What is the recommended water velocity in a gravity separator?

The recommended water velocity in a gravity separator is approximately 30 cm per minute because this speed allows for effective separation of phases by providing sufficient time for the lighter materials, such as oil or gas, to rise to the top while heavier materials, such as solids or water, settle to the bottom.

At this velocity, the particles have adequate contact time to assume their respective positions within the separator based on density differences. If the velocity is too low, the separation process might become inefficient, as the lighter materials may not rise properly, leading to emulsion formation or failure to achieve a clear separation. Conversely, if the velocity is too high, it can cause turbulence that disrupts the settling process, leading to poor separation performance. Therefore, 30 cm per minute strikes a balance, ensuring effective gravity-driven separation.