Dust content in raw blast furnace gas is about _______________ gm/Nm3; hence it is cleaned to the dust level of about < 10 mg /Nm3 before use?
A. 15-30
B. 1-2
C. 70-100
D. 150-200
Fuels and Combustion
When steam is passed over coal resulting in the endothermic reaction represent by, C + H2O = CO + H2, it is called the _______________ of coal?
When steam is passed over coal resulting in the endothermic reaction represent by, C + H2O = CO + H2, it is called the _______________ of coal?
A. Carbonisation
B. Oxidation
C. Coalification
D. Gasification
Flue gas discharge velocity through chimney of a big thermal power plant may be around ________________ m/sec?
Flue gas discharge velocity through chimney of a big thermal power plant may be around ________________ m/sec?
A. 0.5
B. 10
C. 50
D. 500
Bomb calorimeter is used for the determination of calorific value of the _____________ fuels?
Bomb calorimeter is used for the determination of calorific value of the _____________ fuels?
A. Gaseous
B. Solid
C. Liquid
D. Both B. and C.
Coke ovens in steel plant are heated by ___________________?
Coke ovens in steel plant are heated by ___________________?
A. Electricity
B. Coke oven gas
C. Mixed gas
D. Both B. & C.
Soft coke is not ___________________?
Soft coke is not ___________________?
A. Produced by low temperature carbonisation of coal
B. A domestic fuel
C. Used in blast furnaces
D. None of these
Percentage of hydrogen in coke oven gas may be around ___________________?
Percentage of hydrogen in coke oven gas may be around ___________________?
A. 10
B. 25
C. 45
D. 60
A coal with high ash content is undesirable, as________________?
A coal with high ash content is undesirable, as________________?
A. It is abrasive to the coal pulveriser (i.e. ball mill) and the combustion chamber
B. The ash in molten condition gets absorbed in the pores of the refractory lining of the furnace
and causes its spalling due to different co-efficient of expansion/contraction of the refractory
and the ash
C. The ash retains the sulphur & phosphorus and thus affects the quality of products in
metallurgical furnace apart from increasing the slag volume. Besides, it may fuse and stick to
the boiler tubes thereby reducing the heat transfer
D. All A., B. and C.
Which of the following is the most poisonous gas ?
Which of the following is the most poisonous gas ?
A. Coke oven gas
B. Producer gas
C. Blast furnace gas
D. L.D. converter gas
Which of the following accentuates clinkering trouble on furnace grate burning coal ?
Which of the following accentuates clinkering trouble on furnace grate burning coal ?
A. Low reactivity of carbonised residue containing high proportions of iron & sulphur
B. Low forced draught and fuel bed temperature
C. Thick fire bed and preheated primary air
D. All A., B. and C.