Limestone wet desulfurization oxidation air duct system

Abstract

The present application relates to the technical fields of wet flue gas desulfurization, in particular to a limestone wet flue gas desulfurization oxidizing air pipeline system, which comprises an oxidizing air fan and a plurality of oxidizing air main pipes, the plurality of oxidizing air main pipes are connected to the oxidizing air fan through a connecting pipe after being connected in parallel, the oxidizing air main pipes pass through the tower wall of an absorption tower and are located in the absorption tower, the oxidizing air main pipes are inclined downward, a plurality of oxidizing air branch pipes are uniformly distributed on the oxidizing air main pipes, the oxidizing air branch pipes are inclined downward away from the jet end of the oxidizing air main pipes, and a plurality of air outlets are arranged on the lower side walls of the oxidizing air main pipes and the oxidizing air branch pipes. Through the structural design, the present application realizes on-line descaling, prevents slurry from flowing back into the pipeline, uniformly diffuses the oxidizing air, guarantees stable operation of the system, improves the desulfurization efficiency and reduces the maintenance cost.

Description

Technical Field

[0001] This invention relates to the field of wet flue gas desulfurization technology, and in particular to a limestone wet desulfurization oxidation air duct system. Background Technology

[0002] In wet flue gas desulfurization systems, calcium sulfite and calcium bisulfite in the limestone slurry are oxidized to calcium sulfate by oxygen in the oxidizing air within the slurry pool of the absorber, ultimately forming a byproduct gypsum slurry. This gypsum slurry is then pumped to the gypsum dewatering system. Currently, many limestone-gypsum wet flue gas desulfurization systems employ a pipeline network, consisting of one or more horizontal main pipes and multiple horizontal branch pipes.

[0003] Because the slurry in the absorption tower has a high solids content, liquid easily accumulates inside the oxidation air ducts, forming large areas of gypsum scale. Furthermore, the slurry's repeated fluctuations and intrusion, combined with evaporation and crystallization, form hard, ring-shaped scale that gradually narrows in diameter. This scale cannot be handled while the unit is running; after shutdown, the pipes need to be cut for inspection and re-corrosion treatment, which is time-consuming and difficult to resolve. Blockage in the oxidation air ducts of the absorption tower: First, it limits the output of the oxidation fan, easily causing motor damage; insufficient oxidation airflow in the absorption tower leads to poor slurry quality, increased calcium sulfite content in the gypsum, affecting desulfurization efficiency and the quality of the by-product gypsum; blockage also worsens the distribution of oxidation air, leading to insufficient oxidation in localized areas within the absorption tower, resulting in difficult-to-treat mixed scale on all internal components (such as the agitator and spray layer); in severe cases, it can even cause slurry poisoning in the absorption tower, causing unit shutdown. Summary of the Invention

[0004] The purpose of this invention is to provide a limestone wet desulfurization oxidation air duct system that can solve the above-mentioned technical problems and reduce the probability of duct blockage during daily operation.

[0005] This invention provides a limestone wet desulfurization oxidation air pipeline system, including an oxidation blower and several oxidation air main pipes. The several oxidation air main pipes are connected in parallel and connected to the oxidation blower through connecting pipes. The oxidation air main pipes pass through the wall of the absorption tower and are located inside the absorption tower. The oxidation air main pipes are inclined downwards. Several oxidation air branch pipes are evenly distributed on the oxidation air main pipes. The nozzle ends of the oxidation air branch pipes away from the oxidation air main pipes are inclined downwards. Several air outlet holes are provided on the lower side walls of the oxidation air main pipes and the oxidation air branch pipes.

[0006] Preferably, the nozzle end of the oxidation air branch pipe has a conical nozzle structure.

[0007] Preferably, the diameter of the air outlet on the oxidation air branch pipe gradually increases along the airflow direction.

[0008] Preferably, the angle between the main oxidation air pipe and the horizontal plane is 10-15°, and the angle between the branch oxidation air pipe and the horizontal plane is 15-25°.

[0009] Preferably, the oxidation air branch pipes on adjacent oxidation air main pipes are arranged alternately.

[0010] Preferably, the absorption tower is provided with several support beams, and the support beams are fixedly connected to the oxidation air main pipe by a bracket.

[0011] Preferably, the top of the support beam is provided with a segmentation refiner, which is a mesh structure.

[0012] Preferably, the segmentation refiner includes a plurality of transverse slices and longitudinal slices, wherein the transverse slices and the longitudinal slices are arranged perpendicularly to each other to form a mesh structure.

[0013] Preferably, the connecting pipe is connected to a flushing water pipe, and the flushing water pipe is connected to an external water pump.

[0014] Preferably, the connecting pipe is provided with a first valve, the flushing water pipe is located between the first valve and the oxidation air main pipe, and the flushing water pipe is provided with a second valve at one end near the connecting pipe.

[0015] Beneficial effects: Through structural design, this invention achieves descaling without shutting down the system, prevents slurry backflow into the pipeline, and enables uniform diffusion of oxidation air, ensuring stable system operation, improving desulfurization efficiency and reducing maintenance costs.

[0016] This invention adjusts the tilt of the oxidation air main pipe and oxidation air branch pipes to effectively prevent slurry backflow and reduce the probability of pipe blockage during daily operation; it also installs flushing water pipes to flush the oxidation air main pipe and oxidation air branch pipes, achieving descaling and preventive maintenance without shutting down the system; and it incorporates a segmentation refiner to increase the contact area between the oxidation air and the slurry, reduce turbulent bubbles caused by oxidation air bubbles, and extend the residence time of the oxidation air, thereby improving the utilization rate of the oxidation air and achieving energy saving and consumption reduction. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a front view of the overall structure of Embodiment 1 of the present invention; Figure 2 This is a schematic cross-sectional view of the oxidation air main pipe in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the three-dimensional structure of the oxidation air main pipe in Embodiment 1 of the present invention; Figure 4 This is a top view of Embodiment 1 of the present invention, omitting the segment refiner and the support beam; Figure 5 This is a top view of the segment refiner and support beam in Embodiment 1 of the present invention.

[0019] Explanation of reference numerals in the attached figures: 1-Connecting pipe, 2-First valve, 4-Second valve, 5-Flushing water pipe, 6-Absorption tower, 7-Divider and refiner, 8-Support beam, 9-Support bracket, 10-Oxidation air main pipe, 11-Oxidation air branch pipe, 12-Air outlet. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] Example 1 like Figures 1-5 As shown, a limestone wet desulfurization oxidation air pipeline system includes an oxidation fan and several oxidation air headers 10. The several oxidation air headers 10 are connected in parallel and then connected to the oxidation fan through a connecting pipe 1. The oxidation fan is a commonly used device in this field and is omitted in the attached drawings. Its structure will not be described in detail here.

[0024] Connecting pipe 1 connects to flushing water pipe 5, and flushing water pipe 5 is connected to an external water pump. The water pump can be a process water pump, a demister flushing water pump, or a fire pump, to provide high-pressure flushing water to the flushing water pipe 5. The high-pressure flushing water flushes the oxidation air main pipe 10 and oxidation air branch pipe 11, achieving descaling and preventive maintenance without interrupting the desulfurization process, improving system operation continuity, reducing economic losses caused by downtime for descaling, extending pipe service life, and reducing maintenance costs.

[0025] A first valve 2 is installed on the connecting pipe 1, located between the oxidation blower and the oxidation blower main pipe 10. This valve facilitates quick disconnection of the flow between the oxidation blower and the main pipe 10 during flushing, preventing flushing water from entering the oxidation blower and damaging it. A flushing water pipe 5 is located between the first valve 2 and the oxidation blower main pipe 10, with a second valve 4 at the end of the flushing water pipe 5 closest to the connecting pipe 1. When the oxidation blower is operating, the second valve 4 is closed to prevent oxidation air from backflowing into the flushing water pipe 5. By installing the first valve 2 and the second valve 4, effective isolation between the flushing process and the operation of the oxidation blower is achieved, preventing flushing water from damaging the oxidation blower and preventing oxidation air from backflowing into the flushing water pipe 5.

[0026] The oxidation air header 10 passes through the wall of the absorption tower 6 and is located inside the absorption tower 6. The oxidation air header 10 is inclined downwards to facilitate the ejection of the slurry under the action of the oxidation air. Preferably, the middle of the oxidation air header 10 is concave to form the lowest point, and both ends of the oxidation air header 10 are inclined upwards. Preferably, the angle between the two ends of the oxidation air header 10 and the horizontal plane is 10-15°.

[0027] A plurality of oxidation air branch pipes 11 are evenly distributed on the oxidation air main pipe 10. The nozzle ends of the oxidation air branch pipes 11 away from the oxidation air main pipe 10 are inclined downwards, and the angle between the oxidation air branch pipes 11 and the horizontal plane is 15-25°. The connection between the oxidation air branch pipes 11 and the oxidation air main pipe 10 is smooth to avoid the formation of a "weir"-like structure between the inner walls of the oxidation air branch pipes 11 and the oxidation air main pipe 10, which would obstruct the fluid and cause eddy currents and liquid accumulation. Preferably, the bottom of the oxidation air branch pipes 11 is flush with the bottom of the oxidation air main pipe 10.

[0028] Both the main oxidation air pipe 10 and the branch oxidation air pipe 11 have several air outlets 12 on their lower side walls. The air outlets 12 are located at the bottom to effectively prevent slurry from flowing in from above. When the slurry enters the pipe through the air outlets 12, it can reduce the residence time of the slurry in the oxidation air pipe under the action of gravity and the thrust of the oxidation air, so as to quickly discharge it from the oxidation air pipe.

[0029] The nozzle end of the oxidation air branch pipe 11 has a conical conical nozzle structure, which facilitates the rapid discharge of small amounts of slurry entering the pipe and avoids slurry deposition and scaling. The air outlets 12 are all circular, and the diameter of the air outlets 12 on the oxidation air branch pipe 11 gradually increases along the airflow direction to compensate for the pressure loss of the oxidation air during the transportation process; based on the pressure drop efficiency of the oxidation air flowing to the end, the larger diameter of the air outlet 12 on the side closer to the nozzle end can promote more uniform diffusion of the oxidation air.

[0030] The oxidation air branch pipes 11 on adjacent oxidation air main pipes 10 are staggered. This ensures that the oxidation air branch pipes 11 are evenly distributed within the absorption tower 6, avoids mutual interference between the air outlets of adjacent oxidation air branch pipes 11, and allows the oxidation air to be evenly diffused throughout the entire slurry area within the absorption tower 6.

[0031] The absorption tower 6 is equipped with several support beams 8, each corresponding to an oxidation air main pipe 10. The support beams 8 and oxidation air main pipe 10 are fixedly connected by brackets 9. The support beams 8 provide support for the oxidation air main pipe 10 and the separator / refiner 7. Both ends of the support beams 8 are fixedly connected to the inner wall of the absorption tower 6. Preferably, both ends of the support beams 8 are fixedly connected to the inner wall of the absorption tower 6 by expansion bolts, and reinforcing plates are installed at the connection points to enhance the connection strength.

[0032] The top of the support beam 8 is equipped with a segmentation refiner 7, which has a mesh structure. The segmentation refiner 7 includes several transverse and longitudinal plates, which are arranged perpendicularly to each other to form a mesh structure. Preferably, both the transverse and longitudinal plates are made of stainless steel to avoid a decrease in the airflow refinement effect of the segmentation refiner 7 due to corrosion damage.

[0033] The segmentation refiner 7 is a modular structure, composed of several segmentation refinement components, covering the entire cross-section of the absorption tower 6 to ensure comprehensive segmentation. Each segmentation refinement component consists of transverse and longitudinal plates, which are welded together after perpendicular intersection, providing good stability. Each segmentation refinement component is fixedly connected to the support beam 8, preferably using bolt connections.

[0034] The oxidizing air ejected from the outlet holes 12 on the main oxidizing air pipe 10 and the branch oxidizing air pipe 11 forms bubbles in the slurry. After rising, the bubbles pass through the separator 7, where large bubbles are broken down into smaller bubbles, resulting in a longer residence time, a larger contact area, and a more uniform distribution of the oxidizing air bubbles. This allows the oxidizing air more time for the dissolution reaction, reducing the oxidizing air volume while maintaining the oxidation effect, thus achieving energy saving and consumption reduction. Simultaneously, the smaller bubbles reduce airflow disturbance, thereby reducing foaming of the slurry within the absorption tower 6 and improving oxidation efficiency.

[0035] This invention eliminates or reduces the failure rate by adopting the above-mentioned structure, thereby lowering the economic and time costs of manual maintenance and eliminating the safety risks associated with manual cleaning. Secondly, it improves the safety and reliability of the equipment, extends the stable operating time, and ensures safe and environmentally friendly production. Thirdly, through its design, it allows for precise adjustments to reduce equipment operating power, achieving energy conservation, consumption reduction, and improved economic efficiency.

[0036] Work process: Close the second valve 4 and open the first valve 2. The oxidation blower starts to run. The oxidation air output by the oxidation blower is delivered to each oxidation air main pipe 10 through the connecting pipe 1. After being split by the oxidation air main pipe 10, it enters the oxidation air branch pipe 11. The oxidation air is evenly sprayed out from the air outlet 12 at the bottom of the oxidation air main pipe 10 and the oxidation air branch pipe 11, and acts on the slurry in the absorption tower 6. The branch pipes on the adjacent main pipes are staggered to make the oxidation air evenly diffused to the entire slurry area, ensuring that the oxidation reaction is sufficient.

[0037] The oxidizing air ejected from the air outlets 12 on the main oxidizing air pipe 10 and the branch oxidizing air pipe 11 forms bubbles in the slurry. After the bubbles rise, they pass through the divider 7, where large bubbles are broken down into smaller bubbles. This results in longer residence time, larger contact area, and more uniform distribution of the oxidizing air bubbles, leading to a more complete oxidation reaction.

[0038] When the oxidation blower is shut down, preventive maintenance is performed on the pipeline. First valve 2 is closed, second valve 4 is opened, and water pump is turned on. High-pressure flushing water is used to flush the oxidation blower main pipe 10 and oxidation blower branch pipe 11. After descaling is completed, water pump and second valve 4 are closed, and first valve 2 is opened. The oxidation blower then runs normally.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A limestone wet desulfurization oxidation air duct system, characterized in that, The device includes an oxidation blower and several oxidation blower main pipes. The oxidation blower is connected to the oxidation blower via a connecting pipe after the several oxidation blower main pipes are connected in parallel. The oxidation blower main pipes pass through the wall of the absorption tower and are located inside the absorption tower. The oxidation blower main pipes are inclined downwards. Several oxidation blower branch pipes are evenly distributed on the oxidation blower main pipes. The nozzle ends of the oxidation blower branch pipes away from the oxidation blower main pipes are inclined downwards. Several air outlet holes are provided on the lower side walls of the oxidation blower main pipes and the oxidation blower branch pipes.

2. The limestone wet desulfurization oxidation air duct system according to claim 1, characterized in that, The nozzle end of the oxidation air branch pipe has a conical nozzle structure.

3. The limestone wet desulfurization oxidation air duct system according to claim 1, characterized in that, The diameter of the air outlet on the oxidation air branch pipe gradually increases along the airflow direction.

4. The limestone wet desulfurization oxidation air duct system according to claim 1, characterized in that, The angle between the main oxidation air pipe and the horizontal plane is 10-15°, and the angle between the branch oxidation air pipe and the horizontal plane is 15-25°.

5. The limestone wet desulfurization oxidation air duct system according to claim 1, characterized in that, The oxidation air branch pipes on adjacent oxidation air main pipes are arranged in an alternating manner.

6. The limestone wet desulfurization oxidation air duct system according to claim 1, characterized in that, The absorption tower is equipped with several support beams, which are fixedly connected to the oxidation air main pipe by brackets.

7. The limestone wet desulfurization oxidation air duct system according to claim 6, characterized in that, The top of the support beam is equipped with a segmentation refiner, which has a mesh structure.

8. The limestone wet desulfurization oxidation air duct system according to claim 7, characterized in that, The segmentation refiner includes several horizontal and vertical slices, which are arranged perpendicularly to each other to form a mesh structure.

9. The limestone wet desulfurization oxidation air duct system according to claim 1, characterized in that, The connecting pipe is connected to the flushing water pipe, and the flushing water pipe is connected to an external water pump.

10. The limestone wet desulfurization oxidation air duct system according to claim 9, characterized in that, The connecting pipe is equipped with a first valve, the flushing water pipe is located between the first valve and the oxidation air main pipe, and the flushing water pipe is equipped with a second valve at one end near the connecting pipe.

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