JPH0755123A - Method and device for incineration of waste - Google Patents

Abstract

PURPOSE:To provide a method for incineration of waste which can incinerates well and stably without any pretreatment such as breaking, even when waste of different shapes and properties are mixed. CONSTITUTION:A hearth is constituted by being divided into a stepping stoker 11 on a waste inlet 2 side, and a moving layer 29 and a fluidized layer 30 on an incineration remains outlet side. Waste 10 may be dried and partly burned on the stoker 11, again burned slowly in the moving layer 29 and further burned, then completely, on the fluidized layer 30. The moving and fluizdized layers 29 and 30 are both formed on a series of fluidizing air jetting floors which incline down toward rearward. At this time, a floor part 141 which forms the moving layer 29 is formed in a steep slope, while a floor part 142 which forms the fluidized layer 30 is formed in a gentle slope.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste incineration method and apparatus for incinerating various industrial wastes including municipal waste and sludge.

[0002]

2. Description of the Related Art A conventional method for incinerating waste of this type is generally a stair stoker in which a movable grate and a fixed grate are combined in a stepwise manner while transferring and stirring waste such as dust. A stoker-type incineration method in which combustion is performed and a fluidized-bed-type incineration method in which waste is combusted while being fluidized by a fluidized bed formed on the bottom of the furnace are well known.

[0003]

In the stoker type incineration method, even if large-sized waste is contained, it can be incinerated as it is without performing pretreatment such as crushing treatment. High-calorie and lightweight paper for municipal waste,
Since it contains a large amount of plastic and the like, the combustion rate on the stoker becomes faster, and the ash layer on the stoker cannot be sufficiently secured. Therefore, troubles such as burnout of the grate are likely to occur, and stable combustion is also difficult. Moreover, since the stoker is generally composed of a dry stoker, a combustion stoker, and a post-combustion stoker, the burning loss of the incineration ash is large and the hearth load factor (about 200 Kg / m ² h) is small, which is also considered. , The hearth is inevitably large, and the entire furnace is larger than necessary.

On the other hand, in the fluidized bed type incineration method, the hearth load is larger than that of the stoker furnace (about 500 Kg / m ² h),
Moreover, the ignition loss is less than 1%, and it is easy to ignite and stop. However, since the combustion ratio greatly changes depending on the shape and properties of the waste supplied to the fluidized bed, it is necessary to perform pretreatment such as crushing treatment in advance, resulting in poor treatment efficiency.
The financial burden such as equipment costs and operating costs required for pretreatment is also large. Moreover, when waste containing high calorie lightweight materials such as those described above is crushed, the proportion of floating combustion increases,
The amount of combustion in the fluidized bed will decrease, making it difficult to maintain the fluidized bed at a predetermined temperature. Moreover, the crushed high-calorie lightweight material explosively burns, causing large pressure fluctuations in the furnace, resulting in CO shortage due to lack of combustion air.
Cause a large number of outbreaks. In this way, the combustion rate ratio in the fluidized bed changes depending on the shape and properties of the waste, and a stable fluidized bed temperature cannot be obtained, making stable combustion difficult. Also,
Since it is necessary to periodically discharge the incombustibles together with the fluidized medium from the central hole of the inverted cone-shaped furnace bottom, continuous operation cannot be performed for a long time, and the incineration efficiency is poor.

The present invention does not cause such a problem and does not require any pretreatment such as crushing treatment even when wastes of various shapes and properties are mixed and is in a stable state. It is an object of the present invention to provide a waste incineration method that can be incinerated favorably and a waste incinerator that can suitably perform the method.

[0006]

The waste incineration method of the present invention which has solved this problem is the first method of communicating with each other in the incinerator.
And the second combustion chambers are arranged in parallel in front and rear, the first combustion chamber is provided with a stepped stoker that extends downward from the waste supply port to the rear, and the second combustion chamber is provided with a rear end portion of the stoker. A series of fluidized air jets consisting of a steep slope that extends downward from the position directly below the rear end and a gentle slope that extends rearward from the rear end of the part to the incineration residue discharge port. A bed is provided, and fluidized air ejected from the gently sloping portion forms a fluidized bed of a granular fluidized medium on the portion, and from the steeply sloping portion, a smaller amount of fluid than the amount necessary to form the fluidized bed is formed. The moving air is ejected to form a moving bed on which the granular fluidized medium gently flows, and the waste supplied from the waste supply port to the first combustion chamber is agitated and dried by a stoker, Partially burned and transferred to the rear, By supplying to the combustion chamber, it is burnt in a moving bed and fluidized bed, and thereafter, in which the incineration residue containing incombustibles was to be discharged from the incineration residue 渣排 outlet. In such a method, the amount of combustion air supplied to the stoker and the feed rate of the waste by the stoker, that is, the forward / backward moving speed of the movable grate, are controlled by maintaining the combustion state of the waste on the stoker in a dry or partial combustion state. So that
It is preferable to control based on the temperature of the first combustion chamber and the like. In particular, it is preferable to control the amount of combustion air in the range of 30% or less of the theoretical combustion air. Further, it is preferable that air is jetted from the rear end of the stoker toward the second combustion chamber so that the waste brought to the rear end of the stoker is dispersed farther away.

In the waste incinerator of the present invention for carrying out this method, first and second combustion chambers communicating with each other are provided in parallel in the front and rear in the incinerator, and the first combustion chamber is provided with the waste. A stair-type stoker is provided which extends downward from the position directly below the supply port to the rear, and the incineration residue discharge port extends downward from the position directly below the rear end of the stoker to the second combustion chamber. Is provided with a fluidized air jet bed, and the fluidized jet bed is provided with a gently inclined portion for jetting a sufficient amount of fluidized air to form a fluidized bed of a granular fluidized medium, and a stoker from the portion. It is proposed that the part on the side is made steeper than the gentle slope and has a steep part that ejects a smaller amount of fluidized air than the amount necessary to form a fluidized bed. is there. In such an apparatus, it is preferable to further provide a wind selection mechanism that ejects air from the rear end of the stoker toward the second combustion chamber. Regarding the inclination angle of the fluidized air jet bed with respect to the horizontal plane, it is preferable that the steeply inclined portion be 30 ° to 70 ° and the gently inclined portion be 10 ° to 25 °.

[0008]

The waste supplied from the waste supply port onto the stoker is agitated, dried and partially burned while being transferred on the stoker.

At this time, the hearth is divided into a stoker and a fluidized bed, and the stoker has the functions of stirring, drying, partial combustion and supplying the waste to the fluidized bed. In addition, the total length is smaller than that in a normal stoker furnace (1/3 or less). Therefore,
Even if a large amount of high-calorie lightweight materials such as plastic and paper are included, only partial combustion (mainly drying and gasification of waste) is performed on the stoker, and a sufficient thickness on the stoker is used. Since the waste layer remains and is maintained, troubles such as heat loss of the grate will not occur.
In addition, while being transported on the stoker, the waste is only partially burned as described above, and is mainly dried and gasified, so that the shape and properties (calorie, water content, etc.) are made uniform. Will be.

Then, the waste material brought to the rear end of the stoker is supplied to the moving bed, further brought to the fluidized bed, and completely burned while passing through both beds.

At this time, since the amount of supplied air is insufficient in the moving bed, even lightly combustible waste is not instantaneously burned by being supplied to the moving bed. Moreover, in the moving bed, since the fluidized air jet bed is composed of a steeply inclined portion having a large inclination angle, a downward flow is formed by the fluidizing medium. Therefore, the lightweight waste is quickly transferred to the fluidized bed by this flow and is well combusted.

By the way, if the waste is sprayed from the rear end of the stoker to the second combustion chamber by the air blown out by the wind-selecting mechanism, the light waste among the waste is far away and the heavy waste is heavy. Will be sprayed closer, and the combustion of the waste will be more appropriate depending on its weight.

That is, the spraying distance of the waste by the jet air is such that iron flakes, wires, stones and other incombustibles or heavy combustibles are mainly supplied to the moving bed without being scattered far from the rear end of the stoker. The residence time in the moving bed and the fluidized bed becomes extremely long. Therefore, a combustible material that is heavy or has a large shape and requires a long time for combustion is completely combusted in combination with the fact that it is subjected to pretreatment such as drying by a stoker. Also, in the moving bed, since the floor is composed of a steeply sloping part with a large tilt angle, it is necessary that at least the amount of air blown out is such that heavy waste flows smoothly and stays in the moving bed. There is no.

On the other hand, regarding the light combustible material which is easy to burn,
It is supplied directly to the fluidized bed and is burned only by the fluidized bed. At this time, the lighter the item, the farther it is scattered,
It is supplied to a region on the rear side of the fluidized bed. That is, the lighter and easier to burn, the shorter the burning time. Therefore, the heat load in the fluidized bed is equalized, and in combination with the treatment rate by the stoker, the combustion rate in the fluidized bed can be maintained constant, and stable combustion is performed at a stable fluidized temperature. . Moreover, since both combustion chambers are in communication, the combustible gas generated by partial combustion on the stoker and the combustion exhaust gas from the fluidized bed are mixed, and complete combustion is achieved by the supply of secondary combustion air. Become. For this reason, the freeboard combustion is effectively performed, and the generation of CO is reduced. In addition, the transfer rate by the stoker is determined by the shape of the waste supplied from the waste supply port,
The combustion in the fluidized bed can be stabilized by adjusting according to the change in the properties.

From these facts, rapid combustion is suppressed and stable combustion is performed even when waste containing a large amount of volatile matter and a high combustion rate is contained. Moreover,
Generation of dioxin can be reduced by complete combustion by supplying secondary combustion air.

Further, among the incombustibles, heavy ones settle at the bottom of the moving bed or fluidized bed, but since the fluidized air jet bed which is the bottom of the bed is inclined from the stoker side to the incineration residue discharge port, Combined with the fact that the front portion of the floor is a steeply inclined portion with a large inclination angle, it smoothly flows down on the fluidized air jetting bed and is discharged satisfactorily to the incineration residue discharge port. Therefore, there is no need to perform periodic cleaning as in a normal fluidized furnace, and continuous operation is possible.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be specifically described below based on the embodiments shown in FIGS.

First, the structure of the waste incinerator of the present invention will be described. In this device, as shown in FIG.
A waste supply port 2 and an incineration residue discharge port 3 are provided on the front and rear walls of the incinerator 1, and the first and second combustion chambers 4, 5 and the secondary combustion chamber 6 and the boiler section combustion chamber that communicate with each other in the furnace 1 are provided. 7 is provided.

A waste input hopper 8 is connected to the waste supply port 2, and a pusher 9 provided on a lower end chute portion 8a of the hopper 8 is advanced and retracted to remove dust, sludge and the like in the hopper 8. The waste 10 can be quantitatively supplied from the supply port 2 into the furnace 1. The supply port 2 is sealed by the stored waste 10 in the hopper 8 (so-called material seal), but in order to ensure the sealing, the upper opening of the hopper 8 can be sealed by the fire door 8b. It has become.

The first combustion chamber 4 is provided in the lower front portion of the furnace 1. In the combustion chamber 4, as shown in FIG. 1, the first combustion chamber 4 is inclined downward from the position directly below the waste supply port 2 toward the rear. A staircase-type stoker 11 is provided which extends.

The stoker 11 is, similarly to the conventionally known one, provided with a fixed grate and a movable grate in a stepwise manner, and the movable grate is moved in the front-back direction by an appropriate driving device (not shown). By reciprocally driving the feed port 2
The waste 10 supplied from the stoker 11 to the front end of the stoker 11 can be moved backward while being stirred. The feed speed of the waste 10 by the stalker 11, that is, the forward and backward moving speed of the movable grate can be adjusted by controlling the driving device. Further, a wind box 12 is provided below the stoker 11, and combustion air is supplied from a combustion air supply pipe 13 connected to the wind box 12. The amount of combustion air supplied to the stalker 11 can be adjusted by controlling an air volume adjustment damper 13a provided in the combustion air supply pipe 13. Further, a riddle ash hopper 15 is provided under the stoker 11 so as to collect unburned ash and the like that fall from a gap between the grate and the like.

Further, a temperature detector 19 for detecting the temperature of the first combustion chamber 4 is installed on the front wall of the first combustion chamber 4, and based on the temperature detected by the temperature detector 19, the air volume adjusting damper 13a and It is designed to control the drive of the grate. That is, the amount of combustion air supplied to the stoker 11 and the longitudinal velocity of the grate, that is, the feed speed of the waste 10 are adjusted so that the temperature of the first combustion chamber 4 is maintained at the partial combustion temperature, that is, the waste 10 is discharged. The combustion state by the stoker 11 is suppressed to partial combustion without reaching the total combustion,
It is controlled so that it can be maintained. In this case, the amount of combustion air supplied to the stoker 11 is controlled within the range of 30% or less of the theoretical amount of combustion air. Therefore, the pusher 9 allows the waste supply port 2 to pass through the stoker 1
The waste 10 supplied to the front end portion of No. 1 is dried and partially burned while being stirred while being transferred on the stoker 11 to the rear end portion. By the way, since the stoker 11 does not aim at complete combustion like a normal stoker, but does aim at partial burning, its total length is inevitably shorter than a normal stoker. Specifically, the total length of the stoker 11 can be set to 1/3 or less of the stoker in the step-type stoker furnace described at the beginning.

Further, the following wind selecting mechanism 20 is attached to the rear end of the stalker 11, that is, the fixed grate 11a at the lowermost stage.

That is, as shown in FIGS. 1 and 2, the wind selecting mechanism 20 is provided with a plurality of air ejection holes 21 ... (Only one is shown) arranged in the left-right direction on the rear end wall of the lowermost grate 11a. In addition to being installed, the air ejection hole 2 is provided below the lowermost grate 11a.
1 is attached to an air header 22, and an air supply pipe 23 is connected to the air header 22 so that the air ejection holes 21 ...
Is configured to eject air from the second combustion chamber 5 to the second combustion chamber 5. It should be noted that the ejection amount from the ejection holes 21 ... Can be adjusted by an air volume adjustment damper 23a provided in the air supply pipe 23. The air supply pipe 23 is branched and connected to the combustion air supply pipe 13 and uses a part of the combustion air as jet air.

The second combustion chamber 5 is provided in the lower rear portion of the furnace 1. In this combustion chamber 5, as shown in FIGS. 1 and 2, from the position directly below the rear end of the stoker 11 to the rear side. And a series of fluidized air consisting of a steeply inclined portion 14 ₁ extending downwardly and a gentle inclination portion 14 ₂ extending rearwardly downward from the rear end of the portion 14 ₁ and reaching the incineration residue discharge port 3. A spouting bed 14 is provided. That is, the fluidized air jet floor 14 is the refractory wall 2 erected under the rear end of the stoker 11.
4 and a refractory wall 25 which is a front wall of the incineration residue discharge port 3.

Steep slope 14₁Is water as shown in FIG.
The slant angle α with respect to the plane₂Tilt angle
It is made larger than β and has a floorboard 16 with a fireproof wall structure.₁Up
A plurality of nozzles 17₁... in the horizontal direction, which is the width direction of the furnace
The floorboards 16 are planted in parallel at regular intervals.₁Under
Wind box 18₁The fluidized air supplied to the nozzle 17₁… Or
It is configured to eject from. Wind box 18₁Flow into
Branch pipe 26 of motive air supply pipe 26₁Is connected,
This branch pipe 26₁Air volume adjustment damper 27 ₁By
Nozzle 17₁So that the amount of air blown from
ing.

Gently sloping portion 14₂As shown in FIG.
Floorboard 16 of fire wall structure₂In the upper part of the furnace,
A plurality of nozzles 17 arranged in parallel at regular intervals₂…(Less than
"Row nozzle group 17 '₂") Closely in the front-back direction
Floors 16 ₂Supplied to the wind box below
Fluidized air is passed through the row nozzle group 17 '₂I'm gonna gush from
It is configured as In this example, the wind box
Le group 17 '₂The number of wind boxes corresponding to 18₂Split into ...
With these wind boxes 18₂Fluidized air supply pipes for each
26 branch pipes 26₂... and connect each branch pipe 26₂Set up
Displacement adjustment damper 27₂Each row nozzle group 17
´₂Independently adjust the amount of fluidized air ejected from each
You can do it. The front row nozzle group
17 '₂Each nozzle 17 that composes₂Is a steep slope 4₁
Each nozzle 17₁Is closely related to.

Each nozzle 17 is, as shown in FIGS.
The upper and lower surfaces are inclined surfaces parallel inclined surfaces (the steep slope portion 14 ₁ of the nozzle 17 _first angle α to the floor plate 16, the gentle decline portion 1
4, the _second nozzle 17 ₂ is an inclined surface of the angle beta) and cross-sectional mushroom shape which has been configured in the hollow body, the lower end opening 17
b is fixedly held by a mounting member 28 which is fixed through the floor plate 16. As shown in FIG. 4 and FIG. 5, a plurality of ejection holes 17a, which are arranged in parallel in the front-rear direction at regular intervals, are formed in the left and right side walls of the bulging portion 17c, which is the upper portion of the nozzle 17, in an inclined state that is inclined rearward. The fluidized air is ejected backward and downward from each ejection hole 17a.

[0029] In Thus, the amount of air jetted from the gentle slope portion 14 _2, by adjusting the dampers 27 ₂ ..., partial 14 ₂
It is set to an amount sufficient to form a fluidized bed 30 with a granular fluidized medium such as silica sand or alumina (sand is used in this embodiment). Further, in this embodiment, the amount of jetted air is adjusted so as to increase toward the rear side of the row nozzle groups 17 ′ ₂ ...
A circulation flow 30a as shown in FIG. 2 is formed therein. That is, since the height of the sand layer is higher toward the rear on the gently inclined portion 14 ₂ which is inclined downward toward the rear, this is combined with the fact that air is ejected rearward from each nozzle 17 _2. Thus, the jetted air is raised toward the lower sand layer height with less pressure loss, that is, diagonally forward, and as a result, the above-described circulation flow 30a is formed. The vertical distance between the rear end of the stalker 11 and the fluidized air jet bed 14 is set so that the upper surface of the stationary layer portion of the fluidized bed 30 is not higher than that of the stalker 11, but in general, the stationary layer portion 1.5 of height
It is preferably about 2.5 times.

Further, the amount of air ejected from the steeply inclined portion 14 ₁ is set to be smaller than the amount necessary for forming a fluidized bed by adjusting the damper 27 ₁ . Therefore, on the steeply inclined portion 14 ₁ , a fluidized bed as on the gently inclined portion 14 ₂ is not formed,
As shown in FIG. 3, I steep coupled with steep portion 14 _1, the granular bed material gentle downward flow by 2
A moving layer 29, which is a sand layer in which 9a is generated, is formed. The constituent sand of the moving bed 29 is kept at the same temperature as the sand temperature in the fluidized bed 30.

By the way, the inclination angle α of the steeply inclined portion 14 ₁
The heavy waste 10 supplied to the moving bed 30 in which a strong flow such as the above-described circulation flow 30a is not formed is the portion 1
4 ₁ As can be caused to smoothly flow down without staying on the, preferably it is kept as 30 ° to 70 ° approximately, in this embodiment is set to approximately 40 °. In addition, the inclination angle β of the gently inclined portion 14 ₂ is combined with the action of the circulation flow 30a, and the heavy waste 10 such as an incombustible material smoothly flows down on the portion 14 ₂ to the incineration residue discharge port 3. It is preferable to set it to about 10 ° to 25 ° so that it can be set, and in this embodiment, it is set to about 20 °. Further, the inclination angle γ (see FIG. 5) of the ejection hole 17a in the nozzle 17 is
In general, it is preferable to set the moving bed 29, the fluidized bed 30, and the circulating flow 30a at about 30 ° to 60 ° so that the moving bed 29, the circulating flow 30a, and the like can be formed and maintained well. Of course, the axial length of the ejection hole 17a is set so that the fluid medium does not enter the nozzle 17 through the ejection hole 17a in cooperation with the inclination angle γ.

As shown in FIG. 1, the secondary combustion chamber 6 is formed above the communicating portion of the first and second combustion chambers 4 and 5. On the peripheral wall of the secondary combustion chamber 6, the secondary combustion air nozzle 31 ...
Is provided, and the combustion air supply pipe 1 is provided in the nozzle 31.
A secondary combustion air supply pipe 32 branched from 3 is connected, and a part of the combustion air is ejected to the secondary combustion chamber 6 as secondary combustion air. Due to the supply of the secondary combustion air, the unburned components in the exhaust gas rising from the combustion chambers 4 and 5 are secondarily burned. In addition, the ejection amount of the secondary combustion air can be adjusted by an air volume adjusting damper 32a provided in the supply pipe 32.

As shown in FIG. 1, the boiler combustion chamber 7 is connected to the upper portion of the secondary combustion chamber 6, and the exhaust gas from the secondary combustion chamber 6 is subjected to heat recovery by the boiler 7a, and then the furnace 1 It is designed to be discharged outside. Further, the exhaust gas that has passed through the boiler 7a is discharged from the chimney 35 through the appropriate dust collector 33 and the inducing fan 34.

Furthermore, at the lower end of the incineration residue discharge port 3,
As shown in FIG. 1, an L-shaped incineration residue reservoir 36 is continuously provided to store incineration residues (including incombustible substances) discharged from the discharge port 3. The incineration residue stored in the incineration residue reservoir 36 material-seals the discharge port 3 in the same manner as the stored material 10 in the hopper 8. A pusher 37 is arranged in the incineration residue reservoir 36 so that the incineration residue is discharged onto the vibrating screen 38. The vibrating screen 38 has a water cooling structure as required. Further, the fluidized medium contained in the residue discharged from the incineration residue reservoir 36 is separated from the incombustibles and the like by the vibrating screen 38, and then the second conveying medium 39
The fluidized medium supply port 5a provided on the ceiling wall of the combustion chamber 5 returns the fluidized medium to the fluidized bed 30. Further, an unburned ash blowing nozzle 40 is provided on the rear wall of the second combustion chamber 5, and the unburned ash blowing pipe 41 branched from the fluidizing air supply pipe 26 and guided to the nozzle 40 is drooped from the redling ash hopper 15. The unburnt ash recovery pipe 42 is connected so that the unburnt ash recovered in the hopper 15 can be blown into the second combustion chamber 5 by utilizing a part of the combustion air. The blow pipe 41 is provided with an air volume adjusting damper 41a for adjusting the blow air amount.

The left and right widths of the waste supply port 2, the incineration residue discharge port 3, the hopper 8, the pushers 9, 37, the stoker 11, the fluidized air jet bed 14, and the incineration residue reservoir 36 are the width of the furnace, that is, the incinerator 1. The width is approximately the same as the left-right width (about 4 m).

The method of the present invention is carried out as follows using the incinerator configured as above.

That is, the waste 10 supplied from the waste supply port 2 to the first combustion chamber 4 is agitated, dried and partially burned while being transferred backward on the stoker 11.

At this time, the total length of the stoker 11 is shorter than that of a normal stoker in the stoker furnace (1/3 or less).
Therefore, the waste layer having a sufficient thickness remains and is maintained on the stoker 11, and only the light and easily combustible waste 10 existing on the upper portion of the stoker 11 is burned, and on the stoker 11, The waste 10 will be gently burned while being stirred and transferred. Therefore, even when the waste 10 contains a lot of high calorie lightweight materials, the generation of suspended solids is extremely small, smooth and stable combustion is performed, and troubles such as heat loss of the grate do not occur. Further, even if wastes of different sizes are mixed, the shape of the stoker 11 can be made uniform by the combustion. Further, the wet waste is transferred over the stalker 11 over time, so that it is sufficiently dried in the meantime. As a result, even when the waste 10 is a mixture of substances having different shapes and properties, the shapes and properties are substantially uniformed in combination with the fact that they are mixed and stirred while passing through the stoker 11. Moving bed 29 or fluidized bed 3
Will be supplied to zero. Further, by controlling the forward / backward movement speed of the movable grate, the inside of the first combustion chamber 4 is maintained at a temperature at which the combustion state on the stoker 11 is suppressed to dry and partial combustion, so that the waste 10 is substantially constant. Thus, the combustion and temperature in the fluidized bed 30 are stabilized.

The waste 10 brought to the rear end of the stoker 11 is the air ejection hole 2 of the lowermost grate 11a.
The air ejected from Nos. 1 ... Is scattered to the second combustion chamber 5, is supplied to the moving bed 29 or the fluidized bed 30, and is burned in these beds 29, 30.

At this time, the spray distance of the waste 10 by the jetted air becomes larger as the weight becomes lighter and becomes smaller as the weight becomes heavier.
That is, light materials such as plastic and paper are scattered far away and supplied to the fluidized bed 30, and inflammable materials such as iron pieces, wires, and stones and heavy combustible materials are far away from the rear end of the stoker 11. It is mainly supplied to the moving layer 29 without being scattered. Such spraying ability can be arbitrarily controlled by changing the ejection conditions from the ejection holes 21. For example, under the ejection conditions of an air pressure of 50 mmH ₂ O and an air ejection velocity of 40 m / s, the stoker 11 can be controlled. It can be sprayed up to a maximum of 3 m from the rear end, and the bulk specific gravity of waste in the spraying area is 0.5 to 0.05 t.
A / m ^3.

Therefore, the lighter and easier to burn, the lighter the one, the rear side of the fluidized bed 30 (the incinerator residue discharge port 3 side).
And the combustion time by the fluidized bed 30 is shortened.
On the other hand, those that take a long time to burn because they are heavy or have a large shape are slowly burned in the moving bed 29 in which a gentle downward flow 29a is formed, and further the fluidized bed 3
It will be burned in 0, and will burn completely in both layers 29 and 30 over a sufficient time.
That is, as it takes a longer time to completely burn, the heavy waste 10 is supplied to the front side of the moving bed 29 so that the residence time in both beds 29, 30 becomes longer. It can be burned reliably regardless of its weight and shape. In this way, since the combustion time is given according to the type of waste 10,
Combined with the pretreatment such as drying by the stoker 11 in advance, the waste 10 of any shape and property can be burned well.

In addition, since the amount of air supplied to the moving bed 29 is insufficient and a gentle downward flow 29a is formed, even when a large amount of waste 10 is supplied to the moving bed 29, the moment Combustion occurs in both layers 29 and 30 in a sufficient and stable state without any specific combustion. Furthermore, since the steeply inclined portion 14 ₁ has a large inclination angle α, the heavy waste material containing the incombustible material forms only a gentle downward flow 29a.
In 9 as well, the fluidized bed 30 can be smoothly flowed down to the incineration residue discharge port 3 without staying.

Therefore, the waste 10 is burned and burned in an efficient and stable state in a low oxygen atmosphere in combination with the fact that the waste 10 is circulated and fluidized by the circulation flow 30a in the fluidized bed 30. Become. Further, since the combustion chambers 4 and 5 are in communication with each other, the combustible gas generated by the partial combustion on the stoker 11 and the combustion exhaust gas from the fluidized bed 30 are mixed, and the secondary combustion from the nozzles 31 ... It is burned by the supply of air, and as a result, the freeboard combustion is effectively performed and the generation of CO is reduced.

The unburned ash dropped from the stoker 11 is blown from the nozzle 40 to the rear side region of the second combustion chamber 5 by utilizing a part of the fluidized air, and is completely combusted in the fluidized bed 30. become. Therefore, the amount of unburned ash generated can be reduced, and the incineration efficiency of waste can be greatly improved.

Further, among the incombustibles, heavy ones settle on the floor plate 16. However, since the floor plate 16 has a large inclination angle α of the front end portion 16 ₁ , such incombustibles can be generated by the floor plate 16a. It flows down and flows smoothly over the top, and is surely dropped and discharged to the incineration residue discharge port 3. 4 and 5
, The nozzles 17 are closely connected in the front-back direction, which is the downward direction, and a series of downward passages 14a are formed between the nozzle groups 17 that are arranged in a row. There is no hindrance to the presence of. Therefore, unlike in a normal fluidized bed furnace, incombustibles do not stay and accumulate at the bottom of the fluidized bed, and there is no need to stop operation due to cleaning work or the like. As a result, efficient incineration processing can be performed by continuous operation, and eventually effective heat utilization by the waste heat recovery means such as the boiler 7a can be realized.

By the way, since the circulating flow 30a as shown in FIG. 2 is formed in the fluidized bed 30, and the amount of fluidized air jetted is increased toward the rear side region of the fluidized bed 30, the fluidized medium is increased. Also, there is almost no risk that unburned matter will be discharged from the incineration residue discharge port 3. Therefore, there is no inconvenience due to the opening of the incineration residue discharge port 3 under the fluidized bed 30. Of course, only a part of the fluidized medium is the incineration residue discharge port 3
Although they may be discharged from the vibrating screen 38, they are discharged together with the incombustibles to the vibrating screen 38.
In addition to being separated from the incombustibles by 8, the fluid is returned to the fluidized bed 30 from the fluidized medium supply port 5a, and in such a case, no inconvenience occurs.

On the other hand, the exhaust gas generated in the first and second combustion chambers 4, 5 reaches the secondary combustion chamber 6 and the boiler combustion chamber 7, where the unburned components and unburned gas contained in the exhaust gas are It is completely burned. At this time, the surplus of the combustion air supplied from the combustion air supply pipe 13 to the stoker 11 acts as secondary combustion air for secondary combustion of the exhaust gas from the fluidized bed 30, and the secondary combustion air nozzle 31 ... Combined with the air supply from the, the effective secondary combustion function is demonstrated. Therefore, in the furnace 1, stable combustion due to a low excess air ratio can be obtained, and CO and further dioxins can be effectively suppressed. The exhaust gas that has reached the combustion chamber 7 of the boiler is cooled by heat recovery by the boiler 7a, the dust is removed by the dust collector 33, and then discharged from the chimney 35.

The present invention is not limited to the above-mentioned embodiments, but can be appropriately improved and changed without departing from the basic principle of the present invention. For example, the composition ratio of the hearth, that is, the dimensional ratio in the front-rear direction of the hearth part composed of the stoker 11 and the hearth part composed of the moving bed 29 and the fluidized bed 30, and the front and rear parts of both bed parts 14 ₁ and 14 ₂ . The dimensional ratio of the directional length can be appropriately set according to incineration conditions such as the size of the furnace 1. Further, the fluidized air jet bed 14 may be of any structure as long as it can smoothly discharge the incombustibles down the incineration residue discharge port 3. Of course, the waste heat recovery means attached to the furnace 1 is not limited to the boiler 7a, and may be arbitrary.

[0049]

As can be easily understood from the above description, according to the waste incineration method of the present invention, wastes of various types and various shapes and properties can be burned satisfactorily and stably. You can Moreover, without making the furnace too large,
A large amount of waste can be incinerated efficiently and economically. Moreover, according to the waste incinerator of the present invention, such a method can be suitably implemented.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of a waste incinerator according to the present invention.

FIG. 2 is a detailed view showing an enlarged main part of FIG.

FIG. 3 is an explanatory view showing an enlarged main part of FIG.

FIG. 4 is a vertical sectional front view taken along line IV-IV in FIG.

5 is a cross-sectional plan view taken along the line VV of FIG.

FIG. 6 is a perspective view of a nozzle.

[Explanation of symbols] 1 ... incinerator, 2 ... waste supply port, 3 ... incineration residue discharge port,
4 ... 1st combustion chamber, 5 ... 2nd combustion chamber, 10 ... Waste, 11
... Stoker, 14 ... Fluidized air jet bed, 14 ₁ ... Steep slope part, 14 ₂ ... Slow slope part, 20 ... Wind selection mechanism, 29 ... Moving bed, 29a ... Downward flow of granular fluid medium, 30 ... Fluidized bed, 30a ... Circulation flow, α, β ... Inclination angle of fluidized air jet bed with respect to horizontal plane.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eisho Hidaka 1-32 Dojimahama, Kita-ku, Osaka City, Osaka Prefecture Takuma Co., Ltd.

Claims (8)

[Claims] 1. A first and a second communicating with each other in an incinerator.
Combustion chambers are provided side by side in parallel, a first-stage combustion chamber is provided with a stepped stoker that extends downward from the waste supply port in a downward slope, and a second combustion chamber is provided with a position directly below the rear end of the stoker. A series of fluidized air ejection beds consisting of a steeply inclined portion extending downward from the rear to a rearward slope and a gentle inclined portion extending rearward from the rear end of the portion to the incineration residue discharge port are provided. In addition, fluidized air ejected from the gently sloping portion forms a fluidized bed of granular fluidized medium on the portion, and a smaller amount of fluidized air than the amount required to form the fluidized bed is provided from the steeply inclined portion. A moving bed in which the granular fluidized medium gently flows is formed on the part by jetting, and the waste supplied from the waste supply port to the first combustion chamber is agitated, dried, and partially burned by a stoker. While being transferred to the rear, the second combustion chamber So supplied, it is combusted in the moving bed and fluidized bed, after which the waste incineration process being characterized in that so as to discharge the incineration residue containing incombustible from incineration residue 渣排 outlet. 2. The amount of combustion air supplied to the stoker is controlled so that the combustion state of the waste on the stoker can be suppressed and maintained by drying and partial combustion. Waste incineration method. 3. The combustion air amount is 30% of the theoretical combustion air amount.
The waste incineration method according to claim 2, wherein the method is controlled within the following range. 4. The moving speed of the movable grate in the stoker is controlled so that the combustion state of the waste on the stoker can be suppressed and maintained by drying and partial combustion. The waste incineration method according to claim 1, claim 2 or claim 3. 5. The waste is brought to the rear end of the stoker by spraying air from the lowermost part of the stoker toward the second combustion chamber, so that the lighter ones are scattered farther. The waste incineration method according to claim 1, claim 2, claim 3, or claim 4. 6. A first and a second communicating with each other in the incinerator.
Combustion chambers are provided side by side in parallel, and a stepped stoker extending downwardly from a position directly below the waste supply port is provided in the first combustion chamber, and a rear end portion of the stoker is provided in the second combustion chamber. A bed of fluidized air that extends downward from the position immediately below to the rear and reaches the incineration residue discharge port is provided, and this fluidized jet bed has an amount sufficient to form a fluidized bed of granular fluidized medium. A gently sloping portion that jets fluidized air and a steep portion that is a portion closer to the stoker than the portion and that is steeper than the gently sloping portion and that jets a smaller amount of fluidized air than the amount necessary to form a fluidized bed. A waste incinerator characterized by comprising an inclined portion. 7. The inclination angle of the fluidized air jet bed with respect to the horizontal plane is 30 ° to 70 ° for the steeply inclined portion,
The waste incinerator according to claim 6, wherein the gently sloping portion has an angle of 10 ° to 25 °. 8. The waste incinerator according to claim 6 or 7, further comprising a wind selecting mechanism for ejecting air from the rear end of the stoker toward the second combustion chamber.