BARH STPP-I (3 x 660 MW)

BALANCE WORKS OF ASH HANDLING SYSTEM PACKAGE

SALIENT TECHNICAL FEATURES

1.ASH HANDLING SYSTEM

Ash Handling System shall consist of the following sub systems:

a)Bottom Ash Handling System

Jet pump and Water Impounded Hopper System – An intermittent system consisting of water impounded hoppers, clinker grinders, jet pumps etc.

b)Economiser and Air Pre-heater Hopper Ash Handling System

Economiser ash and Air preheater ash is handled through wet system, using flushing apparatus and the slurry is led to the ash slurry trench, which gets connected to the combined ash slurry pump house.

c)Bottom Ash Hopper Overflow Water System

Over flow water from bottom ash hopper is to be reused in ash handling system. The system comprises of overflow tank, settling tank & surge tank, overflow water transfer pumps and sludge pumps shall be provided.

d)Fly Ash Handling System

Two-stage system for removing ash in dry form from ESP hoppers is envisaged. The ash will be first conveyed from ESP hoppers upto buffer hoppers in each unit by a vacuum conveying system and subsequently from buffer hoppers to Main Silos by a pressure transportation system

i)Vacuum Conveying system

It shall consist of liquid ring vacuum pumps, material handling valves, cast iron pipes for dry ash conveying, instrument air compressors etc.

ii)Dry Fly Ash Transportation system

The system will consist of buffer hoppers, transport air compressors, CI / MS pipes, Structural steel silos, buffer hoppers & silo aeration blowers, dust conditioners, telescopic chutes, water pumps etc.

e)Combined Ash Slurry Disposal System

The bottom ash and fly ash from all three units, shall be transported as lean slurry by slurry duty centrifugal pumps from bottom ash slurry pump house to disposal area.

f)Ash Water System

Ash water system consists of bottom ash HP water pumps, BA LP water pumps, flushing water pump, fly ash HP water pumps, etc.

2.Some equipments for ash handling system are already supplied by the previous contractor and are available as “as-is-where-is” basis for use. Civil works have been partly executed.

3.The scope of work includes balance mechanical, electrical, control & instrumentation works and completion of civil works, structural works and architectural works to provide an integrated ash handling system for three units.