JP2991638B2 - 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-bed furnace 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 of drying, cracking and incineration of waste. An example of this waste incinerator is shown in FIG. 3 with reference to JP-A-5-10519. The waste incinerator is capable of mixing and mixing foreign substances. An incinerator 01 is provided with a fluidized bed section composed of an upper fluidized bed section 02 and a lower fluidized bed section 03. The upper fluidized bed section 02 burns refuse containing no foreign matter, and the lower fluidized bed section 03 burns refuse containing foreign matter. 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, it is said that fluctuations in the heat load of the lower fluidized bed portion 03 are mitigated because they are absorbed and stored in the fluidized sand of the upper fluidized bed portion 02, and fluctuations in the incineration temperature are suppressed even when the properties of the foreign matter change.

[0003] Further, the combustion residue and fluidized sand in the lower fluidized bed section 03 are extracted and separated by a foreign matter separator 04,
The separated fluidized sand is moved to the upper fluidized bed section 01. On the other hand, excess fluidized sand in the upper fluidized bed portion 02 is moved to the lower fluidized bed portion 03 by the fluidized sand falling device 05. In this way, the fluidized bed portion 0 of each stage
It is said that the appropriate fluidized sand is held in the fluidized beds 2 and 03, and the combustion efficiency is improved.

[0004] In the above waste incinerator, it is actually very difficult to separate waste containing no foreign matter from waste containing foreign matter. Even if incinerated in the fluidized bed section 02, it is difficult to uniformly burn the large and small irregular shaped refuse, and since the combustion form is gasification combustion under excess air in the sand layer, nitrogen oxides, Dioxin,
Alternatively, there is a problem in preventing generation of harmful gases such as carbon monoxide. In addition, since the incinerator has two upper and lower stages, there is a disadvantage that the furnace height is increased.

[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. Waste characterized by an incinerator that can be recovered as valuable resources, reduce the flow power of fluidized sand, control the incineration temperature while recovering heat, and facilitate upsizing according to the required processing capacity Provide an incinerator.

[0006]

SUMMARY OF THE INVENTION The problems described above are as follows. (1) Separation of combustible gas by heating and decomposing waste in a reducing atmosphere.
A pyrolysis zone having a fluidized bed , (2) means for extracting unburned solids from the pyrolysis zone to separate unburned combustibles and incombustibles, and (3) burning the separated unburned combustibles. flow
Combustion zone having a floor portion, and (4) and a clean combustion zone for burning residual combustibles in the combustion gas generated from the combustible gas and the combustion zone separated by the thermal cracking zone in the presence of sufficient air The fluidized bed of the combustion zone
Section and the fluidized bed section of the pyrolysis zone are adjacent via a partition wall
And the level of fluidized sand in the combustion zone
Bell located above the level of fluidized sand in the pyrolysis zone
And the fluid sand in the combustion zone overflows the bulkhead.
To move in the fluidized bed direction of the pyrolysis zone.
And the overflowed fluid sand
Movement formed along and below the solution zone inner wall
Before installing a heat exchange pipe through which heat recovery fluid flows through the layer
The problem can be solved by a waste incinerator including an incinerator characterized in that the temperature of the fluidized bed in the pyrolysis zone can be adjusted .

[0007]

Further, prior SL by a partition wall provided on at least one side of the fluidized bed of the combustion zone, the fluidized sand is moved downward overflows the partition wall from the fluidized bed unit is refluxed to the original fluidized bed section to form a moving bed unit, disposed heat exchange pipe for circulating the heat recovery fluid into the moving layer portion, wherein
It can be implemented more preferably as an adjustable and the actual embodiments with the temperature of the fluidized bed of the combustion zone.

[0009]

As described above, the incinerator according to the present invention comprises (1)
(2) means for extracting unburned solids from the pyrolysis zone to separate unburnable combustibles from incombustibles, )
A combustion zone for burning the separated unburned combustibles, and (4) a clean for burning the combustible gas separated in the pyrolysis zone and the remaining combustible components in the combustion gas generated from the combustion zone in the presence of sufficient air. And a combustion zone.
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 and unburned combustibles such as unburned carbon, but are thermally decomposed in a reducing atmosphere. Metals such as iron and aluminum are hardly oxidized, and these metals can be recovered as valuables by means of separating unburned combustibles and incombustibles.

[0011] Further, since the unburned combustibles separated are burned independently in the combustion zone, uniform combustion is possible, and the combustion gas is finally finally discharged in the clean combustion zone in the presence of sufficient air. Therefore, the generation of harmful gases such as nitrogen oxides and dioxins is extremely small. In this way, it is possible to incinerate garbage containing no foreign matter and garbage containing foreign matter without discrimination, while minimizing the generation of harmful gases such as nitrogen oxides, dioxins, and carbon monoxide. In addition, uniform combustion is possible by dividing the incineration of waste into a pyrolysis zone and a combustion zone, and the combustion mode is pyrolysis combustion, which requires less air and reduces the amount of combustion air. It is also possible to reduce the amount of exhaust gas.

[0012] in which incinerator is equipped waste individually fluidized bed unit for burning the unburned combustibles in the combustion zone and the heating decomposed fluidized bed unit in a reducing atmosphere in the pyrolysis zone Therefore, the thermal decomposition or combustion of the unburned combustibles is independently and efficiently performed, and the unburned combustibles obtained in the pyrolysis zone are finely crushed and supplied to the combustion zone. The combustion of unburned combustibles in the furnace is performed very uniformly, which is a significant advantage in preventing generation of harmful gas. 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.

[0013] Further, the prior SL and the fluidized bed portion of the pyrolysis zone and the fluidized bed of the combustion zone is disposed adjacent through a partition wall, level the pyrolysis zone of the fluidized sand in the combustion zone The fluidized sand in the combustion zone overflows the partition walls and can move in the direction of the fluidized bed portion of the pyrolysis zone. Therefore, no power is required, and the flow power of the flowing sand in the entire apparatus can be reduced.

[0014] Before SL since disposed heat exchange pipe for circulating the heat recovery fluid to the moving bed unit which the fluidized sand is formed to move to the pyrolysis zone from the combustion zone, the temperature of the fluidized sand while achieving heat recovery To control the temperature, for example, by suppressing overheating of the pyrolysis zone. Further, since the moving bed portion is filled with the fluidized sand moving from the above combustion zone where no corrosive component such as chlorine is present, there is no possibility that the heat exchange pipe is corroded.

Further, prior SL by a partition wall provided on at least one side of the fluidized bed of the combustion zone, moving bed unit which the fluidized sand is refluxed with moves downward overflows from the fluidized bed section to the fluidized bed unit And a heat exchange pipe for circulating the heat recovery fluid in the moving bed portion, so that the boiler operated under high temperature and high pressure without being affected by corrosive components such as chlorine as described above. For example, it can be used as a heat source for a super heater, and can stably recover heat over a long period of time.

[0016]

[0017]

Next, the present invention will be described in detail with reference to the embodiments shown in FIGS. First, referring to FIG. 1, an incinerator 1 according to the present invention is constructed from a metal frame 11 lined with refractory bricks or irregular refractories, in which a pyrolysis zone 2, a combustion zone 3 and a clean combustion zone are provided. A zone 4 is formed, and an incombustible substance separation device 5 is provided.

First, the pyrolysis zone 2 is a zone defined below the incinerator 1 and adjacent to a combustion zone 3 described later. The bottom surface of the pyrolysis zone 2 is constituted by an inclined dispersion plate 22, and a window for supplying primary air is provided. Box 23 is directly connected. Fluid sand is filled on the inclined dispersing plate 22 and circulates in the opposite direction to the clock hand by the supply air from the wind box 23 (in FIG. 1).
1 are formed. An unburned solid material outlet 24 is provided at the lowermost portion of the bottom surface, and communicates with an incombustible material separation device 5 described later. The upper space of the pyrolysis zone 2 communicates with the upper space of the adjacent combustion zone 3, and on the side of the pyrolysis zone 2, an inlet 25 and a burner 26 for a waste to be incinerated are provided. ing.

The operation of the pyrolysis zone 2 formed as described above will be described. First, the fluidized sand in the fluidized bed section 21 has an average flow velocity of 0.3 to 2 m / s, preferably 0.3 m / s.
To 0.6 m / s at a temperature of 350 to 650 ° C, preferably 550 to 600 ° C, and a fluidized bed 21 having a slow flow rate. 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, the amount of supplied air is controlled to reduce the waste in a reducing atmosphere. It is important to decompose under heat. The combustible gas generated flows into the upper space of the adjacent combustion zone 3 from the upper space, and the unburned solid matter separated from the combustible gas is discharged from the outlet 24 together with the fluidized sand and the non-combustible material attached to the outside. It is sent to the sorting device 5. 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 is not included.

Next, the incombustibles separation apparatus 5 separates the uncombustible solids discharged from the outlet 24 into a group of inorganic incombustibles mainly containing metallic substances and unburned solids such as unburned carbon by particle size sorting and magnetic force sorting. Separate into combustible and liquid sand 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 unburned combustible materials such as unburned carbon and liquid sand thus separated is transferred from the incombustible material separation device 5 to a combustion zone 3 described later.

Next, a combustion zone 3 for burning unburned combustibles is a zone defined below the incinerator 1 and adjacent to the above-mentioned pyrolysis zone 2, and a fluidized bed 31 is provided below the center thereof. A moving layer 32 is provided on both sides, and an upper space 33 is provided above the moving layer 32. In the fluidized bed section 31 partitioned by the side wall 34, the unburned combustibles such as unburned carbon and the supply of the liquid sand are supplied from the incombustibles separation apparatus 5,
A fluidized bed section 31 is formed in which the unburned combustibles are burned by the primary air ejected from the dispersion pipe 35. In addition, in the upper space 33, as described above, the decomposition gas is received from the thermal decomposition zone 2 and uniform gas combustion is performed. In the fluidized bed section 31 of the combustion zone 3, the fluidized sand has an average flow velocity of 0.3 to 2.0 m / s, preferably 1.
It becomes a rapid fluidized bed at a relatively high temperature of 0 to 1.5 m / s and a temperature of 700 to 900 ° C., preferably 800 to 850 ° C., and can burn granular unburned combustibles at a high temperature and uniformly. Becomes

Partition walls 34, 34 are provided on both sides of the fluidized bed portion 31 of the combustion zone 3 so that fluidized sand overflows from the fluidized bed portion 31 and moves downward to return to the original fluidized bed portion 31. A recirculating moving bed portion 32 is formed, and a heat exchange pipe 36 for circulating a heat recovery fluid is provided in the moving bed portion 32. With such a configuration, heat can be recovered, and the temperature of the fluidized bed 31 can be adjusted. In this case, since the corrosive gas such as chlorine gas is not generated from the combustion in the combustion zone 3, stable heat exchange can be performed for a long time.

The fluidized bed 31 of the combustion zone 3 and the fluidized bed 21 of the pyrolysis zone 2 are partitioned by partitions 34, 37.
And the level of fluidized sand in the combustion zone 3 is higher than the level of fluidized sand in the pyrolysis zone 2. In this case, since the fluidized sand in the combustion zone 3 is rapidly bubbling, it overflows the partition walls 34 and 37 and moves in the direction of the fluidized bed 21 of the pyrolysis zone 2. The heat is transferred from the thermal decomposition zone 3 to the pyrolysis zone 2, and the amount of the fluidized sand in each of the zones 2 and 3 is naturally balanced and the operation is continued. Furthermore, since the power for the above-mentioned movement of the fluid sand is not required, the power for transporting the fluid sand as the whole apparatus can be reduced.

Further, the fluidized sand which overflows the partition wall 37 and moves in the direction of the fluidized bed portion 21 of the pyrolysis zone 2 forms a downward moving bed portion 39 between the partition wall 37 and the partition wall 38. A heat exchange pipe 40 for circulating a heat recovery fluid is provided in the moving bed portion 39. With such a configuration, heat can be recovered, and the temperature of the fluidized bed 21 can be adjusted. Also in this case, stable heat exchange can be performed for a long period of time because corrosive gas such as chlorine gas does not exist in the moving layer portion 39.

Further, the clean combustion zone 4 is a zone continuously partitioned above the incinerator 1 into an upper space 33 of the combustion zone 3 described later, and is a space provided with an exhaust gas outlet 41 above. ing. In the clean combustion zone 4, the combustible gas generated in the pyrolysis zone 2 and the combustible components flowing from the combustion zone 3 are finally burned at a high temperature of 800 to 900 ° C in the presence of sufficient air. For this purpose, a secondary or tertiary air supply device or a cooling water blowing device (neither is shown) is provided at an appropriate position. In this way, high-temperature and uniform gas combustion is possible in the clean combustion zone 4, and the exhaust gas is discharged from the incinerator 1 as containing no harmful gas such as nitrogen oxides, dioxins, or carbon monoxide. You can do it.

In this embodiment, the incineration of waste is divided into a pyrolysis zone 2 for decomposing waste, a combustion zone 3 for burning unburned carbon, and a free combustion zone 4 for performing gas combustion to thereby 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.

[0027]

[0028]

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, according to the embodiment, the metal in the waste is recovered as a valuable resource, the transfer power of the fluidized sand is reduced, and the heat exchange is performed in the moving bed portion of the combustion zone and the moving bed portion from the combustion zone to the pyrolysis zone. Temperature control of the fluidized bed
It is Ru can performed, have excellent effects such as to facilitate the size of the apparatus in accordance with the exhaust gas of the total amount can be reduced, or the required processing power. 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 conceptual sectional view showing an embodiment of the present invention.

FIG. 2 is an XX ′ cut horizontal sectional conceptual view of an embodiment of the present invention.

FIG. 3 is a conceptual diagram of a conventional two-stage fluidized bed incinerator.

[Explanation of symbols]

1 incinerator, 2 pyrolysis zone, 21 fluidized bed, 3
Combustion zone, 31 fluidized bed section, 4 clean combustion zone, 5 incombustible substance separation device.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toko Taka ▼ 2-56 Sudacho, Mizuho-ku, Nagoya City, Aichi Prefecture Inside Nihon Insulators Co., Ltd. No. 2 56 Inside Nippon Insulators Co., Ltd. (56) References JP-A-7-301411 (JP, A) JP-A-51-63576 (JP, A) JP-A-64-79504 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) F23G 5/027 ZAB F23G 7/12 ZAB

Claims (2)

(57) [Claims] (1) a pyrolysis zone having a fluidized bed for separating a combustible gas by thermally decomposing waste in a reducing atmosphere; and (2) extracting unburned solids from the pyrolysis zone to obtain unburned fuel. Means for separating combustibles and incombustibles, (3) a combustion zone having a fluidized bed for burning the separated unburned combustibles, and (4) a combustible gas separated from the pyrolysis zone and generated from the combustion zone. or residual combustibles in the combustion gases to a clean combustion zone for burning in the presence of sufficient air
The fluidized bed of the combustion zone and the flow of the pyrolysis zone
The moving bed and the floor are arranged adjacent to each other via a partition wall,
The level of fluidized sand in the combustion zone is
The flow of the combustion zone is located higher than the level of
The moving sand overflows the bulkhead and the pyrolysis zone
To the fluidized bed section of the
Along and below the inner wall of the pyrolysis zone
The heat recovery fluid flows through the moving bed formed toward
A fluidized bed section of said pyrolysis zone
A waste incineration apparatus including an incinerator, wherein the temperature of the waste is adjustable . 2. A partition provided on at least one side of the fluidized bed portion of the combustion zone, in which fluidized sand overflows from the fluidized bed portion, moves downward, and returns to the original fluidized bed portion. to form a layer unit, is arranged a heat exchange pipe that circulates the heat recovery fluid into the moving layer portion, the combustion
The waste incinerator according to claim 1, wherein the temperature of the fluidized bed of the zone is adjustable .