Page 86 - Industrial Plants

Umm Lulu water
injection pumps in
Termomeccanica’s
workshop - final
assembly

treatment cycle process. without relevant pressure loss and to maintain the
A third engineering challenge was faced for the design desired efficiency.
of the crossover related to the back-to-back impeller The design of the crossover was carried out through a
configuration of the pumps. In fact, the pumps have 10 large use of CFD analysis ((see pictures - CFD
stages with the 5 impeller counter-posed to the 10 . simulation in pump crossover area 1&2)), which allowed
th
th
to detect possible complications, such as anomalous
flows, performance and pressure loss between stages
The aspect related to the reduced or pre-rotation phenomena. Based on the results of
thicknesses of the castings was such analysis, various precautions were adopted to
particularly critical given that the type of prevent the occurrence of the above-mentioned
pump water and its pressure required the detrimental behaviors: improvement of channels
use of super duplex stainless steel for the section, addition of flow rectifier in specific directions,
pressure components upgrade of the shape of deflectors and optimization of

blades and inclination angles of borders.

th
The crossover downstream the 5 stage is fed by 4
th
channels and the flow is then directed to the 6 stage Termomeccanica had to reconcile the
CFD simulation in impeller through a 7-chamber channel. mechanical features of the pressure
pump crossover It was fundamental to engineer this crossover in order components, that pushed towards
area 2 to guarantee the feeding of the downstream impellers increasing thicknesses, with the
metallurgic difficulties of super duplex
production that grow in parallel to the
increase of the material thicknesses

During the development of the project, FEM analysis
also played a key role in assisting the design of the
pumps.
For example, the Finite Element analysis was used for
the design of the shear rings to verify the stress level for
induced by the internal pressure in the test at 480 bar.
FEM analysis was also used to optimize the design of
the baseplate. Termomeccanica Pompe preferred to
supply a 3-point baseplate installed on gimbals given
that this solution, although somehow detrimental to the
project efficiency due to extra costs, weight and
complexity, allowed to overcome the difficulties created
by the unavailability of precise data for the interface

IndustrIal Plants - May 2017
84