a fractionating column的用法和樣例：
例句
- As the solution to be purified is heated, its vapors rise to the fractionating column.
當要被提純的液體受熱時，它的蒸汽上升到分餾柱。 - Reaction is carried out under a fractionating column that allows aldehyde to pass but returns alcohol to the reaction vessel.
反應是在裝有分餾柱的反應器中進行的，分餾柱能讓醛通過但使醇迴流到反應器中。
