JPH09104871A - Fluidized bed drying and screening machine and operating method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluidized bed drying and screening machine enabling an easy fluidization of particles on a dispersing plate, preventing an excessive drying and an excessive temperature elevation, and increasing a thermal efficiency at the same time, in drying and screening a raw material coal to be loaded in a coke oven in the fluidized bed. SOLUTION: This fluidized bed drying and screening machine is provided with a free board part 7 at the upper part and an air room 1 at the lower part, arranging a dispersing plate 2 between the free board part 7 and the air room 1, separating the free board part 7 and the air room into two or more rooms to enable transfer of the fluidized raw material coal for a coke oven in the transferring direction of the coal, installing a gas supplying duct 11 capable of controlling its flow rate to each of the air rooms 1 and also a gas discharging duct 12 capable of controlling its flow rate to each of the free board parts 7 for adjusting the flow rate and/or temperature of the gas in every room, passing through the dispersing plate 2 of each separated room. The partitioning plates 4 separating the free board part 7 are preferably installed as freely liftable so as to adjust the area of the opening part 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidized bed drying classifier used as a moisture drying and / or heating apparatus for raw coal for a coke oven, and a method of operating the same.

[0002]

2. Description of the Related Art The operation of reducing the dry distillation time in a coke oven by reducing the adhering water content of the raw material coal for the coke oven and charging it into the coking oven carbonization chamber has already been carried out.

As the moisture dryer, a drum dryer or a dryer for indirect drying and heating by passing superheated steam through a thin tube, charging coal on the outside and rotating the whole, and vice versa. Drying by passing coal in the tube and heating by passing superheated steam on the outside, or by blowing up coal particles with superheated gas in a drying preheating device with an air flow tower type to remove adhering water and preheating to a temperature of about 200 ° C. There are various dryers such as machines.

On the other hand, from the viewpoint of preventing dust generation during the transportation of dry coal or preheated coal, and suppressing the entrainment of pulverized coal (generally called carryover) in the gas generated when charging it into a coke oven, pulverized coal As a technique for classifying a portion and adding a binder or the like separately and charging it into a coke oven, it has already been disclosed in Japanese Patent Laid-Open No.
There are those described in JP-A-5-149382 and JP-A-55-48284.

A fluidized bed is disclosed in Japanese Patent Application Laid-Open No. 62-1 / 1987, in which one device has the two functions of water drying and classification.
It is disclosed in Japanese Patent No. 92486. The fluidized bed is a device that floats the entire particle layer while bubbling it and brings the gas and solid particles into contact with each other.The fluidized bed is fluidized according to the size relationship between the gas flow velocity and the terminal velocity for each particle size, and the small particle size part is scattered and classified. Since this device does not require separate equipment investment, equipment cost and space can be reduced.

Each function of moisture drying / heating / cooling and classification is
A fluidized bed is included in the base device. In the coke oven operation that requires energy saving and quality improvement technology in recent years, the cause is from the viewpoint of moisture drying of coal and the accompanying increase in dust generation during coal transportation and carryover suppression when charging into the coke oven. Classification of pulverized coal and prevention of dust generation of recovered pulverized coal are becoming important technical issues. Especially, it is considered to be the cause of carryover 2
For pulverized coal of 00 μm or less or fine particles of 80 μm or less, which is considered to be a cause of dust generation during coal transportation, a method of separating and collecting, adding a binder and kneading is effective.

The principle of the classification operation in the fluidized bed is that the entire particle bed is floated while bubbling to bring solid particles and gas into contact with each other to promote reduction of water content adhering to coal particles,
Pseudo-particles between particles are destroyed by the scrubbing effect between particles, and as shown in FIG. 3, the gas velocity at the freeboard part is the terminal velocity of the particles (also called terminal velocity or terminal relative velocity).
Only particles with diameters exceeding 4 will be scattered and classified. When the particle size is large, the terminal velocity is high and it is difficult to scatter, and when the particle size is small, the terminal velocity is small and the particles are easily scattered. The fine powder particles entrained in the gas in the freeboard section including the classification section are collected by a collection device such as a bag filter type dust collector provided in the subsequent step of the fluidized bed classifier. The terminal velocity u _t is given by the following equation 1.

[0008]

[Mathematical formula-see original document] u _t = √ (4dρ _m g / 3CDρ _g ) d: Particle diameter CD: Drag coefficient ρ _m : Particle density ρ _g : Gas density g: Gravitational acceleration

[0009]

When a fluidized bed drying classifier is also used for the purpose of classification, it is a difficult task to obtain a sharp classification efficiency with a target classified particle size as a boundary. Generally, the coarse particles are mixed in the classified fine powder at about 20%, and the fine coal is mixed in the coarse coal at about 10%.

In Japanese Unexamined Patent Publication (Kokai) No. 62-192486, it is assumed that the particle size of coal which causes dust is 70 μm or less, the particles are classified at 100 μm with a margin, and a binder is added to the classified pulverized coal for transfer. A method is disclosed in which a kneaded product is formed by motion or compression, and the kneaded product is mixed with coarse grain coal that does not generate dust and charged into a coke oven. However, there is no specific description about a method of performing efficient classification with a target of 100 μm as a boundary.

Further, Japanese Patent Laid-Open No. 6-343927 discloses a method of adjusting the gas flow velocity by adjusting the cross-sectional area of the fluidizing section as a method of improving the classification efficiency. However, the classification of particles is not determined only by the gas flow velocity in the fluidizing section, but is determined by the gas flow rate in the freeboard portion immediately above. The cross-sectional area of the suction blower side duct further above the freeboard section is reduced, and the gas flow velocity inside is at a level close to the terminal velocity of particles, and the factor controlling the particle classification point is the gas inside this classification section duct. It can be thought of as the flow velocity.

In addition, in the case where water drying and heating / cooling are sufficiently performed in an actual fluidized bed, the bed area should be increased or the material should be extended in the longitudinal direction so that the residence time of the particles in the fluidized bed can be long. Therefore, a horizontal fluidized bed that is long in a certain direction is formed, and therefore the water content and temperature of the particles in the vicinity of the inlet and in the vicinity of the outlet are greatly different. That is, in the moving direction of coal, there is a large amount of water near the inlet, the amount of pseudo particles of coal is large, and the diameter thereof is also large. Therefore, it is necessary to increase the gas flow rate required for bubbling. On the other hand, the water content of the coal near the outlet decreases, the pseudo particles collapse, and the gas flow rate required for fluidization decreases. Thus, since the optimum gas flow rate differs depending on the position of the dry classifier, it is necessary to adjust the gas flow rate suitable for classification depending on each part. Further, even if the amount of coal input changes, since the floor area is constant, the layer thickness may change, and fine adjustment may be required.

However, in the conventional fluidized bed, even if a plurality of supply gas ports from one or more air chambers are provided for the particle layer on the dispersion plate, the amount of gas discharged in the freeboard portion is It could not be controlled independently in each part of the moving direction of coal. That is, generally, one or two gas discharge ports are provided on the upper part of the freeboard part, but since the exhaust gas ducts are not separated by partitioning the freeboard part, the gas flow velocity cannot be adjusted, and as a result, It hindered the improvement of classification efficiency. Therefore, a technique is required to adjust the gas flow velocity in the freeboard section in each duct in the lengthwise direction of the fluidized bed.

On the other hand, when drying and heating are to be performed in the fluidized bed, hot gas is supplied from an air chamber provided below the dispersion plate under the fluidizing section, but the contact time between coal and gas is extremely short and the gas side Paying attention to, the heat is not sufficiently exchanged and discharged to the outside of the system. When drying and / or heating coal, a high temperature gas is used, but the gas rising from the fluidizing section to the freeboard section and discharged is still in a state of having high sensible heat. It is not preferable to discharge the hot exhaust gas as it is in terms of thermal efficiency, and a technique for blowing gas into the fluidized part particle layer corresponding to the dry state and temperature level of coal in the moving direction of particles in the fluidized bed is required.

The present invention solves these problems.

[0016]

A fluidized bed drying and classifying machine of the present invention has a freeboard section in an upper part and an air chamber in a lower section, and a dispersion plate is arranged between the freeboard section and the air chamber. In a fluidized bed dry classifier for coal, a freeboard portion and an air chamber are divided into two or more chambers in the moving direction of the coal so that the fluidized raw material coal for a coke oven can be moved, and a gas whose flow rate can be controlled is supplied to each air chamber. The fluidized bed drying classifier is characterized in that a duct is provided and a gas discharge duct whose flow rate is controllable is provided at each freeboard section. The partition plate that divides the freeboard portion is preferably provided so as to be movable up and down so that the opening area can be adjusted.

Further, the operating method of the fluidized bed drying classifier of the present invention is to supply gas to the raw material coal for the coke oven charged in the upper freeboard section from the lower air chamber through the dispersion plate,
In an operating method of a fluidized bed drying classifier for fluidizing and drying and raising the temperature of the raw material coal for a coke oven, a freeboard portion and an air chamber are provided in a moving direction of the coal so that the fluid raw material coal for the coke oven can be moved. A method for operating a fluidized bed drying classifier, characterized by dividing the chamber into more than one chamber and adjusting the flow rate and / or the temperature of the gas passing through the dispersion plate of each of the divided chambers for each chamber. It is preferable to measure the scattered particle size and / or the amount of dust in the gas discharge duct provided in each chamber of the freeboard section, and adjust the amount of gas sucked and discharged from each gas discharge duct based on the result.

The gas used in the present invention is air, an inert gas such as nitrogen or steam, or a combustion exhaust gas having a high sensible heat. When moisture is dried while raising the temperature of the coal, it is preferable to use high-temperature combustion exhaust gas.
When the coal is previously heated to about 100 ° C. by a dryer or the like, and the water content is dried while cooling the coal particles,
Alternatively, air can be used when raising the temperature of the coal below 100 ° C. However, when the coal is heated to 100 ° C. or higher, it is preferable to use an inert gas to prevent weathering of the coal, that is, deterioration due to air oxidation, and when the temperature exceeds 400 ° C. or at low temperature. Even if there is a high coal dust concentration, it is advisable to use an inert gas in order to prevent explosion due to spontaneous ignition or the arrival of an ignition source such as a spark.

Further, in the apparatus in which the freeboard portion and the classification chamber are independently provided, the classification chamber is obtained by deforming the cross-sectional area and / or the height of a part of the freeboard portion, and thus the freeboard according to the present invention. The board section shall include a classification room.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a fluidized bed drying classifier and its operating method of the present invention will be described in detail with reference to the drawings.

According to the present invention, as shown in FIG. 1, the freeboard section 7 and the air chamber 1 are divided into two or more chambers in the moving direction of coal, and the particles move from the fluidizing section to the freeboard section 7. The opening 13 is left so as not to interfere with the above.
That is, the gas introduced into a certain air chamber 1 passes through the corresponding dispersion plate 2 to fluidize the particles, and the gas is discharged through the corresponding chamber of the freeboard section 7.

What is important here is that the length of the partition plate 4 of the freeboard portion 7 is changed from the top plate of the freeboard portion 7 to the particle layer 3
It is to reach the level within. If the gap between the particle layer 3 and the partition plate 4 is large, the gas flowability between the chambers in the freeboard portion 7 is increased, and the partition effect is reduced. On the contrary, if the depth of insertion into the particle layer 3 is large, the mobility of the fluidized particles is hindered. Therefore, when the thickness of the particle layer 3 is about 500 mm, it is preferable that the partition plate 4 has a length from the ceiling of the freeboard portion 7 to a level 500 mm above the dispersion plate 2.

As described above, the amount of gas injected into the fluidized bed can be adjusted independently in the moving direction of coal, that is, in the longitudinal direction of the fluidizing section. That is, in the chamber near the outlet, an appropriate gas flow rate can be given for classification, and in the chamber near the inlet, the gas flow rate is particularly increased in order to control the water drying rate or to fluidize the water with a high content. It becomes possible to form an appropriate gas flow velocity in the longitudinal direction of the fluidized bed in response to any needs.

The partition plate 4 of the freeboard section 7 is actually easy to set the opening 13 in the operating state in advance at the time of construction of the facility, but when a large change in the operating state is expected. It is effective to provide the partition plate 4 so that it can be moved up and down so that the area of the opening 13 can be adjusted according to the operating condition. That is, in general, the bed thickness in the fluidized bed dryer is around 500 mm, but when the processing amount is reduced and the residence time in the fluidizing section is sufficient, the pressure loss of the gas inlet fan is reduced. It is possible to adopt a small condition, that is, an operating condition in which the particle layer thickness is made thin. In such a case, if the partition plate 4 of the freeboard portion 7 is higher than the fluidized particle layer 3 and the distance between the lower end of the partition plate 4 and the layer surface is wide, the chambers of the freeboard portion 7 will be Independence of gas flow is lost. Therefore, by making the partition plate 4 a slide sleeve type and changing the length of the shielding part up and down, it is possible to follow the change in the thickness of the particle layer 3.

When particles such as coal are intended to be dried, preheated or cooled by using the fluidized bed, the partition between the air chamber and the freeboard section is very effective. Specifically, the properties of the gas charged into each chamber can be easily changed.

For example, when the raw coal for a coke oven having a water content of 10% is dried and preheated to 2% in the fluidized bed, when the temperature is rapidly raised, the water in the intragranular crack portion is rapidly expanded or evaporated. , Grain refinement occurs. For example, if a high temperature gas of 600 ° C is applied to coal near the inlet, particles will be several 100 ° C /
It is heated rapidly for more than a minute and finely pulverized to reduce the average particle size. This causes carryover when charged into the coke oven and also causes a decrease in the bulk density of the charge. Further, the exhaust gas becomes a uniform gas having a temperature of 300 ° C.

Therefore, for example, the fluidized bed dryer is divided into three parts in the moving direction of coal, and is dried at a gas temperature of about 100 ° C. in the initial stage in the fluidized bed, that is, in the chamber near the inlet, and the charged gas temperature in the second chamber. Up to about 300 ° C and 550 in the third room
The gas temperature is set to ℃, and in the chamber at the outlet, the gas flow rate in the classifying unit is calculated according to the target particle size of the classifying particles, and the gas amount is set so as to match the flow rate. By doing this, the heating rate of the coal is relaxed and grain refining is suppressed, and the exhaust gas temperatures are 50 ° C, 230 ° C and 400 ° C, respectively.
As compared with the case of uniform discharge at 300 ° C, a gas with a higher temperature level can be recovered and can be effectively used for other purposes, and a gas with a low temperature level and a high moisture content can be removed from the system via a dust collector. It is possible to realize an optimum process flow that considers the heat level such as discharging, and as a result, the thermal efficiency is also improved.

On the contrary, when cooling the coal particles discharged from the heater at about 100 ° C., the amount of gas supplied to each divided chamber and the flow velocity in the duct discharged from each freeboard unit are adjusted. It is effective to do. In the case of high-temperature coal without adhering water, gas is highly scattered, and the gas flow velocity in the fluidization part can be increased correspondingly to the thick layer near the inlet, and can be reduced in the latter stage.

In order to improve the classification property, it is effective to adjust the classification flow velocity accurately by increasing the opening area of the gas discharge duct near the inlet and decreasing the opening area of the duct near the outlet. Therefore, an exhaust gas velocity meter is installed in the middle of each duct, and the damper is adjusted so that the target flow velocity is achieved.

[0030]

EXAMPLES Examples of the present invention will be described in detail below.

[0031]

[Example 1] Conventionally, the raw material coal for a coke oven was 260 t / h
First, the indirect heating method was used to reduce the water content to 5% before charging it into the coke oven. By further reducing this water content by about 1%, we aimed to enjoy the effects of dry distillation heat quantity and coke quality improvement.

Since it was feared that dust and carryover would increase during transportation by reducing the water content, it was decided to separate the pulverized coal which is the cause before transportation as a countermeasure as a countermeasure. Therefore, we decided to use a fluidized bed classifier, but it is important to improve the classification efficiency and reduce the amount of coarse coal mixed in the classified pulverized coal and the amount of pulverized coal mixed in the coarse coal. However, it was to prevent dust generation during transportation.

Using a horizontal fluidized bed which does not divide the conventional freeboard part, a gas amount which gives a gas flow velocity for fluidizing 5% moisture coke oven raw material coal is supplied to the entire surface of the dispersion plate through an air chamber. Blow on average. As the gas, ambient air at ambient temperature was taken in and used. Aiming at classification with 0.3 mm of coal particles, it was blown in so that the flow velocity of the classification section would be 1.6 m / sec.

However, in the region near the inlet of the fluidized bed, the transportability does not improve, and the layer thickness of the fluidized part particle layer becomes non-uniform,
The variation in water content of the particles was as high as ± 0.7%, and the average water content value was 4.6%, which was a high level compared to the target value of 4.0%.

Therefore, according to the present invention, as shown in FIG. 1, the air chamber 1 and the freeboard portion 7 are divided into four parts in the moving direction of the raw material coal for the coke oven, and the gas flow path is divided into parts. The lower end position of the partition plate 4 was adjusted to a level in contact with the upper surface of the fluidized portion coal particle layer, so that the flow and movement of coal were not obstructed. When the treatment amount decreased and the layer thickness decreased, the lower end of the partition plate 4 was also adjusted to be lowered. This is because no gap is created in the upper portion of the particle layer 3 between the chambers of the freeboard portion.

As shown in FIG. 2, the partition plate 4 is composed of an outer plate and an inner plate suspended from a top plate of a freeboard portion 7 having a height of 3 m.
The partition plate 4 is divided into two parts. The outer plate has a length of 2 m, and the inner plate stored inside the outer plate can slide up to 1 m to extend the partition plate 4 downward. A pinion was provided outside the fluidized bed side wall, a rack was attached to the side surface of the partition plate 3, and the inner plate was lowered by manually turning the pinion.

Similarly, ambient air was used as the gas and was supplied to each partitioned air chamber. The gas was discharged through a gas discharge duct 12 installed from each of the divided chambers of the freeboard section 7. The exhaust gas flow velocity in the gas exhaust duct 12 was set as shown in FIG. 4 to have a pattern that promotes fluidization in the first and second chambers.

The cross-sectional area of the freeboard section of the first and second chambers is
The structure is such that it spreads on the dispersion plate at a height of 1 m or more and only small particles of 0.1 mm or less are scattered. Since the water content of coal in the fourth chamber was almost reduced, the gas flow velocity in the fluidization section was reduced to 2 m / sec, and the gas flow rate in the freeboard unit was adjusted to 1.6 m / sec.

The pulverized coal entrained in the gas discharged from the freeboard section is guided to a filter cloth type dust collector, the gas is released from the stack after being collected, and the pulverized coal is recovered and a binder is added. The mixture was uniformly kneaded with a twin-screw mixer, conveyed, and charged into a coke oven.

As a result, the flow of coal becomes smooth,
There is no part that stays or the layer thickness becomes thin, the amount of kneaded pulverized coal in the discharged coarse-grained coal decreases, and at the same time, the water content of coal is 4% ±
Stable to about 0.2%.

[0041]

[Example 2] Treatment amount 2 for raw material coal for coke oven
It was decided that 60 t / h was first reduced to 2% water by the indirect heating method, the temperature was heated to 90 ° C., and then the fluidized bed was used to heat the water to 0% and the coal temperature to 250 ° C.

When heated using a conventional fluidized bed, about 20
A gas of 530 ° C. of 0,000 m ³ / h is blown in, and the exhaust gas is discharged as a dust-containing gas of 400 ° C. Since a high temperature gas is used, a high heat resistant material such as YUS is used as the material for the classification member, which increases the equipment cost. In addition, the sensible heat of the exhaust gas temperature is large, and the efficiency is low in terms of heat consumption. Furthermore, because the gas flow velocity in each part of the freeboard longitudinal direction cannot be controlled, the heating state of coal with variations in particle size may fluctuate to about ± 50 ° C, resulting in overheating of pulverized coal. Therefore, it is not possible to use a heating method that is effective in controlling the temperature according to the state of coal.

Therefore, according to the present invention, the freeboard portion is partitioned in the moving direction of the raw material coal for the coke oven, the length is evenly divided into five chambers, and the supply gas amount control function and the exhaust amount control function are provided for each chamber. And to heat. The air chamber was also divided corresponding to the freeboard section, and the temperature and amount of gas supplied to each chamber were adjusted. As shown in Fig. 5, the gas temperatures are 150 ° C, 200 ° C, in order from the chamber near the coal inlet.
It was set to 250 ° C., 350 ° C., 500 ° C., and the gas amount was set to 2 to 3 m / sec in terms of the gas flow rate in the freeboard section. 0.1m / sec each time, 1.4 in the final room
Heating and classification were performed at m / sec.

As a result, the coarse coal is not mixed into the pulverized coal side of 0.1 mm, and the amount of the pulverized coal of 0.1 mm is extremely small on the coarse coal side. There was little carryover during charging and sufficient classification efficiency was obtained. Particularly, pulverized coal was not overheated and could be heated without impairing the caking property. Although there was a particle size distribution in the coal, the pulverized coal portion could be heated to the target temperature of 250 ° C within ± 20 ° C without overheating.

Further, as a means for improving the thermal efficiency, the high temperature exhaust gas of 370 ° C. from the final chamber is supplied to the third chamber two stages before, and further the exhaust gas of 150 ° C. of this third chamber is supplied to the first chamber. As a result, the heat of the exhaust gas can be effectively used, and the thermal efficiency as a whole can be improved. In this case, install a dust collector that collects and collects the classified pulverized coal on the way from the outlet side of each discharge duct to the inlet of the next air chamber, and remove dust to reuse it, which may lead to equipment trouble or It was possible to avoid clogging of the gas blowing nozzle.

[0046]

[Example 3] Conventionally, raw material coal for coke oven 260 t / h
First, the indirect heating method was used to reduce the water content to 5%, but by contacting it with room temperature air, the sensible heat of the coal was converted to heat of vaporization, with the aim of further reducing this water content by about 1%. It was

Since it was feared that dust and carryover would increase during transportation by reducing the water content, as a countermeasure, pulverized coal of 0.1 mm or less, which is the cause, should be separated before transportation. I chose Therefore, we decided to use a fluidized bed classifier, but it is important to improve the classification efficiency and reduce the amount of coarse coal mixed in the classified pulverized coal and the amount of pulverized coal mixed in the coarse coal. However, it was to prevent dust generation during transportation.

Therefore, as in the first embodiment, as shown in FIG. 1, the space from the top of the air chamber 1 and the freeboard portion 7 to the vicinity of the surface of the particle layer is divided into four chambers in the moving direction of the raw material coal for the coke oven. The exhaust pipe from each of the divided chambers was provided with a gas discharge amount adjusting damper 9 so that the exhaust flow rate could be adjusted. This is aimed at adjusting the particle size of the pulverized coal particles, which flow out together with the gas, although the gas flow velocity required for fluidization changes depending on the coal state in each chamber, especially the adhering moisture. In order to avoid over-drying and over-heating of pulverized coal particles, it is better to scatter fine particles of less than 0.1 mm after drying, and conversely, to avoid scattering of coarse particles that are not preferable due to insufficient drying. The flow velocity of each duct was measured and controlled according to the target particle size classification for each chamber.

As shown in FIG. 6, the flow velocity in the duct was measured using a Pitot tube type current meter 14, and the first chamber had a flow velocity of 1.0 m / m.
The second chamber was adjusted to 1.2 m / sec, the third chamber was adjusted to 1.4 m / sec, and the fourth chamber was adjusted to 1.6 m / sec. As the gas, ambient air was used.

As a result, it was possible to improve the classification efficiency of coal, such as the inclusion of coarse-grained coal, the inclusion of insufficiently dried coal, and the reduction of overheated coal in the classified fine coal powder.

[0051]

EFFECTS OF THE INVENTION According to the present invention, it becomes possible to form a fluidized state suitable for each part even when drying proceeds in the fluidized bed, and while keeping the kneading effect by the flow in each chamber high, It is possible to maintain the moving conveyance and sharply classify by the target classifying particle size in the final stage. In addition, since gas with different temperatures can be supplied to each of the divided chambers, when drying the water adhered to the coal particles, mild dry heating can be realized without changing the coal properties, and cracking and reduction of caking are suppressed. be able to. Further, in the case of high temperature heating, the exhaust gas can be recycled and the overall thermal efficiency can be increased. Also, in order to obtain sharp classification, the flow velocity in the gas discharge duct from each chamber is adjusted by a damper installed in the duct, and pulverized coal with a certain particle size from ducts other than the last stage is entrained in the gas. Since they can be separated and discharged, it is possible to prevent dust generation during the transportation of coarse coal.

[Brief description of the drawings]

FIG. 1 is a sectional view of a fluidized bed drying classifier of the present invention.

FIG. 2 is a diagram showing an example of a freeboard partition plate.

FIG. 3 is a diagram showing an example of a relationship between a freeboard portion gas flow velocity and a classified particle diameter.

FIG. 4 is a diagram showing an example of an exhaust gas flow velocity pattern in each chamber of a divided freeboard unit.

FIG. 5 is a diagram showing an example of a gas temperature pattern supplied to each air chamber.

FIG. 6 is a diagram showing an example of an apparatus for measuring a gas flow velocity in a gas exhaust duct.

[Explanation of symbols]

 1 Air Chamber 2 Dispersion Plate 3 Particle Layer 4 Partition Plate 5 Coal Inlet 6 Coarse Coal Outlet 7 Freeboard Part 8 Classification Room 9 Gas Emission Adjustment Damper 10 Partition Plate 11 Gas Supply Duct 12 Gas Exhaust Duct 13 Opening 14 Pitot tube anemometer

Claims (4)

[Claims] 1. A fluidized bed dry classifier for a raw material coal for a coke oven, which has a freeboard portion in the upper portion and an air chamber in the lower portion, and a dispersion plate is arranged between the freeboard portion and the air chamber. The freeboard part and the air chamber are divided into two or more chambers in the moving direction of the coal so that the raw material coal can move, and a gas supply duct that can control the flow rate is provided in each air chamber, and the flow rate can be controlled in each freeboard part. A fluidized bed dryer and classifier equipped with a gas discharge duct. 2. The fluidized bed drying classifier according to claim 1, wherein a partition plate for dividing the freeboard section is provided so as to be able to move up and down so that the opening area can be adjusted. 3. A flow in which gas is supplied from a lower air chamber to a raw material coal for a coke oven charged through an upper freeboard section through a dispersion plate to cause the raw material coal for a coke oven to flow to dry and raise the temperature. In the operation method of the bed dryer / classifier, the freeboard portion and the air chamber are divided into two or more chambers in the moving direction of the coal so that the fluidized raw material coal for the coke oven can be moved, and the dispersion board in each of the divided chambers is passed. A method for operating a fluidized bed drying classifier, characterized in that the flow rate and / or temperature of gas is adjusted for each chamber. 4. The method for operating a fluidized bed dry classifier according to claim 3, wherein the scattered particle size and / or dust amount in the gas discharge duct provided in each chamber of the freeboard section is measured, and based on the result. The method of operating a fluidized bed drying classifier is characterized in that the amount of gas sucked and discharged from each gas discharge duct is adjusted.