Good day all,
The suituation: A mag drive pump has been installed in the plant and is the bottoms pump for a vessel. The pump liquid is Ethane and condensate. On start-up of the pump the pump fails due to journal bearing failure. The bearing is contained within a silicon carbide sleeve which runs against a carbon graphite housing which is attached to the impeller back-plate.
Hence liquid (Ethane and condensate) is directed to the volute casing(suction), then to the discarge of the mag drive pump, whereby a certain quantity is routed to the filter to remove solids then to a cooler. After cooling the liquid, the liquid is routed through channels to the journal bearing (cooling and lubrication) and between the magnets for cooling. Once this stage is completed the liqiud exits the internals of the pump via a hole drilled through the centre of the shaft of the pump.
The problem: The journal bearing has failed on start-up of the pump. The bearing is able to handle radial and axial thrust developed. Approximate time of running before failure : 40 to 90secs.Also note that the temperature of the liqiud being pumped is -52deg. celcius.
Pump specifications:
Suction pressure: 460Kpa(g)
Discahrge pressure: 1437Kpa(g)
NPSHa: 4.3m
Differential head: 203m
Vapour pressure:519Kpa(A)
Specific gravity: 0.492
Viscosity: 0.11Cp @ -52deg celcius
Rated power: 48.55KW
Efficiency: 46%
Question: I require your help(just brainstorming) to determine what could be wrong with this set-up???
Also does anyone know of a Anthony E. Stavale, he has published some very interesting papers on magnetic drive pumps, bearing materials, extreme operating conditions of mag drive pumps and dry running of silicon carbide bearings.
Below is a list of his papers that i require.
-Managing extreme requirements with plastic magnetic coupling pumps
-Dry running test utilizing silicon carbide bearings and polymer lubricated strips with conductive and nonconductive containment shells in an ANSI magnetic drive pump.
-Analysis and testing of alternative bearing materials for application in sealless pumps.
Thanking you all for your help.
Mech225
The suituation: A mag drive pump has been installed in the plant and is the bottoms pump for a vessel. The pump liquid is Ethane and condensate. On start-up of the pump the pump fails due to journal bearing failure. The bearing is contained within a silicon carbide sleeve which runs against a carbon graphite housing which is attached to the impeller back-plate.
Hence liquid (Ethane and condensate) is directed to the volute casing(suction), then to the discarge of the mag drive pump, whereby a certain quantity is routed to the filter to remove solids then to a cooler. After cooling the liquid, the liquid is routed through channels to the journal bearing (cooling and lubrication) and between the magnets for cooling. Once this stage is completed the liqiud exits the internals of the pump via a hole drilled through the centre of the shaft of the pump.
The problem: The journal bearing has failed on start-up of the pump. The bearing is able to handle radial and axial thrust developed. Approximate time of running before failure : 40 to 90secs.Also note that the temperature of the liqiud being pumped is -52deg. celcius.
Pump specifications:
Suction pressure: 460Kpa(g)
Discahrge pressure: 1437Kpa(g)
NPSHa: 4.3m
Differential head: 203m
Vapour pressure:519Kpa(A)
Specific gravity: 0.492
Viscosity: 0.11Cp @ -52deg celcius
Rated power: 48.55KW
Efficiency: 46%
Question: I require your help(just brainstorming) to determine what could be wrong with this set-up???
Also does anyone know of a Anthony E. Stavale, he has published some very interesting papers on magnetic drive pumps, bearing materials, extreme operating conditions of mag drive pumps and dry running of silicon carbide bearings.
Below is a list of his papers that i require.
-Managing extreme requirements with plastic magnetic coupling pumps
-Dry running test utilizing silicon carbide bearings and polymer lubricated strips with conductive and nonconductive containment shells in an ANSI magnetic drive pump.
-Analysis and testing of alternative bearing materials for application in sealless pumps.
Thanking you all for your help.
Mech225
