Why is coal pulverized into dust?
The concept of burning coal that has been pulverized into a fine powder stems from the belief that if the coal is made fine enough, it will burn almost as easily and efficiently as a gas. … Under operating conditions, there is enough heat in the combustion zone to ignite all the incoming fuel.
Why is coal crushed before burning?
The concept of burning coal that has been pulverized into a fine powder stems from the belief that if the coal is made fine enough, it will burn almost as easily and efficiently as a gas. … As the coal gets crushed by the rolling action, the hot air dries it and blows the usable fine coal powder out to be used as fuel.
What are 4 types of coal?
Coal is classified into four main types, or ranks: anthracite, bituminous, subbituminous, and lignite. The ranking depends on the types and amounts of carbon the coal contains and on the amount of heat energy the coal can produce.
What is the difference between coal and coke?
Coal is a lustrous, black fossil fuel that includes impurities, generates smoke, and generates less heat than coke when burned. Coke is a dingy, black coal waste that burns hotter and cleaner. … Coke is a fuel made from mineral coal that has been calcined or dry distilled.
What is coal ash used for?
Coal ash is commonly re-used in a number of ways. For example, it is used as structural fill or fill for abandoned mines; as a top layer on unpaved roads; as an ingredient in concrete, wallboard, and in school running tracks; as an agricultural soil additive; and as “cinders” to be spread on snowy roads.
What is the formula of coal?
The chemical formula of coal is reported as: C135H96O9NS. Coal is usually taken as 85% carbon based on dry mass.
Which fuel firing system is more efficient?
Pulverized fuel firing is most modern and efficient method of boiler firing. Due to pulverization, the surface area of coal becomes much larger, and in this method air required for combustion is much less. As the quantity of required air and fuel both are less, loss of heat in this method of boiler firing is much less.
Which coal will have highest ash content Mcq?
Coking coal– the carbon content is around 43%-86%. It is a type of bituminous coal. Hence, lignite has the least carbon content which means that it has the highest ash content.
Why pulverized coal is used Mcq?
Why is pulverised coal used? … Increased calorific value of coal.