The document discusses the components and operation of condensate extraction pumps, boiler feed pumps, and turbine driven boiler feed pumps. It describes how condensate extraction pumps extract condensate from the condenser hotwell and pump it to the deaerator. It outlines the multi-stage design and sealing of boiler feed pumps used to pressurize feedwater before entering the boiler. It also provides details on the oil, feedwater, gland seal steam, and extraction steam systems involved in starting up a turbine driven boiler feed pump.

1. WHY CONDENSER

2. What is condensate
 The steam after condensing
in the condenser known as
condensate, is extracted out
of the condenser hot well by
condensate pump and taken
to the deaerator through
ejectors, gland steam cooler
and series of LP heaters.

3. Condensate system
• Condensate Extraction Pump :
To pump out the condensate to D/A through
ejectors, GSC and LPH
• Gland Steam Condenser :
To increase the temperature of condensate.
• Condensate polishing unit :
To remove cat-ion and an-ion from the
condensate.

4. CEP
• Converts last stage steam of LPT to water
CEP
CONDENSER DEAREATO
GSC CPU
R LEVEL
CONTROL
CONDENSER
Minimum recirculation to condenser

5. Condensate Pumps
 The function of these pumps is
to pumps out the condensate to
the deaerator thru' ejectors,
gland steam cooler, and L.P.
heaters. These pumps have
FIVE stages and since the
suction is at a negative
pressure, special arrangements
have been made for providing
sealing.

6. Stages:
The pressure build up in 5 stages
as suction is at negative pressure.
Recirculation:
It is done when the de aerator level
controller trips in order to prevent
cavitations.

9. CEP LINE UP
 Ensure PTW cancelled
 Ensure box up
 Suction strainer drain/vent close
 Open canister vent
 Open re-circulation manual v/v
 c/v inst. Air v/v
 Seal water charge
 Bearing cooling water charge
 Bearing oil level normal
 Relief v/v manual v/v open
 Suction v/v open
 Relies EPB

10.  Supply normal
 Hotwell level N low ( > - 250mm)
 SWGR available
 SWGR not disturbed
 Thrust brg temp not high
 Motor brg. Temp not high
 Motor wdg temp not high
 R/c v/v open > 40 %
 Discharge vent open
 Discharge v/v close or stand by selected

11. CEP ISOLATION
 EPB pressed
 Breaker rack out
 Is R/c v/v passing
 Close suction v/v
 By pass relief v/v close
 Close re-circulation v/v
 Close canister vent v/v
 Discharge vent manual v/v close
 Close sealing water v/v
 Close cooling water v/v
 Crack open strainer vent. Is there any air
sucking?

12. Boiler Feed Pump
 To give the required pressure to
the feed water before entering
into boiler
 Horizontal barrel type multi
stage pump.

13. BOILER FEED
PUMP
NDE BEARING DE BEARING
SLEEVE
KEY
FOUNDATION BOLT
SOLE PLATE
(BASE PLATE)
18

14. General Arrangement of BFP
To HPH. Recirculation to FST
Feed Water
From D/A
Suction
Strainer
Main
Motor
Pump
Booster
Pump
S S for
Hydraulic
Main Pump
Coupling

15. Components of BFP
Booster Pump
To Ensure a Net Positive Suction Head (NPSH) for
Main Feed Pump
Saves a Costly Main Pump due to any damage from
Cavitation.
Typically a single-stage, centrifugal pump
Recirculation :
To maintain the Continuous flow of feed water when
the valve to Economizer is Closed

16. Components of BFP
Suction Strainers
To Protect Booster pump and main pump against
Catastrophic failure due to entry of coarse
particles
Hydraulic Coupling
Used to Transmit power from motor to pump as
per the
Load requirement

17. NPSH
NPSH is an acronym for Net Positive Suction Head . It
shows the difference, in any cross section of a generic
hydraulic circuit, between the pressure and the liquid vapor
pressure in that section.
NPSH is an important parameter, to be taken into account
when designing a circuit : whenever the liquid pressure drops
below the vapor pressure, liquid boiling occurs, and the final
effect will be cavitations : vapor bubbles may reduce or stop
liquid flow.
In pump operation, two aspects of this parameter are called
respectively NPSH (a) Net Positive Suction Head (available)
and NPSH (r) Net Positive Suction Head (required), where
NPSH(a) is computed at pump inlet port, and NPSH(r) is the
limit NPSH the pump can withstand without cavitating.

18. Booster Pump
 Major damage in BF pump is
from cavitation or vapour
bounding.
 Provides positive pressure at
the pump suction.

19. BFP CARTRIDGE

20. BFP WITH COMMON FOUNDATION FRAME

21. BFP SEAL COOLER PIPING

22. MECHANICAL SEAL
• The use of mechanical seal reduces the loses of feed water
in the stuffing box to a minimum.
• Working ability of the feed pump increases.
• Cooling of stuffing box space should be perfect by the use
of mechanical seal.
• Cooling is carried out by the circulation of water between the
stuffing box space and the cooler. Even after stopping the
pump stuffing box cooling should be continued as its cooling
circuit is different from the seal cooler.
• Coolers are designed to keep the stuffing box space
temperature below 800C.

23. MECHANICAL SEAL
It consists of two highly polished surfaces, one surface connected to
the Shaft and the other to the stationary part of the Pump.
• Both the surfaces are of dissimilar materials held in continuous
contact by a spring.
• These wearing surfaces are perpendicular to the axis of Shaft.
• A thin film of working fluid between these faces provides cooling &
lubrication.

24. SEAL HOUSING
It houses the Mechanical Seal.

25. Line Bearings
• They give radial positioning to the rotor.
• They are of two types :
• Antifriction Bearings
• Sleeve Bearings

26. Thrust Bearings
They locate the rotor axially & take residual axial
thrust.
• They are fitted in the NDE Bearing Housing.
• They have 8 white metal lined tilting pads held in a
split Carrier Ring positioned on each side of the
Thrust Collar.

27. BEARING HOUSINGS
• They house Journal Bearing at the DE side and both
Journal & Thrust Bearings at the NDE side.
• These are in the form of cylindrical castings split on
the horizontal Shaft axis, located one each at DE &
NDE sides of the Pump.

28. PUMP CASING
It houses the hydraulic components of Pumps.
• It prevents the leakage and guides the liquid in a
proper direction.
• It is closed by Suction Guide at it’s suction side and
Discharge Cover at it’s discharge side.

29. SUCTION
GUIDE
• It guides the fluid from suction pipe to the eye of the
Impeller.
• It closes the drive end of Pump Casing and forms
the suction annulus.

30. DISCHARGE COVER
It closes the NDE of Pump Casing and forms the
balance chamber.
• It is closed by NDE Water Jacket and Mechanical
Seal Housing.
• A Spring Disc is located between the last stage
Diffuser and the Discharge Cover Balance Drum
Bush.

31. IMPELLER
It rotates the mass of fluid with the peripheral speed of
its vane tips, thereby determining the head
developed or the Pump working pressure.

32. IMPELLER

33. DIFFUSE
R
• It converts Kinetic energy of the fluid into Pressure
Energy.

34. ROTATING ASSEMBLY
• It consists of Shaft, Impellers, Balance Drum, Thrust
Collar, rotating parts of Mechanical Seals and the Pump
Half Coupling.
• It is dynamically balanced.

35. Balancing Device
• A small portion of the feed water in the order of about 10% which is
not calculated to the guaranteed delivery capacity is taken off from
the space behind the last impeller for the operation of the
automatic balancing device to balance the hydraulic axial thrust of
the pump rotor.
• The purpose of the balancing device is to take up thrust pressure
in a similar way as the thrust bearing.
BALANCE DRUM

36. BALANCE DRUM
 The Balancing Chamber is connected either to
the Pump suction or to the Deaerator, thus the
back pressure in Balancing Chamber is
slightly higher than the suction pressure.
 95% of axial thrust is balanced by the
Balancing Drum.
 Residual axial thrust is taken by Thrust
Bearing.
 Provision of Thrust Bearing is recommended
for varying condition of Head and Flow which
affect the axial thrust.

41. MDBFP LINE UP
 OIL SIDE
1. HC oil level normal
2. Cooler line up
3. Start AOP
4. Lube oil WO pr. Ok
5. Bearing oil flow normal
6. No oil leakage

42.  Suction v/v open fully
 R/c v/v manual v/v open
 R/c v/v c/v inst. Air v/v open*
 Motor wdg cooling water supply/ return line v/v open
 Cooling water header pressure ok
 Main p/p and booster pump mechanical seal water /
cooling water charge
 Venting done*
 EPB released
 Discharge v/v close and IBV close
 Header drain /recirculation/casing drain close *

43. TDBFP LINE UP
 OIL SIDE
 FEED WATER SIDE
 GLAND SEAL STEAM/ VACUUM
SIDE
 EXTRACTION STEAM SIDE
 BARRING SIDE

44. TDBFP LINE UP
 PTW CANCELLED
 BOXED UP
 OIL SIDE
1. LOT level normal
2. Cooler line up from oil /water side
3. AOP/EOP/JOP suction/discharge v/v open
4. Governing oil manual v/v open
5. All lops supply normal
6. Start EOP and check oil lkg.
7. Start JOP and check oil lkg
8. Pump/turbine freeness checking, observe RPM
9. Stop barring engage/disengage main p/p and do
FW charging
10. Vapour extraction fan i/s

45.  FW charging
1. Open BP/BFP/suction strainer vent
2. Charge mechanical seal water BP/BFP
3. Charge jacket cooling wtr and one set of
cooler
4. Crack open suction v/v *
5. Taking on barring along with FW
charging?
6. Close all drain /vents

46.  Gland seal steam /vacuum side
1. Open aux stm. drain at 8.5 M then crack
charge
2. Open seal steam /aux c/v drain and crack
charge 8.5 m iso. v/v
3. Charge seal stm / leak off stm side
4. Open turbine drains to flash tank to take
vacuum
5. Crack open exhst. block v/v and close ,try
again
 Extraction stem side
1. Open drain/vent before ESV
2. Open manual v/v
3. Open mot. v/v