Application Review

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Industry
Power Generation
End User
Indianapolis Power & Light

Application Details

In March of 2002, Indianapolis Power and Light tested Treo in a side-by-side trial with ceramic fiber blanket. Both materials were layered to a thickness of 1½" in encapsulated covers to be used in the steam turbine area. The specific location that was chosen for the test was the Intercept Valves, which control the flow of 1005™F steam into the turbine. There are two identical valves, approximately 42” in diameter, and combined, they control the ingress of steam directly into the turbine. The pressure and flow is identical, so the temperatures are the same inside each valve.

Application Challenges

The reason for selecting this application for test, was that the ceramic insulation currently used, was disintegrating and compacting due to vibration, leaving areas within the cover "thin" and un-insulated. This phenomenon is believed to be accelerated by the high shot content in ceramic blanket, which acts as an abrasive within the blanket.

Application Solution

Engineers ordered a cover identical in construction to the cover filled with ceramic fiber. This test pad utilized 1½" inches of encapsulated TreoTM as the primary insulating material.

Results and Impact

In order to determine whether the insulation was compacting due to vibration, an infrared thermal gun was used to check surface temperatures on the cold face of each cover. The higher temperatures on the ceramic fiber cover are an indication of the breaking down of the ceramic fibers.

Cold Face Infra-red Readings

Cold Face Infra-red Readings
Steam Line Throttle Valves
Insulation Material Intercept Valve Sample point 1 Sample point 2
Treo™ 240°F 220°F 170°F
Ceramic Fiber 480°F - 530°F 250°F - 260°F 200°F

Other areas on the Throttle Valves were scanned and showed a consistent delta of 30°F between the two configurations, with Treo™ being the more favorable. By having a low shot content; Treo™ outperformed ceramic fiber and provided a safe alternative to the workers at Indianapolis Power & Light.