Seawater flue gas desulfurization absorption tower

Abstract

The utility model relates to the technical field of seawater flue gas desulfurization, and discloses a seawater flue gas desulfurization absorption tower which comprises an absorption tower outlet part, a demister section, a demister reducing section, an absorption section and a flue gas inlet which are sequentially communicated from top to bottom. According to the utility model, the problems of high emission concentration of SO2 and dust in flue gas and the like in the prior art are solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to seawater flue gas desulfurization technical field, specifically a seawater flue gas desulfurization absorption tower. BACKGROUND

[0002] Seawater flue gas desulfurization utilizes the circulating cooling seawater with the pH value of about 7.5-8.5 and the natural alkalinity discharged by the condenser of the seaside thermal power plant as the desulfurizer to remove SO2 in the flue gas, and restores the water quality of the seawater after removing SO2 in the flue gas, and discharges according to the standard. The seawater flue gas desulfurization technology has the advantages of short process flow, simple operation, high safety and reliability, low investment cost and operation cost, and is the preferred technology for flue gas desulfurization of the seaside thermal power plant.

[0003] At present, the flue gas pollutants are required to be lower than the ultra-low emission limit value, that is, to meet the requirements of SO2 concentration lower than 35mg / Nm 3 (6%O2, dry), and dust concentration lower than 10mg / Nm 3 (6%O2, dry). Some seaside thermal power plants have put forward more stringent requirements for the flue gas pollutant emission of the seawater flue gas desulfurization process, such as SO2 concentration lower than 5mg / Nm 3 (6%O2, dry), and dust concentration lower than 2mg / Nm 3 (6%O2, dry). For the seawater flue gas desulfurization process, the flue gas flow rate in the absorption tower is relatively low, generally about 1.4-3m / s, the flue gas stays in the tower for a long time, the desulfurization efficiency is relatively high, the SO2 concentration of the flue gas can be lower than 5mg / Nm 3 (6%O2, dry), and it is also the existing absorption tower that the low flue gas flow rate leads to low mist droplet removal rate of the demister, so that the dust removal efficiency of the absorption tower is not high, and the dust emission concentration is difficult to be lower than 2mg / Nm 3 (6%O2, dry). SUMMARY

[0004] In order to overcome the defects of the prior art, the utility model provides a seawater flue gas desulfurization absorption tower, which solves the problems of high SO2 and dust emission concentration in the prior art.

[0005] The utility model adopts the technical scheme of solving the above problems:

[0006] A seawater flue gas desulfurization absorption tower, comprising an absorption tower outlet portion, a demister section, a demister variable diameter section, an absorption section and a flue gas inlet portion which are sequentially connected from top to bottom.

[0007] As a preferred technical scheme, the angle between the shell of the demister variable diameter section and the cross section of the seawater flue gas desulfurization absorption tower is 35°-60°.

[0008] As a preferred technical scheme, the demister used in the demister section is a ridge type demister.

[0009] As a preferred technical scheme, the demister used in the demister section is a plate type demister.

[0010] As a preferred technical scheme, the outlet part of the absorption tower comprises an absorption tower outlet, an absorption tower outlet reducer, and the absorption tower outlet, the absorption tower outlet reducer and the demister section are sequentially communicated from top to bottom.

[0011] As a preferred technical scheme, the angle β between the shell of the absorption tower outlet reducer and the cross section of the seawater flue gas desulfurization absorption tower is 35°-45°.

[0012] As a preferred technical scheme, the absorption section comprises a spray layer and a filler layer arranged from top to bottom.

[0013] As a preferred technical scheme, the height of the filler layer is 3000-6000mm.

[0014] As a preferred technical scheme, the height of the filler layer is 3000-6000mm.

[0015] As a preferred technical scheme, the height of the filler layer is 3000-6000mm.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] The present application improves the desulfurization and dust removal efficiency, and can meet the more stringent emission limit value than the ultra-low emission (SO2 concentration is lower than 35mg / Nm 3 (6%O2, dry), dust concentration is lower than 10mg / Nm 3 (6%O2, dry)) to make the flue gas SO2 concentration lower than 5mg / Nm 3 (6%O2, dry), dust concentration is lower than 2mg / Nm 3 (6%O2, dry). BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The present application has the following beneficial effects:

[0019] The marks in the drawings and their corresponding names are as follows: 1-absorption tower flue gas inlet, 2-absorption section, 21-filler layer, 22-spray layer, 3-demister reducer, 4-demister section, 5-absorption tower outlet reducer, 6-absorption tower outlet. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below in conjunction with the embodiments and drawings, but the implementation manner of the present invention is not limited thereto.

[0021] Example 1

[0022] like Figure 1 As shown, the utility model provides a seawater flue gas desulfurization absorption tower with flue gas SO2 and dust emission concentrations lower than the ultra-low emission limit.

[0023] Above the absorption tower inlet flue, an absorption section, a demister reducing section, a demister section, an absorption tower outlet reducing section, and an absorption tower outlet are arranged in sequence from bottom to top.

[0024] The installation of a variable diameter demister section increases the flue gas flow velocity, mist droplet removal efficiency, and dust removal efficiency. The angle α between the demister section shell and the tower cross section is 35°-60°. The flue gas flow velocity in the tower cross section of the demister section is 3.0m / s-4.0m / s, and the demister face velocity is 3.5m / s-5.0m / s. The demister can be a ridge-type or plate-type demister.

[0025] The angle β between the shell of the reducing section at the outlet of the absorption tower and the cross section of the tower is 35°-45°, and the flue gas flow velocity at the outlet of the absorption tower is 15m / s.

[0026] The absorption section is provided with a packing layer and a spray layer from bottom to top, and the flue gas flow velocity of the tower section of the absorption section is 1.4m / s-3m / s.

[0027] The packing layer is 3000-6000mm high and is formed by stacking regular or irregular packing. The bottom of the packing layer is 0-3000mm away from the upper edge of the absorption tower inlet flue, and the upper edge of the packing layer is 1000-3000mm away from the center of the spray layer. The spray layer (22) is composed of nozzles and spray pipes.

[0028] Improve desulfurization and dust removal efficiency to meet ultra-low emissions (SO2 concentration below 35mg / Nm 3 (6% O2, dry), dust concentration is less than 10mg / Nm 3 (6% O2, dry)) More stringent emission limits, making the flue gas SO2 concentration below 5mg / Nm 3 (6% O2, dry), dust concentration is less than 2mg / Nm 3 (6% O2, dry).

[0029] Example 2

[0030] like Figure 1 As shown, as a further optimization of Example 1, based on Example 1, this embodiment also includes the following technical features:

[0031] An ultra-low emission seawater flue gas desulfurization absorption tower is composed of a flue gas inlet 1, an absorption section 2, a demister variable diameter section 3, a demister section 4, an absorption tower outlet variable diameter section 5 and an absorption tower outlet 6, and the absorption section 2 is composed of a filler layer 21 and a spraying layer 22.

[0032] By arranging the demister variable diameter section 3, the flue gas flow rate of the demister section 4 is increased, the demister droplet removal efficiency is improved, and the dust removal efficiency is improved. The shell of the demister variable diameter section 3 and the tower cross section have an included angle α of 35°-60°, the tower cross section flue gas flow rate of the demister section 4 is 3.0 m / s-4.0 m / s, the demister surface flow rate is 3.5 m / s-5.0 m / s, and the demister can adopt a ridge type or a plate type demister.

[0033] The shell of the absorption tower outlet variable diameter section 5 and the tower cross section have an included angle β of 35°-45°, and the flue gas flow rate of the absorption tower outlet 6 is 15 m / s.

[0034] The absorption section 2 is provided with the filler layer 21 and the spraying layer 22 from bottom to top, and the tower cross section flue gas flow rate of the absorption section 2 is 1.4 m / s-3 m / s.

[0035] The filler layer 21 has a height of 3000-6000 mm, and is formed by stacking regular or irregular fillers. The filler layer 21 is 0-3000 mm away from the upper edge of the flue duct of the flue gas inlet 1 of the absorption tower at the bottom, the spraying layer 22 is composed of nozzles and spraying pipelines, and the upper edge of the filler layer 21 is 1000-3000 mm away from the center of the spraying pipeline of the spraying layer 22.

[0036] Taking a 1000 MW coal-fired unit as an example, the flue gas volume is 3050000 Nm 3 / h, the flue gas temperature is 75℃, the flue gas SO2 concentration is 1700 mg / Nm 3 (6% O2, dry), and the dust concentration is 15 mg / Nm 3 (6% O2, dry). The seawater desulfurization process is adopted, the seawater supply of the absorption tower is 24000 m 3 / h, and the SO2 concentration of the clean flue gas after desulfurization is ≤5 mg / Nm 3 (6% O2, dry), and the dust concentration is ≤2 mg / Nm 3 (6% O2, dry).

[0037] The absorption tower has a diameter of 27 m, the tower cross section flue gas flow rate of the absorption section is 1.6 m / s, the absorption section has a height of 7 m, the filler layer has a height of 4 m, the demister variable diameter section has an angle α of 40°, the tower body diameter of the demister section is 18 m, the tower cross section flue gas flow rate of the demister section is 3.6 m / s, the demister adopts a three-stage ridge type, and the demister surface flow rate is 4.0 m / s. The absorption tower outlet variable diameter section has an angle β of 38°, the absorption tower outlet has a diameter of 8.8 m, and the flue gas flow rate is 15 m / s.

[0038] The utility model discloses, as described above, can better realize.

[0039] The above is only the preferred embodiment of the utility model, and does not limit the utility model in any form, and according to the technical essence of the utility model, any simple modification, equivalent replacement and improvement of the above embodiment within the spirit and principle of the utility model still belong to the protection scope of the utility model technical scheme.

Claims

1. A seawater flue gas desulfurization absorption tower, characterized in that, The seawater flue gas desulfurization tower comprises, from top to bottom, an absorption tower outlet part, a demister section (4), a demister reducing section (3), an absorption section (2), and a flue gas inlet (1) in sequence; the included angle β between the shell of the absorption tower outlet reducing section (5) and the cross section of the seawater flue gas desulfurization tower is 35°-45°; the included angle α between the shell of the demister reducing section (3) and the cross section of the seawater flue gas desulfurization tower is 35°-60°; the absorption section (2) comprises, from top to bottom, a spraying layer (22) and a filler layer (21); the height of the filler layer (21) is 3000-6000 mm; the height from the bottom of the filler layer (21) to the upper edge of the flue gas inlet (1) of the absorption tower is 0-3000 mm; and the height from the upper edge of the filler layer (21) to the center of the spraying layer (22) is 1000-3000 mm.

2. A seawater FGD absorption tower according to claim 1, characterized in that, The demister used in the demister section (4) is a ridge type demister.

3. A seawater FGD absorption tower according to claim 1, characterized in that, The demister used in the demister section (4) is a plate type demister.

4. A seawater FGD absorption tower according to claim 1, characterized in that, The absorption tower outlet part comprises an absorption tower outlet (6) and an absorption tower outlet reducing section (5), and the absorption tower outlet (6), the absorption tower outlet reducing section (5), and the demister section (4) are in sequence from top to bottom.

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