in a new process of separating high concentrations of gaseous contaminants like water vapor, CO2 and H2S from well gas streams, the contaminants are condensed and subsequently removed in a centrifugal separator. This paper presents an analytical model for the formation of a thin liquid film inside the small channels of a vertically oriented rotating phase separator. Film behavior is investigated under the combined influence of centrifugal and gravitational forces. At high gas throughput the shear forces at the interface between the gas flow and the liquid film, and the resulting pressure drop over the channel, are considered as well. The gas velocity through the channels is corrected for the displacement effect of the liquid film. Solutions are presented for several channel heights at various operating conditions, and for gas flow in upward and downward direction. (C) 2008 Elsevier Ltd. All rights reserved.