Efficient SDA semi-dry flue gas desulfurization system

Abstract

The efficient SDA semi-dry flue gas desulfurization system comprises a desulfurization absorption tower and a bag-type dust collector which are connected in sequence, and an SDA slurry atomizer is arranged at an air inlet in the upper portion of the desulfurization absorption tower; a lower air inlet of the desulfurizing absorption tower is sequentially divided into an inlet section, an acceleration section and a diffusion section; the inlet section is provided with a material returning opening which is connected with an ash outlet of the bag-type dust collector; the ash outlet of the bag-type dust collector is also provided with an ash conveying bypass which is connected with the desulfurized ash bin; a water spraying mechanism is arranged on the desulfurizing absorption tower and the diffusion section, and an ash discharging opening is formed in the bottom of the desulfurizing absorption tower and is connected with the desulfurized ash bin. According to the invention, a desulfurizing agent dry circulation method is adopted to replace slurry circulation in a traditional SDA semi-dry desulfurization process, water consumption and flue gas temperature drop in the desulfurization process are greatly reduced, the concentration of the desulfurizing agent in the desulfurization absorption tower is improved, and a water spraying mechanism is arranged in the dry circulation process, so that the desulfurization efficiency of the circulating desulfurizing agent is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental engineering, and particularly to an efficient SDA semi-dry flue gas desulfurization system. Background Art

[0002] Semi-dry desulfurization technology is a relatively widely used flue gas SO2 treatment technology at present. Among them, the rotating spray semi-dry method (abbreviated as SDA) is one of them, which has the advantages of mature process and good adaptability. The desulfurizer of the traditional SDA semi-dry desulfurization system, including the recirculation system, needs to be made into slurry, resulting in a large water consumption problem. Especially in the recirculation system, since the mixed material after desulfurization is used, impurities such as calcium sulfate are difficult to dissolve, which is easy to cause corrosion and blockage problems. At the same time, in order to prevent the problem of "bag sticking" of the back-end bag filter, the temperature of the flue gas after desulfurization needs to be more than 15°C higher than the dew point. Therefore, the temperature drop caused by the large water consumption limits the concentration of the desulfurizer sprayed into the tower. Under the condition of high SO2 flue gas, it is difficult to meet the ultra-low emission requirements.

[0003] Patent CN 211936362 U discloses a multi-point powder spraying desulfurization system based on the SDA method, which circularly arranges powder spraying points at different heights in the tower for the recycled desulfurizer. However, the device is complex, has high requirements for the flow field design, and is easy to cause problems such as desulfurizer wall sticking and uneven mixing. Moreover, the desulfurization reaction needs to form an ionic reaction through the water film on the desulfurizer to achieve a higher efficiency. Simply adding dry powder cannot effectively improve the desulfurizer utilization rate and desulfurization efficiency, resulting in ineffective energy waste. Summary of the Invention

[0004] To overcome the above defects, the purpose of the present invention is to provide an efficient SDA semi-dry flue gas desulfurization system that can reduce water consumption and flue gas temperature drop and improve desulfurization efficiency.

[0005] To achieve the above purpose, the efficient SDA semi-dry flue gas desulfurization system of the present invention includes a desulfurization absorption tower (1) and a bag filter (2) connected in sequence. An SDA slurry atomizer (101) is provided at the upper air inlet of the desulfurization absorption tower (1).

[0006] The lower air inlet of the desulfurization absorption tower (1) is sequentially divided into an inlet section (102), an acceleration section (103), and a diffusion section (104). The inlet section (102) is provided with a return port, which is connected to the ash outlet of the bag filter (2).

[0007] The ash outlet of the bag filter (2) is also provided with an ash conveying bypass connected to a desulfurization ash bin (5).

[0008] A water spraying mechanism (6) is provided on the diffusion section (104) of the desulfurization absorption tower (1). A dust discharge port is provided at the bottom of the desulfurization absorption tower (1) and is connected to the desulfurization ash bin (5).

[0009] Further, the SDA slurry atomizer is connected to a gravity storage tank (3) through a pipeline.

[0010] Further, the gravity storage tank (3) is connected to a desulfurizer slurry tank (4) through a pipeline.

[0011] Further, adjustable baffle gates and flow meters are provided on the flue ducts of the upper air inlet and the lower air inlet of the desulfurization absorption tower (1).

[0012] Further, the acceleration section (103) adopts a Venturi accelerator structure, with a Venturi inlet flow rate of 20 - 30 m / s and a throat flow rate of 30 - 50 m / s.

[0013] Further, the outlet flow rate of the diffusion section (104) is 5 - 10 m / s.

[0014] Further, the distance between the outlet of the diffusion section (104) and the bottom of the SDA slurry atomizer (101) is taken as 1.5 times the diameter of the desulfurization absorption tower (1).

[0015] Further, the water spraying mechanism (6) adopts one of the double-fluid spray guns or high-pressure reflux spray guns; a flow control valve and an instrument are provided on the pipeline of the water spraying mechanism (6).

[0016] The present invention has the following advantages:

[0017] 1). For the high-efficiency SDA semi-dry flue gas desulfurization system of the present invention, the method of dry circulation of the desulfurizer is adopted to replace the slurry circulation in the traditional SDA semi-dry desulfurization process, greatly reducing the water consumption and the temperature drop of the flue gas during the desulfurization process, increasing the desulfurizer concentration in the desulfurization absorption tower, and a water spraying mechanism is set during the dry circulation process to improve the desulfurization efficiency of the circulating desulfurizer.

[0018] 2). For the high-efficiency SDA semi-dry flue gas desulfurization system of the present invention, a Venturi acceleration section is provided on the pipeline of the lower air inlet of the desulfurization absorption tower. On the one hand, it strengthens the mixing uniformity of the circulating desulfurizer and the flue gas. On the other hand, the relatively high flow rate design enables the desulfurizer to form a certain turbulent zone above the Venturi outlet, prolonging the contact time between the flue gas and the desulfurizer and further improving the desulfurization efficiency.

[0019] 3) In the high-efficiency SDA semi-dry flue gas desulfurization system of the present invention, due to the use of the method of dry circulation of desulfurizer, the SDA slurry atomizer only uses fresh desulfurizer slurry, the equipment selection size will be greatly reduced, the process of the pulping system will be greatly simplified, the investment cost will be reduced, and the problems of blockage and corrosion in the traditional slurry circulation will be effectively avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall process of the system of the present invention;

[0021] In the figure, 1 - desulfurization absorption tower, including 101 - SDA slurry atomizer, 102 - inlet section, 103 - acceleration section, 104 - diffusion section; 2 - bag filter, 3 - gravity storage tank, 4 - desulfurizer slurry tank, 5 - desulfurization ash bin, 6 - water spraying mechanism. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The embodiments of the present invention will be described in detail below with reference to the drawings.

[0023] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0024] The terms "first" and "second" are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0025] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a direct connection, or an indirect connection through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] The present invention provides an efficient SDA semi-dry flue gas desulfurization system, which at least includes a desulfurization absorption tower (1) and a bag filter (2) connected in sequence. The upper air inlet of the desulfurization absorption tower (1) is connected to an SDA slurry atomizer (101), and the SDA slurry atomizer (101) is connected to a gravity storage tank (3) and a desulfurizer slurry tank (4) in sequence; the lower air inlet of the desulfurization absorption tower (1) is divided into an inlet section (102), an acceleration section (103), and a diffusion section (104) in sequence; the inlet section (102) is provided with a return port, which is connected to the ash outlet of the bag filter (2); the ash outlet of the bag filter (2) is also provided with an ash conveying bypass connected to a desulfurization ash bin (5); a water spraying mechanism (6) is provided on the diffusion section (104) of the desulfurization absorption tower (1), and a ash discharge port is provided at the bottom of the desulfurization absorption tower (1), which is connected to the desulfurization ash bin (5).

[0027] Embodiment

[0028] As an embodiment of the present invention, refer to Figure 1 , including a desulfurization absorption tower (1) and a bag filter (2) connected in sequence. The upper air inlet of the desulfurization absorption tower (1) is connected to an SDA slurry atomizer (101), and the SDA slurry atomizer (101) is connected to a gravity storage tank (3) and a desulfurizer slurry tank (4) in sequence; the lower air inlet of the desulfurization absorption tower (1) is divided into an inlet section (102), an acceleration section (103), and a diffusion section (104) in sequence; the inlet section (102) is provided with a return port, which is connected to the ash outlet of the bag filter (2); the ash outlet of the bag filter (2) is also provided with an ash conveying bypass connected to a desulfurization ash bin (5); a water spraying mechanism (6) is provided on the diffusion section (104) of the desulfurization absorption tower (1), and a ash discharge port is provided at the bottom of the desulfurization absorption tower (1), which is connected to the desulfurization ash bin (5).

[0029] Adjustable baffle gates and flow meters are provided on the flue ducts of the upper air inlet and the lower air inlet of the flue gas entering the desulfurization absorption tower (1). The acceleration section (103) adopts a Venturi accelerator structure, with a Venturi inlet flow rate of 20 - 30 m / s and a throat flow rate of 30 - 50 m / s; the outlet flow rate of the diffusion section (104) is 5 - 10 m / s. The distance between the outlet of the diffusion section (104) and the bottom of the SDA slurry atomizer (101) is taken as 1.5 times the diameter of the desulfurization absorption tower (1). The water spraying mechanism (6) adopts one of the double-fluid spray gun or high-pressure return spray gun methods. A flow control valve and instrument are provided on the pipeline of the water spraying mechanism (6).

[0030] The present invention has been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the art. Many other changes and modifications made without departing from the concept and scope of the present invention should be regarded as within the protection scope of the present invention.

[0031] In the description of this specification, the specific features, structures, materials, or characteristics may be combined in any one or more embodiments or examples in a suitable manner.

[0032] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An efficient SDA semi-dry flue gas desulfurization system, characterized in that It includes a desulfurization absorption tower (1) and a bag filter (2) connected in sequence. An SDA slurry atomizer (101) is provided at the upper air inlet of the desulfurization absorption tower (1). The lower air inlet of the desulfurization absorption tower (1) is sequentially divided into an inlet section (102), an acceleration section (103), and a diffusion section (104). A return material port is provided in the inlet section (102), which is connected to the ash outlet of the bag filter (2). An ash conveying bypass is also provided at the ash outlet of the bag filter (2) and is connected to a desulfurization ash bin (5). A water spraying mechanism (6) is provided on the diffusion section (104) of the desulfurization absorption tower (1). A ash discharge port is provided at the bottom of the desulfurization absorption tower (1) and is connected to the desulfurization ash bin (5).

2. The high-efficiency SDA semi-dry flue gas desulfurization system according to claim 1, wherein The SDA slurry atomizer is connected to a gravity storage tank (3) through a pipeline.

3. The high-efficiency SDA semi-dry flue gas desulfurization system according to claim 2, wherein, The gravity storage tank (3) is connected to a desulfurizer slurry tank (4) through a pipeline.

4. The high-efficiency SDA semi-dry flue gas desulfurization system according to claim 1, characterized in that, Adjustable baffle doors and flow meters are provided on the flue ducts of the upper air inlet and the lower air inlet of the desulfurization absorption tower (1).

5. The high-efficiency SDA semi-dry flue gas desulfurization system according to claim 1, wherein The acceleration section (103) adopts a Venturi accelerator structure, with a Venturi inlet flow rate of 20 - 30 m / s and a throat flow rate of 30 - 50 m / s.

6. The high-efficiency SDA semi-dry flue gas desulfurization system according to claim 1, characterized in that, The outlet flow rate of the diffusion section (104) is 5 - 10 m / s.

7. The high-efficiency SDA semi-dry flue gas desulfurization system according to claim 1, characterized in that, The distance between the outlet of the diffusion section (104) and the bottom of the SDA slurry atomizer (101) is 1.5 times the diameter of the desulfurization absorption tower (1).

8. The high-efficiency SDA semi-dry flue gas desulfurization system according to claim 1, characterized in that, The water spraying mechanism (6) adopts one of the double-fluid spray gun or high-pressure return spray gun methods; a flow control valve and instrument are provided on the pipeline of the water spraying mechanism (6).

Images