摘要 |
A butterfly valve for controlling the flow of high temperature fluids includes a valve body defining a flow path and having opposed portals. Cover plates are mounted over each of the portals and have a conical shaped wall extending inward to a bearing support member. A flow modulator is disposed between the cover plates and is mounted to the bearing support members by ceramic bearings. The modulator has a plate disposed in said flow path which is bounded by a leading edge, a trailing edge, and two disk flanges. Each of the disk flanges has a labyrinth seal in sealing engagement with an inner wall of said valve body. Nozzles are mounted to said cover plate to deliver cooling air flow to the bearings. A constant cooling flow rate is maintained by appropriately sized circumferential chambers adjacent each of the labyrinth seals.
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