The engineering task
A two-phase feed must be separated into gas and liquid. The gas space must remove the specified droplet size while the liquid section accommodates normal level, control span, alarm volume and possible slug volume.
Diameter and length are coupled: a larger diameter improves gas area and holdup depth but increases weight and wall thickness. Inlet momentum, foaming, entrainment, re-entrainment and nozzle locations determine whether theoretical separation is achieved in practice.
Required design data
- Gas and liquid rates at minimum, normal and maximum conditions
- Densities, viscosities, surface tension and target droplet size
- Required holdup and slug time
- Operating pressure, design cases and external piping loads
Technical solution approach
Characterise the inlet
Determine phase rates and two-phase pressure loss for all cases; treat slugs separately from steady operation.
Size gas area
Derive allowable gas velocity from droplet size, density difference and separation internals.
Allocate liquid volumes
Set low-low, normal, high and high-high levels from control, alarm and response times.
Check geometry and internals
Iterate L/D ratio, inlet calming, demister, outlet and protection against re-entrainment.
Verify vessel and supports
Calculate shell, heads, openings and saddles for pressure, self-weight, liquid weight and piping loads.
Expected deliverables
Suitable SOL ALPHA modules
The modules form a technically plausible toolchain. Their final selection and sequence will be confirmed during the later calculation against the applicable code and project conditions.