A. Low emissivity
B. High thermal conductivity
C. Both A. and B.
D. Neither A. nor B.
Related Mcqs:
- Fuel economy in furnaces can be achieved by_________________?
A. Using oxygen enriched combustion air
B. Preheating the combustion air
C. Reducing the heat loss through furnace openings & doors
D. All A., B. and C. - Pulverised fuel fired furnaces employ ______________ fuel firing?
A. Horizontal
B. Vertical
C. Tangential
D. All A., B. and C. - Fuel economy in an industrial furnace operation cannot be achieved by the use of__________________?
A. Stoichiometric combustion air
B. Non-preheated combustion air
C. Combustion air not enriched with oxygen
D. Recuperators - Maximum heat transfer in high temperature furnaces is by____________________?
A. Conduction
B. Convection
C. Radiation
D. Either A., B. or C.; depends on the type of furnace - Hearth furnaces are not used for____________________?
A. Roasting
B. Melting
C. Reheating
D. None of these - Shaft furnaces are used for_______________________?
A. Smelting
B. Calcining
C. Roasting
D. All A., B. and C. - Thermal efficiency of furnaces can be improved by____________________?
A. Waste heat recovery from flue gas
B. Minimising heat losses from furnace walls
C. Maintaining proper draught
D. All A., B. and C. - 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. - Ingress of cold air in the furnaces through cracks, charging doors, openings etc ________________?
A. Reduces the flue gas temperature and makes the furnace atmosphere oxidising
B. Increases the load on the induced draft fan
C. Reduces the furnace draught
D. All A., B. and C. - Which of the following furnaces will have maximum thermal efficiency ?
A. Soaking pits
B. Walking beam reheating furnace
C. Boiler furnace
D. Rotary kilns
