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The procedure for starting draft plant (fans) in a boiler is to start the ID Fan first.

Remember that the purpose of the ID Fan is so that the Furnace operates at a slight vacuum. (See Related Link: FD Fan vs ID Fan.)

Any casing or furnace leaks then allow air to leak in, rather than allowing air with pulverised fuel and fly ask to leak out.

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12y ago
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11y ago

The induced draft fan is started first to produce a negative pressure in the furnace. If the forced draft fans were started first the furnace would become pressurized and products of combustion would leak out of the casing into the boiler room.

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Q: Why induced draft fan operate first instead of a forced draft fan?
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What is the difference between induced and forced draft cooling tower?

Induced draft --- A mechanical draft tower with a fan at the discharge (at the top) which pulls air up through the tower. The fan induces hot moist air out the discharge. This produces low entering and high exiting air velocities, reducing the possibility of recirculation in which discharged air flows back into the air intake. This fan/fin arrangement is also known as draw-through. (see Image 3)Forced draft --- A mechanical draft tower with a blower type fan at the intake. The fan forces air into the tower, creating high entering and low exiting air velocities. The low exiting velocity is much more susceptible to recirculation. With the fan on the air intake, the fan is more susceptible to complications due to freezing conditions. Another disadvantage is that a forced draft design typically requires more motor horsepower than an equivalent induced draft design. The benefit of the forced draft design is its ability to work with high static pressure. Such setups can be installed in more-confined spaces and even in some indoor situations. This fan/fill geometry is also known as blow-through.


What is an induced-draft air-cooled condenser?

relies on natural convection and doesn't use a fan


What is the sequence of operations of gas furnaces?

Thermostat calls for heat. Induced draft fan motor starts. Vent pressure switch verifies pressure. Simultaneously gas valve opens and ignitor lights burner(ignition varies: hot surface ignitor, electronic spark ignitor, or standing pilot). Flame is sensed. High limit temperature switch is made. Blower fan runs. Thermostat calls for no heat. Gas valves close. Burners shut off. Induced draft fan shuts off. Blower fan put into fan delay(fan blower continues to run). Low limit temperature switch made. Fan blower stops.


Loadline Scantling draft and design draft?

what is the correct meaning of wood scantling


What is a draft in CAD?

Computer aided.

Related questions

Why induced draft fan capacity is more compare to forced draft fan in power plant?

Because it is induced


Forced draft fan vs induced draft fan?

In a balanced draft boiler, you actually have both: forced draft (FD) fans supplying air to the furnace, and induced draft (ID) fans removing flue gas. Typically, the FD fans control airflow, while ID Fans control furnace pressure to slightly below atmospheric pressure. In general though, the choice between forced draft and induced draft is based on how "tight" the system is - if you have leaks, it is better to use ID, as FD will cause product loss.


What type of air cooler is normally preferred forced draft or induced draftwhy?

the induced draft type is more expensive than the other type, however it is often preferred because it is more efficient.


Is forced draft has negative pressure drop?

No, the forced draft fan has positive pressure as it just forces yhe air into the combustion chamber.only the induced draft fan has negative pressureas it removes the flue gases & exhaust gases is stacked up


Can Forced draft fan can be used as a induced draft fan?

A forced draught is where the air flow comes directly from the fan to the object. Such as an hair dryer.An induced draught is where the air flow is induced {lit lead in} by a separate flow of air. For example, an abrasive jet would quickly wear out if the abrasive passed through the jet nozzle. the flow of abrasive is added (induced) into the air flow by a jet of clean air.If an air flow is corrosive or very dirty then an induced flow system would be appropriate.


What is a balanced draft and how is it controlled?

furnace equipped with FD(force draft) and ID(induced draft) fan /blower are called balanced draft system.Fd used to regulate combustion airflow while ID used to regulate furnace pressures type of furnace operate slightly below ATM pressure .


How induced draft fan works?

flue gas out


What is the difference between induced and forced draft cooling tower?

Induced draft --- A mechanical draft tower with a fan at the discharge (at the top) which pulls air up through the tower. The fan induces hot moist air out the discharge. This produces low entering and high exiting air velocities, reducing the possibility of recirculation in which discharged air flows back into the air intake. This fan/fin arrangement is also known as draw-through. (see Image 3)Forced draft --- A mechanical draft tower with a blower type fan at the intake. The fan forces air into the tower, creating high entering and low exiting air velocities. The low exiting velocity is much more susceptible to recirculation. With the fan on the air intake, the fan is more susceptible to complications due to freezing conditions. Another disadvantage is that a forced draft design typically requires more motor horsepower than an equivalent induced draft design. The benefit of the forced draft design is its ability to work with high static pressure. Such setups can be installed in more-confined spaces and even in some indoor situations. This fan/fill geometry is also known as blow-through.


What is the function of forced draft fan?

force draft fan is helped in producing draft. therefore, no requirement of more chimney height. with the help of forced draft we would rapidly circulated the air from boiler to chimney. this fan is mounted near the boiler bottom.


What forced men into the army in the Civil War?

The Draft.


Were us army doctors in the Korean war drafted or volunteered?

Drafted or draft induced volunteers.


What is an induced-draft air-cooled condenser?

relies on natural convection and doesn't use a fan