Augmented Labyrinth Brush Seals
Reduce Clearances, Improve Efficiency
Augmenting labyrinth seals with brush seals is a simple and effective approach to reducing clearances and eliminating potential problems from shaft contact wear.
The Benefits of Compliancy
Over time, labyrinth seal clearances are compromised through erosion and material removal, which can stem from factors such as:
- Rotor-stator interaction (due to high imbalance loading)
- Transient excursions (due to asymmetric thermal growth between the rotor and casing)
In addition, since labyrinth seals are rigid geometry seals and are not capable of bending to accommodate rotor excursions, design clearances are engineered to account for all phenomena affecting clearance closures in the machine.
The brush seal’s compliancy – its ability to bend – allows sealing clearances to be significantly reduced, thus increasing machine efficiency and power.
Advantages
- Reduce initial leakage by 50% compared to straight labyrinth seals, or by 30% compared to interlocking labyrinth seals
- Eliminate steam leaks and the safety hazards associated with high temperatures and toxic gases
- Reduce condenser capacity and space requirements in new steam turbines
- Require less axial space than labyrinths
- Easily installed and field serviceable in a variety of sealing environments
- Allow a “wear-in” to minimal clearance through flexible sealing mechanism
- Standard components for cost-effectiveness and timely shipment
