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to the emulsion. Demulsifiers destroy protective films on the drops
of water. The only (universal) demulsifier does not exist. Each
emulsion has to be researched and the corresponding reagent
(demulsifier) for it and its optimum quantity are chosen. The

neutralized black contact (got during oil refinery); vegetable oils
(sunflower, castor oil); turpentines; sulphonated phenols treated with
strong sulphuric acid; naphthenate of aluminium and others are used

as demulsifiers.
4. Electric method. It consists in the following: emulsion is let
pass in the special installations between electrodes. The current of
high voltage and certain frequency is supplied to the electrodes

(emulsion is destroyed by the current). The best results are got by
combining electric and chemical methods or chemical and thermal
methods. After destruction of emulsion the process of settling and

water removing is conducted.
5. Mechanical method. According to this method emulsion is
placed into a centrifuge and under centrifugal forces growing

exceedingly water is thrown aside to periphery. The bigger is the
difference between densities of oil and water and the more rapid
rotation of the shaft of centrifuge is, then the destruction of emulsion

is more successful.
6. Combined method. It is a combination of two or three
methods enumerated above. For example, combination of electric and
chemical methods, mechanical and thermal methods, chemical and

thermal ones, mechanical, thermal and gravitational methods and
others.
Centrifugation is one of the methods of separation of

heterogeneous systems – emulsions (for example, a liquid – liquid, a
liquid – solid particles) in rotors by using centrifugal forces.
Centrifugation is conducted in the special apparatus – centrifuges.
The main part of centrifuge is the rotor which revolves with high

velocity.
The main characteristic of the centrifuge is a separation factor. It
equals to the ratio of acceleration of the centrifugal field which is in

the centrifuge to the acceleration of gravitational force. The
separation factor is a dimensionless characteristic. Separating process
of the centrifuge grows proportionally to the separation factor.

The separation factor of centrifuges with an electric drive

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