Which tray design uses bubble caps to control vapor flow?

Which tray design uses bubble caps to control vapor flow?

• A. Bubble cap tray
• B. Valve tray
• C. Sieve tray
• D. Packed tray

Answer: (A)

Bubble caps regulate how vapor passes through the liquid on a distillation tray. Each cap sits over a small opening and rises above the tray surface, so vapor must pass under the cap, enter the liquid, and form bubbles that rise through the liquid layer. This bubbling action controls the vapor flow, helping to distribute vapor more evenly across the tray and improve vapor–liquid contact, which enhances separation and stabilizes the column’s operation. Compared to other tray designs, this method provides a defined flow path and an adjustable pressure drop, whereas sieve trays rely on simple holes and valve trays use movable openings, with packed trays not using discrete trays at all.

Bubble caps regulate how vapor passes through the liquid on a distillation tray. Each cap sits over a small opening and rises above the tray surface, so vapor must pass under the cap, enter the liquid, and form bubbles that rise through the liquid layer. This bubbling action controls the vapor flow, helping to distribute vapor more evenly across the tray and improve vapor–liquid contact, which enhances separation and stabilizes the column’s operation. Compared to other tray designs, this method provides a defined flow path and an adjustable pressure drop, whereas sieve trays rely on simple holes and valve trays use movable openings, with packed trays not using discrete trays at all.