JP2991639B2 - Waste incineration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to organic waste sludge from building waste, food processing waste, sludge and sludge from paper or pulp manufacturing waste, pharmaceutical manufacturing waste, industrial waste, and so-called waste generated from ordinary households. It relates to a waste incinerator suitable for incineration of waste such as municipal solid waste, and in particular,
The present invention relates to a waste incinerator including a fluidized incinerator that minimizes the generation of harmful substances such as nitrogen oxides, dioxins, and carbon monoxide.

[0002]

2. Description of the Related Art Conventionally, waste incinerators are mainly constituted by a waste incinerator, a heat exchanger for recovering waste heat, or a dust collector such as a boiler and a bag filter.
Of these, waste incinerators are the most important part for drying and incinerating waste. An example of this waste incinerator is shown in FIG. 2 with reference to JP-A-5-10519.
This waste incinerator is capable of co-firing foreign matter. The incinerator 01 is provided with a fluidized bed section consisting of an upper fluidized bed section 02 and a lower fluidized bed section 03. And
In the upper fluidized bed section 02, refuse containing no foreign matter is burned, and in the lower fluidized bed section 03, refuse containing foreign matter is burned. With such a configuration, the combustible component gasified by the combustion in the lower fluidized bed portion 03 is supplied as a fluidizing gas to the upper fluidized bed portion 02 and also serves as a combustion heat source in the upper fluidized bed portion 02. Further, the heat load fluctuation of the lower fluidized bed portion 03 is reduced because it is absorbed and stored in the fluidized medium of the upper fluidized bed portion 02, and the fluctuation of the incineration temperature is suppressed even if the property of the foreign matter changes.

[0003] Further, the combustion residue and the fluid medium in the lower fluidized bed section 03 are extracted and separated by a foreign matter separator 04, and the separated fluid medium is moved to the upper fluidized bed section 02. On the other hand, the excess fluid medium in the upper fluidized bed section 02 is moved to the lower fluidized bed section 03 by the fluidized medium falling device 05. In this way, the fluidized beds of the fluidized bed sections 02 and 03 at each stage hold an appropriate fluidized medium and improve the combustion efficiency.

In the above waste incinerator, it is necessary to separate waste containing no foreign matter from waste containing foreign matter. However, the separation is actually a very difficult operation, and it is necessary to separate the waste containing foreign matter. No waste is separated and the above-mentioned upper fluidized bed section 0
It is difficult to uniformly burn large and small irregular shaped refuse even if it is incinerated in 2, and the combustion form is gasification combustion under excess air in the medium layer, so that nitrogen oxides, dioxin, Alternatively, there is a problem in preventing generation of harmful gases such as carbon monoxide.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and has been made in a waste incineration apparatus in which waste containing no foreign matter and waste containing foreign matter are collected without discrimination. The main task is to minimize the generation of harmful gases such as nitrogen oxides, dioxins, or carbon monoxide while being able to incinerate and reduce the amount of exhaust gas. Provided is a waste incinerator characterized by an incinerator capable of recovering valuable resources, controlling the incineration temperature while recovering heat, and the like.

[0006]

SUMMARY OF THE INVENTION The above problem is caused by waste disposal.
Pyrolysis zone with inlet and compartment adjacent below it
The combustion zone and the upper space of the pyrolysis zone are linked.
A waste incineration system comprising by laminating a clean combustion zone passing, (1) while fluidized by combustion gas supplied from the combustion zone downward by thermal decomposition of waste in a reducing atmosphere inflammable A pyrolysis zone having a fluidized bed for separating gas; (2) means for extracting unburned solids from the pyrolysis zone to separate unburned combustibles and incombustibles; (3)
(4) a combustion zone having a fluidized bed for burning the separated unburned combustibles, (4) means for extracting a fluidized medium from the fluidized bed of the combustion zone and supplying the fluidized medium to the fluidized bed of the upper pyrolysis zone; 5) the combustion is continuously provided on the upper portion of the pyrolysis zone, and other combustible gases in the combustion gas supplied from the combustion zone and separated combustible gas by thermal cracking zone in the presence of sufficient air The problem can be solved by a waste incineration apparatus including an incinerator characterized by having a clean combustion zone for causing the waste to incinerate.

Further, according to the present invention, the support member of the fluidized bed portion of the pyrolysis zone is an inclined dispersion plate and also serves as a ceiling member forming a combustion zone. Embodied by Further, the present invention is suitably embodied by a waste incinerator according to claim 1 or 2, wherein a heat exchange pipe for circulating a heat recovery fluid is provided in a flow path of the fluid medium in the combustion zone.

[0008]

As described above, in the incinerator according to the present invention, the incineration operation of the waste to be incinerated is performed by (1) a fluidized bed for separating the combustible gas by thermally decomposing the inputted waste at a relatively low temperature. (2) a combustion zone defined below and adjacent to the pyrolysis zone, having a fluidized bed for burning the unburned combustibles obtained from the pyrolysis zone at a relatively high temperature. And (3) a clean combustion zone in which the combustible gas separated in the pyrolysis zone and other combustible gases in the combustion gas supplied from the combustion zone to the pyrolysis zone are gas-burned in the presence of sufficient air. It is done in parcels.
Therefore, first, waste is thermally decomposed in a pyrolysis zone under a reducing atmosphere, and the separated combustible gas is finally burned in the free combustion zone in the presence of sufficient air, so it is slow at high temperatures. And uniform combustion becomes possible,
Generation of harmful gases such as nitrogen oxides, dioxins, and carbon monoxide can be prevented as much as possible.

On the other hand, the unburned solids remaining in the pyrolysis zone are mainly composed of inorganic incombustibles including metal, unburned combustibles such as unburned carbon, and a fluid medium forming a fluidized bed. Metallic substances such as iron and aluminum are hardly oxidized because they are thermally decomposed below, and these metallic substances can be recovered as valuables by means of separating unburned combustibles and incombustibles. Further, when the waste is thermally decomposed at a temperature of 250 to 650 ° C. in the pyrolysis zone, the corrosive component-containing substance such as chlorine contained therein is decomposed and the corrosive component is separated, so that it is supplied to the combustion zone. Unburned combustibles have the distinct advantage of not containing these corrosive components.

The separated unburned combustibles are burned alone in the combustion zone. However, since the unburned combustibles are finely crushed in the fluidized bed of the thermal decomposition zone, Combustion of unburned combustibles is performed very uniformly, which has a remarkable advantage in preventing generation of harmful gas. Further, since the combustion gas is ultimately completely burned in the clean combustion zone in the presence of sufficient air, the generation of harmful gases such as nitrogen oxides and dioxins is extremely small.

As described above, according to the present invention, while it is possible to incinerate waste containing no foreign matter and waste containing foreign matter without distinguishing them, it is possible to reduce harmful gases such as nitrogen oxides, dioxins and carbon monoxide. In addition to minimizing the generation of waste, the incineration of waste is divided into a pyrolysis zone and a combustion zone, enabling uniform combustion. It is possible to reduce the amount of exhaust gas finally.

According to the second aspect of the present invention, since the supporting member of the fluidized bed portion of the pyrolysis zone is an inclined dispersion plate and also serves as a ceiling member forming a combustion zone, incineration is performed. The furnace can be made compact, no separate air supply is required to drive the fluidized bed of the pyrolysis zone, or usually the pyrolysis temperature of the waste in the pyrolysis zone is Since it is lower than the combustion temperature of the unburned combustibles in the above, there is an advantage that a separate heating device for the pyrolysis zone is not required.

According to the third aspect of the present invention, since the heat exchange pipe for circulating the heat recovery fluid is provided in the flow path of the flow medium in the combustion zone, heat recovery is efficiently performed. There is an advantage that the temperature can be controlled by lowering the temperature of the fluidized medium to suppress overheating of the pyrolysis zone. In addition, since the flow path of the fluid medium is filled with the fluid medium moving from the above-described combustion zone where corrosive components such as chlorine are not present, there is no possibility that the heat exchange pipe is corroded. .

[0015]

Next, the present invention will be described in detail based on an embodiment shown in FIG. In FIG. 1, an incinerator 1 according to the present invention is constructed of a casing 11 made of metal or the like lined with refractory bricks or irregular refractories, and includes a pyrolysis zone 2, a combustion zone 3, and a clean zone. A combustion zone 4 is vertically stacked, and an incombustibles separation device 5 and a fluid medium moving device 6 are additionally provided.

First, the middle pyrolysis zone 2 is
In order to thermally decompose the waste to be incinerated from 5, it is a zone partitioned above and adjacent to the lower combustion zone 3, and the inclined dispersion plate 22 forms the bottom surface. The fluidized medium is filled on the inclined dispersion plate 22 and circulates in the opposite direction to the clock hand by the combustion gas supplied from the combustion zone 3 (in FIG. 1). Is formed. Also,
An unburned solids outlet 24 is provided near the lowermost portion of the bottom surface and communicates with the incombustible material separation device 5, and a fluid medium supply port 23 is provided near the uppermost portion of the bottom surface to move the fluid medium. The device 6 is in communication. In this embodiment, the upper space of the thermal decomposition zone 2 communicates with the upper clean combustion zone 4.

The operation of the pyrolysis zone 2 formed as described above will be described. First, in the fluidized bed section 21, the fluidized medium has an average flow velocity of 0.3 to 2 m / s, preferably 0.
It is controlled to have a slow flow rate at a relatively low temperature of 3 to 0.6 m / s and a temperature of 350 to 650 ° C, preferably 550 to 600 ° C. The waste supplied from the inlet 25 is mixed, dried, crushed, and thermally decomposed in the fluidized bed 21 to separate combustible gas. In this case, in order to efficiently separate combustible gas, waste It is important to thermally decompose under a reducing atmosphere. In this embodiment, since the fluidized bed portion 21 that performs the bubbling motion by the combustion gas supplied from the lower combustion zone 3 is formed, it is ensured that the thermal decomposition is performed in a reducing atmosphere. It becomes.

Further, the combustible gas generated is sent from the upper space to the adjacent clean combustion zone 4, and the unburned solid separated from the combustible gas is taken out of the outlet 24 with the fluid medium and discharged to the outside. Is sent to the incombustible substance separation device 5 attached to the above. In this case, the substance containing a corrosive component such as a chlorine component in the waste is decomposed when subjected to the above treatment, and the corrosive component is gasified and separated. It does not contain such corrosive components.

Next, the incombustible substance separation apparatus 5 separates a group of inorganic incombustibles mainly including metallic substances from unburned solids such as unburned carbon (referred to as char) by particle size sorting and magnetic force sorting. Separate into combustible and fluid media groups. In this case, since metals and the like are heated to a low temperature in a reducing atmosphere, irons are not oxidized, and aluminums are discharged as they are without melting and can be easily separated and recovered. Further, since unburned combustibles such as unburned carbon have undergone thermal decomposition and crushing in the fluidized bed 21, they have lost their original shape and have changed into granular forms, so that they can be easily separated. The group of the unburned combustible material such as unburned carbon and the fluid medium thus separated is transferred from the incombustible material separation device 5 to the combustion zone 3.

Next, a lower combustion zone 3 for burning unburned combustibles mainly composed of unburned carbon is a zone adjacent to the lower part of the thermal decomposition zone 2 and partitioned by the inclined dispersion plate 22 as a ceiling member. And a fluidized bed section 31
Are formed. The fluidized bed section 31 receives supply of granular unburned combustibles such as unburned carbon and a fluid medium from the incombustibles separation device 5, and burns the unburned combustibles with primary air ejected from the dispersion pipe 32. A bubbling fluidized bed is formed. Fluidized bed 3 of this combustion zone 3
In 1, the flowing medium has an average flow velocity of 0.3 to 2.0 m /
s, preferably 1.0 to 1.5 m / s, temperature 700 to
The fluidized bed becomes a rapid fluidized bed at a relatively high temperature of 900 ° C., preferably 800 to 850 ° C., so that the particulate unburned combustible can be uniformly burned at a high temperature.

A fluid medium outlet 34 is provided below the fluidized bed portion 31 of the combustion zone 3, and the fluid medium taken out from the fluid medium outlet 34 is supplied to the thermal decomposition zone 2 by the fluid medium transfer device 6. It is conveyed and supplied from the supply port 25 of the fluidized medium to the fluidized bed 21 of the pyrolysis zone 2. In this way, since the amount of heat is supplied to the fluidized bed section 21 of the thermal decomposition zone 2 by the moving medium, the temperature of the fluidized bed section 21 of the thermal decomposition zone 2 is controlled by controlling the weight and temperature of the moving medium. You can do it. Further, in the case where the heat exchange pipe 33 for circulating the heat recovery fluid is provided in the flow path near the outlet 34 for the fluid medium, the heat recovery becomes possible and the temperature of the fluidized bed 21 is adjusted. It is also possible to control the operation of thermal decomposition. In this case, as described above, since the corrosive gas such as the chlorine gas is not generated from the combustion in the combustion zone 3, stable heat exchange can be performed for a long time.

Further, the upper clean combustion zone 4 includes:
This is a zone continuously partitioned into the upper space of the thermal decomposition zone 2, and is a space in which an exhaust gas outlet 41 is provided above. In this clean combustion zone 4, the middle stage
The flammable gas generated in the pyrolysis zone 2 and the other flammable gas in the combustion gas generated in the lower combustion zone 3 flowing through the pyrolysis zone 2 are finally heated to a temperature in the presence of sufficient air. Gas combustion is performed under high temperature conditions of 800 to 900 ° C. For this purpose, a secondary air supply port 42 or a tertiary air or cooling water blowing device (neither is shown) is provided at an appropriate position. In this way,
In the clean combustion zone 4, high-temperature and uniform gas combustion is possible, and exhaust gas from the incinerator 1 can be discharged as containing no harmful gas such as nitrogen oxide, dioxin, or carbon monoxide. You can.

In this embodiment, the incineration of the waste is divided into a pyrolysis zone 2 for decomposing the waste, a combustion zone 3 for burning the unburned carbon, and a free combustion zone 4 for performing the gas combustion to achieve uniform combustion. As a result, the amount of combustion air can be reduced from the conventional air ratio of 2.0 to 2.5 to about 1.5, so that the amount of exhaust gas can be greatly reduced in the end.

[0024]

Since the incinerator of the waste incinerator according to the present invention is constructed as described above, it is possible to collectively incinerate garbage containing no foreign matter and garbage containing foreign matter without distinguishing them. Possible, and nitrogen oxides, dioxins,
Alternatively, it has a remarkable effect of minimizing the generation of harmful gases such as carbon monoxide and reducing the total amount of exhaust gas. Furthermore, recover metals in waste as valuable resources.
There are excellent effects such as easy thermal decomposition control while exchanging heat in the moving passage of the non-corrosive fluid medium in the combustion zone, or reduction of the total amount of exhaust gas. Therefore, the present invention has an extremely large industrial value as a waste incinerator which has solved the conventional problems.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional two-stage fluidized bed incinerator.

[Explanation of symbols]

1 incinerator, 2 pyrolysis zone, 21 fluidized bed, 22
Inclined dispersion plate, 3 combustion zone, 31 fluidized bed, 33
Heat exchange pipe, 4 clean combustion zone, 5 incombustible substance separation device, 6 fluid medium transfer device.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F23C 11/02 ZAB F23C 11/02 ZAB F23G 5/30 ZAB F23G 5/30 ZABE ZABK 5/46 ZAB 5/46 ZABZ 5/50 ZAB 5/50 ZABE F23L 9/04 F23L 9/04 (56) References JP-A-7-301411 (JP, A) JP-A-51-63576 (JP, A) JP-A-64-79504 (JP, A) (58) Fields investigated (Int.Cl. ⁶ , DB name) F23G 7/00 102 F23G 7/00 ZAB F23C 11/00 323 F23C 11/00 ZAB F23C 11/02 312 F23C 11/02 ZAB F23G 5 / 30 ZAB F23G 5/46 ZAB F23G 5/50 ZAB F23L 9/04

Claims (3)

(57) [Claims] 1. A pyrolysis zone having a waste input port ,
A combustion zone that is defined adjacent to the lower side of the pyrolysis
Product and clean-burning zone zone headspace communicates
A waste incinerator equipped in layers , comprising: (1) flowing by combustion gas supplied from a lower combustion zone;
A pyrolysis zone having a fluidized bed for separating the combustible gas by thermally decomposing the waste under a reducing atmosphere; (2) extracting unburned solids from the pyrolysis zone to separate unburned combustibles and incombustibles (3) a combustion zone having a fluidized bed for burning the separated unburned combustibles; and (4) a fluidized medium is withdrawn from the fluidized bed of the combustion zone to a fluidized bed of an upper pyrolysis zone. means for supplying, and (5) is provided continuously on the top of the pyrolysis zone, and other combustible gases in the combustion gas supplied from the combustion zone and separated combustible gas by thermal cracking zone sufficient A waste incineration apparatus including an incinerator, comprising: a clean combustion zone for burning in the presence of air. 2. The waste incinerator according to claim 1, wherein the support member of the fluidized bed portion of the pyrolysis zone is an inclined dispersion plate and also serves as a ceiling member forming a combustion zone. 3. The waste incinerator according to claim 1, wherein a heat exchange pipe for circulating a heat recovery fluid is provided in a flow path of the fluid medium in the combustion zone.