JP3917872B2 - Soot blower for coal gasifier - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a soot blower that removes soot and dust in a coal gasifier, and more particularly to a soot blower for a coal gasifier that has an improved gas seal structure.
[0002]
[Prior art]
In general, a soot blower periodically removes dust deposited on a tube group in a boiler or a heat exchanger by spraying an injection medium such as steam to maintain and recover the heat transfer efficiency. 4 shows a pull-out type soot blower in which the lance pipe moves horizontally while rotating.
In the soot blower of FIG. 4, the lance pipe 2 is attached at its tip side to a seal box 26 fixed to the wall 25 of the boiler or heat exchanger 24, and the rear side is laterally placed in a casing 28 supported by a support frame 27. It is installed in a standing state.
[0003]
Further, a supply pipe 30 for supplying the ejection medium 4 into the lance pipe 2 through a valve 29 is fitted inside the lance pipe 2 so as to be airtight and slidable in the axial direction. The supplied injection medium 4 is injected toward the tube group 31 of the boiler or heat exchanger 24 from the nozzle 3 formed at the tip of the lance pipe 2.
The front end of the lance tube 2 is supported by a support roller 32, and the rear portion is supported by a guide roller 34 via a gear box 33 attached integrally with the lance tube 2.
[0004]
A pinion gear 35 is provided on the upper portion of the gear box 33 and meshes with a rack 36 attached to the upper wall of the casing 28. Therefore, when the rotation of the motor 37 is decelerated by the gear box 33 and transmitted to the pinion gear 35, the gear box 33 moves along the rack 36 with the lance pipe 2.
At the same time, the rotation of the motor 37 gives a rotation around the axis to the lance tube 2. Accordingly, the lance tube 2 moves horizontally while being rotated by the motor 37.
[0005]
Further, in order to prevent the gas in the furnace from leaking from the attachment portion of the lance pipe 2 to the boiler or the exchanger 24, a seal ring 38 is provided in the seal box 26, and the seal ring 38 is attached to the seal box 26 by a spring 39. While pressing against the inner wall, sealing air is introduced from the air supply pipe 40 into the sealing box 26 for sealing.
The pressure in the furnace of the boiler or heat exchanger 24 is generally several hundred mmAq, and the pressure of the sealing air introduced into the seal box 26 is usually set 100 to 150 mmAq higher than the pressure in the furnace. Has been.
[0006]
However, the seal air leaks into and out of the furnace through the gap between the seal ring 38 and the lance pipe 2, and when the inner diameter of the seal ring 38 increases over time due to wear, the internal pressure of the seal box 26 decreases and the interior of the furnace completely disappears. It will not be possible to prevent gas leakage.
By the way, the coal gasification furnace has a high pressure of 2.0 MPa or more in the furnace, and since the gas properties are also highly toxic with CO gas as the main component, leakage into the atmosphere is absolutely Therefore, there is a problem that the conventional seal structure cannot be adopted.
[0007]
[Problems to be solved by the invention]
The present invention eliminates the drawbacks of the seal structure in the soot blower used in the conventional boilers and heat exchangers as described above, and is used for a novel coal gasifier having a seal structure that can withstand high pressure in the furnace. The challenge is to provide a sootblower.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention is a soot blower that removes soot and dust in a coal gasification furnace by injecting an injection medium from a nozzle formed at the tip of a lance pipe, and rotating and horizontally moving the lance pipe A seal box in which a segment seal constructed by incorporating a plurality of seal rings, a gland packing that prevents gas leakage, and a bearing that supports the lance pipe are integrally provided in a part of a casing that is freely supported. A soot blower for a coal gasifier having the above structure is provided.
[0009]
In the soot blower for a coal gasifier according to the present invention, a segment seal constructed by incorporating a plurality of seal rings, a gland packing for preventing gas leakage, and a bearing for supporting the lance pipe are integrally coupled. Since the seal box is provided, even if the furnace gas leaks into the seal box through the surface of the lance tube, the high-pressure seal gas in the segment seal prevents leakage into the seal box. Even if the gas in the furnace leaks to the position of the gland packing, the pressure is reduced by the segment seal, and leakage to the outside can be completely prevented by the gland packing. Leakage to is prevented.
[0010]
In the soot blower for a coal gasification furnace according to the present invention, a casing that supports a lance pipe so as to be rotatable and horizontally movable is constituted by a plurality of casings that are shut off from outside air and fastened in an airtight manner, and the casing is gasified with coal. It is preferable that the casing communicates with the inside of the furnace and has a structure that allows easy assembly of the casing that is shut off from the outside air.
[0011]
In the soot blower for a coal gasifier according to the present invention, as the segment seal constituting the above-mentioned seal box, the number of seal rings incorporated in one section is three, and the sealing effect is exhibited while suppressing the manufacturing cost. It is practically preferable to do this.
[0012]
Further, in the soot blower for a coal gasifier according to the present invention, it is preferable to have a structure that prevents gas leakage by preventing the split lines of the ring pieces of the seal ring constituting the segment seal from overlapping each other. In the soot blower for a coal gasification furnace of the present invention, it is preferable that the surface of the lance pipe is calorized to prevent wear due to sliding.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described based on a soot blower for a coal gasifier according to the embodiment shown in FIG.
In FIG. 1, 1 is a coal gasification furnace, 2 is a lance pipe, and an injection medium 4 is injected into the coal gasification furnace 1 from a nozzle 3 formed at the tip of the lance pipe 2, and is supplied to a tube group in the gas furnace. Remove deposited dust. The lance tube 2 is supported so as to be movable in the axial direction while rotating around the axis, but the means thereof may be of the conventional structure shown in FIG. .
[0014]
Reference numeral 5 denotes a segment seal, which is divided into front and rear portions in the axial direction with reference to the seal gas injection position from the seal gas supply pipe 7.
The segment seal 5 has a tip on the side of the coal gasification furnace 1 leading to an opening-time decompression pipe 9 that releases the gas in the system at the time of opening, and a side opposite to the coal gasification furnace 1 through a casing 13 described later. It leads to the seal gas discharge pipe 8. These segment seals 5 are shielded from the outside air and stored in the casing 12.
[0015]
Reference numeral 6 denotes a gland packing which is stored in a casing 13 having a seal gas discharge pipe 8 while being cut off from outside air. Reference numerals 10 and 11 denote bearings that support the lance tube 2 so as to be rotatable and horizontally movable. A casing 12 for housing the segment seal 5 and a casing 13 for housing the gland packing 6 are hermetically fastened by a flange and integrated to form a seal box S. Further, the casing 12 is hermetically fastened with another casing (shown by phantom lines) that supports the lance tube 2 so as to be rotatable and horizontally movable, and communicates with the coal gasification furnace 1.
[0016]
Next, the details of the segment seal 5 and the gland packing 6 are shown in FIGS. 2 and 3, which will be described. First, in FIG. 2 showing the segment seal 5, 15, 16, and 17 are seal rings, each of which is divided into a plurality of ring pieces in the circumferential direction so as to abut on the periphery of the lance tube 2, and the circumferential surface thereof is a garter spring. In a state of being fastened in a disk shape at 18, it is accommodated in a plurality of seal chambers defined by the seal case 14, and each side spring 19 is pressed against the seal case 14 and attached.
[0017]
The seal rings 15, 16, and 17 are changed in the number and shape of the seal ring pieces so that the split lines of the ring pieces in adjacent seal rings do not overlap in order to reduce leakage of seal gas downstream. The position is shifted. In addition, the number of seal rings functions as long as it is two or more, but three is desirable from the standpoint of sealing effect and manufacturing cost. The material of the seal rings 15, 16, and 17 constituting the segment seal 5 is preferably carbon, polyimide resin, or fluororesin, and is appropriately selected depending on the use environment.
[0018]
Next, in FIG. 3 showing the gland packing 6, the gland packing 6 forms a seal part by sandwiching the foil 21 with the carbon fiber 20, and further sandwiches both ends of the seal part with the bearings 22 and presses them with the packing presser 23 so as to be airtight. It is composed.
Since the bearings 10, 11 and 22 used in the seal box S are required to have high airtightness to the gland packing, bearings made of sintered metal containing graphite in consideration of wear resistance. Is preferred.
[0019]
Further, the surface of the lance tube 2 needs to be hardened in order to prevent wear due to sliding with the seal rings 15, 16, 17 and the like. In view of the manufacturing cost, the calorizing treatment is most preferable.
[0020]
In the soot blower for the coal gasification furnace shown in FIGS. 1 to 3 described above, the seal gas, for example, nitrogen gas is supplied from the seal gas supply pipe 7 at a pressure equal to or higher than the internal pressure of the coal gasification furnace 1 in the casings 12 and 13. When supplied into the constructed seal box S, it flows as shown by the arrow, and the seal gas supply unit always fills the coal gasification furnace 1 side with a seal gas equal to or higher than the internal pressure of the coal gasification furnace 1, and the opposite side Seal gas flows from the gaps between the seal rings 15, 16, and 17 toward the gland packing 6, but the amount is small and the high pressure in the segment seal 5 can be maintained.
[0021]
Therefore, even if the in-furnace gas leaks along the surface of the lance tube 2, leakage into the seal box S can be prevented by the high pressure of the segment seal 5. Even if the gas in the furnace leaks to the position of the gland packing 6, the pressure is reduced by the segment seal 5, so that leakage is prevented by the gland packing 6 and discharged by the discharge means of the seal gas discharge pipe 8. There is no leakage outside the box S.
By using the soot blower employing the seal box S configured as described above, the removal of the coal gasification furnace 1 operating at high pressure can be performed safely.
[0022]
Although the present invention has been specifically described above based on the embodiment, the present invention is not limited to this embodiment, and various changes and modifications may be added within the scope of this patent indicated in the claims. Needless to say.
For example, the number of segment seals 5 and the number of seal rings 15, 16, 17 may be arbitrarily selected, or the side springs 19 may be stopped and pressed against the seal case 14 by seal gas pressure. The configuration may also be appropriate.
[0023]
【The invention's effect】
As specifically described above, the present invention is a soot blower that removes soot and dust in a coal gasification furnace by injecting an injection medium from a nozzle formed at the tip of the lance pipe, and rotating the lance pipe. A seal box in which a segment seal in which a plurality of seal rings are incorporated in a part of a casing that is movably supported horizontally, a gland packing that prevents gas leakage, and a bearing that supports the lance pipe are integrally coupled. A soot blower for a coal gasification furnace having the above structure is provided.
[0024]
In the soot blower for a coal gasification furnace of the present invention provided with a seal box constituted by integrally connecting a segment seal, a gland packing, and a bearing configured as described above, a high pressure is transmitted along the surface of the lance pipe. Even if the gas inside the furnace leaks, the high-pressure seal gas in the segment seal prevents leakage into the seal box, and even if the gas inside the furnace leaks to the position of the gland packing, Completely preventing the leakage out of the seal box.
[0025]
In the soot blower for a coal gasifier according to the present invention, the casing is constituted by a plurality of casings that are shut off from outside air and fastened in an airtight manner, and the casing is configured to communicate with the inside of the coal gasifier, It is easy to assemble a casing that is shielded from outside air.
[0026]
Further, in the soot blower for a coal gasification furnace according to the present invention, in which the dividing lines of the ring pieces of the seal ring constituting the segment seal do not overlap each other, the gas leakage is surely prevented.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a schematic structure of an integrated seal box in a soot blower for a coal gasifier according to an embodiment of the present invention.
2 is a longitudinal sectional view showing the structure of a segment seal that constitutes the seal box in FIG. 1. FIG.
3 is a longitudinal sectional view showing a structure of a gland packing constituting the seal box in FIG.
FIG. 4 is a longitudinal sectional view showing the structure of a conventional coal gasifier soot blower.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Coal gasification furnace 2 Lance pipe | tube 3 Nozzle 4 Injection medium 5 Segment seal 6 Gland packing 7 Seal gas supply pipe 8 Seal gas discharge pipe 9 Opening pressure release pipe 10 Bearing 11 Bearing 12 Casing 13 Casing 14 Seal case 15 Seal ring 16 Seal ring 17 Seal ring 18 Garter spring 19 Side spring 20 Carbon fiber 21 Grafoil 22 Bearing 23 Packing retainer 24 Boiler or heat exchanger 25 Wall 26 Seal box 27 Support frame 28 Casing 29 Valve 30 Supply pipe 31 Tube group 32 Support roller 33 Gear Box 34 Guide roller 35 Pinion gear 36 Rack 37 Motor 38 Seal ring 39 Spring 40 Air supply pipe S Seal box

Claims (5)

A soot blower for removing dust in a coal gasification furnace by injecting an injection medium from a nozzle formed at the tip of a lance pipe, and a plurality of parts on a part of a casing that supports the lance pipe in a rotatable and horizontally movable manner. A soot blower for a coal gasification furnace comprising a seal box in which a segment seal constructed by incorporating a single seal ring, a gland packing for preventing gas leakage, and a bearing for supporting the lance pipe are integrally coupled. . The soot blower for a coal gasifier according to claim 1, wherein the casing is constituted by a plurality of casings that are shut off from outside air and fastened in an airtight manner, and the casing communicates with the coal gasifier. Soot blower for coal gasifier. The soot blower for a coal gasifier according to claim 1, wherein the number of seal rings incorporated in one section of the segment seal is three. The soot blower for a coal gasifier according to claim 3, wherein the seal ring is attached so that the dividing lines of the ring pieces do not overlap each other. The soot blower for a coal gasifier according to claim 1, wherein the surface of the lance pipe is calorized.

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