Distillation+Tower

Reflux is a distillation technique involving the condensation of the distilled product vapors and the return of a portion of the condensate to the distillation system from which it started.

The use of reflux is widely practiced in industries that utilize large-scale distillations columns such as petroleum refineries, petrochemical and chemical plants and natural gas processing plants. This device is a typical industrial distillation tower. Inside the column, the down-flowing reflux liquid provides cooling and condensation of the up-flowing vapors thereby increasing the efficacy of the distillation column. A reboiler at the bottom of the distillation column provides the heat needed to generate the up-flowing vapors inside the column.

Source: Anonymous. Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Distillation (accessed Nov. 14, 2011)