Fluidized
Bed
Combustion
Systems
-
FBC
With the escalating prices of oil and gas during the last decade, the world power industry shattered and there is a move to shift the power industry from oil to coal as coal is abundant compared with oil. With the growing realization that the low sulphur fuel oil and natural gas are not going to be available for electric generation in the near future, the power industry is slowly moving for the old faithful fuel-coa1.
Pulverised fuel firing was developed earlier this century and universally used throughout the world till today for power generation.
Pulverisation
opened
a
new
field
of
using
high
ash
coals
which
were
not
suitable
for
conventional
burning
methods
But
the
pulverised
fuel
boilers
have
some
inherent
drawbacks
as
listed
below:
A
pulverised
fuel
fired
furnace
designed
for
a
particular
type
of
coal
cannot
be
used
for
burning
any
other
type
of
coal
with
the
same
efficiency
and
safety.
The
size
of
the
coal
used
is
limited
by
the
pulverised
fuel
furnace
temperature
and
in
addition
to
this
the
coal
particle
size
is
also
governed
by
the
fuel
characteristics
like
volatile
matter,
ash
content,
etc.
The
particle
size
of
the
coal
used
in
furnaces
is
limited
to
70
-100
microns.
Therefore,
large
investment
is
needed
for
coal
preparing
equipments
and
for
its
maintenance.
The
ignition
of
the
coal
particles
becomes
easy
and
combustion
becomes
steady
when
the
temperature
in
the
furnace
is
of
the
order
of
1650°C. Considerable difficulty is experienced for maintaining stable combustion at part loads as the temperature drops. This difficulty is generally solved by using auxilary fuels like furnace oil. The present day boilers work under part load conditions for a considerable period of the day with fuel oil support burners, resulting in considerable expenses on fuel oil.
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