Field of the Invention
The present invention relates to modified fume extraction installation to remove
dust from fume emitting units of an industrial floor. The installation is specifically
suitable of removing dust of the fume from the ladle furnace and slab caster.
Background of the Invention
In metal manufacturing floor such as LD furnace slab caster a huge amount of
fume containing dust particles is generated and an efficient system to extract the
said particles calls for a development for building up an installation for the said
purpose to keep the manufacturing floor free of dust, preventing health hazards
and collection of the dust for reuse.
Existing system for extraction of dust in the ladle and slab caster is carried on by
rotary feeder attached with the FEI system which works with the help of motor
and gear boxes and filter bags to filter the dust particles which are disposed into
the bins arranged below the rotary feeder. This system requires lot of
maintenance for removing all the dust particles and is time consuming and cost
bearing.
To remove the constraint of the existing system the present invention proposes
to replace the rotary feeder by a rotary feeder box wherein dust get entry
through a manual flap gate and collecting the dust in catchers.
The said rotary feeder box can be adopted in all the FEI systems in an industrial
floor replacing the existing rotary feeder arrangement.

In the absence of motor and gear arrangement as in the existing rotary feeder, the modified
installation of the present invention does not require any maintenance or maintenance cost for
the rotary feeder, does not require any greasing in the moving parts, saves power in all respect
and saves cost directly by avoiding any installation of the rotary feeders.
Description of the Invention
According to the present invention there is provided a modified fume extraction installation to
remove dust from fume emitting units of an industrial floor comprising a duct (3) provided to
progress fumes extracted from a fume emitting unit via a roof cover (2) and a chamber (4) with
duct (3) and providing with means to hang plurality of filter bags in which particles of the fumes
emitting unit is filtered and egressed into rotary feeder duct (5) characterized in that the
atmospheric air inlet (6) is adapted with the rotary feeder box (7) to produce suctional force of
the filtered dust particles to be captured in a cluster (9) formed in the rotary feeder duct is then
be ingressed into the said rotary feeder box (7), allowing the flue gas separated from the
accompanying dust particles to escape in the atmosphere through a chimney (12) via a duct
(10) through an ID Fan (11) incorporated and coupled between the said duct and chimney and
filtered dust particles to be captured in a catcher (c) without any air leakage.
The present invention will be better understood by describing the performance of the invention
with the help of the accompanying drawings in which
Figure 1 represents a schematic diagram showing the exiting fume extraction installation
attached to the existing Rotary Feeder with gear and motor arrangement and a bin underneath
the rotary feeder to extract dust particle from LD furnace or slab caster or other furnaces.
Figure 2 represents a schematic diagram showing the Fume Extraction Installation attached
with the improved Rotary Feeder Box.

Figure 3 represents the details of the parts of the Rotary Feeder Box according to
the present invention.
In figure 1 the fumes emitted from the ladle cover (2) of the ladle (1) is fid to
an existing Rotary Feeder (RF) via a duct (3). A bin (B) placed underneath the
Rotary Feeder collects the dust particles which are filtered through filter bags
arranged in the bin and collected in the bin. The flue gas (10) after filtration is
extracted to the atmosphere via a chimney (12). The motor operated with Gear
Box (GB) provides the necessary suction in the rotary feeder for ingress and
egress of the dust particles in it and necessary suction for extraction of flue in
the atmosphere.
In Figure 2 the modified Fume extraction installation has been shown in which
fumes from the ladle furnace (1) is emitted through a ladle roof (2) into a duct
(3) (as separated from the existing Fume extraction system wherein the Filter
Bags are arranged in the dust collector bin Itself). From duct (3) the fumes
enters a chamber (4) with arrangement to hang more than 500 filter bags. The
said filter bags filter the dust particles and allows the particles to enter a rotary
feeder duct (5) through the open months of the said bags. The flue gas
separated from dust particles from the chamber (4) is escaped to the
atmosphere via a duct (10) and chimney (12), necessary suctidnal force for such
extraction being provided by Internal Discharge Fan (ID Fan) (11). The said ID
Fan also provides the necessary rotary force in the Rotary Feeder Duct (5) to
lead the particles form a densed mass of dust (9) to impinge on the duett
internal peripheral wall and leading them to the Rotary Feeder Box (7). The said
dusts get ingress in the box (7) through a Flap Gate (8) which is being in fitting
arrangement with the feeder box adopted with a sealing gasket of rubber at its
periphery. Atmospheric air inlet (6) is adapted with the rotary feeder box to
produce suctional force of the filtered dust particles to be captured in a catcher
(C).

In Figure 3, the details of the flap gate and rotary feeder box are shown. The
flap gate (8) in fitting relationship with the feeder box (7) is operated through a
hinge (13). Atmospheric air inlet arrangements (6) at few points of the feeder
box (7) allow the flap gate to be closed during suction of dust particles,
regulated via the ID Fan.
The Rotary feeder box according to the proposed invention allow the installation
to be carried out continuously and ensure no air leakage through the feeder box
and ensure efficient removal of dust particles as opposed to the prior art
installation troubled with frequent stoppage of the FH on an average of 25 hrs
monthly running for maintenance of preventing air leakage, cleaning of all dusts
from the installation and motor and gear box maintenance.
The present invention should not be read in a restrictive manner as many
modifications, adaptations and changes can be made to form other embodiments
beyond the Illustrated one. For example the Fume extraction Installation
according to the invention can be adapted in any metal extraction plant, casting
plant producing fumes.
The scope and limit of the invention as narrated above is defined in the
appended claims.

WE CLAIM
1. A modified fume extraction installation to remove dust from fume emitting units
of an industrial floor comprising:
- a duct (3) provided to progress fumes extracted from a fume emitting unit via a
roof cover (2);
- a chamber (4) with duct (3) and providing with means to hang plurality of filter
bags in which particles of the fumes emitting unit is filtered and egressed into
rotary feeder duct (5);
characterized in that the atmospheric air inlet (6) is adapted with the rotary
feeder box (7) to produce suctional force of the filtered dust particles to be
captured in a cluster (9) formed in the rotary feeder duct is then be ingressed
into the said rotary feeder box (7), allowing the flue gas separated from the
accompanying dust particles to escape in the atmosphere through a chimney
(12) via a duct (10) through an ID Fan (11) incorporated and coupled between
the said duct and chimney and filtered dust particles to be captured in a catcher
(c) without any air leakage.
2. A modified fume extraction installation as claimed in claim 1 wherein necessary
suctional force for extraction of dust being provided by the ID Fan (11).
3. A modified fume extraction installation as claimed in the preceeding claims
wherein the flap gate (8) is operated through a hing (13), the flap gate being
closed during suction of dust particles by atmospheric air ingressed, through air
inlet arrangement (6) in the rotary feeder box (7).

4. A modified fume extraction installation as claimed in the preceeding claims
wherein the flap gate is fitted with the feeder box (7) operatable through a hinge
(13) mounted with a sealing gasket made of rubber sheet at its periphery.
5. A modified fume extraction installation as claimed in claim 1 wherein the fume
emitting unit is a LD furnace.
6. A modified fume extraction installation as claimed in claim 1 wherein the fume
emitting unit is a slab caster.
7. A modified fume extraction installation to remove dust from fume emitting units
of an industrial floor as herein described and illustrated.

This invention relates to a modified fume extraction installation to remove dust
from fume emitting units of an industrial floor comprising a duct (3) provided to
progress fumes extracted from a fume emitting unit via a roof cover (2), a
chamber (4) connected with the duct (3) and provided with means to hang
plurality of filter bags in which dust particles of the fume emitting unit is filtered
and egressed into a rotary feeder duct (5), the dense mass of dust particles (9)
formed into the rotary feeder duct is then ingressed into a rotary feeder box (7)
through a flap gate (13) adopted in the said rotary feeder box (7), the flue gas
separated from the accompanying the dust particles being escaped in the
atmosphere through a chimney (12) via a duct (10) through an ID Fan (11)
incorporated and coupled between the said duct and chimney.