Air discharging from each fan passes first through a air preheated then through a isolating damper into the secondary air bust duct.
Forced draft fan in boiler pdf.
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.
The forced draft fan draws in the outside combustion air to mix with gas which fl ows into the pre mix burner and combusts.
Fd fan produce the positive pressure inside the system i e.
In this case the system is said to operate under induced draft.
The quantity of air admitted is usually regulated by a damper.
When air or flue gases flow under the effect of a gradually decreasing pressure below atmospheric pressure.
Forced draft fan fd fan in boilers.
When air or flue gases are maintained above atmospheric pressure.
Industrial manufacturers use burners to preheat air for boiler system efficiency using forced draft fans fd fans to push ambient air through industrial bur.
Forced draft the fan in this case delivers air to the furnace by means of ductwork.
The air heater heats the air before it enters the furnace.
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 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.
This fan takes air from the atmosphere and blows it into the furnace through air ducts.
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.
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.
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.
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.
And this requirement is compensated by a forced draft fan.
The cross over duct extends around to each side of the boiler furnace to form two secondary air to burner ducts.
8 shows a typical forced draft fan suitable for a large industrial boiler.
Forced draft fan supplies most of the combustion air.
Reaction forced draft fans with variable pitch control.
Normally it is done with the help of a forced draft fan.
Forced draft fans accommodate higher process inlet temperatures often working to push ambient air through burners to preheat air for boiler system efficiency.
To obtain plenty of clean combustion air.
