Fuels and Combustion During the carbonisation of coal All of these All tar is evolved at < 600°C Evolution of H₂ and formation of methane and aromatics occur at > 700°C Hard semi-coke starts shrinking at 600°C All of these All tar is evolved at < 600°C Evolution of H₂ and formation of methane and aromatics occur at > 700°C Hard semi-coke starts shrinking at 600°C ANSWER DOWNLOAD EXAMIANS APP
Fuels and Combustion The fuel ratio of a coal is Both A and B Neither A nor B The ratio of its percentage of fixed carbon to that of volatile matter Helpful in estimation of its rank Both A and B Neither A nor B The ratio of its percentage of fixed carbon to that of volatile matter Helpful in estimation of its rank ANSWER DOWNLOAD EXAMIANS APP
Fuels and Combustion As the C/H ratio of the fuel increases, the amount of CO₂ formed on combustion __________ for the same percentage of excess air. Increases Decreases May increase or decrease depending on the type of fuel Remains same Increases Decreases May increase or decrease depending on the type of fuel Remains same ANSWER DOWNLOAD EXAMIANS APP
Fuels and Combustion A travelling grate stoker is meant for the efficient burning of __________ coal. Caking High ash Non-caking Pulverised Caking High ash Non-caking Pulverised ANSWER DOWNLOAD EXAMIANS APP
Fuels and Combustion During combustion of gaseous fuels, deficiency of air Does not affect the flame length Increases the flame temperature Tends to shorten the flame Lengthens the flame Does not affect the flame length Increases the flame temperature Tends to shorten the flame Lengthens the flame ANSWER DOWNLOAD EXAMIANS APP
Fuels and Combustion Which of the following is not applicable to fluidised bed combustion of coal? Less heat transfer surface area is required in boilers It achieves higher fuel combustion efficiency None of these It can not burn low grade coal Less heat transfer surface area is required in boilers It achieves higher fuel combustion efficiency None of these It can not burn low grade coal ANSWER DOWNLOAD EXAMIANS APP
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