FUELS AND COMBUSTION QUIZ

Which of the following is the most important deterrents to an extended use of pulverised coal in boiler firing?

Erosion of induced draft fan blades

High power consumption in its transportation

Ash disposal problem

Excessive fly-ash discharge from the stack

TRUE ANSWER : ?
YOUR ANSWER : ?

With increase in calorific value of fuels, their adiabatic flame temperatures

Remain unchanged

May increase or decrease ; depends on the quantity of products of combustion

Increase

Decrease

TRUE ANSWER : ?
YOUR ANSWER : ?

Overfire burning in a furnace is a phenomenon characterised by the

Supply of excess fuel

None of these

Burning of carbon monoxide and other incombustibles in upper zone of furnace by supplying more air

Supply of excess air

TRUE ANSWER : ?
YOUR ANSWER : ?

Octane number of 2, 2, 4 - trimethyl pen-tane is

More than 100

100

In between 0 and 100

TRUE ANSWER : ?
YOUR ANSWER : ?

Gross and net calorific value of a fuel will be the same

Ifits carbon content is very low

If its ash content is zero

Under no circumstances

If its hydrogen/hydrogen compound content is zero

TRUE ANSWER : ?
YOUR ANSWER : ?

Nitrogen present in the flue gas is determined in the orsat apparatus by absorbing it in

Ammoniacal cuprous chloride

KOH

Pyrogallol solution

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

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.

< 37%

None of these

In between 37 & 71%

>71%

TRUE ANSWER : ?
YOUR ANSWER : ?

The average molecular weight of a flue gas having the composition by volume as CO₂ = 25%, O₂ = 25%, N₂ = 50% will be

42.9

47.3

27.6

23

TRUE ANSWER : ?
YOUR ANSWER : ?

A coal containing high amount of volatile matter will have

Low adiabatic flame temperature

Very little ash content

Low ignition temperature

High fusion point of its ash

TRUE ANSWER : ?
YOUR ANSWER : ?

A coal having higher volatile matter content, has lower

Ignition temperature

Smoking tendency on burning

Coke oven gas yield on carbonisation

Chance of catching fire during storage in open space

TRUE ANSWER : ?
YOUR ANSWER : ?