Page 6 - Industrial Technology EXTRA 19th July 2021

which may also need attention during
an overhaul or a retrofit project.
This can be mitigated by using laser
scanning technology and by creating a
3D CAD model of the rotor and the
casing. By combining the two, and
using cutting-edge technology, a
performance chart for the 3D model
can be generated. This can be
compared to the actual data from the
compressor itself and used to refine the
model until it is a true representation.

Today, seal improvements and efficiency Modelling improvements
upgrades through non-metallic wear parts and From this point designers can introduce
improved rotor designs can be created and improvements to the model and establish their
manufactured using state-of-the-art equipment. influence on output and efficiency. Changes in
Modern design processes and additive impeller profiles, enhancements to bearings and
manufacturing techniques can greatly reduce the labyrinth seals, can all be simulated and evaluated
lead-time for new parts. to establish to most beneficial designs.
Retrofit programs can go much further and alter Modern manufacturing and machining
the output of the asset where demand from the technologies can be applied to not only reduce lead
pump has changed over the years. By changing times, but also create more efficient components,
impeller profiles or reducing the number of stages, such as impellers with 3D vane geometry. These
the pump can be optimized for its current can all be used to improve performance and
application, often reducing the power requirements increase the mass flow rate if necessary.
and reducing running costs. The advantage of the theoretical 3D CAD is that
the suggested improvements can be trialed and
Compressors assessed for their impact on other components,
Large compressors are commonplace in the such as the intercoolers. In some cases, upgrading
chemical manufacturing sector and they often the ancillaries can be justified for the increased
operate around the clock. As such, reliability and output. Furthermore, the data can all be examined
efficiency are very important, so rigorous to enable a more informed decision.
maintenance schedules and condition monitoring
equipment are usually in place. Hot gas expanders
In many cases, compressor operators hold spare With such huge amounts of energy involved in
rotors that can be exchanged quickly, minimizing chemical manufacturing, any method of recovery
downtime and allowing more time to refurbish the needs to be properly maintained to maximize its
rotor that has been in service. benefit. The operational environment of hot gas
However, this procedure does not enable time to expanders means that they are subject to
access to the stationary section of the compressor, challenging conditions with considerable stresses

July 2021 • INDUSTRIAL TECHNOLOGY EXTRA • p6