摘要 |
An abradable coating and/or an abrasive coating applied to the rotor of a steam or gas turbine allows the temperature and pressure drop capabilities of conventional brush seal assemblies to be increased. The pressure drop capability of brush seals is closely related to fence height, i.e., the distance between the rotor and the bottom edge of the backing plate supporting the brush seal wire bristles. Application of the abradable or abrasive coating allows the fence height to be reduced and the pressure capability of a brush seal assembly increased commensurately because the risk of the backing plate rubbing against the surface of the rotor, so as to cause damage to the rotor, is reduced. In addition, the backing plate can be made from a higher strength material that can withstand higher temperatures because any contact between the backing plate and the rotor results in no damage to the rotor, but rather a gradual reduction of the backing plate as it wears.
|