JPH0573965B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an incinerator or a combustible material that has a fluidized bed for burning and disposing of municipal waste, industrial waste, coal, and other combustible materials with a high calorific value. This relates to an air diffuser used in devices such as boilers that use a fluidized bed to burn and recover thermal energy at the same time.

[Conventional technology]

Conventional fluidized bed devices include fluidized bed boilers or heat recovery devices (Japanese Patent Application No. 61-8880, Japanese Patent Application No. 16726, No. 61-1982, Japanese Patent Application No. 61-1672), which some of the present inventors have already applied for.
52559), a heat transfer section is used to introduce a fluidizing gas into the fluidized bed to flow the fluidized medium. The diffuser for supplying a fluidizing gas such as air to this fluidized bed was simply a device for feeding the fluidizing gas into the fluidized bed.

[Problem that the invention seeks to solve]

However, these heat recovery diffusers for fluidized bed boilers or heat recovery devices devised by the present inventors, for example, when applied to a diffuser pipe, reduce the amount of heat transferred from the heat recovery section in the fluidized bed. When reducing the amount of fluidizing gas or stopping the supply for the purpose of this, the diffuser pipe is overheated by the surrounding sand temperature, which can reach a maximum of 700 to 950 degrees Celsius, causing deformation and corrosion of the diffuser pipe, resulting in concerns about the short life of the diffuser pipe. It was hot.

In addition, when two or more fluidized beds are formed in the same equipment, if the amount of fluidized gas blown into one fluidized bed is extremely reduced, the fluidized gas may be affected by the flow of the other fluidized bed, causing the fluidized gas to flow inside the diffuser tube. There was a risk that the air could enter and clog the air diffuser pipes. For this reason, the diffuser needs to have a special structure that takes countermeasures against the infiltrating fluid medium, making it extremely complicated and expensive.

Moreover, when adjusting the amount of fluidized gas supplied from this diffuser tube to the fluidized bed for the purpose of arbitrarily changing the amount of heat transfer, especially in a region where the amount of fluidized gas is low, the diffuser tube The amount of gas supplied to the area becomes significantly smaller. Therefore, in the normal flow adjustment based on the pressure drop of the passing gas, it is difficult to control a minute flow rate due to its characteristics, and it is difficult to set the flowing gas amount to an arbitrary value.

Furthermore, when applied to a fluidized bed that involves combustion, the fluidized air is also combustion air, so if the amount of fluidized air supplied to the fluidized bed is varied to obtain the required fluidization state, the entire fluidized bed will be affected accordingly. This has been a problem because the amount of combustion air supplied to the combustion chamber fluctuates, causing the excess air ratio to fluctuate and making it impossible to maintain the optimum amount for combustion.

The present invention solves these problems and can increase or decrease the amount of gas supplied to the aeration device that passes through the aeration section when blowing fluidized gas into the fluidized bed. To facilitate maintenance by cooling the diffuser and accurately preventing overheating by allowing a certain amount of gas to flow into the diffuser in any operating state, whether gas is supplied or not. The object of the present invention is to provide an air diffuser in a fluidized bed apparatus that enables the following.

[Means for solving problems]

As a means for solving the above-mentioned problems, the present invention provides a fluidized bed apparatus in which a fluidized bed is formed by fluidizing a fluidized medium using a fluidizing gas supplied upward from the bottom. A fluidizing gas blowing diffuser for supplying gas has a structure that allows the fluidized gas to pass within the fluidized bed, and a fluidizing gas supply amount adjustment mechanism to the fluidizing gas diffuser and a fluidizing gas passing amount adjusting mechanism. This is an aeration device in a fluidized bed apparatus characterized by being provided with.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which an embodiment of the present invention is applied to a fluidized bed boiler that also performs combustible combustion and heat recovery will be described with reference to the drawings.

In the examples shown in FIGS. 1 and 2, a distribution plate 22 for fluidizing gas 23 such as air is provided at the inner bottom of the furnace 21, and the distribution plate 22 has both side edges lower than the center, and the center line of the furnace 21. It is formed on an almost symmetrical chevron-shaped cross section (roof-like). The fluidizing gas 23 sent from the forced air blower 27 passes through air chambers 24, 25, and 26 and is ejected upward from the dispersion plate 22. The mass velocity of the fluidizing gas 23 is set to be sufficient to form a fluidized bed of the fluidized medium in the furnace 21, but the mass velocity of the fluidizing gas 23 jetting out from the central air chamber 25 is smaller than the former. selected.

Immediately above the air chambers 24 and 26 on both side edges, a plate-shaped reflecting wall 28 is provided as a reflecting wall that blocks the upward flow path of the fluidizing gas 23 and causes the fluidizing gas 23 to reflect and turn toward the center of the furnace 21. Partition wall 28 ₁
A partition wall 28 ₁ with this reflective wall 28 is provided.
A boiler chamber 29 is formed between the furnace wall and the furnace wall, and a portion of the fluid medium flows over the reflecting wall and flows into the boiler chamber 29 during operation.
Further, at a level higher than the bottom of the furnace in the lower part of the boiler room 29, there is provided an aeration device 32 made of, for example, a dispersion pipe, which blows out fluidizing gas 31 from a blower 30. An opening 33 is provided near the air diffuser 32, and the fluidized medium that has entered the boiler room 29 settles while forming a moving bed or a fluidized bed, either continuously or intermittently depending on the operating state.

Furthermore, a heat transfer tube 35 through which a heat receiving fluid 34 is passed is arranged inside the boiler room 29 or on its wall,
It is designed to exchange heat with a fluidized medium.

As shown in FIG. 2, an upstream flow rate control valve V ₁ and a downstream flow rate control valve V ₂ were provided in the pipe for the fluidizing gas 31 connected to the aeration device 32, and the pipe opened into the furnace wall. It is connected to the secondary air supply port 36. The relationship between the flow rate control valves V ₁ and V ₂ and the flow rate is normally as shown in Fig. 3, but if the opening degree of the flow rate control valve V _{1 on the upstream side of the diffuser pipe is constant, the relationship between the flow rate control valves V 1} and V 2 and the flow rate is as shown in Fig. 4. The supply flow rate can be obtained, and the controllability is excellent especially when the flow rate is small. In this case, the heat transfer coefficient and the amount of flowing air are as shown in FIG. 5, which is preferable in terms of controlling the amount of heat recovery.

In this case, the fluidizing gas blowing diffuser 32
is an aeration pipe having a plurality of gas blowing nozzles 32 ₁ , and the fluidizing gas 31 that has passed through the aeration pipe is
An opening 33 for mixing gas generated from the fluidized bed is provided at a position within the fluidized bed, and a detection gas 3 for detecting the amount of fluidized gas supplied to the aeration section is provided.
7, and is constructed in association with the upstream flow rate control valve _V1 as a fluidizing gas supply amount adjusting mechanism capable of controlling the gas amount to a set value above a certain value. Further, the downstream flow rate control valve V ₂ is configured to control the opening and closing operation of the valve in conjunction with a detector 38 that detects the amount of flowing gas that is provided in the piping so as to function as a mechanism for adjusting the amount of flowing gas passing through the aeration section. It is set as.

Note that when the diffuser 32 of the diffuser section is installed in the fluidized bed of the fluidized bed heat recovery device, the amount of recovered heat can be adjusted by controlling the amount adjustment mechanism of the fluidized gas passing through the diffuser section. It is possible.

For example, a detector (not shown) that detects the amount of recovered heat
The gas diffuser fluidizing gas passage amount adjusting mechanism can be controlled so as to keep the amount of recovered heat constant or to correspond to the detected value of the detector.

In addition, when the aeration section is installed in the fluidized bed of a fluidized bed incinerator, a detector (not shown) for detecting the oxygen concentration in the combustion exhaust gas of the incinerator, and a detector (not shown) for detecting the oxygen concentration in the combustion exhaust gas of the incinerator It is effective to adjust the set value of the fluidizing gas supply amount adjustment mechanism control so that the oxygen concentration is constant according to the detected value of the detector, and the fluidization gas passing amount adjustment mechanism may be adjusted as necessary. It is also possible to control or use them together.

In the example shown in FIG. 6, the diffuser unit 32 is composed of a group of diffuser tubes having an outgoing path 31 ₁ and a returning path 31 ₂ communicating as gas passages, that is, a diffuser tube with a double inner and outer pipe structure and an insertion tube thereof. is an insertion tube group having an outgoing path and a return path, which are connected to the outgoing path 31 ₁ and the incoming path 31 ₂ at the tip, and the aeration section is connected to the outgoing path and the incoming path at the tip of each insertion tube, and the outgoing path 31 ₁ , the incoming path 31 ₂ or the Both have fluidizing gas blowing nozzles 32 into the fluidized bed.
₁ , the outgoing path 31 ₁ is connected to the regulating valve V ₁ of the fluidizing gas supply amount regulating mechanism, and the returning path 31 ₂ is connected to the regulating valve V ₂ of the fluidizing gas passing amount regulating mechanism. Then, air is supplied to the inner pipe of the diffuser pipe and is discharged through between the outer pipe and the inner pipe. The insertion part is slightly lowered and the tip is inclined higher to facilitate the discharge of the infiltrating fluid medium. The blowing nozzle is preferably located at the bottom of the pipe on the outward or return route to prevent the fluid medium from entering.

As shown in the example in Fig. 7, the diffuser pipe is divided into two parts by a tube plate ₃₁₃ and divided into an outgoing path ₃₁₁ and a returning path ₃₁₂ , and the outgoing path ₃₁₁ is connected to the fluidizing gas supply amount adjustment mechanism as in the previous example. , and the return path 31 ₂ may be connected to a fluidizing gas passage amount adjusting mechanism.

Furthermore, in the example shown in FIG. 8, the aeration device 32 of the aeration section is composed of a group of aeration tubes penetrating the fluidized bed,
A nozzle 32 ₁ for blowing fluidizing gas into the fluidized bed is provided at the bottom of each diffuser pipe, one end of the pipe is connected to the control valve V 1 of the fluidizing gas supply amount control mechanism, and the other end is connected to the control valve V ₁ of the fluidizing gas supply amount control mechanism. Control valve V ₂ of fluidizing gas passage amount control mechanism
It is connected to.

That is, the upstream flow rate control valve V ₁ of the diffuser pipe is controlled so that the combustion state is appropriate based on the value of the exhaust gas oxygen concentration detector 52 via the indication adjustment alarm flowmeter 53, and the flow rate control valve V 1 on the downstream side of the diffuser pipe is controlled to be appropriate. ₂ is controlled from the values of the temperature detector 54 of the fluidized bed and the integration indicator 55 of the boiler via an indicator adjustment flowmeter 56 so that the amount of heat recovered in the heat transfer section becomes a required value. From this, even when using a heterogeneous fuel such as municipal waste, or when changing the amount of fuel used due to variations in the amount of evaporation used, the heat transfer coefficient can be changed significantly as shown in Figure 5, and the fluidized bed can be used. It is possible to obtain heat recovery amount control with quick response while performing temperature management and combustion management.

When applied to the aeration section for blowing fluidizing gas into the fluidized medium of the heat recovery section, for example, the fluidized bed in which the fluidized medium is made to flow by the fluidizing gas containing oxygen, which is blown upward from the bottom, is connected to a partition wall. The combustion section is divided into a heat recovery section whose upper and lower portions are communicated with each other and a combustion section which supplies combustible materials, and the flow rate of the fluidizing gas blown per unit area of the combustion section at least in the vicinity of the partition wall is controlled by the heat recovery section. is larger than the fluidizing gas blowing air volume per unit area of , the fluidizing medium of the combustion section is caused to flow into the heat recovery section over the partition wall, and the fluidizing medium of the heat recovery section is flown from the lower part of the partition wall. It is effectively used in a fluidized bed heat recovery device where heat is returned to the combustion section.

In the figure, 57 is a raw material input port provided at the upper part of the furnace 21, and 59 is an air/water drum provided near the exhaust gas outlet 58, which forms a circulation path with the heat transfer tube 35 in the boiler chamber 29. Further, numeral 39 indicates an incombustible material discharge port connected to both side edges of the dispersion plate 22 at the bottom of the furnace 21;
0 is a screw conveyor having a screw 41 disposed in a reverse screw direction, and 42 is a motor.

However, to explain using the example in Fig. 1, the raw material input port 5
The combustible material F introduced into the furnace 21 from 7 is combusted and generates heat while being fluidized together with the fluidizing medium by the fluidizing gas 23. At this time, the fluidized medium near the upper center of the air chamber 25 does not move violently up and down, and forms a moving layer in a weakly fluidized state. The width of this moving layer is
The upper part is narrow, but the bottom part is slightly wider due to the effect of the slope of the dispersion plate 22, and part of the bottom part reaches above the air chambers 24 and 26 on both sides, so that a large mass velocity can be achieved. It is blown up by the injection of fluidizing gas 23. Then, part of the fluid medium at the bottom is removed, so the layer directly above the air chamber 25 descends under its own weight. Above this layer, the fluidized medium from the fluidized bed is replenished and deposited as will be described later, and by repeating this process, the fluidized medium above the air chamber 25 forms a moving bed that gradually descends.

The fluidized medium that has moved onto the air chambers 24 and 26 is blown upward, but when it hits the reflective wall 28, it is reflected and turned and is blown up while facing the center of the furnace 21.
It falls to the top of the moving bed in the center, is circulated again as described above, and a part of the fluid medium reaches the reflecting wall 2.
8 and pours into the boiler room 29. The fluidized medium that has entered the boiler room 29 is fluidized by the fluidized gas 3 blown from the air diffuser 32.
1, a descending moving layer is formed that gradually descends with gentle flow, and after heat exchange with the heat exchanger tubes, it is refluxed into the furnace 21 through the opening 33.

The mass velocity of the fluidizing gas 31 ejected from the diffuser 32 in the boiler room 29 is selected to be 0.5 to 3 Gmf, preferably 0.5 to 2 Gmf (here, 1 Gmfb is the fluidization starting mass velocity). The amount of flowing gas supplied to the diffuser 32 is mainly regulated by the flow rate control valve V ₁ on the upstream side of the diffuser. Further, the amount of fluidized air supplied from the aeration device 32 to the fluidized bed is regulated by a flow rate control valve V ₂ on the downstream side of the aeration device. That is, when the control valve _V2 is opened, the passage resistance of the fluidized bed is as large as several hundred mmAq or more, so that the gas easily escapes to the downstream side, and the flow rate gas amount supplied to the heat recovery section becomes almost zero. At this time, if there is a fluidized bed adjacent to the diffuser 32, it is subjected to a fluctuating pressure, albeit in a significantly attenuated form, due to the fluidized gas of the fluidized bed. If the surrounding gas pressure and the gas pressure inside the aeration tube are exactly the same, air will not be supplied from the aeration tube to the fluidized bed. When the gas pressure within the diffuser tube is higher than the surrounding gas pressure, gas is supplied from the diffuser tube to the heat transfer section. If the aeration air volume is adjusted by adjusting the opening of the control valve V ₂ downstream of the gas diffuser pipe supply, the difference in air volume between supply and passage will be adjusted to the fluidized bed when the internal pressure of the diffuser is higher than the surrounding gas pressure by the fluidized gas blowing pressure loss. will be supplied. Therefore, the effect of preventing the fluidizing medium from entering the diffuser pipe can be easily obtained by supplying at least a small amount of fluidizing gas. Even if the fluid medium enters the diffuser pipe, since the passing air volume is close to the supply air volume, it will be discharged along with the passing gas, so it will not block the pipe line.

In this way, the amount of fluidizing gas supplied to the fluidized bed can be adjusted as desired, and gas blowing is not hindered by the intrusion of the fluidizing medium. Note that the flow rate of gas handled by the flow rate control valves V ₁ and V ₂ on the upstream and downstream sides of this diffuser pipe is relatively large over the entire blowing air volume range, so it is easy to adjust the amount of fluidized gas supplied to the fluidized bed section. . That is, the upstream flow rate control valve V ₁ of the aeration pipe always handles the maximum amount in the fluidizing gas amount fluctuation region of the heat transfer section. On the other hand, in the flow control valve V ₂ on the downstream side of the diffuser pipe,
In a state where the amount of fluidizing gas in the heat transfer section is small and delicate flow rate adjustment is required, the flow rate to be handled is large and adjustment using a valve is relatively easy. When the flow rate handled by this control valve is small, that is, the amount of fluidized gas supplied from the diffuser pipe to the heat transfer section is large, the flow rate adjusted by this control valve has a relatively small effect on the amount of fluidized gas. Therefore, it is easy to adjust the amount of fluidizing gas.

In addition, in order to form one of two or more adjacent fluidized beds in a fluidized bed that accompanies combustion, the entrained diffused The fluidized medium that has entered the air device can be returned to the fluidized bed, and the total amount of air supplied into the device can be kept constant regardless of fluctuations in the amount of air blown into the fluidized bed alone. In other words, the total amount of combustion air introduced into the entire device is generally fluidized air in the combustion section, fluidized air in the heat transfer section, and secondary air, and the total amount of combustion air is It is preferable to adjust each amount of air to be optimal, and it is preferable to adjust the amount of air to be optimal. It is preferable to maintain the value accordingly. one of two or more adjacent fluidized beds
When changing the amount of fluidizing air supplied to the furnace, the total air amount can always be kept constant by introducing the air downstream of this diffuser into the furnace and using it as secondary air. Note that this also returns the heat taken away by the air diffuser, so there is no waste. Furthermore, it is better to control the flow rate control valves upstream and downstream of the diffuser pipe using measured values such as the amount of evaporation in a fluidized bed having a heat recovery device, or the oxygen concentration in the furnace in a fluidized bed involving combustion. In other words, the optimum amount of air as the total amount of secondary air and heat transfer fluidizing air is calculated from the oxygen concentration in the furnace, fuel supply amount, etc., and the flow rate is adjusted by controlling the flow rate control valve on the upstream side of the air diffuser pipe. Stable fuel management can be performed. In addition, the amount of heat to be recovered in the heat transfer section of the boiler can be detected from the steam pressure, fluidized medium temperature, etc., and the amount of heat recovery can be increased or decreased by adjusting the flow rate control valve on the downstream side of the diffuser pipe. Evaporation amount control can be performed with high responsiveness. With these controls,
Optimal combustion conditions can be obtained at any boiler load.

The fluidized medium poured onto the boiler chamber 29 is composed of a large number of wakes (a type of wake) that are continuously generated and burst, especially in the parts of the combustion chamber in the furnace 21 where the mass velocity is relatively high at both side edges. The origin of the heat generation is the fluidized medium that is blown up to the outside of the fluidized bed in large quantities due to the rupture of bubbles (bubbles that occur within the fluidized bed), so the amount of circulation is never insufficient for the amount of heat that is to be obtained. Note that by extending the reflecting wall 28 toward the furnace center, the amount of fluidized medium entering the boiler chamber 29 can be increased, and by increasing the amount of fluidizing gas 23 in the air chambers 24 and 26. Can be adjusted. Furthermore, heat transfer within the boiler chamber 29 involves not only heat transfer through direct contact with the fluid medium, but also heat transfer using gas as a medium, which rises while vibrating violently and irregularly due to the flow of the fluid medium. In contrast to normal contact heat transfer between a gas and a solid, the latter has almost no boundary layer on the surface of the solid that impedes heat transfer, and the fluidized media are well agitated by the flow, so they are stationary. Unlike sand, etc., heat transfer within the powder becomes negligible, and it exhibits extremely high heat transfer characteristics. Therefore, a fluidized bed boiler can have a heat transfer coefficient that is ten times higher than that of a normal combustion gas boiler.

Normally, non-combustible materials sink to the bottom of the furnace, and the non-combustible materials discharge port 3
9 and are discharged by the screw conveyor 40. However, items that are light in weight relative to their projected area, such as empty cans, are agitated by the movement of the fluidized medium and are blown up higher than the surface of the fluidized bed. A screen (not shown) may also be provided so that the information may be removed.

It is also preferable to provide a partition 50 in order to prevent discharge of the fluidized medium from the boiler chamber 29 to the incombustible material discharge port 39 due to a short circuit, and to effectively return the medium after heat transfer to the fluidized bed that is the combustion chamber. This partition 5
0 may be in the form of a plate attached to the air diffuser pipe forming the air diffuser 32 with a band or the like, or it may be formed using the furnace wall as in the first illustrated example.

Furthermore, by making the upper part of the reflecting wall 28 triangular, it is advantageous to increase the section modulus and form a structure as a beam, and the mounting structure is simple and the weight of the medium in the boiler room 29 can be supported. .

Furthermore, some or all of the reflective wall 28, the air diffuser 32, the partition 50, etc. may be heat resistant, thermal shock resistant,
It is preferable to use ceramics that have properties such as wear resistance and mechanical shock resistance. Various types of ceramics can be selected and used as appropriate, but silicon carbide is advantageous because it does not require replacement for a long period of time. .

〔Effect of the invention〕

In the present invention, the aeration device is a pass-through type, and flow control valves are provided on the upstream and downstream sides of the aeration device, and by adjusting the flow rate, the gas supplied to the aeration device can be blown into the fluidized bed. The amount of gas that passes through the aeration device is increased or decreased, and a certain amount or more of gas flows into the aeration device in any operating state, thereby achieving a cooling effect of the aeration device. Therefore, even when fluidizing gas is not supplied to the heat recovery section, overheating can be prevented, the diffuser can be constantly cooled, troubles caused by fluidized medium entering the diffuser can be prevented, and the amount of supplied air can be easily adjusted. , it is possible to easily control the amount of heat recovery by combustion control and the amount of flowing air in the heat transfer section. It enables smooth control of fluidized bed temperature management, combustion management to maintain a constant air excess ratio, etc., and easily brings out the various features of fluidized bed equipment such as fluidized bed boilers, and further promotes their practical use. This has the effect of making it easier to recommend.

[Brief explanation of the drawing]

Fig. 1 is an overall vertical sectional view showing one embodiment of the present invention, Fig. 2 is a view taken along the line A-A in Fig. 1, Fig. 3 is a relationship diagram between valve opening degree and flow rate, and Fig. 4 The figure shows the downstream control valve
Figure 5 is a diagram showing the relationship between V ₂ and flow rate, Figure 5 is a diagram showing the relationship between flow rate and heat transfer coefficient, Figures 6 and 7 are longitudinal cross-sectional views of parts of other embodiments, and Figure 8 is a diagram showing the relationship between V 2 and flow rate. FIG. 1 is a system explanatory diagram showing an example of control using the present invention. 21...furnace, 22...dispersion plate, 23...fluidizing gas, 24, 25, 26...air chamber, 27...forced blower, 28...reflection wall, 29...boiler room,
30...Blower, 31...Fluidization gas, 32...
air diffuser, 32 ₁ ... nozzle, 33... opening,
34...Heat receiving fluid, 35...Heat transfer tube, 36...2
Next air supply port, 37, 38...detector, 39...
Nonflammable material discharge port, 52... Concentration detector, 53, 56
...Flowmeter, 54...Detector, 55...Integration indicator, 57...Raw material input port, 59...Air/water drum,
58...Exhaust gas outlet, _V1 , _V2 ...Flow control valve.

Claims (1)

[Claims] 1. In a fluidized bed device that fluidizes a fluidized medium to form a fluidized bed using fluidized gas supplied upward from the bottom, a fluidized gas blower that supplies fluidized gas to the fluidized bed. The air diffuser has a structure that allows the fluidizing gas to pass through within the fluidized bed, and is provided with a fluidizing gas supply amount adjustment mechanism and a fluidizing gas passing amount adjustment mechanism to the air diffuser. Aeration device for fluidized bed equipment. 2. The fluidizing gas blowing diffuser is a diffuser pipe having a plurality of gas blowing nozzles, and has an opening for mixing the fluidizing gas that has passed through the diffuser with the gas generated from the fluidized bed. The air diffuser according to claim 1, wherein the air diffuser is provided at a position within the fluidized bed. 3. The air diffuser has a detector that detects the amount of fluidizing gas supplied to the air diffuser, and is equipped with a fluidizing gas supply amount adjustment mechanism that can control this gas amount to a set value equal to or higher than a certain value. Claim 1
The air diffuser according to item 1 or 2. 4. A patent claim in which the air diffuser is disposed within a fluidized bed of a fluidized bed heat recovery device, and controls the amount of fluidized gas passing through the air diffuser section to adjust the amount of recovered heat. The air diffuser according to any one of the ranges 1 to 3. 5. The air diffuser is disposed within the fluidized bed of the fluidized bed heat recovery device, and is equipped with a detector for detecting the amount of recovered heat, and is configured to keep the amount of recovered heat constant based on the detected value of the detector. Claims 1 to 3 are for controlling the flow rate adjustment mechanism of the fluidizing gas passing through the diffuser section.
The air diffuser described in any one of Item 4. 6. The aeration section is installed in the fluidized bed of a fluidized bed incinerator, and includes a detector for detecting the oxygen concentration in the combustion exhaust gas of the incinerator, and a detector that detects the oxygen concentration based on the detected value of the detector. 5. The air diffuser according to any one of claims 1 to 4, wherein the setting value of the fluidizing gas supply amount adjustment mechanism control is adjusted so that the amount of fluidizing gas supplied is constant. 7. The aeration section is composed of a group of aeration tubes having an outgoing path and an incoming path communicating as a gas passage, and the outgoing path,
In addition to providing a blowing nozzle on either of the return routes,
The dispersion according to any one of claims 1 to 6, wherein the outward path is connected to a fluidizing gas supply amount adjustment mechanism, and the return path is connected to a fluidizing gas passage amount adjustment mechanism. Air device. 8. The aeration section is composed of a group of aeration tubes penetrating the fluidized bed, each of the aeration tubes is provided with a nozzle for blowing fluidizing gas into the fluidized bed below the aeration tube, and one end of the tube is provided with a nozzle for blowing fluidizing gas into the fluidized bed. 7. The air diffuser according to claim 1, wherein the diffuser is connected to a fluidizing gas supply amount adjusting mechanism, and the other end is connected to a fluidizing gas passing amount adjusting mechanism. 9. The aeration section is divided into a heat recovery section in which the upper and lower parts of the fluidized bed are communicated by a partition wall, and a combustion section that supplies combustible materials, and the unit area of the combustion section is at least in the vicinity of the partition wall. The flow rate of the fluidized gas per unit area is set to be larger than the flow rate of the fluidized gas per unit area of the heat recovery section to cause the fluidized medium of the combustion section to flow into the heat recovery section beyond the partition wall, and The dispersion according to any one of claims 1 to 8, which is provided in the heat recovery section of a fluidized bed in which the fluidized medium of the heat recovery section is returned to the combustion section from the lower part of the partition wall. Air device.