What is the use of draft fan in thermal power system?

What is the use of draft fan in thermal power system?

Forced Draft Fans (FD) supply the air necessary for fuel combustion by pushing air through the combustion air supply system and into furnace. These fans are located at the inlet of boiler to push high pressure fresh air into combustion chamber, where it mixes with the fuel to produce positive pressure.

What is induced Draught 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.

How does induced draft fan work?

An induced-draft burner uses a blower to pull air into the burner, and through the combustion chamber and heat exchanger. The fan then pushes the flue gases out through the vent. This creates negative pressure in the furnace, and may create positive or negative pressure in the venting systems.

What is the function of forced draft fan FDF in a thermal plant?

In coal fired power plants, forced draft fans (FDF) are usually used to supply combustion air into boiler [1]. The FDF has an important role to provide the effective combustion in various conditions and produce better heat transfer by circulating gases.

What is Draught fan?

Draught fans are a type of industrial process fans and are broadly divided into two types – Forced Draft (FD Fan) and Induced Draft (ID Fan). Both FD fan & ID fan operate in such a way that it balances the air system in the thermal plant to make the combustion process efficient.

What is induced draft and forced draft fan?

Comparing Forced Draft Versus Induced Draft Forced-draft fans focus the pressure and volume at the outlet of the fan to push air through a system, creating positive air pressure. Industrial induced draft fans operate by focusing the pressure and volume at the inlet of the fan to pull air through a system.

What is Draught in thermal power plant?

7.1 INTRODUCTION TO DRAUGHT SYSTEM Boiler draught is the pressure difference required to maintain constant flow of air into the furnace and to discharge the flue gases to the atmosphere through a chimney. Thus, boiler draught is one of the most essential systems of a thermal plant.

What is the position of fan in induced Draught cooling tower?

In Induced draft tower, the fan is placed at the top and above the eliminator such that atmospheric air is circulated from the top to the bottom. However in Forced draft tower, the fan is placed outside the tower and at the bottom such that atmospheric air is circulated from the bottom to the top.

What is the difference between forced Draught and induced Draught?

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.

Where fan is located in the forced Draught system used for thermal power plant?

Explanation: In force draught system an air blower is installed near the boiler which blows into the furnace.

How does induced Draught differ from forced Draught?

What are the various methods of obtaining Draught control?

ii) Draught produced is very low. 1) Easy control on combustion of fuel and evaporation of water….

• Fan or blower is placed before grate or situated within the oil burner assembly in case of oil fired boiler.
• Pressure inside the flue passages is slightly more than atmospheric pressure.

How are fans used in a thermal power plant?

Fans in thermal power plants. 8. Draft Fans Draft fans are generally responsible for maintaining the flow of gases through the boiler. A balanced draft system uses both a forced draft fan at the inlet of the system and an induced draft fan at the outlet of the boiler system.

Why are draught fans used in power plants?

The most common configuration of the draught fans used as a PA fan is the backward curved centrifugal fan. In power plants the PA fans play an important role in supplying air necessary for fuel combustion and in the maintenance of furnace temperature.

What’s the difference between a draught fan and an ID fan?

Draught fans are a type of industrial process fans and are broadly divided into two types – Forced Draft (FD Fan) and Induced Draft (ID Fan). The primary difference between a forced draft and induced draft is, FD fan forces outside air into the heating system whereas ID fan draws flue gases from the system out into the atmosphere.

Where is the induced draft fan located in a boiler?

Induced draft fan is normally located at the outlet between dust collector and chimney. The fan takes hot flue gases from the boiler through dust collector and delivers it to the chimney into the open atmosphere. ID fan creates negative pressure or suction to discharge the gases out after combustion from the furnace.