Test method for oil mist separators

Since May 1993 the French standard NF X 44-060 describes a method of testin g oil mist separators with an air pow rate lower than 5 000 m(3) . h(-1). T he tests are designed ro qualify oil mist separators in the initial state a s well as after loading phases using aerosols produced from a mineral oil. The testing method includes both the measurement of the gravimetric and the fractional (by particle size) separation efficiency. An air filter used in general ventilation and an electrostatic air cleaner were tested according to the standard. The results show that the gravimetric method is not neces sary and can be preferably replaced by a determination using an optical cou nter in the particle size range 1 to 2 mu m for the mists produced from a m ineral oil. Concerning the mists produced from aqueous emulsions the range 0.7 to 1 mu m is proposed. These improvements could simplify the tests and thus reduce the costs.