Consider the following statements regarding condensation heat transfer:
1. For a single tube horizontal position is preferred over vertical position for better heat transfer
2. Heat transfer coefficient decrease if the vapour stream moves at high velocity
3. Condensation of stream on an oily surface is drop wise
4. Condensation of pure benzene vapour is always drop wise
Which of these statements are correct
Option (A)
1 and 2
Option (B)
1 and 3
2 and 4
3 and 4
Correct Option:
Question Solution:
Horizontal position promotes drop wise condensation and thickness of film formed is less. That’s why condenser tubes are always kept horizontal. Heat transfer coefficient will increases if velocity of vapour stream increased as apart from latent exchange, the sensible heat exchange will be enhanced (convection improves)