Steam Turbine Seal Upgrades
EthosEnergy’s patented retractable brush seal incorporates a unique brush seal element that operates with a “zero” clearance when closed, creating a tight maze of bristles that block the flow of steam and provide improved performance over original design.
Steam leakage at the rotor shaft occurs due to rubs on the packing rings during unit start-up. Conventional packing rings frequently are found worn to an excessive clearance causing significant degradation in steam turbine efficiency and performance. Application of our advanced seals help improve and maintain your unit efficiency while providing potential benefits in reliability, availability and reduced emissions. To achieve maximum improvements each turbine is individually evaluated for the best seal package. The retractable brush packing reduces leakage and successfully increases efficiency and output.
What can we do to help?
By measuring the rotors and seal holders, EthosEnergy can custom size the seals for your unit to ensure optimum performance. The retractable feature of this upgrade allows a large clearance for turbine start up where rubs typically occur, saving the seals for long term efficient operation.
With our patented Retractable Brush Packing the original design springs that are placed behind the segments and hold them in place are eliminated allowing the packing to expand outward into the holder for start-up. Coil springs in the ends of the segments exert an outward force increasing packing clearance until unit has gone through critical vibration and steam load is put into the steam path. The delta in steam pressure across the packing location overcomes the coil spring force closing the ring down to design clearance with the sharp labyrinth teeth intact reducing steam leakage along the rotor shaft.
EthosEnergy also provides custom installation of our upgraded seals for your unit to ensure optimum performance. The retractable feature of this upgrade allows a large clearance for turbine start up where rubs typically occur, saving the seals for long term efficient operation.
Retractable brush seals consist of fine wire bristles sandwiched between two side plates. The bristles, which operate at zero clearance, are oriented at an angle in the direction of shaft rotation. The back plate provides support for the brush pack and prevents the bristles from being deflected downstream by the pressure of the steam across the seal. A pressure balanced cavity is machined into the backplate, which allows the seal to remain flexible in higher pressure applications.
Why choose EthosEnergy Retractable Brush Seals?
The application of EthosEnergy’s SMART Seals™ improves and maintains unit efficiency, and provides potential benefits in reliability, availability and emission reductions. By applying retractable brush seals, clearances can be reduced from a typical 0.025” (0.635mm) design to an effective clearance of 0.002” (0.0508 mm). Other benefits include:
- Mitigation of rubs caused by tight seal clearances at start-up
- Bristle flexibility that allows for rotor excursions at load
- Increased steam turbine efficiency & reduced degradation
- More reliable unit start-ups
- Fuel savings benefited from reduction in heat rate
- Reduced emissions due to reduced fuel consumption
- Potential revenue increase from higher power output
- Custom fit seals to account for holder deviations or distortions
- More flexible unit cycling
Get in touch today and discover how we can help your steam turbine needs!