In vane-type droplet separators with a vertical gas flow the baffle vanes are arranged horizontally or at a slight angle to the horizontal. Since the gas flows upwards in the opposite direction, it is necessary for the baffle vanes to be designed so that certain regions are bypassed by the gas flow.
Thus zones are provided in which the droplets can be collected without interaction with the gas. These zones also provide a secure diversion of the collected liquid from the surface of the vanes. This requirement can be met in various ways and in function of the profile and shape of the vanes.
As the liquid has to flow in the opposite direction to the gas, the film of liquid that forms on the vane has to be converted back to droplets. To prevent overstressing of the system by droplets being picked up and recirculated by the gas flow, these droplets must be substantially larger than those carried into the separator by the gas.