JP6972570B2 - Drying equipment and boiler system - Google Patents

Description

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

The following Patent Documents 1 to 3 disclose a drying device that dries an object (water-containing substance) such as low-grade coal by using a fluidized gas such as steam.

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

By the way, the housing of the drying device is made of steel, and a heat insulating material is provided on the outer surface in order to reduce heat dissipation. When starting such a drying device, the drying medium is put into the inside after sufficiently warming the inside, but in the inner wall of the drying device where heat dissipation is likely to occur, fluidized gas such as steam or drying is performed depending on the state of the drying medium. The water vapor released from the medium is likely to be condensed. The condensed liquid generated by such condensation becomes a factor that hinders the fluidization of the drying medium and hinders the stable operation of the drying device.

The present invention has been made in view of the above circumstances, and an object of the present invention is to suppress or prevent condensation.

In order to achieve the above object, in the present invention, as a first solution relating to the drying device, the drying device is a drying device for drying an object taken in a housing while being fluidized with a fluidized gas. A means of providing a heating means for heating the gas is adopted.

In the present invention, as a second solution relating to the drying apparatus, in the first solution, the heating means adopts a means of heating the fluidized gas by heating the side surface of the housing. ..

In the present invention, as a third solution according to the drying apparatus, in the first or second solution, the heating means includes a heat transfer tube provided in the housing.

In the present invention, as a fourth solution relating to the drying apparatus, in the third solution, the heat transfer tube extends in the vertical direction of the housing.

In the present invention, as a fifth solution according to the drying apparatus, in the third or fourth solution, a means in which a plurality of heat transfer tubes are provided between the inlet header tube and the outlet header tube is adopted. ..

In the present invention, as a solution relating to the boiler system, a drying device according to any one of the first to fifth solutions is provided, and the heating means takes in water vapor from the boiler body as a heat medium and the fluidized gas. The means of heating is adopted.

According to the present invention, since the heating means for heating the housing is provided, it is possible to suppress or prevent condensation.

It is a perspective view which shows the main part of the boiler system which concerns on one Embodiment of this invention, that is, the appearance of the drying apparatus. It is an X-ray arrow view in FIG. 1. It is a YY line arrow view in FIG. 1.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The drying device A according to the present embodiment is provided in a boiler system that burns fuel to generate steam as a product, and low-grade coal C (object to be dried) is dried and supplied to the boiler body as fuel. do. The low-grade coal C is, for example, brown coal having a relatively high water content in coal, and is a particulate water-containing substance crushed to a predetermined particle size range by a crusher provided in the previous step.

As shown in FIG. 1, such a drying device A is a fluidized bed type drying furnace having a rectangular shape (box shape) outer shape, and is a housing 1, a charcoal charging section 2, a gas intake section 3, and a pair. 1st heat medium header pipes 4A, 4B, 4 pairs of 2nd heat medium header pipes 5A to 5D, 5E to 5H, a charcoal discharge unit 6 and a gas exhaust unit 7 are provided.

Further, as shown in FIG. 3, the drying device A includes a plurality of gas injection units 8 communicating with the gas intake unit 3. Further, as shown in FIGS. 2 and 3, the drying device A includes a plurality of first heat transfer tubes 9 communicating with a pair of first heat medium header tubes 4A and 4B, and four pairs of second heat medium header tubes. A plurality of second heat transfer tubes 10A to 10D communicating with each of 5A to 5D and 5E to 5H are provided.

The housing 1 has a rectangular parallelepiped shape (box shape) made of metal, and has an internal volume according to the drying capacity. That is, the housing 1 is a box-shaped hollow body having four side surfaces (four side surfaces), one bottom surface, and one top surface, and houses the low-grade coal C inside. The internal space of such a housing 1 is a drying chamber in which the low-grade coal C is dried. Further, as will be described in detail later, in this housing 1, a plurality of second heat transfer tubes 10A to 10D are provided on four side surfaces at predetermined intervals.

The coal charging section 2 is a receiving opening for receiving the low-grade coal C supplied from the outside, and is provided at a relatively high position on one side surface of the housing 1. As shown in FIG. 1, the coal charging unit 2 has a charging port set upward, and guides the low-grade coal C supplied from above to the drying chamber. The low-grade coal C is taken in from such a coal charging unit 2 and housed in a drying chamber.

The gas intake portion 3 is provided near the bottom surface of one side surface of the housing 1. As shown in FIG. 1, the gas intake unit 3 is provided on the same surface as, for example, the charcoal charging unit 2 among the four side surfaces of the housing 1. Such a gas intake unit 3 is an opening for taking in the fluidized gas G for fluidizing the low-grade coal C in the drying chamber into the drying chamber. This fluidized gas G is, for example, steam, and is supplied from the boiler body.

As shown in the figure, the pair of first heat medium header tubes 4A and 4B are provided so as to horizontally face each other in the vertical direction at a predetermined distance in the middle of the side surfaces orthogonal to the installation surface of the charcoal charging section 2. There is. That is, the pair of first heat medium header tubes 4A and 4B are straight tubes extending in the horizontal direction in a state of facing each other in parallel at a predetermined distance on one side surface.

Of such a pair of first heat medium header tubes 4A and 4B, the upper first heat medium header tube 4A is an inlet that distributes the first heat medium N supplied from the outside to a plurality of first heat transfer tubes 9. The lower first heat medium header tube 4B is a header tube, and the first heat medium (used first heat medium Na) after heat exchange is recovered from the plurality of first heat transfer tubes 9 and discharged to the outside. It is an outlet header pipe. The first heat medium N is, for example, steam taken in from the boiler body as a heat medium.

The four pairs of second heat medium header tubes 5A to 5D and 5E to 5H are provided on the four side surfaces of the housing 1 so as to horizontally face each other with a predetermined distance in the vertical direction. That is, the pair of second heat medium header tubes 5A and 5E are opposed to each other in parallel at a predetermined distance in the vertical direction on the installation surface of the charcoal charging section 2, that is, they extend horizontally so as to sandwich the charcoal charging section 2. It is a straight pipe. The pair of second heat medium header tubes 5B and 5F face each other in parallel at a predetermined distance in the vertical direction on the installation surface of the pair of first heat medium header tubes 4A and 4B, that is, the pair of first heat medium headers. It is a straight pipe extending in the horizontal direction so as to sandwich the pipes 4A and 4B.

The pair of second heat medium header pipes 5C and 5G are in a state of being parallel to each other at a predetermined distance in the vertical direction on the side surface (installation surface) facing parallel to the installation surface of the charcoal charging section 2, that is, sandwiching the charcoal discharge section 6. It is a straight pipe that extends in the horizontal direction. Further, the pair of second heat medium header tubes 5D and 5H face each other in parallel at a predetermined distance in the vertical direction on the side surfaces (installation surfaces) facing parallel to the installation surfaces of the pair of first heat medium header tubes 4A and 4B. It is a straight pipe that extends horizontally in the state.

Of the four pairs of second heat medium header tubes 5A to 5D and 5E to 5H, the second heat medium header tubes 5A to 5D located on the upper side have a plurality of second heat mediums M supplied from the outside. The inlet header tubes distributed to the second heat transfer tubes 10A to 10D, and the second heat medium header tubes 5E to 5H located on the lower side are the second heat medium M (used second heat medium Ma) after heat exchange. Is an outlet header tube that collects heat from a plurality of second heat transfer tubes 10A to 10D and discharges the heat to the outside.

Of these four pairs of second heat medium header tubes 5A to 5D and 5E to 5H, the upper second heat medium header tubes 5A to 5D are provided at substantially the same height as shown in the figure, and are provided on the lower side. The second heat medium header tubes 5E to 5H are provided at substantially the same height as shown in the figure. The second heat medium N is, for example, steam taken in from the boiler body as a heat medium.

The charcoal discharge unit 6 is provided on a side surface (installation surface) parallel to the installation surface of the charcoal input unit 2, that is, in a state of being separated from the charcoal input unit 2. The charcoal discharge unit 6 is a discharge port for discharging dry low-grade coal, that is, dry low-grade coal Ca to the outside. As shown in FIG. 1, the charcoal discharge unit 6 has a discharge port facing downward, and the dry low-grade coal Ca is dropped downward.

The gas exhaust portion 7 is an opening provided on the upper surface of the housing 1. The gas exhaust unit 7 exhausts the fluidized gas, that is, the used fluidized gas Ga, which is injected from the gas injection unit 8 into the drying chamber and contributes to the fluidization of the low-grade coal C.

The gas injection unit 8 is an injection nozzle arranged two-dimensionally on the bottom surface of the housing 1 at predetermined intervals. The gas injection unit 8 injects the fluidized gas G toward the low-grade coal C located on the upper side to fluidize the low-grade coal C in the drying chamber. That is, in the drying chamber, the fluidized bed R of the low-grade coal C is formed by the fluidized gas G injected from the plurality of gas injection units 8.

The plurality of first heat transfer tubes 9 are metal tubes communicating with a pair of first heat medium header tubes 4A and 4B, and the first heat medium N supplied from one first heat medium header tube 4A is the other first heat transfer tube 9. 1 It circulates toward the heat medium header tube 4B. These plurality of first heat transfer tubes 9 exist in the fluidized bed R and heat the low-grade coal C by heat exchange with the low-grade coal C.

The plurality of second heat transfer tubes 10A to 10D are metal tubes communicating with each of the four pairs of second heat medium header tubes 5A to 5D and 5E to 5H, and are supplied from one of the second heat medium header tubes 5A to 5D. The second heat medium M flows toward the other second heat medium header pipes 5E to 5H. As shown in FIGS. 2 and 3, the plurality of second heat transfer tubes 10A to 10D are provided on the four side surfaces of the housing 1, respectively.

Of the plurality of second heat transfer tubes 10A to 10D, the second heat transfer tube 10A is a second heat transfer header tube 5A (2) provided on the installation surface of the charcoal charging section 2 among the four side surfaces of the housing 1. A plurality of them are provided between the inlet header tube) and the second heat medium header tube 5E (outlet header tube). Further, the second heat transfer tube 10B includes a second heat medium header tube 5B (inlet header tube) and a second heat medium header tube 5F (outlet header) provided on the installation surface of the pair of first heat medium header tubes 4A and 4B. Multiple pipes are provided between the pipes).

Further, a plurality of second heat transfer tubes 10C are provided between the second heat medium header tube 5C (inlet header tube) and the second heat medium header tube 5G (outlet header tube) provided on the installation surface of the charcoal discharge section 6. It is provided. Further, the second heat transfer tube 10D includes a second heat medium header tube 5D (inlet header tube) and a second heat medium header provided on the side surfaces parallel to the installation surfaces of the pair of first heat medium header tubes 4A and 4B. A plurality of pipes are provided between the pipe 5H (exit header pipe).

These plurality of second heat transfer tubes 10A to 10D extend in the vertical direction of the housing 1 between the upper second heat medium header tubes 5A to 5D and the lower second heat medium header tubes 5E to 5H. .. Further, the four side surfaces of the housing 1 provided with the plurality of second heat transfer tubes 10A to 10D are selected as locations where the fluidized gas G injected into the housing 1 is likely to condense. be.

In this way, the second heat transfer tubes 10A to 10D provided on the four side surfaces of the housing 1 and the second heat transfer tubes 10A to 10D are communicated with each other, and the second heat transfer tubes M are connected to the plurality of second heat transfer tubes 10A to 10D. 2nd heat medium header tubes 5A to 5H (outlet header tubes) for recovering the 2nd heat medium M from the 2nd heat medium header tubes 5A to 5D (inlet header tubes) and the plurality of 2nd heat transfer tubes 10A to 10D. Consists of the heating means in the present invention. That is, the second heat medium header tubes 5A to 5H and the second heat transfer tubes 10A to 10D in the present embodiment take in water vapor as a heat medium from the boiler main body and heat the fluidized gas G.

Next, the operation of the drying device A configured in this way will be described in detail.
In the drying apparatus A according to the present embodiment, the low-grade coal C continuously supplied from the outside is sequentially received by the charcoal charging unit 2 and subjected to a drying treatment, and the dry low-grade coal Ca obtained by the drying treatment is charcoal. It is sequentially discharged to the outside from the discharge unit 6.

That is, the low-grade coal C sequentially taken in from the coal charging unit 2 is continuously fluidized by sequentially injecting the fluidized gas G from the gas injection unit 8 in the drying chamber of the housing 1, forming the fluidized bed R. do. Then, the low-grade coal C is heated by heat exchange with a plurality of first heat transfer tubes 9 existing in the fluidized bed R. As a result, the water contained in the low-grade coal C is steamed, separated from the low-grade coal C, rises in the drying chamber, and is finally exhausted from the gas exhaust section 7 to the outside of the housing 1.

Then, the low-grade coal C in the drying chamber is gradually dried by being fluidized by the fluidized gas G and heated by the first heat transfer tube 8. Further, the low-grade coal C gradually moves from the vicinity of the coal input section 2 toward the coal discharge section 6, and is finally discharged to the outside from the coal discharge section 6 as dry low-grade coal Ca.

Here, in such a drying device A, the fluidized gas G is injected into the fluidized bed R from the plurality of gas injection units 8, but the fluidized gas G is injected into the vicinity of the four side surfaces (predetermined locations) of the housing 1. The gas G tends to condense because its four side surfaces (predetermined locations) are cooled by the outside air. In response to such circumstances, in the drying device A, a plurality of second heat transfer tubes 10A to 10D are provided on the four side surfaces (predetermined locations) of the housing 1, and the four side surfaces (predetermined locations) are the second heat transfer tubes. Since it is sufficiently heated by the second heat medium M flowing in the 10A to 10D, it is possible to suppress or prevent the above-mentioned condensation of the fluidized gas G.

Therefore, according to the drying apparatus A according to the present embodiment, it is possible to suppress or prevent the condensation of the fluidized gas G, so that the low-grade coal C in the fluidized bed R is caused by the condensed liquid of the fluidized gas G. It is possible to suppress or eliminate poor flow. As a result, according to the drying device A according to the present embodiment, it is possible to realize stable operation of the drying device A.

Further, in this drying device A, a plurality of second heat transfer tubes 10A to 10D are extended in the vertical direction of the housing 1 by facing the pair of second heat medium header tubes 5A to 5D and 5E to 5H in the vertical direction. Therefore, even if a situation occurs in which the second heat medium M supplied from the upper second heat medium header tubes 5A to 5D (inlet header tube) condenses in the second heat transfer tubes 10A to 10D, even if a situation occurs. This condensed water can be easily recovered in the lower second heat medium header tubes 5E to 5H (outlet header tubes) by the action of gravity.

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 heating means is configured by the second heat medium header tubes 5A to 5D, 5E to 5H and the second heat transfer tubes 10A to 10D, but the present invention is not limited thereto. That is, in the above embodiment, the four side surfaces of the housing 1 are heated by the second heat medium M, but another heating method may be adopted as the heating means. For example, an electric heater may be adopted instead of the second heat medium header tubes 5A to 5D, 5E to 5H and the second heat transfer tubes 10A to 10D.

Further, in the above embodiment, the second heat transfer tubes 10A to 10D are provided inside the housing 1, but the present invention is not limited to this. Instead of the housing 1 and the plurality of second heat transfer tubes 10A to 10D, for example, by interconnecting the peripheral surfaces of a plurality of heat transfer tubes arranged in parallel with each other, a housing (wall surface) having a function of a heating means can be provided. It may be configured. Further, in this case, instead of directly connecting the peripheral surfaces of the heat transfer tubes adjacent to each other, a member (connecting member) for connecting the heat transfer tubes may be inserted between the heat transfer tubes.

(2) In the above embodiment, a plurality of second heat transfer tubes 10A to 10D are provided with the four side surfaces of the housing 1 as predetermined locations, but the present invention is not limited thereto. A plurality of second heat transfer tubes 10A to 10D may be provided only on a part of the four side surfaces of the housing 1, for example, only the lower portion of the four side surfaces. That is, of the four side surfaces of the housing 1, only the region near the gas injection unit 8 that injects the fluidized gas G into the fluidized bed R may be selectively heated.

(3) In the above embodiment, the second heat medium M is circulated in the second heat transfer tubes 10A to 10D to heat the four side surfaces (predetermined locations), and this distribution is performed during the operation period of the drying device A. It may be performed at all times, but it may be performed only for a necessary period depending on the operating state of the drying device A, the ambient temperature, and the like. As this period, for example, a predetermined time can be considered from the start of operation of the drying device A.

(4) In the above embodiment, as shown in FIGS. 1 to 3, four pairs of second heat medium header tubes 5A to 5D and 5E to 5H are arranged on the outside of the four side surfaces of the housing 1, whereas the second heat medium header tubes 5A to 5D and 5E to 5H are arranged on the outside of the four side surfaces of the housing 1. A plurality of second heat transfer tubes 10A to 10D are arranged inside the four side surfaces of the housing 1. According to such a configuration, since the plurality of second heat transfer tubes 10A to 10D are arranged inside the four side surfaces of the housing 1, it is possible to efficiently suppress the condensation of the fluidized gas G.

However, if necessary, a plurality of second heat transfer tubes 10A to 10D may be arranged outside the four side surfaces of the housing 1. Further, four pairs of second heat medium header tubes 5A to 5D and 5E to 5H may also be arranged inside the four side surfaces of the housing 1 if necessary.

C Low-grade charcoal (object to be dried)
Ca Dry low-grade coal G Fluidized gas Ga Used fluidized gas N 1st heat medium M 2nd heat medium R Fluidized bed 1 Housing 2 Charcoal input part 3 Gas intake part 4A, 4B 1st heat medium header tube 5A ~ 5D 2nd heat medium header tube (inlet header tube)
5E-5H 2nd heat medium header tube (outlet header tube)
6 Charcoal discharge part 7 Gas exhaust part 8 Gas injection part 9 1st heat transfer tube 10A-10D 2nd heat transfer tube

Claims (5)

A drying device that dries an object taken into a housing while fluidizing it with fluidized gas.
A heating means for heating the fluidized gas is provided .
The heating means is provided with a plurality of heat medium tubes provided on the side surface of the housing at a predetermined distance in the vertical direction, and the fluidized gas is heated by heating the side surface. Device. The drying device according to claim 1, wherein the heating means includes a heat transfer tube provided in the housing. The drying device according to claim 2, wherein the heat transfer tube extends in the vertical direction of the housing. The drying device according to claim 2 or 3, wherein a plurality of the heat transfer tubes are provided between the inlet header tube and the outlet header tube. The drying apparatus according to any one of claims 1 to 4 is provided.
The heating means is a boiler system characterized in that water vapor is taken in from the boiler body as a heat medium to heat the fluidized gas.

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