basics of chs

1. PRESENTATION ON COAL
HANDLING SYSTEMS
PREPARED BY:-
ARNAB CHAKRABORTY
MBA-PM

2. INTRODUCTION
• Coal handling system or coal handling plant
(CHS or CHP) are plants used for handling coal
from wagon trippler or from stock pile to feed it
to the boiler (main objective).

3. Contd.....
Coal handling
• Coal needs to be stored at various stages of the
preparation process, and conveyed around the CPP
facilities. Coal handling is part of the larger field of bulk
material handling, and is a complex and vital part of the
CPP.

4. Contd...
Stockpiles
• Stockpiles provide surge capacity to various parts of the CPP. ROM
coal is delivered with large variations in production rate of tonnes
per hour (tph). A ROM stockpile is used to allow the washplant to be
fed coal at lower, constant rate.
• A simple stockpile is formed by machinery dumping coal into a pile,
either from dump trucks, pushed into heaps with bulldozers or from
conveyor booms. More controlled stockpiles are formed
using stackers to form piles along the length of a conveyor,
and reclaimers to retrieve the coal when required for product
loading, etc.
• Taller and wider stockpiles reduce the land area required to store a
set tonnage of coal. Larger coal stockpiles have a reduced rate of
heat loss, leading to a higher risk of spontaneous combustion.

5. Stacker/Reclaimer
• Stacker/ reclaimer is used to stack coal in the
stock pile for future use and reclaimer is used to
reclaim the same coal whenever it is required.
• We often do reclaiming when the coal coming
from the belt feeder is not of the quality to be
feed in boilers.

6. Belt feeder
• It is a conveyor use in carrying coal from the coal
crusher to respective conveyors.
• Crushers:- are used to crush big coals into small
pieces of coal or into standard size (i.e. 50mm
specifically in KSK MAHANADI POWER
PLANT).

7. Coal crushing system
Ring granulator
28-Feb-15

8. Interlocking for safety
• In case of any belt trip, entire system behind except
crusher will stop
• Any other belt of pair will not start on the same
discharge belt except 1A&1B
• Corresponding feeder will trip if any belt trips

9. Cond.....
• Belt & following system except crusher will trip in case of
operation of BSS
• In case of excessive belt slipage, low speed due to over
load or otherwise, belt not running although motor
running, belt snapped than belt and following system
will stop through zeero speed switch
• Overloading of more than 600T/hr
• Motors are protected against over load, short circuit,
single phasing

10. OPERATION OF CHP
• Check if all the belts are healthy and the indication is
green in SCADA.
• Secondly, check for all possible pull chords manually by
sending field operators.
• Take clearance from them and start the siren.
• After 1 min of the siren give start command.

11. SCADA USED IN CHS

12. OPERATION OF PADDLE FEEDER
• The Paddle Feeders feed the coal on the conveyor belt from the
Track hopper at a controlled rate. The paddle blades projected in the
hopper slot scoop the coal from hoppers and discharge it on the
conveyor belt running below.
• The following points need to be checked before taking any paddle
feeder into service.
• a) The paddle arms are free from any obstruction.
• b) There is no leakage at gearboxes and fluid couplings and the oil
levels are correct.
• c) There is no leakage of hydraulic oil, in the case of hydraulically
driven paddle feeders, and the oil levels are correct.
• d) The cable reeling drums for correct winding and unwinding.
• e) The paddle feeder is operating only in interlock mode.

14. OPERATION OF CONVEYOR
• Various conveyors are provided for transporting the coal from Track hopper
to Bunkers.
• The following precautions are to be taken before taking any conveyor into
service:
• a) There is no oil leakage at gearboxes / fluid couplings and the oil levels are
correct.
• b) The Discharge and Receiving chutes are free from jamming and choking.
• c) The Flap Gates are in correct positions.
• d) All inspection doors are in the closed position.
• e) All pull-cords are reset and the EPB is released and ensure that all
protections are healthy.
• f) The Alarm Siren is in working order.
• g) Communication facility is available.
• h) The lighting is adequate.
• i) No Permit To Work (Isolation) is pending against that conveyor.

15. OPERATION OF STACKER/RECLAIMER
• The Stacker Reclaimer is provided to stack the excess coal received
from the mines and to reclaim the coal, as and when required.
• The following points need to be checked before returning Stacker
Reclaimer into service:
• a) The track is clear of obstructions.
• b) There is no leakage from gearboxes, fluid couplings & hydraulic
system. The oil levels are correct.
• c) The availability of power supply is checked.
• d) All operations e.g. travel; slewing, luffing etc. are available.
• e) Brakes are clean and functioning correctly.
• f) CRD cable is free from damage and any obstruction and is
tensioned correctly.

16. 28-Feb-15
THANKS
TYPICAL CHP