many process applications in the petrochemical
industry, so reliability of
these towers is crucial. In many
cases, redundant towers need to be installed to
ensure that a process will not have to be stopped
due to a cooling tower failure. The most prevalent
cause of cooling tower downtime is failure of the
right-angle gearbox or associated mechanical components,
such as the driveshaft
or disc couplings.
The elimination of these
components can reduce the
losses in the drive system and offer the possibility
for improved overall system efficiency. This article
describes new developments in motor technology
that allow for the replacement of high-speed
motors, driveshafts, couplings, and gearboxes
with a slow-speed permanent magnet (PM) motor.
A case study is presented with provisions of maintenance
and efficiency improvement data.