Studies on wetted-wall column

Gas phase mass transfer coefficients were quit useful in the design of process equipment. But the estimation of mass transfer coefficients was conventionally done with the help of wetted-wall column. Wetted-wall column is one of the simplest mass transfer systems, in which vaporization of liquids from a thin film of liquid flowing down the wall of a cylindrical tube counter currently to a stream of gas flowing through the center of the tube occurs. Liquid is introduced at the top of the circular section which serves as a weir and distributes the liquid as an even film over the wall. The liquid is removed through the seal at the bottom from the slightly flared lower end. Measurement of the rate of evaporation of a liquid into the gas stream over known surface permits calculation of mass transfer coefficient (kg) for the diffusion of vapor into gas stream.