Pump failures
Pump failures
(OP)
I have an Acid system in our steel pickling line. 4 pumps in parallel pumping 18% acid to a '6 storey tower' Each floor of the tower have 4 sets of spray headers. So many pumps failed, and replacing these pumps cost a lot of money and management is giving us a lot of pressure. We hooked up the motor and take the horsepower reading and observe changes. The Hp required for all 4 pumps showing they are running on the 'left' side, or low flow side of the curve. A while later, one pump starting to fail, Hp dropped by 10. I didn't hear any cavitation noise while the pumps are running, even though it is cavitation, shouldn't it deteriorate before Hp dropped in a sudden? Also, is there another explaination for sudden drop of Hp of a centrifugal pump, which means pumping less flow, other than suction blockage? Thanks.





RE: Pump failures
A description of the "damage" to the pumps or better still some photo's will greatly help.
Phitsanulok
Thailand
RE: Pump failures
RE: Pump failures
Thanks for your advise. I don't know how to load pictures onto this chat room unfortunately. I do have some pictures of failed impellers. The impellers are made of Fibre glass. The acid is 18% HCL and SG is 1.15.
To Artisi:
I worked on this with my Piping Engineer, learning it from the pump curve, without flowmeters, individual discharge and inlet pressure gauges (have one common discharge pressure gauge), there is nothing we can do. I am curious to know why did the Hp dropped in all of a sudden, but there were no excessive noise or vibration that can be detected. That's what puzzles me.
Thanks
RE: Pump failures
RE: Pump failures
RE: Pump failures
" it just puzzles me to what happen to the pumps when no significant noises were detected by Amp draw dropped significantly"
See the comment below from JJPellin - does this mean anything to you.
"he metal hub imbedded in the fiberglass impeller would tear loose and the impeller would stop spinning."
Phitsanulok
Thailand
RE: Pump failures
We manufacture pumps in Polypropylene and PFA for such applications and have many years success, however, these are virgin material with no mechanical fillers, which tend to be the weak point of non-metallic pumps.
If you have continued failures, it will be worth investigating the virgin Polypropylene line as they will tend to be a lot cheaper than St Steel, but more importantly, more reliable in the long term.
visit www.cdrpumps.co.uk and click on applications to see similar applications.
Hope this helps in some way ?
RE: Pump failures