Ash handling system

Summary

The transcript explains the operation of an ash handling system, responsible for managing ash produced after coal combustion in boilers. It describes the key components such as the electrostatic precipitator, fluidized bed, economizer, and air preheater ash systems, all of which transfer collected ash through pipes using compressed air. The ash is stored in silos and can be used in cement production or disposed of after treatment. The system also includes a bottom ash handling process, which involves cooling, crushing, and transferring the ash to a bunker, where it is eventually transported by trucks.

Takeaways

• 😀 The ash handling system manages the ash produced after coal is burned in the boiler.
• 😀 Key components of the ash handling system include the Electrostatic Precipitator Ash, Fluidized Bed Ash, Economizer Ash, and Air Preheater Ash systems.
• 😀 Compressed air from a compressor is used to transport ash through pipes in the system.
• 😀 Ash collected in each system's hopper is transferred to a pump when the valve is opened, and the valve is closed once a certain amount of ash fills the pump.
• 😀 The ash in the pump is moved through pipes by the compressed air, which is provided by the compressor.
• 😀 The MD and AV pumps used in all ash handling systems follow the same process for transporting ash.
• 😀 Ash from the electrostatic precipitator is sent to an ash silo, while ash from the economizer and air preheater is also sent to the silo using compressed air.
• 😀 Ash stored in the silo can be processed in various ways, such as being dried and used as a cement material or mixed with service water to form wet ash.
• 😀 Wet ash is transported by trucks after being processed in the wet conditioner.
• 😀 The bottom ash handling system collects, cools, and crushes bottom ash before delivering it to a bottom ash bunker for manual disposal into trucks.
• 😀 The drag chain conveyor used in the bottom ash system keeps water at a specific temperature to cool the hot bottom ash as it drops from the boiler.

Q & A

What is the purpose of the ash system?

The ash system is designed to handle the ash produced after coal is fired at the boiler. It includes various sub-systems like the electrostatic precipitator ash system, fluidized bed ash system, economizer ash system, and air preheater ash system.

How is the compressed air involved in the ash system?

Compressed air, which is generated by a compressor, is sent through pipes to the ash system. It helps transfer the collected ash from each system to the ash silo or other storage areas.

What happens to the ash once it is collected in the hopper?

Once the ash is collected in the hopper, it is transferred to the pump after opening the valve. The valve is then closed to prevent additional ash from entering the pump until a certain amount is accumulated.

How is the ash transferred through the system?

The ash is transferred through pipes using the compressed air from the compressor. This process occurs not only for the electrostatic precipitator ash but also for ash from other systems, such as the economizer and air preheater.

Where is the transferred ash sent?

The transferred electrostatic precipitator ash is sent to the ash silo. The economizer ash and air preheater ash are also directed to the same ash silo using compressed air.

What happens to the ash stored in the ash silo?

The ash stored in the ash silo is sometimes used as a material for cement production after being dried at the dry unloader. Additionally, some of the ash is carried out by trucks for disposal or further processing.

What is the role of the wet conditioner in the ash system?

The wet conditioner is used to mix the ash with service water, creating a wet ash mixture (known as 'weds ash') for further processing or disposal.

What is the function of the bottom ash handling system?

The bottom ash handling system collects, cools, and crushes the bottom ash from the furnace, then delivers it to the bottom ash bunker for disposal or further processing.

How is the bottom ash cooled?

The hot bottom ash is cooled when it drops into water in the drag chain conveyor. The upper part of the conveyor is always filled with water at a controlled level to ensure the ash is cooled properly.

What happens to the crushed bottom ash?

The crushed bottom ash is transferred to the bottom ash bunker, where it is manually disposed of and carried away by trucks periodically.