JPH077311Y2 - Coal drying / classifying equipment - Google Patents

Description

[Detailed Description of the Invention] [Industrial application] The present invention relates to a drying / classifying device for drying coal to a desired water content and classifying it into fine / fine-grained coal and coarse-grained coal at a desired classification point. Is.

[Prior Art] For example, as a measure for reducing the cost of blast furnace coke, a coking coal blending method in which a part of the charging coal in the coke furnace is replaced with coking coal is used in many coke plants.

As a method for producing this shaped coal, for example, as proposed in Japanese Patent Laid-Open No. 59-4681, a wet raw material coal pulverized by a pulverizer is preheated and dried by a dryer, and the dried pulverized raw material coal is classified by a classifier. Classify into fine / fine grain coal with a grain size or less and coarse grain coal with a grain size larger than this, and mix this fine / fine grain coal with the fine grain coal collected with a dust collector from the exhaust gas flowing out from the dryer. Coke for blast furnace is supplied to a roll-type pressure molding machine and pressure-molded into a flat plate to form agglomerated coal, and the agglomerated coal is mixed with the classified coarse-grained coal and charged into a coke oven. There is a method of manufacturing.

[Problems to be Solved by the Invention] However, in the method proposed in Japanese Patent Laid-Open No. 59-4681, a dryer and a classifier must be provided respectively, and since dried crushed coking coal is easily dusted. Since the conveyance path must be closed between the dryer and the classifier, the equipment cost is high.

[Means for Solving the Problems] The present invention eliminates the need for an independent dryer (or classifier) by classifying coal while drying it in the same device, and at the same time, provides a closed transfer path between the dryer and the classifier. The equipment cost is reduced by omitting, and the hot air having a low flow rate introduced from the lower side of the horizontally arranged dispersion plate conveys the coal supplied onto the dispersion plate while fluidizing it, and the hot air is supplied to the upper part. The flow-drying chamber communicating with a discharge pipe for discharging the coal and the hot air having a high flow rate introduced from the lower side of the dispersion plate arranged in the horizontal direction further discharge the coal flow-conveyed from the flow-drying chamber to the dispersion plate on the discharge path side. Adjustment to adjust the discharge of hot air containing the blown up fine / fine grained coal by blowing up the fine / fine grained coal and classifying it into the fine / fine grained coal and coarse grain coal while flowing and conveying A wind classification chamber connected with a discharge pipe having a valve, the fluidized drying chamber and the wind separation chamber. A partition wall for partitioning the class chamber with the coal passage left, and hot air flowing through the discharge pipe provided at the upper part of the fluid drying chamber and the air classifying chamber are introduced, and fine and fine coal particles accompanied by the hot air are introduced. A dust collector to collect, a cutting device for adjusting the amount of coarse coal cut out provided in a discharge path for discharging the coarse coal that has been fluidly conveyed on the dispersion plate of the air classification chamber, the fluid drying chamber and the wind The means 1 has a hot air temperature adjuster for adjusting the temperature of hot air supplied from the bottom of the classification chamber.

In the above-mentioned means 1, a partition wall for partitioning the fluidized drying chamber and the air classification chamber is provided so as to be movable up and down.

In the means 1, the means 3 is provided with an opening having an adjustable opening area in the middle of the partition wall which divides the fluidized drying chamber and the air classification chamber.

[Operation] The operation of the present invention will be described with reference to FIG.

The inventors of the present invention have conducted various experiments and studies on a device that has a function of drying the raw coal C to a desired water content and classifying the dried raw coal at a desired classification point. As a result, hot air is supplied from below. Then, a fluidized dryer that dries the raw coal while moving it in the horizontal direction is the most suitable, and this fluidized dryer fluidizes the raw coal C during the drying to agglomerate the fine powders with each other, and attach the fine powders to the coarse particles. It was found that the accuracy of classification of fine and fine-grained coal and coarse-grained coal is improved by crushing.

In this fluidized dryer, it is divided into two chambers by partition walls 9 and 13, and the upstream side (coking coal charging side) area is used as the original drying area, and the downstream side (coking coal discharging side) area is mainly classified. The area.

In this fluidized drying area, that is, a fluidized drying chamber (hereinafter simply referred to as a drying chamber) 2, the hot air from the hot air supply technique tube 5 has a low superficial velocity of 0.1 to 3 m / s which does not scatter the fine coal in the coking coal C. As the raw material carbon C, the raw material coal C is fluidized and dried while crushing the agglomeration of the fine powder and the adhesion of the fine powder to the coarse particles.

Further, in the wind force classification area, that is, the wind force classification chamber 3 (hereinafter simply referred to as the classification chamber), the dried coking coal C is transported horizontally while being strongly fluidized by hot air with a high superficial velocity of about 4 to 10 m / s. By doing so, the cohesion of the dried raw coals with each other and the adhesion of the fine coals to the coarse coals are crushed more strongly than the drying chamber 2, and the crushed dry fine coals are The fine coal is scattered and blown up, and flows out from the hot air exhaust pipe 15 together with the hot air.

Further, since the same hot air as that in the drying chamber 2 is supplied to the classifying chamber 3, the drying is performed in this step as well, to the target moisture value.

For this reason, it was found that even if the classifying chamber 3 was added, the captain would be approximately the same as when the conventional dryer was used.

Further, the discharge amount control valve 16 provided in the hot air discharge pipe 15 is adjusted when the superficial velocity of the classification chamber 3 is adjusted to change the classification point to change the classified particle size. That is, if the opening degree of the discharge control valve 16 is narrowed, for example, the hot air rising in the classifying chamber 3 becomes difficult to flow out from the hot air discharge pipe 15, and a part of the hot air flowing into the classifying chamber 3 is separated from the partition wall 9. Flows into the drying chamber 2 from between the upper end of the partition wall and the lower end of the partition wall 13. For this reason, the superficial velocity of the hot air rising in the classifying chamber 3 is reduced, and the particle size of the dry pulverized and fine coal particles flowing out from the hot air discharge pipe 15 is reduced by the reduced velocity of the superficial velocity.

On the other hand, since the flow velocity in the drying chamber 2 is lower than that in the classifying chamber 3 as described above, the hot air that flows into the drying chamber 2 from the classifying chamber 3 and rises has a low superficial velocity. As a result of the fine and fine grain coal that has flowed in with the hot air falling into the drying chamber 2, there is almost no change in the grain size of the fine grain coal that flows out from the hot air discharge pipe 14.

Further, as a dust collector, the bag filter BG introduces the fine / fine-grained coal flowing out from the drying chamber 2 and the classification chamber 3 along with the hot air through the hot air discharge pipes 14 and 15 and the hot air discharge main pipe 22, and separates and collects it.

Further, in the case where the amount of the raw coal C supplied to the drying chamber 2 varies, the layer thickness may be changed by adjusting the amount of the raw coal C supplied to the drying chamber 2. However, when this method is used, the amount of water entering the drying chamber 2 and the classifying chamber 3 fluctuates, the drying load changes, and the pressure loss in the drying chamber 2 and the classifying chamber 3 fluctuates and As a result of the change in the superficial velocity, complicated control is required. Therefore, the rotary feeder RB ₂ as a cutting device for cutting out the coarse coal in the classification chamber 3 is adjusted to the coal discharge passage 12, and the drying chamber is adjusted. The coking coal transport speed in each chamber 2, 3 is adjusted so that the layer thickness of the coking coal C in 2 and the classification chamber 3 becomes constant. As a result, only the drying load changes and the superficial velocity of the hot air does not change, so the controllability becomes good.

Therefore, the rotary feeder RB ₂ is adjusted according to the amount of the raw coal C dried and classified, and the layer thickness of the raw coal C in the drying chamber 2 and the classification chamber 3 is controlled to be constant.

However, since the drying load fluctuates as described above, it is necessary to adjust the hot air temperature to keep the moisture content of the fine / fine grained coal and coarse grained coal after classification. Therefore, drying of the raw coal C,
The valve 19 of the gas supply pipe 20 is adjusted by the drying load calculated from the classification processing amount and the amount of water contained, and the temperature of the hot air flowing into the drying chamber 2 and the classification chamber 3 is controlled.

Further, when the water content of the raw coal C supplied to the drying chamber 2 changes, the drying load in the drying chamber 2 and the classification chamber 3 also changes as described above, and thus the valve 19 of the gas supply pipe 20 is changed as described above. It is adjusted to maintain a constant water content after dry classification.

Further, like the means 2, the partition wall 13 can be moved up and down, and like the means 3, the louver 30 for adjusting the opening degree of the opening 31 provided in the middle of the partition wall 13 prevents the hot air rising in the classification chamber 3 from flowing. Fine adjustment of the superficial velocity is preferable because the classification accuracy can be stably maintained at a high level.

[Embodiment] An embodiment of the present invention will be described with reference to FIG.

In the figure, 1 is a hot air supply main, 2 is a drying room, 3 is a classification room, 4
Is a hot air supply chamber at the lower part of the drying chamber 2, 5 is a hot air supply branch pipe for supplying hot air to the hot air supply chamber 4, and a hot air flow rate adjusting valve 8a is interposed. 6 is a hot air supply chamber below the classification chamber 3, 7 is a hot air supply branch pipe for supplying hot air to the hot air supply chamber 6, and a hot air flow rate adjusting valve 8b is provided therebetween. Reference numeral 9 is a partition wall that separates the hot air supply chambers 4 and 6 and divides the amount of hot air supplied to each of the drying chamber 2 and the classification chamber 3. 10 is a dispersion plate, and the dispersion plate 10
Hot air is supplied to the drying chamber 2 and the classification chamber 3 through the opening 10a. Reference numeral 11 denotes a coal feeding channel, which is provided with a rotary feeder RB ₁ for supplying the raw coal C. 12 is a coal discharge passage,
A rotary feeder RB ₂ for discharging dried coarse coal is provided.

A partition wall 13 is provided vertically above the partition wall 9 to partition the upper part of the drying chamber 2 and the classifying chamber 3 to secure a necessary superficial velocity of hot air in the space above the classifying chamber 3.

14 is a hot air exhaust pipe communicating with the upper part of the drying chamber 2, 15 is a classification chamber 3
A hot air exhaust pipe communicating with the upper part, 16 is an exhaust gas adjusting valve provided in the hot air exhaust pipe 15, and 17 is a hot air supply main pipe 1 through a blower BR ₁ for a part of exhaust gas from a bag filter BG as a dust collector.
A circulating pipe for returning to the back, a combustor 18 for combusting the combustion gas MG to obtain hot air, a valve 19 provided in the gas supply pipe 20, a remaining exhaust gas from the bag filter BG via a blower BR _2. It is a chimney that diffuses into the atmosphere.

First, in Table 1, raw coal C having the water content and particle size shown in B.
Is fed into the drying chamber 2 from the coal feeding passage 11 through the rotary feeder RB ₁ . At this time, the air volume for fluidizing the raw coal C supplied to the drying chamber 2 and obtaining the flow velocity necessary for classification, and the required dry water content of the raw coal C (water content of the raw coal C to be supplied-after drying Target hot water amount), that is, hot air having a temperature according to the drying load is supplied from the hot air supply main pipe 1 to the hot air supply chambers 4 and 6 through the hot air supply branch pipes 5 and 7, and the hot air supply chambers 4 and 6 are further supplied. Is supplied to the drying chamber 2 and the classification chamber 3 through the opening 10a of the dispersion plate 10.

At this time, in the drying chamber 2, in order to prevent the pulverized coal in the raw material carbon C on the dispersion plate 10 from scattering as much as possible, the superficial velocity of the hot air rising in the drying chamber 2 is set to 0.3 m / sec. Adjust the adjusting valve 8a.

In this way, the raw coal C is fluidized by the hot air rising from the opening 10a of the dispersion plate 10 of the drying chamber 2, and the fine coals in the raw coal C are aggregated with each other or the fine coals are attached to the coarse coals. While unraveling (crushing), it is sequentially conveyed to the classification chamber 3 and dried.

In addition, a small amount of fine coal that has risen along with hot air during drying of the raw material carbon C in the drying chamber 2 flows out from the hot air discharge pipe 14.

The superficial velocity of the hot air flowing through the hot air supply branch pipe 7 and flowing from the opening 10a of the dispersion plate 10 and rising in the classification chamber 3 is 6 m / sec.
The opening of the flow rate adjusting valve 8b is adjusted so that

This hot air further fluidizes the raw material coal flowing from the drying chamber 2 and performs drying to the target water content while strengthening the crushing. Further, by discharging the fine / fine grain coal blown up by the hot air during fluidization together with the hot air from the discharge pipe 15, the coarse grain coal and the fine / fine grain coal are classified at a target classification point.

Then, the coarse coal flows into the coal discharge passage 12 and is cut out by the rotary feeder RB ₂ there. The water content and particle size of the cut coarse coal are shown in Table 1 (B).

Further, the fine / fine-grained coal is introduced into the bag filter BG together with the hot air through the hot-air discharge pipes 14 and 15 to be separated and collected. C).

A part of the hot air from which fine and fine coal is separated by this bag filter BG is circulated to the blower BR ₁ and the hot air supply main 1 on the outlet side of the combustor 18 via the circulation pipe 17, and the rest is the blower BR ₂
Through the chimney 21 to the atmosphere.

Next, the case of adjusting the classification point to adjust the classification ratio of the coarse-grained coal and the fine / fine-grained coal will be described.

Adjustment of this classification point can be achieved by adjusting the opening degree of the exhaust volume control valve 16, and the hot air exhaust main pipe 22
A capacitance type or correlation type powder flow rate measuring device 23 may be provided in the device, and the opening of the discharge amount adjusting valve 16 may be adjusted based on the measured value. The opening degree of the discharge control valve 16 may be adjusted based on the amount of coal and / or the amount of coarse coal cut out by the rotary feeder RB ₂ .

Further, when the water content of the raw material carbon C charged into the drying chamber 2 changes, the drying load in the drying chamber 2 and the classification chamber 3 increases, so the heat amount of the hot air supplied to the drying chamber 2 and the classification chamber 3 increases. Need to increase. Therefore, by adjusting the opening degree of the valve 19 provided in the gas supply pipe 20 to adjust the amount of gas supplied to the combustor 18, the temperature of the hot air flowing through the hot air supply main pipe 1 is adjusted. The opening degree of the valve 19 may be adjusted by providing a thermometer 24 in the hot air supply main pipe 1 and measuring the measured temperature value, or by measuring the amount of gas flowing into the combustor 18 with a flow meter (not shown). ), And the amount of gas may be adjusted to a desired hot air temperature.

At this time, the hot air rising in the dry classification chamber 3 contains the vapor evaporated from the raw coal C, but the vapor amount changes as the moisture content of the raw coal C changes. Since the superficial velocity of the hot air rising in the classifying chamber 3 changes due to the change in the amount of steam, it is necessary to adjust the opening degree of the exhaust amount adjusting valve 16.

Furthermore, when the throughput of the raw coal C changes, the rotary feeders RB ₁ and RB ₂ are adjusted to keep the layer thickness of the raw coal C in the drying chamber 2 and the classification chamber 3 constant, and the drying chamber 2 and the classification chamber Three
The transfer speed of the raw material coal C flowing through is adjusted. Then, since the drying load in the drying chamber 2 and the classification chamber 3 is increased in the same manner as described above, the opening degree of the valve 19 is adjusted to adjust the hot air temperature.

Further, as described above, the partition wall 13 was fixed to adjust the classification point, and the opening degree of only the discharge adjustment valve 16 was adjusted, but this is for coarse adjustment and for fine adjustment, the lower end of the partition wall 13 is used. It is preferable to control the position of the opening 31 by adjusting the position in the height direction or adjusting the opening of the louver 30 provided in the middle of the partition wall 13 as shown in FIG.

[Effect] According to the present invention described above, it is possible to dry coal to a target water content and to accurately classify it into a desired classified particle size. Further, it is not necessary to separately provide a fluidized bed dryer and a classifier, and further, it is not necessary to provide a closed transfer path between the classifier and the dryer, so that the facility cost can be significantly reduced. The effect of.

[Brief description of drawings]

FIG. 1 is a simplified sectional side view of the present invention, and FIG. 2 is a view showing another embodiment of a partition wall. 1 ... Hot air supply main pipe, 2 ... Drying chamber 3 ... Classification chamber, 4 ... Hot air supply chamber 5 ... Hot air supply branch pipe, 6 ... Hot air supply chamber 7 ... Hot air supply branch pipe, 8a ... Hot air flow rate control valve 8b ... Hot air flow rate Adjusting valve, 9 ... Partition wall 10 ... Dispersion plate, 10a ... Opening part 11 ... Coal supply channel, 12 ... Coal discharge channel 13 ... Partition wall, 14 ... Hot air exhaust pipe 15 ... Hot air exhaust pipe, 16 ... Exhaust volume adjusting valve 17 ... Circulation pipe, 18 ... Combustor 19 ... Valve, 20 ... Gas supply pipe 21 ... Chimney

Claims (3)

[Scope of utility model registration request] 1. A low-velocity hot air introduced from the lower side of a horizontally arranged dispersion plate conveys coal fed onto the dispersion plate while fluidizing it, and an exhaust pipe for discharging the hot air is connected to the upper part. By the hot air of high flow velocity introduced from below the fluidized drying chamber and the horizontally arranged dispersion plate, the coal fluidized and transported from the fluidized drying chamber to the dispersion plate is further fluidized and transported to the discharge path side while finely and finely flowing. Granulated coal was blown up to classify into the fine / fine grained coal and coarse grained coal, and a discharge pipe having an adjusting valve for adjusting the amount of hot air containing the blown up fine / fine grained coal was connected to the upper part. Wind power classification chamber, a partition wall that partitions the fluidized drying chamber and the wind power classification chamber leaving the coal passage, and introducing hot air that flows through the discharge pipe provided at the top of the fluidized drying chamber and the wind power classification chamber,
A dust collector for collecting fine and fine coal particles that accompanies the hot air, and a coarse particle coal cutting amount adjusting device provided in a discharge passage for discharging the coarse coal particles that are fluidly conveyed on the dispersion plate of the air classification chamber. A coal drying / classifying apparatus comprising: a cutting device and a hot air temperature controller that adjusts the temperature of hot air supplied from the bottom of the fluidized drying chamber and the air classification chamber. 2. The coal drying / classifying apparatus according to claim 1, wherein a partition wall for partitioning the fluidizing / drying chamber and the fluidizing / classifying chamber is provided so as to be vertically movable. 3. A coal drying / classifying apparatus, characterized in that an opening having an adjustable opening area is provided in the middle of a partition wall for partitioning the fluidizing drying chamber and the fluidizing / classifying chamber.