Fractional distillation differs from that of a simple distillation only in the fractionating column placed between the distilling pot and the still head. Within this column the plates are arranged horizontally a few centimetres apart with bubble caps above.
The ascending vapors are forced to rise through the bubble caps in each plate and then bubble through the liquid, this liquid flows from left to right on one plate, then overflows onto the plate below, and there flows from right to left. This continues until all of the greater volatile liquid has been separated from the mixture.
Distillation is utilised everyday in the laboratory and is a continuous process within industry, this is explained in more detail later.
Author: Lyndsey Booth (document modification date: 19th May 2003)