JPS6329108A - Diffuser in fluidized bed equipment - Google Patents

Abstract

PURPOSE:To prevent overheat by cooling a diffuser and make maintenance easy, and control of the title equipment by a method wherein a diffusing part for blowing fluidizing gas is made to have a structure through which fluidizing gas is able to pass in a fluidized bed and control mechanisms for the fluidizing gas supply quantity and the fluidizing gas passing quantity to the diffuser are installed and gas having a constant volume or more is forced to flow in the diffuser. CONSTITUTION:The fluidizing gas quantity supplied to a diffuser 32 is controlled mainly by a flow control valve V1 installed at the upper stream of the diffuser. The fluidizing air quantity supplied to a fluidized bed is controlled by a flow control valve V2 at the down stream of the diffuser. At that time, when there is an adjacent fluidized bed around the diffuser, the bed is subjected to the changed pressure though the pressure is brought into a largely reduced form caused by the fluidizing gas. When the gas pressure in a diffusing pipe is higher than that of the surrounding gas, the gas is supplied to a heat transfer part from the diffusing pipe. When a very small amount of the fluidizing gas is supplied even at the lowest value by controlling the opening degree of the valve V2 installed at the down stream of the gas diffusing pipe, the effect of preventing the invasion of fluidizing medium into the diffusing pipe is easily obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an incinerator or combustible material having 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]

In conventional fluidized bed equipment, there is a fluidized bed boiler or heat recovery equipment (Japanese Patent Application No. 61-888) which some of the present inventors have already applied for.
0, Patent application 1986-16726, Patent application 61-5255
A diffuser section for introducing fluidizing gas into the fluidized bed to flow the fluidized medium, such as the heat transfer section 9), is used. The diffuser for supplying a fluidizing gas such as air to this fluidized bed simply introduces the fluidizing gas into the fluidized bed.

[Problem that the invention seeks to solve]

However, when applied to the air diffuser for the heat recovery section of a fluidized bed boiler or heat recovery device devised by the present inventors, for example, to an aeration pipe, the amount of heat transferred from the heat recovery section within the fluidized bed is reduced. When reducing the amount of fluidizing gas or stopping the supply for purposes such as
The sand was overheated by the temperature of the sand, which reached ℃, causing deformation and corrosion of the air diffuser pipes, leading to concerns that the lifespan of the air diffuser pipes would be shortened.

In addition, when two or more fluidized beds are formed in the same device, if the amount of fluidized gas blown into one fluidized bed is extremely reduced, the flow will be affected by the flow of the other fluidized bed and the gas will flow inside the diffuser tube. There was a risk that media could enter and clog the diffuser pipe. For this reason, the diffuser needs to have a special structure that takes into account countermeasures against the infiltrating fluid medium, resulting in extremely complex and commercially expensive problems.

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 the region of low fluidized gas amount, the diffuser tube The amount of gas supplied to the area becomes significantly smaller.

Therefore, in the normal flow rate adjustment based on the pressure drop of the passing gas, it is difficult to control a minute flow rate due to the characteristics, and it is difficult to set the flowing gas amount to an arbitrary value.

Furthermore, when applied to a fluidized bed involving combustion, fluidized air
At the same time, it is also combustion air, so if the amount of fluidized air supplied to the fluidized bed is varied in order to obtain the necessary fluidization state, the amount of air traveling to the entire fluidized bed will vary accordingly, resulting in an excess of air. This was a problem because the combustion rate fluctuated, making it impossible to maintain the optimum view 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 purpose of this invention is to provide an air diffuser in a flow N device 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. The aeration part for blowing the fluidizing gas that supplies the gas has a structure that allows the fluidized gas to pass through within the fluidized bed,
The present invention provides an aeration device for a fluidized bed apparatus, characterized in that a mechanism for adjusting the amount of fluidizing gas supplied to the aeration section and a mechanism for adjusting the amount of fluidizing gas passing through the aeration section are provided.

〔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 in a chevron-shaped cross section (roof-like) that is almost symmetrical with respect to the roof. The fluidizing gas 23 sent from the forced air blower 27 passes through the air chambers 24, 25.26 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.

Directly above the air chambers 24 and 26 on both side edges, a fluidizing gas 2 is placed.
A partition wall 28° with a board-shaped reflecting wall 28 is provided as a reflecting wall that blocks the upward flow path of 3 and reflects and diverts the fluidizing gas 23 toward the center of the furnace 21.
A boiler room 29 is formed between a certain partition wall 28° and the furnace wall, and during operation, a part of the fluidized medium crosses the reflecting wall and enters the boiler room 2.
It's designed to fit into 9 in a similar way.

Further, at a level higher than the bottom of the furnace in the lower part of the boiler room 29, an aeration device 32 made of, for example, a dispersion pipe is provided, which blows out the fluidizing gas 31 from the air blower a30 from the aeration device 32. There is an opening 3 near the air diffuser 32.
3 is provided, and the fluid medium that has entered the boiler room 29 is
Depending on the operating conditions, it settles while forming a moving bed or a fluidized bed, either continuously or intermittently.

Further, heat transfer tubes 35 are disposed inside the boiler chamber 29 or on the wall surface thereof, through which the heat receiving fluid 34 is passed, so as to perform heat exchange with the fluidized medium.

As shown in FIG. 2, an upstream flow control valve V and a downstream flow control valve 2 are provided in the piping for the fluidizing gas 31 connected to the aeration device 32, and the piping is connected to the furnace wall. The secondary air supply port 36 is connected to the secondary air supply port 36 which is opened to the side. Flow control valve V,,
The relationship between Vt and flow rate is as shown in Figure 3, but if the opening degree of the flow rate control valve 1 on the upstream side of the diffuser pipe is kept constant, the supplied flow rate as shown in Figure 4 is obtained. In particular, the controllability when using a small 2Jt firefly is excellent. 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 a diffuser pipe having a plurality of gas blowing nozzles 321, and mixes the fluidizing gas 31 that has passed through the diffuser into the gas generated from the fluidized bed. A fluidizing gas supply amount adjustment device that is provided at a position within the flow station and has a detector 37 that detects the amount of fluidizing gas supplied to the aeration section, and is capable of controlling this gas amount to a set value above a certain value. As a mechanism, it is configured in relation to the upstream flow rate control valve V1. In addition, the upstream flow rate control valve 2 is designed 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 installed in the piping so as to function as a mechanism for adjusting the amount of flowing gas passing through the aeration section. It's Nishide.

Note that when the diffuser 32 of the diffuser section is installed in the fluidized bed of the fluidized M 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, it is equipped with 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 setting value of the fluidizing gas supply i adjustment mechanism control so that the oxygen concentration is constant according to the detected value of the detector, and the fluidizing gas passage N adjustment mechanism may be controlled as necessary. They can also be used together for control.

In the example shown in FIG. 6, the air diffuser 32 has an outgoing path 31. which is connected as a gas passage. In other words, it is a diffuser tube having an inner and outer double pipe structure, and its insertion tube is connected to an outgoing path 311 and an incoming path 31g at its tip, and the aeration part is made up of an insertion tube group having an outgoing path and a returning path 31□. , the outgoing path and the incoming path are connected at the tip of each insertion tube, and the outgoing path 311 and the incoming path 3
1□ or both are provided with a fluidizing gas blowing nozzle into the fluidized bed, and the outgoing path 31. is t of the fluidizing gas supply amount adjustment mechanism.
The return path 31□ is connected to the control valve V2 of the fluidizing gas passage amount control mechanism. Then, air is supplied to the inner pipe of the aeration pipe and is discharged through between the outer pipe and the inner pipe. The insertion part is slightly lowered and the tip is sloped 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, a tube plate 31. Divided into two parts, outward route 31. and the return trip 31□, and the outbound trip 31. may be connected to the fluidizing gas supply amount adjusting mechanism, and the return path 31□ may be connected to the fluidizing gas passing amount adjusting mechanism.

Furthermore, in the example shown in FIG. 8, the diffuser 32 of the diffuser section is composed of a group of diffuser tubes penetrating the fluidized bed, and a nozzle for blowing fluidizing gas into the fluidized bed is provided below each diffuser tube. 32
．． One end of the pipe is connected to the control valve V1 of the fluidizing gas supply amount regulating mechanism, and the other end is connected to the regulating valve V2 of the fluidizing gas passage amount regulating mechanism.

That is, the diffuser pipe upstream flow ffi control valve (1) 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 flow meter 53, and the diffuser pipe downstream flow control valve (2) is controlled from the values of the temperature detector 54 of the fluidized bed and the integration indicator 55 of the boiler via the indicator adjustment flowmeter 56 so that the amount of heat recovered in the heat transfer section becomes the 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, a fluidized bed in which the fluidized medium is made to flow by the /X fluidizing gas containing oxygen as a component, which is blown upward from the bottom. The combustion section is divided into a heat recovery section whose upper and lower parts are communicated with each other by a partition wall, and a combustion section which supplies combustible materials. The fluidizing gas blowing air volume per unit area is set to be larger than that of the fluidizing gas blowing air volume, so that the fluidized medium of the combustion section flows into the heat recovery section over the partition wall, and the fluidized medium of the heat recovery section is introduced from the lower part of the partition wall. It is effectively used in fluidized bed heat recovery equipment where the heat is returned to the combustion section.

In the figure, 57 is a raw material inlet provided at the top of the furnace 21, and 59
is an air/water drum disposed near the exhaust gas outlet 58, which forms a circulation path with the heat transfer tube 35 in the boiler chamber 29. Further, 39 is an incombustible material discharge port connected to both sides of the distribution plate 22 at the bottom of the furnace 21, 40 is a screw conveyor having a screw 41 disposed in a reverse thread direction, and 42 is a motor.

To explain using the example shown in FIG. 1, the combustible material F introduced into the furnace 21 from the raw material input port 57 burns 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 narrow at the top, but becomes slightly wider at the bottom due to the effect of the slope of the dispersion plate 22, and part of the bottom reaches above the air chambers 24 and 26 on both side edges. Therefore, it is blown up by the injection of the fluidizing gas 23 at a large mass velocity. 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,
As will be described later, the fluidized medium from the fluidized bed is replenished and deposited, 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 it hits the reflective wall 28 and is reflected and flipped up toward the center of the furnace 21, falling onto the top of the moving bed in the center and being blown up again. While being circulated as described above, a portion of the fluid medium spills over the reflecting wall 28 into the boiler chamber 29. The fluidized medium that has entered the boiler room 29 is blown into the fluidized gas 31 from the diffuser 32.
A descending moving layer is formed that gradually descends with gentle flow, and after heat exchange with the heat transfer tube,
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 chamber 29 is 0.5 to 3 Gmf, preferably 0.5 to 2 G+! If (where IGrin' is the mass velocity at which fluidization starts) is selected. Then, this diffuser 3
The amount of fluidized gas supplied to the air diffuser 2 is mainly regulated by the flow rate control valve v1 on the upstream side of the diffuser. Further, the amount of fluidized air supplied from the air diffuser 32 to the fluidized bed is regulated by the flow rate control valve v2 on the downstream side of the air diffuser. In other words, this control valve V2
When the fluidized bed is opened, the passage resistance of the fluidized bed is as large as several hundred −■^q or more, so it easily escapes to the downstream side, and the amount of fluidized gas supplied to the heat recovery section becomes almost zero. At this time, if there is a fluidized bed adjacent to the diffuser, it is subjected to fluctuating pressure, albeit in a greatly attenuated form, due to the fluidizing gas of this 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 lower than the surrounding gas pressure, gas is supplied from the diffuser tube to the heat transfer section. If the passing air volume is adjusted by adjusting the opening of the control valve v2 downstream of the gas diffuser pipe, the air volume difference between the supply and passing air flows into the fluidized bed when the internal pressure of the diffuser is higher than the surrounding gas pressure by the fluidized gas blowing hole pressure. 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 air diffuser pipe, i! Since the amount of air flowing through li is large and close to the amount of supply it, it is discharged along with the passing gas, so there is no possibility of blocking the pipe line.

In this way, the amount of fluidizing gas supplied to the fluidized bed can be adjusted arbitrarily, and gas blowing is not hindered by the infiltration of the fluidizing medium.
Note that the flow rate of gas handled by the flow rate control valves V, , V on the upstream and lower sides of the diffuser pipe is relatively large over the entire blown volume, so the amount of flowing gas supplied to the tidal layer section must be adjusted. is easy.

That is, the upstream flow rate control valve (1) of the air diffuser pipe always handles the maximum amount in the fluidizing gas amount fluctuation range of the heat transfer section. On the other hand, the flow rate control valve V on the downstream side of the diffuser pipe handles a large flow rate when the amount of fluidizing gas in the heat transfer section is small and delicate flow rate adjustment is required, and the valve can relatively easily adjust the flow rate. When the flow rate handled by this control valve is small, that is, when the amount of fluidizing 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 fluidizing gas amount. jFI of fluidizing gas amount as
f is easy.

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 air amount to be optimal, and the theoretical air amount is 1.1 to 1, which is the air amount equal to the amount of oxygen consumed in normal combustion.
．． It is preferable to maintain the value at a value corresponding to the combustible material and combustion device of about 4 times (excess air ratio). When changing the amount of fluidizing air supplied to one of two or more adjacent fluidized beds,
If the downstream air of this air diffuser is introduced into the furnace and used as secondary air, the total amount of air can be kept constant at all times.

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, the amount of fuel supplied, etc., and the flow rate is adjusted by controlling the flow rate control valve on the downstream side of the diffuser pipe. Stable combustion 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. These controls make it possible to obtain optimal combustion conditions 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 in the parts of the combustion chamber in the furnace 21, especially in the parts of the combustion chamber on both sides where the mass velocity is relatively high. 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. The amount of fluidized medium entering the boiler chamber 29 can be increased by extending the reflecting wall 28 toward the furnace center, and adjustment can also be made by increasing the visibility of the fluidized gas 23 in the air chambers 24 and 26. .

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. The latter has almost no boundary layer on the solid surface that impedes heat transfer compared to normal contact heat transfer between gas and solid.
In addition, since the fluidized media are well agitated by the flow, unlike static sand, heat transfer within the powder becomes negligible, and exhibits extremely high heat transfer characteristics. Therefore, the fluidized bed boiler It can have a heat transfer coefficient that is 10 times or more compared to a combustion gas boiler.

Normally, non-combustible materials sink to the bottom of the furnace, are collected at the non-combustible material discharge port 39, and are discharged by the screen conveyor 40.However, if the weight is light relative to the projected area, such as empty cans, the fluidized medium A screen (not shown) can also be provided because the air may be blown up higher than the surface of the 2it dynamic layer due to the movement of the air.

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 D39 due to a short circuit, and to effectively return the medium after heat transfer to the flow 01 layer which is the combustion chamber. This partition 50 may be a plate-shaped one attached with a band or the like to the diffuser pipe forming the diffuser U32,
Alternatively, it can also 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 beam structure, and the mounting structure can receive the weight of the medium in the boiler room 29 with an oil layer. .

Furthermore, it is preferable that some or all of the reflective wall 28, the air diffuser 32, the partition 50, etc. be made of ceramic having properties such as heat resistance, thermal shock resistance, abrasion resistance, and mechanical shock resistance. Although various materials can be selected and used as appropriate, silicon carbide is advantageous because it does not require replacement for a long period of time.

〔Effect of the invention〕

This invention diffuses air! j The device is a pass-through type, and flow control valves are provided on the upstream and downstream sides of the diffuser, and by adjusting the flow rate, the fluidized gas is blown into the fluidized bed, and the gas supplied to the diffuser is This is done by increasing or decreasing the amount of gas that passes through the air diffuser, so that a certain amount or more of gas flows into the diffuser regardless of the operating state, and the cooling effect of the diffuser can be obtained. 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 degassing device can be prevented, and the amount of supplied air can be easily adjusted. The amount of heat recovered can be easily controlled by combustion control and the amount of flowing air in the heat transfer section.The amount of heat recovered and It makes it possible to smoothly control fluidized bed temperature management, combustion management to keep the excess air ratio constant, and easily brings out the various features of fluidized bed equipment such as fluidized bed boilers, and further promotes their practical use. It has the effect of making it easier.

[Brief explanation of drawings]

Fig. 1 is an overall vertical cross-sectional view showing one embodiment of the present invention;
The figures are a view taken along the line A-A in Fig. 1, Fig. 3 is a diagram showing the relationship between valve opening and flow rate, and Fig. 4 is a diagram showing the relationship between the downstream control valve ■2 and i! Figure 5 is a relationship diagram with AI, Figure 5 is a relationship diagram between flowing air amount and heat transfer coefficient, Figures 6 and 7 are longitudinal sectional views of parts of other embodiments, and Figure 8 is a diagram of the present invention. It is a system explanatory diagram showing an example of control using. 21... Furnace, 22... Dispersion plate, 23... Fluidizing gas, 24.25.26... Air chamber, 27... Forced blower, 28... Reflecting wall, 29... Boiler room, 30・
...Blower, 31...Fluidizing gas, 32...Diffuser, 32,...Nozzle, 33...Opening, 34...
・Heat receiving fluid, 35...Heat transfer tube, 36...Secondary air supply port, 37.38...Detector, 39...Incombustible material discharge port, 52...Concentration detector, 53.56 ...Flow rate needle,
54...Detector, 55...Integration indicator, 57...
Raw material input port, 59...Air/water drum, 58...Exhaust gas outlet, V,,V,...Flow rate 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 that supplies the fluidized gas to the fluidized bed. The blowing diffuser has a structure that allows the fluidizing gas to pass through within the fluidized bed, and is provided with a mechanism for adjusting the amount of fluidizing gas supplied to the diffuser and a mechanism for adjusting the amount of fluidizing gas passing through. Aeration device for fluidized bed equipment. 2. The fluidizing gas blowing diffuser is a diffuser pipe having a plurality of gas blowing nozzles, and the fluidizing gas that has passed through the diffuser is mixed into the gas generated from the fluidized bed. The air diffuser according to claim 1, which is provided at a location. 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 the amount of gas to a set value above a certain value. An air diffuser according to claim 1 or 2. 4. A patent in which the aeration section is arranged in a fluidized bed of a fluidized bed heat recovery device, and the amount of recovered heat is adjusted by controlling a mechanism for adjusting the amount of fluidized gas passing through the aeration section. An air diffuser according to any one of claims 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. The air diffuser according to any one of claims 1 to 4, wherein the air diffuser fluidizing gas passage amount adjusting mechanism is controlled to control the air diffuser fluidizing gas passage amount adjusting mechanism. 6. The aeration section is installed in the fluidized bed of the fluidized bed incinerator, and includes a detector that detects 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. The air diffuser according to any one of claims 1 to 4, wherein a setting value of the fluidizing gas supply amount adjustment mechanism control is adjusted so that the concentration 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 a blowing nozzle is provided on either the outgoing path or the incoming path, and the outgoing path is connected to a fluidizing gas supply amount adjustment mechanism. claim 1, wherein the return path is connected to a fluidizing gas passage amount adjusting mechanism.
The air diffuser according to any one of items 1 to 6. 8. The aeration section is composed of a group of aeration tubes penetrating the fluidized bed, each of which 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 material, and the combustion section has at least a per unit area in the vicinity of the partition wall. The fluidizing gas blowing air volume is set to be larger than the fluidizing gas blowing air volume 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 Claims 1 to 3 are 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.
An air diffuser according to any one of Item 8.