Heat Transfer Operations Mock Test 9

10%

Question 1 of 10

1. For a fluidised bed dryer, which one of the following is correct?

Dry hot air is passed as the fluid on a bed of wet material

Wet hot air is passed as the fluid on a bed of dry material

Dry hot air is passed as the fluid on a packed bed of wet material

Hot fluid outside the tube containing particles

Question 1 of 10

Question 2 of 10

2. Consideration of multi-molecular adsorption leads to an equation given below for moisture content.

\(\frac{X}{X_1} =\frac{C\phi}{(1+k\phi)(1+(C-k)\phi)}\)

\(\frac{X}{X_1} =\frac{C\phi}{(1-k\phi)(1+(C-k)\phi)}\)

\(\frac{X}{X_1} =\frac{C\phi}{(1-k\phi)(1+(C+k)\phi)}\)

\(\frac{X}{X_1} =\frac{C\phi}{(1-k\phi)(1-(C-k)\phi)}\)

Question 2 of 10

Question 3 of 10

3. Which region represents that state when the water in the substance is available as free moisture?

Question 3 of 10

Question 4 of 10

4. What is the expression for Averaged convective heat transfer coefficient for a vertical condenser?

h_VER=0.943 \([\frac{K^3 p^2 g h_{fg}}{\mu L(T_{sat} - T_L )}]^{0.33}\)

h_VER=0.943 \([\frac{K^3 p^2 g h_{fg}}{\mu L(T_{sat} - T_L )}]^{0.35}\)

h_VER=0.943 \([\frac{K^3 p^2 g h_{fg}}{\mu L(T_{sat} - T_L )}]^{0.25}\)

h_VER=0.943 \([\frac{K^3 p^2 g h_{fg}}{\mu L(T_{sat} - T_L )}]^{25}\)

Question 4 of 10

Question 5 of 10

5. What happens in the falling rate period?

The water in the substance has completely diminished

The water in the substance is available as free moisture

The water in the substance is blocked by a membrane formed

The free moisture available on the surface shrinks to the core

Question 5 of 10

Question 6 of 10

6. The atmospheric __________ has a jacketed round pan in which a stirrer or mill revolves slowly, driven from below.

Agitated dryer

Pan - dryer

Drum dryer

Furnace dryer

Question 6 of 10

Question 7 of 10

7. The efficiency of microwave dryers is usually in the range of __________

< 70%

> 90%

> 70%

< 50%

Question 7 of 10

Question 8 of 10

8. The moisture contents of solid when it is in equilibrium with given partial pressure of vapour in gas phase is called as _____________

Total Moisture

Equilibrium moisture content

Fixed moisture

Free moisture

Question 8 of 10

Question 9 of 10

9. Dryers heated by dielectric, radiant or microwave energy are _______________

Non-Adiabatic

Isobaric

Adiabatic

Isothermal

Question 9 of 10

Question 10 of 10

10. Moisture isotherms are normally _________ in shape when plotted over the whole relative humidity range.

Parabolic

Sigmoid

Exponential

Hyperbolic

Question 10 of 10