Centrifugal separation process-stream emulsions

Separation of two liquid phases, immiscible or partially miscible liquids, is a common requirement in the process industries. For example, in the unit operation of liquid-liquid extraction the liquid contacting step must be followed by a separation stage (Chapter 11, Section 11.16). It is also frequently necessary to separate small quantities of entrained water from process streams. The simplest form of equipment used to separate liquid phases is the gravity settling tank, the decanter. Various proprietary equipment is also used to promote coalescence and improve separation in difficult systems, or where emulsions are likely to form. Centrifugal separators are also used. 

The centrifugal fuel-cleaning process consists of mixing 5-10% water with the oil plus an emulsion breaker to aid the separation of water and oil. Then a mixer dispenses the wash water into the oil stream to aid the impurities in forming a water solution. The centrifuges then separate this water from the... 

To effectively monitor the separation efficiency of the particular treatment equipment, two specific methods are employed centrifugation (discussed briefly under Testing Procedures ) and the Dean-Stark analysis. The Dean-Stark analysis determines the fractional composition of oil-hydrocarbon, water, and solids of an emulsion stream by using a distillation process. Its results for heavy-oil emulsions are generally more reliable than those obtained by centrifugation however, the results of centrifugation are... 

---