Continuous Collection and Dewatering of Bottom Ash and Coarse Abrasive Material
Bottom ash continually falls from the furnace throat, through the insulated bottom ash chute, and into the water-filled submerged conveyor trough. Cooled ash is conveyed along the bottom of this trough by conveyor flights attached at both ends to continuous loops of conveyor chain. As the ash-laden flights leave the water-filled trough and travel up the dry incline, the ash drains and dewaters itself. The dewatered ash is discharged to a take-away conveyor or storage area. The conveyor flights return in a lower compartment, which is open for maintenance.
System Features & Benefits
- Low-speed operation (8fpm or less) results in very low wear rates.
- Continuous, unattended operation with low power consumption.
- Low water use with zero water discharge systems available.
- On-line access and maintenance of all critical components.
- Completely shop assembled and tested for low erection costs – simple retrofits.
- Variable speed operation and surge capacity for upset conditions.
Proven in Operation at Utility and Industrial Boilers
AshTech has supplied submerged bottom ash conveyor systems on:
- Stoker/grate furnaces burning coal, wood, bio-mass, municipal solid waste, refuse derived fuel, tires, sludge, and combinations of these fuels.
- Fluidized boiler bed ash removal systems.
- Pulverized coal-fired furnaces from under 40MW to over 400MW in size, collecting bottom ash, slag, mill rejects, and economizer ash. Ash is sized or crushed, and transported to storage bunker or silo for truck loading.
Conveyors in operation range in capacity from under 5TPH to over 50TPH. Conveyor widths range from 2 ft to over 6 ft, with conveyor lengths up to a maximum of 200 ft. System retrofits can be accomplished with as little as 3 ft clearance under furnace outlet.