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Chain conveyor troubleshoot guide

  Problem Identification & Corrective Action Sl No. Problem Potential Cause Solution 1 Chain rises off from sprocket 1.Excess chain slack. 2.Excess wear at the bases of sprocket teeth. 3.Excess chain extension. 4.Foreign material stuck to the bases of sprocket teeth. 5.Reverse rotation of conveyor 6.Uneven chain tightening of chain 1.Adjust the amount of slack equally at both sides. 2.Carryout hard facing of the sprockets 3.Replace the elongated chain parts. 4.Remove the foreign material from the bases of the teeth. 5.Avoid reverse rotation of the conveyor when chain tightened is uneven 2 Chain separates poorly from the sprocket. 1.Sprocket misalignment. 2.Excess chain slack. 3.Excess wear at the bases of sprocket teeth. 4.Uneven chain tightening of chain 1-Adjust alignment. 2-Adjust the amount of slack.

How do you preserve the power plants equipments in long shutdown??

POWER PLANT EQUIPMENTS LONG SHUTDOWN PRESERVATION METHODS
SL NO.
EQUIPMENT
PRESERVATION METHOD
A
MECHANICAL

1
Boiler
1-Wet preservation (If shutdown period is up to one month)
Maintain pH: 10-10.5
Hydrazine concentration :> 200 ppm
Note: Check water sample at various locations like steam drum, mud drum, super heater, economiser & Water wall tubes. Concentration should be same at all collection points
2-Dry Preservation (If shutdown period is more than one month)
2
Deaerator & Surge tanks
Wet preservation
Maintain pH: 10-10.5
Hydrazine concentration :>200 ppm
3
Travelling grate (TG)
After cleaning, inspection & Maintenance, keep run TG at least 10-15 minutes on every 6-7 days to avoid shaft jam in bush/bearings
4
ESP
After cleaning & Inspection, close all the man hole doors air tight & keep lime trays at various locations to avoid moisture accumulation on internals
5
APH & Economiser
After cleaning & Inspection, close all man hole doors air tight & keep lime trays at various locations to avoid moisture accumulation on internals
6
Boiler fans
After cleaning & Inspection..close all man hole doors air tight
Change the shaft orientation at every 10-15 days by rotating shaft manually to avoid shaft sagging/bending
7
Boiler feed pumps
Keep suction valve open
Change the shaft orientation at every 10-15 days by rotating shaft manually to avoid shaft sagging/bending
8
Air Compressors
Operate Air compressors at least 10-15 minutes at every 7-8 days or else rotate the flywheel one complete rotation
9
Main & Auxiliary cooling water pump
Rotate the shaft on every 10-15 days to avoid impeller jam in wear ring
10
Steam Turbine
1-Turbine dehumidification by blowing hot air through Turbine HP suction to LP suction & ensure relative humidity in Turbine is <40%
2-Put turbine on barring gear for 20-30 minutes at every 6-7 days
3-Operate HP & LP valves from 0 to 100% at every 15 days
4-Operate ESV at every 15 days
11
Turbine lub oil system
Keep "ON" oil centrifuge at least twice in a week
12
Ash handling system
Ensure all ash handling & storage systems are clean to avoid rusting/corrosion
13
Fuel feeding system
Maintain fuel feeding system internals clean to avoid corrosion & rusting
B
E&I

1
Generator
Keep "ON" Generator space heaters for 8-10 hours if atmosphere temperature is very less (In rain & winter seasons)
2
Power Transformer
Charge transformers at least 6-8 hours at every week to avoid moisture formation in oil
3
VFD drives
Keep charged all VFD drives continuously
Note: Avoid interruption of power supply to VFDs
4
Batteries
Inspect battery voltages regularly (twice in a month)
5
UPS & AVR
Check Healthiness of redundancy systems regularly
6
Motors
1-Cover all motors terminals by polythene covers to avoid entry of rain water
2-For higher KW motor keep "ON" space heaters
7
MCC & PCC
Keep lime trays at MCC, PCC to avoid moisture formation
8
DCS
Ensure DCS healthiness regularly
Note: If DCS kept OFF, inspect the panels regularly to ensure rats/lizards are not entering into the panels
C
WTP

1
RO plant
Preserve RO membranes with 2-3% SMBS or other chemical for 30-40 days. After that drain  the preserved water & perform membrane flushing on every 7-8 days
2
Cooling tower
If CT is not necessary in shutdown, drain the cooling tower ,clean the sumps & apply lime
3
Cat ion & Anion Resin
Maintain normal water level in vessels
Replace the vessels water at every 10-15 days
D
SAFETY

1
Fuel yard & Fuel handling
Depute a particular person to have daily round to avoid fire incidents due to saturation of coal/bagasse or any other fuel
2
Fire fighting system
Conduct fire fighting pumps trial (especially Diesel fire fighter pump & Main fire fighter pump) to ensure healthiness
3
Plant fire alarm system
Check Healthiness of fire alarm systems  regularly

Comments

  1. Sir can we keep storage tanks and deaerator in dry conditions sealing all man hole doors.

    ReplyDelete

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