kmg1983
Mechanical
- May 21, 2007
- 34
Hello all...
Currently we have a single stage, horizontal centrifugal pump which pumps brine...it runs at about 1190 rpm.
I gathered vibration data on the outboard pump because the pump kept shutting down on high vibration. The resulting spectra in the horizontal, vertical, and axial directions had the following characteristics:
Horiz: Raised noise floor from 300-20,000 CPM; significant peak at 4770 CPM (which turns out is blade pass freq.) = .135 ips, minor raised noise floor from 20kCPM-60kCPM
Vert: More significant raised noise floor from 0-10,000 CPM then drops off drastically (flow turbulence?), again peak at blade pass frequency = 0.035 ips, raised noise floor around 60kCPM
Azial: Significant raised noise floor from 0-10,000 CPM, smaller raised noise floor throughout rest of spectrum, again peak at 4770 CPM with amplitude of 0.054 ips
There are no indications on the spectra of bearing frequencies, unless they are mixed up with the raised noise floor further out in the spectrum.
Anyone have any thoughts on to what may be causing such vibrations?
I must also mention that earlier during the day, this particular pump would run for some time, then instantaneously shutdown on high vibrations...
I'm new to vibration analyzation and am unsure as to what may be causing this ? Any input is greatly appreciated.
Currently we have a single stage, horizontal centrifugal pump which pumps brine...it runs at about 1190 rpm.
I gathered vibration data on the outboard pump because the pump kept shutting down on high vibration. The resulting spectra in the horizontal, vertical, and axial directions had the following characteristics:
Horiz: Raised noise floor from 300-20,000 CPM; significant peak at 4770 CPM (which turns out is blade pass freq.) = .135 ips, minor raised noise floor from 20kCPM-60kCPM
Vert: More significant raised noise floor from 0-10,000 CPM then drops off drastically (flow turbulence?), again peak at blade pass frequency = 0.035 ips, raised noise floor around 60kCPM
Azial: Significant raised noise floor from 0-10,000 CPM, smaller raised noise floor throughout rest of spectrum, again peak at 4770 CPM with amplitude of 0.054 ips
There are no indications on the spectra of bearing frequencies, unless they are mixed up with the raised noise floor further out in the spectrum.
Anyone have any thoughts on to what may be causing such vibrations?
I must also mention that earlier during the day, this particular pump would run for some time, then instantaneously shutdown on high vibrations...
I'm new to vibration analyzation and am unsure as to what may be causing this ? Any input is greatly appreciated.
