A Very effective method to reduce flow turbulence is by installing a liquid distribution baffle.
This is a perforated plate designed with a certain open area to suit the given process conditions and vessel lay-out.
In order to achieve an efficient gas/liquid and liquid/liquid separation in horizontal vessels it is important to have a quiescent flow regime along the length of the vessel. Otherwise fluids can shortcut through the vessel and the actual residence time for separation will be much shorter than with a perfect distributed flow. A quiescent flow regime is achieved through the use of perforated baffles. It has been demonstrated in tests and CFD models and, more importantly, in the field that without these internals the separation process can be adversely affected.
Perforated Distribution Baffles are fitted downstream of the inlet device in the separator. The bulk liquids from the inlet device fall under gravity into the inlet processing zone, which is bounded by the Perforated Distribution Baffle. Intended to distribute the liquid flow evenly over the cross-section, prior to entry into the liquid/liquid separation region, this baffle plays an important role in maximizing the liquid/liquid separation.
In most designs, the baffle will occupy the whole cross-sectional area of the vessel. This provides some control of the gas distribution through the separator stages, helping to minimize mal-distribution effects on the downstream demisting equipment and maximizing the efficiency of the gas/liquid separation process.
A Double Perforated Distribution Baffle assembly is often fitted downstream of the inlet device in a three-phase separator (or, sometimes, in a two-phase liquid/liquid separator). In contrast, only a Single Perforated Distribution Baffle will normally be required in a two-phase (gas/liquid) separator.
Advantages of Perforated Distribution Baffles:
- Distribute and calm the fluids
- Handle slugs and surges
- Enhance interface level control
- Provide minimal pressure drop
- Enhance gas distribution on any downstream equipment
- Reduce or eliminate re-entrainment of liquid from the liquid surface
- Increase gas/liquid separation efficiency
- Enhance liquid distribution on downstream equipment
- Reduce turbulence and re-circulation within the liquid section, promoting gravity separation
- Increase liquid / liquid separation efficiency
- Wide operational range - typically, providing 100% turndown
- Easy to install in both new and existing separators
- No moving parts, so no maintenance (for clean duties)
- Reduce surface waves and sloshing effects.
