Flue dust removal system for vertical flue of ferrosilicon waste heat boiler

Abstract

The application discloses a vertical flue dust removal system of a ferrosilicon waste heat boiler, and solves the problem of how to effectively remove dust from the tail vertical flue of a ferrosilicon waste heat circulating fluidized bed boiler; a bucket elevator (4) is arranged at the rear outer side of the vertical flue (1), a bucket elevator bottom bin (7) is connected to the bottom end of the bucket elevator (4), a steel ball collecting conical bin (5) is arranged at the inner bottom end of the vertical flue (1), a lower screw conveyor (6) is arranged between the steel ball collecting conical bin (5) and the bucket elevator bottom bin (7), a steel ball storage tank (9) is arranged at the top end in the vertical flue (1), a steel ball scattering distribution bin (11) is arranged at the lower portion of the steel ball storage tank (9), a steel ball scattering pipeline (12) is connected to the bottom end, and the lower end of the steel ball scattering pipeline (12) is arranged directly above economizer tube rows (2); and the dust is circularly scattered and removed.

Description

Technical Field

[0001] This invention relates to a ferrosilicon waste heat boiler, and more particularly to a vertical flue cleaning system for a ferrosilicon waste heat boiler. Background Technology

[0002] In the vertical flue at the tail end of the ferrosilicon waste heat boiler, superheater tube banks and economizer tube banks are arranged. The flue gas in the boiler furnace is discharged after passing through the superheater tube banks and economizer tube banks in the flue. During the operation of the ferrosilicon waste heat boiler, due to the high dust content in the flue gas, the fly ash in the flue gas easily adheres to the various heating surfaces of the vertical flue when the boiler flue gas is discharged through the vertical flue, reducing the heat exchange efficiency of the heating surfaces of the tube banks in the flue and affecting the adjustment of the boiler load. Therefore, it is necessary to remove ash from the heating surfaces of the flue. The existing ash removal methods are mainly wire brush cleaning and steam blowing. However, wire brush cleaning is suitable for vertical heating surfaces but not for horizontal heating surfaces, while steam cleaning has poor cleaning effect. How to design a simple and practical ash removal system for the vertical flue at the tail end of the ferrosilicon waste heat boiler has become an urgent problem to be solved on site. Summary of the Invention

[0003] This invention provides a vertical flue cleaning system for ferrosilicon waste heat boilers, solving the technical problem of how to effectively clean the tail vertical flue of ferrosilicon waste heat circulating fluidized bed boilers.

[0004] The present invention solves the above technical problems through the following technical solutions:

[0005] A vertical flue cleaning system for a ferrosilicon waste heat boiler includes a vertical flue. Superheater tube banks and economizer tube banks are arranged at intervals along a downward direction within the vertical flue. An induced draft fan is installed at the tail outlet of the vertical flue. A bucket elevator is installed on the outer rear side of the vertical flue. A bucket elevator bottom hopper is connected to the bottom of the bucket elevator. A steel ball collecting cone hopper is installed at the bottom of the vertical flue. A lower screw conveyor is installed between the steel ball collecting cone hopper and the bucket elevator bottom hopper. The system also includes a system at the top of the vertical flue. A steel ball storage tank is provided, with an upper screw conveyor between the top inlet of the steel ball storage tank and the top of the bucket elevator. A steel ball dispersing and distribution chamber is located at the bottom of the steel ball storage tank. A gate valve is installed inside the steel ball storage tank at the top of the steel ball dispersing and distribution chamber. A steel ball dispersing pipe is connected to the bottom of the steel ball dispersing and distribution chamber. The lower end of the steel ball dispersing pipe is located directly above the superheater tube bank. A lifting ring is connected to the lower end of the steel ball dispersing pipe, and steel ball impact dispersion balls are suspended on the lifting ring. Steel balls are stored in the steel ball storage tank.

[0006] The steel balls are 8 mm in diameter, and the steel ball dispersing pipes are 108 mm in diameter. Two rows of steel ball dispersing pipes are arranged in an array at the bottom of the steel ball dispersing and distribution chamber. The steel balls on the hanging rings connected to the lower ends of each steel ball dispersing pipe impact the steel ball dispersing spheres, and the total area of ​​the steel ball dispersing area covers the inner cross-section of the vertical flue.

[0007] A new steel ball replenishment bin is connected to the bottom hopper of the bucket elevator; a smoke and ash filter screen is installed inside the bottom hopper of the bucket elevator; and the bottom surface of the outer shell of the lower screw conveyor is a grating that allows ash to pass through.

[0008] A method for cleaning the ash removal system of a vertical flue of a ferrosilicon waste heat circulating fluidized bed boiler, characterized by the following steps:

[0009] Step 1: When fly ash adheres to the superheater tube bank and economizer tube bank, open the gate valve. The steel balls stored in the steel ball storage tank fall into the steel ball distribution chamber and are distributed into each steel ball distribution pipe.

[0010] The second step is that the steel balls entering the steel ball dispersing pipe fall along the vertical section of the steel ball dispersing pipe, and after leaving the lower end of the steel ball dispersing pipe, they fall onto the steel ball impact dispersion ball and spread out in a fan shape.

[0011] The third step involves the fan-shaped steel balls continuing to fall, landing on the topmost superheater tube bank and impacting the fly ash adhering to it. The fly ash that is knocked off falls through the gaps in the superheater tube bank and is then sucked out of the vertical flue by the induced draft fan. At the same time, the steel balls that have impacted the fly ash fall through the gaps in the superheater tube bank and then impact the fly ash adhering to the tube bank below before continuing to fall.

[0012] Step 4: After the steel balls fall to the bottom of the vertical flue, they enter the conical bin for collecting steel balls. Then, they are conveyed by the lower screw conveyor into the hopper at the bottom of the bucket elevator.

[0013] Step 5: The steel balls in the bottom hopper of the bucket elevator are lifted to the top of the bucket elevator, and then enter the upper screw conveyor and are transported into the steel ball storage tank.

[0014] When the steel balls are conveyed into the bottom hopper of the bucket elevator by the lower screw conveyor, the fly ash in the lower screw conveyor enters along with the steel balls. During the screw conveying process, the fly ash falls through the ash-leaking grid on the bottom surface of the outer shell of the lower screw conveyor, thus separating the steel balls from the fly ash.

[0015] The steel ball ash removal device of the present invention is an auxiliary device for waste heat boilers, used for cleaning vertical flue gas. Steel balls with a diameter of 8 mm are freely dispersed from the top of the flue through a dispersing pipe, filling the entire cross-section of the flue. As the steel balls fall freely, they continuously impact the heating surfaces within the flue, removing accumulated ash. A conical collection chamber is provided at the bottom of the flue, where most of the accumulated ash is drawn into a dust collector by airflow, while a small portion is effectively separated by a spiral separator. The cleaned steel balls are then transported to the top of the flue via a hoist for cyclical dispersing and ash removal. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention;

[0017] Figure 2 yes Figure 1 Sectional view along line AA in the middle;

[0018] Figure 3 yes Figure 2 BB-direction sectional view in the middle;

[0019] Figure 4 This is a schematic diagram of the steel ball lifting and dispersing structure of the present invention. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings:

[0021] A vertical flue gas ash removal system for a ferrosilicon waste heat boiler includes a vertical flue 1. In the vertical flue 1, superheater tube banks 2 and economizer tube banks 3 are arranged at intervals from top to bottom. Each tube bank is arranged horizontally, with a gap of approximately 40-50 mm in each bank. An induced draft fan is installed at the outlet of the vertical flue 1 to draw the flue gas outwards. A bucket elevator 4 is installed on the outer rear side of the vertical flue 1, its function being to lift ash removal steel balls to the top of the flue. A bucket elevator bottom hopper 7 is connected to the bottom end of the bucket elevator 4. Steel balls are stored in the bottom hopper 7 of the bucket elevator. A conical hopper 5 for collecting steel balls is located at the bottom of the vertical flue 1. Steel balls falling from above the vertical flue 1 are collected by the conical hopper 5. A lower screw conveyor 6 is located between the conical hopper 5 and the bottom hopper 7 of the bucket elevator. A steel ball storage tank 9 is located at the top of the vertical flue 1. An upper screw conveyor 8 is located between the top inlet of the steel ball storage tank 9 and the top of the bucket elevator 4. A steel ball distribution bin 11 is located below the steel ball storage tank 9. A steel ball distribution bin 11 is located at the top of the steel ball distribution bin 11. A gate valve 10 is installed inside the steel ball storage tank 9. The gate valve 10 controls the steel balls in the steel ball storage tank 9 to enter the steel ball distribution chamber 11. A steel ball distribution pipe 12 is connected to the bottom of the steel ball distribution chamber 11. The steel balls in the distribution chamber 11 are distributed and fall into the upper port of the steel ball distribution pipe 12. A row of distribution pipes is arranged at intervals in the vertical flue 1. The lower part of each steel ball distribution pipe 12 is a vertical pipe, allowing the steel balls to fall freely. The lower port of the steel ball distribution pipe 12 is located directly above the superheater tube bank 2. A lifting ring 13 is connected to the upper part of the steel ball dispersing pipe 12, and a steel ball impact dispersing ball 14 is suspended on the lifting ring 13. The steel ball impact dispersing ball 14 is located directly below the lower end of the steel ball dispersing pipe 12. The steel balls falling from the steel ball dispersing pipe 12 are throttled by the steel ball impact dispersing ball 14, so that the falling trajectory of the steel balls is dispersed in an umbrella shape before falling onto the pipe bank, thereby achieving an impact on a certain area of ​​the pipe bank. The area of ​​steel balls dispersed by each steel ball dispersing pipe 12 covers the pipe bank, thereby achieving a large-area impact on the pipe bank in the flue and knocking off the fly ash adhering to it. The steel balls are stored in the steel ball storage tank 9.

[0022] The steel ball has a diameter of 8 mm, and the steel ball dispersing pipe 12 has a diameter of 108 mm. Two rows of steel ball dispersing pipes 12 are arranged in an array at the bottom of the steel ball dispersing and distribution chamber 11. The steel balls on the hanging rings 13 connected to the lower end of each steel ball dispersing pipe 12 impact the steel ball dispersing sphere 14, and the sum of the steel ball dispersing area covers the inner cavity cross section of the vertical flue 1.

[0023] A new steel ball replenishment bin 15 is connected to the bottom hopper 7 of the bucket elevator. During initial use, steel balls can be transported to the steel ball storage tank 9 through the new steel ball replenishment bin 15. If new steel balls need to be replenished during ash removal, they can also be replenished through the new steel ball replenishment bin 15. A fly ash filter screen is installed inside the bottom hopper 7 of the bucket elevator. The bottom surface of the outer shell of the lower screw conveyor 6 is a ash-permeable grid. Since the steel balls entering the steel ball collecting cone hopper 5 carry some fly ash, when the steel balls carrying fly ash are conveyed by the lower screw conveyor 6, the fly ash can be separated through the ash-permeable grid on the bottom surface of the outer shell. A filter screen is also installed at the inlet of the bottom hopper 7 of the bucket elevator to achieve secondary separation of steel balls and fly ash, ensuring that cleaner steel balls are lifted and reused for ash removal.

[0024] A method for cleaning the vertical flue of a ferrosilicon waste heat boiler, used for cleaning ferrosilicon waste heat boilers, involves freely distributing 8 mm diameter steel balls from the top of the flue through a dispersing pipe, filling the entire cross-section of the flue. As the steel balls fall freely, they continuously impact the heating surfaces within the flue, thus removing accumulated ash. The method is characterized by the following steps:

[0025] Step 1: When fly ash adheres to the superheater tube bank 2 and economizer tube bank 3, open the gate valve 10. The steel balls stored in the steel ball storage tank 9 fall into the steel ball distribution chamber 11 and are distributed into each steel ball distribution pipe 12.

[0026] The second step is that the steel balls entering the steel ball dispersing pipe 12 fall along the vertical section of the steel ball dispersing pipe, and after leaving the lower end of the steel ball dispersing pipe 12, they fall onto the steel ball impact dispersion ball 14 and spread out in a fan shape.

[0027] The third step involves the fan-shaped steel balls continuing to fall, landing on the topmost superheater tube bank 2, where they impact the fly ash adhering to the tube bank. The fly ash that is knocked off falls through the gaps in the superheater tube bank 2 and is then sucked out of the vertical flue by the induced draft fan. At the same time, the steel balls that have impacted the fly ash fall through the gaps in the superheater tube bank 2 and then impact the fly ash adhering to the tube bank below before continuing to fall.

[0028] Step 4: After the steel balls fall to the bottom of the vertical flue 1, they enter the steel ball collection cone 5, and then are conveyed by the lower screw conveyor 6 into the bottom hopper 7 of the bucket elevator.

[0029] Step 5: The steel balls in the bottom hopper 7 of the bucket elevator are lifted to the top of the bucket elevator 4, and then enter the upper screw conveyor 8 and are transported into the steel ball storage tank 9.

[0030] Ash removal is carried out intermittently, and the interval can be determined based on the amount of fly ash contaminating the pipes.

[0031] When the steel balls are conveyed by the lower screw conveyor 6 into the bottom hopper 7 of the bucket elevator, the fly ash in the lower screw conveyor 6 along with the steel balls falls through the ash-leaking grid on the bottom surface of the outer shell of the lower screw conveyor 6 during the screw conveying process, thus separating the steel balls from the fly ash.

Claims

1. A flue dust removal system for a ferrosilicon waste heat boiler vertical flue, comprising a vertical flue (1), in which, along the direction from top to bottom, superheater tube rows (2) and economizer tube rows (3) are arranged at intervals, and an induced draft fan is arranged at the tail outlet of the vertical flue (1); characterized in that, A bucket elevator (4) is installed on the outer side of the rear of the vertical flue (1). A bucket elevator bottom hopper (7) is connected to the bottom of the bucket elevator (4). A steel ball collecting cone hopper (5) is installed at the bottom of the vertical flue (1). A lower screw conveyor (6) is installed between the steel ball collecting cone hopper (5) and the bucket elevator bottom hopper (7). A steel ball storage tank (9) is installed at the top of the vertical flue (1). An upper screw conveyor (8) is installed between the top inlet of the steel ball storage tank (9) and the top of the bucket elevator (4). A steel ball distribution chamber (11) is provided at the bottom of the steel ball storage tank (9). A gate valve (10) is provided inside the steel ball storage tank (9) at the top of the steel ball distribution chamber (11). A steel ball distribution pipe (12) is connected to the bottom of the steel ball distribution chamber (11). The lower end of the steel ball distribution pipe (12) is located directly above the economizer pipe bank (3). A lifting ring (13) is connected to the lower end of the steel ball distribution pipe (12). A steel ball impact dispersion ball (14) is suspended on the lifting ring (13). Steel balls are stored in the steel ball storage tank (9).

2. The dust removal system for the vertical flue of a ferrosilicon waste heat boiler according to claim 1, characterized in that, The diameter of the steel ball is 8 mm, and the diameter of the steel ball dispersing pipe (12) is 108 mm. Two rows of steel ball dispersing pipes (12) are arranged in an array at the bottom of the steel ball dispersing and distribution chamber (11). The steel balls on the hanging ring (13) connected to the lower end of each steel ball dispersing pipe (12) impact the steel ball dispersing sphere (14) and cover the inner cross-section of the vertical flue (1).

3. The dust removal system for the vertical flue of a ferrosilicon waste heat boiler according to claim 1 or 2, characterized in that, A new steel ball replenishment bin (15) is connected to the bottom hopper (7) of the bucket elevator; a smoke and ash filter screen is installed inside the bottom hopper (7) of the bucket elevator; and a ash-leaking fence is installed on the bottom surface of the outer shell of the lower screw conveyor (6).

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