Auxiliary desulfurization system for boiler return ash

Abstract

The utility model relates to an auxiliary desulfurization system for boiler return ash, which comprises a flue gas treatment system and a raw material calcining system, and the flue gas treatment system comprises a desulfurizing agent powder bin for storing and supplying a desulfurizing agent; the raw material calcining system comprises a calcining boiler for calcining raw materials; the return ash utilization channel is communicated with the raw material calcining system and a desulfurizing agent powder bin of the flue gas treatment system, and boiler return ash generated by the calcining boiler can be supplied to the desulfurizing agent powder bin by the return ash utilization channel. According to the boiler return ash auxiliary desulfurization system, the return ash utilization channel communicated with the raw material calcining system and the flue gas treatment system is arranged, so that the purpose that return ash in the calcining boiler is conveyed into the desulfurizing agent powder bin to be mixed with a desulfurizing agent for flue gas desulfurization is achieved. Due to the fact that the effect of the desulfurizing agent is replaced by a part of produced boiler return ash, the consumption of the purchased desulfurizing agent in the desulfurizing process is reduced, and the using cost of the desulfurizing agent is saved.

Description

Technical Field

[0001] This utility model relates to the field of dry desulfurization technology, specifically to a boiler ash return auxiliary desulfurization system. Background Technology

[0002] The cement industry requires the calcination treatment of raw materials, but the sulfur content within these upstream raw materials is currently difficult to control effectively. During the calcination process, sulfur enters the exhaust gas as sulfur dioxide, resulting in excessive sulfur content in the emissions without treatment. Even after the implementation of SCR (Selective Catalytic Reduction) technology and the shutdown of the raw material mill, the system's sulfur content remains severely excessive, fluctuating frequently to 350 mg / m³, failing to meet environmental protection requirements. Desulfurization using desulfurizing agents requires approximately 5 tons per shutdown. Current dry desulfurization technology involves injecting desulfurizing agent dust into the exhaust gas to convert sulfur dioxide into solid particles such as sulfates, capturing and adsorbing sulfur. The desulfurizing agents typically consist of sodium bicarbonate, making them expensive to purchase externally. Utility Model Content

[0003] Given that the dry desulfurization technology used in existing cement production processes uses purchased desulfurizing agents to capture and adsorb sulfur elements in flue gas, the consumption of these desulfurizing agents is large and the unit price is high, resulting in high cost pressure. This utility model provides a boiler ash return auxiliary desulfurization system.

[0004] The technical solution of this utility model provides a boiler ash return auxiliary desulfurization system, including...

[0005] The flue gas treatment system includes a desulfurizer powder silo for storing and supplying desulfurizing agents;

[0006] Raw material calcination system, which includes a calcination boiler for calcining raw materials;

[0007] The ash recovery channel connects the raw material calcination system and the desulfurizing agent powder silo of the flue gas treatment system. The ash recovery channel can supply boiler ash generated by the calcination boiler to the desulfurizing agent powder silo.

[0008] Preferably, the raw material calcination system

[0009] It includes an ash return bin for storing ash return and a conveying device for conveying boiler ash return between the ash return bin and the calcining boiler.

[0010] Preferably, the ash return is connected to the conveying device and the desulfurizing agent powder silo via a channel to distribute the boiler ash return from the conveying device to the desulfurizing agent powder silo.

[0011] Preferably, the vertical height of the conveying device is higher than that of the desulfurizing agent powder silo.

[0012] Preferably, the ash return channel is a closed-section tubular channel with one end open to the conveying device and the other end open to the desulfurizing agent powder silo.

[0013] Preferably, the conveying device is a zipper machine.

[0014] Preferably, a valve plate is provided in the ash recovery channel, and the valve plate controls the opening and closing of the ash recovery channel.

[0015] Preferably, the valve plate is disposed at the junction of the zipper machine and the ash return channel.

[0016] Preferably, a dividing wheel is installed below the opening of the ash return utilization channel extending to the desulfurizing agent powder silo. The blades of the dividing wheel periodically sweep across the area below the ash return utilization channel, thereby pushing and dispersing the falling boiler ash within the desulfurizing agent powder silo.

[0017] Preferably, a plurality of vibrating motors are distributed circumferentially at the lower part of the desulfurizing agent powder silo.

[0018] This utility model's boiler ash-assisted desulfurization system achieves the goal of transporting ash from the calcining boiler to the desulfurizing agent powder silo and mixing it with the desulfurizing agent for flue gas desulfurization by setting up an ash utilization channel connecting the raw material calcining system and the flue gas treatment system. Since a portion of the boiler ash produced replaces the function of the desulfurizing agent, this reduces the consumption of externally purchased desulfurizing agent during the desulfurization process. Actual measurements show that after the improvement, using calcining boiler ash to replace part of the desulfurizing agent can reduce the SO2 emission concentration of kiln tail flue gas by 20%-40% compared to using ash alone for desulfurization. The mixed use of ash and desulfurizing agent can effectively reduce the SO2 emission concentration by 40%-80%, saving on desulfurizing agent costs while achieving the desired desulfurization effect. Attached Figure Description

[0019] Figure 1 This is a schematic diagram illustrating the principle of existing dry desulfurization technology.

[0020] Figure 2 This is a schematic diagram of the boiler ash return auxiliary desulfurization system of this utility model;

[0021] Figure 3 This is a schematic diagram of one embodiment of the boiler ash return auxiliary desulfurization system of this utility model;

[0022] Figure 4 This is a schematic diagram showing the connection between the ash recovery channel 6 and the conveying device 7 of this utility model;

[0023] Figure 5 This is a schematic diagram showing the connection of the ash return utilization channel 6 in the desulfurizing agent powder silo 2 of this utility model.

[0024] In the picture:

[0025] 1: Calcination boiler; 10: Valve plate; 11: Dividing wheel; 12: Zipper machine; 13: Vibrating motor; 2: Desulfurizing agent powder silo; 3: Desulfurization reactor; 4: Dust collector; 5: Fan; 6: Ash recovery channel; 7: Conveying device; 8: Ash recovery silo; 9: Chute. Detailed Implementation

[0026] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. In this specification, the dimensions of the drawings do not represent the actual dimensions. They are only used to illustrate the relative positional and connection relationships between the components. Components with the same name or the same reference numeral represent similar or identical structures and are limited to illustrative purposes.

[0027] Existing dry desulfurization technologies such as Figure 1 As shown, the desulfurizing agent is stored in the desulfurizing agent powder silo 2 and is sent to the desulfurization reactor 3 of the flue gas treatment system by the fan 5 through the channel. After the sulfur-containing flue gas and the desulfurizing agent powder are fully mixed, the sulfur element is converted and adsorbed into the solid dust. After passing through the desulfurization reactor 3, the flue gas and dust are sent to the dust collector 4. The dust is collected in the dust collector 4, and the flue gas continues to be discharged from the dust collector 4, thus removing the sulfur element from the flue gas.

[0028] In cement production, various calcination and other combustion-heating processes generate sulfur-containing flue gas. Sulfur elements in the raw materials also produce sulfur dioxide gas during calcination, which enters the flue gas, easily leading to excessive sulfur content. Existing technologies remove this sulfur through the aforementioned dry desulfurization technology. Furthermore, after treatment in the calcination boiler 1, recycled ash is obtained as part of the calcination products and needs to be collected and stored in a silo for future use. The recycled ash contains components such as calcium oxide after calcination and can also be used for desulfurization treatment.

[0029] Figure 2 This is a schematic diagram of the boiler ash-assisted desulfurization system of this utility model. The system includes a flue gas treatment system and a raw material calcination system. The flue gas treatment system includes a desulfurizing agent powder silo 2 for storing and supplying desulfurizing agents, and the raw material calcination system includes a calcination boiler 1 for calcining raw materials. To utilize the ash generated during the calcination process, the system has an ash utilization channel 6 located between the raw material calcination system and the flue gas treatment system. Through the ash utilization channel 6, some or all of the boiler ash generated in the calcination boiler 1 can be supplied to the desulfurizing agent powder silo 2. The boiler ash can be mixed with the desulfurizing agent to achieve flue gas desulfurization with a smaller amount of desulfurizing agent.

[0030] Figure 3This is one embodiment of the boiler ash return-assisted desulfurization system of this utility model. The raw material calcination system also includes an ash return bin 8 for storing ash. A conveying device 7 is located between the calcination boiler 1 and the ash return bin 8 to transport the ash generated in the calcination boiler 1 to the ash return bin 8 for storage. In fact, the calcination boiler 1 integrates a fan. Under the action of the fan, the powdery ash obtained from calcination is blown out and collected, and the ash is fed onto the conveying device 7 in the calcination boiler 1. The conveying device 7 can generally be of various forms; in this embodiment, the conveying device 7 is preferably a zipper conveyor. The ash return is distributed to the desulfurizing agent powder bin 2 by connecting the conveying device 7 and the desulfurizing agent powder bin 2 via a channel 6. In the specific equipment architecture, there is a vertical height difference between the conveying device 7 and the desulfurizing agent powder bin 2. Directly setting the ash return to connect the conveying device 7 and the desulfurizing agent powder bin 2 via a channel can preferably eliminate the need for an additional power unit, allowing the boiler ash to be distributed to the desulfurizing agent powder bin 2 by gravity. The ash recovery channel 6 is preferably a tubular channel with a closed cross section to prevent the ash from spreading into the external space and causing dust pollution. One implementation of the ash recovery channel 6 that meets this feature is a pipe-shaped chute with open ends, which is made of multiple steel plates spliced ​​and welded together. One end of the chute is connected to the conveying device 7, and the other end extends into the desulfurizing agent powder silo 2.

[0031] like Figure 4 As shown, when the conveying device 7 is a zipper conveyor 12, a movable valve plate 10 is preferably installed at the junction of the zipper conveyor 12 and the ash return utilization channel 6. The valve plate 10 is used to control the opening and closing of the ash return utilization channel 6. First, an opening is made at the bottom of the zipper conveyor 12, and the ash return utilization channel 6, such as a chute, is connected to the opening to realize the distribution of boiler ash return to the desulfurizing agent powder silo 2. The valve plate 10 is preferably located at the bottom opening of the zipper conveyor 12, and the opening can be closed or opened with a variable opening degree. When the opening is closed, the zipper conveyor 12 only performs the normal task of conveying boiler ash return to the ash return silo 8. At this time, since the valve plate 10 is placed at its bottom opening and closed, there is no problem of ash return remaining in the ash return utilization channel 6 or the zipper conveyor 12.

[0032] like Figure 5 As shown, preferably, a dividing wheel 11 is also provided below the opening of the ash return utilization channel 6 extending to the desulfurizing agent powder silo 2. The dividing wheel 11 has several blades arranged around its vertical axis. During operation, the dividing wheel 11 rotates around its vertical axis, and the blades periodically sweep across the area below the ash return utilization channel 6, thereby pushing and dispersing the falling ash within the desulfurizing agent powder silo 2, achieving the purpose of ash mixing. Simultaneously, the periodic sweeping of the dividing wheel 11 also prevents material blockage and unstable material feeding at the outlet of the ash return utilization channel 6.

[0033] Several vibrating motors 13 can be distributed around the bottom of the desulfurizing agent powder silo 2 to make the shell of the desulfurizing agent powder silo 2 vibrate, which is conducive to the falling of powder in the desulfurizing agent powder silo 2, reduces powder adhesion to the wall, and helps the desulfurizing agent and boiler ash to mix evenly in the desulfurizing agent powder silo 2.

[0034] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of the present utility model. Any modifications and improvements made to the technical solution of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A boiler ash recycling auxiliary desulfurization system, characterized in that, Comprising A flue gas treatment system, the flue gas treatment system comprising a desulfurizer powder bin (2) for storing and supplying desulfurizer; A raw material calcination system, the raw material calcination system comprising a calcination boiler (1) for calcination of raw material; A fly ash utilization passage (6) connecting the raw material calcination system and the desulfurizer powder bin (2) of the flue gas treatment system, the fly ash utilization passage (6) being capable of supplying boiler fly ash generated by the calcination boiler (1) into the desulfurizer powder bin (2).

2. The boiler ash sludging auxiliary desulfurization system as claimed in claim 1, wherein, The raw material calcination system comprises a fly ash bin (8) for storing fly ash and a conveying device (7) for conveying boiler fly ash between the fly ash bin (8) and the calcination boiler (1).

3. The boiler ash sludging auxiliary desulfurization system as claimed in claim 2, wherein, The fly ash utilization passage (6) is connected to the conveying device (7) and inside the desulfurizer powder bin (2) to deliver the boiler fly ash in the conveying device (7) into the desulfurizer powder bin (2).

4. The boiler ash sludging auxiliary desulfurization system as claimed in claim 3, wherein, The conveying device (7) has a height in vertical direction higher than the desulfurizer powder bin (2).

5. The boiler fly ash assisted desulfurization system as claimed in claim 2, wherein, The fly ash utilization passage (6) is a tubular passage with a closed cross section, one end of which is open to connect to the conveying device (7) and the other end of which is open to extend into the desulfurizer powder bin (2).

6. The boiler fly ash assisted desulfurization system of any one of claims 2-5, wherein, The conveying device (7) is a draw machine.

7. The boiler fly ash assisted desulfurization system of claim 6, wherein, A valve plate (10) is arranged in the fly ash utilization passage (6) to control opening and closing of the fly ash utilization passage (6).

8. The boiler ash sludging auxiliary desulfurization system as claimed in claim 7, wherein The valve plate (10) is arranged at the joint of the draw machine (12) and the fly ash utilization passage (6).

9. The boiler fly ash assisted desulfurization system of any one of claims 1-5, wherein, A dividing wheel (11) is arranged below the opening of the fly ash utilization passage (6) extending into the desulfurizer powder bin (2), blades of the dividing wheel (11) periodically sweep below the fly ash utilization passage (6) to push and disperse the falling boiler fly ash in the desulfurizer powder bin (2).

10. The boiler fly ash assisted desulfurization system of any one of claims 1-5, wherein, A plurality of vibrating motors (13) are distributed along the circumference of the lower part of the desulfurizer powder bin (2).

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