JP2008264658A - Fluidized bed drying and classifying apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluidized bed drying and classifying apparatus in which no gap is generated between a drying and classifying chamber and a dispersion plate and/or between a gas chamber and a dispersion plate, even when the drying and classifying chamber and/or the gas chamber are thermally deformed. <P>SOLUTION: In the fluidized bed drying and classifying apparatus where a fluidized bed 16 is formed over the dispersion plate 15 in the drying and classifying chamber 14 by jetting gas, introduced into the gas chamber 26, through the dispersion plate 15 to dry coal and, at the same time, to classify powdered coal in coal generated by the drying, the drying and classifying chamber 14 is fixed, and a pressing means (a support member 41) for pressing the gas chamber 26 to the dispersion plate 15 is installed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  In the present invention, the gas introduced into the gas chamber is ejected through a dispersion plate having a plurality of gas ejection ports, thereby forming a fluidized bed on the dispersion plate, drying the coal, and roughing the dry coal. The present invention relates to a fluidized bed drying and classifying apparatus for classifying granular coal and pulverized coal.

  In a normal blast furnace coke manufacturing process, from the viewpoint of improving coke strength by increasing the charging bulk density and improving productivity by shortening the carbonization time, coal containing about 8-12% moisture is dried and about 6% or less. After reducing the amount of water until, it is charged into a coke oven.

  However, if the moisture content in the coal is reduced due to the drying of the coal, the amount of fine powder of about 0.5 mm or less that is likely to generate dust increases, which causes the working environment to deteriorate. For this reason, after drying the coal or separating the pulverized coal of about 0.5 mm or less generated by drying at the same time as drying the coal from the coarse coal by classification, adding a binder to the pulverized coal, kneading, After the grain or the molding, the coarse coal is mixed and charged into the coke oven.

  Conventionally, for example, a configuration shown in Patent Document 1 is known as a fluidized bed drying and classifying device having functions of a coal dryer and a classifier.

  In Patent Document 1, high-temperature gas is introduced into a gas chamber from a hot air duct, and the introduced gas is inclined obliquely upward with respect to the coal transfer direction from a plurality of nozzles provided on the dispersion plate. By ejecting, a fluidized bed is provided for transporting coal while flowing in the dry classification chamber. The dispersion plate is generally fastened and fixed to the drying classification chamber and the gas chamber by a fastening mechanism including bolts and nuts.

  In the blast furnace coke manufacturing process, the coke oven charge density is increased by increasing the coke oven charge bulk density, and the productivity of the coke oven is reduced by shortening the carbonization time. Charcoal charging is required.

For this reason, it is necessary to raise the temperature of the gas introduced into the fluidized bed drying classifier through the gas chamber, to further reduce the amount of water in the coal, and to raise the temperature of the dried coal.
JP-A-8-219655

  However, when the temperature of the heated gas introduced into the drying classification chamber through the gas chamber and the dispersion plate becomes high, the thermal expansion of the drying classification chamber and the gas chamber increases during operation, and the dispersion plate by the bolts and nuts, etc. With this fastening mechanism, the fastening force may be weakened due to thermal expansion.

  As a result, a gap is generated between the dispersion plate, the drying classification chamber, and the gas chamber during operation, and the heated gas may be ejected therefrom. Since the heated gas contains a volatile component of coal and a partially pyrolyzed component and also contains CO gas, it is desired that the heated gas further reduce the ejection amount.

  Further, when the temperature of the heated gas is increased, a temperature distribution of the gas atmosphere in the drying classification chamber is generated in the moving direction of the fluidized bed during operation, and the amount of thermal expansion differs according to this temperature distribution. A difference in gap amount is likely to occur between the dispersion plate in the dry classification chamber and the gas chamber and the dry classification chamber and the gas chamber. Furthermore, the dispersion plate may be deformed in the plate thickness direction due to thermal expansion.

  Therefore, the present invention is caused by thermal expansion or thermal deformation between the drying classification chamber and / or the gas chamber and the dispersion plate when the fluidized bed drying classification apparatus is operated under a condition where the temperature of the heated gas is high. An object of the present invention is to provide a fluidized bed drying / classifying apparatus capable of preventing the generation of gaps.

  In order to solve the above problems, the present invention forms a fluidized bed on the dispersion plate in the drying classification chamber by ejecting the gas introduced into the gas chamber through the dispersion plate, and simultaneously drying the coal by drying. A fluidized bed drying and classifying device for classifying pulverized coal in generated coal, wherein either one of the drying classification chamber and the gas chamber is fixed and has a pressing means for pressing the other against the dispersion plate. It is characterized by.

  Here, the pressing force by the pressing means can be increased in accordance with the thermal expansion of the drying classification chamber by the gas. The pressing means may be a spring, and an adjustment mechanism for adjusting the length of the spring may be provided.

  Fastening means for fastening the dispersion plate to the dry classification chamber and the gas chamber, and first and second flange portions provided on the outer peripheral surfaces of the dry classification chamber and the gas chamber, respectively, The fastening means may be provided on the first and second flange portions.

  The drying classification chamber includes a drying zone for drying coal, and a classification zone for removing pulverized coal from coal dried in the drying zone, and the pressing means is disposed at a position corresponding to the drying zone. It has a 1st press means and the 2nd press means arrange | positioned in the position corresponding to the said classification zone, It is good to set the spring constant of the said 2nd press means higher than the said 1st press means. . The one and the other are preferably the drying classification chamber and the gas chamber, respectively.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view showing the overall configuration of the drying classification apparatus of the present invention. In FIG. 1, the adjustment mechanism for adjusting the length of the spring constituting the support member 41 is omitted. FIG. 2 is a partially enlarged view of FIG. 1 illustrating a fastening structure of the dispersion plate, the drying classification chamber, and the gas chamber. FIG. 3A is a plan view of the gas chamber showing the positions supported by a plurality of support members, and FIG. 3B shows the structure of the support member and the adjusting mechanism for adjusting the length of the spring in the support member. FIG.

  In FIG. 1, 11 is a wet coal hopper for storing raw coal before drying classification, 12 is a cutting device for taking out a predetermined amount of raw coal, 13 is an inlet, and the cutting device 12 from the wet coal hopper 11. A predetermined amount of raw coal taken out by the above is charged into the drying classification chamber 14 through the inlet 13.

  The dry classification chamber 14 is provided with an inlet 13 at one end in the horizontal direction (Y-axis direction), and a dry coal discharge port (not shown) is provided at the other end. The dry coal discharge port is provided with dry-classified coal. A discharge device (not shown) for discharging a predetermined amount is attached.

  A fixing member 20 extending in the circumferential direction is provided on the outer peripheral surface of the drying classification chamber 14, and the drying classification chamber 14 is fixed to the installation surface 21 by the fixing member 20. Here, the attachment position of the fixing member 20 is set to substantially the same height as the center of gravity of the drying classifier. Thereby, the earthquake resistance of the drying classifier can be improved.

  A first dispersion plate fixing flange (first flange portion) 14c is attached to the lower end portion of the outer peripheral surface of the drying classification chamber 14, and a dispersion plate attachment is attached to the first dispersion plate fixing flange 14c. An insertion port for inserting the bolt (fastening means) 22 in the vertical direction is formed.

  The drying classification chamber 14 is divided into two in the Y-axis direction (coal flow direction) by a partition wall 25, and the upstream side of the partition wall 25, that is, the inlet 13 side is defined as a drying zone 14 a. The downstream side, that is, the dry coal discharge port side is set as the classification zone 14b.

  Exhaust ducts 19a and 19b for discharging fine coal particles together with exhaust gas are provided on the ceilings of the drying zone 14a and the classification zone 14b. Cyclone dust collectors 24a and 24b are attached to the exhaust ducts 19a and 19b via pipes, respectively, and separate pulverized coal particles and exhaust gas.

  The pulverized coal particles separated by the dust collectors 24a and 24b are appropriately discharged by the pulverized powder discharging devices 27a and 27b. The drying zone 14a means a region mainly intended for drying coal, and the drying zone 14a has a higher moisture content in the coal than the classification zone 14b, so the amount of pulverized coal in the exhaust gas is relatively small. However, the pulverized coal is recovered by the dust collector 24a.

  A dispersion plate 15 is disposed in the lower part of the drying classification chamber 14, and a number of gas ejection holes are formed in the dispersion plate 15 at predetermined intervals. Gas can be ejected upward through the holes. The fluidized bed 16 can be formed on the dispersion plate 15 by jetting gas into the dry classification chamber 14 via the dispersion plate 15.

  At the horizontal end of the dispersion plate 15, the dispersion plate protrusion 15a protruding outside the drying classifier is at least at the center position in the X-axis direction at both ends in the Y-axis direction and at both ends in the X-axis direction. It is formed at a total of four locations in the central position in the Y-axis direction (details are shown in FIG. 2), and the dispersion plate mounting bolts 22 are inserted through the dispersion plate protrusions 15a in the thickness direction of the dispersion plate 15. The insertion hole is formed.

  The dispersion plate protrusion 15a is attached at a position that becomes a base point of elongation in the X-axis direction due to thermal expansion at both ends in the Y-axis direction, and in the Y-axis direction due to thermal expansion at both ends in the X-axis direction. It is preferable to provide it at a position that becomes a base point, and it can be provided at a plurality of locations other than the four locations that become the base point of these elongations.

  Below the dispersion plate 15 is a gas chamber 26, which is disposed on the heating coal chamber 26 a for forming a drying fluidized bed disposed on the charging inlet 13 side and on the dry coal discharge port side. And a heating gas chamber 26b for forming a fluidized bed for classification. A gas chamber partition wall 26d is provided between the heated gas chambers 26a and 26b.

  A heating gas having a pressure and a flow rate sufficient to form a fluidized bed is introduced from the hot air generator 23 into the heating gas chambers 26 a and 26 b through the hot air duct 18. In the illustrated apparatus, a hot air flow rate control valve (not shown) is attached to each of the hot air ducts 18 connected to the heating gas chambers 26a and 26b, and the flow rate of the heated gas is set to an arbitrary value by the hot air flow rate control valve. In addition, each heating gas chamber 26a, 26b can be adjusted independently.

  A second dispersion plate fixing flange (second flange portion) 26c is attached to the upper end of the outer peripheral surface of the gas chamber 26, and the dispersion plate attachment bolt 22 is attached to the second dispersion plate fixing flange 26c. An insertion port is formed for allowing the to be inserted vertically.

  The dispersion plate mounting bolts 22 are inserted into the respective insertion openings of the first and second dispersion plate fixing flanges 14c and 26c and the dispersion plate protrusion 15a, and the dispersion plate mounting nuts (fastening means) are connected to the dispersion plate mounting bolts 22. By fastening 36, the dispersion plate 15 can be fixed to the drying classification chamber 14 and the gas chamber 26.

  As shown in FIG. 1 and FIG. 3A, between the gas chamber 26 and the installation surface 38, eight support members (pressing means) 41 for supporting the drying classifier are provided at substantially equal pitches. . The configuration of the support member 41 will be described in detail with reference to FIG.

  The support member 41 includes a contact portion 41a that contacts the lower surface of the gas chamber 26, a spring 41b that applies a pressing force that presses the gas chamber 26 against the dispersion plate 15 via the contact portion 41a, and a tip of the spring 41b. And a flange plate 41c attached to the portion. Further, the spring constant of the spring 41b of the support member 41 arranged in the region corresponding to the classification zone 14b is set higher than that of the drying zone 14a.

  The adjustment mechanism 42 includes a screw rod 42a having a thread groove formed on the outer peripheral surface, a spring adjustment plate 42b that contacts the upper surface of the flange plate 41c, and a spring adjustment nut that is fastened to the screw rod 42a from above the spring adjustment plate 42b. 42c.

  The screw rod 42a is fixed to the installation surface 38, and extends in the vertical direction (Z-axis direction) through an opening formed in the approximate center of the spring adjustment plate 42b. Note that no screw groove is formed in the opening of the spring adjustment plate 42b.

  The spring adjustment nut 42c fastened to the screw rod 42a is in contact with the upper surface of the spring adjustment plate 42b. In the above-described configuration, when the spring adjustment nut 42c is rotated in the direction of arrow G, the spring adjustment plate 42b moves downward while contacting the spring adjustment nut 42c, and the support member 41 that contacts the lower surface of the spring adjustment plate 42b. The flange plate 41c moves downward while charging the spring 41b in the shortening direction.

  On the other hand, when the spring adjustment nut 42c is rotated in the direction opposite to the arrow G direction, the flange plate 41c and the spring adjustment plate 42b are moved upward by the spring force of the charged spring 41b. Further, when the drying classification chamber 14 and the gas chamber 26 are thermally expanded in a state where the flange plate 41 c and the spring adjustment plate 42 b are in contact with each other, the contact plate 41 a is pushed downward through the gas chamber 26. Thereby, the spring 41b is charged in the shortening direction, and the gas chamber 26 can be pressed against the dispersion plate 15 with a stronger reaction force than before thermal expansion.

  Next, the operation method of the drying classifier of the present embodiment will be described with reference to FIG. When the drying classifier is in operation, the heated gas of about 400 ° C. from the hot air generator 23 is adjusted to a predetermined flow rate by the hot air flow rate control valve and supplied into the heating gas chambers 26a and 26b.

  On the other hand, undried unclassified raw coal in the wet coal hopper 11 is supplied into the dry classification chamber 14 through the inlet 13 by a predetermined amount by the cutting device 12. Therefore, the raw coal is first stirred on the dispersion plate by the heated gas blown into the drying zone 14a in the drying classification chamber 14 through the plurality of gas ejection holes of the dispersion plate, from the coal inlet 13 side to the coal discharge side. Forming a fluidized bed that moves to

  The coal dried mainly in the drying zone 14a is further dried and the pulverized coal in the coal is easily dissociated, and the pulverized coal is mainly discharged together with the heating gas in the classification zone 14b from the outlet provided on the ceiling. This separates the pulverized coal.

  Here, since the drying classification chamber 14 and the gas chamber 26 are thermally expanded by the gas introduced from the hot air duct 18 during operation, when the operation time is long under the condition where the temperature of the heated gas is high, the dispersion plate is attached by thermal expansion. The fastening force by the bolt 22 is weakened. As a result, a gap is generated between the dispersion plate 15 and the drying classification chamber 14 and the gas chamber 26, and there is a possibility that gas is ejected therefrom.

  However, in this embodiment, when the drying classification chamber 14 and the gas chamber 26 are thermally expanded, the spring 41b of the support member 41 is charged in the shortening direction, so that the gas chamber 26 is dispersed with a reaction force stronger than before the thermal expansion. 15 can be pressed.

  Thereby, it is possible to reliably prevent a gap from being formed between the dispersion plate 15 and the drying classification chamber 14 and the gas chamber 26. Moreover, the temperature of the introduced gas can be set high by improving the sealing performance of the drying classifier in this way.

  As a result, the amount of water in the coal can be further reduced, the temperature of the coal charged into the coke oven is increased, the bulk density of the charged coal in the coke oven is increased, and the dry distillation time can be shortened. As a result, coke strength can be improved and coke productivity can be improved.

  Further, in the drying zone 14a, compared with the classification zone 14b, the heated gas exchanges heat with low-temperature coal containing a large amount of moisture, so that the amount of moisture in the gas in the upper space is high and the gas temperature is low. As a result, the gas temperature in the drying classification chamber is higher in the classification zone 14b than in the drying zone 14a, and the thermal expansion coefficient of the drying classification chamber is higher.

  Depending on the distribution of the thermal expansion amount of the drying classification chamber in the moving direction of the fluidized bed, the spring 41b of the support member 41 arranged in the region corresponding to the classification zone 14b having a larger thermal expansion than the drying zone 14a. By setting the spring constant high, the fastening force of the dispersion plate 15 during operation can be increased, and the generation of a gap between the dispersion plate 15 and the drying classification chamber 14 and the gas chamber 26 can be suppressed.

  Next, replacement work of the dispersion plate 15 will be described. Since the dispersion plate 15 is worn by being installed in the fluidized bed 16 or a high-temperature gas environment for a long period of time, it needs to be periodically replaced.

  First, the gas chamber 26 is fixed by support means such as a hydraulic jack. Next, with the gas chamber 26 fixed, the spring adjustment nut 42c of the adjustment mechanism 42 is rotated in the arrow G direction. Thereby, the contact portion 41 a of the support member 41 can be moved downward and separated from the bottom surface of the gas chamber 26.

  Next, the dispersion plate attachment nut 36 is removed from the dispersion plate attachment bolt 22, and the dispersion plate attachment bolt 22 is pulled out from the respective insertion openings of the first and second dispersion plate fixing flanges 14 c and 26 c and the dispersion plate protrusion 15 a and dispersed. The fastening of the plate 15 with the drying classification chamber 14 and the gas chamber 26 is released.

  Next, the hydraulic jack is driven to move the gas chamber 26 and the dispersion plate 15 downward to form a replacement gap between the dispersion plate 15 and the drying classification chamber 14. The dispersion plate 15 is pulled out from the gap to the outside of the drying classifier, the thinned portion of the drawn dispersion plate 15 is cut by a cutting device, and a new dispersion plate is welded to the cut portion to replace the dispersion plate. It can be performed. Thus, according to the present embodiment, the dispersion plate 15 can be repaired simply by operating the adjustment mechanism 42 and shortening the spring 41b.

(Other examples)
In the above-described embodiment, the drying classification chamber 14 is fixed. However, the gas chamber 26 may be fixed, and a pressing unit that applies a pressing force to the dispersion plate 15 may be provided on the drying classification chamber 14 side. Further, the present invention can also be applied to a dry classification apparatus that performs drying and classification using the entire region of the dry classification chamber.

  In addition, the gas ejection direction of the gas ejected from the dispersion plate 15 can be an inclined direction inclined with respect to the vertical direction.

  Further, the adjustment mechanism 42 can be omitted. In this case, the installation surface 38 can be moved up and down, and the dispersion plate 15 can be replaced by lowering the installation surface 38 with the gas chamber 26 fixed.

  Moreover, in the replacement | exchange operation | work of the dispersion | distribution board 15, although the gas chamber 26 was fixed with the hydraulic jack, it can also be set as the structure suspended with linear members, such as a wire.

It is a schematic sectional drawing which shows the whole structure of the drying classification apparatus of this invention. It is the elements on larger scale of FIG. 1 which illustrated the fastening structure of a dispersion plate, a drying classification chamber, and a gas chamber. (A) is the top view of the gas chamber which showed the support position with respect to the gas chamber bottom face of a some support member, (b) is a structure which shows the structure of the adjustment mechanism which adjusts the length of the support member and the spring in a support member FIG.

Explanation of symbols

11 Wet coal hopper
12 Cutting device
13 Loading port
14 Drying classification room
14a Drying zone
14b Classification zone
14c First dispersion plate fixing flange
15 Dispersion plate
16 Fluidized bed
18 Hot air duct
19 Exhaust duct
20 Fixing member
21 38 Installation surface
22 Dispersion plate mounting bolt
24 Dust collector
26 Gas chamber
26c Second dispersion plate fixing flange
36 Dispersion plate mounting nut
41 Support member
41a Contact part
41b Spring
41c Flange plate
42 Adjustment mechanism
42a Screw rod
42b Spring adjustment plate
42c Spring adjustment nut

Claims (6)

A fluidized bed that forms a fluidized bed on the dispersion plate in the drying classification chamber by ejecting the gas introduced into the gas chamber through the dispersion plate, and simultaneously classifies the pulverized coal in the coal generated by drying. A drying classifier,
One of the drying classification chamber and the gas chamber is fixed, and the fluidized bed drying classification apparatus has pressing means for pressing the other against the dispersion plate.   The fluidized bed drying classifying apparatus according to claim 1, wherein the pressing force by the pressing means increases in accordance with the thermal expansion of the drying classification chamber due to the gas.   The fluidized bed drying / classifying apparatus according to claim 1 or 2, wherein the pressing means is a spring and has an adjusting mechanism for adjusting the length of the spring. Fastening means for fastening the dispersion plate to the drying classification chamber and the gas chamber;
A first flange portion and a second flange portion provided on the outer peripheral surfaces of the dry classification chamber and the gas chamber,
The fluidized bed drying and classifying apparatus according to any one of claims 1 to 3, wherein the fastening means is provided in the first and second flange portions. The drying classification chamber comprises a drying zone for drying coal, and a classification zone for removing pulverized coal from coal dried in the drying zone,
The pressing means includes a first pressing means disposed at a position corresponding to the drying zone, and a second pressing means disposed at a position corresponding to the classification zone,
The fluidized bed drying classifier according to claim 3 or 4, wherein a spring constant of the second pressing means is set higher than that of the first pressing means. The fluidized-bed drying classification apparatus according to any one of claims 1 to 5, wherein the one and the other are the drying classification chamber and the gas chamber, respectively.

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