A draught fan is a variety of industrial process fan, also called a blower, that is extensively used in factories of several sectors in the industry. These fans are among the most crucial elements in any factory/plant, and can hence be called workhorses of industrial processing plants. Draught fans can be further segregated into two sub-categories- FD (forced draught) fans and ID (induced draught) fans.

1. DRAUGHT FANS – WORKHORSES OF
INDUSTRIAL PROCESSING PLANTS
Neel Rao
Writes on Induced draft fans and forced draft fans from
Reitz india and Reitzindia industrial centrifugal process
fans.

2. A draught fan is a variety of industrial process fan, also called a blower, that is
extensively used in factories of several sectors in the industry. These fans are among
the most crucial elements in any factory/plant, and can hence be called workhorses
of industrial processing plants. Draught fans can be further segregated into two sub-
categories- FD (forced draught) fans and ID (induced draught) fans.
A forced draught fan brings in air from the external environment and pushes it inside
the system with high pressure. Likewise, an induced draught fan gathers flue gasses
that are there within the system and expels them into the outside atmosphere. Both
these variants are of equal significance in an industrial plant. It will now be
worthwhile to briefly elaborate upon some salient aspects of the subject at hand.

3. • Draught fans are of immense value in plants that are involved in generating
thermal power. In these plants, the FD fans provide the air at the required pressure
to the heating system to ensure that the process of combustion goes on smoothly.
Similarly, the ID fans, by promptly removing the flue gasses, make sure that only a
low level of contaminants is there within the combustion chamber.
The boiler’s inlet is the exact location where the FD fans are installed. And, an ID fan
is found in the middle of the chimney and dust collector.
• A forced draught fan assures that there is never a shortage of fresh air inside the
combustion chamber. With that, the right air-fuel ratio is optimally maintained, and
this is pivotal for the efficient working of the system without compromising on
safety. And, the basic functionality of ID fans mentioned above makes certain that
the flow of air gets equally spread throughout the system.

4. • A forced draught fan can be used both as a primary air fan and a secondary air fan.
Sometimes, there is a sudden requirement for extra air in the boiler for proper
completion of the process. In these situations, the air provided by the primary fan
won’t be enough. Here, the plant operates another FD fan that serves as the
secondary air fan. At this point, it needs to be mentioned that most of the plants
deploy secondary air fans only to handle contingencies; they aren’t operated
regularly.
• As forced draught fans are helpful in ensuring that the fuel gets totally combusted,
there is a marked decline in the volume of emissions. In the same way, because the
FD fans continuously supply air to the system; the boiler’s capacity gets significantly
enhanced.

5. • Both the forced draught and the induced draught fans related to a heating system
work in coordination. As a direct result of that, the process inside the system
progresses without any hassles.
• Numerous kinds of FD and ID fans are now available in the markets, to address the
varying specifications of different plants. The exact draught fan that is suitable to be
used in a given plant is dependent on the particular processes and kind of airflow
needed. Whatever the need of a unit/factory, it will have no difficulty in obtaining
the appropriate FD and ID fans.
Before draught fans are installed in a plant the management must have clarity about
the corresponding, technical aspects & requirement. It is only then that the right
blowers can be selected.

6. 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!