Ceramic coating material for furnace refractory, which increases its emissivity and thus the radiation heat transfer rate in the furnace, comprises of_________________?

Related Mcqs:

1. Combustion of furnace oil in a furnace (soaking pit) with preheated combustion air at 400°C results in saving of about __________ percent furnace oil as compared to its combustion with atmospheric air, if the flue gas outlet temperature from the soaking pit is 1200°C ?

   A. 5
   B. 60
   C. 20
   D. 40

2. In a furnace, the heat taken by the charge/stock and the heat lost to the furnace structure & flue gases depends on the__________________?

   A. Rate of firing and emissivity of flame
   B. Thermal conductivity of the charge & structural materials of furnace
   C. Nature of process; whether batch, continuous or intermittent
   D. All A., B. and C.

3. Heat transfer rate to the stock/charge in the furnace does not depend upon the________________?

   A. Emissivity of the refractory walls
   B. Size of the furnace
   C. Use of waste heat recovery equipments
   D. Thickness of the stock

4. Heat transfer rate to the charge/stock in a furnace does not depend upon the________________?

   A. Type of fuels viz. solid, liquid or gaseous
   B. Flue gas temperature
   C. Emissivity of refractory walls
   D. Initial temperature of the charged stock

5. Rate of heat release in a furnace, which is the measure of heat intensity, is defined as_________________?

   A. kcal/hr/m3 combustion space
   B. kcal/m3 combustion space
   C. kcal/hr
   D. None of these

6. The electric furnace in which heat is produced by a combination of induced current and skin effect is called _____________ furnace?

   A. Arc
   B. Resistance
   C. Low frequency induction
   D. High frequency induction

7. An electric furnace producing heat by means of an electric arc struck between each of three electrodes and the charge is called ____________ furnace?

   A. Resistance
   B. Arc
   C. Low frequency induction
   D. None of these

8. Protective gas used in the annealing furnace for steel coil comprises of__________________?

   A. 95% N2 + 5% H2
   B. 5% H2 + 9% N2
   C. 100% CO
   D. 100% H2

9. Design of waste heat boiler for recovery of waste heat from furnace gases depends upon the_________________?

   A. Quantity & temperature of waste gas
   B. Dust concentration & nature of dust in waste gas
   C. Corrosive nature of the waste gas
   D. All A., B. and C.

10. Heat transfer takes place through a liquid medium surrounding the submerged material under heating, in case of a/an__________________?

    A. Blast furnace
    B. Steam boiler
    C. Salt bath furnace
    D. Annealing furnace