What will happen when the boiler has low combustion air pressure?
Accurate control of the amount of air is essential to boiler efficiency: Too much air will cool the furnace, and carry away useful heat. Too little air and combustion will be incomplete, unburned fuel will be carried over and smoke may be produced.
What is the purpose of the induced draft fan?
An induced draught fan (ID fan) is provided to maintain a negative pressure in the furnace by sucking the products of combustion from it with a slight positive pressure at the discharge end vis-à-vis the bottom of the chimney/stack.
What is draft loss in boiler?
[′draft ‚lȯs] (mechanical engineering) A decrease in the static pressure of a gas in a furnace or boiler due to flow resistance.
What is the significance of Draught in boiler practice what are the functions of a boiler chimney?
The draught is necessary to force air through the fuel bed/ grate to aid in proper combustion of fuel and to remove the products of combustion i.e. flue gases to the atmosphere after they have given their heat to water being evaporated in the boiler.
Why is combustion air important?
Excess air is supplied to the combustion process to ensure each fuel molecule is completely surrounded by sufficient combustion air. As a burner tune-up improves the rate at which mixing occurs, the amount of excess air required can be reduced.
What is boiler combustion?
In order for boilers to create the thermodynamic energy found in steam they must release energy from a fuel source. Combustion is the process of igniting and burning a fuel source. As the fuel source burns it releases energy in the form of heat which can then be used to transform water into steam.
What is Draught loss?
DRAUGHT LOSSES Loss due to the frictional resistance offered by flue gas passage to the flow of flue gases. Loss due to bends in gas flow circuit, which also offer flow resistance. Loss due to friction head in grate, economizer, super heater etc.
What is the difference between induced and forced draft?
Induced draft implies an inlet fan placed on top of the cooling tower and the creation of low pressure. Axial fans are always used for this type of draft. Forced draft means an exhaust fan placed at the base of the cooling tower which then causes overpressure. Both axial and centrifugal fans can be used.
What creates a draft?
Drafts are created when air passes from outside into your home, or if warm inside air exits the building structure. To form drafts, warm air needs to find a place to escape, like gaps in the window, and a difference between inside and outside atmospheric pressures.