JP6852418B2 - Drying equipment and drying system - Google Patents

Description

The present invention relates to a drying device and a drying system.

The following Patent Documents 1 to 3 disclose a drying device that dries an object (hydrous) such as low-grade coal by using a fluidized gas such as water vapor while fluidizing it.

Japanese Unexamined Patent Publication No. 2014-181839 Japanese Unexamined Patent Publication No. 2014-112020 Japanese Unexamined Patent Publication No. 2012-241995

By the way, when low-grade coal such as lignite is dried using the above-mentioned drying apparatus, the low-grade coal is put into the drying apparatus in a state of being crushed by a crusher provided in the previous stage. This crushed low-grade coal has a property that the particle size is distributed in a relatively wide range. When drying such low-grade coal with a wide range of particle sizes using the above-mentioned drying device as it is, for example, when the flow rate of the fluidized gas is set corresponding to the average particle size of the low-grade coal, the grains of the low-grade coal Due to the wide distribution of diameters, low-grade coal, which has a diameter significantly smaller than the average particle size, rides on the stream of fluidized gas and is immediately discharged to the outside of the drying device with almost no drying, and the average particle size. The low-grade coal, which has a much larger diameter than that, does not fluidize and stays at the bottom of the drying device where the air diffuser or the like is installed.

That is, with a conventional drying device, it is difficult to recover low-grade coal whose diameter is significantly smaller than the average particle size as fuel from the original recovery port, and the small diameter is recovered by particle filtration equipment such as a bag filter. Low grade charcoal is difficult to dry sufficiently. Further, in the conventional drying device, low-grade coal having a diameter significantly larger than the average particle size does not flow and stays in the drying device. Discharge equipment such as a collection port and a valve is required.

The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the dryness of low-grade coal.

In order to achieve the above object, in the present invention, as a first solution relating to the drying device, a drying device that dries low-grade coal while fluidizing it by using a predetermined fluidized gas, wherein the low grade coal is dried. A plurality of charcoal inlets that receive high-grade coal, a partition plate that sets a plurality of fluidized beds corresponding to the charcoal inlet by partitioning the internal space corresponding to the charcoal inlet, and a plurality of fluidized gases. A plurality of gas injection units individually injected into the fluidized bed, a heating unit provided in the plurality of fluidized beds to heat the fluidized bed, and a charcoal discharge unit provided apart from the charcoal input unit. When,
A means is adopted in which a gas exhaust unit provided apart from the gas injection unit is provided.

In the present invention, as a second solution relating to the drying apparatus, in the first solution, the partition plate selectively partitions the lower part of the internal space.

In the present invention, as a third solution according to the drying apparatus, in the first or second solution, the heating portion heats a plurality of the fluidized beds by extending through the partition plate. Adopt the means that it is a heat transfer tube.

In the present invention, as a fourth solution according to the drying apparatus, in any of the first to third solutions, the low-grade coal having a different particle size is supplied to the plurality of coal charging portions. Adopt the means of being done.

In the present invention, as a means for solving the drying system, any of the above-mentioned first to fourth drying devices and a drying device provided in front of the drying device are provided, and the low-grade coal is classified into a plurality of the charcoal charging portions. A means of providing a classification device for supplying each of them is adopted.

According to the present invention, it is possible to improve the dryness of low-grade coal.

It is a block diagram which shows the functional structure of the drying system which concerns on one Embodiment of this invention. It is a perspective view which shows the structure of the drying apparatus which concerns on one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The drying system according to the present embodiment is provided in a boiler system that burns fuel to generate steam as a deliverable, and is a component of a fuel supply system that supplies low-grade coal X to the boiler body as fuel. This drying system includes a classification device 1 and a drying device 2 as shown in FIG.

The classification device 1 is provided in front of the drying device 2, and is a device that classifies the granular low-grade coal X into three groups and individually supplies the granular low-grade coal X to the drying device 2. This classification device 1 classifies low-grade coal X into small-diameter coal X1, medium-diameter coal X2, and large-diameter coal X3 according to the size of the particle size, and these small-diameter coal X1, medium-diameter coal X2, and large-diameter coal X3. Output individually to the drying device 2.

The low-grade coal X is, for example, brown coal having a relatively high water content in coal, and is particles crushed in a particle size range of, for example, 0.001 to 2 mm by a crusher provided in the previous step. The classification device 1 uses low-grade coal X having such properties as, for example, a small-diameter coal X1 having a particle size range of 0.001 to 0.1 and a medium-diameter coal X2 having a particle size range of 0.1 to 0.5. Further, it is classified into a large-diameter coal X3 having a particle size range of 0.5 to 2.0.

The drying device 2 is a device that individually receives the small-diameter coal X1, the medium-diameter coal X2, and the large-diameter coal X3 and individually dries them. In this drying device 2, the small-diameter dry coal X1a obtained by drying the small-diameter coal X1, the medium-diameter dry coal X2a obtained by drying the medium-diameter coal X2, and the large-diameter dry coal X3 obtained by drying the large-diameter coal X3. X3a is discharged individually.

Subsequently, the detailed configuration of the drying device 2 will be described with reference to FIG. This drying device 2 is a fluidized bed type drying furnace formed in a rectangular parallelepiped shape (box shape) as shown, and is a low-grade coal by using a fluidized gas G and a heat medium N taken in from the outside. The small-diameter coal X1, the medium-diameter coal X2, and the large-diameter coal X3 are individually fluidized and dried. Such a drying device 2 includes a housing 3, three charcoal inlet portions 4a to 4c, two partition plates 5a, 5b, three gas injection portions 6a to 6c, a heat transfer tube 7, and three charcoal discharge portions 8a to 8c. And a gas exhaust unit 9.

The housing 3 has a rectangular parallelepiped shape (box shape) made of metal, and has an internal volume according to the drying capacity. The three charcoal charging portions 4a to 4c are receiving portions for receiving the small-diameter coal X1, the medium-diameter coal X2, and the large-diameter coal X3 having different particle size ranges from the classification device 1, and are the receiving portions on the upper surface of the housing 3. It is provided in the vicinity of one side at a predetermined interval along the one side. Of these three charcoal charging sections 4a to 4c, the charcoal charging section 4a is a receiving section for receiving the small-diameter coal X1, the charcoal charging section 4b is a receiving section for receiving the medium-diameter coal X2, and the charcoal charging section 4c. Is a receiving unit for receiving the large-diameter coal X3.

The two partition plates 5a and 5b are metal plates (flat plates) that partition the lower space in the housing 3 into three so as to correspond to the three charcoal charging portions 4a to 4c. These two partition plates 5a and 5b set three fluidized beds Ra to Rc corresponding to the three charcoal charging portions 4a to 4c by partitioning the lower part of the internal space of the housing 3 into three. That is, the two partition plates 5a and 5b selectively partition only the lower portion of the internal space of the housing 3 into three regions.

Of these three fluidized beds Ra to Rc, the fluidized bed Ra corresponds to the coal charging section 4a and is a region in which the small-diameter coal X1 dropped from the coal charging section 4a flows. The fluidized bed Rb corresponds to the coal charging section 4b, and is a region in which the medium-diameter coal X2 dropped from the coal charging section 4b flows. Further, the fluidized bed Rc corresponds to the coal charging section 4c, and is a region in which the large-diameter coal X3 dropped from the coal charging section 4c flows.

The three gas injection units 6a to 6c are provided directly below the fluidized beds Ra to Rc corresponding to the three fluidized beds Ra to Rc, and the fluidized gas G is supplied to each of the fluidized beds Ra to Rc. Inject individually. That is, of these three gas injection units 6a to 6c, the gas injection unit 6a is provided directly below the fluidized bed Ra and ejects the fluidized gas G toward the fluidized bed Ra located above. The gas injection unit 6b is provided directly below the fluidized bed Rb, and ejects the fluidized gas G toward the fluidized bed Rb located above the fluidized bed Rb. The gas injection unit 6c is provided directly below the fluidized bed Rc, and ejects the fluidized gas G toward the fluidized bed Rc located above the fluidized bed Rc.

Here, the flow rate of the fluidized gas G injected from the gas injection unit 6a toward the fluidized bed Ra is optimally set with respect to the particle size range of the small-diameter coal X1 forming the fluidized bed Ra. That is, the flow rate of the fluidized gas G in the gas injection unit 6a is set so that the small-diameter coal X1 in the fluidized bed Ra does not scatter and is sufficiently dried.

Further, the flow rate of the fluidized gas G injected from the gas injection unit 6b toward the fluidized bed Rb is optimally set with respect to the particle size range of the medium-diameter coal X2 forming the fluidized bed Rb. That is, the flow rate of the fluidized gas G in the gas injection unit 6b is set so that the medium-diameter coal X2 of the fluidized bed Rb does not scatter and is sufficiently dried.

Further, the flow rate of the fluidized gas G injected from the gas injection unit 6c toward the fluidized bed Rc is optimally set with respect to the particle size range of the large-diameter coal X3 forming the fluidized bed Rc. That is, the flow rate of the fluidized gas G in the gas injection unit 6c is set so that the large-diameter coal X3 of the fluidized bed Rc does not scatter and is sufficiently dried. The fluidized gas G injected by the three gas injection units 6a to 6c into the fluidized beds Ra to Rc is, for example, water vapor supplied from the boiler body.

The heat transfer tube 7 is a tubular member extending so as to straddle the three fluidized beds Ra to Rc in the lower space inside the housing 3, that is, to penetrate the two partition plates 5a and 5b. The heat transfer tube 7 evenly heats the three fluidized beds Ra to Rc by circulating the heat medium N supplied from the outside to the inside. The heat medium N is, for example, steam supplied from the boiler body. Such a heat transfer tube 7 corresponds to a heating portion in the present invention.

The three charcoal discharge portions 8a to 8c are provided on the side surfaces of the fluidized beds Ra to Rc in a state of being separated from directly below the three charcoal input portions 4a to 4c on the side surface of the housing 3. In the three fluidized beds Ra to Rc, the distance from directly below the three coal input portions 4a to 4c to the three coal discharge portions 8a to 8c is such that the small diameter coal X1, the medium diameter coal X2 and the large diameter coal X3 are flowing. It is a drying distance that becomes a small-diameter dry coal X1a, a medium-diameter dry coal X2a, and a large-diameter dry coal X3a by moving.

Of these three coal discharge units 8a to 8c, the coal discharge unit 8a is provided corresponding to the fluidized bed Ra, and the small diameter dry coal X1a dried at a drying distance is discharged to the outside. The charcoal discharge unit 8b is provided corresponding to the fluidized bed Rb, and discharges the medium-diameter dry coal X2a from which the medium-diameter coal X2 has been dried at a drying distance to the outside. Further, the charcoal discharge unit 8c is provided corresponding to the fluidized bed Rc, and discharges the large-diameter dry coal X3a obtained by drying the large-diameter coal X3 at a drying distance to the outside.

The gas exhaust unit 9 is provided on the upper surface of the housing 3, that is, above the three fluidized beds Ra to Rc so as to be separated from the three gas injection units 6a to 6c, and is injected into the three fluidized beds Ra to Rc. The fluidized gas G is exhausted to the outside.

Next, the operation of the drying system configured as described above, particularly the drying device 2, will be described in detail.

In the drying system according to the present embodiment, the classification device 1 classifies the low-grade coal X into the small-diameter coal X1, the medium-diameter coal X2, and the large-diameter coal X3, and individually supplies the low-grade coal X to the drying device 2. That is, the classification device 1 uses low-grade coal X (raw material) continuously supplied from the outside as a small-diameter coal X1 having a relatively small particle size range and a medium diameter medium diameter in a medium particle size range according to the size of the particle size. It is continuously classified into charcoal X2 and large diameter charcoal X3 having a relatively large particle size range. Then, the classification device 1 continuously and sequentially supplies the small-diameter coal X1, the medium-diameter coal X2, and the large-diameter coal X3 to the drying device 2 through individual supply routes.

In contrast to such a classifying device 1, the drying device 2 uses a fluidized gas G sequentially taken in from the outside and a heat medium N sequentially taken in from the outside, so that the drying device 2 has a small diameter individually sequentially received from the classifying device 1. The charcoal X1, the medium diameter charcoal X2, and the large diameter charcoal X3 are individually and sequentially dried. The drying device 2 is obtained by drying the small-diameter dry charcoal X1a obtained by drying the small-diameter charcoal X1, the medium-diameter dry charcoal X2a obtained by drying the medium-diameter charcoal X2, and the large-diameter charcoal X3. The large-diameter dry coal X3a is individually discharged in sequence.

Here, in the drying apparatus 2, the small-diameter coal X1, the medium-diameter coal X2, and the large-diameter coal X3 are continuously dried as follows. That is, the small-diameter coal X1 is sequentially taken into the housing 3 from the coal charging portion 4a and sequentially supplied to the fluidized bed Ra (one end portion of the fluidized bed Ra) directly below. Then, the small-diameter coal X1 is fluidized by the fluidized gas G sequentially supplied from below by the gas injection unit 6a, and is fluidized from one end of the fluidized bed Ra to the coal discharge portion 8a, that is, the other end of the fluidized bed Ra. Move toward each other.

When the small-diameter coal X1 moves from one end to the other end of the fluidized bed Ra, the fluidized gas is heated by the heat transfer tube 7 through which the heat medium N flows inside and is sprayed from the gas injection section 6a. Due to the flow by G, the contained water gradually evaporates and dries. Then, the small-diameter charcoal X1 becomes the small-diameter dry charcoal X1a as a result of such drying, and is discharged to the outside from the charcoal discharge unit 8a.

On the other hand, the medium-diameter coal X2 is sequentially taken into the housing 1 from the coal charging section 4b and sequentially supplied to the fluidized bed Rb (one end of the fluidized bed Rb) immediately below. The medium-diameter coal X2 is fluidized by the fluidized gas G sequentially supplied from below by the gas injection unit 6b, and is fluidized from one end of the fluidized bed Rb, that is, the other end of the fluidized bed 8b, that is, the fluidized bed Rb. Move in sequence towards.

Then, when the medium-diameter coal X2 moves from one end to the other end of the fluidized bed Rb, it is heated by the heat transfer tube 7 through which the heat medium N flows inside and fluidized by being sprayed from the gas injection section 6b. Due to the flow by the gas G, the contained water gradually evaporates and dries. Then, the medium-diameter charcoal X2 becomes the medium-diameter dry charcoal X2a as a result of such drying, and is discharged to the outside from the charcoal discharge unit 8b.

On the other hand, the large-diameter coal X3 is sequentially taken into the housing 1 from the coal charging section 4c and sequentially supplied to the fluidized bed Rc (one end of the fluidized bed Rc) directly below. The large-diameter coal X3 is fluidized by the fluidized gas G sequentially supplied from below by the gas injection unit 6c, and is fluidized from one end of the fluidized bed Rc, that is, the other end of the fluidized bed 8c, that is, the fluidized bed Rc. Move in sequence towards.

Then, when the large-diameter coal X3 moves from one end to the other end of the fluidized bed Rc, it is heated by the heat transfer tube 7 through which the heat medium N flows inside and fluidized by being sprayed from the gas injection section 6c. Due to the flow by the gas G, the contained water gradually evaporates and dries. Then, the large-diameter charcoal X3 becomes the large-diameter dry charcoal X3a as a result of such drying, and is discharged to the outside from the charcoal discharge unit 8c.

On the other hand, the fluidized gas G injected from the gas injection unit 6a into the fluidized bed Ra rises upward from the fluidized bed Ra together with the water vapor separated from the small-diameter coal X1 and is exhausted from the gas exhaust unit 9 to the outside of the housing 1. Will be done. Further, the fluidized gas G injected from the gas injection unit 6b into the fluidized bed Rb rises upward from the fluidized bed Rb together with the water vapor separated from the medium-diameter coal X2, and from the gas exhaust unit 9 to the outside of the housing 1. It is exhausted. Further, the fluidized gas G injected from the gas injection unit 6c into the fluidized bed Rc rises upward from the fluidized bed Rc together with the water vapor separated from the large-diameter coal X3, and goes from the gas exhaust unit 9 to the outside of the housing 1. It is exhausted.

That is, the water vapor and the fluidized gas G separated from the fluidized bed Ra, the water vapor and the fluidized gas G separated from the fluidized bed Rb, and the water vapor and the fluidized gas G separated from the fluidized bed Rc flow in three in the housing 3. It merges above the layers Ra to Rc and is exhausted from the gas exhaust section 9 as a merged gas.

According to this embodiment, the small-diameter coal X1, the medium-diameter coal X2, and the large-diameter coal X3, in which the low-grade coal X is classified into three by the classification device 1, are individually dried in the three fluidized beds Ra to Rc. Therefore, it is possible to improve the drying property of the low-grade coal X.

Further, according to the present embodiment, since the two partition plates 5a and 5b selectively partition only the lower part of the housing 3 into three regions, the two fluidized beds Ra to Rc are above the three fluidized beds Ra to Rc. The separated water vapor and fluidized gas can be combined, and thus can be exhausted to the outside from the independent gas exhaust unit 9.

Further, according to the present embodiment, since the fluidized beds Ra to Rc are heated by the heat transfer tubes 7 provided so as to extend through the two partition plates 5a and 5b, the fluidized beds Ra to Rc are respectively. Can be heated uniformly. That is, according to the present embodiment, it is possible to suppress or eliminate heating unevenness in each of the fluidized beds Ra to Rc.

The present invention is not limited to the above embodiment, and for example, the following modifications can be considered.
(1) In the above embodiment, the low-grade coal X is classified into a small-diameter coal X1, a medium-diameter coal X2, and a large-diameter coal X3 and individually dried, but the present invention is not limited thereto. The low-grade coal X may be classified into two or four or more, that is, a plurality of coals, and individually dried. That is, a plurality of coal input sections, partition plates, gas injection sections, coal discharge sections, and fluidized beds constituting the drying device are provided according to the number of classifications of the low-grade coal X.

(2) In the above embodiment, the charcoal charging portions 4a to 4c are provided on the upper surface of the housing 3, but the present invention is not limited to this. For example, the charcoal charging portions 4a to 4c may be provided on the side surface of the housing 3.

(3) In the above embodiment, the heat transfer tube 7 is adopted as the heating unit, but the present invention is not limited to this. Further, the charcoal discharge portions 8a to 8c are not limited to the height of the side surface, and may be provided on the bottom surface or the bottom surface of the side surface.

X Low-grade coal X1 Small-diameter coal X2 Medium-diameter coal X3 Large-diameter coal X1a Small-diameter dry coal X2a Medium-diameter dry coal X3a Large-diameter dry coal Ra to Rc Fluidized bed 1 Classification device 2 Drying device 3 Housing 4a to 4c Charcoal input part 5a 5b Partition plate 6a to 6c Gas injection part 7 Heat transfer tube 8a to 8c Charcoal discharge part 9 Gas exhaust part

Claims (5)

A drying device that dries low-grade coal while fluidizing it by using a predetermined fluidized gas.
A plurality of coal input units that accept the low-grade coal, and
A partition plate for setting a plurality of fluidized beds corresponding to the charcoal charging portion by partitioning the internal space corresponding to the charcoal charging portion.
A plurality of gas injection units that individually inject the fluidized gas into the plurality of fluidized beds,
A heating unit provided in the plurality of fluidized beds to heat the fluidized bed,
A plurality of coal discharge parts provided for each fluidized bed apart from the coal input part,
A drying apparatus characterized in that a gas exhaust unit provided independently in the upper central portion of the charcoal discharge unit is provided apart from the gas injection unit. The drying apparatus according to claim 1, wherein the partition plate selectively partitions the lower portion of the internal space. The drying apparatus according to claim 1 or 2, wherein the heating unit is a heat transfer tube that heats a plurality of the fluidized beds by extending through the partition plate. The drying apparatus according to any one of claims 1 to 3, wherein the low-grade coal having a different particle size is supplied to each of the plurality of coal charging units. The drying apparatus according to any one of claims 1 to 4,
The drying device is provided in front of the drying system, characterized in that said and a plurality of the coal charged respectively supplied classifier in part device and classifying the low-grade coal.

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