ by the forced blower 13. Combustion processing is performed in the melting furnace 7 in the high temperature region of about 1,300 ° C. with the combustion air f. The combustion ash generated in the melting furnace 7 is melted by this combustion process, becomes molten slag g, flows down into the water tank 14, is cooled and solidified, and the combustion gas G ₂ passes through the first flue 4 to generate waste heat. It is introduced into the boiler 15 and heat is recovered.

More specifically, as shown in FIG. 2, the first flue 4 is constituted by a front wall 4a and a rear wall 4b, which are water-cooling walls, and both side walls (not shown). A refractory material 16 is attached inside each of the first flues 4. An air heater 5 is arranged in the first flue 4. A second flue 17 is directly connected to the wake (upper end in the illustrated example) of the first flue 4 in such a manner that the combustion gas turns in a zigzag direction. The second flue 17 is composed of an intermediate wall 17a made of a water cooling wall, a rear wall 17b and a side wall (not shown), and the front wall is the rear wall 4 which constitutes the first flue 4.
b is also used. Further, waste heat boilers 15 and 15 are arranged downstream of the second flue 17.

The combustion gas G ₂ generated in the melting furnace 7 flows at 900 ° C. to 950 ° C. at the inlet (lower part) of the first flue 4,
The heat is exchanged in the air heater 5 and the temperature rises to about 800 ° C.
Combustion gas G ₂ which has flowed into the flue 17 of the flue gas and has been absorbed by the water-cooling wall around the flue gas to lower the temperature to 600 ° C to 650 ° C
And the waste heat boiler 1 directly connected to the second flue 17
5 into which additional heat is recovered.

Boiler water is used as the cooling water used for each water cooling wall of the first flue 4 and the second flue 17, and each water cooling wall and the steam drum 15a of the waste heat boiler 15 are connected by a water supply pipe 18. The heat of the combustion gas G ₂ is connected and is efficiently recovered. In this way, heat is generated by the air heater 5 installed in the first flue 4 and the waste heat boiler 15 connected through the first flue 4 and the second flue 17. The recovered combustion gas G ₂ has a relatively low temperature, is dust-removed by the dust collector 19, and is further cleaned by the cleaning device 20 to become a low-temperature clean exhaust gas G ₃ and the stack 2
1 is released into the atmosphere. On the other hand, the steam S obtained in the waste heat boiler 15 is generated by a power generation facility 23 including a steam turbine and a generator and is recovered as electric power.

[0014]

As is clear from the above description, according to the exhaust heat recovery part structure in the waste treatment apparatus of the present invention,
In the case of recovering the heat of the combustion gas discharged from the melting furnace by the air heater and the waste heat boiler, the first flue having the air heater and the second flue having the waste heat boiler on the downstream side. Since it was directly connected with the flue, no special exhaust pipe was required, and the air heater and the waste heat boiler can be arranged close to each other, so that the entire apparatus was made compact. Therefore, the installation area of the device can be suppressed.

[Brief description of drawings]

FIG. 1 is a system diagram of a waste treatment device using an exhaust heat recovery unit structure according to the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

[Explanation of symbols]

 1 Pyrolysis Reactor 2 Induction Blower 3 Input Port 4 First Flue 5 Air Heater 6 Ejector 7 Melting Furnace 8 Burner 9 Cooling Device 10 Separator 11 Container 12 Crusher 13 Forced Blower 14 Water Tank 15 Waste Heat Boiler 16 Refractory material 17 Second flue 18 Water supply pipe 19 Dust collector 20 Cleaning device 21 Chimney 23 Power generation facility

Claims (2)

[Claims] 1. A heat treatment method in which a waste is put into a pyrolysis reactor whose internal pressure is lower than atmospheric pressure, the waste is heated to be pyrolyzed, and which is composed of a dry distillation gas and a pyrolysis residue mainly composed of non-volatile components. A decomposition product is generated, the combustible component separated from the thermal decomposition residue and the dry distillation gas are burnt in a combustor, and the combustion gas generated in the combustor is supplied to an air heater and a waste heat boiler. In the waste treatment device configured to recover the exhaust heat, the air heater is arranged in a first flue that is connected to the combustor and includes a water cooling wall, and the first flue is connected to the first flue. The waste heat boiler is connected to the waste heat boiler via a second flue that is a water-cooling wall, and the rear wall that constitutes the first flue is a front wall that constitutes the second flue. An exhaust heat recovery unit structure in a waste treatment device. 2. The first flue according to claim 1, wherein a refractory material is stretched in the water cooling wall.