Pump Blade Resonance Problem
Resonance at pump blade pass frequency (BPF) was reduced by increasing speed, but process balance was affected.
Resonance Of Pump Blade pass frequency
Resonance occured when natural frequency is coincide with frequency dominant (1X, 2X, 5X and others)
Resonance can reduced with:
1. Change speed (If type driver is motor VSD or support to adjust speed)
2. Add mass
3. Add stiffness
I have case with problem resonance at pump with driver VSD Motor, i take FRF bump test data on part of pump (casing, bearing housing, pipe, cover coupling, foundation and others) from all part, i have match data FRF bump test from bearing housing with NF 174 Hz or coincide BPF when running about 1770 rpm number of blade is 6 (BPF is 174Hz)
Trouble shoot with change the speed increased upper 15% of resonance with speed 2200 rpm, high vibration at resonance BPF is 9.5 mm/s rms, and after change speed vibration of BPF is reduce to 2.5 mm/s rms, however we have balance of process or flowrate required
Many case of resonance at pipe, when resonance occured at pipe system, the most recommendation is add stiffness or support for reduce resonance
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