Labyrinth seal into two halves Labyrinth Seal.
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Transcript of Labyrinth seal into two halves Labyrinth Seal.
Labyrinth seal into two halves
Labyrinth Seal
Labyrinth Seal
•Labyrinth seals
Labyrinth seal consist of a series of circumferential strips of soft metal extending from the shaft housing
(or the rotor housing).
Labyrinth seals are used in gas turbines in two different areas:
In the turbine section, to perform sealing around the rotor. Its job is to minimize escape of gases from high pressure
area to low pressure area.
In the bearing housing, to minimize escape of pressurised air to outside.
If the pressurized air escapes, the lube oil will escape too.
RADIAL TILTING PAD BEARING
RADIAL TILTING PAD BEARING
SHAFT
CASING
Radial Load
Oil WedgeOil Wedge
Shaft
Friction EffectOil Wedge Effect
Oil WedgeOil Wedge
Oil adhere to the rotating shaft
Oil squeeze between shaft and bearing pad forming a solid
oil wedge
RADIAL TILTING PAD BEARING
RADIAL TILTING PAD BEARING
PIN
CASING
OIL
TILTING PAD
SHAFT
RADIAL MAGNITIC BEARINGRADIAL MAGNITIC BEARING
THRUST MAGNITIC BEARINGTHRUST MAGNITIC BEARING
Gas Compressors Sealing SystemGas Compressors Sealing System
COOLER
SCRUBBER
1St Stage
ANTI-SURGE VALVE
COOLER
SCRUBBERANTI-SURGE VALVE
COOLER
SCRUBBERANTI-SURGE VALVE
SCRUBBER
2 Nd Stage 3 Rd Stage
**Centrifugal Compressor Operation **Centrifugal Compressor Operation
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General aspectsGeneral aspects1- A Complete spare balanced rotor to be ideally stored in W.H 2- Compressor will be equipped with a complete surge control system.3- It is advisable to use dry gas seal system instead of wet seal one.
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Compressor Sealing System
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1- Wet seal system ( USINGOILFOR SEALING THE GAS )
1- Wet seal system (USING OIL FOR SEALING THE GAS)
2- Dry Gas Seal ( COMPRESSORGASUSED FOR SEALING THE GAS )
2- Dry Gas Seal (COMPRESSOR GAS USED FOR SEALING THE GAS)
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1 - Wet sealSystem
1 -Wet seal System
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GAS TO FLAREGAS TO FLARE
Drain pot
CLEANSEAL OIL
CLEANSEAL OIL
CLEAN OIL TO
RESERVOIR
CLEAN OIL TO
RESERVOIR
COMPRESSOR GASCOMPRESSOR GASOil sealing system
Oil sealing system
CONTAMINATED OIL TO DISPOSALCONTAMINATED
OIL TO DISPOSAL
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Wet )Oil( sealing system
Wet )Oil( sealing system
GasCompressor rotor
Oil Mech. sealOil Mech. seal
Heater
Oil Tank
Contaminated Oil to disposal
Gas to flare
OIL PUMPS
FILTERS
Drain potDrain pot
19HEATER
SEAL OIL COOLER
FILTERS
OIL PUMPS
SEAL OIL HEAD TANK
REFRENCE LINE
SEAL OIL TANK
Gas to flareGas to flare
Drain pot
Drain pot
Oil to disposalOil to disposal
Oil sealing system
Oil sealing system Opened
20HEATER
SEAL OIL COOLER
FILTERS
OIL PUMPS
SEAL OIL HEAD TANK
REFRENCE LINE
SEAL OIL TANK
Gas to flareGas to flare
Drain pot
Drain pot
Oil to disposalOil to disposal
In case of power failure
In case of power failure
Closed
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Typical Seal Oil Trap ( Drain pot )Typical Seal Oil Trap ( Drain pot )Typical Seal Oil Trap ( Drain pot )Typical Seal Oil Trap ( Drain pot )
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LUBE OIL SYSTEM
LUBE OIL SYSTEM
G box
Electric Motor
Centrifugal Compressor
Lube Oil Drain HeaderTo Main Lube Oil Reservoir
LSC
HSC
From Lube Oil Control Valve
7000 mm Above Machine C/L
Rundown Tank
Lube Supply Oil Header
To Lube Oil Reservoir
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IF THE SEAL IS DETERIORATED, THE SEAL OIL CONSUMPTION WILL INCREASE TO BE MORE THAN
500 LITRES PER DAY.
In case of Wet seal systemIn case of Wet seal system
THE RECOMMENDED SEAL OIL CONSUMPTION IS ABOUT
40 LITRES PER DAY.
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2 - Dry gasseal system
2 -Dry gas seal system
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• NO WEAR DURING ROTATION • NO WEAR DURING ROTATION
StationarStationary Ringy Ring
Wet Seal (contact faces)
Wet Seal (contact faces)
RotatinRotating Ringg Ring
StationarStationary Ringy Ring
RotatinRotating Ringg Ring
Dry gas Seal (Non contact faces)
Dry gas Seal (Non contact faces)
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• NO WEAR DURING ROTATION • NO WEAR DURING ROTATION
ROTATING ELEMENT STATIONARY ELEMENT
GAP
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History of Dry Gas SealsHistory of Dry Gas Seals
• 1925 to 1964 spiral groove bearing technology
• 1968 Curved face seal with spiral grooves
• 1970 Light duty gas seal (Type 28LD) developed for motors
• 1988 Light duty gas seal (Type T28) for gas compressors
• 1992 Introduction of a double gas seal for process pumps
– 1992 Big bore seal chambers
– 1995 Standard bore seal chambers
• 1995 Introduction of a metal bellows gas seal
• 1997 Introduction of High Pressure compressors/pumps seal
• 1997 Introduction of Slow Speed mixer seal
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Rotary Carbon RingsRotary Carbon RingsSpiral GrooveSpiral Groove
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Rotating Mating Ring
Spiral Groove Sealing SurfaceSpiral Groove Sealing Surface
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CarbonRing
TungstenRing
Spiral grooves
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Groove diameter
Spiral grooves
Tungsten carbide ring
(Principle of operation)
Rotating or stationary ring
Rotating or stationary
ring
GAS
Sealing dam
BEFORE ROTATION
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GAS
Rotating or stationary ring
Rotating or stationary
ring
AFTER ROTATION
Groove diameter
Spiral grooves
Sealing dam
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Gas Rushes into spiral grooves
Gas
Gas
Gas
Gas
Gas
Gas
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Spiral Groove OperationSpiral Groove Operation
• Gas pressure rises along spiral grooves
• Contact eliminated
• Cushion of gas
separates sealing faces
Gas Enters And is Induced Towards the Center
Gas is Compressed and Pressure Increases to Set Sealing Gap
Sealing Dam
Rotational direction
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HOW DRY SEAL
WORKS
HOW DRY SEAL
WORKS
P Port 1
Separation barrier
Port 2 Port 3 Port 4 Port 5
Inner seal
Outer seal
Labyrinths
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Filtered process gas inlet process gas
+buffer gas TO FARE
Supply of buffer gas
VENT
buffer gas to separation barrier
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P4
P4
Filtered process gas inlet
Filtered process gas inlet
Balancing Pressure
Room
Balancing Pressure
Room
Ph
PhPs
Ps
BALANCING DRUM
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P
Separation barrier
Inner seal
Outer sealLabyrinths
Port 3 Port 5Port 4
Port 1
Note 2: Velocity 3 – 5 m/s
Port 1 : Filtered process gas inlet
Port 2 : PRIMARY VENT To flare process gas + buffer gas
Port 3 : Supply of buffer gasPort 4 : SECONDRY VENT
Port 5 : Buffer gas to separation barrier
Port 2
Note 1: Maintain a differential of 0.2 barP
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2 -Low pressure in primary vent
( Port2) due to defective secondary seal.
2 -Low pressure in primary vent
( Port2) due to defective secondary seal.
REMARKSREMARKS PPort 1
Separation barrier
Port 2
Port 3 Port 4 Port 5
In seal
Out seal
1- High pressure )due to excess flow(
in primary vent.
2- Low buffer gas pressure.
1- High pressure )due to excess flow(
in primary vent.
2- Low buffer gas pressure.
ALARMALARM1 -High diff. P across
filter of:
afiltered process gas - .
b.buffer gas -
1 -High diff. P across
filter of:
a- filtered process gas .
b- buffer gas.
ALARM and TRIPALARM and TRIP
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3 -BUFFER GAS TO SEPARATION ZONE
TO PREVENT JOURNAL BEARING OIL TO GET IN MECHANICAL SEAL
1-FILTERED GAS
TO PREVENT PRODUCT GAS LEAK
2 -SUPPLY OF BUFFER GAS ) N2 OR AIR (
TO PRVENT FILTERED GAS LEAK
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SealChamber
FlowMeter
Non-Contacting Seals
Dry Nitrogen CircuitDry Nitrogen Circuit
BallValve
PressureGage
PressureRegulator
NitrogenSource
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Mechanical seal and bearings arrangementMechanical seal and bearings arrangement
oilnitrogen
EquipmentEquipment
nitrogenSeal gas
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WHY TO USE DRY SEAL INSTEAD OF WET SEALWHY TO USE DRY SEAL INSTEAD OF WET SEAL
• PERMITS HIGHER VELOCITY&PRESSURE
• NO SEAL OIL CONSUMPTION
• NO GAS / OIL CONTAMINATION
• NO WEAR
• LOW POWER CONSUMPTION
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Dry Gas seal is
a self adjusting Seal
Dry Gas seal is
a self adjusting Seal
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Spiral grooves
Groove diameter
Inner diameter
Sealing dam
Rotating ringTungsten carbide
)Principle of operation(
Rotating ring
Carbon ring
GAS
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Closing forceFC
Spring load
Productpressure
Forces acting on the sealForces acting on the seal
Compression
Expansion
Gas filmPressure distribution
FOOpening forceFC = FO
Normal operation
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If Gap increasedIf Gap increased
Closing forceFC
Spring load
Productpressure
Compression
Expansion
Gas filmPressure distribution
FOOpening force FC FO
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Closing forceFC
Spring load
Productpressure
Compression
Expansion
Gas filmPressure distribution
FOOpening force
Gap will be reducedGap will be reduced
FC FO
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Back To Normal operationBack To Normal operation
Closing forceFC
Spring load
Productpressure
Compression
Expansion
Gas filmPressure distribution
FOOpening forceFC = FO
Normal operation