JP2021025699A - Collection method of fluid medium in fluid bed furnace - Google Patents

Abstract

To provide a method which can efficiently collect a valuable metal contained in a refuse in a fluid bed furnace.SOLUTION: In a collection method of a fluid medium in a fluid bed furnace, the fluid bed furnace comprises: a furnace main body; the fluid medium filled into the furnace main body; and a furnace bottom plate in which a withdrawal port for withdrawing the fluid medium to the outside of the furnace main body is formed, and which is inclined downward at an angle smaller than a repose angle of the fluid medium toward the withdrawal port. In the fluid bed furnace for burning or gasifying a refuse containing a valuable metal in a state that the fluid medium circulates, the method for collecting the fluid medium from the furnace main body when the fluid bed furnace is stopped comprises: a withdrawal process for withdrawing the fluid medium which is filled in the furnace main body to the outside of the furnace main body through the withdrawal port; and a collection process for collecting the fluid medium remaining on the furnace bottom plate after the withdrawal process in a state that the remaining fluid medium is separated from the fluid medium which is withdrawn from the inside of the furnace main body in the withdrawal process.SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for recovering a fluidized medium in a fluidized bed furnace.

Conventionally, as described in Patent Documents 1 and 2, a fluidized bed incinerator that incinerates various wastes in a state where a fluidized medium such as sand is flowing, or a fluidized bed gasification that gasifies the waste. The furnace is known. These fluidized bed furnaces are provided with a circulation mechanism for taking out the fluidized medium from the furnace, separating the fluidized medium from the incombustible material, and then returning the fluidized medium to the furnace.

Patent Document 1 describes a method for treating the bottom residue of a fluidized bed gasifier. In this method, metal and non-metal components are removed from the bottom residue discharged from the fluidized bed gasifier. The recovered fluidized bed is returned to the furnace, and the recovered non-metal content is slagged in the melting furnace. Patent Document 2 describes a sand classification device and sand circulation as a circulation mechanism for separating incombustibles from a mixture of fluidized sand and incombustibles discharged from the bottom of a fluidized bed gasifier and returning only the fluidized sands to the furnace. Elevators and those equipped with are listed.

Japanese Patent No. 3909514 Japanese Patent No. 4321823

Waste that is incinerated by a fluidized bed incinerator or gasified by a fluidized bed gasifier contains a small amount of precious metals such as gold and silver or heavy metals such as lead and zinc. There is. In Patent Documents 1 and 2, it is difficult to efficiently recover valuable metals contained in such waste, and the present inventors have focused on this problem.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method capable of efficiently recovering valuable metals contained in waste in a fluidized bed furnace.

In the method for recovering a flow medium in a flow bed furnace according to one aspect of the present invention, a furnace body, a flow medium filled in the furnace body, and an outlet for extracting the flow medium to the outside of the furnace body are provided. A furnace bottom plate that is formed and inclines downward at an angle smaller than the rest angle of the flow medium toward the outlet is provided, and waste containing valuable metals is incinerated while the flow medium is flowing. In a gasifying flow bed furnace, this is a method of recovering the flow medium from the inside of the furnace body when the flow bed furnace is stopped. In this recovery method, the flow medium filled in the furnace body is extracted to the outside of the furnace body by gravity through the extraction port, and the extraction step remains on the bottom plate after the extraction step. It is provided with a recovery step of recovering the flow medium in a state of being separated from the flow medium extracted from the furnace body in the extraction step.

In the above recovery method, after stopping the fluidized bed furnace, first, the fluidized medium filled in the furnace main body is taken out of the furnace main body through an extraction port (extraction step). At this time, since the inclination angle of the furnace bottom plate is smaller than the angle of repose of the flow medium, not all the flow medium filled in the furnace body is taken out of the furnace in the above extraction step, and a part of the flow medium is not extracted. Remains on the bottom plate.

As a result of diligent research, the present inventors have newly discovered that the fluid medium remaining on the bottom plate after the extraction process contains a high concentration of valuable metals derived from waste as described above. .. Therefore, in the method for recovering the fluidized bed in the fluidized bed furnace of the present invention, based on the above findings, the fluidized medium remaining on the bottom plate after the extraction step is extracted to the outside of the furnace in the extraction step. It is separately collected in a state separated from the medium without being mixed with the medium (recovery step). This makes it possible to recover only the fluid medium containing a high concentration of valuable metal, and then efficiently recover the valuable metal derived from waste by separating the valuable metal from the recovered fluid medium. be able to.

The method for recovering the fluidized medium in the fluidized bed furnace may further include a separation step for separating the valuable metal from the fluidized medium recovered in the recovery step.

According to this method, the valuable metal separated from the flow medium can be used for various purposes.

In the method for recovering a fluidized medium in the fluidized bed furnace, the fluidized bed furnace is a circulation mechanism for returning the fluidized medium extracted to the outside of the furnace body to the furnace body, and transports the fluidized medium. The circulation mechanism may further include a unit and a storage tank for storing the fluidized medium transported by the transport unit. In the extraction step, the flow medium extracted to the outside of the furnace body may be conveyed by the conveying unit and supplied to the storage tank. In the recovery step, the flow medium remaining on the bottom plate of the furnace may be discharged to the outside of the furnace body and then recovered at a place different from the storage tank.

According to this method, the flow medium remaining on the furnace bottom plate after the extraction step can be recovered in a state of being surely separated from the flow medium extracted to the outside of the furnace in the extraction step.

As is clear from the above description, according to the present invention, it is possible to provide a method capable of efficiently recovering valuable metals contained in waste in a fluidized bed furnace.

It is a figure which shows typically the structure of the fluidized bed furnace in Embodiment 1 of this invention. It is sectional drawing which shows the structure of the air diffuser pipe in the said fluidized bed furnace. It is a top view which shows the structure of the air diffuser pipe in the said fluidized bed furnace. It is a flowchart which shows the procedure of the recovery method of the fluidized medium in the fluidized bed furnace which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the fluidized medium which remained on the furnace bottom plate after the extraction process of the method of recovering a fluidized bed in the said fluidized bed furnace. It is a figure which shows typically the structure of the fluidized bed furnace in Embodiment 2 of this invention.

Hereinafter, a method for recovering a fluidized medium in a fluidized bed furnace according to an embodiment of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
<Composition of fluidized bed gasification and melting furnace>
First, a method for recovering a fluidized medium in a fluidized bed furnace according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 5. First, the configuration of the fluidized bed type gasification melting furnace 1 in which the present recovery method is carried out will be described with reference to FIGS. 1 to 3.

As shown in FIG. 1, the fluidized bed type gasification and melting furnace 1 in the present embodiment mainly includes a fluidized bed type gasification furnace 10, a swirling flow melting furnace 20, and a duct 30. Hereinafter, each of these components will be described.

The fluidized bed gasifier 10 uses, for example, municipal waste, sewage sludge, and various wastes such as automobile crushing residue (ASR: Automobile Shredder Resolution) as combustible gas (carbon monoxide, hydrogen, hydrocarbon, etc.) and unburned. Equipment for thermally decomposing into objects (char) and ash. As shown in FIG. 1, in the fluidized bed gasification furnace 10, the furnace main body 12, the fluidized medium 13 filled in the furnace main body 12, and the outlet 16b for extracting the fluidized medium 13 to the outside of the furnace main body 12b. It mainly has a furnace bottom plate 16 in which the above is formed, and an extraction pipe 15 connected to the extraction outlet 16b.

The furnace body 12 has a cylindrical shape extending in the vertical direction. The furnace body 12 is provided with a supply port 14 for supplying waste into the furnace body 12, an outflow port 11 for allowing flammable gas generated in the furnace body 12 to flow out of the furnace, and a flow medium 13. An introduction port 17 for introducing the fluidized gas (for example, air) for flowing into the air box 18 (the space below the bottom plate 16 in the furnace body 12) is provided, respectively. As shown in FIG. 1, the supply port 14 is provided in a portion of the side portion of the furnace main body 12 above the furnace bottom plate 16. The outlet 11 is provided at the top of the furnace body 12. The introduction port 17 is provided in a portion of the side portion of the furnace main body 12 below the furnace bottom plate 16.

The furnace bottom plate 16 is arranged on the bottom side in the furnace body 12, and the outlet 16b of the flow medium 13 is formed in the central portion thereof. A large number of air diffusers 16a penetrate the peripheral portion of the outlet 16b in the bottom plate 16. Further, as shown in FIG. 1, the furnace bottom plate 16 is inclined downward toward the central outlet 16b, and the inclination angle thereof is smaller than the angle of repose of the flow medium 13. Specifically, the angle of repose of the flow medium 13 is 35 to 40 °, while the inclination angle of the furnace bottom plate 16 is 10 to 30 °. In FIG. 1, the inclination angle of the furnace bottom plate 16 is shown as an angle between the horizontal direction (broken line in FIG. 1) and the lower surface of the furnace bottom plate 16, but the horizontal direction and the upper surface of the furnace bottom plate 16 The angle between them is the same.

2 and 3 show in detail the configuration of the air diffuser 16a. As shown in FIG. 2, each air diffuser pipe 16a has a straight pipe portion 16a1 penetrating the furnace bottom plate 16 in the thickness direction and a U-shaped pipe portion 16a2 connected to the upper end of the straight pipe portion 16a1. There is. The fluidized gas introduced into the air box 18 from the introduction port 17 (FIG. 1) rises in the straight pipe portion 16a1 and then is sent out toward the flow medium 13 from the opening of the U-shaped pipe portion 16a2 (in FIG. 3). Arrow).

The fluidizing medium 13 is fluid sand such as silica sand or olivine sand, and is filled on the bottom plate 16. As a result, as shown in FIG. 1, a fluidized bed (sand layer) having a predetermined thickness is formed on the furnace bottom plate 16. The fluidized bed gasifier 10 treats waste containing valuable metals (for example, gold, silver, copper, lead or zinc) in a fluidized state of the fluidized medium 13.

The extraction pipe 15 is for extracting the flow medium 13 together with the incombustible material to the outside of the furnace body 12. As shown in FIG. 1, the extraction pipe 15 has an upper end portion connected to the extraction port 16b of the furnace bottom plate 16 and a lower end portion located outside the furnace body 12, and has a bottom wall of the furnace body 12. It penetrates the portion and extends vertically from the upper end to the lower end.

The swirl flow melting furnace 20 completely burns the combustible gas and the unburned material while forming the swirl flow 100 of the combustible gas generated in the fluidized bed gasification furnace 10, and the ash accompanied by the combustible gas. It is a furnace that melts. As shown in FIG. 1, the swirling flow melting furnace 20 is provided with an inflow port 21 for flammable gas and a slag port 22 for discharging molten slag formed by melting ash to the outside of the furnace. It has a furnace body 23.

The inflow port 21 is provided at a portion near the top of the side portion of the furnace main body 23, and is connected to the outflow port 11 of the fluidized bed gasification furnace 10 by a duct 30. Further, the slag opening 22 is provided at the bottom of the furnace main body 23. The exhaust gas generated by the combustion of the flammable gas in the swirl flow melting furnace 20 has passed through various facilities (boiler, temperature reducing tower, bag filter, catalytic reaction tower, etc.) arranged after the swirl flow melting furnace 20. Later, it is released into the atmosphere from a chimney (not shown).

The fluidized bed gasifier 10 has a circulation mechanism 40. The circulation mechanism 40 separates the flow medium 13 extracted from the furnace body 12 from the incombustible material and then returns it to the furnace body 12. As shown in FIG. 1, the circulation mechanism 40 includes a extraction screw 41, a classification device 42, a circulation elevator 43 (transport section), a storage tank 44, and first to third transport paths 45, 46, 47. Mainly has.

The extraction screw 41 is for extracting the flow medium 13 together with the incombustible material from the bottom portion of the furnace main body 12 by rotational driving, and is provided at the lower end portion of the extraction pipe 15. The classification device 42 is provided at the downstream end of the extraction screw 41, and separates the flow medium 13 and the incombustible material by a sieve. The incombustible material separated from the flow medium 13 is crushed and then slagged in the swirling flow melting furnace 20 or carried out of the system.

The circulation elevator 43 conveys the flow medium 13 from which incombustibles have been removed by the classification device 42 to a predetermined height. As shown in FIG. 1, an inlet 43A of the flow medium 13 is provided in the lower part of the circulation elevator 43, and the inlet 43A and the outlet 42A of the classification device 42 (the outlet of the flow medium 13) are provided by the first transport path 45. It is connected. An outlet 43B of the flow medium 13 is provided above the circulation elevator 43.

The storage tank 44 is a tank for storing the flow medium 13 carried upward by the circulation elevator 43. As shown in FIG. 1, the upper end of the second transport path 46 is connected to the outlet 43B of the circulation elevator 43, and the storage tank 44 is arranged in the middle of the second transport path 46. As a result, the flow medium 13 transported upward by the circulation elevator 43 can be dropped into the storage tank 44 through the second transport path 46 and stored in the storage tank 44.

Further, as shown in FIG. 1, one end of the third transport path 47 is connected to a portion of the second transport path 46 above the storage tank 44, and the other end is connected to a side portion of the furnace body 12. There is. As a result, the flow medium 13 exiting the outlet 43B of the circulation elevator 43 can be returned to the furnace body 12 through the third transport path 47. Although not shown, the circulation mechanism 40 further has a switching unit (valve or the like) for switching whether the flow medium 13 exiting the outlet 43B of the circulation elevator 43 is guided to the storage tank 44 or the furnace body 12. You may have.

<Recovery method of fluidized bed in fluidized bed furnace>
Next, a method of recovering the fluidized medium in the fluidized bed furnace according to the present embodiment will be described with reference to the flowchart shown in FIG. As described below, this recovery method is a method of recovering the fluidized medium 13 from the inside of the furnace main body 12 when the fluidized bed gasifier 10 is stopped, for example, during maintenance of the fluidized bed gasifier 10.

First, before the maintenance of the fluidized bed gasifier 10, that is, in the steady operation of the fluidized bed gasifier 10 (step S10), the fluidized gas (for example, air) sent by the diffuser pipe 16a causes the fluidized medium 13 to move. The waste is supplied into the furnace body 12 from the supply port 14 in a fluidized state. Then, the waste is thermally decomposed into flammable gas, unburned matter and ash by being heated in the furnace body 12. Here, the waste contains a considerable amount of valuable metals such as precious metals (gold, silver, copper, etc.) and heavy metals (lead, zinc, etc.).

The flammable gas generated in the fluidized bed gasifier 10 flows into the swirling flow melting furnace 20 through the duct 30 together with the unburned material and ash. Then, in the swirling flow melting furnace 20, the combustible gas and the unburned material are completely burned and the ash is melted. During this steady operation, by operating the circulation mechanism 40, the flow medium 13 filled in the furnace body 12 is taken out of the furnace together with the incombustibles, and the flow medium 13 from which the incombustibles have been removed is brought into the furnace body 12. return.

Next, when the maintenance time for the fluidized bed gasifier 10 arrives (YES in step S20), first, the supply of waste to the furnace body 12 is stopped (step S30), and then the flow to the air box 18 is reached. The supply of gasification is also stopped (step S40). After that, a step of extracting the flow medium 13 filled in the furnace body 12 to the outside of the furnace body 12 (extraction step S50) is performed.

In the extraction step S50, the flow medium 13 filled in the furnace body 12 is extracted to the outside of the furnace body 12 by gravity through the extraction port 16b. Specifically, by rotationally driving the extraction screw 41, the flow medium 13 filled in the furnace body 12 is extracted out of the furnace body 12 through the extraction pipe 15.

Then, the flow medium 13 extracted to the outside of the furnace is separated from the incombustible material by the classification device 42, transported upward by the circulation elevator 43, and then stored in the storage tank 44. That is, in the extraction step S50, the flow medium 13 extracted from the furnace body 12 is not returned to the furnace body 12, but is all stored in the storage tank 44.

FIG. 5 schematically shows the inside of the furnace body 12 (the state near the bottom plate 16) after the extraction step S50. As described above, the furnace bottom plate 16 is inclined downward toward the outlet 16b at an angle θ smaller than the angle of repose of the flow medium 13. Therefore, as shown in FIG. 5, the flow medium 13 in the furnace body 12 is not completely extracted to the outside of the furnace in the extraction step S50, and a part of the flow medium 13 in the furnace body 12 is partially extracted on the furnace bottom plate 16 after the extraction step S50. The flow medium 13 of the above remains. More specifically, between the upper surface of the furnace bottom plate 16 and the U-shaped pipe portion 16a2 of the air diffuser pipe 16a, there is a region (immobile layer) that is not easily affected by the fluidized gas, and a certain amount of the immovable layer exists. The flow medium 13 remains. Hereinafter, the flow medium 13 remaining on the furnace bottom plate 16 after the extraction step S50 as described above is also referred to as “fire bottom medium (fire bottom sand)”.

The present inventors have newly discovered that valuable metals derived from waste (gold, silver, copper, lead, zinc, etc.) are contained in a high concentration in the bottom medium. That is, the bottom medium is a mixture of the flow medium 13 and the valuable metal. According to the findings of the present inventors, the furnace bottom medium has a significantly higher concentration of valuable metals than the flow medium 13 stored in the storage tank 44 in the extraction step S50, resulting in a bulk density (g / g /). cm ³ ) is also larger. Of the fluid medium 13 filled in the furnace body 12 before the extraction step S50, most (for example, 99%) is sent to the storage tank 44 in the extraction step S50, and the rest is on the furnace bottom plate 16. Remains as a bottom medium.

Therefore, in the recovery method according to the present embodiment, in the recovery step S60 following the extraction step S50, the flow medium 13 (flow medium stored in the storage tank 44) extracted from the furnace body 12 in the extraction step S50. Separately collect the bottom medium in a state separated from 13). Specifically, after the extraction step S50 is completed, an operator enters the furnace body 12 and collects the bottom medium to directly recover the bottom medium from the inside of the furnace body 12.

After that, the worker performs maintenance work such as cleaning and inspection of the inside of the furnace main body 12 (step S70). The inside of the furnace may be cleaned and inspected before the bottom medium is recovered, or the recovery of the bottom medium and the maintenance work inside the furnace may be performed in parallel.

As described above, in the recovery method according to the present embodiment, the fluidized medium 13 containing a high concentration of valuable metal derived from waste is recovered by utilizing the timing of maintenance of the fluidized bed gasifier 10. Table 1 below shows the storage tank 44 in the extraction step S50 in a plurality of waste treatment facilities (facilities A to E) having the same configuration as the fluidized bed gasifier 10 (FIG. 1) in the present embodiment. The results of investigating the valuable metal concentration (mg / kg) of the fluidized bed 13 recovered in the above and the valuable metal concentration (mg / kg) of the furnace bottom medium remaining on the furnace bottom plate 16 after the extraction step S50 are shown. ing. As is clear from Table 1, the concentration of valuable metals (Au, Ag, Cu) in the bottom medium is significantly higher than that in the flow medium 13 recovered in the storage tank 44. For facility A, two surveys were conducted at different times, and the results of each survey are shown in Table 1 in (1) and (2), respectively.

Table 2 below also facilities A, for B, the bulk density of the flowing medium 13 recovered in the storage tank 44 by an extraction step S50 (g / cm ^3), bulk density (g / ^cm 3) of the furnace bottom medium The result of the investigation is shown. As is clear from Table 2, the bulk density of the bottom medium is higher than that of the flow medium 13 recovered in the storage tank 44, which is considered to be due to the difference in the concentration of valuable metals.

Finally, the valuable metal is separated from the flow medium 13 (furnace bottom medium) recovered in the recovery step S60 (separation step S80). Specifically, the valuable metal contained in the furnace bottom medium is separated from the flow medium 13 by a method such as heat treatment, chemical treatment, or physical sorting. Examples of the heat treatment include melting treatment (smelting), firing treatment, chloride volatilization, and the like. Examples of the chemical treatment include solvent extraction of an acid or the like. Examples of the physical sorting include magnetic force sorting, eddy current sorting, electrostatic sorting, specific gravity sorting, and the like.

(Embodiment 2)
Next, a method for recovering the fluidized medium in the fluidized bed furnace according to the second embodiment of the present invention will be described mainly with reference to FIG. The method for recovering the fluidized medium in the fluidized bed furnace according to the second embodiment is basically the same as the method for recovering the fluidized medium in the fluidized bed furnace according to the first embodiment, but the specific method in the recovery step S60 is described above. It is different from Form 1. Hereinafter, only the differences from the first embodiment will be described.

FIG. 6 schematically shows the configuration of the fluidized bed type gasification melting furnace 1A in the second embodiment. In the fluidized bed gasification furnace 10A of the second embodiment, in addition to the configuration of the fluidized bed gasification furnace 10 (FIG. 1) of the first embodiment, the fluidized bed 13 is taken out of the circulation mechanism 40 and recovered. It further includes a mechanism 50.

As shown in FIG. 6, the recovery mechanism 50 includes a recovery path 51 connected to the first transport path 45, a first valve 52 provided on the recovery path 51, and a recovery path 51 on the first transport path 45. It has a second valve 53 provided on the downstream side of the connecting portion P1 of the above. The first valve 52 and the second valve 53 may be automatically controlled by a control unit (not shown) or may be manually controlled.

In the extraction step S50 in the second embodiment, the extraction screw 41 is rotationally driven with the first valve 52 closed and the second valve 53 open. As a result, the flow medium 13 extracted from the furnace body 12 to the outside of the furnace does not enter the recovery path 51, is transported upward by the circulation elevator 43, and then is supplied to the storage tank 44 in the same manner as in the first embodiment. Will be done.

Subsequently, in the recovery step S60 in the second embodiment, the first valve 52 is switched to the open state and the second valve 53 is switched to the closed state. Then, an operator enters the furnace main body 12 and drops the flow medium 13 remaining on the furnace bottom plate 16 from the outlet 16b into the extraction pipe 15. After that, the extraction screw 41 is rotationally driven.

As a result, the flow medium 13 remaining on the furnace bottom plate 16 after the extraction step S50 is discharged to the outside of the furnace body 12 and then is not transported to the storage tank 44 side, and is not transported to the storage tank 44 side (recovery). It is collected by route 51). As a result, similarly to the first embodiment, the bottom medium can be separately recovered in a state of being separated from the flow medium 13 stored in the storage tank 44 in the extraction step S50.

It should be understood that the embodiments disclosed as described above are exemplary in all respects and are not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

That is, the following modifications are also included in the scope of the present invention.

In the second embodiment, the case where the bottom medium is collected in the middle of the first transport path 45 has been described, but the collection port for the bottom medium is provided at another place (for example, the circulation elevator 43) in the circulation mechanism 40. May be done.

In the second embodiment, the case where the operator drops the bottom medium into the extraction pipe 15 has been described, but the bottom medium is dropped into the extraction pipe 15 by supplying the fluidized gas from the air diffuser pipe 16a. You may let me.

In the first and second embodiments, the fluidized bed gasifiers 10 and 10A for gasifying waste have been described as an example of the fluidized bed incinerator, but the fluidized bed incinerator for incinerating waste is also the present invention. A method for recovering a fluidized bed can be applied.

1,1A fluidized bed gasification and melting furnace 10,10A fluidized bed gasification furnace (fluidized bed furnace)
12 Furnace body 13 Flow medium 16 Furnace bottom plate 16b Extraction outlet 40 Circulation mechanism 43 Circulation elevator (conveyor)
44 Storage tank θ angle

Claims (3)

A furnace body, a flow medium filled in the furnace body, and an outlet for extracting the flow medium to the outside of the furnace body are formed, and at the same time, from the rest angle of the flow medium toward the outlet. In a flow bed furnace provided with a furnace bottom plate that inclines downward at a small angle and incinerates or gasifies waste containing valuable metals while the flow medium is flowing, the furnace is said to be stopped when the flow bed furnace is stopped. A method of recovering the fluid medium from the main body,
The extraction step of extracting the flow medium filled in the furnace body to the outside of the furnace body by gravity through the extraction port, and
A fluidized bed including a recovery step of recovering the fluidized medium remaining on the furnace bottom plate after the extraction step in a state of being separated from the flow medium extracted from the inside of the furnace body in the extraction step. A method for recovering a fluidized medium in a furnace. The method for recovering a fluidized medium in a fluidized bed furnace according to claim 1, further comprising a separation step of separating valuable metals from the fluidized medium recovered in the recovery step. The fluidized bed furnace is a circulation mechanism for returning the fluidized medium extracted to the outside of the furnace body to the furnace body, and is a transport unit for transporting the fluidized medium and the flow transported by the transport unit. Further comprising the circulation mechanism having a storage tank for storing a medium,
In the extraction step, the flow medium extracted to the outside of the furnace body is conveyed by the transport unit and supplied to the storage tank.
The fluidized bed in the fluidized bed furnace according to claim 1 or 2, wherein in the recovery step, the fluidized medium remaining on the bottom plate is discharged to the outside of the furnace body and then recovered at a place different from the storage tank. How to collect.

Images