Page 19 - Industrial Technology EXTRA 20th July 2020

This led to the introduction of challenging targets for Sulzer's field service engineers removed the
energy savings that would also deliver associated pumps from the platform and delivered them to the
CO2 and NOx reductions. service center in Norway, where work started
Peter Irlam, Retrofit Specialist, Sulzer EMEA, immediately to gather all the necessary dimensional
explains: "Having worked successfully in the past data. This was transferred to the service center in
with Sulzer, the platform management called us to Leeds, UK, for the design engineers to create the
assess two pumps that had been identified for modified drawings.
rerating. Both pumps were involved in condensate For the booster pump it was decided to install
export; the main pump was a horizontal, diffuser an impeller eye choke ring to allow the pump to
barrel design, and this was supported by a operate at lower flows, thereby reducing the
centrifugal booster pump. Neither of the pumps vibration levels. The proposed design was assessed
were of Sulzer design and so there were no detailed using computational fluid dynamics (CFD) to
engineering drawings available." establish the optimum size of the choke ring.
Essentially, the issue raised by the customer was For the main pump, the proposal was to reduce
that the booster pump had some vibration issues the number of stages from seven to only two. To
because it was operating at a flow well below the maintain a smooth flow path through the sections
design point for this pump. Meanwhile, the main where the impellers had been removed, Sulzer
pump was generating too much head and as a installed transfer tubes which were designed and
result, it was consuming considerably more energy manufactured in-house. The modified design was
than was necessary. verified using rotodynamic analysis to ensure that
the pump would operate with acceptable vibration
Improved hydraulic design levels.
To help with the project design, Sulzer assessed the
production profile for the platform, projected over Achieving objectives
the next 25 years. This showed that performance Peter continues: "The customer would only allow
would be reducing year on year, so Sulzer proposed the pumps to be off the platform for a maximum of
several hydraulic changes to both the booster pump eight weeks, which left Sulzer with a tight
and the main export pump. timeframe to complete the engineering, detailed
design, manufacturing, rebuild and
installation. Through close cooperation
between our service centers, we
managed to deliver the project on time."
Having completed the installation,
the customer confirmed that the
vibration levels from the pumps were
satisfactory and the energy consumption
had been reduced by 800 kW, which
equated to a saving of more than GBP
800,000 per year, which puts the
payback in a short period of time.
www.sulzer.com

July 2020 • INDUSTRIAL TECHNOLOGY EXTRA! • p19