JP6583004B2 - Deposit removal device - Google Patents

Description

  The present invention relates to a deposit removing device that effectively removes sticky deposits attached to a heat transfer tube of a waste combustion boiler.

  A general boiler recovers heat by arranging a heat exchange device on a flow path of combustion gas generated from the combustion device. As the heat exchange device, a heat transfer tube group in which a plurality of heat transfer tubes are combined is often used. The heat recovered by the heat transfer tube group is used in various ways, for example, by changing water into steam.

  What becomes a problem during heat recovery is deposits such as char that adhere to the heat transfer tubes. If a boiler is used for a certain period of time, char will adhere to the heat transfer tubes. Char is mainly composed of unburned carbon and ash contained in the combustion gas. If the accumulation of char increases, not only does the heat exchange rate worsen, but in severe cases, the heat transfer tube itself becomes clogged. Can cause serious problems.

  Therefore, a method of blowing gas (compressed air, steam, etc.) to a heat transfer tube is conventionally known as a method for removing char. In addition, a method is known in which deposits are dropped by applying an impact force to a heat transfer tube using a small steel ball or the like. Patent Document 1 shows an example in which deposits are removed using a shot sphere. Both of the two methods described above can be expected to have a certain effect on the removal of char.

JP 2009-127908 A

  In recent years, from the viewpoint of environmental protection, there are increasing cases of using waste as fuel for boilers. The waste is often solidified, and the solidified waste solidified fuel is referred to as RDF fuel or RPF fuel depending on the type of waste.

  The waste solidified fuel described above generally contains various components. Therefore, the combustion gas generated when the solid waste fuel is combusted is often a complex component. In particular, care must be taken when handling combustion gas containing components such as highly corrosive SOx.

  Moreover, the deposit | attachment by the combustion gas of a solid waste fuel may have strong adhesiveness, and it is easy to adhere to a heat exchanger tube. In particular, in the case of a heat exchange device of a type that exchanges heat by circulating gas in a heat transfer tube, the temperature of the gas greatly decreases at the gas inlet of the heat transfer tube, and sticky deposits adhere. For example, when a plurality of heat transfer tubes are arranged to form a heat transfer tube group, a large amount of deposits are generated at the end surface opening of the heat transfer tube group serving as the gas inlet of the heat transfer tube.

  A certain effect can be expected from the above-described method of removing deposits by spraying a cleaning gas (compressed air or the like) on the heat transfer tube. However, depending on the direction in which the gas is blown, it may result in pushing deposits into the heat transfer tubes, which may cause problems. In addition, the method of using the impact force of the steel ball described above takes time and effort to collect the used steel ball, and in the same manner as the gas blowing method described above, it is attached inside the heat transfer tube depending on the direction in which the steel ball collides. This can result in pushing in the kimono and can cause problems.

  The present invention has been made in view of the above-described problems, and proposes a deposit removing device that effectively removes sticky deposits adhering to a heat transfer tube of a waste combustion boiler.

In order to achieve the above object, the deposit removing apparatus according to the present invention comprises:
(1) A deposit removal device for removing sticky deposits attached to an end face opening of a heat transfer tube group that is disposed in a waste combustion boiler and recovers heat from combustion gas of solid waste fuel The deposit removing device is arranged opposite to the end face opening of the heat transfer tube group to which the sticky deposit adheres, passes through the casing of the waste combustion boiler, extends from the outside of the casing to the inside, and extends into the end face opening. A rotating shaft that is supported so as to be movable forward and backward, and that is rotatable, and a cleaning arm that is supported at one end by the rotating shaft and extends in a direction perpendicular to the opening of the end surface. By rotating in a state of being advanced toward the opening, the cleaning arm rotates in a state of being close to the end surface opening, thereby scraping off and removing the adhesive deposit.

(2) The deposit removing apparatus according to (1), wherein a rotatable swivel joint is arranged on the casing outer side of the rotating shaft, and the rotating shaft and the cleaning arm are made hollow, thereby removing the swivel joint. A gas passage communicating to the tip of the cleaning arm was formed.

(3) The deposit removing device according to (1) or (2), wherein an arm storage portion in which a groove portion for storing a cleaning arm is formed is disposed in a casing penetration portion of the rotating shaft.

(4) The deposit removing apparatus according to any one of (1) to (3), wherein a conical protrusion is formed at one end of the rotary shaft on the end face opening side, and a cleaning arm is formed. When rotating in a state of being close to the end surface opening, a part or all of the protruding portion is inserted into the opening of the heat transfer tube.

  According to the deposit removing device of the present invention, it is possible to effectively remove sticky deposits adhering to the heat transfer tube group end face opening of the waste combustion boiler.

It is a figure explaining the structure of the waste combustion boiler in connection with embodiment of this invention. It is a figure explaining the structure of the deposit removal apparatus according to the embodiment of the present invention. It is a figure explaining the arrangement | positioning of a deposit removal apparatus and a heat exchanger tube group in connection with embodiment of this invention. It is a conceptual diagram explaining the flow of the gas inside the deposit removal apparatus according to the embodiment of the present invention. It is a figure explaining the state which made the cleaning arm of the deposit removal apparatus related to embodiment of this invention adjoin to the heat exchanger tube group. It is a figure explaining the state which stored the cleaning arm of the deposit | attachment removal apparatus concerning the embodiment of this invention in the arm storage part. It is a conceptual diagram explaining the state which rotated the cleaning arm of the deposit removal apparatus according to the embodiment of the present invention close to the heat transfer tube group. It is a figure explaining the state which took out the cleaning arm of the deposit removal apparatus concerning embodiment of this invention out of the casing. It is a figure explaining the structure of the deposit removal apparatus concerning other embodiment by this invention. It is a conceptual diagram for demonstrating the condition to which a sticky deposit adheres according to the prior art of a waste combustion boiler.

Hereinafter, examples of preferred embodiments of the present invention will be described in detail with reference to the drawings.
1 to 8 relate to the drawings for explaining the embodiment of the present invention, and show preferred examples thereof. FIG. 1 is a diagram for explaining the configuration of a waste combustion boiler, and FIG. It is a figure explaining the structure of a deposit | attachment removal apparatus. FIG. 3 is a diagram for explaining the arrangement of the deposit removing device and the heat transfer tube group, FIG. 3 (2) is a diagram of FIG. 3 (1) observed in the A direction, and FIG. 3 (3) is FIG. It is the figure which observed 1) in the B direction. FIG. 4 is a conceptual diagram illustrating the flow of gas inside the deposit removal device. FIG. 5 is a view for explaining a state in which the cleaning arm of the deposit removing device is brought close to the heat transfer tube group, and FIG. 5 (2) is a view of FIG. 5 (1) observed in the A direction. FIG. 6 is a view for explaining a state where the cleaning arm is stored in the arm storage portion, and FIG. 6 (2) is a view of FIG. 6 (1) observed in the B direction. FIG. 7 is a conceptual diagram illustrating a state in which the cleaning arm of the deposit removing device according to the embodiment of the present invention is rotated close to the heat transfer tube group, and FIG. 8 is a diagram illustrating the cleaning arm of the deposit removing device outside the casing. It is a figure explaining the state taken out in (1).
FIG. 9 is a view for explaining the configuration of the deposit removing apparatus according to another embodiment of the present invention.
For reference, FIG. 10 is a conceptual diagram for explaining the situation where sticky deposits adhere to the related art of a waste combustion boiler.

FIG. 1 shows the configuration of a waste combustion boiler 100 used in an embodiment of the present invention (sometimes referred to as a first embodiment).
A waste combustion boiler 100 shown in FIG. 1 (sometimes abbreviated as “boiler 100”) includes an air inlet 55 at the lower part of a casing, and a combustion bed 54, a fuel supply port 51, and an ignition burner 61 above it. Is arranged. In addition, a temperature raising burner 63 is disposed above the ignition burner 61, and a plurality of secondary air blowing nozzles (not shown) are disposed.

  The fuel (in this embodiment, waste solid fuel) supplied from the fuel supply port 51 to the combustion bed 54 is ignited by the air supplied from the air introduction port 55 and the ignition burner 61, and further by the temperature raising burner 63. Elevated temperature combustion is efficiently performed, and high-temperature combustion gas is generated. The boiler 100 shown in FIG. 1 comprises the combustion chamber 60 by the above-mentioned structure.

  Above the combustion chamber 60 described above, a partition plate 65 for separating the combustion chamber 60 and a heat exchange chamber 30 described later is disposed. The partition plate 65 that separates the combustion chamber 60 and the heat exchange chamber 30 is provided with an opening (in this embodiment, the right side of the casing in the drawing) so that the combustion gas rises and the heat exchange chamber. A passage for entering 30 is formed.

A first heat transfer tube group 31 formed by arranging a plurality of heat transfer tubes extending in the horizontal direction is arranged on the partition plate 65, and a second heat transfer tube group 32 is arranged above the first heat transfer tube group 32. .
In the present embodiment, as shown in FIG. 3B, the first heat transfer tube group 31 is formed by 63 heat transfer tubes (vertical 7 rows, horizontal 9 rows).

Further, the boiler 100 shown in FIG. 1 has a first heat transfer tube so that the combustion gas rising from the opening of the partition plate 65 is not directly supplied to the second heat transfer tube group 32 as it is. A partition plate 35 is disposed between the group 31 and the second heat transfer tube group 41.
The partition plate 35 divides the right side portion in the drawing in the casing, and the combustion gas ascends the right side portion of the casing without passing through the first heat transfer tube group 31 and the second heat transfer tube group 32 and is discharged from the combustion gas discharge port 59. To be prevented.

  Although details will be described later, the combustion gas that has risen from the combustion chamber 60 by the partition plate 65 and the partition plate 35 passes through the first heat transfer tube group and then passes through the second heat transfer tube group, and the combustion gas discharge port 55. The structure is more discharged.

Note that water is supplied around the heat transfer tubes forming the first heat transfer tube group 31 and the second heat transfer tube group 32, and heat exchange is performed from the combustion gas to water via the heat transfer tubes.
The water subjected to the heat exchange becomes a high temperature and becomes steam, and is stored in the steam drum 70 installed on the boiler 100 and used in various ways. The boiler 100 shown in FIG. 1 comprises the heat exchange chamber 30 by the structure of the 1st heat exchanger tube group 31 and the 2nd heat exchanger tube group 32 which were mentioned above.

  Here, for reference, the adhesion state of the deposit will be briefly described based on the example of the prior art shown in FIG. When the fuel R is supplied from the fuel supply port 51 of the waste combustion boiler 200, the fuel is burned on the combustion bed 54 to generate combustion gas. The combustion gas rises, enters the heat exchange chamber 30 from the combustion chamber 60, passes through the first heat transfer tube group 31 and the second heat transfer tube group 32, and is discharged from the combustion gas discharge port 59. At this time, it is expected that a large amount of contaminants Y will be generated at the end surface opening of the first heat transfer tube group 31 where the temperature of the combustion gas starts to decrease.

  Therefore, the deposit removing device 10 according to the present embodiment is disposed to face the end surface opening of the first heat transfer tube group 31 that is expected to be most likely to have a sticky deposit in the boiler 100. The The arrangement | positioning condition of the deposit | attachment removal apparatus 10 is shown in FIG.

  That is, in this embodiment, the deposit removing device 10 is provided on the side of the first heat transfer tube group 31 to which the combustion gas is supplied. Usually, since there is an inspection port in this part, it is preferable to attach the deposit removing device 10 using this.

Hereinafter, the configuration of the deposit removal device 10 will be described in detail.
As shown in FIG. 2, the deposit removing apparatus 10 according to the present embodiment includes a rotating shaft 12, a cleaning arm 14, a shaft head 15, a handle 18, a swivel joint 16, and the like.

The rotary shaft 12 is attached to a second support portion 24, and the second support portion 24 is rotatably supported by a first support portion 22 fixed to the casing of the boiler 100.
FIGS. 8A and 8B show a situation where the position of the second support portion 24 is changed. Although details will be described later, FIG. 8 (1) shows a normal state of the deposit removing device 10, and (2) shows a state at the time of maintenance. Hereinafter, in order to simplify the description, the configuration of the deposit removing device 10 will be described based on the normal state shown in FIG.

The rotary shaft 12 is supported by the second support member 24 so as to be able to advance and retreat toward the first heat transfer tube group 31, and is supported rotatably about the central axis of the rotary shaft 12. The rotating shaft 12 extends in a horizontal direction from the outside of the casing toward the inside so as to penetrate the casing of the boiler 100 in a normal state.
Although not shown in detail, in this embodiment, a high heat-resistant gland packing 24A or the like is appropriately disposed as a seal member in a gap generated at the boundary between the boiler 100 and the outside as necessary. In the normal state shown in FIG. 8A, the space between the second support portion 24 and the arm storage portion 26 is also sealed.

A cleaning arm 14 is attached to the inner side of the casing of the rotary shaft 12, and a shaft head 15 is provided at the inner end of the casing.
In this embodiment, the cleaning arm 14 has a shape in which a flat bar 14B whose end is obliquely chamfered is welded to a cylindrical pipe 14A, and it is easy to remove deposits when rotated. It has a structure. However, the range of the shape of the cleaning arm 14 applicable to the present invention is not limited thereto, and can be changed within a range not departing from the present invention, such as a flat plate shape, a prismatic shape, or a triangular prism shape, depending on the situation. Alternatively, comb-shaped protrusions or blades may be provided.

  Here, the cleaning arm 14 is supported at one end by the rotating shaft 12 and extends in a direction perpendicular to the longitudinal direction of the rotating shaft 12. The shaft head 15 is a conical protrusion. Although details will be described later, when the cleaning arm 14 rotates in a state of being close to the end face opening of the first heat transfer tube group 31, the cleaning arm 14 is close to and close to the end face opening of the first heat transfer tube group 31. It becomes a state to do. Further, the shaft head 15 is partly or entirely inserted as a protrusion into one heat transfer tube forming the first heat transfer tube group 31.

  A handle 18 (a cross handle in this embodiment) is provided on the casing outer side of the rotary shaft 12, and is configured such that the rotary shaft 12 can be rotated by turning the handle 18. A swivel joint 16 is attached to the outer end of the casing. The swivel joint 16 is a joint for connecting a non-rotating pipe to a rotatable pipe.

  In the present embodiment, as shown in FIG. 4, the rotary shaft 12 and the cleaning arm 14 are formed by pipes to be hollow, thereby forming a gas passage communicating from the cleaning gas supply port SR to the cleaning gas outlet. . Note that the swivel joint 16 is used to connect to the cleaning gas supply port SR in order to use the rotating shaft 12 in a rotated state.

In the present embodiment, the arm storage portion 26 is disposed in the casing penetrating portion of the rotary shaft 12. A storage groove 26 </ b> B is formed in the arm storage portion 26.
Here, as shown in FIG. 2, in a normal state, the second support portion 24 is in contact with the surface of the arm storage portion 26 on the outer side of the casing. As shown in FIG. 6, when the cleaning arm 14 moves in a direction away from the first heat transfer tube group, the cleaning arm 14 is stored in the storage groove 26B. When performing maintenance on the cleaning arm 14 of the deposit removing device 10, the second support 24 can be rotated and taken out of the casing as shown in FIG.

Hereinafter, a method for removing the deposit using the deposit removing apparatus 10 will be described in detail.
When a plurality of heat transfer tubes for recovering heat from the combustion gas are arranged, a large amount of adhesive deposits adhere to the end surface opening of the first heat transfer tube group 31 serving as a gas inlet.
As shown in FIG. 6, the cleaning arm 14 is moved in a direction away from the first heat transfer tube group between the start of the operation of the boiler 100 and the adhering matter, so that the inside of the storage groove 26B. To store. When the solid waste fuel is burned, corrosive combustion gas may be generated. However, storing the cleaning arm 14 in the storage groove 26B reduces the contact ratio with the combustion gas.

  Further, since corrosion due to combustion gas is likely to occur as the temperature rises, the rotating shaft 12 and the cleaning arm 14 are cooled by appropriately flowing gas in a gas passage communicating to the tip of the cleaning arm 14 as necessary. Keep the temperature down. As a result, the possibility of corrosion can be further reduced.

  More specifically, during normal standby, the cleaning arm 14 is pulled from the first heat transfer tube group side 31 to the casing wall side to avoid a state where the cleaning arm 14 is exposed to a flow of high-temperature gas (700 to 800 ° C.). In addition, by flowing cooling air (using compressed air in the present embodiment) through the cleaning arm 14, the device main body is maintained at a constant temperature (500 ° C. or less), thereby improving the device life and safety.

  If a large amount of adhesive deposits adhere to the end face opening of the first heat transfer tube group 31 after operating for a certain period of time, the rotary shaft 12 is pushed into the casing to move the rotary shaft 12 to the end face of the first heat transfer tube group 31. The cleaning arm 14 is moved forward toward the opening, and is brought into a state in which the cleaning arm 14 is brought close to the end surface opening of the first heat transfer tube group 31.

  In the present embodiment, when the cleaning arm 14 comes close to the end face opening of the first heat transfer tube group 31, the opening of the heat transfer tube in which the shaft head 15 is located at the center of the first heat transfer tube group 31. Therefore, the rotary shaft 12 is supported at two points, that is, the second support portion 24 and the shaft head 15. In other words, the rotating shaft 12 is supported by the second support portion 24 by pressing with the gland packing 24 </ b> A, and supported by the shaft head 15 with the pipe support.

  Then, by rotating the rotary shaft 12 using the handle 18, the cleaning arm 14 rotates in a state of being close to the end surface opening, thereby scraping off and removing the adhesive deposits. In the present embodiment, as described above, since the rotating shaft 12 is supported at the two points of the second support portion 24 and the shaft head 15, the excellent effect that the rotating shaft is not stably shaken is obtained. Play. Therefore, even if the rotating shaft 12 is rotated with a strong force, the rotating shaft is not easily shaken, and the scraped state of the cleaning arm 14 is stabilized, so that effective deposit removal is possible.

At this time, as shown in FIG. 7 (2), by supplying the gas from the cleaning gas supply port SR and ejecting the gas from the cleaning gas outlet SH, the adhesiveness of the portion that does not reach the cleaning arm 14 The deposits can be washed away.
In addition, since the blowing direction of the gas by this embodiment becomes a direction orthogonal to the longitudinal direction of a heat exchanger tube, there is little possibility of pushing in a deposit into a heat exchanger tube, and it is suitable as a removal method.

Here, for example, if the first heat transfer tube group 31 is arranged in a circular shape, it is possible to arrange the cleaning arm 14 so as to reach every corner by rotating. However, in the case where the first heat transfer tube group 31 is arranged in a rectangular shape as in the present embodiment, it is difficult to rotate the cleaning arm 14 to reach the corner.
In the present embodiment, it is possible to cope with the arrangement of the heat transfer tube groups arranged in various shapes by using both the scraping effect of the rotating cleaning arm 14 and the blowing effect by gas in a functional combination. It is preferable.

  When the operation of the boiler 100 is stopped and the cleaning arm 14 of the deposit removing device 10 is maintained, as shown in (2) of FIG. 8, the second support portion 24 is rotated and taken out of the casing. Therefore, maintenance can be easily performed.

As described above, the deposit removing device 10 according to the present embodiment has a structure that enables rotation and insertion / removal of a certain distance.
At the time of cleaning, the cleaning arm 14 is pushed to the tube plate surface that is the end surface opening portion, and the flat bar 14B that becomes the scraping plate portion is pressed against the tube plate surface, and then rotated to be brought into contact with the tube plate surface of the boiler. It is a structure that removes the adhered matter.
After cleaning, the cleaning arm 14 can be pulled out from the tube plate surface to the wall side (to be pulled into the storage groove 26B, which is a notch portion of the furnace), thereby preventing high temperature conditions.

  Moreover, the deposit removing apparatus 10 according to the present embodiment has a cleaning arm 14 and a rotating shaft 12 as a pipe structure, and constantly flows cooling air to keep the device main body at a constant temperature, thereby improving the device life and safety. Since the cooling air uses compressed air, by setting the outlet of the compressed air to the nozzle tip side, it is possible to remove deposits on the tube plate surface that cannot be reached by this device due to the ejection pressure.

  Therefore, according to the deposit removing apparatus 10 according to the present embodiment, it is possible to effectively remove the sticky deposit adhering to the end surface opening of the first heat transfer tube group 31 of the boiler 100.

Hereinafter, other embodiments according to the present invention will be briefly described with a focus on differences from the above-described embodiments.
Another embodiment according to the invention is shown in FIG. The deposit removing device 10B shown in FIG. 9 includes the rotating shaft 12, the cleaning arm 14, the handle 18, the swivel joint 16, and the like, as in the above-described embodiment.

Here, the deposit removing device 10B shown in FIG. 9 is different from the deposit removing device 10 described above in the way of supporting the rotary shaft 12.
The deposit removing device 10 according to the above-described embodiment has a structure in which the rotating shaft 12 is supported at two points, that is, a gland packing 24 </ b> A disposed on the second support portion 24 and a protrusion formed on the shaft head 15. Yes.

  On the other hand, in the other embodiment shown in FIG. 9, the support bracket 24 </ b> B is disposed on both sides of the second support portion 24, i.e., on the inside and outside of the second support portion 24. The shaft 12 is supported. Therefore, the shape of the shaft head 15B is flat.

  When the cleaning arm 14 comes close to the end face opening of the first heat transfer tube group 31, the flat shaft head 15B comes into contact with the vicinity of the end face opening of the first heat transfer tube group 31, and the cleaning arm 14 The adhesive deposit 14 is scraped off and removed by rotating in a state where 14 is close to the end face opening.

In the other embodiment shown in FIG. 9, since the rotary shaft 12 is supported at both ends of the second support portion 24, it is not necessary to insert the shaft head 15B into the opening of the heat transfer tube.
Therefore, it is possible to adapt to a case where it is difficult to insert the shaft head 15 into the opening of the heat transfer tube due to a design problem, for example, due to the arrangement of the heat transfer tube.

  In addition, there may be a case where the shaft head 15 cannot be inserted into the heat transfer tube due to reasons such as when the heat transfer tube is made of a material that is easily damaged. Even in such a case, the other embodiment shown in FIG. 9 can be used and is the preferred form.

  The deposit removing device of the present invention can be suitably used as a device for removing sticky deposits adhering to the heat transfer tube group end face opening of a waste combustion boiler.

10 Deposit removal device
10B deposit removal apparatus (other embodiment)
12 Rotating shaft 14 Cleaning arm 15 Shaft head 15B Shaft head (flat type)
16 Swivel joint 18 Handle 22 First support portion 24 Second support portion 30 Heat exchange chamber 31 First heat transfer tube group 32 Second heat transfer tube group 60 Combustion chamber 100 Waste combustion boiler

Claims (4)

A deposit removing device for removing sticky deposits attached to an end face opening of a heat transfer tube group that is disposed in a waste combustion boiler and recovers heat from a combustion gas of waste solid fuel,
The deposit removing device is arranged facing the end face opening of the heat transfer tube group to which the sticky deposit adheres, passes through the casing of the waste combustion boiler, extends from the outside of the casing to the inside, and faces the end face opening. A rotating shaft that is supported so as to freely move forward and backward.
And a cleaning arm that is supported at one end by the rotating shaft and extends in a direction perpendicular to the end surface opening,
An adhering matter removing device that scrapes and removes adhesive adhering matter by rotating a rotating shaft in a state of being advanced toward the end surface opening, thereby rotating the cleaning arm in a state of being close to the end surface opening.   The gas passage which communicates from the swivel joint to the tip of the cleaning arm is formed by disposing a rotatable swivel joint on the outer side of the casing of the rotating shaft and making the rotating shaft and the cleaning arm hollow. Deposit removal device.   The deposit removing apparatus according to claim 1 or 2, wherein an arm storage portion in which a groove portion for storing a cleaning arm is formed in a casing penetrating portion of the rotating shaft.   When a conical protruding portion is formed at one end of the rotating shaft on the end surface opening side and the cleaning arm rotates in a state of being close to the end surface opening, a part or all of the protruding portion is an opening of the heat transfer tube. The deposit removing apparatus according to any one of claims 1 to 3, wherein the deposit removing apparatus is in a state of being inserted into a portion.

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