A. Change in volume during a change of temperature
B. Difference in density between hot and cold gases
C. Furnace pressure in conjunction with draft in flues
D. All A., B. and C.
Related Mcqs:
- 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. - 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. - Which furnace employs an I.D. fan for the removal of flue gases from the furnace ?
A. Coke oven
B. Blast furnace stoves
C. Beehive coke oven
D. High pressure boiler - 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 - Means for giving direction to the circulation of gases in furnaces are_____________________?
A. Fans
B. Arrangement of heating stock in the furnaces
C. Location of outlet ports and heating & combustion devices
D. All A., B. and C. - The heating capacity of muffle furnace depends on the_________________?
A. Surface area & emissivity of the stock
B. Properties of the muffle wall (temperature, area, and emissivity)
C. Both A. & B.
D. Neither A. nor B. - The rate of scaling of furnace stock depends upon the_________________?
A. Temperature
B. Time
C. Nature of atmosphere
D. All A., B. and C. - An example of indirectly heated furnace is the_________________?
A. Soaking pit
B. Muffle furnace
C. Reheating furnace
D. None of these - Heat balance of furnace provides means of determining the_________________?
A. Thermal efficiency of the process
B. Sources of heat losses
C. Scope of reduction of heat losses
D. All A., B. and C. - Forced recirculation of furnace gases is practised_______________?
A. To increase heat transfer by convection
B. To ensure uniform temperature
C. In furnaces, operating below 750°C
D. All A., B. and C.
