Cement factories heavily use draught fans in their boilers during the combustion process. The draft fans or draught fans as they are variously called in different countries and regions, play a critical role in the cement manufacturing process.

1. INDUCED DRAUGHT FANS AND FORCED
DRAUGHT FANS IN CEMENT FACTORIES
Neel Rao
Writes on Reitzindia Induced draft fan and Reitz India's
ID Fans and FD Fans.

2. Cement factories heavily use draught fans in their boilers during the combustion
process. The draft fans or draught fans as they are variously called in different
countries and regions, play a critical role in the cement manufacturing process.
These fans also play a very important role in another major industry i.e. in thermal
power plants where they facilitate different operations related to power generation.
In thermal plants operated by coal, several types of process fans are used. So it is no
surprise that draught fans are also used in cement factories as they need robust
process fans for handling the manufacturing process.
In the cement industry, draught fans are extensively used to mechanically facilitate
the requirement of air in the furnace. This helps in carrying out the combustion
process in the right way. In cement factories, the two main types of draught fans
used include induced draught and forced draught fans.

3. What is the function of draught fans in cement factories?
Draught fans are used in the cement manufacturing process to maintain a steady
flow of air. There are two key types of draught fans. These are forced draft and
induced draft fans. A forced draught fan compels the outside air to get into the
furnace system. On the other hand, an induced draught fan takes flue gases from the
furnace to the outer environment.
Both these types of fans are set to operate in perfect sync to balance the air system.
This enhances the efficiency of combustion in cement factories.
Some of the functions of draught fans include supplying air mixture and pulverized
coal for combustion, heating the system, regulating the combustion, and heating the
air. On the other hand, they reduce the contaminants and toxic gases around the
boiler by drawing them outside through the chimney.

4. Forced draught fans
The key function of forced draught fans is to ensure adequate air supply to the
rotatory kiln/furnace in cement factories. These fans mechanically create air
pressure in the combustion chamber. Unless the forced draught fan operating, the
pre-heating and calcination process would not happen properly. When the heat
from the furnace/rotatory kiln reaches the raw material the high temperature and
heat cause chemical changes in the finely powdered raw material causing it to form
clinkers. These clinkers are ground later to produce cement. The forced draught fans
play a key role in furnace combustion and also in ensuring the raw material is
exposed to high temperatures.

5. Induced draught fans
Induced draught fans are necessary to create negative or suction energy in the
furnace/rotary kiln in cement factories. This helps in removing flue gases from the
furnace area. So, after the combustion process, these gases find a vacuum created
by induced fans and flow out. In this process, they come in contact with the raw
materials and cause a change in the chemical composition due to the heat from the
furnace. The function of induced draught fans is to suck the air out of the kiln.
Usually, a chimney is used to discharge these gases from the kiln.
Induced draught fans regulate the pressure in the furnace/rotary kiln. This helps the
combustion process to take place effectively and it eliminates the flue gases.

6. Why are both the induced and forced draught fans needed?
Forced draught fans are needed to ensure proper combustion in the cement
manufacturing plant. This helps in maintaining the right operational environment,
leading to increased productivity. In terms of power, induced fans need more
electricity to operate compared to forced draught fans. Incorporating both these
types of fans in cement factories, it’s possible to boost productivity.

7. 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.
Thank you for spending your precious time in reading this article!