Page 56 - Industrial Plants

Figure 4 -
Flow Distribution

to limit the total equipment length within the equipment performance. In addition, CFD
maximum permitted. analysis enables a deeper understanding of the
7. A balance line will be carefully designed behaviour of some sections of the separator
between liquid and gas outlet headers to allow subject to unusual flow conditions, e.g. liquid
installation of liquid level instrumentation. and gas phases that move and accelerate in
8. In the case of solid presence in the feed, opposite directions.
special features can be provided for de-sanding, CFD analysis allows for the evaluation of liquid/
cleaning and maintenance of the liquid outlet gas separation efficiency by predicting the path
header. of liquid droplets entrained in the gas phase.
Figure 1 shows an example of such a verification:
CFD simulation calculates the path of 150-micron
CFD simulation is the state-of- droplets as a function of gas and liquid density
the-art tool for the design and viscosity. CFD calculations may also be
correlated with a broad set of operating
of finger-type slug catchers parameters and therefore they may be employed
for generating sensitivity studies. Figure 2 and
The hydraulics of finger-type slug catchers is Figure 3 show the separation length calculated
extremely complex because it involves by CFD simulation for water and hydrocarbon
multiphase flow in transient conditions. Simplified droplets of 150 microns in size. Therefore,
approaches generally introduce approximations separation performances can be accurately
that do not allow a reliable estimation of calculated, thus reducing the degree of

Oiltech Expertise

Over the last 15 years, OILTECH has been in charge of the design of around 30 finger-type slug
catchers, with more than 10 reaching the construction phase and then successfully put into
operation.
OILTECH is highly experienced in dealing with different types of equipment: one-level and two-
level equipment, two-phase and three-phase separation, with and without secondary bottles.
OILTECH has developed the basic design for all these projects. With regard to other areas of
expertise, OILTECH has taken care of detailed engineering, including mechanical design, stress
analysis, vibration studies, piping design steel structures, instrumentation and project
coordination.
The CFD simulation samples that are described herein refer to the executive design of a Slug-
catcher wich was recently completed and wich is currently under construction.

IndustrIal Plants - September 2021
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