Chemical Heat Transfer

Chemical Heat Transfer

Indirect contact heat exchangers are preferred over direct contact heat exchangers, because_________________?

Indirect contact heat exchangers are preferred over direct contact heat exchangers, because_________________?

A. Heat transfer co-efficient are high
B. There is no risk of contamination
C. There is no mist formation
D. Cost of equipment is lower

Read More Indirect contact heat exchangers are preferred over direct contact heat exchangers, because_________________?
Chemical Heat Transfer

Which of the following has the lowest overall heat transfer co-efficient ?

Which of the following has the lowest overall heat transfer co-efficient ?

A. Dowtherm
B. Molten sodium
C. Water
D. Air

Read More Which of the following has the lowest overall heat transfer co-efficient ?
Chemical Heat Transfer

Forced circulation evaporators are useful for the concentration of viscous, salting and scale forming liquors. Which of the following is a forced circulation evaporator ?

Forced circulation evaporators are useful for the concentration of viscous, salting and scale forming liquors. Which of the following is a forced circulation evaporator ?

A. Long vertical evaporator
B. Horizontal tube evaporator
C. Agitated film evaporator
D. Calandria vertical tube evaporator

Read More Forced circulation evaporators are useful for the concentration of viscous, salting and scale forming liquors. Which of the following is a forced circulation evaporator ?
Chemical Heat Transfer

The absorptivity of a grey body at a given temperature _____________ with increasing wavelength of radiation?

The absorptivity of a grey body at a given temperature _____________ with increasing wavelength of radiation?

A. Increases
B. Decreases
C. Remain constant
D. May increase or decrease; depends on the material

Read More The absorptivity of a grey body at a given temperature _____________ with increasing wavelength of radiation?
Chemical Heat Transfer

In case of heat transfer by conduction in a hollow cylinder, ______________ mean area is used to calculate the heat transfer rate?

In case of heat transfer by conduction in a hollow cylinder, ______________ mean area is used to calculate the heat transfer rate?

A. Geometric
B. Arithmetic
C. Logarithmic
D. Either A., B. or C.

Read More In case of heat transfer by conduction in a hollow cylinder, ______________ mean area is used to calculate the heat transfer rate?
Chemical Heat Transfer

The characteristic dimensionless groups for heat transfer to a fluid flowing through a pipe in laminar flow are_______________?

The characteristic dimensionless groups for heat transfer to a fluid flowing through a pipe in laminar flow are_______________?

A. Re.Gz
B. Nu, Pr
C. Nu, Pr, Re
D. Nu, Gz

Read More The characteristic dimensionless groups for heat transfer to a fluid flowing through a pipe in laminar flow are_______________?
Chemical Heat Transfer

One kilogram of water at 0°C is changed to superheated steam of one atm pressure and 300° C. The major heat consumption in the process will be to________________?

One kilogram of water at 0°C is changed to superheated steam of one atm pressure and 300° C. The major heat consumption in the process will be to________________?

A. Heat the water from 0°C to 100°C
B. Evaporate the water
C. To superheat the steam
D. Data insufficient, can’t be predicted

Read More One kilogram of water at 0°C is changed to superheated steam of one atm pressure and 300° C. The major heat consumption in the process will be to________________?
Chemical Heat Transfer

A sphere of radius ‘R1’ is enclosed in a sphere of radius ‘R2’. The view (or shape) factor for radiative heat transfer of the outer sphere with respect to the inner sphere is ________________?

A sphere of radius ‘R1’ is enclosed in a sphere of radius ‘R2’. The view (or shape) factor for radiative heat transfer of the outer sphere with respect to the inner sphere is ________________?

A. 0
B. R2/(R1+R2)
C. 1
D. (R1/R2)2

Read More A sphere of radius ‘R1’ is enclosed in a sphere of radius ‘R2’. The view (or shape) factor for radiative heat transfer of the outer sphere with respect to the inner sphere is ________________?
Chemical Heat Transfer

Corrosiveness of steam condensate is due to the presence of________________?

Corrosiveness of steam condensate is due to the presence of________________?

A. CO2
B. Dissolved O2
C. Both A. & B.
D. Neither A. nor B.

Read More Corrosiveness of steam condensate is due to the presence of________________?
Chemical Heat Transfer

Tube expansion allowances exist in _____________ heat exchanger?

Tube expansion allowances exist in _____________ heat exchanger?

A. Multipass fixed tube sheet
B. U-tube
C. Single pass fixed tube sheet
D. None of these

Read More Tube expansion allowances exist in _____________ heat exchanger?