JP2003175314A - Spray type absorption column of exhaust gas desulfurization equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve the compactification of the spray type absorption column of exhaust gas desulfurization equipment to reduce power consumption. <P>SOLUTION: In the spray type absorption column of exhaust gas desulfurization equipment, the spray type absorption column is partitioned by an inner partition plate 56 so as to form opening parts 52 and 54 above and below the partition plate 56 and a liquid seal is formed to the lower part of the partition plate 56 by an absorbing solution tank 38 to cut off a gas flow. The direction of the gas flow is reversed in the vicinity of the top part of the column to form a gas up-flow part 10 and a gas down-flow part 12. A main circulating-spray header 58 is incorporated in the inner partition plate 56 to form an integrated structure. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray type absorption tower of a wet flue gas desulfurization device for removing sulfur oxides and dust in flue gas discharged from a thermal power plant or the like, and more particularly to downsizing and power consumption. The present invention relates to a spray-type absorption tower of a wet flue gas desulfurization device that can reduce

[0002]

2. Description of the Related Art As a flue gas desulfurization device used to remove sulfur oxides in combustion exhaust gas discharged from a thermal power plant, limestone or lime is used as an absorbent and gypsum is recovered as a by-product. At present, the most popular method is the wet lime (stone) / gypsum method. The absorption tower, which is the main equipment in the apparatus for carrying out the wet lime (stone) / gypsum method, is often of the spray type.

In Japanese Patent Laid-Open No. 10-272335, the absorption liquid slurry circulated and supplied from the absorption liquid tank at the lower part of the absorption tower is sprayed from a spray nozzle of a circulation spray header provided at the upper part inside the absorption tower to absorb the absorption liquid. It is a wet flue gas desulfurization method that removes the sulfur oxides and dust in the exhaust gas flowing into the tower, and also removes the mist of the adsorbent entrained in the exhaust gas in the absorption tower. A partition plate in which the gas upflow portion and the gas downflow portion are formed by reversing in the vicinity of the tower top has a ratio of the cross-sectional area of the gas upflow portion to the gas downflow portion of 4: 1 to 2 A wet flue gas desulfurization method and a spray type absorption tower, which are provided at positions such that the flow rate of exhaust gas in the gas downflow section is in the range of 6 to 16 m / s, are described. It

Further, in Japanese Patent Laid-Open No. 2000-15050, the absorbent slurry circulated and supplied by a circulation pump from an absorbent reservoir in the lower part of the absorption tower is a branch spray in a circulating spray header provided in the upper part of the absorption tower. Wet flue gas desulfurization equipment that removes sulfur oxides and dust in the exhaust gas that has been sprayed from the spray nozzle of the pipe and that has flowed into the absorption tower from the gas inlet duct, and that the treated gas is discharged from the gas outlet duct. The spray absorption tower in the flue gas desulfurization apparatus is described in which the circulation spray header is supported by columns provided from the tower bottom to the tower top.

FIG. 8 shows a conventional spray type absorption tower.
And as shown in FIG. 9, the gas upflow section 1 of the absorption tower 1
No. 0 and gas downflow section 12 circulating spray main headers 14 and 16 and sub-header (branch spray pipe) 1
8 and 20 were inserted, and spray nozzles 22 and 24 were arranged on these sub-headers 18 and 20 so that the liquid was uniformly sprayed. In this case, in the gas upflow part, the absorbing liquid is sprayed in the countercurrent direction (downward) with respect to the exhaust gas, and in the gas downflow part, the cocurrent flow direction (downward) or the counterflow direction (upward) with respect to the exhaust gas, or The absorption liquid is sprayed in both the co-current direction and the counter-current direction.
The gas downflow part may not be provided with the main header and the subheader. Reference numerals 26 and 28 denote absorbent liquid circulation pipes, 30 denotes an internal partition plate, 32 denotes an absorbent supply line, and 34
Is a gas inlet duct, 36 is a gas outlet duct, 38 is an absorbing liquid tank, 40 is a mist separating plate, and 42 is an outlet mist eliminator.

[0006]

In this case, the gas superficial velocity is 2.5 m 3 / s to 3.5 m 2 / s in the gas upflow section and 8 in the gas downflow section due to the gas pressure loss (pressure loss).
The range of application was about 12 m / s. This is because the gas velocity in the spray header passage portion is the highest, so that (1) exhaust gas pressure loss in this portion increases. (2) Due to the loading phenomenon (when the gas velocity exceeds a certain value, the liquid holdup gradually increases, and the gas pressure loss rapidly increases), there is the above-mentioned restriction on the applicable exhaust gas velocity.

In the absorption tower of the wet flue gas desulfurization apparatus, cost reduction (both initial cost and running cost) is required, and it is necessary to make the apparatus compact and reduce power consumption. The present invention has been made in view of the above points, and an object of the present invention is to achieve compactness of the device by increasing the exhaust gas flow velocity in the absorption tower, reduce exhaust gas pressure loss, and reduce power consumption. A possible absorption tower structure is to provide a spray type absorption tower of a flue gas desulfurization device in which a circulating spray main header is incorporated into a partition plate inside the absorption tower to form an integrated structure.

[0008]

In order to achieve the above object, a spray type absorption tower of a flue gas desulfurization apparatus of the present invention has an internal partition plate so that openings are formed in the upper and lower parts of the tower. The lower part of the partition plate is a liquid absorbent tank that shuts off the gas flow with a liquid seal, and the gas flow direction is reversed near the top of the tower to form a gas upflow part and a gas downflow part. In a spray absorption tower of a desulfurizer, a circulating spray main header is incorporated into an internal partition plate to form an integrated structure (see FIGS. 1 to 4).

Further, in the spray type absorption tower of the flue gas desulfurization apparatus of the present invention, the inside of the tower is partitioned by an internal partition plate so that openings are formed in the upper and lower parts, and the lower part of the partition plate is liquid-sealed by an absorbent tank. In the spray type absorption tower of the flue gas desulfurization equipment, in which the gas flow is shut off by the gas flow direction and the gas flow direction is reversed near the top of the tower to form the gas upflow section and the gas downflow section Are arranged in multiple stages in the vertical direction of the internal partition plate, the partition member is configured by connecting these main headers with the plate, further, by connecting the sub-header to the main header, the gas upflow section,
Alternatively, the sub-headers are arranged in the gas upflow part and the gas downflow part, and the gas upflow part is in the countercurrent direction to the exhaust gas, or the gas upflow part is in the countercurrent direction to the exhaust gas and the gas downflow is performed. The part is characterized in that the absorbing liquid is sprayed in either the cocurrent direction, the countercurrent direction, or both the cocurrent direction and the countercurrent direction (see FIGS. 1 to 4).

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications. FIG. 1 shows an internal elevation of a spray type absorption tower of a flue gas desulfurization apparatus according to a first embodiment of the present invention, and FIG. 2 shows an internal plane. An internal partition plate 56 is provided so that the inside of the absorption tower 50 has openings 52 and 54 formed in the upper and lower portions.
And the opening 54 at the bottom of the partition plate 56 is made to shut off the gas flow by the liquid in the absorbing liquid tank 38 by the liquid seal, and the gas flow direction is reversed from the upper part to the lower part in the vicinity of the top of the tower, The gas upflow portion 10 and the gas downflow portion 12 are configured to be formed.

In the spray type absorption tower thus constructed, the circulating spray main header 58 is attached to the inner partition plate 56.
Is incorporated to form an integrated structure. Specifically, the circulating spray main headers 58 are arranged in multiple stages in the vertical direction of the internal partition plate 56, and these main headers 58 are connected by plates 60 to form a partition member. Further, the main header 58 has sub-headers (branch spray pipes) 62, 64.
So that the sub-headers 62 and 64 are arranged in the gas upflow section 10 and the gas downflow section 12, respectively, so that the gas downflow section 12 is countercurrent to the exhaust gas flow. In, the absorption liquid is sprayed in the co-current direction. Reference numerals 66 and 68 are spray nozzles, and reference numeral 70 is an absorbent circulating pipe. In the present embodiment, as an example, the gas downflow section sprays the absorbing liquid onto the exhaust gas in a cocurrent direction (downward), but in a countercurrent direction (upward) or in both cocurrent and countercurrent directions. Alternatively, the absorbing liquid may be sprayed on. As described above, in the present embodiment, the circulating spray main header is incorporated into the partition plate inside the absorption tower to form an integral structure, and only the subheader is arranged in the gas passage part of the gas upflow part and the gas downflow part. It is structured.

FIG. 3 shows an internal elevation of a spray type absorption tower of a flue gas desulfurization apparatus according to a second embodiment of the present invention, and FIG.
Indicates an internal plane. In this embodiment, the gas downflow section 12 is not provided with a subheader, and the gas upflow section 10 is provided with the subheader 62 only. Other configurations and operations are similar to those of the first embodiment.

[0013]

EXAMPLES Examples and comparative examples will be shown below to further clarify the features of the present invention. 6 and 7 show a conventional spray type absorption tower as a comparative example, and FIG. 5 shows a spray type absorption tower according to an embodiment of the present invention. The circulation pipes around the spray absorption tower were configured as shown in FIGS. 5, 6 and 7, and when the two were compared, the following results were obtained. 72, 74 and 76 are circulation pumps. Conventional example (comparative example) Example Absorption tower gas flow rate 2.5 m / s to 3.5 m / s 4.5 m / s Exhaust gas pressure loss base (100) (95) Absorption tower diameter base (100) (70 to 80) Number of circulation pumps 4 (in case of Fig. 6) 3

From the above results, in the embodiment, since the gas flow velocity (superficial velocity) can be increased, the absorption column diameter can be reduced and the exhaust gas pressure loss can be reduced, that is, the column can be made compact. It turns out that it can be converted. Further, it can be seen that the number of circulation pumps can be reduced, the circulation piping can be further simplified, and these points can also contribute to downsizing.

[0015]

Since the present invention is configured as described above, it has the following effects. (1) Since the gas passage area of the spray header can be made large (the projected (occupied) area of the spray pipe is small), the exhaust gas in the tower can be made to flow at high speed, and as a result, the absorption tower diameter can be made small and compact. be able to. (2) Since the projected (occupied) area of the spray header portion is small, the exhaust gas pressure loss can be reduced, and the power consumption of the BUF (exhaust gas booster fan) is reduced. (3) Since the partition of the circulating spray main header also serves as a support, no support is required and the internal structure is simplified. (4) When arranging the spray headers in both the gas upflow part and the gas downflow part, it is not necessary to separately arrange the circulating spray main headers in the gas upflow part and the gas downflow part, and the main headers are common. Therefore, the number of circulation pumps can be reduced (1 pump,
1 header). (5) The circulation piping from the circulation pump to the spray header is simplified.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional explanatory view of a spray type absorption tower of a flue gas desulfurization apparatus according to a first embodiment of the present invention.

2 is a cross-sectional explanatory view of the spray type absorption tower shown in FIG.

FIG. 3 is a vertical cross-sectional explanatory view of a spray type absorption tower of a flue gas desulfurization apparatus according to a second embodiment of the present invention.

4 is a cross-sectional explanatory view of the spray type absorption tower shown in FIG.

FIG. 5 is a schematic configuration diagram of a spray type absorption tower used in Examples.

FIG. 6 is a schematic configuration diagram of a spray type absorption tower used in a comparative example.

FIG. 7 is a schematic configuration diagram of a spray type absorption tower used in a comparative example.

FIG. 8 is an explanatory longitudinal sectional view showing an example of a spray type absorption tower of a conventional flue gas desulfurization apparatus.

9 is a cross-sectional explanatory view of the spray type absorption tower shown in FIG.

[Explanation of symbols]

10 Gas Up Flow Part 12 Gas Down Flow Part 14, 16, 58 Circulation Spray Main Header 18, 20, 62, 64 Sub Header (Branch Spray Pipe) 22, 24, 66, 68 Spray Nozzle 26, 28, 70 Absorption Liquid Circulation Pipes 30, 56 Internal partition plate 32 Absorbent supply line 34 Gas inlet duct 36 Gas outlet duct 38 Absorbing liquid tank 40 Mist separation plate 42 Outlet mist eliminator 50 Absorption tower 52, 54 Opening 60 Plate 72, 74, 76 Circulation pump

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4D002 AA02 AC01 BA02 CA01 DA05                       DA11 DA16 FA03                 4D020 AA06 BA02 BA08 BA09 BB03                       CB27 CC06

Claims (2)

[Claims] 1. The inside of the tower is partitioned by an internal partition plate so that openings are formed in the upper part and the lower part, and the lower part of the partition plate is blocked by a liquid seal with an absorbent tank so that the gas flow direction is near the top of the tower. In the spray type absorption tower of the flue gas desulfurization device, which was turned over to form the gas upflow part and the gas downflow part, the circulation spray main header was incorporated into the internal partition plate to make it an integrated structure. A spray type absorption tower for flue gas desulfurization equipment. 2. The inside of the tower is partitioned by an internal partition plate so that openings are formed in the upper part and the lower part, and the lower part of the partition plate is blocked by a liquid seal with a liquid tank, and the gas flow direction is near the top of the tower. In the spray type absorption tower of the flue gas desulfurization device in which the gas upflow section and the gas downflow section are formed by reversing with, the circulating spray main headers are arranged in multiple stages in the vertical direction of the internal partition plate, A partitioning member is formed by connecting the main header of with a plate, and the subheader is connected to the main header, and the subheader is arranged in the gas upflow section or the gas upflow section and the gas downflow section. The exhaust gas in the gas upflow section in the countercurrent direction, or the exhaust gas in the gas upflow section in the countercurrent direction and the gas downflow section in the cocurrent direction. A spray type absorption tower of a flue gas desulfurization device, characterized in that the absorbing liquid is sprayed in both the flow direction, the co-current direction and the countercurrent direction.