Corrosion of pipelines is a common problem in industrial
organizations. The pipelines always contain elbow fittings.
Generally, corrosion rate in elbows is higher than corrosion rate
in straight pipes. Corrosion is governed by the flow structure
and the associated mass transfer from the flow to the elbow
wall. In this study, the mass transfer of oxygen is solved using
numerical technique. The mass transfer coefficient in elbow
relative to the mass transfer coefficient of straight pipe is
calculated and compared to published experimental data and
numerical predictions. The comparison showed that the preset
numerical technique could accurately predict the distribution of
the mass transfer coefficient in elbows. Corrosion rates are
calculated for the case study of a complex pipeline
configuration which exists is Assiut Oil Refining Company
(ASORC), Egypt. The maximum corrosion rates in different
elbows throughout the pipeline are predicted. It is found that
the maximum corrosion occurs mainly at two locations. These
locations exist at the outlet of the elbow namely at the elbow
outer surface and at the elbow inner surface. This result agree
with field observations. |
