FIELD OF THE INVENTION
The present invention generally relates to fluidized bed coal gasification systems.
More particularly, the present invention relates to a split fixture-support device
for easy erection, repair and maintenance of barrier filter candle assembly at
elevated position in pressurized fluidized bed gasification system.
BACKGROUND OF THE INVENTION
In order to meet the stringent pollution control norms and to address the
depletion of coal reserves, the gasification technology is adapted for producing
power in combined cycle using syngas as one of the resources. The syngas is
generated by feeding coal in the gasifier with air and steam as supplements
under reduced conditions. During the process chemical reaction between the coal
particles and the air/mixture of air and steam produces a stream of highpressure
and high temperature raw synthesis gas known as "Syngas" having
specific chemical composition and calorific value based on the coal composition
and the proportion of the air/mixture of air and steam used in the process. The
hot combustion gas that is produced in the gasifier is supplied to the combustor
of a gas turbine engine, which powers a generator that supplies electrical power
to a power grid. The exhaust from the gas turbine engine is admitted to a heat
recovery steam generator that generates steam for driving a steam turbine. The
power generated by the steam turbine drives an electrical generator that
prOVideselectrical power to the power grid. Thus, the electrical power produced
from both the Gas turbine - Generator and the steam turbine - Generator is fed
into the power grid.
The Integrated Gasification Combined Cycle (IGCC) is a known technology where
syngas is produced in a reactor by the chemical reaction of carbonaceous
materials at elevated temperatures at reduced atmosphere The syngas carries
fine particles called 'fly ash' which is removed to increase the gas quality of gas
turbine, before using it in a combustor of the gas turbine. In order to remove the
fly ash, various equipment are used like, mechanical cyclones, barrier filter
system, quench column etc.
During gasification process, by the process of partial combustion of crushed coal,
the mineral matter in the coal, splits into two streams namely "Bottom ash" and
"Fly ash". The heavier ash formed in the bottom of the distributor is called
"Bottom ash" and is extracted through a plurality of pipes located at various
points of the distributor, the extraction helping in maintaining the bed height and
ensuring proper fluidization. The lightweight particles and the unburnt carbon
particles called "fly ash" formed are carried away by the stream of syn gas and
passed through a group of cyclones arranged in series at high pressure and
temperature, thereby separating the fly ash from the synthesis (syn) gas, which
is, cooled in a plurality of ash coolers, depressurized, purged of toxic gases,
collected in a fly ash hopper, and converted to a form for easy disposal. The hot
coal gas at the exit of the last cyclone is cooled in a Heat Recovery Boiler (HRB)
where it exchanges its specific heat to water and contributes in steam
generation. Then the gas is further cooled in a heat recovery unit to super heat
the steam. Part of the steam is utilized for gasification process and the rest
expands in the steam turbine to generate electricity.
Then the gas is further processed in a gas cleaning system, where the remaining
fly ash, from the syngas is removed in equipment for example, barrier filter,
quench column, and mechanical cyclones etc. Finally, the cleaned syngas is
admitted to a combustion chamber of a gas turbine to generate electricity.
Among all the gas cleaning equipment, the barrier filter plays a major role in
removal of dust namely fly ash when the hot syngas passes through it. The
barrier filter system generally comprising; a cylindrical pressure vessel with a
dished end at top and a conical hopper at bottom for ash collection and disposal;
a cluster of dust removing candle filter assembly fixed in tube sheet mounted at
top of the pressure vessel with supports having provisions for nitrogen purging;
and syngas inlet and outlet connections to remove the dust from the hot syngas
stream. While the hot syngas is admitted to the dust removing candle filter
assembly, the dust particles particularly the dry fly ash sticks to the outer
membrane of the candles, allowing the clean gas to pass through the porous
candle filters. Nitrogen purging is periodically made in reverse direction to
remove the accumulated dust particles on the candle filters and collected at the
bottom of the filter vessel and disposed periodically.
Over a period of time the life of the candles filters depreciates and develops
cracks or breaking of filter candles. Sometimes the formation of wet dust sticks
over the candles leads to choking of the barrier filter which triggers the need for
repair and maintenance, which involves opening of the top dished end cover;
removing the precision candle filter assembly from the vessel and keeping it in a
safe place; dismantling of failed candle elemehts, replacing with new candles,
put back into the vessel; closing of top cover and keep it ready for operation. It
is cumbersome, to lower and lay-down the filter system at ground
floor for repair and maintenance and put back in its original position, which
ultimately leads to more cost and time.
The major problem faced during the dismantling of the barrier filter system
which is erected positioned at higher elevation, where the height between the
two floors, generally termed as 'head-spacejhead-room' is less for keeping the
candle filter assembly with tube sheet in the same floor for repair and
maintenance. Consequently to facilitate easy and safe movement of the
operators and various equipment to carry out the repair and maintenance work,
there is a need to propose a method and an apparatus to overcome the
problemsdescribedabove.
OBJECTS OF THE INVENTION
It is therefore, an object of the present invention to propose a split fixturesupport
device for easy erection, repair and maintenance of barrier filter candle
assembly at elevated position in pressurized fluidized bed gasification system,
which provides a split supporting system for candle filter assembly of the barrier
filter system during erection, repair and maintenanceperiod.
Another object of the present invention is to propose a split fixture-support
device for easy erection, repair and maintenanceof barrier filter candle assembly
at elevated position in pressurized fluidized bed gasification system, which
provides easy access for the workmen and the component for repair and
maintenancethere by reducing the cost and work time.
A still another object of the present invention is to propose a split fixture-support
device for easy erection, repair and maintenance of barrier filter candle assembly
at elevated position in pressurized fluidized bed gasification system, which
prevents any damage to the precision barrier filter candle assembly, by providing
easy access for the workmen and the component during repair and maintenance
period.
A further object of the present invention is to propose a split fixture-support
device for easy erection, repair and maintenance of barrier filter candle assembly
at elevated position in pressurized fluidized bed gasification system, which is low
head room is available for the frequent movement of heavier cylindrical
components during erection, repair and maintenance.
SUMMARY OF THE INVENTION
Accordingly, there is provided A split fixture-support device for easy erection,
repair and maintenance of barrier filter candle assembly at elevated position in
pressurized fluidized bed gasification system, comprising a first major component
and a second major component, wherein the first and second major components
each comprises at least a plurality of support plates (13,28) and a plurality of
flanges (06,21), wherein the candle filter assembly (15) is disposed above said
support plate (13) of the first major component, wherein the second major
component is movable towards the first major component such that the candle
filter assembly rests on said support plates (13,28), and wherein the major
components are rigidly fixed with said flanges (06,21) by fastening means to
form the support device.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Shows elevational, plan and end view of a split fixture-support
device for easy erection, repair and maintenance of barrier filter
candle assembly at elevated position in pressurized fluidized bed
gasification system, in assembled condition according to the
invention.
Shows elevational, plan and end view of the first major component
of the device of figure 1.
Shows the elevation, plan and end view of the second major
component of the device of figure 1.
Shows an isometric view of the device of figure 1.
Shows an alternative embodiment of the device of figure 1.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
PRESENT INVENTION
Figures 1 and 4 - Show the complete assembly views of elevation, plan and end
view of a split fixture-support device for easy erection, repair and maintenance of
barrier filter candle assembly at elevated position in pressurized fluidized bed
gasification system. The device comprising a first major component and a second
major component. The first major component comprising; a plurality of first boxchannel
(01) formed by joining a plurality of 'c' channels by stitch welding, the
channels acting as strong horizontal supporting base structure for the support
device; a plurality of second box-channel (02) formed by joining a plurality of 'C'
channel by stitch welding, and positioned vertically and welded to the first boxchannels
(01) at spaced apart locations; a plurality of third box-channel (03)
formed by joining a plurality of 'C' channel by stitch welding, and positioned
horizontally and welded to the top of the first box-channel (01) and second boxchannel
(02); a plurality of fourth box-channel (04) formed by joining a plurality
of 'c' channel by stitch welding, and positioned vertically and welded to the first
box-channels (01) and third box-channels (03) to provide strong vertical support
to the split fixture support device; a plurality of structural angles (05) positioned
horizontally and welded to the third box channel (03) to provide extra support to
the device; a plurality of plain plate flanges (06) positioned vertically and welded
at the free ends the third box-channel (03), to attach/detach the first and second
components; a fifth box-channel (07) formed by joining a plurality of 'C' channels
by stitch welding, and positioned between two of said plurality of second boxchannel
(02) at top and welded to act as strut member; a plurality of rectangular
shaped first support plates (08) positioned horizontally and welded at top of the
second box-channel (02) to bear the load and transfer it to the second box
channels (02); a plurality of trapezium shaped first stiffener plates (09)
positioned between the second box-channels (02) and support plates (08) and
welded; a plurality of rectangular shaped bracings (10) positioned below the first
stiffener plates (09) and welded; a plurality of 'L' shaped second support plates
(11) positioned vertically above the first support plates (08) and welded to bear
the load and transfer to the second box-channels (02); a plurality of rectangular
shaped second stiffener plates (12) positioned vertically at both sides of the 'L'
shaped second support plates (11) and welded; a plurality of machined stainless
steel circular shaped third support plates (13) positioned horizontally above the
'L' shaped second support plates (11) and the rectangular shaped second
stiffener plates (12) and welded to hold a candle filter assembly (15); a plurality
of square shaped dummy plates (14) welded at the open ends of the first box
channels (01) and the second box channels (02) to prevent the unwanted
materials to get inside the box channels; the second major component
comprising; a plurality of sixth-channels (16) formed by joining a plurality of 'C'
channels by stitch welding and acting as a horizontal supporting base for the
entire fixture support device; a plurality of seventh box-channels(17) formed by
joining a plurality of 'C' channel structure by stitch welding and positioned
vertically and welded to the sixth box-channels (16) to bear the load from the
device; a plurality of eighth box-channels(18) formed by joining a plurality of 'C'
channels by stitch welding, and positioned horizontally and welded at the top of
the sixth box-channel (16) and seventh box-channel (17); a plurality of ninth
box-channel (19) formed by joining a plurality of 'C' channels by stitch welding,
and positioned vertically and welded to the sixth box-channels (16) and eighth
box-channels (18) to provide vertical support to the device; a plurality of
structural angles (20) positioned horizontally and welded to the eighth boxchannels
(18) to provide extra support to the device; a plurality of plain plate
flanges (21) positioned vertically and welded at the free ends of the eighth boxchannels
(18), to attach/detach the first and second components; a tenth boxchannel
(22) formed by joining a plurality of 'C' channels by stitch welding, and
positioned between two seventh box-channels (17) and welded to act as strut
member; a plurality of rectangular shaped fourth support plates (23) positioned
horizontally and welded at top of the seventh box-channels(17) to bear the load
and transfer it to the seventh box-channels(17); a plurality of trapezium shaped
third stiffener plates (24) positioned between the seventh box-channels(17) and
the fourth support plates (23) and welded to strengthen the split fixture-support
device; a plurality of rectangular shaped bracings (25) positioned below the third
stiffener plates (24) and welded to strengthen the device; a plurality of 'L'
shaped fifth support plates (26) positioned vertically above the fourth support
plates (23) and welded to bear the load and transfer to the seventh box.
channels (17); a plurality of rectangular shaped fourth stiffener plates (27)
positionedvertically at both sidesof the 'L' shapedfourth support plates (23) and
welded to further strengthen the device; a plurality of stainless steel circular
shaped sixth support plates (28) machined at top, positioned horizontally above
the 'L' shaped fifth support plates (26) and the rectangular shaped fourth
stiffener plates (27) and welded to hold the candle filter assembly (15); a
plurality of square shaped dummy plates (29) welded at the open ends of the
sixth box-channels(16) and seventh box channels(17) to prevent the unwanted
materialsto get inside the box channels.
Accordingto the invention, after placing/resting the barrier filter candle assembly
(15) above the stainless steel circular shapedthird support plate (13) by moving
sideways using a hoisting arrangement (not shown) on the first component, the
secondcomponent is moved so that the candle filter assembly (15) rests on the
stainless steel circular shaped third and sixth support plates (13&28)
respectively.Thereafter, the two major componentsare attached firmly with the
help of flanges (06 & 21) using bolts & nuts completes the strong split fixture
support device, which proVideseasyaccessand safe working environment during
repair and maintenance of the candle filter assembly thus reducing the
repair/maintenance time and cost. The split fixture support device allows the
candle filter assembly (15) to move sideways to accommodate in the device,
instead of lifting the whole candle assemblyover the above the device. Thus it
reducesthe working time, cost and increasethe productiVity.
Referring to figure 5, an alternative embodiment of the device is illustrated,
wherein the device further comprises; a plurality of hinges (30) welded at the
free ends of said plurality of third box-channels (03) and the free ends of the
plurality of eighth box-channels (18) to swivel the second major component
componentsto attach or detach the components.
WE CLAIM:
1. A split fixture-support device for easy erection, repair and maintenance of
barrier filter candle assembly at elevated position in pressurized fluidized
bed gasification system, comprising a first major component and a
second major component, wherein the first and second major components
each comprises at least a plurality of support plates (13,28) and a plurality
of flanges (06,21), wherein the candle filter assembly (15) is disposed
above said support plate (13) of the first major component, wherein the
second major component is movable towards the first major component
such that the candle filter assembly rests on said support plates (13,28),
and wherein the major components are rigidly fixed with said flanges
(06,21) by fastening means to form the support device.
2. The device as claimed in claim 1, wherein the first major component
comprises:
a plurality of first box channels (01) to act as a horizontal supporting base
for the device; a plurality of second box-channels (02) positioned vertically
and welded to the first box channels (01); a plurality of third box-channels
(03) positioned horizontally and top-welded to both the first box-channel
(01) and second box-channel (02); a plurality of fourth box-channel (04)
positioned vertically and welded to both the first box-channels (01) and
third box-channels (03) to provide a vertical support to the device; a
plurality of structural angles (05) positioned horizontally and welded to the
third box-channels (03) to provide additional support to the device; a
plurality of plain plate flanges (06), positioned vertically and welded at the
free ends the third box-channels (03) to allow detachment and
attachment of the two major components; a fifth box-channel (07) welded
at top between two of said plurality of second box-channels(02) to act as
a first strut member of the device; a plurality of rectangular shaped first
support plates (08) positioned horizontally and welded at top of the
second box-channels (02) to bear the load and transfer the load to the
second box-channels (02); a plurality of trapezium shaped first stiffener
plates (09) positioned and welded between the second box channels (02)
and said first support plates (08); a plurality of rectangular shaped
bracings (10) positioned and welded below the first stiffener plates (09); a
plurality of 'L' shaped second support plates (11) positioned vertically
above the first support plates (08) and welded to bear the load and
transfer the load to the second box-channels (02); a plurality of
rectangular shaped second stiffener plates (12) positioned and welded
vertically at both sides of the 'L' shaped support plates (11); a plurality of
stainless steel circular shaped third support plates (13) positioned
horizontally above the 'L' shaped second support plates (11) and said
rectangular shaped second stiffener plates (12) and welded to hold said
candle filter assembly (15); and a plurality of square shaped dummy
plates (14) welded at the open ends of the first box channels (01) and
second box channels (02) to prevent the unwanted materials to get inside
the box channels.
3. The device as claimed in claim 1, wherein the second major comprising: a
plurality of sixth channels (16); a plurality of seventh box-channels (17)
positioned vertically and welded to the sixth box-channels(16); a plurality
of eighth box-channels (18) positioned horizontally and welded to the top
of both the sixth box-channel (16) and seventh box-channel (17); a
plurality of ninth box-channel (19) positionedvertically and welded to both
the sixth box-channels(16) and eighth box-channels(18); plurality of
structural angles (20) positioned horizontally and welded to the eighth
box-channels (18) to provide extra support to the device; a plurality of
plain plate flanges (21) positioned vertically and welded at the free ends
of the eighth box channels (18); a tenth box-channel (22) positioned
between two of the plurality of seventh box channels (17) at top and
welded to as a second strut member; a plurality of rectangular shaped
fourth support plates (23) positioned horizontally and welded at top of the
seventh box-channels (17); a plurality of trapezium shaped third stiffener
plates (24) positioned and welded between the seventh box channels(17)
and the fourth support plates (23); a plurality of rectangular shaped
bracings (25) positioned and welded below the third stiffener plates (24);
a plurality of 'L' shaped fifth support plates (26) welded vertically above
the fourth support plates (23) to bear the load and transfer the load to
the seventh box-channels (17); a plurality of rectangular shaped fourth
stiffener plates (27) welded vertically at both sides of the 'L' shapedfourth
support plates (23); a plurality of stainless steel circular shaped sixth
support plates (28) welded horizontally above both the 'L' shaped fifth
support plates (26) and rectangular shaped fourth stiffener plates (27) to
hold the candle filter assembly (15); a plurality of square shaped dummy
plates (29) welded at the open ends of the sixth box-channels (16) and
seventh box channels (17) to prevent the unwanted materials to get
inside the box channels.
4. The device as claimed in claim 1, further comprising; a plurality of hinges
(30) welded at the fee ends of the plurality of third box-channels (03) and
the free ends of plurality of eighth box-channels (18) to allow swiveling of
the second major component to enable attachment or detachment of the
two major components without totally removing the components from the
assembly location.

ABSTRACT

The invention relates to a split fixture-support device for easy erection, repair
and maintenance of barrier filter candle assembly at elevated position in
pressurizedfluidized bed gasification system, comprising a first major component
and a second major component, wherein the first and second major components
each comprises at least a plurality of support plates (13,28) and a plurality of
flanges (06,21), wherein the candle filter assembly (15) is disposed above said
support plate (13) of the first major component, wherein the second major
component is movable towards the first major component such that the candle
filter assembly rests on said support plates (13,28), and wherein the major
components are rigidly fixed with said flanges (06,21) by fastening means to
form the support device.