Low temperature carbonisation
High temperature carbonisation
Medium temperature carbonisation
Heating the coal in an oven in presence of air
✅ The correct answer is option B.
Fuel and Combustion MCQs
Height of coke oven is limited (say maximum upto 7 metres) mainly by the
Problem of uniform heating along its height
Structural strength of silica bricks
Problem in door cleaning
Buckling of ram of pusher car at the time of coke pushing
✅ The correct answer is option A.
Efficiency of the combustion of a fuel is judged by the __________ the flue gas.
%of CO₂ in
% of O₂in
Temperature of
Colour of
✅ The correct answer is option B.
Preheating of coal charge for the coke ovens reduces the
Time of carbonisation
Yield of gas and tar
Fuel consumption in coking
All of the above
✅ The correct answer is option D.
Deficiency of combustion air during combustion of a gaseous fuel
Lengthens the flame
Causes heat loss of fuel by its partial combustion
Both A & B
Shortens the flame
✅ The correct answer is option C.
Which of the following has the least calorific value (kcal/Nm³) ?
Blast furnace gas
Coke oven gas
Sewage gas
Natural gas
✅ The correct answer is option A.
Which of the following is not increased by using preheated combustion air in place of ordinary air at room temperature?
Calorific value of the fuel
Flame temperature achieved
Speed of combustion of fuel
Heat transfer rate to the stock in the furnace
✅ The correct answer is option A.
With increase in calorific value of fuels, their adiabatic flame temperatures
Increase
Decrease
Remain unchanged
May increase or decrease ; depends on the quantity of products of combustion
✅ The correct answer is option D.
Stack (chimney) height in a big thermal power plant is dictated by the
Pollution control aspect
Draught to be created
Limitation of constructional facilities
None of these
✅ The correct answer is option B.
Quantity of coke oven gas produced by high temperature carbonisation of one ton of dry coal may be around __________ Nm³.
30
300
3000
30, 000
✅ The correct answer is option B.