JPH1183319A - Device for drying and classifying coal using fluidized bed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further improve the drying and classifying efficiency in a coal drying and classifying device, in which coal is transferred for drying and classification while it is fluidized by a fluidized bed formed on a dispersion plate. SOLUTION: In a coal drying and classifying device using a fluidized bed, baffle plates 21... are erected above a dispersion plate 12, their lower end 21A is set to the height H in the range of 200 to 450 mm from the dispersion plate 12, and the height L of the baffle plates 21 from the lower end 21A to the upper end 21B is in the range of 300 to 1000 mm. A plurality of stages of straightening plates 23... are provided above a fluidized bed 13, adjacent straightening plates 23... in the vertical direction are inclined in the reverse direction to each other relative to the dispersion plate 12 in the side section along the transfer direction F, and deviated in the transfer direction F.

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 coal using a fluidized bed for classifying and removing fine powder in coal while drying coal supplied to a coke oven or the like. .

[0002]

2. Description of the Related Art As such a coal dry classification apparatus,
The inventor of the present invention disclosed in Japanese Patent Application Laid-Open No. Hei 5-71875 a nozzle 2 provided on a dispersion plate 1 as shown in FIG.
A drying classifier having a fluidized bed 3 in which the direction of jetting of gas G jetting from... Is set obliquely upward with respect to the dispersion plate 1 toward the transport direction F of coal C is proposed. Here, the transfer direction F of the apparatus main body 4 of the drying classifier is described.
A supply section 5 for coal C is provided at one end on the rear side, and a discharge section 6 for dried coal C is provided at the other end on the transfer direction F side. Also, under the dispersion plate 1,
A pressurized chamber 7 for gas ejected from the nozzles 2 to the fluidized bed 3 is provided. In the pressurized chamber 7, for example, hot air is supplied as a flowing gas G. Further, an exhaust port 9 for discharging the exhaust gas G from the fluidized bed 3 and the classified fine powder D is provided at the center of the ceiling portion 8 of the apparatus main body 4.

However, according to such a coal dry classification apparatus using the fluidized bed 3, the fluidized bed 3 is supplied from the supply unit 5.
Among the coal C supplied to the coal, coarse coal particles of the particle size,
The jet gas G spouted from the nozzles 2 is dried while rolling on the bottom of the fluidized bed 3 in the vicinity of the dispersion plate 1, while the coal particles having a relatively small particle size have an appropriate flow acceleration due to the jet gas G. Is dried while being fluidized, transferred in the transfer direction F, and discharged from the discharge unit 6. Furthermore, the fine powder D having a smaller particle size than these is classified by the jetting gas G from other particles and is discharged from the exhaust port 9 together with the exhaust gas G. Therefore, according to the dry classification device, efficient coal Drying of C and classification and removal of fine powder D can be achieved.

[0004]

However, the raw coal C subjected to the dry classification by such an apparatus has an average particle size of about 0.8 mm to 2.0 mm, but has a maximum particle size of 50 mm. Coarse particles of ~ 100mm to minimum particle size of 10
The width of the particle size distribution including the fine powder D of 5 μm or less is large, and the particle size distribution and the water content are not constant, and vary greatly depending on the place of production and the state of transportation. For this reason,
For example, when the raw coal C having a high content of the fine powder D and a relatively low water content is supplied to the fluidized bed 3, the heavy fine powder D containing water is not discharged from the exhaust port 9 but is supplied from the supply unit 5. There is a possibility that a large amount of the short-pass passes to the discharge unit 6 and is discharged together with the coal particles as it is, thus impairing the dry classification efficiency. In this regard, in a conventional general fluidized bed, in order to prevent such a short path, various types in which a baffle plate (baffle plate) is provided on a dispersion plate have been proposed. Simply applying the above to the dry classification of coal having a large particle size distribution as described above causes a problem that coal particles having a large particle size stay and are not transferred, and the operation becomes impossible.

On the other hand, in such a fluidized bed, the superficial velocity in the freeboard portion above the fluidized bed may vary. In particular, in the dry classifier having the above configuration, the jet direction of the gas G ejected from the nozzles 2 of the dispersion plate 1 is
As described above, since the gas C is inclined obliquely upward with respect to the dispersion plate 1 in the transport direction F of the coal C, the flow of the gas G tends to be deviated and the superficial velocity tends to vary widely. For example, the minimum superficial velocity is 0.5 of the average superficial superficial velocity.
In some cases, the maximum superficial velocity may be about 2.0 times the average superficial velocity. When the superficial velocity in the upper part of the fluidized bed 3 becomes large in this way, and particularly when the maximum superficial velocity partially increases, the coal particles having a relatively large particle diameter are exhausted in the exhaust port, contrary to the above case. Exhaust G from 9
In addition, the powder is mixed with the fine powder D and discharged, so that the classification efficiency is also impaired. For this reason, in the above-mentioned conventional dry classifier, in order to solve such a problem, the height from the dispersing plate 1 to the ceiling 8 must be at least 6.5 m or more, and the size of the equipment is increased. Was the result.

The present invention has been made under such a background, and uses a fluidized bed formed by a gas ejected from a dispersing plate to transport and dry-classify coal while fluidizing the coal. First, while preventing coarse coal particles in the coal supplied to the fluidized bed from staying, the fine powder is prevented from short-passing. Dry classification that suppresses variations in the superficial velocity in the board section, prevents even large-sized coal particles from being discharged from the exhaust port, and further improves the dry classification efficiency of coal. It is intended to provide a device.

[0007]

Here, the inventors of the present invention provide a baffle plate above a dispersion plate in a fluidized bed to which coal is supplied, and a height between the baffle plate and the dispersion plate. When the height of the baffle plate itself was changed variously, when these heights were within a predetermined range, even if the particle size distribution and water content of the coal supplied to the fluidized bed varied, the coarse coal It has been found that while particles can be reliably transferred, a short path of fine powder can be surely prevented. The invention according to claim 1 of the present application achieves the first object based on such knowledge, and transports coal while flowing it by a fluidized bed formed by gas ejected from a dispersion plate. In a coal dry classification apparatus using a fluidized bed for dry classification, a baffle plate is erected above the dispersion plate so as to cross the coal transfer direction, and the lower end of the baffle plate is connected to the dispersion plate. From 200 mm to 450 mm, and the height from the lower end to the upper end is 300 mm to 10 mm.
It is characterized in that it is in the range of 00 mm.

Therefore, according to such a coal classification apparatus, the coarse particles of the coal supplied to the fluidized bed are dispersed by the gas ejected from the dispersion plate and the baffle erected above the dispersion plate. The baffle plate blocks the flow of fines in the coal from its supply to the discharge while drying while being transported between the plates.
Then, since the height of the lower end of the baffle plate from the dispersion plate and the height of the baffle plate itself are set in a predetermined range based on the above knowledge, even if the particle size distribution and the like of the raw coal fluctuates. In addition, coarse coal particles can be reliably transferred, and a short path of fine powder can be prevented. That is, if the height of the lower end of the baffle plate from the dispersion plate is less than 200 mm, coarse coal particles may be clogged and smooth transportation may be impeded, while the height of the lower end of the baffle plate may be reduced. If the height exceeds 450 mm or if the height of the baffle plate itself is less than 300 mm, there is a risk that the fine powder short-passes on the gas flow from above and below the baffle plate. Further, if the height of the baffle plate itself exceeds 1000 mm, the height of the equipment and equipment is increased accordingly, which is uneconomical. In addition, especially when the water content of the raw coal is high, the fine powder is removed from the upper end of the baffle plate. There is a possibility that it will adhere to the surface.

On the other hand, in order to achieve the second object, the invention according to claim 2 of the present application provides a fluidized bed formed by gas ejected from a dispersing plate to transport coal while flowing it and dry classify it. In a coal dry classification device using a fluidized bed, in the upper part of the fluidized bed, a plurality of straightening plates extending in a direction crossing the coal transfer direction, a plurality of straightening plates in the transfer direction, and a plurality of stages in the vertical direction. Provided, the rectifying plates of these vertically adjacent stages are inclined in opposite directions to the dispersing plate in a side cross section along the transport direction, and are arranged so as to be shifted in the transport direction. I do. Therefore, the gas flow in the freeboard section is made uniform while rising between the straightening plates, thereby suppressing variations in superficial velocity, and in particular, since the maximum superficial velocity is suppressed, so Also, it is possible to prevent coal particles having a large particle diameter from being discharged together with fine powder and exhaust gas. Furthermore, the invention according to claim 3 of the present application includes the baffle plate according to claim 1 and the rectifying plate according to claim 2 in order to simultaneously achieve the first and second objects. Thus, the synergistic effect can further improve the efficiency of dry classification.

The straightening vane provided in the second and third aspects of the present invention has a width in the range of 300 mm to 500 mm in a cross section along the transport direction of the dry classifying apparatus, and has The angle of inclination to the plate is 60
° to 75 °, and among the vertically adjacent stages, the upper end of the lower rectifying plate is positioned substantially at the center between the lower ends of the rectifying plates adjacent to the upper direction in the transfer direction, and It is desirable that the distance between the upper end of the lower rectifying plate and the lower end of the upper rectifying plate in the transfer direction be in the range of 200 mm to 300 mm. This is because, first, if the upper end of the lower rectifying plate is close to the lower end of the upper rectifying plate, the gas flow cannot be made uniform, and the distance between these upper and lower ends is too small, If the width of the straightening plate is too small, fine powder may solidify on the straightening plate, and if the inclination angle of the straightening plate is too small, fine powder may be deposited on the straightening plate. . On the other hand, if the inclination angle is too large, or if the distance between the ends of the upper and lower rectifier plates or the width of the rectifier plate is too large, a sufficient rectifying effect may not be obtained. Furthermore, in order to reliably and smoothly transfer coal particles having a larger particle size than the fine powder in the transfer direction, the direction of gas ejection from the dispersion plate is oriented in the coal transfer direction, and On the other hand, it is desirable that the angle be set obliquely upward.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 3 are side sectional views of an apparatus for dry classification of coal showing one embodiment of the present invention. In particular, the invention according to claim 3 of the present application, that is, the invention according to claim 1 1 shows an embodiment of a dry classifying apparatus provided with the baffle plate described above and the straightening plate according to the second aspect of the present invention. The apparatus main body 11 of the drying and classifying apparatus of the present embodiment has a substantially box-like shape, and a dispersion plate 12 is horizontally mounted on the bottom inside thereof, and a fluidized bed 13 is provided above the dispersion plate 12. At the same time, hot air is supplied to the lower part of the dispersion plate 12 from the hot air inlet 14 as jet gas G. Further, a supply section 15 for coal C is provided at one end side (right side in FIG. 1) of the fluidized bed 13, and a discharge section through which treated dry coal is discharged at the other end side (left side in FIG. 1). The coal C supplied into the fluidized bed 13 from the supply unit 15 is provided from the one end side to the other end side, that is, in the transfer direction F indicated by a white arrow in the drawing. , Dispersion plate 1
The drying unit 16 is dried while being transported on the second unit 2 and discharged from the discharging unit 16.

Here, as shown in FIG. 2, a large number of air inlets 17 are formed in the dispersion plate 12 so as to extend in a direction perpendicular to the transport direction F, and
Are formed at an interval from each other, and are semi-cylindrical caps 18 so as to cover each air inlet 17.
Are also laid on the dispersion plate 12 in a direction orthogonal to the transport direction F. The cap 18 is provided with a plurality of nozzles 19 at appropriate intervals in the laying direction (a direction orthogonal to the drawing of FIG. 2), each of which is directed toward the transfer direction F and inclined with respect to the dispersion plate 12. It is formed obliquely upward so that the angle θ is 30 ° or less. Further, caps 18 adjacent to each other in the transfer direction F,
Between the upper surface of the dispersing plate 12 in front of the cap 18 on the rear side in the transport direction F and the upper portion of the cap 18 in the transport direction F, a plate-like shape is formed to be inclined upward at an angle equal to the above-mentioned inclination angle θ. Are provided.

The nozzle 19 may have a circular cross section, an elliptical or elliptical shape extending in the installation direction, or a rectangular or trapezoidal shape. Further, instead of the semi-cylindrical cap 18 and the plate-shaped jump table 20 as described above, a cap 18 made of a plate material having a cross-section “H” -shaped in which the nozzle 19 and the jump table 20 are formed is used as the dispersion plate The nozzle 19 and the jump table 20 may be provided by laying on the top or forming the dispersion plate 12 itself in a step shape. However, it is desirable that these nozzles 19 are arranged in a zigzag pattern or the like in a plan view of the dispersion plate 12 to be uniformly dispersed and formed.
In the case where the dispersion plate 12 itself is formed in a stepped shape as described above, the jump table 20 may be similarly dispersedly formed.

On the other hand, above the dispersing plate 12, each crosses the transport direction F of the coal C, and
A plurality of (five in the present embodiment) baffle plates 21 are erected in the transfer direction F at equal intervals. Here, in the present embodiment, these baffle plates 21 are formed in a rectangular flat plate shape, and are oriented so as to be perpendicular to the dispersing plate 12 and the transport direction F of the coal C, and both ends thereof are provided. It is attached to both inner walls of the apparatus main body 11 along the transfer direction F, and is disposed so as to be bridged between these inner walls. These baffle plates 21 are connected to their lower ends 21 as shown in FIG.
The height A of the A from the dispersion plate 12 is set in the range of 200 mm to 450 mm, and the height L from the lower end 21A to the upper end 21B is set in the range of 300 mm to 1000 mm.

In the present embodiment, the distance between the baffle plates 21 in the transfer direction F is substantially equal to each other, and is set in the range of 200 mm to 1000 mm. If the interval is too small, the fluidity of the coal particles in the fluidized bed 3 may be impaired. Conversely, if the interval is too large, the number of baffle plates 21 depends on the size of the apparatus main body 11. This is because there is a possibility that the short path of the fine powder D cannot be prevented effectively. For the same reason, this baffle plate 21
Is desirably about 2 to 5 sheets. on the other hand,
The baffle plates 21 of the present embodiment are attached so as to be stretched between both inner walls of the apparatus main body 11 as described above.
The baffle plate 21 may be provided with a slight space between the baffle plate 21 and the inner wall on the side opposite to the mounting side, so that the baffle plates 21 and 21 are attached to alternate inner walls.

Further, a large number of rectifying plates 23 are provided above the baffle plates 21 so as to be located at the bottom of the free board portion 22 above the fluidized bed 13. These rectifying plates 23 are formed in the shape of a rectangular flat plate like the above-mentioned baffle plates 21, and are installed by being bridged between both inner walls of the apparatus main body 11 in a direction crossing the transport direction F of the coal C. In the present embodiment, such rectifying plates 23 are vertically divided into a plurality of stages, and a plurality of rectifying plates 23 are arranged in each of the stages in the transfer direction F.
They are arranged at equal intervals toward. Further, among these current plates 23, the current plates 23 in adjacent stages in the vertical direction are connected to the dispersion plate 12 in the side cross section along the transfer direction F as shown in FIGS. 1 and 4. They are inclined in opposite directions to each other, and are arranged so as to be shifted in the transport direction F.

Here, in the present embodiment, these rectifying plates 2
3 have the same width W in the side cross section of the apparatus main body 11 along the transfer direction F, as shown in FIG.
mm to 500 mm. In the present embodiment, the rectifying plates 23 are arranged in three stages in the up-down direction, and the rectifying plates 23
.. Are inclined with respect to the dispersion plate 12 so as to be directed downward toward the transfer direction F,
The rectifying plates 23 located at the middle stage between these are arranged such that the rectifying plates 23 move upward in the transport direction F.
Rectifier plate 23 at each stage.
... are arranged in parallel with each other. Further, as shown in FIG. 4, the inclination angle α formed by these rectifying plates 23 with respect to the dispersion plate 12 is equal between the upper and lower tiers and the middle tier, and is in the range of 60 ° to 75 °. Is set to

Further, the rectifying plates 23 arranged in these three stages are provided.
, The rectifying plates 23 of the lower and middle stages and the vertically adjacent stages of the middle and upper stages are arranged at the center of the lower ends 23A and 23A of the adjacent rectifying plates 23 and 23 on the upper stage side in the transfer direction F. Are arranged such that the upper end 23B of the lower rectifying plate 23 is located at the lower end of the rectifying plate 23.
3A, 23A, and the lower rectifying plate 23 located between them.
As shown in FIG. 4, the upper ends 23 </ b> B have the same interval S in the transport direction F. In the present embodiment, the interval S is in a range from 200 mm to 300 mm. However, the lower end 23 of these upper-stage rectifying plates 23
A and the upper end 23B of the lower straightening plate 23 are arranged at the same height in the vertical direction.

As shown in FIG. 1, the baffle plates 23 are arranged only above the dispersion plate 12 in the transfer direction F,
It is arranged so as to reach the inner wall 24 on the one end side (supply section 15 side) of the apparatus main body 11 on the other end side (discharge section 16 side). Further, the inner wall 24 on the other end side of the apparatus main body 11 is provided.
And both inner walls along the transfer direction F are provided with the current plate 23.
At the position where is disposed, the ceiling portion 25 is provided above the rectifying plates 23 with a space in which the free board portion 22 is formed. An exhaust port 26 is provided at the center of the ceiling 25 for discharging the exhaust gas G and the fine powder D classified from the supplied coal C.

In the apparatus for drying and classifying coal according to the present embodiment, a baffle plate 21 is provided above the dispersion plate 12, and a lower end of the baffle plate 21 is provided from the dispersion plate 12. Height H up to 21A is 200
mm to 450 mm and the lower end 2
The height L from 1A to the upper end 21B of the baffle plate 21 is 3
Since it is set in the range of 00 mm to 1000 mm, it is possible to prevent the fine powder D in the supplied raw coal C from flowing shortly and flowing directly into the discharge unit 16, while the coarse coal C particles are dispersed. By the gas G ejected obliquely upward from the nozzle 19 of the plate 12 in the transfer direction F, the gas G can be reliably transferred between the dispersion plate 12 and the lower ends 21A of the baffle plates 21. Therefore, according to the present embodiment, it is possible to prevent clogging due to such coarse particles and to sufficiently dry the supplied coal C and remove the fine powder D while reliably feeding out the supplied coal C in the transport direction F. However, it is possible to reliably prevent the fine powder D that has been short-passed from being mixed with the coal C that has been dried and classified in this manner, and it is possible to further improve the dry classification efficiency.

In addition, in this embodiment, a plurality of rectifying plates 23 are provided above the baffle plates 21, and these rectifying plates 23 are shifted in the transport direction F for each stage. And the gas G in the freeboard portion 22 above the fluidized bed 13 flows in the direction opposite to the distribution plate 12.
3 while being ascended during ascent. Therefore,
According to the present embodiment, it is possible to prevent the drift of the gas G from occurring and to suppress the variation in the superficial velocity, whereby the superficial velocity partially increases and the fine powder D
A situation in which even the particles of the coal C having a larger particle diameter than the coal C are discharged from the exhaust port 26 is prevented, that is, only the fine powder D to be classified can be discharged from the exhaust port 26. Classification efficiency can be further improved. Also, as described above, the free board 22
The flow of the gas G in the step is made uniform and the discharge of the large-sized particles from the exhaust port 26 is prevented, so that the height from the dispersion plate 12 to the ceiling 25 of the apparatus main body 11 can be reduced. Therefore, it is possible to provide a compact and efficient and economical dry classification apparatus.

In the present embodiment, the apparatus main body 11 is thus provided with the baffle plates 21 and the rectifying plates 23 at the same time. Therefore, as described above, for the raw coal C having a wide particle size distribution, However, even if the particle size distribution and the water content of the supplied raw coal C slightly fluctuate, the effects of the baffle plates 21 and the effects of the rectifying plates 23 are combined to produce a synergistic coal. The efficiency of dry classification of C can be improved. However, in the present embodiment, both the baffle plates 21 and the rectifying plates 23 are provided at the same time in the apparatus main body 11 as described above. However, only one of them may be provided. The effect can improve the efficiency of dry classification of coal C.

In this embodiment, the rectifying plate 23 is formed in three stages in the vertical direction. However, it may be at least two stages or more. However, the rectifying plates 23.
Even if the rectifying plate 23 is formed in two or more steps, the rectifying effect is not significantly improved compared to the case of three steps, and the height of the apparatus main body 11 may be rather increased. It is desirable to have three stages. The lowermost rectifying plate 2
3 are inclined in the same manner as in this embodiment.
Is set in such a manner that the direction in which the gas G is blown out is directed in the transport direction F of the coal C and is inclined obliquely upward with respect to the dispersion plate 12 as described above in consideration of this. It is desirable to be directed downward in the transport direction F. Further, the position where these rectifying plates 23 are installed is set in the range of 600 mm to 2000 mm from the dispersion plate 12, though it depends on the heights H and L of the baffle plates 21 if there are any. Is desirable. This is the current plate 23 ...
Is too low, the flow of the gas G and the particles of the coal C in the fluidized bed 13 may interfere with each other. On the other hand, if the positions of the flow straightening plates 23 are too high, a sufficient flow straightening effect can be expected. This is because there is a risk of disappearing.

[0024]

Next, the effects of the present invention will be demonstrated with reference to examples. In the present example, the dry classification operation of the raw coal C was performed using the coal C dry classification apparatus described in the above embodiment, and this was not provided with the baffle plates 21 and the rectifying plates 23 as comparative examples. This was compared with the case where dry classification was performed under the same operating conditions using the same type of dry classification device. However,
The particle size distribution of the raw material coal C supplied at this time is as shown in FIG. 5, the water content is 4.5%, and the supply amount is 300 ton / h.
Met. In the embodiment, the height H from the dispersion plate 12 to the lower end 21A of the baffle plate 21 is 300 mm,
The height L of the baffle plate 21 from 1A to the upper end 21B is 6
00 mm, the width W of the current plate 23 is 500 mm, the inclination angle α of the current plate 23 with respect to the dispersion plate 12 is 60 °, and the upper current plate 23 adjacent to the upper end 23B of the lower current plate 23.
The distance S in the transport direction F from the lower end 23A was 250 mm. Further, in both the example and the comparative example, the inclination angle θ of the nozzle 19 of the dispersion plate 12 was 20 °, and the ejection speed of the gas G was 50 m / s.

In this embodiment, first, at the position of the XX section in FIG. 1 (the position just below the lower end 21A of the baffle plate 21), as shown in FIG.
The center lines of the equally divided regions are 1 to 6, and the center lines of the approximately three equally divided regions in the width direction of the apparatus main body 11 are A to
C, and particles of the coal C were sampled by the same amount at the positions of intersections 1-A, 1-B,..., 6-C between the center lines 1 to 6 and the center lines A to C. Then, the three samples sampled on the respective intersections of the center lines 1 to 6 are mixed and analyzed, and the supplied raw coal C is supplied.
Was examined as to how the particle size distribution and the water content change in the transfer direction F. Also in the comparative example, the same sampling was performed at the same position as the above-mentioned cross section, and analyzed. The results are shown in FIG. 7 for the particle size distribution and in FIG. 8 for the water content.

7 and 8, in the comparative example having no baffle plates 21..., The content of the fine powder D having a particle size of 105 μm or less decreases partway toward the transfer direction F. However, the water content increased on the discharge side of the apparatus body, and the water content tended to increase on the discharge side. It is recognized that this is because the fine powder D of the coal C supplied from the supply unit to the fluidized bed was directly transferred to the discharge unit via a short pass. However, in the embodiment provided with the baffle plates 21..., On the other hand, the content and the water content of the fine powder D tend to gradually decrease toward the transfer direction F side. In each case, they were almost the minimum, and it was confirmed that the efficiency of dry classification was improved.

Next, in this embodiment, at the position of the YY cross section in FIG. 1 (the position immediately above the current plate 23), FIG.
As shown in FIG.
The equally divided equal lines are denoted by A to D, and the dispersion plate 12
Are set at equal intervals in the transport direction F above the line, and the intersection 1-1 of these interval lines 1 to 4 and the equal lines A to D is set.
A, 1-B,.
2. The superficial velocity was measured at the intersection 2-
At the positions of A, 2-D, 4-A and 4-D, fine powder D and the like were sampled, and the particle size distribution and dust concentration were analyzed. The same measurement and sampling were performed for the comparative example. The results are shown in Table 1 below for the superficial velocity, FIG. 10 for the particle size distribution of the fine powder D and the like, and FIG. 11 for the dust concentration.

[0028]

[Table 1]

First, from the results shown in Table 1, the current plates 23.
In the comparative example having no superficial superficial velocity, the superficial superficial velocity is extremely large, and particularly, the maximum superficial superficial velocity is extremely high. The maximum superficial superficial velocity is also suppressed to half or less of the comparative example. In addition, the particle size distribution of the fine powder D and the like sampled in accordance therewith also shows that the content of the fine powder D having a particle size of 105 μ The particle content was found to be low, and the sampled dust concentration was lower in each of the examples than in the comparative example. As a result, the fine powder D is efficiently removed together with the exhaust gas G by the equalization of the superficial velocity by the flow straightening plates 23..., While the coal C particles having a large particle diameter are surely discharged from the exhaust port 26. It was confirmed that it was prevented.

[0030]

As described above, according to the first aspect of the present invention, the height of the lower end of the baffle plate provided above the dispersion plate from the dispersion plate is set in the range of 200 mm to 450 mm. By setting the height from the lower end to the upper end of the baffle plate to 300 mm to 1000 mm, it is possible to prevent the fine powder of coal supplied to the fluidized bed from short-circuiting to the discharge section. According to the second aspect of the present invention, the upper part of the fluidized bed is provided with a plurality of rectifying plates which are displaced in the coal transfer direction and are inclined in the opposite direction with respect to the dispersion plate. And the superficial velocity in the freeboard section of the above can be made uniform to prevent large-sized coal particles from being discharged together with the exhaust gas. Therefore, according to the coal classification apparatus of the present invention, even in the classification of coal having a wide particle size distribution, and even when the particle size distribution and the water content vary, the efficiency of the classification is improved. Can be. Furthermore, in the invention according to claim 3, by providing such a baffle plate and a flow regulating plate at the same time, the dry classification efficiency can be further improved by a synergistic effect of these.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged side sectional view showing the dispersion plate 12 of the embodiment shown in FIG.

FIG. 3 is an enlarged sectional side view showing the baffle plates 21 of the embodiment shown in FIG.

FIG. 4 is an enlarged sectional side view showing the current plates 23 of the embodiment shown in FIG.

FIG. 5 is a diagram showing a particle size distribution of raw coal C supplied in an example of the present invention.

FIG. 6 is a sectional view taken along the line XX of FIG. 1 showing a sampling position in the embodiment of the present invention.

7 shows the particle size distribution at sampling positions 1 to 6 in FIG. 6, wherein (a) is a comparative example, (b) is an example,
(C) is a description of the reference numerals in the figure.

8 shows the water content at sampling positions 1 to 6 in FIG. 6, wherein (a) is a comparative example and (b) is an example.

FIG. 9 is a YY sectional view of FIG. 1 showing a sampling position in the embodiment of the present invention.

10 shows the particle size distribution at the sampling position in FIG. 9, (a) is 2-A, (b) is 2-D,
(C) is the measurement result at 4-A, and (d) is the measurement result at 4-D.

11 shows sampling positions 2-A, 2-D,
It is a figure which shows the dust density measured in 4-A and 4-D.

FIG. 12 is a side sectional view showing a conventional coal C dry classification apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 Apparatus main body 12 Dispersion plate 13 Fluidized bed 15 Supply part 16 Discharge part 19 Nozzle 21 Baffle plate 21A Lower end of baffle plate 21B Upper end of baffle plate 22 Free board part 23 Rectifier plate 23A Lower end of rectifier plate 23B Upper end of rectifier plate 26 Exhaust port C Coal G Gas (exhaust) D Fine powder F Transfer direction of coal C H Height from dispersion plate 12 to lower end 21A of baffle plate 21 L Height from lower end 21A to upper end 21B of baffle plate W W straightening plate 23 The distance S in the transport direction F between the upper end 23B of the lower rectifying plate 23 and the lower end 23B of the upper rectifying plate 23. The inclination angle of the rectifying plate 23 with respect to the dispersing plate 12. The inclination angle of the nozzle 19 of the dispersing plate 12.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Tatsuo Arakura, Inventor 2-17-15 Tsukushima, Chuo-ku, Tokyo Tsukishima Machinery Co., Ltd. Inside Machinery Co., Ltd. Within the Development Headquarters (72) Junichiro Ikenaga 1-1, Tobata-cho, Tobata-ku, Kitakyushu-shi, Fukuoka Prefecture Nippon Steel Corporation Yawata Works (72) Inventor Yoji Nakagawa 46 59 Inside Nippon Steel Plant Design Co., Ltd.

Claims (5)

[Claims] 1. A coal dry classification apparatus using a fluidized bed for transporting and drying and classifying coal while fluidizing by a fluidized bed formed by gas ejected from a dispersion plate, wherein the above-mentioned dispersion plate has A baffle plate is erected so as to traverse the coal transfer direction, and the lower end of the baffle plate is located at a height in the range of 200 mm to 450 mm from the dispersion plate, and the height from the lower end to the upper end. Saga 300
An apparatus for drying and classifying coal using a fluidized bed, characterized in that the diameter is in the range of mm to 1000 mm. 2. A coal dry classification apparatus using a fluidized bed formed by a gas ejected from a dispersion plate and transporting and drying and classifying coal while flowing the coal. A plurality of rectifying plates extending in a direction crossing the coal transfer direction are provided in the transfer direction, and a plurality of rectifier plates are provided in the vertical direction. A coal dry classification apparatus using a fluidized bed, characterized in that, in a side cross section along a direction, the dispersion plate is inclined with respect to the dispersing plate in directions opposite to each other and is displaced in the transport direction. 3. A coal drying and classifying apparatus using a fluidized bed for transporting and drying and classifying coal while flowing the coal by means of a fluidized bed formed by gas ejected from the dispersion plate. A baffle plate is erected so as to traverse the coal transfer direction, and the lower end of the baffle plate is located at a height in the range of 200 mm to 450 mm from the dispersion plate, and the height from the lower end to the upper end. Saga 300
In the upper part of the fluidized bed, a plurality of straightening plates extending transversely to the coal transfer direction are provided in the upper part of the fluidized bed, and a plurality of straightening plates are provided in the transfer direction in a plurality of stages in the vertical direction. The rectifying plates of the vertically adjacent stages are inclined in opposite directions with respect to the dispersing plate in a side cross section along the transfer direction, and are arranged so as to be shifted in the transfer direction. An apparatus for drying and classifying coal using a fluidized bed. 4. In a side cross section along the transfer direction,
The width of the rectifying plate is set in a range of 300 mm to 500 mm, and the inclination angle of each rectifying plate with respect to the dispersion plate is 60 °.
And the upper end of the lower rectifying plate is positioned substantially at the center between the lower ends of the rectifying plates adjacent to the upper direction in the transfer direction. The fluidized bed according to claim 2 or 3, wherein a distance between the upper end of the lower rectifying plate and the lower end of the upper rectifying plate in the transfer direction is in a range of 200 mm to 300 mm. For drying and classifying coal. 5. The gas jetting direction from the dispersion plate is set to be inclined obliquely upward with respect to the distribution plate in a direction in which the coal is conveyed. An apparatus for drying and classifying coal using the fluidized bed according to any one of claims 1 to 4.