Ash Handling SystemWhat are the types of Ash in Thermal Power Plant ?

Bottom Ash

Fly Ash

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Bottom AshThe ash which is directly collected

from bottom of boiler.

Bottom ash directly falls down in water filled bottom due to gravity.

Bottom ash is 20% of total ash.

Fly AshIt is collected from :-1-ESP hoppers2-Air preheaters hoppers3-Economiser hoppers

It is 80% of total ash.

Wet systemIn this system ash conveying

media is water.It has two main component:-

1-Hydro-vactor2-Hydro-ejector

Hydro-vactorWorking Principle:-

Hopper ash is directly sucked by vaccum, which is created by high water Jet (hydrovactor).This ash mix with water in collecting tank and finally slurry collects in slurry sump.

Hydro-ejectorWorking Principle:-

High pressure water jet carries slurry from the bottom to slurry sump.

This system operates once in a day (24 hrs).

Final disposal of slurryFinally slurry from slurry sump is

conveyed by pair of big centrifugal pumps to Ash ponds.

This slurry system is common –1-for D & E station2-for C & F station

Fly Ash in Forestry

Ash pond No –1

Fly Ash in Forestry

Ash pond No –1

Fly Ash in Forestry

Ash pond No –2

Different Auxillaries in wet system (‘F’station)

1-H.P. pump 3 Nos. 11 kg/cm2

2-L.P. pump 3 Nos. 6 kg/cm2

3-Ash slurry pump 3 Nos. in each path 2.5 kg/cm2

4-Air washer pump 2 Nos. 5 kg/cm2

5-Seal water pump 2 Nos. 18 kg/cm2

What is the need of dry system?

It has some good characteristics over the wet system:-

1-Huge quantity of water is saved.2-Power consumption is less.3-Reduction in surface pollution.4-Earning, by selling dry ash to cement

factory & bricks manufacturer.

Components of dry system

K-pumpP.D.pumpCentac compressorAcher silo

K-pumpIt is nothing but the combination of

silo,Transfer vessel,Dispencing vessel &

Centrifugal compressor.D & E station has common K-pumpC & F station has another common

K-pump.

Working Principle of K- pump

It works on the principle of pressure difference.

It’s operation is sequential ,because Dome Valves from DV-1 to DV-6 operate in sequence.

Acher SiloFinally Dry ash is disposed to acher

silo which is located in AEC campus.

These are 2 in nos.

Each has capacity of 750 ton .

INTEGRATED FLY ASH HANDLING SYSTEM: (Schematic flow diagram)Stage- I

C stn. F stn.Fly ash Fine Ash Fly ashHoppers Silo (New) Hoppers

130 Cu.Mtr.( 'C' stn)

30 TPH

(After rehibilitation) Stage-II 80 TPH

80 TPH

Stage-I

Fine AshSilo (New) E stn. D stn.

130 Cu.Mtr. Fly ash Fly ash('D/E' stn) Hoppers Hoppers

80 TPH

80 TPH

Stage-II 80 TPH

To final ash disposal area by closed tanker / truck

Exist.Recip Compr Compr.

FINAL FLY ASH STORAGE SILO AT

ACHER

Capacity : 750 Cu.Mtr.

FINAL FLY ASH

STORAGE SILO AT ACHER

Capacity : 750 Cu.Mtr.

Stage II CentrifugalCo

mpr.

C 1 Existing Silo

(Cap:350 T)

F stn. Intm.

Hopper

D/E Exist. RCC Silo

(Cap :450 T)

Stage I Centrifugal

Compr.

Stage I Centrifugal

Compr.

Stage II Centrifugal

Compr.

Loading of trucks & tankers at acher

There are 2 system of loading :-

1-For truck - water spray system2-For tankers – by gravity

Dry Ash unloading at Acher

Ash collection in closed tanker at Acher silo

Dry Ash unloading at Acher

Ash collection in closed tanker at Acher silo

Use of Fly AshFor building constructionFor Cement manufacturingFor bricks manufacturing Ash customers:-1-Gujrat ambuja cement2-Binani cement, laxmi cement3-GCL (RCC pipe mfg.)

Fly Ash used in Bldg. Mat.

Private Private Private Bungalow Gadhinagr

Fly Ash used in Bldg. Mat.

Ghodasar Shriji Complex

Ash used in RCC road Construction

RCC road near D.M. Plant area

Ash used in RCC road Construction

RCC road from Crusher house to Coal JN - M

Future strategiesNow a days we are using almost dry

system.In future our planning is to stop

whole wet system except bottom ash which is only 20%.

For loading trucks & tankers we are thinking about loading in night shift too.