JP2003093925A - Cyclone and circulating fluidized bed furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cyclone which keeps a critical particle diameter constant without making equipment large-sized and allows a control thereof as needed, and a circulating fluidized bed furnace using the same. SOLUTION: This circulating fluidized bed furnace is provided with a gate valve 40 which changes cross-sectional area of an inlet pipe 2a, the cross-sectional area of the inlet pipe 2a is changed as needed by the gate valve 40 and, therefore, the maintenance and control of flow rate of the gas which flows in from the inlet pipe 2a of the cyclone 2 to a main body part 2b are enabled without disposing any inserted material such as a parting cylinder in the main body part 2b of the cyclone 2.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cyclone for separating and recovering particles from a high temperature gas and a circulating fluidized bed furnace using the cyclone.

[0002]

2. Description of the Related Art Conventionally, a furnace body for burning an object to be treated such as sludge in a fluidized bed formed by fluidizing a fluid medium such as sand, and a fluid medium from a combustion gas discharged from the furnace body There is known a circulating fluidized bed furnace equipped with a cyclone for collecting particles such as.

This cyclone includes an introduction pipe for introducing a high-temperature gas containing particles, an outer cylinder vertically arranged with its upper end closed by a top plate, and tangentially introducing the gas from the introduction pipe, and a bottom of this outer cylinder. A conical cylinder which is coaxially connected to the and is tapered downward and an inner cylinder which penetrates the top plate from above the outer cylinder to form a gas outlet, and a bottom of the conical cylinder of the main body. And a particle discharge pipe connected to the. Then, this cyclone swirls the gas containing particles flowing into the main body from the introduction pipe in the main body to separate the particles and the gas by centrifugal force, while discharging the gas from which the particles have been removed from the inner cylinder. The particles are discharged from the particle discharge pipe.

In such a cyclone, the separation limit particle size δ, which is the smallest particle size that can be collected, is the cross-sectional area A of the introduction pipe, the flow velocity V of the combustion gas flowing into the main body by the introduction pipe, and the combustion gas It is known that the viscosity μ, the particle density ρ, the cyclone effective length H, and the ratio of the inner cylinder diameter D ₂ and the outer cylinder diameter D ₁ are determined by the following equation (1). There is. δ = [[(5.03μA) / (πρVH)] (D ₂ / D ₁ )] ^(1/2) …… (1)

Therefore, the cross-sectional area of the introduction pipe and the size of the main body in such a cyclone are set so that the separation limit particle diameter δ becomes a desired value based on the temperature and the flow rate of the combustion gas assumed in advance. Designed to.

[0006]

However, in the circulating fluidized bed furnace, there are differences in the properties of the object to be treated, such as sludge,
The flow rate and temperature of the combustion gas generated from the furnace body change greatly due to fluctuations in the load. Therefore, the gas flow velocity of the combustion gas flowing from the cyclone introduction pipe into the main body fluctuates significantly from the value assumed at the time of design, and the separation limit particle size δ
Was too large and particles of the fluid medium or the like were not sufficiently collected, and the separation limit particle diameter δ was too small, and conversely the pressure loss in the cyclone was too large. Therefore, there has been a demand to keep the separation limit particle size of the cyclone constant regardless of the gas flow rate and the like.

In addition, a fluidized medium such as sand tends to wear and become finer as it is used, becomes smaller than the separation limit particle size with the passage of operating time, and cannot be recovered by a cyclone, and is discharged out of the system. There is also a problem that the number of media increases and that the separation limit particle size of the cyclone does not reach a desired value when the fluid medium is changed to another type after completion of the cyclone. Therefore, there has been a demand to change the separation limit particle size of the cyclone as necessary.

In this regard, Japanese Patent Laid-Open No. 6-114291 discloses a partition cylinder between the inner cylinder and the outer cylinder, which form the main body of the cyclone, and which partitions the inner cylinder and the outer cylinder into an annular shape. At the same time, the gas introduced into the main body via the introduction pipe is distributed at the desired ratio inside (between the partition cylinder and the inner cylinder) and outside (between the partition cylinder and the outer cylinder) partitioned by this partition cylinder. There is disclosed a cyclone that has movable blades that can be provided near the entrance of the main body and that can freely adjust the particle collection capability with one cyclone.

However, in a cyclone of a circulating fluidized bed furnace for treating combustion gas containing particles such as fluidized medium at a high temperature from the furnace body, the inside of the cyclone in contact with the combustion gas is made of a refractory heat insulating material such as castable. Must be covered. Therefore, when installing a partition cylinder etc. with both sides covered with castable etc. inside the cyclone, it is necessary to upsize the device in order to sufficiently secure the effective space in the main body of the cyclone, and there are problems such as high cost. cause.

The present invention has been made in view of the above problems, and a cyclone capable of maintaining the separation limit particle diameter constant or adjusting it as necessary without increasing the size of the apparatus, and the same. An object of the present invention is to provide a circulating fluidized bed furnace using.

[0011]

A cyclone according to the present invention has an introduction pipe for introducing a high-temperature gas containing particles and a cylinder, and the gas from the introduction pipe is swirled in the cylinder to generate the particles from the gas. A cyclone having a refractory heat insulating member on its inner surface, and a cross-sectional area adjusting means for changing the cross-sectional area of the introduction pipe.

According to the cyclone of the present invention, it is possible to adjust the flow velocity of the gas flowing into the main body by changing the cross-sectional area of the introduction pipe. It is possible to control and maintain the separation limit particle size and the like in the main body of the cyclone without installing an insert.

Here, the cyclone of the present invention may include a gas flow velocity acquisition means for obtaining information on the gas flow velocity in the introduction pipe, and a control means for controlling the cross-sectional area adjusting means based on the information on the gas flow velocity. preferable.

The flow velocity of the high-temperature gas containing particles in the introduction pipe is acquired by the gas flow velocity acquisition device, and the control device controls the cross-sectional area adjusting device based on the change in the flow velocity of the gas. Since it is possible to maintain the flow velocity of the gas flowing into the chamber at a predetermined velocity, it is easy to make the separation limit particle diameter and the like in the main body of the cyclone constant regardless of the gas flow rate and the like. It is also easy to adjust the flow velocity of the gas flowing from the introduction pipe to the main body to a desired value in order to change the separation limit particle diameter.

In the circulating fluidized bed furnace of the present invention, the object to be treated is burned by the cyclone and the oxygen-containing gas in the fluidized fluidized medium, and the combustion gas containing the fluidized medium is introduced into the cyclone introduction pipe. A furnace main body for discharging, and a gas flow velocity acquisition means, an oxygen-containing gas flow rate acquisition means for acquiring information about the flow rate of the oxygen-containing gas introduced into the furnace main body,
An object-to-be-processed supply amount acquisition means for acquiring information about a supplied amount of the object to be processed introduced into the furnace body, and a combustion gas temperature acquisition means for acquiring information about a combustion gas temperature in the furnace body,
A pressure acquisition unit that measures information about the pressure in the furnace body, and a data processing unit that acquires information about the gas flow velocity in the cyclone introduction pipe based on the information are provided.

According to the circulating fluidized bed furnace of the present invention, the gas flow velocity in the cyclone introduction pipe is indirectly obtained based on relatively easily measurable information other than the gas flow velocity. It is possible to easily and reliably obtain the gas flow velocity of the combustion gas that is difficult to be measured directly including.
Therefore, it is possible to easily maintain or adjust the separation limit particle diameter and the like in the main body of the cyclone, and it is possible to efficiently collect particles such as the fluidized medium in the combustion gas from the furnace main body. Therefore, the circulating fluidized bed furnace can be operated properly.

[0017]

DETAILED DESCRIPTION OF THE INVENTION Referring to the accompanying drawings,
A preferred embodiment of a cyclone and a circulating fluidized bed furnace according to the present invention will be described in detail.

FIG. 1 is a schematic view showing a cyclone and a circulating fluidized bed furnace of this embodiment. The circulating fluidized bed furnace 100 of the present embodiment is a furnace for incinerating an object to be treated such as sludge,
A furnace body 1 that introduces and burns the object to be treated, a cyclone 2 that collects particles such as a fluid medium from combustion gas generated by combustion, and particles such as the fluid medium that are collected by the cyclone 2 into the furnace body 1. The loop seal 3 for returning is provided.

The furnace main body 1 includes a screw conveyor 14 for introducing the object to be processed supplied through the object line L1 into the furnace main body 1, and primary air (oxygen-containing gas) supplied through the primary air line L4. ) Is introduced into the furnace main body 1 to fluidize the fluidized medium and to primarily burn the object to be treated, and the primary air is introduced by introducing secondary air (oxygen-containing gas) supplied from the secondary air line L5. A secondary air nozzle 11 for secondary combustion of combustion gas, an extraction nozzle 15 for extracting incombustibles and the like from the bottom through a line L7, and a temperature raising fuel supplied through a temperature increase fuel line L3. A temperature raising burner 12 that burns fuel to raise the temperature of the fluidized medium and the like when the furnace body 1 is started up, and an auxiliary combustion burner 13 that burns auxiliary combustion fuel supplied through the auxiliary combustion fuel line L2 and auxiliary burns an object to be processed. , Equipped To have.

The furnace body 1 primarily burns an object to be treated in a high temperature fluidized bed 1a formed in the lower part by a fluid medium such as sand, and also primarily burns in a freeboard 1b above the fluidized bed 1a. The gas is further secondarily burned to complete combustion.

The fluidized medium forming the fluidized bed 1a is required to have a low specific gravity, a uniform fine particle size and a uniform particle size distribution so that it can be satisfactorily fluidized by primary air. In order to stir the object to be processed in 1a and to transfer the accumulated heat to the object to burn the object efficiently, it is required to have high melting point, inertness, and excellent thermal shock resistance and abrasion resistance. Further, silica sand or the like, especially river sand is generally used because it is required to be inexpensive and capable of stable supply in order to reduce running costs and the like.

The cyclone 2 is connected to an outlet at the upper part of the furnace body 1 and has a horizontal inlet pipe 2a for introducing a high temperature gas containing particles from the outlet, and a vertical pipe having an upper end closed by a top plate and an inlet pipe. An outer cylinder (cylinder) 2c for introducing the gas from 2a in a tangential direction, and a conical cylinder 2 which is coaxially connected under the outer cylinder 2c and is tapered downwardly.
d and a main body 2b having an inner cylinder 2e which penetrates the top plate from above the outer cylinder 2c and forms a gas outlet, and the main body 2
a particle discharge pipe 2f connected to the bottom of the conical cylinder 2d of b;
The gas containing particles flowing into the main body 2b from the introduction pipe 2a is swirled in the main body 2b to separate the particles and the gas by centrifugal force.

An exhaust gas line L6 for discharging the separated gas to the latter stage is connected to the inner cylinder 2e of the cyclone 2, and a loop seal 3 for returning the separated particles to the fluidized bed 1a is connected to the particle discharge pipe 2f. .

On the inner surface of the cyclone 2, there is provided a castable material 2g having fire resistance and heat insulation, which is a high temperature of about 850 ° C. or higher and contains particles such as a fluid medium in a high concentration. It is designed to withstand combustion gas.

In particular, the cyclone 2 of this embodiment is equipped with a gate valve (cross-sectional area adjusting means) 40 for changing the cross-sectional area of the introduction pipe 2a. This gate valve 40
Is a plate-shaped door 40a arranged at right angles to the gas flowing through the introduction pipe 2a, and a drive unit 4 for driving the door 40a up and down to adjust the cross-sectional area in the introduction pipe 2a.
And 0b.

The door 40a of the gate valve 40
As the above, one provided with a fireproof heat insulating member such as a castable member is preferable. Even if the door body 40a is provided with a castable member or the like, the above-mentioned JP-A-6-114291 is used.
Compared to installing castable members or the like on the movable blades in the main body of the cyclone described in Japanese Patent Publication, weight reduction is easier and driving from the outside is also easier.

The circulating fluidized bed furnace 100 also includes a gas flow velocity acquisition device 52 (gas flow velocity acquisition means) for acquiring the gas flow velocity in the introduction pipe 2a of the cyclone 2. The gas flow velocity acquisition device 52 includes a to-be-processed object supply amount measuring device (a to-be-processed object supply amount acquisition means) 20 for measuring a supplied amount of the to-be-processed object in the to-be-processed object line L1, and an auxiliary combustion fuel in an auxiliary combustion fuel line L2. The auxiliary combustion fuel flow rate measuring device 21 for measuring the flow rate of the fuel, the temperature rising fuel flow rate measuring device 22 for measuring the flow rate of the temperature raising fuel in the temperature rising fuel line L3, and the primary for measuring the flow rate of the primary air in the primary air line L4. An air flow rate measuring device 23, a secondary air flow rate measuring device 24 for measuring the flow rate of the secondary air in the secondary air line L5, and a temperature and pressure of the combustion gas installed in the furnace body 1 near the exit of the combustion gas. A temperature / pressure measuring device (pressure acquisition means, combustion gas temperature acquisition means) 25 for measurement,
Is equipped with. The primary air flow rate measurement device 23 and the secondary air flow rate measurement device 24 constitute an air flow rate measurement device (oxygen-containing gas flow rate acquisition means) 30 that measures the flow rate of the air supplied to the furnace body.

Further, the gas flow velocity acquisition device 52 is connected to each of these measuring devices 20 to 25, and based on the data measured by these measuring devices 20 to 25, the cyclone introduction pipe is expressed by the following equation (2). A data processing device (data processing means) 51 for determining the flow velocity S [m / hr] of the combustion gas flowing in 2a at 0 ° C. and 1 atmospheric pressure is provided. S = ((Q ₁ + Q ₂ + Q ₃ + Q ₄ + Q ₅ ) (273 + T ₁ ) P ₀ ) / (273P ₁ M) …… (2)

Here, Q ₁ [Nm ³ / Hr] is an excess air amount of the primary air, which is obtained by (primary air flow rate measured by the primary air flow rate measuring device 23−theoretical air flow rate), Q ₂ [Nm ³ / Hr] hr] is the excess air amount of the secondary air obtained by (secondary air flow rate measured by the secondary air flow rate measuring device 24-theoretical air amount), and Q ₃ [Nm ³ / Hr] is The amount of the combustion gas generated by the combustion of the supplied object to be treated, which is obtained by the supply amount measured by the measuring device 20 x the amount of the combustion gas per unit amount of the object to be treated, Q ₄ [Nm ³ / hr] is The auxiliary combustion burner 13 obtained by (the auxiliary combustion fuel flow rate measured by the auxiliary combustion fuel flow rate measurement device 21 x the combustion gas amount per unit fuel quantity)
The amount of combustion gas generated by the combustion of, Q ₅ [Nm ³ / hr] is calculated by (temperature-rising fuel flow rate measured by temperature-rising fuel flow rate measuring device 22 x combustion gas amount per unit fuel quantity), Amount of combustion gas generated by combustion of the hot burner 12, T
₁ [K] and P ₁ [Pa] are measured by the temperature and pressure measuring device 25, respectively, and the temperature and pressure of the combustion gas near the upper outlet of the furnace body, P ₀ [Pa] is 1 atm, that is, 101325 [Pa], M [m ² ]
Is a cross-sectional area of the introduction pipe 2a of the cyclone 2. And
The theoretical air amount used for the above calculation, the combustion gas amount per unit amount, and the like are preset in the storage means (not shown).

Here, the reason why the gas flow velocity in the introducing pipe 2a is indirectly obtained in this way will be described. Generally, the gas flow rate can be directly measured by a Pitot tube, an orifice, or the like. However, even if the combustion gas from the furnace body 1 containing particles such as a fluid medium at a temperature as high as 850 ° C. or higher is to be measured by these Pitot tubes or orifices, problems such as deformation, blockage, and wear due to the high temperature may occur. Occurs, and it is difficult to obtain reliable data. Therefore, as in the present embodiment, the flow velocity of the combustion gas in the introduction pipe 2a is indirectly obtained from a plurality of easily measured data, so that the flow velocity can be easily and reliably obtained.

The circulating fluidized bed furnace 100 further includes a control device (control means) 50 connected to the drive device 40b of the gate valve 40 and adjusting the opening degree of the gate valve 40. The control device 50 includes a gas flow velocity acquisition device 52.
Connected to the data processing device 51 of
Based on the gas flow velocity in the introduction pipe 2a acquired by the gate valve 40 so as to maintain the gas flow velocity flowing into the main body portion 2b of the cyclone 2 at a set predetermined value.
Is driven to adjust the opening cross-sectional area of the introduction tube 2a. Further, when the set value of the gas flow velocity set in the control device 50 is changed by an external input or the like, the gate valve 40 is similarly driven according to the change and the opening cross-sectional area is adjusted to flow into the main body 2b. It is possible to adjust the gas flow rate of the gas to a desired value.

Next, the operation of the cyclone 2 and the circulating fluidized bed furnace 100 according to this embodiment will be described.

First, a fluidized medium such as silica sand is charged into the furnace body 1 of the circulating fluidized bed furnace 100, and the temperature is increased by the temperature rising burner 12 to a predetermined temperature, and the primary air nozzle 10 is used.
The primary air is introduced through and fluidized. Next, the material to be treated is put into the furnace main body 1 through the screw conveyor 14 and is flowed in the fluidized bed 1a to be about 6 with primary air.
Primary combustion is performed at 50 ° C, secondary air is supplied to the primary combustion gas rising in the freeboard 1b through the secondary air nozzle 11, and secondary combustion is further performed at about 850 to 1000 ° C.

At this time, if necessary, the auxiliary combustion burner 13 heats the fluidized bed 1a so that the fluidized bed 1a can maintain a predetermined temperature.

The secondary combustion gas that has undergone secondary combustion is discharged from the outlet of the furnace body 1 through the introduction pipe 2a of the cyclone 2.
The cyclone 2 flows into the main body 2b of the cyclone 2 to be swung, and particles such as a fluidized medium are separated by a centrifugal force, extracted from the particle discharge pipe 2f, and returned to the furnace main body 1 via the loop seal 3.

On the other hand, the clean secondary combustion gas from which the particles have been separated and removed is discharged through the inner cylinder 2e and the exhaust gas line L6, and is detoxified and discharged by an exhaust gas treatment facility (not shown).

Here, if such operation is continued,
The temperature and amount of the combustion gas generated in the furnace body 1 fluctuate due to changes in the composition of the sludge or the like to be treated and differences in the input amount, and the gas of the combustion gas flowing from the introduction pipe 2a into the body portion 2b. The flow velocity may change significantly.

At this time, the control device 50 causes the data processing device 51 to obtain the introduction pipe 2a of the cyclone 2 based on the flow velocity data of the secondary combustion gas of the introduction pipe 2a of the cyclone 2, which is obtained based on the data of the measuring devices 20 to 25. Recognizing the change in the flow velocity of the secondary combustion gas of the Cyclone 2
The drive device 40b of the gate valve 40 is controlled so that the flow velocity of the gas flowing from the introduction pipe 2a into the main body portion 2b is maintained at a predetermined set value, and the cross-sectional area of the introduction pipe 2a is adjusted.

As a result, the flow velocity of the gas flowing from the introduction pipe 2a into the main body portion 2b is adjusted to a constant value, and the cyclone 2 does not have any inserts such as partition cylinders inside the main body portion 2b. It is possible to keep the separation limit particle diameter and the like in the second main body portion 2b constant. Therefore, even if the flow rate or the like fluctuates, scattering of the fluidized medium from the cyclone 2 and increase in pressure loss are suppressed.

In addition, when the sand, which is a fluid medium, is worn due to long-term operation and the particle size is reduced, if the set value of the gas flow velocity set in the controller 50 is increased, the controller 50 causes the gate valve to operate. 40 is driven to reduce the cross-sectional area of the introduction tube 2a. As a result, the flow velocity of the gas flowing from the introduction pipe 2a into the main body portion 2b is increased, and the separation limit particle diameter in the cyclone 2 is reduced, so that the fluidized medium having the reduced particle diameter can be collected by the cyclone 2. Made possible. Therefore, the frequency of replenishment of the fluidized medium is reduced, and the running cost and the like can be easily reduced.

Further, even when the type of flowing medium is changed, the set value of the gas flow velocity set in the control device 50 is changed to flow into the main body 2b from the introduction pipe 2a by the gate valve 40 in the same manner. The desired gas velocity can be set, and the separation limit particle size in the cyclone 2 can be easily adjusted.

Since the particles such as the fluidized medium in the combustion gas can be efficiently recovered in this way, the circulating fluidized bed furnace 100 can be operated properly.

The cyclone and the circulating fluidized bed furnace according to the present invention are not limited to the above embodiment, and various modifications can be made.

For example, in the above-described embodiment, the data processing device 51 uses the auxiliary combustion fuel flow rate measuring device 21 to supply the auxiliary combustion fuel supply amount data and the temperature rising fuel flow rate measuring device 22 to supply the temperature increasing fuel amount data. In consideration of the above, the flow velocity of the combustion gas in the introduction pipe 2a of the cyclone 2 is acquired. However, the present invention is not limited to this. If the amount is high and there is no need for auxiliary combustion, the gas flow rate may be acquired without acquiring these data.

In the above embodiment, the cyclone 2 employs the gate valve 40 which moves the door 40a in the vertical direction as the cross-sectional area adjusting means of the introduction pipe 2a. It is not limited to this as long as it can be reduced. For example, a gate valve in which the door body moves in the horizontal direction may be used, or a butterfly valve or the like may be used.

Further, in the above embodiment, the controller 50 controls the gate valve 4 in order to easily adjust the separation limit particle size.
Although the opening degree of 0 is adjusted, it is not limited to this.
When there is little fluctuation in the flow rate of the combustion gas and the like, it may be adjusted manually. However, since there is a danger of explosion in the furnace, it is necessary to take sufficient safety measures such as installing a safety valve.

[0047]

According to the present invention, the cross-sectional area adjusting means for changing the cross-sectional area of the introduction pipe of the cyclone is provided, and the cross-sectional area of the introduction pipe is changed by the cross-sectional area adjusting means,
It is possible to adjust the flow velocity of the gas flowing into the main body of the cyclone. This makes it possible to control and maintain the separation limit particle size in the cyclone body without installing any inserts such as partition cylinders in the cyclone body, and to collect particles without increasing the size of the device. The ability can be freely adjusted.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a cyclone and a circulating fluidized bed furnace of the present embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Furnace main body, 2 ... Cyclone, 2a ... Introducing pipe, 2b ... Main body part, 2c ... Cylinder, 2g ... Castable material (refractory heat insulating member), 20 ... Processing material supply amount measuring device (processing material supply amount acquisition means) ), 25 ... Temperature pressure measuring device (pressure measuring means,
Combustion gas temperature measuring means), 30 ... Air flow rate measuring device (oxygen-containing gas flow rate acquiring means), 40 ... Gate valve (cross-sectional area adjusting means), 50 ... Control device (control means), 51 ... Data processing device (data processing) Means), 52 ... Gas flow velocity measuring device (gas flow velocity acquisition means), 100 ... Circulating fluidized bed furnace.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F23G 5/30 ZAB F23G 5/50 E 5/50 K F27B 15/12 F27B 15/12 F23C 11/02 311 (72) Inventor Minoru Teshima 5-9-11 Kitashinagawa, Shinagawa-ku, Tokyo F-term within Sumitomo Heavy Industries Co., Ltd. (reference) 3K062 AA11 AB01 AC01 AC19 BA02 CB01 CB03 CB06 DA01 DA11 DA32 DB08 DB16 3K064 AA18 AB03 AD08 AE01 BA07 BA17 BB05 4D053 AA03 AB01 BA01 BB01 BC01 BD04 CA08 CB18 CG09 DA10 4K046 HA11 JE09

Claims (3)

[Claims] 1. An introduction pipe for introducing a high-temperature gas containing particles, and a main body having a cylinder for separating the particles from the gas by swirling the gas from the introduction pipe in the cylinder. A cyclone having a fireproof heat insulating member on its inner surface, comprising a cross-sectional area adjusting means for changing the cross-sectional area of the introduction pipe. 2. A gas flow velocity acquisition means for acquiring information about a gas flow velocity in the introduction pipe, and a control means for controlling the cross-sectional area adjusting means based on the information about the gas flow velocity. The cyclone according to claim 1. 3. A cyclone according to claim 2, and a furnace body for combusting an object to be treated with an oxygen-containing gas in a fluidized fluidized medium and discharging combustion gas containing the fluidized medium to an introduction pipe of the cyclone. , And the gas flow velocity acquisition means,
Oxygen-containing gas flow rate acquisition means for acquiring information regarding the flow rate of the oxygen-containing gas introduced into the furnace main body, and target object supply amount for acquiring information regarding the supply amount of the target object introduced into the furnace main body Acquisition means, combustion gas temperature acquisition means for acquiring information on combustion gas temperature in the furnace body, pressure acquisition means for measuring information on pressure in the furnace body, and introduction of the cyclone based on these information A circulating fluidized bed furnace, comprising: a data processing unit that acquires information about a gas flow velocity in the pipe.