A calming baffle is a particular kind of perforated plate commonly used to prevent and eliminate flow turbulences inside the treatment plants and to introduce the two-phase liquid flow in the settling compartment with a laminar flow regime, as in the picture above.

The calming process of the flow rate is very useful because it provides the best performances from the parallel plate pack located after the calming baffle: when the liquid flow enters with regular distribution and speed, the separation process can immediately start. Without a calming baffle, the liquid distribution can be very chaotic and the performance of the plate pack decreases consistently.
In some particular cases, it is possible to use a Double Calming Baffle usually made by two different calming baffles in series. This configuration significantly increases the calming effect on the flow but, on the other hand, requires more space and is more expensive.