A fractionating column for crude oil (used in fractional distillation)
A fractionating column is a tall column that has chambers/points at different temperatures.
For distilling crude oil you would have the following:
Hydrocarbon chains have different condensing temperatures so when a 20 carbon atom hydrocarbon molecule (C20) passes through a chamber that is at its condensing temperature, it will turn from vapour into liquid (i.e. it will condense).