DISTURBANCE IN BOILER DRUM WATER LEVEL-IF THERE IS SUDDEN LOAD THROW OFF THE WATER LEVEL WILL GO DOWN AND PRESSURE WILL RISE.HENCE WHENEVER THERE IS POSSIBILITY OF LOAD DROP,OPERATOR SHOULD BE CAREFUL TO CONTROL WATER LEVEL.DUE TO SUDDEN LOAD PICK UP WATER LEVEL WOULD RISE,IF TOOMUCH COLD WATER IS FED TO THE BOILER WATER WULD RISE.IF THERE IS ANY DOUBT ABOUT WATERLEVEL THEN CHECK THE WATER LEVEL AT DRUM GAUGE GLASS.IF NONE OF YHE GAUGE GLASSES ARE IN SERVICE IT IS PREFERABLE TO WITHDRAW BOILER FROM SERVICE.IF WATER LEVEL VASHES OUT OF SIGHT AND FEED FLOW IS NOT AVAILABLE FOR CONSIDERABLE TIME IT IS PREFERABLE NOT TO FILL IN WATER UNTIL THE BOILER HAS COOLED DOWN NATURALLY.THIS IS TO AVOID QUENCHING OF HOT METAL PARTS.
POSSIBLE CAUSES OF WATER LEVEL DROPPING IS FEED PUMP FAILURE, FEED WATER PRESSURE REGULATING VALVE MALFUNCTION, ECONOMISER LEAKAGE, BOILER OR WATER WALL TUBE FAILURE, EXTRAORDINARY CHANGE IN LOAD.
ABNORMALLY HIGH WATER LEVEL SHOULD BE AVOIDED AS IT MAY LEAD TO CARRY OVER AND EVEN PRIMING.USE EMERGENCY BLOWDOWN VALVE TO REDUCE LEVEL.
CARRY OVER-IF CARRY OVER OCCURS,AS INDICATED BY LOWER THAN NORMAL STEAM TEMPERATURE OR SUDDEN DROP IN STEAM TEMPERATURE THEN LOWER DRUM LEVEL,CHECK BOILER CONCENTRATION,IF IT IS HIGH REDUCE THE SAME BY BLOWING DOWN THROUGH CBD,INVESTIGATE DRUM INTERNALS ON THE EARLIEST OPPORTUNITY.
No comments:
Post a Comment