Michael Smith Engineers has supplied
six Nikkiso canned motor pumps to
Star Refrigeration for a freeze-drying
plant for a food manufacturer. They
operate as part of the process of
manufacturing instant coffee and were
commissioned in June 2001. Since
then, half have operated almost
continuously without any servicing
or breakdown.

All six pump liquid carbon dioxide,
which is non-lubricating and has a
viscosity of around 0.1cP, at -54°
C. Four of the units pump
50m3/h at 25m differential
head; two pump 44m3/h at
35m differential head. All
operate with a hydraulic
efficiency of around 60%.

The Nikkiso BQ
Reverse Circulation pump
is mounted vertically with
the motor over the pump
ensuring quick, efficient venting of
any vapour/gas in the rotor chamber.