Crystal Instruments Rotating Machinery Testing

Rotating machinery spends long periods in steady-state operation, and the vibration signatures recorded by a continuous monitoring system capture problems such as imbalance from blade erosion or loading, and misalignment caused by thermal cycling. Steady-state data alone, however, may not reflect the subtler degradation a machine experiences with age and wear. Every time a processing train stops or starts, there is an opportunity to learn much more about its mechanical health.

The Crystal Instruments rotating machinery solution is built around these transient events. The system measures 3D vibration waterfalls (amplitude versus frequency versus time or RPM), exposing responses that stay hidden under steady-state operation. Using a tachometer signal to order-normalize the measurements makes the relationship between fixed-frequency resonances and rotation-related forcing functions easy to understand. Brief instabilities such as shaft whirl and whip encountered during transient operation indicate the need to inspect bearings and adjust lubricant pressures.

Together with diagnostic displays such as the orbit diagram, the approach gives a clear picture of shaft and bearing problems, including dry rub, oil whirl and various misalignments. Capabilities include commissioning and shutdown waterfalls, order tracks (the amplitude of an order versus RPM), order-normalized spectra, orbit diagrams, reanalysis of recorded data, and one- and two-plane rotor balancing. The usual hardware is the CoCo-80X handheld dynamic signal analyzer, the Spider-80Xi high-channel-count dynamic signal analysis system and Spider-NAS storage, while the software includes EDM Post Analyzer for replaying recordings, EDM Order Tracking and EDM Rotor Balancing.