Efficient seawater flue gas desulfurization absorption tower

Abstract

A seawater flue gas desulfurization absorption tower, comprising a hollow absorption tower shell (3), further comprising a filler layer (21), a porous structure layer (22) and a spray layer (23) which are arranged in a cavity inside the absorption tower shell (3) and are sequentially connected from bottom to top, and further comprising an absorption tower inlet (1) and an absorption tower outlet (4) which are arranged on the absorption tower shell (3), the absorption tower inlet (1) being arranged below the filler layer (21), and the absorption tower outlet (4) being arranged above the spray layer (23).

Description

A highly efficient seawater flue gas desulfurization absorption tower Technical Field

[0001] The utility model relates to the technical field of flue gas desulfurization, in particular to a high-efficiency seawater flue gas desulfurization absorption tower. Background Art

[0002] Seawater flue gas desulfurization (FGD) utilizes condensed seawater, naturally alkaline at a pH of approximately 7.5 to 8.5, discharged from the condensers of coastal thermal power plants. This process removes sulfur dioxide from the flue gas. The desulfurized seawater is then restored to meet discharge standards. Seawater FGD technology offers advantages such as a short process flow, simple operation, high safety and reliability, and low investment and operating costs, making it the preferred FGD technology for coastal thermal power plants.

[0003] At present, seawater flue gas desulfurization is mainly used for flue gas desulfurization after combustion of low-sulfur coal, and the SO2 concentration in flue gas generally does not exceed 2000 mg / Nm 3 Improving the desulfurization efficiency of seawater flue gas desulfurization (FGD) to adapt it to flue gas with higher SO2 concentrations is a current research hotspot in engineering applications. Optimizing gas-liquid mass transfer is a key research direction for improving seawater FGD efficiency.

[0004] Utility Model Content

[0005] In order to overcome the deficiencies of the prior art, the utility model provides a high-efficiency seawater flue gas desulfurization absorption tower to solve the problems of low desulfurization efficiency in the prior art.

[0006] The technical solution adopted by the present invention to solve the above problems is:

[0007] A high-efficiency seawater flue gas desulfurization absorption tower includes a hollow absorption tower shell, a packing layer, a porous structure layer, and a spray layer, which are connected in sequence from bottom to top and are arranged in the internal cavity of the absorption tower shell. It also includes an absorption tower inlet and an absorption tower outlet arranged on the absorption tower shell, wherein the absorption tower inlet is arranged below the packing layer, and the absorption tower outlet is arranged above the spray layer.

[0008] As a preferred technical solution, the bottom of the packing layer is 0-3000 mm away from the upper edge of the absorption tower inlet.

[0009] As a preferred technical solution, the height of the packing layer is 3000-6000 mm.

[0010] As a preferred technical solution, the packing layer is a structure formed by random stacking of packings.

[0011] As a preferred technical solution, the bottom of the porous structure layer is 0-3000 mm away from the upper edge of the filler layer.

[0012] As a preferred technical solution, the bottom of the porous structure layer is 1000-3000 mm away from the upper edge of the spray layer.

[0013] As a preferred technical solution, the opening diameter of the porous structure layer is 30-70 mm.

[0014] As a preferred technical solution, the porosity of the porous structure layer is 10%-60%.

[0015] As a preferred technical solution, the porous structure layer is a plate-like structure.

[0016] As a preferred technical solution, it also includes a demister arranged in the internal cavity of the absorption tower shell, and the demister is arranged below the absorption tower outlet and above the spray layer.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The utility model has higher desulfurization efficiency and lower SO2 emission concentration, which is lower than the ultra-low emission limit. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG1 is a schematic structural diagram of the present utility model.

[0020] The marks and their corresponding names in the accompanying drawings are: 1. absorption tower inlet, 21. packing layer, 22. porous structure layer, 23. spray layer, 24. demister, 4. absorption tower outlet. DETAILED DESCRIPTION

[0021] 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.

[0022] Example 1

[0023] As shown in FIG1 , the utility model provides a seawater flue gas desulfurization absorption tower having a higher desulfurization efficiency than the existing spray tower and packed tower technologies.

[0024] Above the flue at the absorption tower inlet 1, a packing layer 21, a porous structure layer 22 (the porous structure layer 22 has a plurality of holes, and the porous structure layer 22 is preferably a plate-shaped structure), and a spray layer 23 are arranged in sequence from bottom to top.

[0025] The height of the packing layer 21 is 3000-6000 mm. The packing layer 21 is formed by random stacking of regular or irregular packings. The bottom of the packing layer 21 is 0-3000 mm away from the upper edge of the flue at the absorption tower inlet 1.

[0026] The porous structure layer 22 is arranged between the packing layer 21 and the spray layer 23 . The bottom of the porous structure layer 22 is 0-3000 mm away from the upper edge of the packing layer 21 and 1000-3000 mm away from the upper edge of the spray layer 23 .

[0027] The porous structure layer 22 has an opening diameter of 30-70 mm and an opening rate of 10%-60%.

[0028] The gas-liquid contact mass transfer of the seawater flue gas desulfurization absorption tower mainly adopts spray tower and packed tower technology. The spray tower has a small tower diameter, high flue gas flow rate, strong gas-liquid mass transfer effect, and high desulfurization efficiency. The packed tower has a large tower diameter, low flue gas flow rate, and the flue gas stays in the tower for a long time, which has a high desulfurization efficiency. Combining the advantages of spray tower and packed tower technology, this utility model develops a more efficient seawater flue gas desulfurization absorption tower, which improves the seawater desulfurization efficiency to adapt to flue gas desulfurization with higher SO2 concentration, and at the same time SO2 reaches or exceeds the ultra-low emission limit of 35mg / Nm 3 (6% O2, dry).

[0029] Example 2

[0030] As shown in FIG1 , as a further optimization of Example 1, based on Example 1, this embodiment further includes the following technical features:

[0031] The seawater flue gas desulfurization absorption tower consists of an absorption tower inlet 1, a packing layer 21, a porous structure layer 22, a spray layer 23, a demister 24, a tower shell 3 and an absorption tower outlet 4.

[0032] The packing layer 21 is arranged between the absorption tower inlet 1 and the porous structure layer 22, with its bottom 0-3000 mm away from the upper edge of the absorption tower inlet 1. The packing layer 21 has a height of 3000-6000 mm and is composed of regular or irregular packings.

[0033] The porous structure layer 22 is arranged between the packing layer 21 and the spray layer 23 . The bottom of the porous structure layer 22 is 0-3000 mm away from the upper edge of the packing layer 21 and 1000-3000 mm away from the upper edge of the spray layer 23 .

[0034] The porous structure layer 22 has an opening diameter of 30-70 mm and an opening rate of 10%-60%.

[0035] Taking a 350MW coal-fired unit as an example, the flue gas volume is 1500000Nm 3 / h, flue gas temperature 145℃, flue gas SO2 concentration up to 3000mg / Nm 3 (6% O2, dry), using seawater desulfurization process, the absorption tower supplies 20000m 3 / h.

[0036] Comparative Example 1: According to the conventional spray tower design, the absorption tower diameter is 14000mm, the flue gas flow rate in the tower is 3.0m / s. The absorption tower spray layer is designed to have 3 layers, each spray layer corresponds to a seawater pump, and the seawater pump flow rate is 6700m 3 / h, a tray is set between the bottom layer of the absorption tower spray layer and the inlet flue. The desulfurization efficiency of the absorption tower is 97.3%, and the net flue gas SO2 emission concentration is 81mg / Nm 3 The absorption zone resistance of the absorption tower is 1350Pa.

[0037] Comparative Example 2: Using packed tower technology, the absorption tower has a diameter of 16,500 mm and a flue gas velocity of 2.2 m / s. The packing layer is 4,000 mm high and uses PP snowflake-shaped packing. The bottom is 1,000 mm from the top of the absorption tower inlet flue and 2,500 mm from the spray layer. The absorption tower is supplied with seawater by three pumps (two in operation and one in reserve), with a flow rate of 10,000 m / s per pump. 3 / h. The desulfurization efficiency of the absorption tower is 97%, and the net flue gas SO2 emission concentration is 90mg / Nm 3 The absorption zone resistance of the absorption tower is 1300Pa.

[0038] The absorption tower adopts this new model, with a diameter of 16500mm and a flue gas velocity of 2.2m / s. The packing layer is 4000mm high and made of PP snowflake-shaped packing. The bottom is 1000mm away from the top of the absorption tower inlet flue and 1000mm away from the porous structure layer. The bottom of the porous structure layer is 2200mm away from the top of the spray layer. The absorption tower is supplied with seawater by three pumps (two in operation and one in reserve). The flow rate of a single seawater pump is 10000m 3 / h, the seawater sprayed by the spray layer forms a 50-300mm high boiling liquid holding layer on the porous structure layer, enhancing the gas-liquid mass transfer effect and improving the desulfurization efficiency. The desulfurization efficiency of the absorption tower is 99%, and the net flue gas SO2 emission concentration is 30mg / Nm 3 , better than the ultra-low emission limit of 35mg / Nm 3 The absorption zone resistance of the absorption tower is 1500 Pa. Comparison shows that with the same amount of seawater sprayed, the desulfurization efficiency of the utility model is higher and the SO2 emission concentration is lower, which is lower than the ultra-low emission limit.

[0039] As described above, the present invention can be implemented well.

[0040] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Based on the technical essence of the present invention and within the spirit and principles of the present invention, any simple modification, equivalent replacement and improvement of the above embodiment shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. An efficient seawater flue gas desulfurization absorption tower, characterized in that: The invention comprises a hollow absorption tower shell (3), a packing layer (21), a porous structure layer (22), and a spray layer (23) which are arranged in the inner cavity of the absorption tower shell (3) and are connected in sequence from bottom to top, and an absorption tower inlet (1) and an absorption tower outlet (4) which are arranged on the absorption tower shell (3), wherein the absorption tower inlet (1) is arranged below the packing layer (21), and the absorption tower outlet (4) is arranged above the spray layer (23).

2. The efficient seawater flue gas desulfurization absorption tower according to claim 1, characterized in that: The bottom of the packing layer (21) is 0-3000 mm away from the upper edge of the absorption tower inlet (1).

3. The efficient seawater flue gas desulfurization absorption tower according to claim 1, characterized in that: The height of the packing layer (21) is 3000-6000 mm.

4. The efficient seawater flue gas desulfurization absorption tower according to claim 1, characterized in that: The packing layer (21) is a structure formed by random packing.

5. The efficient seawater flue gas desulfurization absorption tower according to claim 1, characterized in that: The bottom of the porous structure layer (22) is 0-3000 mm away from the upper edge of the filler layer (21).

6. The efficient seawater flue gas desulfurization absorption tower according to claim 1, characterized in that: The bottom of the porous structure layer (22) is 1000-3000 mm away from the upper edge of the spray layer (23).

7. The efficient seawater flue gas desulfurization absorption tower according to claim 1, characterized in that: The opening diameter of the porous structure layer (22) is 30-70 mm.

8. The high-efficiency seawater flue gas desulfurization absorption tower according to claim 1, characterized in that: The open porosity of the porous structure layer (22) is 10%-60%.

9. The high-efficiency seawater flue gas desulfurization absorption tower according to claim 1, characterized in that: The porous structure layer (22) is a plate-like structure.

10. A high-efficiency seawater flue gas desulfurization absorption tower according to any one of claims 1 to 9, characterized in that: It also includes a demister (24) arranged in the inner cavity of the absorption tower shell (3); the demister (24) is arranged below the absorption tower outlet (4) and above the spray layer (23).

Images