The document discusses the ash handling system at NTPC Dadri power plant. It has three types of ash handling systems: bottom ash, air preheater ash, and fly ash. Bottom ash is collected in hoppers under the furnace and transported to ash ponds in slurry form after grinding. Fly ash is captured by the air preheater, economizer, and ESP and stored in silos. The ashes are then mixed with water to form slurry and pumped via pipelines to the ash disposal site. Proper ash handling is required as thermal power plants produce a large amount of ash as a byproduct of coal combustion.

1. ASH HANDLING
SYSTEM

2. ABOUT NTPC DADRI
NTPC Dadri is a power plant of ntpc
group which has a coal based thermal
plant of 1820 and gas based thermal
plant of 817mw and 5mw solar plant
total 2642 mw.
It is located in gautam budh nagar
district of u.p. about 25 km from
Ghaziabad and 9 km from dadri .

3. About NTPC .....

4. ASH
Ash is the residue remaining after the coal
is incinerated.
Composition ofAsh:
- SiO2 .Al2O3.Fe2O3.CaO.MgO
*.Ash handling refers to the method of
collection,conveying,load out of
various types of ash residue lest over
from solid fuel combustion process.

6. PARTS OF ASH HANDELING SYSTEM
Bottom Ash Handling System
Air Pre Heater ash handling system
Fly ash handling system
Ash slurry disposal system

7. Bottom ash handling
Bottom ash is collected in
bottom hopper located
under the furnace boiler
using jet pumping
system.
The ash is treated with
clinkers and grinders to
normalize the bottom
size.
Then it is transported to
ash pond in slurry form.

8. Air pre heater ....An
air preheater (APH) is
any device designed
to heat air before
another process (for
example, combustion
in a boiler) with the
primary objective of
increasing the
thermal efficiency of
the process
 Air pre heater..

9. Fly ash system
Fly ash is collected in air pre heater
hopper is batch wise evacuated using
pneumatic conveying system.
 The combination of economiser,air-
preheater,Esp are used to capture
and transfer fly ash into fly ash silos.


10. Ash slurry disposal system
 Fly ash and bottom ash silos dump ash onto
conveyor belt.
 These conveyors are used to transport ash to
slurry mixing tank,where it is mixed with water
to create ash slurry.
 Slurry pumps are used to transport ash slurry
ash dyke area via ash slurry transportation
pipes.
For mixing ash slurry high concentration slurry
disposal system are used and transport to ash
disposal sites using carbon steel pipelines.

11. An electrostatic precipitator
(ESP) is a filtration device that
removes fine particles, like dust
and smoke, from a flowing gas
using the force of an induced
electrostatic charge minimally
impeding the flow of gases
through the unit.

12. Requirement of ash handling System
In Thermal Power Plant’s coal is generally
used as fuel and hence the ash is produced
as the byproduct of Combustion.
Ash generated in power plant is about 30-
40% of total coal consumption and hence
the system is required to handle Ash for
its proper utilization or disposal.

13. The ways of flyash utilization include
1. Concrete production, as asubstitute material for
Portland cement and sand
2. Embankments and other structural fills (usually for
road construction)
Waste stabilization and solidification.
•Cement clinkers production - (as asubstitute material for
clay)
•Mine reclamation
•As Aggregate substitute material (e.g.for brick production)
•Agricultural uses: soil amendment, fertilizer, cattle
feeders,soil stabilization in stock feed yards, and
agricultural stakes

15. COOLING TOWER
 **. Cooling towers are heat removal devices
used to transfer process waste heat to the
atmosphere.
 *. In thermal power plant it is used to cool
the circulation water which comes out of the
condenser.
 *. The tower vary in size from hyperboloid
that can be up to 200 m tall and 100 m in
diameter, or rectangular that can be over 40
Meyers tall and 80 meters long .