Turbine Case Carbon Seals Bearing Housing/Pedestal Beari ng
Turbine CaseCarbon Seals
Bearing Housing/Pedestal
Bearing
Turbine CaseCarbon Seals
Bearing Housing/Pedestal
Bearing
Turbine CaseCarbon Seals
Bearing Housing/Pedestal
Bearing
230 degrees f.230 degrees f.
Temperature
Turbine CaseCarbon Seals
Bearing Housing/Pedestal
Bearing
230 degrees f.230 degrees f.
Temperature
Steam
Turbine CaseCarbon Seals
Bearing Housing/Pedestal
Bearing
230 degrees f.230 degrees f.
Temperature
Steam Seal FailureSeal Failure
Condensate Magnet
Turbine CaseCarbon Seals
Bearing Housing/Pedestal
Bearing
Steam moves out of the case, down the shaft and past the carbon seals to atmosphere.
Steam Path
Turbine CaseCarbon Seals
Bearing Housing/Pedestal
Bearing
Some steam dissipates into the atmosphere. In some instances (such as in cold climates), this could cause a visibility hazard.
Turbine CaseCarbon Seals
Bearing Housing/Pedestal
Bearing
It could also cause a slipping hazard as condensate collects on the ground, or can cause severe burns if contacted near the exhaust path.
Turbine CaseCarbon Seals
Bearing Housing/Pedestal
Bearing
Lost steam is also money thrown into the wind.
$$$$$$$$$$
$$$$$$$$$$
Turbine CaseCarbon Seals
Bearing Housing/Pedestal
Bearing
Yet another consideration – if water enters your bearing housing, the integrity of your oil (lubrication system) will be compromised.
Turbine CaseCarbon Seals
Bearing Housing/Pedestal
Bearing
This could lead to bearing failure and ultimately, equipment failure.
Turbine CaseCarbon Seals
Bearing Housing/Pedestal
Bearing
When shaft seals fail, your only barrier against oil contamination are your bearing case seals.
Condensate Magnet
Turbine CaseCarbon Seals
Bearing Housing/Pedestal
Bearing
These seals can be standard OEM “H” seals, or “upgrades” such as modified “H” seals (Disrupter Seals) or aftermarket Barrier Seals.
Condensate Magnet
Solutions
Try to reduce or eliminate steam leakage at the source.
Solutions
Protect your oil from contamination.
The standard shaft seals on most small steam turbines are carbon rings.
Carbon Seals
If installed correctly, they provide a good seal. However they do deteriorate rapidly.
Carbon Seals
Effective Clearance Over Time
Carbon RingsAdvantagesAdvantagesInexpensiveInexpensiveEasy to installEasy to installPerform well when Perform well when properly sized and properly sized and installedinstalledLightweightLightweight
DisadvantagesDisadvantagesEasily cracked/ Easily cracked/
chippedchippedIf not properly If not properly
sized, can either sized, can either seize on shaft or seize on shaft or leak too muchleak too much
Short life, resulting Short life, resulting in high leakage in high leakage after short timeafter short time
Mechanical Seals
AdvantagesAdvantagesBest sealing performanceBest sealing performanceLonger life than standard Longer life than standard
carbon sealscarbon seals
DisadvantagesDisadvantagesExpensive initial investmentExpensive initial investmentDifficult to install, requires Difficult to install, requires
entire rotor to be removed entire rotor to be removed for installation/ maintenancefor installation/ maintenance
Can require permanent case Can require permanent case modificationsmodifications
Finite life-span before a Finite life-span before a costly overhaul is required.costly overhaul is required.
Mechanical Seals
Brush Seals
Brush SealsAdvantages
Moderately pricedModerately pricedMore durable than carbon More durable than carbon
sealssealsExtremely long lifeExtremely long life
Disadvantages Must be installed in shopMust be installed in shop Not stocked for all size Not stocked for all size
turbinesturbines Relatively new technology Relatively new technology
for steam applicationsfor steam applications Heavy “floating” seals can Heavy “floating” seals can
gravitate downward on gravitate downward on turbines that cycle, thus turbines that cycle, thus decreasing efficiencydecreasing efficiency
Brush Seals
Utility Turbines Utility Turbines Mechanical Drive TurbinesMechanical Drive TurbinesGas Turbines – Aircraft & IndustrialGas Turbines – Aircraft & IndustrialSingle Stage TurbinesSingle Stage Turbines
Elliott – All YR sizesElliott – All YR sizesDresser RandDresser RandGeneral ElectricGeneral ElectricWestinghouseWestinghouse
Current Applications
Brush SealsThe bristles, which run at "zero clearance", are oriented at an angle to the turbine rotor. The angle is in the direction of rotor rotation.
Benefits A typical brush seal is roughly comparable to a labyrinth tooth at a radial clearance of 0.005". Compare this value of the 0.015"to 0.025" design radial clearance often found on the stage packing of many units, one can see where brush seals could create substantial efficiency gains and reduced leakage.
Brush Pack
RotationShaft
Brush Pack
Holder
FenceFlow
Brushes are a Haynes 25 material
Holder is SS
The typical brush seal design consists of a pack of fine wire bristle material sandwichedbetween two plates. The two plates (or washers as they are commonly called) and thebrush pack are then joined together.
Little or no case modifications beyond original design specifications.
Lower sustained leakage than carbon rings.
Indefinite life span eliminating periodic replacement.
Brush Seals
Brush SealsInstallation Considerations
Sealing faces and ID Sealing faces and ID of carbon box areof carbon box aremachined to assuremachined to assurea good seal fit.a good seal fit.
Sealing faces and ID Sealing faces and ID of carbon box areof carbon box aremachined to assuremachined to assurea good seal fit.a good seal fit.
29Compressor & Turbine Services. LLC
Internal Alignment is ImportantInternal Alignment is ImportantInternal Alignment is ImportantInternal Alignment is Important
30Compressor & Turbine Services. LLC
On Fixed (non-floating) Brush SealsOn Fixed (non-floating) Brush Seals
Suggested Shaft Coatings – Suggested Shaft Coatings –
None – Base MetalNone – Base Metal
Chromium CarbideChromium Carbide
Tungsten CarbideTungsten Carbide (preferred) (preferred)
31Compressor & Turbine Services. LLC
32Compressor & Turbine Services. LLC
Leakage Data From SST Test
Test comparing brush seals with cold (new) carbon seals
Brush seals installed with “zero” clearance
Carbon seals installed with 2.5 mil radial clearance
Carbon seals exhibit equivalent clearance of 4.3 mils
B = Brush Seal C = Carbon Seal
33
Effective Clearance over Time
34Compressor & Turbine Services. LLC
Brush Seals vs. Carbon Rings
0
1
2
3
4
5
6
7
8
9
10
Start-Up One Month Six Months
Carbons
Brush Seals
Effective Clearance over TimeEffective Clearance over Time
Carbon seals will degrade almost immediately. Brush seal performance will always stay the same.
35Compressor & Turbine Services. LLC
36Compressor & Turbine Services. LLC
Brush Seals for Steam TurbinesBrush Seals for Steam Turbines May be used as a May be used as a replacementreplacement for for Carbon RingsCarbon RingsOrOr May be used May be used in conjunctionin conjunction with with Carbon Rings Carbon Rings
38Compressor & Turbine Services. LLC
Application: Brush Seals to Replace Application: Brush Seals to Replace Carbon RingsCarbon Rings
Non Floating SealsNon Floating Seals
COST:COST:
Around $10kAround $10k
Per SSTPer SST
COST:COST:
Around $10kAround $10k
Per SSTPer SST39Compressor & Turbine Services. LLC
Application: Brush Seals to Replace Application: Brush Seals to Replace Carbon RingsCarbon Rings
More Risky Than Brush/Carbon Combination Since Brush Seals DO
NOT Have a History for this Application. Only recommended for
turbines that are in continuous service.
(floating seals)
More Risky Than Brush/Carbon Combination Since Brush Seals DO
NOT Have a History for this Application. Only recommended for
turbines that are in continuous service.
(floating seals)
40Compressor & Turbine Services. LLC
Application Requirements:Application Requirements:Brush Seals as Brush Seals as ReplacementReplacement for carbon for carbon
ringsrings
Minimum radial space Minimum radial space between shaft and packing between shaft and packing box ID of 1.0 inch typicallybox ID of 1.0 inch typically
Maximum pressure drop Maximum pressure drop across one seal is 150 psidacross one seal is 150 psid
Packing box must be Packing box must be reasonably aligned with reasonably aligned with bearingsbearings
Best used on turbines that are Best used on turbines that are in continuous operationin continuous operation
Drain
Brush Seals
41
Anti-rotation pinAnti-rotation pin
Split lineSplit lineBrushesBrushes
Sealing faceSealing face
42Compressor & Turbine Services. LLC
Application: Brush Seals to Replace Application: Brush Seals to Replace Carbon RingsCarbon Rings
Non Floating SealsNon Floating Seals
Elliott BYRHHElliott BYRHH
43Compressor & Turbine Services. LLC
Flow
Drain PipeDrain Pipe
No.1No.1
No.2No.2
No.3No.3
44Compressor & Turbine Services. LLC
45Compressor & Turbine Services. LLC
46Compressor & Turbine Services. LLC
Estimated around 100 turbines in operation with Brush Seals in this configuration.
No case modifications beyond original design No case modifications beyond original design specifications.specifications.
Lower sustained leakage than stand-alone carbon Lower sustained leakage than stand-alone carbon rings. rings.
Indefinite life span eliminating periodic Indefinite life span eliminating periodic replacement.replacement.
Protects carbon rings from contaminationProtects carbon rings from contamination
Reduces pressure on carbon ringsReduces pressure on carbon rings
Brush Seals/Carbon Rings - A Brush Seals/Carbon Rings - A
Winning CombinationWinning Combination
47Compressor & Turbine Services. LLC
Leakage Data From SST Test
Test comparing brush seals with cold (new) carbon seals
Brush seals installed with “zero” clearance
Brush seals exhibit equivalent clearance of 3.4 mils radial
Carbon seals installed with 2.5 mil radial clearance
Carbon seals exhibit equivalent clearance of 4.3 mils
B = Brush Seal C = Carbon Seal
48
Solid Ring Solid Ring DesignDesign
Solid Ring Solid Ring DesignDesign
COST:
Around $ 3k – 6k
COST:
Around $ 3k – 6k
49Compressor & Turbine Services. LLC
Brush SealsInstallation Considerations
Single Stage Turbine Brush Seal Benefits - Single Stage Turbine Brush Seal Benefits -
When used with carbon ringsWhen used with carbon rings
Brush Seal used to protect carbon rings
Carbon rings
Protects carbons 1) by reducing steam pressure.
2) Reducing particulate contamination.
One Brush Seal ring required upstream of carbons on both ends
51Compressor & Turbine Services. LLC
Single Stage Turbine Brush Seal Benefits - Single Stage Turbine Brush Seal Benefits -
When used with carbon ringsWhen used with carbon rings
Brush Seal used to protect carbon rings
Carbon rings
Protects carbons 1) by reducing steam pressure.
2) Reducing particulate contamination.
One Brush Seal ring required
before the bleed-off.
52Compressor & Turbine Services. LLC
53Compressor & Turbine Services. LLC
Standard Brush Seal CTS Brush Seal
No case modifications beyond original design specifications.
Lower sustained leakage than stand-alone carbon rings.
Increased run-time.
Protects carbon rings from contamination
Reduces pressure on carbon rings
Single Stage Turbine Brush Seal BenefitsSingle Stage Turbine Brush Seal Benefits
To complement carbon ringsTo complement carbon rings
54Compressor & Turbine Services. LLC
The Result is
Reduced
Maintenance
Costs
The Result is
Reduced
Maintenance
Costs55Compressor & Turbine Services. LLC
Our Sealing SystemsOur Sealing Systems
Brush SealsBrush Seals
•Designed & Manufactured at our facility•Light weight “floating” seal•Available for Elliott “YR” turbines (and many others)•Custom applications
Early non floating Brush Seal
Typical Carbon Ring
Steel Cased Brush Seal
CTS Brush Seal
Carbon
Brush Pack
CTS Brush Seals are lighter than traditional Brush Seals. In addition you have the benefits of two carbon rings and one Brush in each turbine slot. Eliminates the problems caused by heavier Brush Seals on turbines that cycle.
Disrupter SealsDisrupter Seals
•Designed & Manufactured at our facility•Superior design to reduce moisture in bearing housing•Cost effective
Support American owned small businesses!Support American owned small businesses!
Turbine CaseCarbon Seals
Bearing
CTS “Disrupter” Seals deflect moisture away from the bearing housing by disrupting the steam that moves down the shaft.
Steam
Steam
62Compressor & Turbine Services. LLC