Components Of An Industrial Centrifugal Fans
                     Components Of An Industrial 
Centrifugal Fans
Neel Rao
Writes on Industrial fan manufacturers & Reitzindia
 industrial fan manufacturers.
The industrial centrifugal fans are used for moving air or gases, powdery substances, 
or tiny particles in a direction at an angle to the incoming duct in manufacturing 
process plants. The air flows along the centrifugal or radial direction, therefore they 
are sometimes called radial flow type fans.
Industrial Centrifugal fans are used to provide a high-pressure flow of air for 
conveying, combustion air, cooling, exhaust, ventilation, and other uses. The 
important parts of industrial centrifugal fans are fan housing, inlet and outlet ducts, 
impellers, driveshaft, drive mechanism fan dampers and vanes, fan blades, 
couplings, bearings, isolators, hoods, flanges, guards, fan discharge casing, impeller 
locking device, and shaft seal plates. 
Fan housing enhances the efficiency of the fan by reducing noise and acting as a 
protection for moving parts like a hub, impeller, etc. In an industrial centrifugal fan, 
the stream of air gets into the impeller in an axial direction, gains acceleration due to 
centrifugal force as it flows through the fan blades, and gets released radially in 90 
degrees direction from the fan housing.
Inlet and outlet ducts will affect the airflow pattern and performance of the fans. 
Inlet ducts direct the flow of air or gas by admitting required amounts of air whereas 
resistance is imposed to the air stream by outlet ducts. Ducts with sharp-cornered 
turns result in inefficient operation of the fan.
An impeller is a rotating device consisting of several fan blades mounted on a hub 
with a drive shaft that drives the air or gas in the desired direction with increased 
pressure. For industries with large capacity plants which need high-pressure airflow, 
custom-designed impellers are used such as multistage impellers and double inlet 
impellers in which two or more impellers with a single inlet are mounted back to 
back on the same shaft.
The driveshaft is a rotating device that holds the blades and impeller. It controls the 
speed of the fan rotor through different drive mechanisms like a belt driven, direct 
driven and variable. The design of the drive shaft depends on the velocity of inlet 
gases and the weight of the installed impeller. The fan speed is directly proportional 
to the motor speed in direct driven fans because in these fans the shaft is 
straightaway connected to the motor shaft of the fan. The rotor speed is fixed in 
belt-driven fans unless the belt gets misplaced from its position because in these 
fans the motor shaft and the fan shaft are attached by the belt which is mounted on 
the sheave. Couplings are used by direct driven & variable-driven fans (using VFD), 
to get the desired variable speed by establishing a connection between the motor 
shaft and rotor shaft. Some of the industrial centrifugal fans consist of electronic 
variable speed drives that can automatically control the fan speed at the desired 
level.
The industrial centrifugal fans are robust in structure, typically drum-shaped devices 
which consist of several fan blades mounted around the hub. In the fan housing, the 
hub turns on a drive shaft. The air or gas enters into the impeller from the side of 
the fan wheel, turns 90 degrees and accelerates due to the centrifugal force as it 
flows over the fan blades and gets released from the fan housing.
About REITZINDIA
Reitz India has set a benchmark to deliver high quality fans for heavy duty industries 
which can work at precise operating conditions like high temperatures and pressures. 
Reitz offer idealistic Centrifugal Fan and Centrifugal blower design that can be used in 
all large scale process industries like cement, iron & steel, power plants, fertilizers/ 
chemicals and more.
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