Abstract: An impure liquid is continuously distilled in a deaerated conduit arranged in a coil to present adjacent loops in heat exchange relationship. The conduit is divided by a partial partition into a distilland trough and a distillate trough, the latter being on the outside of each loop. The impure liquid is introduced into the distilland trough for flow therealong and vaporization, and the resultant vapor crosses over to the distillate trough due to centrifugal force and condensation within the distillate trough. As the vapor condenses in the distillate trough, the heat of condensation is transferred to the distilland trough of the adjacent downstream loop and to the incoming liquid flowing in a feed tube lying in the distillate trough. Spaced obstructions to vapor flow in the distillate trough and flow guide fins are employed to increase efficiency. A number of coils may be stacked to provide a multi-unit distillation system.