Forced draft the fan in this case delivers air to the furnace by means of ductwork.
Forced draft fan in boiler pdf.
The forced draft fan fd fan is a fundamental part of most boiler systems and is the element responsible for creating draft inside of the boiler.
The fan then forces the resulting fl ue gases from the boiler unit and provides a positive removal of the fl ue gases from the.
The important factors to be understood in a trip of equipment in a boiler are mainly four the specific cause of trip plant response to the trip immediate operator.
Boilers have forced draft fd fans to supply air for combustion of fuel.
Forced draft fan draws the air and force it into the combustion chamber of.
Any trip of major equipment in boiler causes the boiler parameters to vary widely before it stabilizes depending upon the action taken by the operator.
In this case the system is said to operate under induced draft.
The fd fan provides the pressure and flow required to push air fuel and the resulting flue gases created from combustion through the boiler catalysts economizer fgr ductwork and stack.
The cross over duct extends around to each side of the boiler furnace to form two secondary air to burner ducts.
When air or flue gases are maintained above atmospheric pressure.
Forced draft fans accommodate higher process inlet temperatures often working to push ambient air through burners to preheat air for boiler system efficiency.
This fan takes air from the atmosphere and blows it into the furnace through air ducts.
Fd fan produce the positive pressure inside the system i e.
And this requirement is compensated by a forced draft fan.
Air discharging from each fan passes first through a air preheated then through a isolating damper into the secondary air bust duct.
Industrial manufacturers use burners to preheat air for boiler system efficiency using forced draft fans fd fans to push ambient air through industrial bur.
The forced draft fan draws in the outside combustion air to mix with gas which fl ows into the pre mix burner and combusts.
The atmospheric air is drawn into the side of the casing via a set of dampers which control the.
As we know for a steam boiler to generate steam combustion must occur be it any fuel wood coal rice husk pet coke ldo furnace oil and for combustion to exist one of its three main requirements is the air.
8 shows a typical forced draft fan suitable for a large industrial boiler.
Forced draft fan supplies most of the combustion air.
To obtain plenty of clean combustion air.
They can require less structural support and may offer a longer mechanical life than many induced draft fans because the cleaner ambient air is not as hard on the fan as the.
When air or flue gases flow under the effect of a gradually decreasing pressure below atmospheric pressure.
Reaction forced draft fans with variable pitch control.
The quantity of air admitted is usually regulated by a damper.
