Separation system of fly ash from power plant coal-fired boiler wastewater evaporation tower

Abstract

The utility model provides a kind of power plant coal-fired boiler wastewater evaporation tower powder fly ash separation system, including evaporator, first ash shed, multi-tube dust collector, second ash shed and induced draft fan, the bottom of the evaporator is connected with the first ash shed, the flue gas outlet of the evaporator is connected with multi-tube dust collector by first pipeline, the multi-tube dust collector is connected with the air inlet of induced draft fan by second pipeline, the air outlet of the induced draft fan is connected with outlet flue by third pipeline;The bottom of the multi-tube dust collector is connected with the second ash shed, install the separation system on the basis of prior art, so that powder fly ash is further separated before passing through electric precipitation system, effectively reduce the chlorine content of powder fly ash in subsequent process, ensure that the product quality of fly ash meets the sales requirements.

Description

Technical Field

[0001] This utility model relates to the field of separation technology of fly ash from wastewater evaporation towers, and particularly to a separation system for fly ash from wastewater evaporation towers in coal-fired boilers of power plants. Background Technology

[0002] Fly ash is formed when pulverized coal enters a furnace at 1300–1500°C and cools after absorbing heat from the heating surfaces under suspended combustion conditions. Examples include the fine ash collected from flue gas in coal-fired power plants. Based on my country's coal consumption patterns, approximately 250–300 kg of fly ash is produced from burning 1 ton of coal.

[0003] Coal-fired boiler units in power plants treat wastewater through high-temperature evaporation towers. High-temperature flue gas exchanges heat with the atomized wastewater, turning the salt in the wastewater into salt particles. Larger salt particles fall into the ash hopper, while smaller particles are carried away by the flue gas. A certain amount of fly ash remains in the flue gas. The salt particles carried away by the flue gas, when entering the electrostatic precipitator system, can cause the fly ash to exceed chlorine limits.

[0004] There is an urgent need for a separation system for fly ash from the evaporation tower of coal-fired boiler wastewater in power plants, which can further separate fly ash with high salt content before the electrostatic precipitator system. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model proposes a separation system for fly ash from the evaporation tower of coal-fired boiler wastewater in power plants. This system is installed before the electrostatic precipitator system to separate fly ash with high salt content. The solution is as follows:

[0006] A separation system for fly ash from the evaporation tower of a coal-fired boiler in a power plant includes an evaporator, a first ash shed, a multi-tube dust collector, a second ash shed, and an induced draft fan. The bottom of the evaporator is connected to the first ash shed. The flue gas outlet of the evaporator is connected to the multi-tube dust collector through a first pipe. The multi-tube dust collector is connected to the air inlet of the induced draft fan through a second pipe. The air outlet of the induced draft fan is connected to the outlet flue through a third pipe. The bottom of the multi-tube dust collector is connected to the second ash shed.

[0007] Furthermore, a fourth pipe is connected in parallel between the first pipe and the third pipe, and valves are installed on the first pipe, the third pipe, and the fourth pipe.

[0008] Furthermore, an air cannon is connected to the lower side of the multi-tube dust collector via a pipeline. The air cannon is used to blow air with high-speed airflow impact force into the lower part of the multi-tube dust collector. An electric heater is installed at the lower part of the multi-tube dust collector to keep the inside of the multi-tube dust collector dry.

[0009] Furthermore, the inlet and outlet ends of the multi-tube dust collector are connected in parallel with an anti-clogging detection branch. Two anti-clogging samplers are installed on the anti-clogging detection branch, which are located near the inlet and outlet ends respectively. A differential pressure transmitter is also installed on the anti-clogging detection branch, which is located between the two anti-clogging samplers. The differential pressure transmitter is used to detect the differential pressure value before and after the multi-tube dust collector so that operators can promptly detect whether the dust collector is blocked.

[0010] Furthermore, the induced draft fan is also connected to a circulating cooling water pipeline for cooling the fan bearings.

[0011] Furthermore, the induced draft fan is also equipped with a temperature transmitter for detecting the temperature of the induced draft fan bearings.

[0012] Furthermore, the induced draft fan is also equipped with a bearing vibration sensor.

[0013] Compared with the prior art, the advantages of this utility model are as follows:

[0014] This invention connects the flue gas outlet of the evaporator to a multi-tube dust collector, the multi-tube dust collector to the air inlet of the induced draft fan, the air outlet of the induced draft fan to the outlet flue, and the bottom of the multi-tube dust collector to a second ash shed. This technical solution allows for further separation of fly ash with high salt content before it passes through the electrostatic precipitator system, effectively reducing the chlorine content of fly ash in subsequent processes and ensuring that the product quality of fly ash meets sales requirements. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the separation system according to an embodiment of the present invention.

[0016] In the above figures: 1. Evaporator; 2. First ash shed; 3. Multi-tube dust collector; 4. Second ash shed; 5. Exhaust fan; 6. First pipe; 7. Second pipe; 8. Third pipe; 9. Fourth pipe; 10. Air cannon; 11. Electric heater; 12. Anti-clogging detection branch; 13. Anti-clogging sampler; 14. Differential pressure transmitter; 15. Circulating cooling water pipeline; 16. Temperature transmitter; 17. Bearing vibration sensor; 18. Pneumatic valve; 19. Solenoid valve; 20. Ball valve. Detailed Implementation

[0017] To facilitate understanding of this utility model by those skilled in the art, the specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0018] like Figure 1 As shown, this utility model proposes a separation system for fly ash from the evaporation tower of a coal-fired boiler in a power plant, including an evaporator 1, a first ash shed 2, a multi-tube dust collector 3, a second ash shed 4, and an induced draft fan 5.

[0019] The bottom of the evaporator 1 is connected to the first ash shed 2 to separate large salt particles of fly ash, which is stored in the first ash shed 2. The flue gas outlet of the evaporator 1, carrying small salt particles of fly ash, is connected to the multi-tube dust collector 3 through the first pipe 6. The multi-tube dust collector 3 separates the small salt particles of fly ash, which is then stored in the second ash shed 4 connected to the bottom of the multi-tube dust collector 3.

[0020] Multi-tube dust collector 3 belongs to the cyclone dry dust collector category, consisting of many small cyclones connected in parallel within a single housing. The diameter of the cyclones varies from 100 to 250 mm, effectively capturing dust particles of 5–10 μm. The cyclones utilize wear-resistant ceramic tubes, enabling the handling of gases with high dust concentrations. The advantages of multi-tube cyclone dust collectors include high efficiency and large gas throughput.

[0021] The multi-tube dust collector 3 is connected to the air inlet of the induced draft fan 5 via the second pipe 7, and the air outlet of the induced draft fan 5 is connected to the outlet flue via the third pipe 8. The induced draft fan 5 provides power to the first pipe 6 and the second pipe 7, enabling it to quickly transport flue gas from the evaporator 1 into the multi-tube dust collector 3.

[0022] The separation system of this utility model is based on the existing technology. By adding the separation system before the electrostatic precipitator system, it can further separate the fly ash containing salt particles in the flue, effectively reducing the chlorine content of the fly ash in the subsequent electrostatic precipitator system and ensuring that the product quality of fly ash meets the sales requirements.

[0023] Furthermore, a fourth pipe 9, which acts as a bypass pipe, is connected in parallel between the first pipe 6 and the third pipe 8, so that flue gas can pass through when the multi-pipe dust collector 3 is blocked or the induced draft fan 5 malfunctions.

[0024] To facilitate the connection between the main components in the control system, valves are installed on the first pipe 6, the third pipe 8, and the fourth pipe 9. Specifically, in this embodiment, a pneumatic valve 18 is installed on the first pipe 6 to control the connection between the evaporator 1 and the multi-tube dust collector 3; a pneumatic valve 18 is installed on the third pipe 8 to control the connection between the induced draft fan 5 and the flue pipe (the flue pipe is the original structure); and a pneumatic valve 18 is installed on the fourth pipe 9 to control whether the bypass pipe is connected.

[0025] In order to allow the fly ash to enter the second ash shed 4 smoothly, an air cannon 10 is connected to the lower side of the multi-tube dust collector 3 through a pipeline. The air cannon 10 is used to blow air with high-speed airflow impact force into the lower part of the multi-tube dust collector 3. In order to prevent the small salt particles of fly ash in the multi-tube dust collector 3 from clumping or becoming damp, an electric heater 11 is installed in the lower part of the multi-tube dust collector 3. The heater 11 is used to keep the inside of the multi-tube dust collector 3 dry.

[0026] Specifically, a solenoid valve 19 is installed on the connecting pipeline between the air cannon 10 and the multi-tube dust collector 3. Compressed air from the plant area provides the air source for the air cannon 10, and a ball valve 20 is installed on the connecting pipeline.

[0027] To effectively monitor whether the multi-tube dust collector 3 is clogged, an anti-clogging detection branch 12 is connected in parallel at the inlet and outlet ends of the multi-tube dust collector 3. Two anti-clogging samplers 13 are installed on this anti-clogging detection branch 12, located near the inlet and outlet ends respectively. A differential pressure transmitter 14 is also installed on the anti-clogging detection branch 12, positioned between the two anti-clogging samplers 13. This differential pressure transmitter measures the differential pressure across the multi-tube dust collector via the detection branch 12. When the detected value exceeds the maximum design value, an alarm signal is issued, allowing operators to promptly detect whether the dust collector is clogged.

[0028] To prevent the bearing temperature inside the induced draft fan 5 from becoming too high, the induced draft fan 5 is also connected to a circulating cooling water pipe 15 for cooling the bearing of the induced draft fan 5. A temperature transmitter 16 connected to the induced draft fan 5 is used to detect the bearing temperature of the induced draft fan 5. When the bearing temperature of the induced draft fan 5 becomes too high, an alarm signal will be issued to remind the operators to deal with it in time.

[0029] To prevent the induced draft fan from overheating due to excessive vibration, the bearing of the induced draft fan 5 is also equipped with a bearing vibration sensor 17.

[0030] The working principle of the separation system of this utility model is as follows:

[0031] Coal-fired boiler units in power plants treat wastewater through high-temperature evaporation towers, using high-temperature flue gas to exchange heat with atomized wastewater, turning the salt in the wastewater into salt particles. This is a known technology.

[0032] Large salt particles in evaporator 1 fall into the first ash shed 2. Small salt particles in evaporator 1 enter the multi-tube dust collector 3 through the first pipe 6 with the flue gas. At the same time, the induced draft fan 5 works to provide power for the flue gas to enter the multi-tube dust collector 3 quickly. The multi-tube dust collector 3 separates the small salt particles from the fly ash. The separated small salt particles fall into the second ash shed 4. The remaining fly ash is connected to the original outlet flue through the outlet of the induced draft fan 5. The fly ash is then used for other processes through the original outlet flue. These other processes are not the protection points of this application and do not need to be explained here.

[0033] The embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A separation system for fly ash from the evaporation tower of wastewater from a coal-fired boiler in a power plant, characterized in that, The system includes an evaporator (1), a first ash shed (2), a multi-tube dust collector (3), a second ash shed (4), and an induced draft fan (5). The bottom of the evaporator (1) is connected to the first ash shed (2). The flue gas outlet of the evaporator (1) is connected to the multi-tube dust collector (3) through a first pipe (6). The multi-tube dust collector (3) is connected to the air inlet of the induced draft fan (5) through a second pipe (7). The air outlet of the induced draft fan (5) is connected to the outlet flue through a third pipe (8). The bottom of the multi-tube dust collector (3) is connected to the second ash shed (4).

2. The separation system according to claim 1, characterized in that, A fourth pipe (9) is connected in parallel between the first pipe (6) and the third pipe (8), and valves are provided on the first pipe (6), the third pipe (8), and the fourth pipe (9).

3. The separation system according to claim 1, characterized in that, An air cannon (10) is connected to the lower side of the multi-tube dust collector (3) via a pipeline. The air cannon (10) is used to blow air with high-speed airflow impact force into the lower part of the multi-tube dust collector (3). An electric heater (11) is installed in the lower part of the multi-tube dust collector (3). The electric heater (11) is used to keep the inside of the multi-tube dust collector (3) dry.

4. The separation system according to claim 1, characterized in that, The inlet and outlet of the multi-tube dust collector (3) are connected in parallel with an anti-clogging detection branch (12). Two anti-clogging samplers (13) are installed on the anti-clogging detection branch (12). The two anti-clogging samplers (13) are close to the inlet and outlet respectively. A differential pressure transmitter (14) is also installed on the anti-clogging detection branch (12). The differential pressure transmitter (14) is located between the two anti-clogging samplers (13) and is used to detect the differential pressure value before and after the multi-tube dust collector so that the operators can detect whether the dust collector is blocked in time.

5. The separation system according to claim 1, characterized in that, The induced draft fan (5) is also connected to a circulating cooling water pipeline (15) for cooling the bearings of the induced draft fan (5).

6. The separation system according to claim 5, characterized in that, A temperature transmitter (16) is also installed on the bearing of the induced draft fan (5) to detect the temperature of the bearing of the induced draft fan (5).

7. The separation system according to claim 1, characterized in that, The blower (5) is also equipped with a bearing vibration sensor (17).

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