The thickness of the condensate film during filmwise condensation is governed by the__________________?
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Answer: D. All A., B. and C.
Explanation
Filmwise condensation film thickness depends on the rate at which vapor condenses onto surfaces. Surface configuration and geometry dictate how condensate drains downward under gravity forces. Liquid flow rate from the surface balances incoming condensation to establish steady film thickness. Filmwise condensation forms a continuous liquid blanket sliding down vertical or inclined walls. Nusselt's analytical theory of film condensation incorporates gravity, viscosity, and thermal conductivity. Thicker condensate films act as thermal insulators that reduce overall heat transfer performance.
Power plant steam surface condensers operate under filmwise condensation conditions on tubes. Designing efficient condensers requires minimizing condensate film thickness to maximize heat transfer. Vertical tube arrangements facilitate faster condensate drainage compared to horizontal bundles. Condensation rate alone only determines fluid addition, but drainage and geometry also govern thickness. Surface configuration alone ignores the ongoing mass addition from active vapor condensation rates. Liquid flow rate from the surface is just one factor alongside condensation rate and geometry.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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