Related Questions

Ceramic recuperators (made of SiC) is economical, only when used for preheating combustion air above __________ °C.
A 250
B 650
C 850
D 1000
Preheating prior to welding is done for the purpose of
A decreasing cooling rate
B facilitating fusion of high melting metals
C preventing hot cracking
D ensuring full penetration
Preheating before welding is done to
A Make the plate softer
B Burn oil & grease sticking to plate surfaces
C Avoid plate distortion
D Prevent cold cracks
The thermal efficiency of an air/fuel gas preheating recuperator may be as high as __________ percent.
A 50
B 65
C 85
D 99
Use of excess of combustion air in the combustion of fuels results in
A Heat losses
B Long flame
C Condensation of water vapour from the fuel gas
D None of these
Deficiency of combustion air during combustion of a gaseous fuel
A Lengthens the flame
B Causes heat loss of fuel by its partial combustion
C Both A & B
D Shortens the flame
Which of the following does not require preheating during storage in the storage tank as well as during atomisation through burners?
A PCM
B Tar
C Light diesel oil
D Low viscosity furnace oil
Preheating is essential in welding
A Cast iron
B High speed steel
C All nonferrous materials
D All of the above
Preheating of __________ the flame temperature.
A The gaseous fuel before combustion decreases
B Combustion air decreases
C Either the fuel or the air or both, increases
D Either the fuel or the air does not affect
Which furnace employs preheating, heating and soaking zones?
A Soaking pit
B Reheating furnace
C Open hearth furnace
D Cupola

Next steps