US Patent 7854584 Barrier sealing system for centrifugal compressors

A rotary machine includes a machine rotor, a bearing coupled to the machine rotor, a machine stator, and a sealing device disposed between the machine rotor and the machine stator. The sealing device includes a dry gas seal and first and second seals disposed between the dry gas seal and the bearing. One or both of the first and second seals includes a brush seal or more specifically a brush seal including a plurality of non-metallic fibers.