JP5078320B2 - Temperature reduction tower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature reduction tower which controls detention due to drift and secondary flow in a tower body of a temperature reduction tower. <P>SOLUTION: The temperature reduction tower has the cylindrical tower body 20, a combustion exhaust-gas introduction part 30 arranged at the upper part of the tower body 20, a combustion exhaust-gas supplying pipe 40 arranged at the combustion exhaust-gas introduction part 30, a combustion exhaust-gas exhausting pipe 50 and a water spray nozzle 60 arranged in the tower body 20. The combustion exhaust-gas introduction part 30 is formed by a roofed cylindrical diffusion part 31 and a rectification part 32 of inverted head-cut conical form arranged at the lower part of the diffusion part 31, while the combustion exhaust-gas supplying pipe 40 is held inclined and upwards to be connected to the side 34 of the rectification part 32. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a temperature reducing tower that reduces the temperature of high-temperature combustion exhaust gas discharged from an incinerator, a gasification melting furnace, or the like using the heat of vaporization of water.

  In general, a large amount of ash and dust is contained in high-temperature combustion exhaust gas emitted from incinerators that incinerate waste such as municipal waste and industrial waste, and kiln type gasification and melting furnaces that gasify and melt. Has been. For this reason, it is necessary to remove the ash and dust in combustion exhaust gas with a dust collector, and in many cases, dust collection by a bag filter is performed.

  However, since the bag filter generally uses a flammable fibrous filter cloth, the bag filter has low heat resistance, and it is not preferable that the temperature of the combustion exhaust gas exceeds 250 ° C. For this reason, a waste heat boiler is installed in the front stage of the bag filter to cool the combustion exhaust gas (see, for example, Patent Document 1), or a combustion exhaust gas cooling tower is installed in the front stage of the bag filter to reduce the combustion exhaust gas. Cooling is performed (for example, refer to Patent Document 2).

  As shown in FIG. 10, this combustion exhaust gas cooling tower introduces combustion exhaust gas g of around 400 ° C. into the rectifying tower 124 from the exhaust gas introduction pipe 123 and sprays the cooling water w from the nozzle 122 provided inside the tower main body 121. Thus, the combustion exhaust gas g is cooled to a predetermined temperature (for example, 200 ° C. or lower).

  However, in this flue gas cooling tower, the flue gas introduction pipe 123 for introducing the flue gas g into the tower body 121 is provided substantially horizontally on the side surface of the rectifying tower 124, so that the ash in the flue gas g is removed from the flue gas introduction pipe 123. In addition to being easily deposited inside, the gas flow and flow velocity of the combustion exhaust gas g change due to the accumulation of ash f.

For this reason, the flue gas g introduced into the tower main body 121 is liable to drift or stay due to the secondary flow of the flue gas g, and contact with the cooling water w sprayed from the nozzle 122. However, there is a problem that it is difficult to perform uniformly.
JP 2002-102647 A JP 2004-267856 A

  The present invention has been made in order to solve the above-described problems, and the object of the present invention is to generate a drift of combustion exhaust gas in the tower body of the temperature-decreasing tower and a stay due to the secondary flow. An object of the present invention is to provide a temperature reducing tower that can suppress the above.

Invention, a tubular column body, provided we are at the top of the tower body and a lidded cylindrical diffusion section, an inverted truncated cone-shaped rectifier provided on the lower portion of the diffusing unit according to claim 1 A flue gas introduction part formed from the combustion part, a flue gas supply pipe provided in the flue gas introduction part, a flue gas exhaust pipe provided obliquely upward with respect to the tower body at the bottom of the tower body , In a temperature-decreasing tower provided with a water spray nozzle provided in the tower body, the combustion exhaust gas supply pipe is connected obliquely upward and connected to the side surface of the inverted conical rectification section of the combustion exhaust gas introduction section , and the combustion exhaust gas The temperature reducing tower is characterized in that the discharge pipe is protruded in the tower main body so that a tip opening portion thereof is located on the axial center of the tower main body .

  The present invention according to claim 1 includes a cylindrical tower main body, a combustion exhaust gas introduction part provided at the upper part of the tower main body, a combustion exhaust gas supply pipe provided at the combustion exhaust gas introduction part, and a lower part of the tower main body In the temperature reduction tower provided with the combustion exhaust gas discharge pipe provided in the column and the water spray nozzle provided in the tower body, the combustion exhaust gas introduction part is provided with a covered cylindrical diffusion part and an inverted part provided at the lower part of the diffusion part. Since it is formed by a truncated conical rectification unit and connected to the side surface of the rectification unit with the combustion exhaust gas supply pipe obliquely upward, the combustion exhaust gas ejected from the combustion exhaust gas inflow tube into the combustion exhaust gas introduction unit is Combustion exhaust gas that collides with the center of the ceiling of the covered cylindrical diffusion part of the combustion exhaust gas introduction part and diffuses to the surroundings while reversing, and diffused in the diffusion of the covered cylindrical part is the slope of the truncated cone shape of the rectification part Rectified while flowing down along It became.

  For this reason, it has become possible to prevent the stagnant due to the drift or secondary flow of the combustion exhaust gas flowing into the tower body from the combustion exhaust gas introduction section. In addition, contact with the water sprayed from the water spray nozzle is also performed uniformly.

  In the present invention according to claim 2, since the flue gas exhaust pipe is provided so that a tip opening thereof is positioned substantially on the axial center of the tower body, a synergistic effect with the flue gas introduction portion is obtained. It has become possible to further prevent stagnation due to the drift or secondary flow of combustion exhaust gas in the tower body.

  According to the third aspect of the present invention, since the flue gas exhaust pipe is provided obliquely upward with respect to the tower main body, it is also possible to narrow the interval with the bag filter located at the subsequent stage.

The present invention described in claim 4, when the inner diameter of the column body and is D, the combustion exhaust gas introducing portion of an inner diameter D ₁ of the D / 2~3D / 2, connected to the flue gas inlet section and the tower body Since the inner diameter D _{2 of the} connecting portion is set to D / 3 to D / 2 and D ₁ ≧ D ₂ , it becomes possible to smoothly flow the combustion exhaust gas from the combustion exhaust gas introduction portion to the tower main body, And retention due to the secondary flow can be prevented.

According to the fifth aspect of the present invention, since the inclination angle θ ₁ of the flue gas supply pipe is set to 45 ° to 65 °, the ceiling of the covered cylindrical diffusion portion of the covered flue gas introduction section from the flue gas supply pipe is provided. It became possible to make combustion exhaust gas collide toward the center. For this reason, it became possible to reverse combustion exhaust gas toward the axial center of a tower main body, and it became possible to prevent the residence resulting from a drift and a secondary flow. In addition, since the flue gas supply pipe itself has a predetermined inclination angle, it is possible not only to prevent ash accumulation but also to prevent fluctuations in the gas flow and flow velocity of the flue gas due to ash accumulation. It became possible to do.

According to the sixth aspect of the present invention, since the inclination angle θ ₂ of the rectification unit in the combustion exhaust gas introduction unit is set to 45 ° to 65 °, the combustion exhaust gas can be smoothly rectified by the throttling effect of the rectification unit. In addition, it became possible to prevent ash accumulation.

According to the seventh aspect of the present invention, since the inclination angle θ ₃ of the flue gas exhaust pipe is set to 45 ° to 65 ° in the first aspect, ash accumulation can be prevented. In addition, it has become possible to reduce the distance from the bag filter located in the subsequent stage.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the temperature reducing tower 10 includes a cylindrical vertically long tower body 20, a combustion exhaust gas introduction section (also referred to as “chamber”) 30 provided on the top of the tower body 20, and a combustion exhaust gas introduction section. 30, a flue gas supply pipe 40 connected to 30, a flue gas exhaust pipe 50 provided in the lower part of the tower body 20, and a spray nozzle (referred to as a water spray nozzle) 60 provided in the tower body 20. Further, an ash discharge device (not shown) is provided at the bottom of the tower main body 20 so that the ash accumulated at the bottom of the tower main body 20 is periodically discharged.

  The flue gas introduction part 30 is formed by a covered cylindrical diffusion part 31 and an inverted truncated conical rectification part 32 provided at the lower part of the diffusion part 31, and the outlet 32 a of the rectification part 32 has a cylindrical shape or a diameter. It connects with the upper end 20a of the tower main body 20 via the connection part 33 which expands gradually. The combustion exhaust gas supply pipe 40 is connected to the side surface 34 of the inverted truncated conical rectification unit 32, and the combustion exhaust gas g supplied from the combustion exhaust gas supply pipe 40 is formed on the horizontal ceiling 31 a of the covered cylindrical diffusion part 31. Colliding with approximately the center. The combustion exhaust gas supply pipe 40 is directed to the vicinity of the axis C of the tower body 20 as shown in FIG.

Here, as shown in FIG. 1, the flue gas supply pipe 40 is provided so as to be inclined upward by a predetermined angle θ _{1 with} respect to the horizontal plane G ₂ , and the inclination angle θ ₁ is 45 °. A range of ˜65 ° is preferred. Furthermore, the range of 50 ° to 60 ° is preferable. When the inclination angle θ ₁ of the combustion exhaust gas supply pipe 40 is less than 45 °, ash is likely to be deposited in the combustion exhaust gas supply pipe 40 and there is a possibility that the interval with the waste heat boiler in the previous stage may be widened. On the other hand, when the inclination angle θ ₁ of the combustion exhaust gas supply pipe 40 exceeds 65 °, it becomes easy to interfere with the tower body 20, so that installation becomes difficult.

Further, the inclined surface 34 of the rectifying unit 32 in the combustion exhaust gas introducing unit 30 is inclined by a predetermined angle θ _{2 with} respect to the horizontal plane G ₁ , and the inclination angle θ ₂ is in a range of 45 ° to 65 °. preferable. Furthermore, the range of 50 ° to 60 ° is preferable. When the inclination angle θ ₂ of the rectifying unit 32 is less than 45 °, ash is easily deposited in the rectifying unit 32. Conversely, when the inclination angle θ ₂ of the rectifying unit 32 exceeds 65 °, the height of the rectifying unit 32 increases.

  The tower body 20 includes a cylindrical barrel portion 21, a truncated cone-shaped enlarged portion 22 provided on the upper portion of the barrel portion 21, and an inverted truncated cone-shaped reduced diameter portion 23 provided on the lower portion of the barrel portion 21. A plurality of water spray nozzles 60 are provided in the enlarged portion 22. These water spray nozzles 60 are provided at predetermined intervals in the circumferential direction of the enlarged portion 22, and their tips are directed to the axis C of the tower body 20 (see FIG. 2).

  The water spray nozzle 60 is a two-fluid pressure spray type nozzle, and sprays water w from the fine hole 61 at the tip of the nozzle by high-pressure air a. As shown in FIG. 5, the water spray nozzle 60 is formed by an L-shaped nozzle portion 62 and a double tube 63 connected to the nozzle portion 62, and from an inner tube 63 a constituting the double tube 63. Water w is supplied, and high-pressure air a is supplied from the outer pipe 63b. The water spray nozzle 60 is attached to the enlarged portion 22 so that the L-shaped nozzle portion 62 faces vertically downward. The water spray nozzle 60 is covered with a cylindrical cover 64 so that ash in the combustion exhaust gas does not adhere. The cover 64 has an opening 65 immediately below the nozzle portion 62, and is supported by a radial support 66 provided on the outer tube 63b.

  Further, the flue gas exhaust pipe 50 is provided obliquely upward so as to penetrate the trunk portion 21 of the tower body 20, and the tip opening 51 is located on the same horizontal plane (not shown) as the lower end portion 21 a of the trunk portion 21. At the same time, it is positioned near the axis C of the tower body 20. The combustion exhaust gas discharge pipe 50 is directed to the vicinity of the axis C of the tower body 20 as shown in FIG.

The flue gas discharge pipe 50 is inclined by a predetermined angle theta ₃ with respect to the horizontal plane G _3, as the inclination angle theta _3, is preferably in the range of 45 ° to 65 °. Furthermore, the range of 50 ° to 60 ° is preferable. When the inclination angle θ ₃ of the flue gas exhaust pipe 50 is less than 45 °, ash is likely to accumulate in the flue gas exhaust pipe 50. On the contrary, when the inclination angle θ ₃ of the combustion exhaust gas discharge pipe 50 exceeds 65 °, it is easy to interfere with the tower body 20. The combustion exhaust gas discharge pipe 50 is provided toward the vicinity of the axis C of the tower body 20 as shown in FIG.

Further, when the diameter of the barrel portion 21 of the column body 20 is D, the diameter D ₂ of diameter D ₁ and the connecting portion 33 of the lidded cylindrical spreading section 31 in the flue gas inlet section 30 may be configured as follows ing.
D ₁ = D / 2 to 3D / 2 (1)
D ₂ = D / 3 to D / 2 (2)
However, D ₁ ≧ D ₂

  Further, the flow rate of the combustion exhaust gas supplied to the temperature reducing tower 10 is 7.5 to 12.5 m / s.

  As shown in FIG. 6, the flue gas g supplied from the waste heat boiler or the flue gas cooling tower (not shown) to the flue gas supply pipe 40 is from the flue gas supply pipe 40 inclined obliquely upward. It is ejected toward the ceiling 31a of the bottomed cylindrical diffusion part 31 of the combustion exhaust gas introduction part 30 and collides with the approximate center of the horizontal ceiling 31a of the bottomed cylindrical diffusion part 31.

  The flue gas g that collides with the approximate center of the ceiling 31a of the bottomed cylindrical diffusion part 31 diffuses around while being reversed at the ceiling 31a of the bottomed cylindrical diffusion part 31. The combustion exhaust gas g diffused along the ceiling 31a of the diffusion part 31 flows down along the inverted truncated conical rectification part 32 in the combustion exhaust gas introduction part 30, and connects the combustion exhaust gas introduction part 30 and the tower body 20. It flows into the tower main body 20 from the connecting portion 33 having a cylindrical shape or a diameter gradually increasing.

  The flue gas g flowing into the tower main body 20 from the connecting portion 33 flows down along the enlarged portion 22 of the tower main body 20 and flows in a flow almost parallel to the axis C of the tower main body 20, and flows down. Is supplied to a bag filter (not shown) in the subsequent stage through a flue gas exhaust pipe 50 having a front end opening 51 in the vicinity of the axial center C.

  On the other hand, since water w is sprayed vertically downward from fine holes (not shown) at the tips of a plurality of water spray nozzles 60 provided in the circumferential direction of the enlarged portion 22 of the tower body 20, as shown in FIG. As described above, the water w is uniformly diffused in the cross section of the tower body 20. For this reason, the combustion exhaust gas g flowing down in the tower main body 20 is uniformly cooled by the water w uniformly diffused in the tower main body 20 (for example, around 400 ° C. → 200 ° C. or less). At this time, the water w sprayed from the water spray nozzle 60 is heated and evaporated by the combustion exhaust gas g and does not adhere to the inner wall of the tower body 20. The combustion exhaust gas g cooled in the tower body 20 is supplied to the next process from the combustion gas discharge pipe 50 provided at the lower part of the tower body 20.

(Example)
FIG. 7 is a heat flow diagram of the temperature reducing tower according to the present invention. According to this heat flow diagram, it can be seen that the temperature reducing tower according to the present invention has almost no stagnant combustion gas due to a drift or secondary flow.

  On the other hand, when the combustion exhaust gas introduction part is cylindrical (Comparative Example 1), as shown in FIG. 8, the air flow is unevenly distributed on the outlet side (combustion exhaust gas outflow side), and the secondary flow is retained on the outlet side. An area is created.

  When exhaust gas is supplied in the tangential direction of the combustion exhaust gas introduction part (Comparative Example 2), as shown in FIG. 9, a swirling flow is generated in the combustion exhaust gas introduction part, and this swirling flow flows into the tower body. A swirling flow is generated inside the tower body. The analysis code used for this heat flow is STAR-CD Ver. 3.24.

It is sectional drawing of the temperature reduction tower which concerns on this invention. It is XX sectional drawing of FIG. It is an arrow view of the arrow Z direction of FIG. It is YY sectional drawing of FIG. It is a side view including a partial cross section of a water spray nozzle. It is action | operation explanatory drawing of the temperature reduction tower which concerns on this invention. It is a heat | fever flow diagram of the temperature reduction tower which concerns on this invention. 2 is a heat flow diagram of Comparative Example 1. FIG. 6 is a heat flow diagram of Comparative Example 2. FIG. It is sectional drawing of the conventional waste gas cooling tower.

Explanation of symbols

20 Tower body 30 Combustion exhaust gas introduction part 31 Covered cylindrical diffusion part 32 Inverted truncated conical rectification part 34 Side face of rectification part 40 Combustion exhaust gas supply pipe 50 Combustion exhaust gas discharge pipe 60 Water spray nozzle

Claims (1)

A cylindrical column body, are found provided on the top of the tower body and a lidded cylindrical diffusion section, the combustion exhaust gas introduced formed from an inverted truncated conical rectifying portion provided in the lower part of the diffusing section A combustion exhaust gas supply pipe provided in the combustion exhaust gas introduction part, a combustion exhaust gas exhaust pipe provided obliquely upward with respect to the tower main body at a lower portion of the tower main body, and a water spray nozzle provided in the tower main body In the temperature reduction tower equipped with
The flue gas supply pipe is obliquely upward and connected to the side surface of the inverted truncated conical rectifier of the flue gas introduction part , and the flue gas exhaust pipe has a tip opening on the axis of the tower body. A temperature-decreasing tower, wherein the tower body is provided so as to protrude from the tower body .

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