Ash dredging system for accumulated ash at flue inlet section of fluidized bed separator

Abstract

The invention discloses an ash dredging system for accumulated ash at a flue inlet section of a fluidized bed separator, and relates to the technical field of fluidized beds. The invention aims to solve the problems of low safety and reliability in the operation of the separator caused by the ash deposition phenomenon at the flue inlet section of the existing fluidized bed separator. The pressure of the horizontal section of the inlet flue of the fluidized bed separator is-100 Pa under the low-load working condition, the pressure of the conical section of the separator is-1000 Pa, the different pressure difference between the horizontal section of the inlet flue and the conical section of the separator serves as power, an ash hopper and an ash falling pipe are arranged between the horizontal section of the inlet flue and the conical section of the separator, and the purpose of ash conveying of the inlet section is achieved; a gravity flap valve is arranged on the lower portion of the ash hopper and can be opened and closed according to the weight of accumulated ash in the ash hopper, the ash in the ash hopper is discharged into the conical section of the separator through the ash falling pipe, the front ash hopper and the rear ash hopper are arranged front and back and can operate independently, and a compressed air purging pipe is arranged at the turning position of the ash falling pipe to prevent the ash from being accumulated in the ash falling pipe. The invention is suitable for the technical field of fluidized bed separators.

Description

Technical Field

[0001] The invention relates to the technical field of fluidized beds, and in particular to an ash removal system for ash accumulation at an inlet section of a flue of a fluidized bed separator. Background Art

[0002] In recent years, with the continuous improvement of the peak-shaving operation capacity of fluidized bed boilers in large power plants, the deep peak-shaving has reached a load capacity of 20%-25%, and the load-shaving operation range of fluidized bed boilers has become larger. In this wide load operation range, the flue gas duct at the inlet of the separator is designed to be a horizontal section or a downward angle of 15°, with a length of about 4 to 5m. Under low-load conditions, the flue gas velocity is less than 8m / s, and it is easy to accumulate ash in the inlet section. After the ash accumulates in the flue gas, the flue gas flow resistance increases, the load of the induced draft fan increases, and the flow field distribution of the separator inlet is destroyed, which has an adverse effect on the separation efficiency. If a large amount of ash is not cleaned in time, it is easy to cause ash collapse, which can easily cause the separator to fail to operate normally. Summary of the invention

[0003] The present invention aims to solve the problem of dust accumulation at the flue inlet section of the existing fluidized bed separator, which leads to low safety and reliability in the operation of the separator, and proposes a dust removal system for dust accumulation at the flue inlet section of the fluidized bed separator.

[0004] The present invention discloses an ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator, which comprises a separator inlet section 1, a flue expansion joint 2, a separator inlet docking flange 3, a front ash hopper 4, a rear ash hopper 5, a gravity flap valve 6, a transition section 7, an expansion joint 8, a front ash falling pipe 9, a rear ash falling pipe 10, an ash falling pipe main pipe 12, a separator body tapered section 15, a separator body straight section 16 and a separator outlet section 17;

[0005] One end of the separator inlet section 1 is connected to one end of the separator inlet docking flange 3 through the flue expansion joint 2, and the other end of the separator inlet docking flange 3 is connected to the input end of the separator body straight section 16, the top output end of the separator body straight section 16 is connected to the separator outlet section 17, and the bottom output end of the separator body straight section 16 is connected to the top of the separator body conical section 15, and the outer surface bottom of the separator body conical section 15 is provided with a front ash hopper 4, and the outer surface bottom of the separator inlet section 1 is provided with a rear ash hopper 5, and the front ash hopper 4 and the rear ash hopper 5 are connected to the separator body conical section 15. The bottom output end of the hopper 5 is provided with a gravity flap valve 6, a transition section 7 and an expansion joint 8 in sequence along the height direction. The bottom end of the expansion joint 8 connected to the bottom of the front ash hopper 4 is connected to the top of the front ash falling pipe 9, the bottom end of the ash falling pipe 9 is connected to one end of the ash falling pipe main pipe 12, and the other end of the ash falling pipe main pipe 12 is connected to the outer surface input end of the separator body conical section 15. The circumferential outer surface of the front ash falling pipe 9 is processed with through holes, and the through holes on the outer surface of the front ash falling pipe 9 are connected to the bottom of the expansion joint 8 at the bottom connection of the rear ash hopper 5 through the rear ash falling pipe 10;

[0006] Furthermore, a compressed air pipe 11 is provided at the bottom connection of the expansion joint 8 at the bottom connection of the rear ash drop pipe 10 and the rear ash hopper 5;

[0007] Furthermore, a compressed air pipe 11 is provided at the connection between the bottom end of the ash falling pipe 9 and one end of the ash falling pipe main pipe 12;

[0008] Furthermore, an expansion joint 8 is provided in the middle of the ash falling pipe main pipe 12;

[0009] Furthermore, a closing baffle 13 is provided at the inner end of the ash falling pipe main pipe 12;

[0010] Furthermore, a sealing box 14 is provided at the connection between the other end of the ash falling pipe main pipe 12 and the outer surface input end of the separator body conical section 15;

[0011] Furthermore, a baffle is provided inside the front ash hopper 4, and four strip-shaped through holes are evenly opened on the upper surface of the baffle along the length direction;

[0012] Furthermore, the baffle is fixedly connected to the inner wall of the front ash hopper 4 via reinforcing ribs around the baffle;

[0013] Furthermore, when in use, the pressure of the horizontal section of the separator inlet flue is -100Pa under low load conditions, while the pressure at the separator conical section is -1000pa. The different pressure difference between the two is used as power, and an ash hopper and an ash dropping pipe are arranged between the two to transport the ash accumulated in the horizontal section of the inlet flue to the conical section of the separator, so as to achieve the purpose of ash transportation at the inlet section; a gravity flap valve is arranged at the lower part of the ash hopper, which can be opened and closed according to the weight of the ash accumulated in the ash hopper, and the ash in the ash hopper is discharged into the conical section of the separator through the ash dropping pipe. The front ash hopper and the rear ash hopper are arranged front and back. It is a parallel system and can operate independently. In order to prevent ash accumulation in the ash falling pipe, a compressed air purge pipe is set at the turning point of the ash falling pipe to prevent ash blockage in the ash falling pipe. At the same time, an expansion joint is arranged on the ash falling pipe to eliminate the expansion at the connection between the ash falling pipe, the ash hopper and the tapered section of the separator. The mixed flue gas enters the separator tangentially from the separator flue inlet section for flue gas separation. The ash particles are deposited in the tapered section under the action of gravity, and then enter the return valve and return to the bottom of the fluidized bed through the return valve pipeline. The clean flue gas is discharged through the outlet pipe and enters the heat exchanger for heat exchange.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The present invention overcomes the shortcomings of the prior art. The pressure of the horizontal section of the separator inlet flue is -100Pa under low load conditions, while the pressure at the separator conical section is -1000pa. The different pressure difference between the two is used as power. An ash hopper and an ash dropping pipe are arranged between the two to transport the ash accumulated in the horizontal section of the inlet flue to the conical section of the separator, so as to achieve the purpose of ash transportation at the inlet section. A gravity flap valve is arranged at the lower part of the ash hopper, which can be opened and closed according to the weight of the ash accumulated in the ash hopper, and the ash in the ash hopper is discharged into the conical section of the separator through the ash dropping pipe. The front ash hopper and the rear ash hopper are arranged front and back, which belongs to a parallel system. , can operate independently; in order to prevent ash accumulation in the ash falling pipe, a compressed air purge pipe is set at the turning point of the ash falling pipe to prevent ash blockage in the ash falling pipe. At the same time, an expansion joint is arranged on the ash falling pipe to eliminate the expansion at the connection between the ash falling pipe, ash hopper and the tapered section of the separator; the mixed flue gas enters the separator tangentially from the separator flue inlet section for flue gas separation, and the ash particles are deposited in the tapered section under the action of gravity, and then enter the return valve and return to the bottom of the fluidized bed through the return valve pipeline. The clean flue gas is discharged through the outlet pipe and enters the heat exchanger for heat exchange, thereby improving the safety and reliability of the separator operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a front view of an ash removal system for ash accumulation at a flue inlet section of a fluidized bed separator according to the present invention;

[0017] Figure 2 It is a side sectional view of an ash removal system for ash accumulation at a flue inlet section of a fluidized bed separator according to the present invention;

[0018] Figure 3 yes Figure 1 A partial sectional view taken along line AA of an ash removal system for ash accumulation at a flue inlet section of a fluidized bed separator according to the present invention. DETAILED DESCRIPTION

[0019] Specific implementation method 1: Combination Figures 1 to 3 The present embodiment is described. The present embodiment is a dust removal system for dust accumulation at the flue inlet section of a fluidized bed separator, which comprises a separator inlet section 1, a flue expansion joint 2, a separator inlet docking flange 3, a front ash hopper 4, a rear ash hopper 5, a gravity flap valve 6, a transition section 7, an expansion joint 8, a front ash falling pipe 9, a rear ash falling pipe 10, an ash falling pipe main pipe 12, a separator body tapered section 15, a separator body straight section 16 and a separator outlet section 17;

[0020] One end of the separator inlet section 1 is connected to one end of the separator inlet docking flange 3 through the flue expansion joint 2, and the other end of the separator inlet docking flange 3 is connected to the input end of the separator body straight section 16, the top output end of the separator body straight section 16 is connected to the separator outlet section 17, and the bottom output end of the separator body straight section 16 is connected to the top of the separator body conical section 15, and the outer surface bottom of the separator body conical section 15 is provided with a front ash hopper 4, and the outer surface bottom of the separator inlet section 1 is provided with a rear ash hopper 5, and the front ash hopper 4 and the rear ash hopper 5 are connected to the separator body conical section 15. The bottom output end of the hopper 5 is provided with a gravity flap valve 6, a transition section 7 and an expansion joint 8 in sequence along the height direction. The bottom end of the expansion joint 8 connected to the bottom of the front ash hopper 4 is connected to the top of the front ash falling pipe 9, the bottom end of the ash falling pipe 9 is connected to one end of the ash falling pipe main pipe 12, and the other end of the ash falling pipe main pipe 12 is connected to the outer surface input end of the separator body conical section 15. The circumferential outer surface of the front ash falling pipe 9 is processed with through holes, and the through holes on the outer surface of the front ash falling pipe 9 are connected to the bottom of the expansion joint 8 at the bottom connection of the rear ash hopper 5 through the rear ash falling pipe 10;

[0021] In this specific implementation method, an opening area is arranged at the bottom of the separator flue inlet section, and the opening area covers the entire horizontal section of the inlet flue, and is separated by an expansion joint in the middle, and is divided into two areas; the ash hopper is welded and fixed to the bottom of the flue inlet section, and is welded and fixed to the bottom of the inlet section flue with a reinforcing rib plate on the outside of the ash hopper, and the lower part of the conical ash hopper is connected and fixed to the gravity flap valve, and the gravity flap valve automatically opens under the gravity of the accumulated ash, and the counterweight system automatically resets the valve plate after the accumulated ash falls, completing the transportation of the accumulated ash; the gravity flap valve is connected to the expansion joint at the lower part through a transition section, and the expansion joint is connected to The front ash pipe and the rear ash pipe are connected. The front ash pipe and the rear ash pipe are arranged in parallel and finally merged into the ash main pipe. A compressed air pipe is arranged at the turning point of the rear ash pipe. Compressed air is passed into the pipe. The solenoid valve switch arranged on the pipeline is used to control the entry of compressed air to blow away the accumulated ash in the ash pipe to ensure the normal ash transportation. The accumulated ash enters the ash main pipe after the front ash pipe and the rear ash pipe merge. A compressed air pipe is arranged at the turning point of the ash main pipe. The entry of compressed air is controlled by the solenoid valve switch to blow away the accumulated ash in the pipeline. An expansion joint and a closing baffle are arranged on the ash main pipe. The expansion joint is mainly used to absorb the expansion of the pipeline. The closing baffle is mainly used to isolate the fly ash at the bottom of the separator from entering the ash main pipe. The accumulated ash enters the tapered section of the separator through the ash main pipe. The ash main pipe is connected to the tapered section of the separator body through a sealing box, and the sealing box is filled with insulation material. The separator consists of a separator vertical section, a separator conical section, a separator outlet section and a separator flue inlet section. Flue gas enters the separator through the separator flue inlet section. The ash particles settle to the separator conical section by the separator action of the separator, and the dust-free flue gas enters the tail flue through the separator outlet section to exchange heat with the heating surface. The separator flue inlet section is connected to the separator through a flange plate, and a flue expansion joint is arranged in the inlet section flue to absorb the expansion of the separator body and the flue.

[0022] Specific implementation method 2: Combination Figures 1 to 3 To explain this embodiment, this embodiment is a further limitation of the ash removal system described in the specific embodiment 1. This embodiment describes an ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator, and a compressed air pipe 11 is provided at the bottom connection of the expansion joint 8 at the bottom connection of the rear ash dropping pipe 10 and the rear ash hopper 5.

[0023] Specific implementation method three: Combination Figures 1 to 3 This embodiment is described. This embodiment is a further limitation of the ash removal system described in the first embodiment. This embodiment is an ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator. A compressed air pipe 11 is provided at the connection between the bottom end of the ash removal pipe 9 and one end of the ash removal pipe main pipe 12.

[0024] In this specific embodiment, a compressed air pipe 11 is provided at the connection between the bottom end of the ash dropping pipe 9 and one end of the ash dropping pipe main pipe 12, and a compressed air pipe 11 is provided at the bottom connection of the expansion joint 8 where the rear ash dropping pipe 10 is connected to the bottom of the rear ash hopper 5, so as to effectively prevent ash accumulation in the ash dropping pipe.

[0025] Specific implementation method four: Combination Figures 1 to 3 The present embodiment is described as a further limitation of the ash removal system described in the first embodiment. The present embodiment describes an ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator, wherein an expansion joint 8 is provided in the middle of the ash removal pipe main pipe 12.

[0026] Specific implementation method five: Combination Figures 1 to 3 The present embodiment is described as a further limitation of the ash removal system described in the fourth embodiment. The present embodiment describes an ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator, wherein the inner end of the ash removal pipe main pipe 12 is provided with a closing baffle 13.

[0027] Specific implementation method six: Combination Figures 1 to 3 This embodiment is described as a further limitation of the ash removal system described in the fifth embodiment. This embodiment is an ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator. A sealing box 14 is provided at the connection between the other end of the ash pipe main pipe 12 and the outer surface input end of the conical section 15 of the separator body.

[0028] Specific implementation method seven: Combination Figures 1 to 3 The present embodiment is described as a further limitation of the ash removal system described in the first specific embodiment. The present embodiment describes an ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator. The interior of the front ash hopper 4 is provided with a baffle, and the upper surface of the baffle is evenly provided with four strip-shaped through holes along the length direction.

[0029] Specific implementation method eight: Combination Figures 1 to 3 To explain this embodiment, this embodiment is a further limitation of the ash removal system described in Specific Embodiment 7. This embodiment describes an ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator, wherein the baffle is fixedly connected to the inner wall of the front ash hopper 4 via reinforcing ribs on all sides.

[0030] How it works

[0031] An opening area is arranged at the bottom of the separator flue inlet section, which covers the entire horizontal section of the inlet flue and is separated by an expansion joint in the middle, dividing it into two areas; the ash hopper is welded and fixed to the bottom of the flue inlet section, and the outer side of the ash hopper is welded and fixed to the bottom of the flue inlet section with a reinforcing rib plate, and the lower part of the conical ash hopper is connected and fixed to the gravity flap valve, which automatically opens under the gravity of the accumulated ash, and the weight system automatically resets the valve plate after the accumulated ash falls, completing the transportation of the accumulated ash; the gravity flap valve is connected to the expansion joint at the bottom through the transition section, and the expansion joint is connected to the front ash drop pipe It is connected to the rear ash pipe. The front ash pipe and the rear ash pipe are arranged in parallel and finally merge into the ash main pipe. A compressed air pipe is arranged at the turning point of the rear ash pipe. Compressed air is passed into the pipe. The solenoid valve switch arranged on the pipeline is used to control the entry of compressed air to blow away the accumulated ash in the ash pipe to ensure the normal ash transportation. The accumulated ash enters the ash main pipe after the front ash pipe and the rear ash pipe merge. A compressed air pipe is arranged at the turning point of the ash main pipe. The entry of compressed air is controlled by the solenoid valve switch to blow away the accumulated ash in the pipeline. An expansion joint and a closing baffle are arranged on the ash main pipe. The expansion joint is mainly used to absorb the expansion of the pipeline. The closing baffle is mainly used to isolate the fly ash at the bottom of the separator from entering the ash main pipe. The accumulated ash enters the tapered section of the separator through the ash main pipe. The ash main pipe is connected to the tapered section of the separator body through a sealing box, and the sealing box is filled with insulation material. The separator consists of a separator vertical section, a separator conical section, a separator outlet section and a separator flue inlet section. Flue gas enters the separator through the separator flue inlet section. The ash particles settle to the separator conical section by the separator action of the separator, and the dust-free flue gas enters the tail flue through the separator outlet section to exchange heat with the heating surface. The separator flue inlet section is connected to the separator through a flange plate, and a flue expansion joint is arranged in the inlet section flue to absorb the expansion of the separator body and the flue.

Claims

1. An ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator, characterized in that: It comprises a separator inlet section (1), a flue expansion joint (2), a separator inlet docking flange (3), a front ash hopper (4), a rear ash hopper (5), a gravity flap valve (6), a transition section (7), an expansion joint (8), a front ash drop pipe (9), a rear ash drop pipe (10), an ash drop pipe main pipe (12), a separator body conical section (15), a separator body straight section (16) and a separator outlet section (17); One end of the separator inlet section (1) is connected to one end of the separator inlet docking flange (3) through a flue expansion joint (2), the other end of the separator inlet docking flange (3) is connected to the input end of the separator body straight section (16), the top output end of the separator body straight section (16) is connected to the separator outlet section (17), the bottom output end of the separator body straight section (16) is connected to the top of the separator body conical section (15), a front ash hopper (4) is provided at the bottom of the outer surface of the separator body conical section (15), a rear ash hopper (5) is provided at the bottom of the outer surface of the separator inlet section (1), the front ash hopper (4) and the rear ash hopper (5) are connected to the separator body conical section (15), and the separator body conical section (15) is connected to the separator body conical section (15). The bottom output end of the separator (5) is provided with a gravity flap valve (6), a transition section (7) and an expansion joint (8) in sequence along the height direction; the bottom end of the expansion joint (8) connected to the bottom of the front ash hopper (4) is connected to the top of the front ash dropping pipe (9); the bottom end of the ash dropping pipe (9) is connected to one end of the ash dropping pipe main pipe (12); the other end of the ash dropping pipe main pipe (12) is connected to the input end of the outer surface of the tapered section (15) of the separator body; the circumferential outer surface of the front ash dropping pipe (9) is processed with a through hole, and the through hole on the outer surface of the front ash dropping pipe (9) is connected to the bottom of the expansion joint (8) at the connection point of the bottom of the rear ash hopper (5) through the rear ash dropping pipe (10).

2. The ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator according to claim 1, characterized in that: A compressed air pipe (11) is provided at the bottom connection of the expansion joint (8) at the bottom connection of the rear ash dropping pipe (10) and the rear ash hopper (5).

3. The ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator according to claim 1, characterized in that: A compressed air pipe (11) is provided at the connection between the bottom end of the ash falling pipe (9) and one end of the ash falling pipe main pipe (12).

4. The ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator according to claim 1, characterized in that: An expansion joint (8) is provided in the middle of the ash falling pipe main pipe (12).

5. The ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator according to claim 4, characterized in that: A closing baffle (13) is provided at the inner end of the ash falling pipe main pipe (12).

6. The ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator according to claim 5, characterized in that: A sealing box (14) is provided at the connection between the other end of the ash falling pipe main pipe (12) and the outer surface input end of the separator body conical section (15).

7. The ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator according to claim 1, characterized in that: The front ash hopper (4) is provided with a baffle plate inside, and the upper surface of the baffle plate is evenly provided with four strip-shaped through holes along the length direction.

8. The ash removal system for ash accumulation at the flue inlet section of a fluidized bed separator according to claim 7, characterized in that: The baffle is fixedly connected to the inner wall of the front ash hopper (4) via reinforcing ribs around the baffle.

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