SEAL OIL SYSTEMIN ORDER TO PREVENT ESCAPE OF

HYDROGEN FROM THE GENERATOR IT IS ESSENTIAL TO PROVIDE SHAFT SEALS AT BOTH ENDS WHERE THE SHAFT EXTENDS THROUGH THE CASING.

THIS IS ACHIEVED BY PROVIDING RADIAL OIL FILMS IN THE SYSTEM, THIS OIL BEING KEPT AT A HIGHER PRESSURE THAN THAT OF THE HYDROGEN INSIDE THE GENERATOR.THE LOCATION WHERE THE ROTOR SHAFT PASSES THROUGH THE STATOR CASING ARE PROVIDED WITH

RADIAL OR RING TYPE SEAL RINGS.THE SEAL EING IS FORMED BY JOINING TWO SEMICIRCULAR RINGS.

BABBIT METAL• BABBIT METAL IS A COMPOSITION OF TIN, ANTIMONY AND

COPPER .THE SEAL RING IS LINED WITH BABBIT METAL ON THE SHAFT JOURNAL SIDE.

• BABBIT METAL HAS A LOW MELTING TEMPERATURE TO SAFEGUARD THE SHAFT IN CASE OF OIL STARVATION.

• THE SEAL OIL IS SUPPLIED TO THE SEALING GAP FROM THE SEAL BODY VIA RADIAL HOLES AND ANNULAR GROOVE IN THE SEAL RING.

• THE TWO HALF OF THE SEAL RING ARE GUIDED IN THE SEAL BODY, WHICH IS BOLTED ON THE END SHIELD

SEALING PHENOMENON

• TO ENSURE EFFECTIVE SEALING THE SEAL OIL PRESSURE IN THE ANNULAR GAP IS MAINTAINED AT 1.5 KSC ABOVE THE GAS PRESSURE WITHIN THE GENERATOR CASING.

 

• THE OIL DRAINED ON THE HYDROGEN SIDE AND AIR SIDE OF THE SEALRINGS IS THROUGH DRAINS IN THE SEAL BODY AND SEALING COVER RESPECTIVELY.

 

• ON THE AIR SIDE RING RELIEF OIL IS SUPPLIED AT 0.5KSC ABOVE THE SEAL OIL PRESSURE LATERALLY TO THE SEAL RING VIA AN ANNULAR GROOVE.

Seal oil system scheme

EQUIPMENTS IN SEAL OIL SYSTEM

• SEAL OIL PUMP ( 3 X 100%) DUTY

• VACUUM PUMP (1)

• SEAL OIL COOLER ( 2 X 100%) DUTY

• DIFFERENTIAL PRESSURE REGULATOR

• SEAL OIL FILTERS (DUPLEX & SIMPLEX)

SEAL OIL PUMP

– SEAL OIL PUMP IS A THREE SCREW DESIGN POSITIVE DISPLACEMENT PUMP

– ONE DOUBLE THREADED DRIVING ROTOR AND TWO DRIVEN IDLER SCREWS ARE CLOSED MESHED AND RUN WITH A CLOSE CLEARANCE IN THE CASING INSERT.

– BY INTERMESHING, THE HELICAL PASSAGES IN THE ROTORS ARE DIVIDED INTO COMPLETELY SEALED COMPARTMENTS, WHILE ROTATING, TRAVEL UNIFORMLY AND WITH OUT UNDUE STRESSES FROM SUCTION TO DISCHARGE END.

– THIS ACTS LIKE A PISTON – DUE TO LOW COMPRESSIBILITY OF OIL VERY HIGH PRESSURE MAY

ARISE ON THE DELIVERY SIDE– HENCE RELIEF VALVE IS PROVIDED ON THE PUMP CASING TO

PROTECT THE SEAL OIL SYSTEM

VACUUM PUMP

– THE VACUUM PUMP IS A SINGLE STAGE ROTARY VANE TYPE

– ROTARY SLIDING VANE PUMP CONSISTS OF A CYLINDRICAL CASING

WHICH IS ECCENTRICALLY SUPPORTED

– THE ROTOR HAS VANES WHICH ARE FORCED APART BY SPRINGS

– THE VANES SLIDE ALONG THE CASING WALL.

– IT PUSHING FORWARD THE AIR DRAWN IN AT THE SUCTION

CHANNEL AND FINALLY DISCHARGING IT AT THE PUMP THROUGH

THE OIL IMMERSED DISCHARGE VALVE

– THE OIL ALSO SERVES AS THE PUMP LUBRICATION

– OIL LEVEL IN THE PUMP HAS TO ENSURED AS OIL VAPOUR GETS

EXTRACTED WHEN EXPELLING THE GAS.

SEAL OIL COOLER• THIS COOLER IS DESIGNED FOR SERVICE WITH RAW WATER.

COOLER CONSISTS OF

I. UPPER WATER BOX

II. SHELL

III. TUBE SYSTEM

IV. LOWER WATER BOX

THE LOWER TUBE PLATE IS FIXED AND THE UPPER TUBE

PLATE IS MADE FLOATING TO CATER FOR THE THERMAL

DIFFERENTIAL EXPANSION BY USING A RUBBER RING.

OIL INLET AND OUTLET ARE PROVIDED IN THE SHELL.

THE CIRCULATING WATER SIDE OF THE TUBE PLATE AND THE

INNER SURFACE OF THE WATER BOX ARE PAINTED WITH EPOXY

COAL TAR

SEAL OIL COOLER MAINTENANCE

• THE EFFICIENCY OF THE COOLER DEPENDS VERY MUCH ON THE

CLEANLINESS OF THE COOLING SURFACE

• CLEANING OF THE INSIDE OF THE TUBES CAN BE CARRIED OUT BY MEANS

OF SOFT BRASS WIRE BRUSH MECHANICALLY.

• IF THERE ARE HARD SCALES CHEMICAL TREATMENT HAS TO BE RESORTED

• LIKE WISE SHELL SIDE CAN BE CLEANED.

• SHELL CAN BE CLEANED IN A HOT BATH OF 10% CAUSTIC SODA SOLUTION

• IN CASE OF LEAKAGE OF COOLER TUBE IS SUSPECTED THE SHELL SIDE

SHOULD BE SUBJECTED TO A PRESSURE OF 16 KSC USING LUBE OIL.

KEEPING THE COOLER IN THE HORIZONTAL POSITION AND THE FAULTY

TUBE SHOULD BE PLUGGED WITH TAPER PLUGS. 5 % OF THE TUBES CAN

BE PLUGGED WITH OUT SACRIFICING THE DUTY.

DIFFERENTIAL PRESSURE REGULATING VALVE

• DIFFERENTIAL PRESSURE REGULATING VALVE IS INTENDED TO REGULATE THE SEAL OIL PRESSURE BEING SUPPLIED TO SHAFT SEALS IN RELATION TO GAS PRESSURE IN THE GENERATOR CASING.

• DIFFERENTIAL PRESSURE REGULATOR HAS 1. VALVE HEAD2. MAIN BELLOWS3. UPPER STUFFING BELLOWS4. VALVE STEM

5. COMPRESSION SPRING6. ADJUSTING NUT7. CHECK NUT8. YOKE9. LOWER STUFFING BELLOWS10. VALVE HOUSING11. VALVE CONE

• SEAL OIL TANK

GAS IMPULSE

OIL IMPULSE

O

I

L

S

E

A

L

S

SEAL OIL PUMP

DIFFERENTIAL PRESSURE REGULATOR AFUNCTION

DIFFERENTIAL PRESSURE REGULATOR FUNCTION

• THE DIFFERENCE BETWEEN OIL AND GAS IS SET BY COMPRESSION OF THE

SPRING WITH HELP OF THE ADJUSTING NUT.

• COMPRESSION OF THE SPRING LEADS TO DOWN MOVEMENT OF THE VALVE

STEM AND VALVE CONE.

• THIS MOVEMENT REDUCES THE PRESSURE THROUGH THE VALVE AS THE

VALVE CLOSES AND INCREASES THE PRESSURE THROUGH THE LINE.

• INCREASE IN H2 PRESSURE WILL LEAD TO COMPRESSION OF THE MAIN

OPERATING BELLOW WHICH IN TURN WILL MOVE THE VALVE HEAD IN TURN

VALVE AND VALVE CONE TO CLOSE THE VALVE

• CLOSING OF THE VALVE WILL REDUCE THE PRESSURE OF THE OIL AT THE

OUT LET OF THE VALVE WHILE OIL PRESSURE GOING TO THE SEALS WILL

INCREASE.

DIFFERENTIAL PRESSURE REGULATOR B FUNCTION

GAS IMPULSE

OIL IMPULSE

OIL SEALSFROM GOVERNING OIL

SEAL OIL FILTER

• THE DUPLEX AND SIMPLEX FILTERS ARE USED IN SINGLE FLOW RING TYPE

SEAL OIL SYSTEM

• THE FILTER IS INSERTED INTO THE PIPE CIRCUIT BY MEANS OF FLANGES

• A CHECK IS KEPT ON THE STRAINER SCREEN BY MEANS OF THE

RECOMMENDED DIFFERENTIAL PRESSURE INDICATOR .

• WHEN PRESSURE REACHES 0.6 KSC THE STRAINER SHOULD BE CLEANED.

• THE COMMON PROBLEM IS THE “O” RING FAILURE IN THE STOP COCK.

SEAL OIL FILTER -I• IF THERE IS LEAK FROM THE STOP COCK

• REMOVE THE PINS

• PULL OUT THE STOP COCK

• REMOVE THE “O “ RING

• WASH OUT THE STOP COCK AND HOUSING

• INTRODUCE THE STOP COCK AFTER GOOD OILING BUT WITHOUT O RINGS INTO

THE OPENING IN THE HOUSING

• PUSH THE STOP COCK UNTIL THE GROOVE FOR THE “ O “ RING IS FREE

• FIT THE “ O” RING AND CAREFULLY PULL BACK THE STOP COCK UNTIL THE

GROOVE AT THE OPPOSITE END IS FREE.• CLEANING OF FILTER CHAMBER IS NECESSARY ONLY AFTER EVERY THIRD

FILTER ELEMENT CLEANING

STATOR WATER SYSTEM

• ONE OF THE EFFICIENT WAYS OF TAKING AWAY THE LOSSES FROM THE WINDINGS OF ANY ELECTRICAL MACHINE IS BY DIRECT COOLING USING WATER.

EQUIPMENTS INVOLVED IN THE STATOR WATER SYSTEM

• EXPANSION TANK

• STATOR WATER PUMP

• STATOR WATER COOLERS

• STATOR WATER MECHANICAL FILTERS

• STATOR WATER MAGNETIC FILTERS

• POLISHING UNIT

• GAS TRAP

STATOR WATER SYSTEM HEADERS

INLET HEADER

OUTLET HEADER

STATOR WATER TO BUSHING LEADS

QUALITY OF THE DISTILLATE• CONDUCTIVITY < 5 MICRO MHO, PREFERABLY < 1 MICRO MHO• PH 6.5 TO 8.5• DISSOLVED OXYGEN MINIMUM, PREFERABLY LESS THAN 100 PPB• DISSOLVED CO2 NIL• AMMONIA MINIMUM, PREFERABLY ZERO• CHLORIDE MINIMUM, PREFERABLY ZERO• DISSOLVED/UNDISSOLVED CU < 20 PPB• DISSOLVED/UNDISSOLVED FU < 20 PPB• DISSOLVED SOLIDS THE WATER SHOULD BE FREE OF ANY CHEMICALS

FROM TREATMENT PROCESS,SUCH AS HYDRAZINE,MORPHOLINE,LEVOXINE,PHOSPHATES

THE EXPANSION TANK • THE EXPANSION TANK IS A HERMETICALLY SEALED CONTAINER MADE

OF STAINLESS STEEL.

• THE DM WATER FROM THE STATOR WINDING OUTLET HEADER

DISCHARGES IN TO A SECTION OF THE TANK THROUGH PERFORATED

PIPE.

• THE TANK IS UNDER A VACUUM OF 250-300MM OF MERCURY.

• THE TANK IS CLEANED DURING ANNUAL MAINTENANCE.

• THE FLOAT VALVE OPERATION IS CHECKED BY HAND FOR SMOOTH

AND EASY OPERATION FROM ONE EXTREME LOWER POSITION TO

EXTREME TOP POSITION.

• THE FLOAT IS CHECKED BY DIPPING IN WATER FOR 1 HOUR AT A

TEMPERATURE OF 60 DEGREE CENTIGRADE

• THE HEALTHINESS OF THE TRANSDUCERS ARE CHECKED.

• ALL THE JOINTS ARE CHECKED FOR ANY LEAK.

EXPANSION TANK

GAS OUT LETWATER INLET FROM WINDING

TANK

COVER

TRANSDUCER

RIB

LEVEL

GAUGE

DRA

I

N

WATER OUTLET TO PUMPS

LINE REGULATOR

STATOR WATER PUMP

• STATOR WATER PUMPS ARE SINGLE STAGE CENTRIFUGAL TYPE SPIRAL CASING AND OVERHANG IMPELLER .

• THE PUMP SUCTION IS ARRANGED IN THE AXIAL DIRECTION WHILE THE DISCHARGE IS DIRECTLY RADIALLY UPWARD.

• THE PUMP IMPELLER AND THE SPIRAL CASING IS OF STAINLESS STEEL CONSTRUCTION.

• NORMALLY THE PUMP IS OVERHAULED ONCE IN 5000 HOURS.

STATOR WATER COOLERSTATOR WATER COOLER

UPPER WATER BOX

TUBE PLATE

SEALING CORD

VENT PLUG

PARTITION TUBE

OUTER SHELLSEALING RUBBER

DRAIN PLUGTHERMOMETER

STATOR WATER INLET

STATOR WATER OUTLET

VENT

DRAIN PLUG

LOWER WATER BOX

RUBBER CORD

STATOR WATER COOLER-I

• THE STATOR WATER COOLER IS SHELL AND TUBE TYPE HEAT

EXCHANGER SUITABLE FOR VERTICAL MOUNTING

• THE SHELL IS MADE OF NONMAGNETIC STAINLESS STEEL AND THE DM

WATER FLOWS THROUGH THE SHELL.

• TUBES ARE MADE OF STAINLESS STEEL AND THE COOLING WATER

FLOWS THROUGH THE TUBES.

• TO HAVE EFFECTIVE HEAT TRANSFER BAFFLES ARE MADE OF BRASS

ARE PROVIDED ACROSS THE TUBE NEST.

• THIS GUIDE THE WATER IN ZIG ZAG FASHION.

• THE TUBES ARE CLEANED BY NYLON BRUSH.

STATOR WATER COOLER -II

• WHEN PUSHING THE BRUSH THROUGH THE TUBES IT SHOULD ALSO BE

TURNED AROUND SIMULTANEOUSLY

• IF THE DIRT DEPOSITS DO NOT COME WITH MECHANICAL TREATMENT

CHEMICAL CLEANING IS NECESSARY.

• THE MOST CAUSE OF LEAKAGE IS TUBE PERFORATION OR LEAKAGE.

• THE ROLLED ENDS OF THE TUBE ARE LIKELY TO BECOME DEFECTIVE FIRST.

• REROLL THE AFFECTED TUBE WITH TUBE EXPANDER.

• IF NOT PLUG THE TUBE IF IT IS URGENT .

• UPTO 5% OF THE COOLING TUBE CAN BE PLUGGED WITH OUT AFFECTING THE

DUTY

POLISHING UNIT-I• POLISHING UNIT SERVES TO MAINTAIN LOW ELECTRICAL CONDUCTIVITY

OF THE CONDUCTIVITY OF THE PRIMARY WATER.• POLISHING UNIT IS CONNECTED IN PARALLEL TO THE MAIN CIRCUIT• POLISHING UNIT CONTAINS

1. MIXED BED ION EXCHANGER

2. FILTER

3. FLOW METER

4. CONDUCTIVITY METER

THE BASE SUBSTANCES OF THE EXCHANGER ARE POLYMERS.

THE POLYMERS IN THE CATION EXCHANGER ARE HIGHLY ACIDIC GROUPS

THE POLYMERS IN THE ANION EXCHANGER ARE HIGHLYBASIC GROUP.

WHEN RESINS ARE EXHAUSTED THEY THEY MUST BE REPLACED.

POLISHING UNIT –TECHNICAL DATA

CAPACITY 2 M3

DESIGN CONDUCTIVITY AT THE IN LET 1 MICRO MHO/CM

CONDUCTIVITY OF THE WATER AT OUT LET 0.44 MICRO MHO/CM

PH VALUE OF THE WATER AT THE INLET 6 TO 7 MICRO MHO/CM

PH VALUE OF THE WATER AT THE OUTLET 7±0.2

OPERATING RESIN BED 6 MONTHS

FINAL FILTER SIZE 5 MICRONS

RESIN TULSION T –42

TULSION A-27 MP

REAGENT HCL – 30% 20.3KG

NAOH –100% 11.5

KG

MAGNETIC FILTER-PRINCIPLE

• THE MAGNETIC FILTER IS OF PERMANENT MAGNET TYPE

DESIGNED TO TRAP FERRO MAGNETIC PARTICLES

• THE FILTER MAINLY CONSISTS OF AN UPPER AND A LOWER

BODY HOUSING THE PERMANENT MAGNET SYSTEM,

COMPRISING OF THE MAGNETS POLE SHOES AND POLE RINGS

• THE DM WATER PASSES THROUGH TWO ANNULAR AIR GAPS IN

WHICH THE FERRO MAGNETIC PARTICLES ARE FILTERED OUT.

MAGNETIC FILTER MAINTENACE

• THE UPPER BODY IS REMOVED

• WITH HELP OF THE REMOVABLE BOLTS THE POLE RING IS

DISMANTLED .

• THE POLE RING AND THE POLE SHOES ARE CLEANED AND THE

ENTRAPPED FERRO MAGNETIC PARTICLES ARE THOROUGHLY WIPED

• THE FILTER IS ASSEMBLED AND INSTALLED BACK IN POSITION AND O

RING IS REPLACED , IF IT IS IN DAMAGED CONDITION

MAGNETIC FILTER

MAGNETIC FILTER TECHNICAL DATA

MAGNET TYPE PERMANENT MAGNET

THE CAPACITY OF THE MAGNETIC FILTER 36M3

MAXIMUM INDUCTION DENSITY 4000GAUSS

PRESSURE RATING NOT MORE THAN 10 KSC

TYPE OF PARTICLES FILTERED HIGHLY AND

MEDIUM

MAGNETIC

HYDRAULIC TEST PRESSURE 16KSC FOR 10 MINUTE

PRESSURE DROP NEGLIGIBLE

STATOR WATER MECHANICAL FILTER• THE FILTER BODY CONSISTS OF CYLINDRICAL BODY HAVING SEPARATE

INLET AND OUT LET CHAMBERS.• A PERFORATED CYLINDRICAL BODY HAVING HOLES ALL ALONG ITS

LENGTH AND PERIPHERY IS SURROUNDED BY THE ASSEMBLY OF 30 TO 34 FILTER ELEMENTS.

• THE FILTER ELEMENTS ARE KEPT IN POSITION BY A HELICAL SPRING WHICH IS KEPT PRESSED BY A COVER.

• THE FILTER ELEMENTS CONSISTS OF CORRUGATED BRASS SHEET WITH A CENTRE HOLE AND TWO SIZES OF WIRE MESH APERTURES 0.224 MM AND 0.5 MM HELD IN ONE ASSEMBLY BY INNER AND OUTER BRASS RING.

• THE WATER AFTER PASSING THROUGH THE FILTERING ELEMENTS ENTERS THE PERFORATED CYLINDER FROM WHERE IT FLOWS TO THE OUTLET CHAMBER.

• IMPURITIES GET COLLECTED IN THE WIRE MESH.• THE FILTER IS PROVIDED WITH DRAIN AND VENT PLUGS.

STATOR WATER MECHANICAL FILTERTECHNICAL DATA

TYPE WIRE MESH TYPERATED DISCHARGE 30 M3

MAXIMUM PRESSURE RATING 12 KSC

MINIMUM SIZE OF THE PARTICLES 0.224

THAT CAN BE FILTERED

PRESSURE DROP 0.1 KSC TO 0.2 KSC

PRESSURE DROP –WHEN CLEANING IS

RECOMMENDED 0.4 KSC

MATERIAL OF THE BODY AND

PERFORATED CYLINDER Stainless steel

MATERIAL OF THE FILTER ELEMENT BRASS

SIZE OF THE WIRE MESH 0.224 MM AND 0.5 MM

HYDRAULIC TEST PRESSURE 38 KSC FOR 15 MINUTES

GAS TRAP

• GAS TRAP IS USED FOR DETECTING THE PRESENCE OF HYDROGEN

GAS IN THE STATOR WATER SYSTEM. • PRESENCE OF THE GAS IN THE WATER SYSTEM IS POSSIBLE DUE TO

LOOSE AND LEAK AS JOINTS AS THE WATER PRESSURE IS KEPT LOWER

THAN THE HYDROGEN PRESSURE IN THE GENERATOR CASING.• THE GAS ENTRAPPED IN THE WATER GOES TO THE UPPER CHAMBER

FROM WHERE THE GAS IS SAMPLED FOR ANY MIXING.• TOP POINTS OF THE SUPPLY AND DRAINAGE ARE CONNECTED TO ANY

INLET POINTS OF THE DEVICE.• THE THIRD POINT IS CONNECTED TO PIPE LINE AT THE OUTLET OF THE

GENERATOR.

GAS TRAP -I

• DRAIN PIPE IS CONNECTED TO THE DRAINAGE SYSTEM.• THREE POINTS OF THE INLET ARE CRACK OPENED AND THE WATER IS

ALLOWED TO ENTER CONTINUOUSLY.

• THE WATER SO ENTERED WILL BE CONFINED TO LOWER CHAMBER OF

THE DEVICE AND THE EXCESS WATER IS DRAINED TO THE DRAIN PIPE .

• IN CASE OF WATER CARRYING HYDROGEN,THE SAME IS LIBERATED AT

THE TOP CHAMBER

• THE GAS ENTERS THE SPACE THROUGH THE CENTRE HOLE IN THE

PLUG AND IS DIRECTED TO THE UPPER CHAMBER THROUGH THE SLOT

IN THE PLUG.

GAS SYSTEM-IGAS REQUIREMENT 56M3

AMOUNT OF HYDROGEN REQUIRED TO FILL THE GENERATOR 300M3

CASING TO RATED PRESSURE AT NTP-M/C STATIONARY

AMOUNT OF HYDROGEN REQUIRED TO FILL THE GENERATOR

CASING TO RATED PRESSURE AT NTP-M/C STATIONARY 340M3

MAKE UP OF HYDROGEN REQUIRED /DAY 15M3

AMOUNT OF CO2 REQUIRED TO REMOVE HYDROGEN AT NTP 120M3

WHEN MACHINE IS RUNNING 168M3

AMOUNT OF CO2 REQUIRED TO REMOVE AIR AT NTP 90M3

WHEN MACHINE IS RUNNING 112M3

EACH H2 CYLINDER IS OF CAPACITY 46.7 LITRES AND CONTAINING APPROXIMATELY 7 M3 AT 150 ATMNO. OF H2 CYLINDERS REQUIRED TO FILL THE MACHINE

WHEN STATIONARY 50WHEN RUNNING 56

NO. OF CYLINDERS REQUIRED/DAY 2 TO 3

EACH CO2 CYLINDER IS 30 KGS WEIGHT OF CO2 WITH GAS EQUIVALENT TO 15M3 OF GAS VOLUME.NO. OF CYLINDERS REQUIRED FOR PURGING HYDROGEN

WHEN STATIONARY 11RUNNING 14

NO. OF CO2 REQUIRED FOR PURGING AIR WHEN STATIONARY 8NO. OF CO2 REQUIRED FOR PURGING AIR WHEN RUNNING 10

GAS SYSTEM-II

GAS DRIER

THANK YOU