JP2006105431A - Stoker type incinerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the decomposition of dioxins in incinerated ash and the elution of heavy metals from the incinerated ash and to prevent the burning of a fire grate of a stoker. <P>SOLUTION: In the stoker type incinerator, primary combustion air A is dividedly supplied down to the stoker 9 divided into a plurality of parts in the flowing direction of wastes W for drying, burning and delay-burning, in sequence, the wastes W on the stoker 9 to form the incinerated ash D which is discharged from an ash outlet 7a located on the downstream side of the stoker 9. A grain size sorting machine 19 is arranged on the downstream side of the ash outlet 7a for sorting the incinerated ash D discharged from the ash outlet 7a into coarse grain ash Da and small grain ash Db on a grain-size base. The sorted small grain ash Db is recharged into the incinerator together with the wastes W. Oxygen O is mixed into the primary combustion air A supplied from a main combustion center down to the stoker 9b located at a burnout point, out of the stoker 9 divided into the plurality of parts, to form oxygen enriched air A'. The stoker 9b to which the oxygen enriched air A' is supplied is made to be a water cooled structure. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a stoker-type incinerator for incinerating waste such as municipal waste and industrial waste. Decomposition of dioxins in incineration ash, prevention of elution of heavy metals from incineration ash, and grate forming stoker In particular, the present invention relates to a stoker-type incinerator capable of preventing burnout of a grate when incinerating a waste having a low ash content and a high calorific value.

  Incineration ash, fly ash, etc. discharged from waste incinerators (stoker-type incinerators, fluidized-bed incinerators, etc.) that incinerate waste such as municipal waste in recent years due to tightness of final disposal sites such as landfills As a processing method for reducing and detoxifying the incineration residue and effectively using it, a melting method for incineration residue is widely used. This is because the above processing method can significantly reduce the volume of the incineration residue such as incineration ash by melting, prevent the elution of harmful substances such as heavy metals, reuse of the molten slag, and the final disposal site. This is because it is possible to prolong life.

  The incineration residue melting method includes recovering heat from a combustion exhaust gas generated in a waste incinerator to generate steam and supplying the steam to a steam turbine power generator to generate electricity. , A method using an electric melting furnace such as a plasma melting furnace or an arc melting furnace that heats and melts the incineration residue with heat energy obtained from the generated electricity, and incineration with the combustion heat of fossil fuels such as natural gas and oil There is a method using a fuel combustion type melting furnace such as a surface melting furnace or a swirl type melting furnace for heating and melting the residue.

FIG. 2 shows a schematic system diagram of a waste treatment plant using an electric melting furnace or a fuel combustion type melting furnace. The waste treatment plant removes waste W such as municipal waste and industrial waste from a stoker-type incinerator. The incineration residue such as incineration ash D and fly ash D ′ discharged from the stoker type incinerator 30 is melted in the melting furnace 31.
In FIG. 2, 30 is a stoker type incinerator for incinerating the waste W, 31 is a melting furnace for melting the incineration ash D and fly ash D ′, and 32 is primary combustion to the stoker 33 of the incinerator 30. A blower for supplying air A, 34 is a waste heat boiler that recovers heat from combustion exhaust gas and generates steam S, 35 is an exhaust gas treatment device that converts combustion exhaust gas into clean gas, and 36 is steam that generates electricity by steam S Turbine power generator, 37 is a pretreatment facility (crusher, sieve, magnetic separator, etc.) for removing unsuitable melting materials, iron and aluminum in incineration ash D, and 38 is an exhaust gas treatment device for treating exhaust gas discharged from melting furnace 31 , 39 is a kneading device for kneading and solidifying by adding a heavy metal stabilizer such as liquid chelate or cement to the molten fly ash D ″ from the exhaust gas treatment device 38.

  The waste treatment plant uses an electric melting furnace and a fuel combustion melting furnace, which increases equipment costs, requires considerable electric energy and combustion energy for melting the incineration residue, and processing costs are also high. There was a problem that it soared significantly. Therefore, conventionally, there is a demand for a simple incineration residue treatment method that uses less energy.

  On the other hand, in the disposal of waste such as municipal waste, incineration using a stoker-type incinerator or fluidized-bed incinerator is the mainstream. Reduction of environmental load by heat recovery is an important issue. Among them, the stoker-type incinerator has many excellent effects in terms of operational stability, economic efficiency, incineration performance, etc., and is the most popular incinerator, with low air ratio combustion technology and oxygen-rich incinerator. In recent years, advanced combustion technology has been developed and so on.

In the low air ratio combustion and oxygen-enriched combustion in the stoker type incinerator, the combustion chamber becomes hotter than the conventional combustion, and accordingly, countermeasures for the furnace structure and the stoker are required.
For example, for a furnace, the furnace wall is made into a boiler water tube structure, or silica sand or the like is introduced into the furnace to reduce the concentration of alkali metal salts such as sodium and potassium which are the main components of the clinker, thereby generating clinker. In addition, it is possible to prevent melting of refractories, etc., and to improve the air cooling effect for the stoker, and in the case of oxygen-enriched combustion that becomes high temperature in the fire bed, the stoker has a water cooling structure. The fire grate was prevented from burning out (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

The stoker-type incinerator disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2002-13716) includes an upstream post-combustion stoker supplied with oxygen-enriched air and a downstream post-combustion supplied with low-temperature air. A water-cooled post-combustion stoker with a stalker is provided, and oxygen-enriched air is supplied to the upstream post-combustion stalker to raise the temperature of the incinerated ash on the upstream post-combustion stalker to 700 ° C. to 900 ° C. By supplying low-temperature air to the side rear combustion stalker and cooling the incineration ash on the downstream side rear combustion stalker, dioxins and heavy metals in the incineration ash are reduced.
However, in this stoker-type incinerator, when incinerating miscellaneous waste, the combustion temperature is not uniform and varies, so that the incineration ash contains a high proportion of dioxins and heavy metals. There is a problem that some kind of treatment is required for the incinerated ash that is finally discharged. In addition, when incinerating special waste (plastics, etc.) with low ash content and high calorific value, there is a problem that the stoker grate cannot be sufficiently protected.

In addition, the stoker type incinerator disclosed in Patent Document 2 (Japanese Patent Application Laid-Open No. 2004-101047) measures the temperature of the grate by a temperature detector embedded in the grate of the stoker and incinerates based on this. The primary combustion air that is supplied under the stoker so that the combustion temperature of the object is predicted and the temperature of the grate falls within the range of 350 ° C. to 500 ° C. and the combustion temperature of the incinerated material falls within the range of 800 ° C. to 1100 ° C. By controlling the amount of oxygen mixed in, the temperature of primary combustion air, and the amount of primary combustion air respectively, dioxins and heavy metals in incineration ash were reduced, and burnout of the grate was prevented. Is.
However, this stoker type incinerator has the same problem as the above stoker type incinerator.

Furthermore, the stoker-type incinerator disclosed in Patent Document 3 (Japanese Patent Application Laid-Open No. 2002-333122) is a factor in producing clinker by putting a part of silica sand or incinerated ash discharged from the incinerator into the furnace. Reduce the concentration of alkali metal salts such as sodium and potassium, which are substances, to suppress the production of clinker, and to prevent clinker from adhering to the furnace wall and to remove the clinker adhering to the furnace wall due to scattered silica sand, etc. It is a thing.
However, even in this stoker-type incinerator, it is difficult to reliably reduce dioxins and heavy metals in the incineration ash and to prevent burnout of the grate. have.
JP 2002-13716 A JP 2004-101047 A JP 2002-333122 A

  The present invention has been made in view of such problems, and its purpose is to decompose dioxins in the incineration ash, prevent elution of heavy metals from the incineration ash, and prevent burnout of the grate forming the stoker. In particular, it is an object of the present invention to provide a stoker-type incinerator capable of preventing burnout of a grate when incinerating waste with low ash content and high calorific value.

  The inventors of the present application pay attention to the fact that the contents of harmful substances such as dioxins and heavy metals contained in the incineration ash differ depending on the incineration ash particle size as shown in Table 1 below. We have developed a stoker-type incinerator that can process incineration residue easily by using less energy.

  That is, according to the first aspect of the present invention, the primary combustion air is dividedly supplied to the bottom of the stoker divided in the waste flow direction, and the waste on the stoker is sequentially dried, burned, burned, and burned. In a stoker-type incinerator where the incineration ash is discharged from the ash outlet at the downstream side of the stoker, the incineration ash discharged from the ash outlet at the downstream position of the ash outlet is coarse-grained. A particle size sorter for sorting the ash and fine ash is arranged, and the fine ash selected is re-introduced into the furnace together with the waste. Oxygen is mixed with the primary combustion air supplied from the center to the stoker located at the burnout point to make the primary combustion air oxygen-enriched air, and the stoker supplied with oxygen-enriched air is a water-cooled stoker. There is a feature in doing.

  In the invention of claim 2 of the present invention, a wind power sorter for separating fine ash and unburned matter adhering to the coarse ash sorted by the particle size sorter is disposed at a downstream side position of the particle size sorter. The separated fine ash and unburned matter are characterized by being re-introduced into the furnace.

  According to the third aspect of the present invention, the temperature of the grate of the stoker to which oxygen-enriched air is supplied is detected by a temperature detector, and the amount of oxygen mixed into the primary combustion air is controlled based on the detected temperature. It is characterized by doing so.

The stoker-type incinerator according to the present invention uses the particle size sorter to convert the incineration ash discharged from the ash outlet into coarse ash having a low concentration of dioxins and heavy metals and fine ash having a high concentration of dioxins and heavy metals. Fine-grained ash with high concentrations of dioxins and heavy metals is re-introduced into the furnace together with waste, and oxygen-enriched air from the main combustion center to the stoker located at the burn-out point As the primary combustion air is supplied, the incinerated ash on the stoker can be clinkered by raising it to a temperature near the melting point at which it becomes a semi-molten state. As a result, the stoker-type incinerator according to the present invention can decompose harmful substances such as dioxins contained in the incineration ash, promote the volatilization of heavy metals, and improve the properties of the incineration ash. can do. However, the coarse ash selected from the incineration ash can be effectively used as it is because the concentrations of dioxins and heavy metals are low.
Further, the stoker type incinerator of the present invention re-injects the selected fine ash into the waste and the furnace together, and the stoker supplied with oxygen-enriched air is a water-cooled stoker. The grate can be protected by thickening the ash layer and covering the stoker with the ash layer, and the grate can be surely protected by water cooling the stoker against an increase in combustion temperature. As a result, the stoker-type incinerator of the present invention does not say that the stoker's grate is exposed to heat or excessively heated even when waste with low ash content and high calorific value is incinerated. It is possible to reliably and satisfactorily prevent burnout of the grate. As a result, maintenance costs can be reduced by burning out the grate.
Furthermore, the stoker-type incinerator of the present invention separates the fine ash and unburned matter adhering to the coarse ash selected by the particle size sorter by the wind sorter, and the separated fine ash and unburned matter is separated. Since it is made to re-inject into the furnace, the concentration of dioxins and heavy metals contained in the coarse ash can be further reduced.
In addition, the stoker type incinerator of the present invention detects the temperature of the grate of the stoker supplied with oxygen-enriched air with a temperature detector, and controls the amount of oxygen mixed with the primary combustion air based on the detected temperature. Thus, the stoker grate can be protected more reliably and better.
In addition, the stoker-type incinerator of the present invention treats the incineration ash by physical sorting using a particle size sorter or the like, so that it is possible to reduce the melting equipment such as the melting furnace, No fuel is required, and initial cost and running cost can be reduced and energy can be saved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a schematic system diagram of a waste treatment plant using a stoker-type incinerator 1 according to an embodiment of the present invention. The waste treatment plant comprises a stoker-type incinerator 1 and a waste heat boiler 2. , A steam turbine power generation device 3, an exhaust gas treatment device 4, a heating and desalination device 5, a kneading device 6 and the like, and incineration ash D by incineration of waste W such as municipal waste by a stoker incinerator 1 In addition, the decomposition of dioxins and other hazardous materials in the incineration ash D in the furnace and the volatilization of heavy metals are promoted, and the incineration ash D discharged from the furnace is processed by physical sorting to remove dioxins and heavy metals. It is taken out as coarse ash Da having a low concentration, and the fly ash D ′ in the combustion exhaust gas discharged from the furnace is recovered, and the combustion exhaust gas is made into a clean gas and released into the atmosphere.

The stoker-type incinerator 1 includes a furnace body 7, a waste supply hopper 8, a stalker 9, a hopper under a stalker 10, a pusher blower 11, a primary combustion air supply pipe 12, an air amount adjusting damper 13, an oxygen generator 14, an oxygen supply. It includes a pipe 15, an oxygen amount adjustment valve 16, a temperature detector 17, a temperature controller 18, a particle size sorter 19, a wind sorter 20, a dust collector 21, a magnetic separator 22, an aluminum sorter 23, and the like, on the downstream side of the stoker 9. The incinerated ash D discharged from the ash outlet 7a formed at the position is converted into a coarse ash Da having a low concentration of dioxins and heavy metals and a fine ash Db having a high concentration of dioxins and heavy metals by a particle size sorter 19. The fine particle ash Db is re-introduced into the furnace together with the waste W, and the fine ash Db and unburned material adhering to the coarse ash Da are separated by the wind power sorter 20. These into the furnace has to be turned on again.
In addition, the stoker type incinerator 1 mixes oxygen O with primary combustion air A supplied from the main combustion center to the bottom of the stoker point out of the plurality of stokers divided in the flow direction of the waste W. Then, the primary combustion air A is oxygen-enriched air A ′, the stalker to which the oxygen-enriched air A ′ is supplied is a water-cooled stalker, and the grate of the stalker is detected by the temperature detector 17. The amount of oxygen O supplied to the primary combustion air A is controlled based on the detected temperature.

Specifically, the stoker 9 includes a dry stoker 9a, a combustion stoker 9b, and a post-combustion stoker 9c, and a lower stoker hopper 10 is disposed below each stoker 9a, 9b, 9c. Each of these stokers 9a, 9b, and 9c is formed by combining a movable grate and a fixed grate alternately in a staircase shape or in an inclined manner as in the known art. The waste W on the stokers 9a, 9b, and 9c is advanced from the upstream side to the downstream side while being stirred by reciprocating at a constant pitch in the front-rear direction by a driving device (not shown) such as a cylinder. Yes.
Further, the lower hopper 10 of each of the dry stalker 9a, the combustion stalker 9b, and the post-combustion stalker 9c has a primary combustion air supply pipe 12 and a proximal end of the primary combustion air supply pipe 12 connected to the respective stalker lower hoppers 10 in a branched manner. An appropriate amount of primary combustion air A is supplied from the pusher blower 11 connected to the section in accordance with the supply amount and properties of the waste W. The supply amount of the primary combustion air A is adjusted by automatically or manually controlling the opening degree of the air amount adjustment damper 13 provided in the primary combustion air supply pipe 12.

  In the stoker 9, oxygen O is mixed with the primary combustion air A supplied from the main combustion center to the combustion stoker 9b located at the burn-out point to obtain oxygen-enriched air A '. The temperature of the ash layer on the combustion stoker 9b is raised so that the incinerated ash D on the combustion stoker 9b rises to a temperature near the melting point at which the incinerated ash D on the combustion stoker 9b rises to a semi-molten state. D is clinkerized. The supply of oxygen-enriched air A ′ below the combustion stoker 9b is performed by supplying an oxygen supply pipe 15 and an oxygen generator 14 (pressure fluctuation adsorption) to a primary combustion air supply pipe 12 connected in a branched manner to the hopper 10 below the stoker of the combustion stoker 9b. Separate oxygen generators) are sequentially connected, and the oxygen O generated by the oxygen generator 14 is mixed with the primary combustion air A flowing in the primary combustion air supply pipe 12.

  Further, in this stoker 9, the combustion stoker 9b to which the oxygen-enriched air A 'is supplied is a water-cooled stoker, and the movable and fixed grate of the combustion stoker 9b are used as the combustion temperature rises. We are trying to protect it. A water-cooled stalker is a water-cooled grate that has a movable grate and a fixed grate, each of which has a cooling water passage through which cooling water flows, and is connected to each fire through a water cooling device and a cooling water circulation pump (both not shown). Cooling water is circulated and circulated through the cooling water passages of the lattice to adjust the temperature of each grate. As the water-cooled stoker, those disclosed in JP-A Nos. 2002-364823 and 2003-4218 are used.

  Further, in the stoker 9, the temperature of the grate of the combustion stalker 9b to which the oxygen-enriched air A 'is supplied is monitored, and this temperature is a predetermined temperature (a temperature that can prevent the grate from being burned out). Thus, the amount of oxygen O mixed with the primary combustion air A can be adjusted. The amount of oxygen O mixed with the primary combustion air A is adjusted by detecting the temperature of the grate with a plurality of temperature detectors 17 such as thermocouples embedded in the combustion stoker 9b, and interposing the oxygen supply pipe 15 with the detected value. The oxygen amount adjusting valve 16 is controlled by a temperature controller 18. The operator may manually adjust the amount of oxygen O mixed with the primary combustion air A.

  Thus, in the stoker-type incinerator 1 having the above-described structure, the waste W introduced into the furnace from the waste supply hopper 8 advances sequentially on the dry stoker 9a, the combustion stoker 9b, and the post-combustion stoker 9c. However, the primary combustion is performed by the primary combustion air A and the oxygen-enriched air A ′ supplied to the hoppers 10 under each stoker.

  That is, the waste W introduced into the furnace from the waste supply hopper 8 is continuously supplied onto the dry stalker 9a, from the primary combustion air A and the furnace wall and flame supplied from below the dry stalker 9a. Is heated and dried by the radiant heat, and combustion starts in a part of the waste W. Thereby, the water in the waste W evaporates and unburned gas such as CO is released.

Next, the dried waste W is sent from the dry stalker 9a to the combustion stalker 9b, which is the center of waste combustion, where the flame is raised by the oxygen-enriched air A 'supplied from below the combustion stalker 9b. While burning, the burnout point is just reached at the downstream end of the combustion stoker 9b.
At this time, since the oxygen-enriched air A ′ is supplied to the lower side of the combustion stoker 9b, the incinerated ash D on the combustion stoker 9b rises to a temperature near the melting point at which the incinerated ash D is in a semi-molten state and becomes clinker. Thereby, harmful substances such as dioxins contained in the incineration ash D are decomposed and removed, and volatilization of heavy metals is promoted. Moreover, since the combustion stoker 9b is a water-cooled stoker, the fire grate of the combustion stoker 9b can be protected against an increase in combustion temperature, and burning of the fire grate can be prevented. Furthermore, since the temperature of the grate of the combustion stoker 9b is detected by the temperature detector 17, and the amount of oxygen O mixed with the primary combustion air A is controlled based on the detected temperature, the grate is protected. It can be performed more reliably and better.

  The waste W burned out at the downstream end of the combustion stoker 9b is continuously sent onto the post-combustion stoker 9c, where it is so-called combustion by the primary combustion air A supplied from below the post-combustion stoker 9c. After the incinerated ash D has almost no unburned content, it is dropped and discharged from the ash outlet 7a.

  The incinerated ash D discharged from the ash outlet 7a is divided into coarse ash Da (diameter ≧ 2 to 50 mm of coarse ash Da) and dioxins having a low concentration of dioxins and heavy metals by a particle size sorter 19 such as a vibrating screen. And fine particle ash Db having a high concentration of heavy metals (diameter of fine ash Db <2 to 50 mm).

  The coarse-grained ash Da (diameter of 2 to 50 mm or more) subjected to particle size sorting is subsequently sent to the wind power sorter 20, where the fine ash Db adhering to the coarse-grained ash Da and light unburned matter etc. Are separated and then sent to the magnetic separator 22 and the aluminum separator 23, and the magnetic separator 22 and the aluminum separator 23 sort and collect iron and aluminum, respectively. The coarse ash Da from which valuables such as iron are recovered can be effectively used as it is because the concentration of dioxins and the concentration of heavy metals are low as is clear from Table 1.

On the other hand, the fine ash Db (having a diameter of less than 2 to 50 mm) subjected to the particle size selection by the particle size sorter 19 and the fine ash Db separated by the wind power sorter 20 and collected by the dust collector 21 are disposed in the waste supply hopper 8. It is returned to the inside and re-entered into the furnace.
At this time, the fallen ash that has fallen into the hopper 10 under the stoker and the dust that has settled in the temperature reducing section of the waste heat boiler 2 and the economizer also contain unburned matter and solid dust lump etc., so together with the fine ash Db Returned to the waste supply hopper 8 and re-entered into the furnace. The fine ash Db or the like is pelletized before being put into the waste supply hopper 8 to prevent scattering when the fine ash Db or the like is put into the waste supply hopper 8. Of course, the fine ash Db or the like may be put into the waste supply hopper 8 as it is.

In this way, fine ash Db (including boiler dust and temperature-reducing part dust) is reintroduced into the furnace, so that the ash layer on the stoker 9 is thickened and the stoker 9 is covered with the ash layer. Therefore, the grate of the stoker 9 can be protected.
Further, in order to protect the grate of the stoker 9 more reliably, the temperature of the grate of the combustion stalker 9b is detected by the temperature detector 17, and oxygen-enriched air supplied to the bottom of the combustion stalker 9b based on the detected temperature. The amount of A ′ and the amount of fine ash Db circulated in the furnace are controlled respectively.
That is, the temperature of the grate of the combustion stalker 9b is monitored by the temperature detector 17, and when the grate temperature is equal to or higher than the set temperature (a temperature that can prevent the grate from burning), the oxygen-enriched air A The amount of ′ is reduced to reduce the temperature, and the amount of fine ash Db to be circulated is increased. Conversely, when the grate temperature is low, the amount of oxygen-enriched air A ′ is increased and The amount of oxygen-enriched air A ′ and the amount of fine-grained ash Db are adjusted so as to reduce the amount of fine-grained ash Db. This adjustment may be either automatic control or manual operation by an operator.
Accordingly, even when the waste W having a low ash content and a high calorific value is incinerated, the grate of the stoker 9 is not exposed to heat or excessively heated, and the grate is surely burned out. It can prevent well. As a result, maintenance costs can be reduced by burning out the grate.

The combustion exhaust gas generated in the furnace is recovered by the waste heat boiler 2 and then flows into the exhaust gas treatment device 4 such as a bag filter. After the fly ash D ′ in the combustion exhaust gas is removed, the combustion exhaust gas is cleaned. Gas is released from the chimney into the atmosphere.
Fly ash D ′ collected by the exhaust gas treatment device 4 is sent to a heating and desalting device 5 to decompose dioxins and then sent to a kneading device 6 where a heavy metal stabilizer such as liquid chelate, cement, etc. Is added and kneaded and solidified. Thereby, it can prevent that heavy metals elute from fly ash D '.

  In the above embodiment, the primary combustion air A supplied to the combustion stoker 9b is mixed with oxygen O to form oxygen-enriched air A ', and this oxygen-enriched air A' is used as the primary combustion air A. In the other embodiment, oxygen O is mixed with the primary combustion air A supplied under the dry stoker 9a and the post-combustion stoker 9c, and the dry stoker 9a and The oxygen-enriched air A ′ may be supplied as the primary combustion air A under the post-combustion stoker 9c.

  In the above-described embodiment, the combustion stoker 9b is a water-cooled stalker. However, in other embodiments, the dry stalker 9a and the post-combustion stalker 9c may be a water-cooled stalker.

  Further, in the above embodiment, the temperature detector 17 such as a thermocouple is embedded in the grate of the combustion stoker 9b to monitor the temperature of the grate. However, in other embodiments, the temperature of the grate is monitored. A non-contact thermometer (not shown) may be provided under the combustion stoker 9b to monitor the temperature of the grate.

1 is a schematic system diagram of a waste treatment plant using a stoker-type incinerator according to an embodiment of the present invention. It is a schematic system diagram of the waste disposal plant using the conventional stoker type incinerator and melting furnace.

Explanation of symbols

  1 is a stoker-type incinerator, 7a is an ash outlet, 9 is a stalker, 9a is a dry stoker, 9b is a combustion stoker, 9c is a post-combustion stoker, 17 is a temperature detector, 19 is a particle size sorter, 20 is a wind sorter A is primary combustion air, A 'is oxygen enriched air, D is incinerated ash, D' is fly ash, Da is coarse ash, Db is fine ash, O is oxygen, and W is waste.

Claims (3)

  The primary combustion air is divided and supplied under the stoker divided in the flow direction of the waste, and the waste on the stoker is sequentially dried, burned and burned to form incinerated ash, and the incinerated ash is placed downstream of the stoker. In a stoker-type incinerator that discharges from a certain ash outlet, particle size selection that separates the incinerated ash discharged from the ash outlet into coarse ash and fine ash at a position downstream of the ash outlet. In addition to installing the machine, the selected fine ash is reintroduced into the furnace together with the waste, and among the divided stalkers, at least from the main combustion center to the flaming point located at the burnout point A stoker-type incinerator characterized in that oxygen is mixed with primary combustion air to be supplied to make the primary combustion air oxygen-enriched air, and a stoker to which oxygen-enriched air is supplied is a water-cooled stoker.   A wind power sorter that separates fine ash and unburned matter adhering to the coarse ash selected by the particle size sorter is installed at the downstream side of the particle size sorter, and the separated fine ash and unburned matter are separated. The stoker-type incinerator according to claim 1, wherein the furnace is re-introduced into the furnace.   The temperature of a stoker grate to which oxygen-enriched air is supplied is detected by a temperature detector, and the amount of oxygen mixed in the primary combustion air is controlled based on the detected temperature. A stoker-type incinerator according to claim 1 or claim 2.

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