A. Reduces the coking time
B. Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot
oven walls
C. Increases the loss of fine coal dust from the ovens when charging
D. None of these
Related Mcqs:
- Coke oven gas produced by high temperature carbonisation of coal (as compared to that produced by low temperature carbonisation), has_________________?
A. Higher calorific value
B. Lower hydrogen content
C. Both A. and B.
D. Neither A. nor B. - In high temperature carbonisation of coal compared to low temperature carbonisation ?
A. Yield of ammonia is less
B. Aromatic content of tar is low
C. H2 content in the coke oven gas is more
D. Calorific value of the coke oven gas is lower - In low temperature carbonisation of coal as compared to high temperature carbonisation _____________ produced is less?
A. Difference in gross & net calorific value of the coke oven gas
B. Free carbon content in tar
C. Yield percentage of coke
D. Yield of ammonia present in coke oven gas - In high temperature carbonisation (as compared to low temperature carbonisation) of coal, the______________?
A. Gas yield is less
B. Tar yield is more
C. Ignition temperature of coke produced is less
D. Aromatic content of tar produced is more - In low temperature carbonisation (as compared to high temperature carbonisation) of coal__________________?
A. Ammonia yield is more
B. Aliphatic tar is produced
C. Free carbon in tar is more
D. All A., B. and C. - In high temperature carbonisation (as compared to low temperature carbonisation) of coal___________________?
A. Coke oven gas yield is more
B. Tar yield is less but free carbon in tar is more
C. Calorific value of coke oven gas is less
D. All A., B. and C. - Tar yield in the low temperature and high temperature carbonisation of dry coal may be respectively ______________ percent?
A. 3 & 10
B. 10 & 3
C. 10 & 20
D. 15 & 8 - Presence of force moisture in coal is most disadvantageous during its __________________?
A. Transportation and handling
B. Washing
C. Pulverisation
D. Storage - Yield of coke oven gas in low temperature carbonisation of coal is about ______________ Nm3 /ton of dry coal?
A. 60
B. 160
C. 500
D. 750 - Presence of free moisture in coal is most disadvantageous during_________________?
A. Its pulverisation (as it requires more power)
B. Combustion of fire slacks on the grates
C. Handling (e.g. when emptying wagons)
D. None of these
