ASH HANDLING SYSTEMS

BySudeepEEPL

ASH HANDLING

• Method of collection, conveying, interim storage and load out of various types of ash residue

• The most common types of ash include bottom ash (30-40% in FBC) and fly ash (60-70% in FBC) resulting from the combustion

BOTTOM ASH HANDLING

BOTTOM ASH HANDLING SYSTEMS

WATER IMPOUNDED

HOPPER

SUBMERGED SCRAPER

CONVEYORDRY BOTTOM ASH

SYSTEMS

WET DISPOSAL WET DISPOSAL DRY COLLECTION

WATER IMPOUNDED HOPPER

• Very old process and huge amount of water is consumed

• The hopper system receives, quenches, stores crushes and remove bottom ash using hydraulic means

• Ash is discharged once in 6 to 8 hours and hence all the equipment must be designed for 6 to 8 times

WATER IMPOUNDED HOPPER

RECIRCULATION SYSTEM

RECIRCULATION SYSTEM

BOTTOM ASH HANDLING-SSC

1`

SUBMERGED SCRAPER CONVEYOR

• Water submerged drag chain conveyor is placed beneath the furnace

• The wet slurry is taken up to a de-watering slope before discharging to conveyors or silos

• Water serves as cooling medium hence safe disposal and increased life of the conveyor

• Water also acts as airlock for ash hoppers to avoid air to enter the furnace

ADVANTAGES OF SSC

• Reduced water usage• Reduced power consumption• Reduced operational and maintenance cost

PARTS USED IN BOTTOM ASH HANDLING

Submerged scraper conveyor Ash clinker grinder

Dry bottom ash handling

• Water is not used and ash is transferred in dry condition

• Increased boiler efficiency achieved and reduces impurities in stack

• Low maintenance cost and no water required

Dry bottom ash handling

ADVANTAGES OF DRY HANDLING OVER SSC

FLY-ASH HANDLING

FLY-ASH HANDLING

FLY ASH SYSTEMS

PRESSURE CONVEYING SYSTEM

DENSE PHASE

DILUTE PHASE

VACUUME SYSTEM

DILUTE PHASE

PRESSURE SYSTEM

OPERATING PRESSURE IS 5 Kg/cm2

VACUUM SYSTEM

OPERATING PRESSURE IS 530mm

COMBINED PRESSURE AND VACUUM SYSTEM

Comparison of vacuum and pressure systems