with sloping plates or elements mounted stepwise

Full Title

Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping ( gas chromatography B01D15/08; destructive distillation C10B; preparation of alcoholic beverages by distillation C12H6/02) > Fractional distillation > Fractionating columns in which vapour bubbles through liquid (packing elements B01J19/30, B01J19/32) > with sloping plates or elements mounted stepwise