Steel in industries is manufactured in two ways, traditionally by using raw materials like iron ore, coal and limestone in blast furnace or by recycling the material using electric arc furnaces.

1. Process Fans in Iron and Steel
Industry
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2. Steel in industries is manufactured in two ways, traditionally by using raw
materials like iron ore, coal and limestone in blast furnace or by recycling the
material using electric arc furnaces. The first process involves making of molten
iron using the raw materials iron ore, coke (pure form of carbon obtained by
heating and driving off impurities of coal) and lime in blast furnace. Then it is
further followed by combining varying amounts of steel scrap with molten iron
in Basic Oxygen Furnace (BOS). The second method requires no raw materials
and reuses the existing steel scrap to produce steel in an Electric arc furnace.
Both these production processes require several centrifugal fans for drying &
heating ore pellets, handling the undersized dust particles, removing and
cleaning waste gases, providing combustion air to burn coke, exhausting waste
by-products, cooling the product to remove heat etc.

3. Pelletizing Fans
Pelletizing is a process that involves mixing very finely ground particles of iron ore
fines of size less than 200mesh with additives like bentonite and then shaping
them in to oval/spherical lumps of 8-16mm in diameter by a pelletizer and
hardening the balls by firing with a fuel. It is the process of converting iron ore
fines into “uniformed sized iron ore pellets” that can be charged directly into a
blast furnace. The process of pelletization requires several industrial centrifugal
fans to supply process air for drying, preheating, indurating and cooling.
Particularly, the fans used here should be capable of handling both low level and
high level heat produced during the process. For instance, if we consider
indurating section where the pellets get dried and heated for hardening,
centrifugal fans used in the process have to handle air of different temperatures
in updraft drying zone to remove moisture from the pellet bed and to supply
downdraft drying air for heating up the pellets.

4. Sinter Plant Fans
The process of sintering is basically a pre-treatment process step during iron making
to produce charge material called sinter for the blast furnace from iron ore fines and
also from metallurgical wastes (collected dusts, sludge and mill scale etc.).The
principle of sintering involves the heating of iron ore fines along with flux and coke
fines or coal to produce a semi-molten mass that solidifies into porous pieces of
sinter with the size and strength characteristics necessary for feeding into the blast
furnace. It is basically an agglomeration process achieved through combustion.
Sintering plants use several centrifugal fan types like forced draught combustion air
fans to support the combustion, induced draught waste gas fans to draw the gases
off through dust removal system, cooling fans to cool the hot sintered product, hot
air fans to recover heat from the hot sintered product and return it to the process,
and several other fans for exhaust and dedusting.

5. Basic Oxygen Furnace Fans
Basic oxygen process is one of the main processes in steel making where pure
oxygen is supplied to the blast furnace iron and scrap of steel to produce crude
steel. Before charging the iron to blast furnace converter, pretreatment of the
metal is done to reduce sulphur, silicon and phosphorous. As the reaction takes
place, the process also produces large amount of gas (called converter gas) at high
temperatures containing mixture of combustible waste gases of carbon monoxide
(CO), carbon dioxide (CO2) and nitrogen (N2).To avoid pollution and keep the
production environment clean, there is a need to remove dust & waste gases by
drawing them through a dust removal system or wet scrubber. Here the
mechanism of induced draft air is typically used for waste gas exhaust. Also the gas
coming out of the converter is normally of high temperatures and requires cooling
using cooler exhaust fans before the gas is sent to dry precipitators. The cooler
exhaust fans are primarily used to maintain the thermal balance of the furnace.

6. Electric Arc Furnace (EAF) Fans
This is secondary method in steel making where high current electric arcs are used to
melt the steel scrap to produce steel. Oxygen and coal powder are injected into the hot
liquid metal to accelerate the formation of slag. Due to the high content of impurities
in the metal scrap, the dust generated during the process can contain hazardous waste
which can be dangerous to working environment. The particles of EAF fume extraction
can contain emissions of vapors, fine dust and solid particles. Also there is another
potential issue for larger industrial installations. Since the process is dependent on high
power electric arcs, the temperatures are relatively high near the furnace and within
the manufacturing unit. So there is a need to regulate the temperatures and keep the
work atmosphere safe. To control the volume and temperatures of waste gases and
maintain ambience in the working environment, centrifugal fans of different types are
employed for cooling and waste gas reduction.
Apart from the above fan equipment, other centrifugal fan types such as coke oven
fans, combustion air fans, booster and exhauster fans and several others are used in
steel making applications.

7. About REITZINDIA
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