Bubble-cap tray design: identify the incorrect statement regarding skirt clearance, slot function, and gas distribution on cap trays.

Introduction / Context:Bubble-cap trays use risers and caps with slots to force vapor through liquid on the tray deck. Correct geometry of slot area and skirt clearance is essential to prevent weeping, dumping, or maldistribution.

Given Data / Assumptions:

• Standard bubble-cap construction with a skirt that seals over the riser.
• Typical operating ranges and fluids.
• Dimensions are stated in customary units.

Concept / Approach:Slot area provides the designed vapor exit path. Skirt clearance is small and controlled to maintain a liquid seal; if slot area is insufficient, vapor may force its way under the cap through the skirt clearance, degrading performance. Recommended clearances are on the order of fractions of an inch—not feet.

Step-by-Step Solution:Evaluate (a): “0.5″ to 1.5′ ” mixes inches and feet; 1.5 feet is far too large for skirt clearance.Confirm (b): slots indeed disperse gas into bubbles.Confirm (c): inadequate slot area can cause gas bypass under the cap skirt.Therefore (a) is the incorrect statement.

Verification / Alternative check:Design guides specify skirt clearances typically near a few millimeters to a few tenths of an inch, ensuring a proper seal.

Why Other Options Are Wrong:(b) and (c) describe correct functions and failure modes; (e) is a practical consideration but not the issue in (a). Thus (a) is the wrong statement.

Common Pitfalls:Typographical unit errors; assuming large clearances help capacity—they instead destroy sealing.

Final Answer:A recommended skirt clearance of 0.5″ to 1.5′ prevents slot plugging by residue buildup