JPH11316010A - Incinerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an incinerator which can secure the quantity of oxygen required for incineration while air is supplied by the quantity required for fluidizing a material constituting a fluidized bed and, at the same time, from which the heat in the exhaust combustion gas can be utilized effectively. SOLUTION: A combustion chamber in which an object G to be incinerated is fluidized and incinerated is connected to an air chamber 4 through a thermal decomposition pipeline 20 so as to return part of the exhaust combustion gas generated in the combustion chamber to the air chamber 4. In addition, the object G' to be incinerated is thermally decomposed in the pipeline 20 in an anoxic state and supplied to the combustion chamber of the main body 1 of a fluidized bed incinerator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an incinerator body provided with incinerator material supply means, and an air dispersion provided inside the incinerator body. Relates to incinerators that are selected for the combustion chamber that burns the incinerated material and the air chamber that supplies air to the incinerated material at the bottom, and is not particularly limited, but is emitted from households, factories, etc. The present invention relates to an incinerator suitable for incineration of sludge such as sewage sludge and liquid marc in the food industry or the pharmaceutical industry, as well as general garbage.

[0002]

2. Description of the Related Art Organic waste is partially treated biologically or physically and used as fertilizers, but most of it is incinerated. Such incinerators or incinerators for incinerating organic waste are well known without mentioning any literature name, and rotary kiln incinerators, fluidized bed incinerators and the like are known. As shown in FIG. 3, the fluidized bed incinerator generally includes an incinerator 60, an air dispersion plate 61 disposed inside the incinerator 60, and an air dispersion plate 61 above the air dispersion plate 61. It is composed of a contained fluidized bed constituent material such as refractory powder M. The lower part of the air dispersion plate 61 is an air chamber 62, and the upper space of the refractory powder M is a free board part 63. The flue gas is exhausted from the free board 63, at which time heat is recovered. The discharged combustion exhaust gas is cooled and removed by a dust removal device, and then released into the atmosphere.

Since the conventional fluidized bed incinerator is configured as described above, when air is blown from the air chamber 62 into the refractory powder M through the air distribution plate 61 by the blower fan 66, a fixed layer is formed. The refractory powder M that has been turned into a fluidized bed that moves like a boiling state. Then, when the incinerated material is supplied from the hopper 64, the material is heated by the heated refractory powder M, and the emission of volatile components is started. The volatile components are burned immediately above the air distribution plate 61, and the nitrogen oxide concentration increases with the burning. Solid combustibles are burned in the particulate rich phase. Then, the generated gas reaches the free board unit 63. In the free board section 63, secondary combustion of unburned components, concentration control of nitrogen oxides, and the like are performed by the secondary air supplied from the secondary air supply pipe 65. In addition, incineration is performed in a similar manner by an incinerator provided with a rostelle instead of a fluidized bed.

[0004]

According to the above-mentioned conventional fluidized bed incinerator, the fluidized fluidized bed constituent material acts as a heat storage medium, and the fluidized bed constituent material comes into good contact with sludge, so that combustion is promoted. In addition, there is an advantage that incombustible materials such as sludge which are difficult to burn are efficiently incinerated. However, there are disadvantages or points to be improved.
That is, in order to efficiently perform fluidized bed incineration, it is necessary to keep the fluidized bed constituent material in a fluidized state by the air supplied to the air chamber, but oxygen in the air necessary for maintaining the fluidized state is not necessarily burned. The amount of oxygen is not necessary for the amount, so that the amount of oxygen may be excessive or insufficient. In other words, since the fluidization start flow velocity is determined by the particle size, specific gravity, etc. of the fluidized bed constituent material, in the conventional fluidized bed incinerator, it is necessary to burn at the oxygen concentration in the determined air amount. . Also, incinerated materials containing a large amount of water are dehydrated,
Combustion cannot be performed unless pretreatment such as thermal decomposition is performed, and there is a disadvantage that a pretreatment device is separately required. Furthermore, the heat in the flue gas is not effectively used.

[0005] Such disadvantages are also true of incinerators provided with a grate instead of a fluidized bed. For example, air supplied to the air chamber below the grate enters into the incineration above the grate, and the incineration must be dispersed to each other in a state necessary for combustion. The air does not always contain the amount of oxygen necessary for combustion. Also,
Similarly, the heat in the flue gas is not effectively utilized.
An object of the present invention is to provide an incinerator that has solved the above-mentioned conventional disadvantages. Specifically, the present invention is also directed to supplying an air amount necessary for flowing a fluidized bed constituent material or dispersing an incinerated material. Regardless, an object of the present invention is to provide an incinerator in which the amount of oxygen necessary for combustion is secured. It is another object of the present invention to provide an incinerator in which heat in flue gas is effectively used. Another object of the present invention is to provide an incinerator capable of performing inexpensive pretreatment in addition to the above objects.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an incinerator body provided with incinerator material supply means, and an air dispersion body provided inside the incinerator body. An incinerator wherein the upper part of the air dispersion is selected as a combustion chamber for burning the incineration material, and the lower part is selected as an air chamber for supplying air to the incineration substance, wherein the air chamber An air supply pipe is opened, and a return pipe is provided between the combustion chamber of the incinerator main body and the air chamber so that a part of the combustion exhaust gas is returned to the air chamber. The air is supplied from the air supply pipe to the chamber and the combustion exhaust gas returned from the return pipe is supplied at a controlled ratio. The invention described in claim 2 is
The return pipe according to the first aspect is provided with a transporting means for transporting the incinerated material to the combustion chamber inside the return pipe. The invention according to the third aspect is characterized in that the air dispersion according to the first or second aspect includes , A fluidized bed composed of an air dispersion plate and a fluidized bed constituent material stored above the air dispersion plate. The invention according to claim 4 includes an incinerator main body provided with incinerator material supply means,
An air disperser provided inside the incinerator main body, an upper portion of the air disperser serving as a combustion chamber for burning the incineration material, and a lower portion providing an air supply for the incinerator material. A first incineration section selected in the above, an incinerator main body, and an air dispersion provided inside the incinerator main body, the upper part of the air dispersion burns the incinerated material. And a second incineration section whose lower part is selected as an air chamber for supplying air to the incineration material. An air supply pipe is opened in the air chamber of the second incineration section. In addition, the other end of the exhaust gas supply pipe having one end connected to the combustion chamber of the first incinerator main body is open. According to a fifth aspect of the present invention, the exhaust gas supply pipe according to the fourth aspect is provided with a transporting means for transporting the incinerated material to the combustion chamber of the first combustion section inside the exhaust gas supply pipe. According to the invention described in the above, the air dispersion according to the fourth or fifth aspect is configured as a fluidized bed including an air distribution plate and a fluidized bed constituent material stored above the air dispersion plate.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is applicable to various types of incinerators.
An embodiment will be described. As shown in FIG. 1, the fluidized bed incinerator according to the first embodiment includes an incinerator 1 made of a firebrick or the like.
An air distribution plate 2 having a conventionally well-known form is provided inside the lower part of the incinerator, and a fluidized bed constituent material M is stored above the air distribution plate 2. Fluidized bed constituent material M
For example, refractory powders such as silica sand and lime can be used, but Ba, which exhibits an oxidation catalytic action like platinum, can be used.
O.6Al2O3, SrO.6Al2O3, CaO.6A
l2O3, MgAl2O4 + α, ZrO2 + α, K2O
At least one of 11Al2O3 and La2O3.11Al2O3 can be selected. By using the fluidized bed constituent material M having such an oxidation catalytic action, low-temperature combustion can be performed, and the life of the incinerator 1 is extended.

Below the air distribution plate 2 is an air chamber 4.
An air supply pipe 6 for forcibly supplying air to the air chamber 4 is open. The air supply pipe 6 is provided with a first blower 8 driven by a motor 7, and the amount of air supplied to the air chamber 4 is controlled by a control device 10 as described later. . The upper space of the fluidized-bed constituent material M becomes a free board section 15 and the free board section 1
As is well known in the art, a part of the combustion exhaust gas is discharged to the atmosphere via a dust collector or the like. A first supply pipe 16 for supplying the incinerator 1 with a normal incineration object G that does not require pretreatment is opened at a position above the fluidized-bed constituent material M of the incinerator 1. The first supply pipe 16 is provided with a first hopper 18 in which the incineration material G is temporarily stored via a mechanical feeder 17 such as a rotary or a screw. A secondary air supply pipe 19 is opened at a position of the incinerator 1 corresponding to the free board section 15. By the air supplied from the secondary air supply pipe 19, combustion of unburned components, concentration control of nitrogen oxides, and the like are performed.

According to the present embodiment, the incinerator 1 is provided with the return pipe 20. The return pipe 20 returns a part of the combustion exhaust gas to the air chamber 4, and has a relatively large-diameter pyrolysis pipe 21 and a relatively small-diameter return pipe connected to the pyrolysis pipe 21. 22. The starting end of the pyrolysis pipe 21 opens at a position above the fluidized-bed constituent material M and below the freeboard portion 15 of the incinerator 2, and the end of the return pipe 22 is connected to the air chamber 4. It is open. Therefore, a part of the high-temperature combustion exhaust gas including the unburned gas is returned to the air chamber 4 by the return pipe 20.

[0010] In the present embodiment, the pyrolysis pipe 21 of the return pipe 20 is disposed on an ascending slope, and supplies an incinerated material G 'which requires pretreatment such as dehydration and pyrolysis to the upper end thereof. Supply pipe 25 is open. And this second
A second hopper 27 for temporarily storing the incineration material G ′ is connected to an upper end of the supply pipe 25 through a mechanical feeder 26 such as a rotary or a screw. Since the second hopper 27 is connected to the second supply pipe 25 via the mechanical feeder 26 in this manner, the inside of the thermal decomposition pipe section 21 is sucked by the second blower 23 described later. Therefore, the combustion exhaust gas does not leak to the second hopper 27. An endless transfer device 28 made of a heat-resistant material such as a chain conveyor or a scraper that reaches the inside of the incinerator 1 from below the opening of the second supply pipe 25 is provided inside the pyrolysis pipe 21. Have been. As a result, the incineration material G ′ supplied from the second hopper 27 is supplied to the incinerator 1 while undergoing heat treatment in the pyrolysis pipeline 21.

The return pipe 22 of the return pipe 20 is provided with a second blower 23 driven by a motor 24.
, The amount of air blown by the blower 23 is controlled by the control device 10. In addition, the air supplied from the air supply pipe 6 and the return pipe 20 are provided in the air chamber 4.
A baffle plate 5 is provided for uniformly mixing the combustion exhaust gas supplied from the apparatus.

Next, the operation of the fluidized bed incinerator will be described. When incinerating a normal incineration object G that does not require pretreatment such as dehydration and thermal decomposition, the mechanical feeder 26 of the second hopper 27 is stopped, and the incineration object G is only applied to the first hopper 18. To accommodate. The first and second blowers 8, 23 are started. Then, air is supplied to the air chamber 4 by the air supply pipe 6. A part of the high temperature combustion exhaust gas is supplied to the air chamber 4 by the return pipe 20. In the air chamber 4, the air and the high-temperature combustion exhaust gas are uniformly mixed by the baffle plate 5 and supplied from the air dispersion plate 2 into the incinerator 1. Thereby, the fluidized bed constituent material M having a fixed bed
Becomes a fluidized bed that moves like a boiling state. The mechanical feeder 17 is started, and the incineration material is supplied from the first hopper 18 to the incinerator 1. The incinerator burns as is well known in the art. In the free board unit 15, unburned components are burned by air supplied from the secondary air supply pipe 19, and the concentration of nitrogen oxides is controlled. Then, the combustion exhaust gas filtered by the dust collector or the like is released to the atmosphere.

As described above, when the incinerated material G burns, the motor 7 of the first blower 8 is controlled by the control device 10 to supply the air containing the amount of oxygen necessary for combustion. Supply air containing the amount of oxygen necessary for combustion and return pipe 2
The total amount of flue gas supplied from 0 is fluidized bed constituent material M
The control device 10 controls the motor 24 of the second blower 23 so that the mixed air amount necessary for fluidizing the air is obtained. As a result, a sufficient amount of oxygen required for combustion and a sufficient amount of mixed air required for fluidization are obtained, and ideal combustion is performed by the preheated mixed air.

When incinerating the incinerated material G 'which needs to be subjected to a pretreatment such as dehydration or thermal decomposition, the first hopper 18 is closed and the second hopper 27 is connected to the pyrolysis tube of the return pipe 20. It is supplied to the road 21. Further, the endless transfer device 30 is started. Then, the incinerated material G ′ is transported in the pyrolysis pipeline 21 over time and supplied to the incinerator 1. At this time, since the incinerated material G 'is transported in the high-temperature, oxygen-free combustion exhaust gas, it undergoes pretreatment such as dehydration and thermal decomposition.
Methane, acetone, water vapor and the like generated by the thermal decomposition are supplied to the air chamber 4 together with the combustion exhaust gas. Then, it is burned in the incinerator 1 together with the incineration material G 'as described above.

In the first embodiment, the ordinary incineration object G is supplied from the first hopper 18 with the second hopper 27 closed, and the incineration object requiring pretreatment is required. The object G ′ closes the first hopper 18 and closes the second hopper 2.
7, it has been described that they are supplied separately. However, it is apparent that the first and second hoppers 18 and 27 can supply them simultaneously. It is also clear that ordinary incineration material G can be supplied from the second hopper 27. Further, the present invention can be similarly applied to an incinerator having a grate instead of a fluidized bed. That is, the incinerator equipped with a grate also has an amount of oxygen necessary for combustion, and an amount of mixed air required for dispersing the incineration materials G and G ′ supplied on the grate. By controlling the first and second blowers 8, 23, ideal combustion is performed.

Next, a second embodiment of the present invention will be described with reference to FIG. Although the second embodiment can also be implemented in an incinerator equipped with a grate, an example in which the invention is implemented in a fluidized bed incinerator will be described. The incinerator according to the second embodiment is roughly composed of a first incinerator 30 and a second incinerator 50 dedicated to gas, and the first and second incinerators 30, 50 are connected by a pyrolysis line 40.

The first incinerator 30 includes an incinerator 31 made of a material such as refractory brick, and a conventionally well-known air distribution plate 32 is provided below the incinerator 31. Above the air distribution plate 32, the fluidized-bed constituent material M as described above is stored. Air distribution plate 32
Below the air chamber 34 is an air chamber 34, and an air supply pipe 35 for forcibly supplying air required for combustion and fluidization to the air chamber 34 by a first blower 36 is opened. According to the present embodiment, there is no free board part, and the first incinerator 3
1, a first supply pipe 37 for supplying a normal incineration material G is opened at a position above the fluidized-bed constituent material M. The first supply pipe 36 is also provided with a first hopper 39 via a mechanical feeder 38.

The second incinerator 50 is also used as the first incinerator 3
An incinerator 51 similar to the incinerator 51 is provided, and an air distribution plate 52 is provided inside the incinerator 51 below. Above the air distribution plate 52, the fluidized-bed constituent material M as described above is stored. An air chamber 54 is provided below the air distribution plate 52, and an air supply pipe 56 for forcibly supplying air to the air chamber 54 is open. This air supply pipe 56
Also, a second blower 57 driven by a motor 58 is provided. The amount of air supplied to the air chamber 54 is also controlled by the control device 59. The air chamber 54 also has an open gas supply pipe 55 to which the combustion exhaust gas of the first incinerator 30 and the pyrolysis gas of the incineration object G 'requiring pretreatment are supplied. The incinerator 51 also has no free board portion, and the combustion exhaust gas is directly filtered by a bag filter or the like and released to the atmosphere. In the air chamber 54, a baffle plate 53 is similarly provided.

The upper part of the incinerator 31 of the first incinerator 30 and one end of the gas supply pipe 55 are connected by the pyrolysis conduit 40 of the incinerator 31. Further, a second supply pipe 43 for supplying the incineration object G 'requiring pretreatment is opened in the upper part of the pyrolysis pipe 40 in the same manner as in the first embodiment. doing. At the upper end of the second supply pipe 43, a second hopper 45 for temporarily storing the incineration object G 'via a mechanical feeder 44 such as a rotary or screw is provided. A heat-resistant endless conveyor 42 such as a chain conveyor or a scraper that reaches the inside of the first incinerator 31 from below the opening of the second supply pipe 42 is provided inside the pyrolysis pipe 40. I have. As a result, the incineration material G ′ supplied from the second hopper 27 is supplied to the first incinerator 31 through the pyrolysis pipeline 40.

Next, the operation of the second embodiment will be described. The normal incineration material G is supplied from the first hopper 38 to the incinerator 31 of the first incinerator 30. Also, if necessary, the endless transporter 42 is driven,
Incineration object G 'requiring pretreatment from second hopper 44
Alternatively, a normal incineration material G is supplied. Then, the first and second blowers 36 and 57 are started. Then, in the first incinerator 30, the incinerated material G and the thermally decomposed incinerated material G 'are burned in a known manner. The combustion exhaust gas and the unburned gas are supplied from the pyrolysis pipeline 40 to the air chamber 54 of the second incinerator 50. At this time, decomposition gas such as methane, acetone, and water vapor decomposed in the pyrolysis pipe 40 is also supplied to the air chamber 54. Air chamber 54
Is supplied with a controlled amount of air from an air supply pipe 56, is uniformly mixed by a baffle plate 53, and
2 into the fluidized bed constituent material M. This allows
The unburned gas and the decomposed gas burn in a known manner.

The second embodiment can be variously modified. For example, the first and second incinerators 30 and 50 may be implemented by an incinerator equipped with a grate instead of the fluidized bed incinerator for the above-described reason. At this time,
It is also clear that this can be carried out by combining a fluidized bed incinerator with a grate equipped incinerator. In addition, the second
In the embodiment, since the entire amount of the combustion exhaust gas generated in the first incinerator 30 is supplied to the air chamber 54 of the second incinerator 50, the air is supplied from the air supply pipe 56. Even if only the amount of air is controlled, it may be difficult to achieve ideal combustion and ideal fluidization of the fluidized-bed constituent material M. Therefore, as shown by a chain line in FIG.
The branch pipe 55 ′ may be branched from the gas supply pipe 55 so that the excess flue gas is discharged to the free board portion of the second incinerator 50. Alternatively, the branch pipe 55 'can be connected to the air chamber 34 of the first incinerator 30. Also at this time, as in the first embodiment, the supply air amount including the oxygen amount necessary for combustion,
Control is performed so that the total amount of the combustion exhaust gas supplied from the thermal decomposition pipe becomes the mixed air amount necessary for fluidizing the fluidized bed constituent material M. In the second embodiment, the second incinerator 50 is a gas-only incinerator.
It is clear that the incinerator 50 can incinerate unburned gas and solid waste, and also solid waste together with unburned gas and pyrolysis gas.

[0022]

As described above, according to the present invention, the incinerator main body provided with the incinerator material supply means and the air dispersion body provided inside the incinerator main body are provided. The upper part of the body is selected as a combustion chamber for burning the incineration material, and the lower part is selected as an air chamber for supplying air to the incineration material,
And in the air chamber, air supplied from the air supply pipe,
Since the flue gas returned from the return pipe is configured to be supplied at a controlled ratio, a sufficient amount of oxygen required for combustion and a sufficient mixed air required for fluidization or dispersion are provided. The quantity and the preheated mixed air provide ideal combustion. According to the second aspect of the present invention, since the return pipe is provided with a transporting means for transporting the incinerated material to the combustion chamber therein, the incinerated material is heated in an oxygen-free state during the transport process. Then, the incinerator which is decomposed into methane, acetone, water vapor and the like and hardly burns is effectively incinerated. At this time, since the pretreatment is performed with the combustion exhaust gas, no special energy is required for the pretreatment.
Therefore, the effect of being inexpensive and making the device compact can be obtained. According to the third aspect of the present invention, since the air dispersion is configured as a fluidized bed composed of the air dispersion plate and the fluidized bed constituent material stored above the air dispersion plate, sludge such as sewage sludge is also included. Can be incinerated effectively. According to the invention as set forth in claim 4, the first incineration unit provided with the incineration material supply means and the second incineration unit are provided, and the air chamber of the second incineration unit is provided with an air supply pipe. Is open, and the other end of the exhaust gas supply pipe, one end of which is connected to the combustion chamber of the first incinerator main body, is open. Therefore, in the second incineration section, the first incineration section The unburned gas generated in the above is burned more completely, and if necessary, the solid incineration material can be incinerated by effectively utilizing the combustion exhaust gas of the first incineration section. According to the fifth aspect of the present invention, in the exhaust gas supply pipe that guides the combustion exhaust gas of the first incineration section to the air chamber of the second incineration section, the incineration material is provided therein with the combustion chamber of the first combustion section. Is provided, the effect of pretreating the incinerated materials that are difficult to burn in an oxygen-free state is added. According to the invention as set forth in claim 6, the air dispersion body is an air dispersion plate. When,
Since it is configured as a fluidized bed composed of a fluidized bed constituent material stored above the sludge, sludge such as sewage sludge can be effectively incinerated together with unburned gas.

[Brief description of the drawings]

FIG. 1 is a front view schematically showing a first embodiment of the present invention in a partial cross section.

FIG. 2 is a front view schematically showing a second embodiment of the present invention in a partial cross section.

FIG. 3 is a front view schematically showing a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Combustion furnace 2 Air dispersion plate 4 Air chamber 6 Air supply pipe 8 First blower 20 Return pipe 21 Thermal decomposition line 23 Second blower 28 Carrier 30 First incinerator 31 Incinerator 32 Air dispersion plate 36 First 1 blower 40 pyrolysis pipeline 42 conveyor 50 second incinerator 51 incinerator 52 air dispersion plate 54 air chamber 57 second blower M fluidized bed constituent material G, G '

Claims (6)

[Claims] A means for supplying incinerated materials (16, 17, 18)
And an air dispersion body (2) provided inside the incinerator body (1), the upper part of the air dispersion body (2) being incinerated. Object (G)
An incinerator selected as a combustion chamber for burning air and an air chamber (4) for supplying air to the incineration material (G) at a lower portion, wherein an air supply pipe is provided in the air chamber (4). (6) is open, and a part of the combustion exhaust gas is provided between the combustion chamber of the incinerator body (1) and the air chamber (4).
A return pipe (20) is provided for returning the air supplied from the air supply pipe (6) and the combustion exhaust gas returned from the return pipe (20) to the air chamber (4). Is supplied in a controlled manner. 2. The incinerator according to claim 1, wherein the return pipe (20) according to claim 1 is provided with a transport means (28) for transporting the incinerated material (G ′) to the combustion chamber. 3. An incinerator wherein the air dispersion according to claim 1 or 2 is a fluidized bed comprising an air dispersion plate (2) and a fluid bed constituent material (M) stored above the air dispersion plate. 4. An incinerated material supply means (37, 38, 39)
And an air dispersion body (32) provided inside the incinerator body (31). The upper part of the air dispersion body (32) is incinerated. Incineration as well as the first incineration section (30), which is selected for the combustion chamber for burning the object (G) and for the lower part of the air chamber (34) for supplying air to the incineration (G '). Furnace body (5
1) and an air dispersion (52) provided inside the incinerator body (51).
A second incineration section (50) whose upper part is selected as a combustion chamber for burning the incineration material and whose lower part is an air chamber (54) for supplying air to the incineration material, An air supply pipe (56) is open to the air chamber (54) of the second incinerator (50), and one end is connected to the combustion chamber of the first incinerator body (31). The incinerator characterized in that the other end of the exhaust gas supply pipe (40) is open. 5. The exhaust gas supply pipe (40) according to claim 4,
The incineration material (G ′) is contained in the first combustion section (3).
0) An incinerator provided with a conveying means (42) for conveying to the combustion chamber. 6. An incineration, wherein the air dispersion according to claim 4 or 5 is a fluidized bed comprising an air dispersion plate (32, 52) and a fluidized bed constituent material (M) stored above the air dispersion plate. apparatus.