Category Archives for Gravity Separation
Electrostatic Coalescers
Coalescing of the small water drops dispersed in the crude can be accomplished by subjecting the water-in-oil emulsion to a high-voltage electrical field. When a non-conductive liquid (oil) containing a dispersed conductive liquid (water) is subjected to an electrostatic field, … Continue reading
Coalescing Media
It is possible to use a coalescing media to promote coalescence of the water droplets. These media provide large surface area upon which water droplets can collect. The most common coalescing media is wood shavings or excelsior, which is referred … Continue reading
Water Droplet Size and Retention Time
The droplet diameter is the most important single parameter to control to aid in water settling since this term is squared in the settling equation. A small increase in diameter will create a much larger increase in settling rate. It … Continue reading
Temperature Effects
Adding heat to the incoming oil/water stream is the traditional method of separating the phases. The addition of heat reduces the viscosity of the oil phase allowing more rapid settling velocities in accordance with Equation 6-1. It also has the … Continue reading
Viscosity
Laboratory testing of a particular oil at various temperatures is the most reliable method of determining how an oil behaves. ASTM D 341 outlines a procedure where the viscosity is measured at two different temperatures and then either through a … Continue reading
Gravity Separation
Most oil-treating equipment relies on gravity to separate water droplets from the oil continuous phase, because water droplets are heavier than the volume of oil they displace. However, gravity is resisted by a drag force caused by the droplets’ downward … Continue reading