In forced circulation, the heating element is injected_________________?

Related Mcqs:

1. 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

2. The type of liquor circulation system to be ‘ employed in evaporators (viz. natural or forced circulation) is determined mainly by the ______________ of the liquid?

   A. Viscosity
   B. Density
   C. Thermal conductivity
   D. Corrosive nature

3. Forced circulation evaporators are normally used for concentrating liquids having ___________________?

   A. Scaling characteristics
   B. High viscosity
   C. Both A. & B.
   D. Neither A. nor B.

4. The radiation heat flux from a heating element at a temperature of 800°C, in a furnace maintained at 300°C is 8 kW/m2. The flux, when the element temperature is increased to 1000°C for the same furnace temperature is_____________________?

   A. 11.2 kW/m2
   B. 12.0 kW/m2
   C. 14.6 kW/m2
   D. 16.5 kW/m2

5. Circulation pump is located below the evaporator to___________________?

   A. Avoid cavitation
   B. Avoid frequent priming
   C. Create more suction head
   D. None of these

6. Heat transfer co-efficient equation for forced convection, Nu = 0.023 Re 0.8. Pr n, is not valid, if the value of __________________?

   A. n = 0.4 is used for heating
   B. n = 0.3 is used for cooling
   C. Reynolds number for the flow involved is > 10000
   D. Reynolds number for the flow involved is < 2100

7. In forced convection, the heat transfer depends on _______________?

   A. Re, Pr
   B. Re, Gr
   C. Mainly Gr
   D. Re only

8. Nusselt number (for forced convection heat transfer) is a function of the _____________ number?

   A. Prandtl
   B. Reynolds
   C. Both A. & B.
   D. Neither A. nor B.

9. Which of the following is unimportant in forced convection ?

   A. Reynolds number
   B. Prandtl number
   C. Grashoff number
   D. None of these

10. Which of the following forced convection heat transfer equation accounts for the liquid viscosity effect for viscous liquids ?

    A. Dittus-Boelter equation
    B. Sieder-Tate equation
    C. Nusselt equation
    D. None of these