Submersible Cryogenic Pumps
Barber-Nichols,
Inc. (BNI) designs and manufactures highly reliable Submersible Cryogenic Pumps for applications
where heat leak is not of great concern. Typical applications of the submersible cryogenic pump include vehicle fueling, fluid destratification,
and the transfer of densified rocket engine propellants. These compact, economical pumps will
endure thousands of start/stop cycles and provide many years of maintenance free operation.
Three main features make these pumps extremely reliable and user friendly. First, BNI designs these pumps so that the harsh cryogenic environment is used to their advantage. The cryogenic working fluid is used to lubricate the pump's bearings and keep its motor cool. Barber-Nichols has been lubricating bearings with low lubricity cryogenic fluids since the 1980s; some lubricants include helium, hydrogen, and oxygen. Next, pump output can be adjusted with a Variable Frequency Drive. Finally, the pumps are designed to operate effectively while under extremely low Net Positive Suction Head (npsh) conditions. Simply stated, the pump will continue to operate effectively even as fluid levels in a tank approach empty.
Liquefied Natural Gas (LNG) Powered Vehicle (Case Study)
BNI
designed and manufactured Submersible Liquefied Natural Gas (LNG) Pumps for the Metropolitan Transit
Authority of Harris County (Houston), Texas. The pumps are used to fuel LNG powered city buses.
The pumps operate at 111 K (-260° F) and have been in service since 1996. Natural gas powered vehicles
are beneficial because they significantly reduce emissions.
Propellant Densification for NASA (Case Study)
Many of today's large
rocket engines utilize Liquid Oxygen (LOX) and Liquid Hydrogen (LH2 ) as engine propellants.
Engineers at Rockwell Space Systems discovered that smaller, lighter launch vehicles can be
used when propellants are subcooled and densified. Because it costs about $10,000 USD per
pound to place a launch vehicle into low earth orbit, propellant densification results in substantial
cost savings and the ability to launch greater payloads. BNI designed and built the submersible
slush hydrogen pumps a for a prototype system. System tests at NASA's Lewis Plumbrook Field
Station yielded positive results.