BOILER PROTECTION

AND

INTERLOCKS

S.VISWANATHAN

CONCEPT OF BOILETR PROTECTION AND INTERLOCKS PROTECTIONWhenever the boiler safety is threatened cutting off all fuel supply to boiler to avoid damage to boilerINTERLOCKS Ensure safe sequential operation of various systems and componentsTrip individual equipment incase of abnormalities

S.VISWANATHAN

BOILER PROTECTION

ABNORMALOPERATINGCONDITIONENERGISEMASTER FUEL TRIP RELAYCLOSE ALL OIL TRIP VALVES AND NOZZLE VALVESTRIP ALL R.C FEEDERS AND MILLSTRIP ALL P.A.FANS

S.VISWANATHAN

ABNORMAL OPERATING CONDTIONS CAUSING BOILER TRIPLoss of power supply to BMS / FSSSLess than fire ball and loss of A.C. at any elevation in serviceLoss of all fuel tripFlame failure tripVery very low drum water levelVery very high drum water levelFurnace pressure very very highFurnace vacuum very very high

S.VISWANATHAN

ABNORMAL OPERATING CONDTIONS CAUSING BOILER TRIPBoth I.D. fans trippedBoth F.D. fans trippedAirflow less than 30% and boiler load less than 30%Re heater protectionBoth trip push buttons on console pressed simultaneouslyGenerator tripping on electrical protectionExcessive turbine axial shiftVery very low turbine L.O pressure

S.VISWANATHAN

LOSS OF ALL FUEL TRIPThis protection shall act only after once a minimum of 3 ignitors have been put on at any elevation and if all the following conditions occurAll R.C.feeders are offEither IOTV is not open or more than one of IONVs are not open at all oil elevationsEither HOTV is not open or more than one of HONV s are not open at all oil elevationsEither LOTV is not open or more than one of LONV s are not open at ab elevationAC supply to FSSS is available

S.VISWANATHAN

INTERLOCKS COVERED UNDER FSSS LOGIC PURGE INTERLOCKSINTERLOCKS FOR FUEL OIL VALVESIGNITOR OIL TRIP VALVEWARMUP OIL TRIP VALVEHEAVY OIL TRIP VALVEHEAVY OIL RE-CIRCULATION VALVEINTERLOCKS FOR PULVERISERSINTERLOCKS FOR R.C. FEEDERSINTERLOCKS FOR SY. AIR CONTROLAUXILIARY AIR DAMPERSFUEL AIR DAMPERSINTERLOCKS FOR SCANNER AIR FANSINTERLOCKS FOR IGNITOR AIR FANS------------------------------------------------------------

S.VISWANATHAN

S.VISWANATHAN

PURGE INTERLOCKSFURNACE PURGING CAN BE STARTED ONLY IF THE FOLLOWING PERMISSIVES ARE SATISFIEDALL OIL TRIP VALVES AND NOZZLE VALVES ARE PROVEN CLOSEDALL THE PULVERISERS AND FEEDERS ARE OFFALL THE HOT AIR GATES ARE FULLY CLOSED AND THE COLD AIR DAMPERS ARE LESS THAN 5% OPENALL THE ELEVATION FLAME SCANNERS SHOW NO FLAMEATLEAST ONE ID&FDFANS ARE IN SERVICE AND THE AIR FLOW IS 30% OF FULL LOAD AIR FLOWALL AUXILIARY AIR DAMPERS ARE MODULATING TO MAINTAIN AN ADEQUATE WIND BOX TO FURNACE DIFFERENTIAL PRESSURENONE OF THE BOILER TRIP CONDITIONS EXIT--------------------------------

PURGEREADYPUSH TOPURGE

PURGEONPURGECOMPLETE

S.VISWANATHAN

IGNITOR OIL TRIP VALVEOPENING PERMISSIVESIGNITOR OIL SUPPLY PRESSURE IS ADEQUATE (12.5KSC)ALL THE I.O. NOZZLE VALES ARE PROVEN CLOSEDNONE OF THE BOILER TRIP COMMANDS IS PRESENTPURGE IS COMPLETED

THIS VALVE WILL CLOSE AUTOMATICALLY UNDER ANY OF THE FOLLOWING CONDITIONSBOILER TRIPSIGNITOR OIL HEADER PRESSURE IS LOW (9.1 KSC) FOR MORE THAN 2 SEC. AND ANY I.0 N.V. IS NOT CLOSED------------------------------------------------------------------------------

S.VISWANATHAN

S.VISWANATHAN

WARMUP OIL TRIP VALVEOPENING PERMISSIVESW.O. SUPPLY PRESURRE IS ADQUATE (5.6KSC)ALL W.O NOZZLE VALVES ARE CLOSEDNO BOILER TRIP IMPULSE IS PRESENT PURGE IS COMPLETEDTHIS VALVE WILL CLOSE AUTOMATICALLY UNDER ANY OF THE FOLLOWING CONDITIONS.BOILER TRIP OCCURSW.O. HEADER PRESSURE IS LOW(1.5KSC) FOR MORE THAN 2 SEC. AND ANY W.O.N.V. IS NOT CLOSEDD.P. BETWEEN W.O. AND ATOMISING AIR IS LOW (O.4KSC) FOR MORE THAN 2 SEC., WHEN NO PAIR OF W.O. GUNS ARE IN START UP OR SHUT DOWN AND ANY W.O. N.V. IS NOT CLOSED.

S.VISWANATHAN

HEAVY OIL TRIP VALVE

OPENING PERMISSIVESHEAVY OIL HEADER PRESSURE IS ADEQUATE(9.8KSC)ALL HEAVY OIL NOZZLE VALVES ARE CLOSEDNO BOILER TRIP CONDITION EXISTSPURGE COMPLETETHIS VALVE WILL CLOSE AUTOMATICALLY UNDER ANY ONE OF THE FOLLOWING CONDITIONSBOILER TRIP OCCURSH.O. HEADER PRESSURE IS LOW (1.5KSC) FOR MORE THAN 2SEC. WHEN ANY H.O. NOZZLE VALVE IS NOT CLOSED. D.P. BETWEEN H.O. AND ATOMIS ING STEAM IS LOW (0.4KSC) FOR MORE THAN 2 SEC. WHEN ANY H.O. NOZZLE VALVE IS NOT CLOSED, AND NO H.O. GUN IN START/STOP CONDITION.H.O. TEMP. LOW (105oC) FOR MORE THAN 2 SEC. WHEN ANY H.O. NOZZLE VALVE IS NOT CLOSED.

S.VISWANATHAN

HEAVY OIL RE-CIRCULATION VALVE

THIS VALVE CAN BE OPENED PROVIDED THE H.O. TRIP VALVE AND ALL H.O. NOZZLE VALVES ARE CLOSED. THIS VALVE WILL CLOSE AUTOMATICALLY WHEN ANY OF THE H.O. NOZZLE VALVE IS NOT CLOSED.

HOTVR.C.VALVENRV

S.VISWANATHAN

WARMUP FUEL ON-OFF CONTROL & SUPERVISIONSTART-STOP CONTROLSELECTION OF WARMUP OIL/HEAVY OIL PERMISSIVESALL THE W.U. OIL ANDH.O. NOZZLE VALVES ARE

PROVEN CLOSED IN AB ELEVATIONBOTH PAIR AT THAT ELEVATION HAVE BEEN SHUT DOWNSTARTING THE ELEVATION PERMISSIVESD.C. POWER AVAILABLEIGNITOR OIL TRIP VALVE FULLY OPENWARMUP, OIL TRIP VALVE FULLY OPENANY FEEDER ON OR NOZZLE TILT HORIZONTAL WITH AIR FLOW ADJUSTED BETWEEN 30 TO 40%

S.VISWANATHAN

WARMUP FUEL ON-OFF CONTROL & SUPERVISION (CONTD.)IF PERMISSIVES ARE SATISFIED ELEVATION IS STARTED IN PAIR BASIS BY PUSH BUTTONS INITIATE 90SEC. TRIAL TIME.CORNER RECEIVES START COMMANDSTOPPING THE ELEVATIONINITIATED BY A STOP SIGNALINDIVIDUAL CORNER RECEIVES A STOP COMMAND WITH A TRIAL TIME OF 375 SEC.

S.VISWANATHAN

WARMUP FUEL ON-OFF CONTROL & SUPERVISION (CONTD.)CORNER MONITORINGINDIVIDUAL CORNER WILL BE PUT INTO SERVICE PERMISSIVESTHE CORNER START IMPULSE IS GIVENLOCAL MAINTENANCE SWITCH IN REMOTE POSITIONMANUAL ISOLATION VALVES OF OIL AND ATOMISING MEDIUM ARE OPENSCAVANGE VALVE CLOSEDGUN IS ENGAGED RESPECTIVE IGNITOR IS IN SERVICE*

S.VISWANATHAN

WARMUP FUEL ON-OFF CONTROL & SUPERVISIONINDIVIDUAL CORNER WILL TRIP UNDER CONDITIONSASSOCIATED LOCAL MAINTENANCE CONTROL SWITCH TURNED OFFCLOSING THE W.U. OIL OR ATM. MEDIUM MANUAL ISOLATION VALVESASSOCIATED IGNITOR IS OFF*W.U.OIL GUN NOT ADVANCED**IGNITOR TRIP VALVE CLOSURE**W.U. TRIP VALVE CLOSURE*LOSS OF UNIT D.C. POWER (2 SEC. TIME DELAY)*BOILER TRIP

S.VISWANATHAN

OIL ELEVATION STARTING SEQUENCE(WITH EDDYPLATE IGNITORS) STARTED IN PAIRS (1,3), (2,4)DEPRESSING ONE PAIR START PUSH BUTTON WILL INITIATE 90 SEC. START TIME TRIAL IF PERMISSIVES ARE SATISFIED.IN THE FIRST 10 SEC. ASSOCIATED ELEVATION IGNITORS ARE STARTED*WHEN 3 OUT OF 4 IGNITORS ARE PROVEN ON START COMMAND IS GIVEN TO FIRST CORNERWHEN THE CORNER GETS START COMMAND AND IF ITS ASSOCIATED IGNITOR IS PROVEN ON THE CORNER IS PLACED IN SERVICE BYGUN ADVANCES TO FIRING POSITION.WHEN GUN IS FULLY ADVANCED ATOMISING VALVE OPENWHEN ATOMISING MEDIUM VALVE IS PROVEN FULLY OPEN OIL NOZZLE VALVE OPENS PLACING THE GUN IN SERVICE.

S.VISWANATHAN

OIL ELEVATION STARTING SEQUENCE(CONTD.)AFTER 10 SECONDS START COMMAND IS GIVEN TO OTHER CORNER AND PLACED IN SERVICEAFTER 90 SEC. START TIME TRIAL OF THE PAIR IS COMPLETED, A CORNER TRIP IS INITIATED FOR ANY CORNER WHERE THE NOZZLE VALVE IS NOT PROVEN FULLY OPEN OR ASSOCIATED IGNITOR IS NOT PROVEN ON.90 SEC. AFTER SECOND PAIR START, A MINIMUM OF 3 OUT OF 4 NOZZLE VALVES MUST BE PROVEN FULLY OPEN IN THAT ELEVATIONOTHERWISEUNSUCCESSFUL ELEVATION START ALARM IS INITIATED AT THAT ELEVATION AND OIL GUNS OF THAT ELEVATION ARE SHUT DOWN IN AN ORDERLY FASHION.

S.VISWANATHAN

OIL ELEVATION STARTING SEQUENCE(WITH HEA IGNITORS)STARTED IN PAIRS (1,3), (2,4)DEPRESSING ONE PAIR START PUSH BUTTON WILL INITIATE 90 SEC. START TIME TRIAL IF PERMISSIVES ARE SATISFIED.ON RECEIVING PAIR START COMMAND IGNITOR ADVANCESIGNITOR TRANSFORMER ENERGISESATOMISING NOZZLE VALVE OPENSOIL NOZZLE VALVE OPENSIGNITOR TRANSFORMER DE ENERGISESIGNITOR RETRACTSDISCRIMINATING SCANNAR PICKS FLAME---------------------------------------------------------------

S.VISWANATHAN

PULVERISER INTERLOCK

S.VISWANATHAN

PULVERISER INTERLOCKSTART PERMISSIVESMILL DISCHARGE VALVES ARE OPENSEAL AIR VALVE IS OPENCOLD AIR DAMPER IS OPENR.C.FEEDER INLET DAMPERS ARE OPENTRAMP IRON HOPPER VALVE IS OPEND.C.POWER TO FSSS IS AVAILABLEBURNER TILT IN HORIZONTAL POSITION AND BOILER AIR FLOW ADJUSTED BETWEEN 30 TO 40% OF FULL LOAD AIR FLOWMILLOUTLET TEMP. IS LESS THAN 930C P.A.PRESSURE IS ADEQUATEEITHER A MINIMUM OF 3 NEXT IMMEDIATE HO/LO NOZZLE VALVES ARE OPEN OR NEXT IMMEDIATE ELEVATION MILL IS WORKING AT GREATER THAN 50% LOAD AND BOILER LOAD IS GREATER THAN 30%

S.VISWANATHAN

PULVERISER INTERLOCKWHEN MILL IS STARTED IMPULSE SHALL BE GIVEN FOR

PERMISSION TO OPEN HOT AIR GATEPERMISSION TO START R.C. FEEDERPERMISSION FOR REGULATORS IMPULSE TO ACT ON HOT AIR DAMPER

S.VISWANATHAN

PULVERISER INTERLOCKPULVERISER WILL TRIP AUTOMATICALLY UNDER ANY OF THE FOLLOWINGBOILER TRIPSLOSS OF UNIT D.C.SUPPLY FOR MORE THAN 2 SEC.MILL DISCHARGE VALVES ARE NOT OPENIF IGNITION ENERGY PERMISSIVE DISAPPEARS BEFORE 180 SEC. FROM FEEDER STARTPRIMARY AIR TRIPWHEN BOTH P.A.FANS TRIPP.A.DUCT PRESSURE FALL BELOW LOW SET POINT FOR 5 SECP.A.DUCT PRESSURE FALL BELOW VERY LOW SET POINTWHEN ONE P.A. FAN TRIPS AND THREE OTHER TOP ELEVATION MILLS ARE IN SERVICE

S.VISWANATHAN

PULVERISER INTERLOCKWHEN A MILL IS TRIPPED IMPULSE SHALL BE GIVEN FOR

TO TRIP THE R.C. FEEDER MOTORTO CLOSE THE HOT AIR GATETO DISCONNECT THE REGULATORS IMPULSE AND CLOSE HOT AIR DAMPERTO PERMIT CLOSING OF MILL DISCHARGE VALVESTO BRING COLD AIR DAMPER TO MINIMUM

S.VISWANATHAN

PULVERISER INTERLOCKHOT AIR GATEHOT AIR GATE WILL OPEN ONLY IF MILL IS ONIF THE HOT AIR GATE IS OPEN IMPULSE SHALL BE GIVEN TO RELEASE HOT AND COLD AIR DAMPER CONTROL TO REGULATEHOT AIR GATE WILL CLOSE AUTOMATICALLY AFTER 30 SEC. UNDER ANY OF THE FOLLOWING CONDITIONSMILL IS TRIPPEDMILLOUTLET TEMP. IS VERY HIGHR.C. FEEDER STOPS WITHIN 5SEC. OF ITS STARTWHEN HOT AIR GATE IS CLOSED IMPULSE SHALL BE GIVEN FOR OPENING THE COLD AIR DAMPER PROVIDED IF THE MILL IS ON

S.VISWANATHAN

R.C. FEEDER INTERLOCKSTART PERMISSIVESNO BOILER TRIP CONDITION PREVAILSELEVATION A.C. AND D.C. ARE AVAILABLEIGNITION ENERGY IS AVAILABLEMILL IS ONHOT AIR GATE IS OPENFUEL AIR DAMPERS ARE CLOSEDNO STOP SIGNAL

S.VISWANATHAN

R.C. FEEDER INTERLOCKON STARTING R.C. FEEDER IMPULSE SHALL BE GIVEN FORTO INCLUDE FEEDER OUTLET IN TOTALISING CIRCUIT AFTER 15 SEC.TO RELEASE FEEDER SPEED CONTROL TO AUTO AFTER 50 SEC.TO MODULATE FUEL AIR DAMPERS ACCORDING TO FEEDER SPEED AFTER 50 SEC.TO PERMIT FEEDER SPEED VARIATOR TO MOVE

S.VISWANATHAN

R.C. FEEDER INTERLOCKR.C. FEEDER SHALL TRIP AUTOMATICALLY UNDER ANY ONE OF THE FOLLOWING CONDITIONSBOILER TRIPS ELEVATION A.C. / D.C. FAILSIGNITION ENERGY DISAPPEARS BEFORE 180 SEC FROM THE STARTING OF FEEDERMILL TRIPSLOSS OF COAL FLOW AND MILL AMP. LOW{ONLY AFTER 5 SEC FROM FEEDER START}

S.VISWANATHAN

R.C. FEEDER INTERLOCKWHEN R.C. FEEDER TRIPS IMPULSE SHALL BE GIVEN FORCLOSING HOT AIR GATEIF EITHER MILL AMP. IS ABOVE MAXIMUM SET POINT OR BOWL D.P. IS HIGH IMPULSE SHALL BE GIVEN FORBRINGING R.C.FEEDER SPEED TO MINIMUM

S.VISWANATHAN

S.VISWANATHAN

INTERLOCKS FOR SY. AIR CONTROLAUXILIARY AIR DAMPERSDURING PURGING AND UPTO 30% LOAD ALL THE AUXILIARY AIR DAMPERS MODULATE TO MAINTAIN WIND BOX TO FURNACE DIFFERENTIAL PRESSURE OF APPROX. 40 MM WCL. (LOW SET PT.)WHEN LOAD EXCEEDS 30% THE D.P SET POINT IS CHANGED TO APPROX. 100 MMWC (HIGHER SET PT.) SIMULTANEOUSLY THE AUX. AIR DAMPERS ASSOCIATED WITH COAL OR OIL ELEVATION NOT IN SERVICE CLOSE IN TIMED SEQUENCE STARTING FROM UPPER ELEVATIONS.ALL THE AUX. AIR DAMPERS MAINTAIN STATUS QUO UPON BOILER TRIP AND OPEN FULLY WHEN BOTH F.D. FANS ARE OFF.

S.VISWANATHAN

THE AUX. AIR DAMPERS ASSOCIATED WITH OIL ELEVATIONS MODULATE AS A FUNCTION OF OIL HEADER PRESSURE WHEN OIL IS BEING FIRED AT THAT ELEVATION. OTHERWISE THEY OPEN OR CLOSE WITH THE BALANCE OF THE AUX. AIR DAMPERS.

FUEL AIR DAMPERSFUEL AIR DAMPERS OPEN 50 SEC. AFTER THE ASSOCIATED FEEDER IS STARTED AND MODULATE AS A FUNCTION OF FEEDER SPEED. FUEL AIR DAMPERS CLOSE, 50 SEC. AFTER THE TRIPPING OF ASSOCIATED R.C. FEEDER ALL THE FUEL AIR DAMPERS OPEN FULLY WHEN BOTH F.D. FANS ARE OFF.

INTERLOCKS FOR SY. AIR CONTROL (CONTD.)

S.VISWANATHAN

INTERLOCKS FOR SCANNER AIR FANSSCANNER AIR FAN WILL STARTWHEN THE START PUSH BUTTON IS PRESSEDWHEN THE SCANNER DUCT TO FURNACE DIFF.PR. IS LESS THAN 115MM OF WC AND THE OTHER SCANNER AIR FAN IS RUNNINGIF THE OTHER FAN FAILS TO START WITHIN 5 SE. OF ITS START.WHEN SCANNER AIR FAN IS STARTED IMPULSES SHALL BE GIVEN FOROPENING ITS DISCHARGE DAMPERCLOSING THE DISCHARGE DAMPER OF THE OTHER FAN WITH A TIME DELAY OF 5 SEC. PROVIDED THAT FAN IS OFF.

S.VISWANATHAN

INTERLOCKS FOR SCANNER AIR FANS (CONTD.)SCANNER AIR FAN CAN BE TRIPPED BY PRESSING THE STOP PUSH BUTTON PROVIDED THE SCANNER DUCT TO FURNACE P IS MORE THAN 115 MMWCWHEN SCANNER AIR FAN IS TRIPPED, IMPULSE SHALL BE GIVEN TO CLOSE ITS DISCH. DAMEPR PROVIDED THE OTHER FAN IS IN SERVICE WITH A TIME DELAY 5 SEC.

S.VISWANATHAN

INTERLOCKS FOR IGNITOR AIR FANSIGNITOR AIR FAN (SELECTED) CAN BE STARTED BY PRESSING THE PUSH BUTTONIGNITOR AIR FAN (SELECTED) SHALL START AUTOMATICALLY WHEN ANY OIL ELEVATION START IS INITIATEDIGNITOR AIR FAN CAN BE TRIPPED BY PRESSING THE PUSH BUTTON PROVIDED ALL THE IGNITOR VALVES ARE IN CLOSED CONDITION.

S.VISWANATHAN

INTERLOCKS NOT COVERED UNDER BMS/FSSSI.D. FAN INTERLOCKSF.D. FAN INTERLOCKSP.A. FAN INTERLOCKSSEAL AIR FAN INTERLOCKSAIR HEATER INTERLOCKSEMERGENCY BLOWDOWN VALVESSCANNER FAN OUTLET DAMPERSIGNITOR FAN OUTLET DAMPERSINTERLOCKS FOR LUB.OIL SYSTEMS OF FANSFURNACE TEMP. PROBE

S.VISWANATHAN

FAN INTERLOCKS PROVIDEFAN START PERMISSIVESSYSTEM RESPONSE ON STARTING A FANONE IS STARTED OTHER IS NOT IN SERVICEONE IS STARTED OTHER IS IN SERVICEFAN TRIPPING CONDITIONSSYSTEM RESPONSE ON TRIPPING OF A FANONE IS TRIPPED OTHER IS IN SERVICEONE IS TRIPPED OTHER IS NOT IN SERVICE

S.VISWANATHAN

FAN START PERMISSIVESSUCTION AND DISCHARGE DAMPERS ARE CLOSEDFAN CONTROL DEVICE AT MINIMUM POSITIONBEARING TEMP. NOT HIGHLUB. OIL PRESSURE ADEQUATE

FOR F.D. FAN IN ADDITION TO ABOVESELECTED I.D. FAN IS IN SERVICE

S.VISWANATHAN

S.VISWANATHAN

SYSTEM RESPONSE ON STARTING A FAN ONE IS STARTED OTHER IS NOT INSERVICESUCTION AND DISCHARGE DAMPERS OF STARTED FAN OPENS AFTER A TIME DELAY OF 60 SEC.REGULATOR TO FAN CONTROL DEVISE IS CONNECTEDCLOSE THE SUCTION AND DISCHARGE DAMPERS OF OTHER I.D.FAN GIVE PERMISSIVE TO START THE CORRESPONDING F.D.FANOPEN THE INTER CONNECTING DAMPER IF AVAILABLE

S.VISWANATHAN

S.VISWANATHAN

SYSTEM RESPONSE ON STARTING A FANONE IS STARTED OTHER IS INSERVICESUCTION AND DISCHARGE DAMPERS OF STARTED FAN OPENS AFTER A TIME DELAY OF 60 SEC.REGULATOR TO FAN CONTROL DEVISE IS CONNECTEDCLOSE THE INTER CONNECTING DAMPER IF AVAILABLEGIVE PERMISSIVE TO START THE CORRESPONDING F.D.FAN

S.VISWANATHAN

S.VISWANATHAN

FAN TRIPPING CONDITIONSBEARING TEMP. TOO HIGHLUB. OIL PRESSURE TOO LOW

INADDITION TO ABOVEFOR I.D. FANCORRESPONDING AIR HEATER TRIPS

FOR F.D. FANCORRESPONDING I.D.FAN TRIPS

FOR P.A. FANCORRESPONDING F.D.FAN TRIPSBOILER TRIPS

S.VISWANATHAN

SYSTEM RESPONSE ON TRIPPING A FANONE IS TRIPPED OTHER IS INSERVICESUCTION AND DISCHARGE DAMPERS OF TRIPPED FAN CLOSES IMMEDIATELYFAN COTROL DEVISE IS BROUGHT TO MINIMUM AND REGULATOR TO FAN CONTROL DEVISE IS DISCONNECTED OPEN THE INTER CONNECTING DAMPER IF AVAILABLETRIP THE CORRESPONDING F.D.FANENERGISE PART LOAD RELAY

S.VISWANATHAN

SYSTEM RESPONSE ON TRIPPING A FANONE IS TRIPPED OTHER IS NOT INSERVICESUCTION AND DISCHARGE DAMPERS OF TRIPPED FAN REMAINS OPENFAN COTROL DEVISE IS BROUGHT TO MAXIMUMTRIP THE CORRESPONDING F.D.FANOPEN THE SUCTION&DISCHARGE DAMPERS ANDFAN REGULATING DEVISE OF OTHER FANOPEN ALL DAMPERS IN F.G.PATH

S.VISWANATHAN

INTERLOCKS FOR SEAL AIR FANSSEAL AIR FAN IS IS PROHIBITED FROM STARTING UNLESS ONE OF THE P.A. FAN IS RUNNING A RUNNING SEAL AIR FAN CAN BE TRIPPED ONLY IF ALL THE MILLS ARE TRIPPED OR OTHER SEAL AIR FAN IS RUNNINGSEAL AIR FAN WILL BE TRIPPED AUTOMATICALLY WITH ATIME DELAY OF 60 SEC. IF BOTH P.A. FANS TRIP

S.VISWANATHAN

AIR HEATER INTERLOCKSAIR HEATER ELECTRIC MOTOR/AIR MOTOR WILL TRIP WHEN THE SUPPORT/GUIDE BEARING TEMP.IS VERY HIGHWHENEVER AIRHEATER ELECTIC MOTOR TRIPS IMPULSE SHALL BE GIVEN FORSTARTING AIR HEATER AIR MOTOR PROVIDED THE SUPPORT AND GUIDE BEARINGS TEMP. IS LESS THAN 700C

S.VISWANATHAN

S.VISWANATHAN

AIR HEATER INTERLOCKSWHENEVER BOTH ELECTIC MOTOR AND AIR MOTOR TRIP IMPULSE SHALL BE GIVEN FORCLOSING INLET AND OUTLET DAMPERS IN FLUE GAS, SY.AIR, P.A. LINES TO AIR HEATERTRIPPING OF CORRESPONDING I.D.FAN IF OTHER I.D. AND A.H. ARE IN SERVICETRIP BOTH I.D. FANS IF OTHER A.H. IS NOT IN SERVICEOPEN INTER CONNECTING DAMPER IN HOT S.A.LINE IF OTHER A.H. IS IN SERVICE

S.VISWANATHAN

INTERLOCKS FOR EBD VALVETHIS VALVE WILL OPEN WHEN THE DRUM LEVEL REACHES VERY HIGH LIMITTHIS VALVE WILL CLOSE ONLY WHEN THE DRUM LEVEL REACHES NORMAL LEVEL

DRUMEBD LINEIBD EXPANDER

S.VISWANATHAN

FURNACE TEMP. PROBETHE PROBE IS PROHIBITED FROM ADVANCING INTO THE FURNACE IF THE FURNACE OUTLET TEMP.IS MORE THAN 5400CIF THE PROBE IS INSIDE THE FURNACE AND IF THE FOT INCREASES ABOVE 5400C THE PROBE RETRACTS AUTOMATICALLY

S.VISWANATHAN