Aph Washing
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AIR PREHEATER WASHING PROTOCOL . All the 4 APH were cleaned by using the FH water as well as the service water Afterwards all the 4 APH were dried by running the ID fan & keeping the manhole open . Activity start time : 10/12/05- 6:00 hrs . Activity Complete Time : 10/12/05- 17:45 hrs . DESCRIPTION SAPH – A SAPH – B PAPH – A PAPH – B Final water quality Visible water O/L quality Clear Clear Clear Clear
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Transcript of Aph Washing
AIR PREHEATER WASHING PROTOCOL .
All the 4 APH were cleaned by using the FH water as well as the service
water
Afterwards all the 4 APH were dried by running the ID fan & keeping the
manhole open .
Activity start time : 10/12/05- 6:00 hrs .
Activity Complete Time : 10/12/05- 17:45 hrs .
DESCRIPTION SAPH – A SAPH – B PAPH – A PAPH – B
Final water quality
Visible water O/L quality
Clear Clear Clear Clear
AIR PREHEATER HOT WASHING TO BE DONE AT 150 DEGREE CEN FLUE GAS INLET TEMP.
PURPOSE: 1. for cleaning the air preheater baskets2. for carrying out internal inspection & repair works
PREPARARION FOR AIR PREHEATER WATER WASHING:1. All air preheater hoppers to be completely emptied and to be checked
physically for any ash deposition. If found to be cleared by poking manually
2. All ESP passes inlet gates to be closed3. All APHs flue gas inlet dampers to be closed4. All APHs air inlet dampers to be closed5. All APHs flue gas outlet dampers to be opened6. All APHs air outlet dampers to be opened7. Flue gas common outlet dampers to be closed8. FD & PA fan discharge dampers to be closed9. All air preheater hoppers manholes to be opened10.Duct manholes in FD & PA fan discharge lines to be opened for watewr
draining. Check physically & remove ash accumulation at manholes.11. Inform the chemist for taking sample12. Inform UCE & SCE for hydrant & service water usage13.Check air motors availability & reliability as air motor to be in service for
complete water washing14.Check water drainage at 0’mtr boiler area15.Obtain clearance from C&I, rotary parts & pressure parts
PROCEDURE:_
1. Start air motor2. Water washing may be done with hydrant or service water pressure.
Water pressure should be more than 6Kgs.3. Only two air preheaters washing to be done simultaneously with single
source of water for better effectiveness4. Open hot end side water valve & keep the valve for 20minutes & then
close the valve & open cold end side valve for 20 minutes , then for change over to hot end side
5. Check free flow of water from APH hoppers & air side duct manholes6. Terminate water washing at PH value 7 & turbidity 507. Usually it takes 8 – 10 hrs for complete water washing of APHs8. Keep air side & flue gas side inlet dampers remain close after water
washing. Other wise fine dust will deposite in APH enclosure & carrying internal inspection & overhauling job will be difficult.
AIR PREHEATER WATER WASHING PARAMETERS
DESCRIPTION SAPH – A SAPH – B PAPH – A PAPH – B
1Flue gas DP
(before)176 179 175 165
2Flue gas DP(After)
105 105 85 85
3Flue gas
outlet temp136 136 145 130
4Water
washing start time
9:30am 12:00am 08:00am 08:00am
5Completion
time11:30pm 11:30pm 02:00 pm 09:00pm
6Service water PH/Turbidity
8/10 8/10 8/10 8/10
7Final water
quality7/85 6.5/80 6.3/90 6.5/95
8Visible water O/L quality
Clear Clear Clear Clear
( B K Sahoo) Sr.Supdt.(OPN)Date: 06/08/2005
