JPH11263981A - Drying and classifying device for raw material coal for coke oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly safe drying and classifying device for a raw material coal using a fluidized bed capable of preventing the over-heating of the coal. SOLUTION: This drying and classifying device for a raw material coal for a coal over, equipped with a device main body 4 capable of forming a fluidized bed by blowing a gas up from a gas chambers 16a, b provided in the downward direction through a dispersing plate 5, and drying and classifying the raw material coal for a coke oven stored in a wet coal hopper 1 by the fluidized bed, is provided by connecting the fluidized bed for heating and drying the raw material coal by blowing a hot air with another fluidized bed for drying, and cooling the raw material coal by blowing a cool air through a partitioning wall 15 in a transporting direction of the coal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for drying and classifying raw coal provided with a fluidized bed for drying and classifying coal charged into a coke oven.

[0002]

2. Description of the Related Art Conventionally, dry classification of raw coal capable of forming a fluidized bed in order to dry raw coal charged into a coke oven and classify and remove fine powder in the raw coal. The device is being used.

For example, Japanese Patent Application Laid-Open No. 9-104871 discloses that a freeboard section in which a fluidized bed is formed and an air chamber for supplying gas to the freeboard section are divided into two or more sections. A dry classifier capable of adjusting the temperature of the gas supplied to the freeboard section is described, in which the temperature of the gas supplied to the freeboard section is set so as to increase gradually in the moving direction of the coal to improve thermal efficiency. Is planned.

[0004]

However, in the above-mentioned dry classification device, the gas temperature at the freeboard portion on the outlet side of the device may reach several hundred degrees, so that the coal is overheated and a part of it is burned. And there was a problem in terms of safety.

[0005] It is an object of the present invention to provide a dry classifier for raw coal using a fluidized bed, which is capable of preventing overheating of coal and having high safety. I do.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a coke oven raw coal drying and classification apparatus for drying and classifying a coke oven raw coal stored in a wet coal hopper by a fluidized bed. Wherein the fluidized bed for heating and drying the raw coal and the fluidized bed for cooling and drying the raw coal by blowing cold air are connected in the transfer direction of the raw coal through a partition wall. Achieved by

The drying classifier has an exhaust duct for discharging hot air after heating and drying and fine powder generated in the fluidized bed, and introduces hot air of a predetermined temperature generated by the hot air generator into the fluidized bed gas chamber. Along with forming a fluidized bed for heating and drying the raw coal by being ejected from the dispersion plate, a part of the hot air generated by the hot air generator is introduced into the exhaust duct via a bypass duct. Is preferred.

[0008] In the drying classifier, a dust collector for collecting fine powder is connected to an exhaust duct for discharging hot air after heating and drying the fluidized bed for heating and drying the raw coal and fine powder generated in the fluidized bed. It is preferable to provide a pipe for returning the heat-dried fine powder on the fluidized bed for cooling and drying the raw coal.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a schematic sectional view showing the overall configuration of a dry classification apparatus of the present invention, wherein 1 is a wet coal hopper for storing raw coal before dry classification, and 2 is a feeder for extracting a predetermined amount of raw coal. The cutting device 3 is a charging inlet, and the wet coal hopper 1
A predetermined amount of raw coal taken out from the cutting device 2 is charged into the device main body 4 through the charging port 3.

The apparatus main body 4 has a substantially box shape, and is provided with a dry coal discharge port 21 at an end opposite to the charging port 3, and a discharge apparatus for discharging a predetermined amount of coal after drying classification in the dry coal discharge port 21. 22
Is attached.

A dispersion plate 5 in the form of a flat plate is disposed in the apparatus main body 4 in the horizontal direction. Above the dispersion plate 5 is a fluidized bed forming chamber 6 in which a fluidized bed is formed. In the present embodiment, the fluidized bed forming chamber is divided into two by a partition wall 15, and the charging inlet 3 side is a fluidized bed forming chamber 6a for heating and drying, and the dry coal discharge port 21 is a fluidized bed forming chamber 6b for cooling and drying.

A large number of gas injection holes are formed in the dispersion plate 5 at a predetermined interval from each other, and pressurized gas in a gas chamber, which will be described later, is supplied above the dispersion plate 5 through the gas injection holes. Spout toward.

Fluidized bed forming chamber 6 for heating drying and cooling drying
Exhaust ducts 9a and 9b for discharging the fine coal particles together with the exhaust gas are provided on the ceiling of each of a and 6b. Cyclone dust collectors 14a, 14b are attached to the exhaust ducts 9a, 9b via pipes, respectively, so as to separate fine coal particles and exhaust gas. The separated pulverized coal particles are supplied to a pulverizing discharge device 17.
a and 17b are appropriately discharged.

In the present embodiment, a temperature sensor 11 is attached to a pipe connected to an exhaust duct 9a provided in a fluidized bed formation chamber 6a for heating and drying, and detects a temperature of exhaust gas in the pipe. ing.

Below the dispersion plate 5 is a gas chamber 16, which is divided into six in this embodiment. The three chambers on the charging port 3 side are heating gas chambers 16a for forming a fluidized bed for heating and drying, while the three chambers on the dry coal discharge port 21 side are cooling for forming a fluidized bed for cooling and drying. Gas chamber 16b.

Each heating gas chamber 16a has a hot air generator 1
From 3, a heating gas having a pressure sufficient to form a fluidized bed is introduced via a hot air duct 8. In the illustrated apparatus, a hot air flow control valve 7 is attached to each of the hot air ducts 8 connected to the heating gas chamber 16a, and the flow rate of the heating gas is set to an arbitrary value by the hot air flow control valve 7, and It can be adjusted independently for each heating gas chamber 16a.

Similarly, a cooling gas having a pressure sufficient to form a fluidized bed is introduced into the cooling gas chamber 16b from the blower 20 through the cool air duct 19. In the illustrated device, a flow control valve 18 is attached to each of the cool air ducts 19 connected to the cooling gas chamber 16b, and the flow rate of the cooling gas is set to an arbitrary value by the flow control valve 18 and each cooling gas is cooled. The adjustment can be made independently for each gas chamber 16b. Therefore, it is possible to finely control the ejection speed of the heating gas and the cooling gas ejected from the dispersion plate 5 corresponding to each location in the apparatus main body 4.

In the present embodiment, the hot air duct 8 branches off at the outlet side of the hot air generator 13, and the branch portion passes through the exhaust duct 9 a through the bypass duct 10 provided with the bypass flow rate control valve 12 at a predetermined position. It is connected to the. Therefore, a part of the heating gas from the hot air generator 13 can be introduced into the exhaust duct 9a, and the flow rate thereof can be adjusted by the bypass flow rate control valve 12.

Next, the operation of the dry classification device of the present invention will be described.

During operation of the drying classifier, the heating gas at about 400 ° C. from the hot air generator 13 is adjusted to a predetermined flow rate by the hot air flow control valve 7 and supplied into the heating gas chamber 16a. A part of the heating gas is also introduced into the exhaust duct 9a via the branched bypass duct 10. On the other hand, the cooling gas at room temperature is supplied from the blower 20 to the cooling gas chamber 24b via the cool air duct 19 while being adjusted to a predetermined flow rate by the flow rate control valve 18. Therefore, the heating gas and the cooling gas supplied to the heating gas chamber 24a and the cooling gas chamber 24b are distributed to the dispersion plate 5 respectively.
And jets out above the dispersion plate 5 through the gas injection holes.

On the other hand, undried and unclassified raw coal in the wet coal hopper 1 is supplied into the apparatus main body 4 through the charging port 3 by the cutout device 2 by a predetermined amount. Therefore, the raw coal is first agitated by the heating gas in the fluidized bed forming chamber 23a for heating and drying in the apparatus main body 4 to form a fluidized bed. Here, while the raw coal is dried by the heating gas, the fine coal particles are removed from the raw coal. Specifically, the fine coal particles in the raw coal are discharged from the exhaust duct 9a together with the exhaust gas, and the coarse coal particles move to the coarse coal particle discharge port 21 while being fluidized. In this way, the classification of the raw coal is performed.

When the exhaust gas is introduced from the exhaust duct 9a to the dust collector 14a and discharged to the outside, the moisture in the exhaust gas is reduced due to the temperature decrease of the exhaust gas.
a or condensed on the wall of the dust collector 14a, and a part of the dew may be mixed with the raw coal in the fluidized bed. In such a case, insufficient drying of the raw coal or corrosion of the dust collector may occur, but in the illustrated device,
The temperature of the exhaust gas is monitored by the temperature sensor 11, and the high-temperature heating gas supplied from the hot air generator 13 is controlled while controlling the bypass flow rate control valve 12 so that the temperature of the exhaust gas becomes a predetermined temperature or higher. Is introduced into the exhaust duct 9a via the bypass duct 10. Therefore, it is possible to prevent the occurrence of the dew condensation by maintaining the temperature of the exhaust gas high.

The coarse-grained coal dried by heating in the fluidized bed forming chamber 6a for heating and drying forms a fluidized bed while the dispersion plate 5
It moves upward to the discharge port side, and sequentially moves to the fluidized bed forming chamber 6b for cooling and drying. In the cooling-drying fluidized-bed forming chamber 6b as well, similarly to the heating-drying fluidized-bed forming chamber 6a, the raw coal is stirred by the cooling gas ejected from the dispersion plate 5 to form a fluidized bed. In the fluidized bed formation chamber 6b for cooling and drying, the cooling of the raw coal by the cooling gas, the additional drying and the additional removal of the fine coal particles from the raw coal are performed. Specifically, the residual fine coal particles in the raw coal that could not be removed in the heating and drying step are discharged from the exhaust duct 9b together with the exhaust gas, and the coarse coal particles move to the dry coal discharge port 21 while being fluidized. In this way, the classification of the raw coal is performed in an overlapping manner. The coal particles after classification are dried coal outlet 21
After that, a predetermined amount is taken out of the system by the discharging device 22.

As shown in FIG. 2, in order to improve the mixing of coarse coal in the fine coal, the fluidized bed forming chamber 6a for heating and drying is used.
In some embodiments, the dried and heated fine powder collected by the fine dust collector 14a through the exhaust duct 9a is recycled to the cooling / drying fluidized bed forming chamber 6b by the recovery pipe 23 via the discharge device 17a. In the fluidized bed formation chamber 6a for heating and drying,
Since the water content of the coal is large, the fluidity in the fluidized bed is poor, and it is necessary to supply a large amount of pressurized gas and increase the fluidizing gas velocity in order to secure the fluidity of the coal. For this reason, the ratio of the coarse coal mixed in the fine coal scattered with the hot air exhaust gas into the exhaust duct 9a increases. Therefore, by recycling the recovered fine coal into the fluidized bed forming chamber 6b for cooling and drying, the fine powder and the coarse coal are classified again in the fluidized bed, and the classification accuracy is improved.

[0026]

The present invention has the following effects.

(1) Since the fluidized bed is divided into two parts, and drying and classification with a heating gas are performed after the drying and classification with a cooling gas, overheating of the raw coal can be prevented, and the safety of operation is improved. Further, low-temperature dried coal can be obtained, and handling of the coal in the next step becomes easy.

(2) Since the fine powder is separated from the fluidized bed by the heating gas and the fine powder is also removed from the fluidized bed by the cooling gas, the separation efficiency of the fine coal adhering to the coarse coal particles is improved. Can be.

(3) By maintaining the temperature of the exhaust gas from the fluidized bed by the heated gas at a high temperature, it is possible to prevent dew condensation on the equipment wall, thereby preventing the adhesion of moisture to the raw coal or the corrosion of the equipment. can do. In addition, by using the same supply source of the heating gas for forming the fluidized bed and the heating gas for heating the exhaust gas, the drying device can be simplified.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing the entire configuration of a dry classification device of the present invention.

FIG. 2 is a schematic cross-sectional view showing the overall configuration of another embodiment of the dry classification device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Wet coal hopper 12 Bypass flow control valve 2 Extraction device 13 Hot air generator 3 Installation inlet 14 Dust collector 4 Device main body 15 Partition wall 5 Dispersion plate 16 Gas chamber 6 Fluidized bed forming room 17 Fine powder discharge device 7 Hot air flow control valve 18 Flow rate Control valve 8 Hot air duct 19 Cold air duct 9 Exhaust duct 20 Blower 10 Bypass duct 21 Dry coal outlet 11 Temperature sensor 22 Discharge device 23 Recovery pipe

Claims (3)

[Claims] 1. An apparatus main body for forming a fluidized bed by ejecting gas from a fluidized bed gas chamber provided below through a dispersion plate, wherein the raw coal for a coke oven stored in a wet coal hopper is fluidized bed. In a coke oven raw coal drying classifier that classifies by dryness, a fluidized bed that blasts hot air to heat and dry the raw coal, and a fluidized bed that blasts cold air to cool and dry the raw coal through a partition wall. An apparatus for drying and classifying raw coal for a coke oven, wherein the apparatus is connected to a raw coal transfer direction. 2. An exhaust duct for discharging hot air after heating and drying and fine powder generated in the fluidized bed is provided, and hot air at a predetermined temperature generated by a hot air generating device is introduced into the fluidized bed gas chamber to disperse the hot air. 2. A fluidized bed which is blown out from a plate to heat and dry the raw coal, and a part of hot air generated by the hot air generator is introduced into the exhaust duct through a bypass duct. Dry classification apparatus for raw coal for coke ovens according to 1. 3. A dust collector for collecting fine powder is connected to an exhaust duct for discharging hot air after heating and drying and fine powder generated in the fluidized bed in a fluidized bed for heating and drying the raw coal, and a dust collector for collecting the fine powder is provided. 2. The apparatus for drying and classifying raw coal for a coke oven according to claim 1, wherein a collection pipe for the fine coal is connected to a fluidized bed for cooling and drying the coal. 3.