under-furnace bottom ash handling conveyor systems

Under-furnace bottom ash handling conveyor systems are mechanical systems designed to collect, cool, and transport ash and slag from the bottom of a furnace. They typically use a water-filled trough or a dry-air system to cool the hot ash as it falls from the furnace, followed by a conveyor that moves the material for dewatering, collection, and disposal. Key types include submerged scraper or drag chain conveyors for wet systems and dry-air systems that use less energy and water, with options like scraper conveyors or specialized O-chains for ash collection.

Types of systems
• Submerged Scraper Conveyors (SSC): These are wet systems where a conveyor chain with flights is submerged in a water-filled trough below the furnace.
◦ The hot ash is quenched as it falls into the water.
◦ The conveyor chain scrapes the cooled ash along the bottom of the trough.
◦ The ash is then lifted out of the water and dewatered on an incline before being discharged.

Key functions
Ash cooling: Both wet and dry systems cool the ash to a manageable temperature to reduce dust and prevent damage to downstream equipment.
Ash dewatering: Wet systems remove excess water after the initial cooling process, while dry systems operate with no water.
Ash transport: The conveyor moves the ash from the furnace bottom to storage silos, disposal areas, or further processing for reuse (e.g., in cement or construction).
Advantages and disadvantages
Wet systems:
Advantages: Simpler technology, effective ash quenching, and lower risk of dust emissions.
Disadvantages: Require large amounts of cooling water, can cause corrosion, and may lose energy.

Dry systems:

• • Advantages: More energy-efficient, recover thermal energy, and require no additional water treatment, leading to cost savings.
  • Disadvantages: Can require more complex designs and may have higher initial costs in some cases.