A. Maximum to minimum heat input ratio
B. Maximum to minimum permissible gas flow rate
C. Both A. & B.
D. Minimum to maximum heat input ratio
Related Mcqs:
- Bunsen burner is an example of a/an _____________ burner?
A. Inside mixing/premix type
B. Outside mixing/diffusion flame/nozzle mix type
C. Rotary cup
D. Submerged combustion - Explosion limit of blast furnace gas is 37 to 71% gas in gas-air mixture. It means that the blast furnace gas will explode when burnt in a confined space, if its concentration in the gas-air mixture is _______________ percent?
A. 71%
C. In between 37 & 71%
D. None of these - Atomising steam to fuel oil ratio in a burner should be around__________________?
A. 0.5
B. 1.5
C. 2.5
D. 3.5 - Correct viscosity of furnace oil at the burner tip for proper atomisation is about 25 centistokes. To reduce the viscosity of high viscosity furnace oil (250 centistokes) to the correct atomisation viscosity (i.e. 25 cst), it should be preheated to about ______________°C?
A. 70
B. 85
C. 105
D. 145 - The main function of primary air in pulverised coal fired burner is to_________________?
A. Burn CO to CO2
B. Dry and transport the coal
C. Have proper combustion by supplying it around the burner
D. Preheat the tertiary air used for complete combustion of CO to CO2 - Temperature of preheated air used for the transportation of pulverised coal through pipes to the burner of a boiler furnace is restricted to a maximum limit of about 300° C to avoid the___________________?
A. Requirement of large volume combustion chamber
B. Risk of explosion
C. Chances of clinker formation
D. Incomplete combustion of coal - The gas which contributes maximum to the heating value of natural gas is __________________?
A. CO
B. CO2
C. H2
D. CH4 - Gross calorific value will be equal to the net calorific value for __________________?
A. H2
B. C2H2
C. CO
D. C2H6 - Pure carbon is completely burnt in oxygen. The flue gas analysis is 70%CO2, 20%CO and 10%O2. The percent excess oxygen used is __________________?
A. 20
B. 12.5
C. 0
D. 10 - Fuel gases containing hydrocarbons (e.g. coke oven gas) are not preheated before burning, mainly because __________________?
A. The hydrocarbons crack thereby choking and fouling the heat transfer surface by carbon soot
B. It reduces its calorific value tremendously
C. It reduces its flame temperature tremendously
D. There are chances of explosion during preheating
