Figure 2-31. Pipe Furnaces.
(b)
Fractionator.
The oil is then discharged into the fractionator (also
called fractionating column or distilling unit). The pressure is suddenly released
and it flashes into a mixture of vapors. Cold gasoline (gasoline reflux) is piped
into the top of the tower, cooling it and thus creating a temperature gradient:
very hot at the bottom and growing cooler closer to the top. Specific hydrocarbons
will condense out as they rise to a level with a temperature corresponding to their
They can then be piped out of the distilling unit for further
processing. The typical fractionator is a tall, steel tower filled with perforated
steel trays dividing it into sections (Figure 2-32). Gases can pass up through the
perforations and the bubble caps, but the raised rims inside the bubble caps
prevent condensed liquids from draining back down.
Figure 2-32.
Petroleum Fractionating Columns.
45 IT 0673
Previous Page
