Exam 20: Understanding the Dominant Mechanism of Heat Transfer

The heat transfer co-efficient in film type condensation is __________ that for dropwise condensation.

"The ratio of the total emissive power to the absorptivity for all bodies is same at ther-mal equilibrium". This is __________ law.

For a liquid in laminar flow through a very long tube, when the exit fluid temperature approaches the wall temperature, the equation to be used is

For hot feed, forward feeding as compared to backward feeding results in __________ economy.

When the ratio of the Grashoff number and to the square of Reynolds number is one, the dominant mechanism of heat transfer is:

Steam economy in case of a triple effect evaporator will be

Pick out the wrong statement.

In a single evaporator system, the steam economy __________ by creating vacuum in the evaporator.

With increase in temperature, the total emissivity of conductors

The thickness of condensate layer in filmwise condensation depends on the

In sub-cooled boiling,

In case of a super-cooled solution, which is on the verge of crystallisation, the free energy of the solution as compared to that of the solid is

Which of the following parameters of the fluid is not very important, while deciding its route in a shell and tube heat exchanger?

Dittus-Boelter equation used for the determination of heat transfer co-efficient is valid

In a shell and tube heat exchanger, floating head is used for

A multiple effect evaporator as compared to a single effect evaporator of the same capacity has

Which is the best tube arrangement (in a shell and tube heat exchanger) if the fluids are clean and non-fouling?

Heat transfer by conduction results due to the transfer of free electrons, kinetic energy & vibrational energy from one molecule to another. Conduction heat transfer cannot take place

In a forward feed multiple effect evaporator unit

The units of resistance to heat transfer is