Brushing Up on Brush Seals

摘要

Like the television sets from the 1950s, traditional steam turbine seals have largely gone the way of the "rabbit ears" in favor of more modern designs. TurboCare SMART Seals, for instance, include retractable packing, retractable brush seals, brush tip seals, articulated inlet pipe seals and horizontal joint sealing solutions. Brush seals like these have become an accepted tool for bringing stage performance beyond original specifications. With brush seals having logged hundreds of thousands of hours of run-time, a body of work exists for a detailed study to determine what works well in the field and the lessons learned. Following three years of development and testing, the first retractable brush seals were installed on a production steam turbine in 1999 with more than 150 large utility and mechanical drive units to follow. The latest generation of brush seals incorporates several proprietary improvements to further reduce bristle flutter and density loss.