FIELD OF THE INVENTION
The present invention relates to segregation of sinter-mix during charging into moving pallets.
BACKGROUND OF THE INVENTION AND PRIOR ART
Size-wise segregation of sinter-mix particles in sinter-bed formation on continuously moving
pallets is a critical process requirement for better sinter making. Sinter-bed with efficient
segregation of sinter-mix i.e., coarser particles at the bottom portion and finer particles at the top
portion of the sinter-bed, improves the bed permeability. The good permeable sinter-bed
improves air filtration velocity across the sinter bed, which intern improves the productivity of
the sinter machine through increased machine speed. The size-wise segregation of particles of
sinter-mix is achieved during charging of sinter-mix on the moving pallets through a
conventional sloping chute, installed below the drum feeder of the sinter machine. However the
efficiency of segregation is depends upon the rolling-length of the sloping chute, i.e., the distance
of sliding of sinter-mix in the sloping chute before discharged into the moving pallets. As the
rolling-length of the sloping chute is limited due to location constraints, the segregation is also
limited. To improve the segregation of the sinter-mix, various mechanical devices were tried by
various innovators by replacing the conventional sloping chute.
An improved multiple rollers based charging chute is another invention to improve the
segregation of sinter-mix, which replaces the conventional sloping chute, provided below the
drum feeder of the sinter machine.
Earlier method of size-wise segregation of sinter-mix to form a permeable sinter bed
The sinter-mix from the storage hopper is continuously extracted by a drum feeder, provided
below the hopper and discharged into the forward moving pallets of the sinter machine, through
a stationary sloping chute. The sloping chute is a solid rectangular plate, placed below the drum
feeder, at an inclined position suitable for smooth material flow by sliding for charging into the
forward moving pallets. The sloping chute helps to achieve size-wise segregation of sinter-mix in
sinter bed, as the coarser particles slides down faster than finer particles and reaches the bottom
of the pallet to form bottom portion of the bed. The finer particle, which reaches the pallet after

the coarser particles due to lower sliding velocity, charged on the top of the coarser particles and
hence forms the top portion of the sinter bed.
The length i.e., distance of travelling/sliding of sinter-mix over the surface of the sloping chute
i.e., "rolling-length" is a critical parameters, which affects the segregation of sinter-mix particles.
The distance of travelling (sliding) of sinter-mix particles on the surface of the sloping chute is
directly proportional to effectiveness of segregation. If the length of rolling is increased, the
segregation of particles improves. However the rolling-length of the conventional sloping chutes
is limited due to various constraints such as fixed location, positions of upstream and
downstream equipment etc., and hence the level of segregation of sinter-mix particles is also
limited.
Further to the above constraints in the conventional sloping chute for effective segregation of
sinter-mix particles, there are some more operational problems observed in conventional sloping
chute, such as building - up of material on the surface of the sloping chute, which restricts the
smooth flow/sliding of sinter-mix materials through the sloping chute. This sticking behavior of
sinter-mix particles on the surface of the chute, which need frequent manual interventions to
clear the flow, also affects the segregation of material on the sinter bed.
OBJECTS OF THE INVENTION
A basic object of the present invention is to overcome the disadvantages/drawbacks of the known
art.
Another object of the present invention is to replace the conventional charging sloping chute,
without affecting the performance of various upstream and downstream equipments of the sinter
making process.
Another object of the present invention is to design and develop a multiple rollers based charging
chute for efficient segregation of the sinter-mix during charging into moving pallets.
Another object of the present invention is to provide additional features to the multiple rollers
chute assembly for efficient operation and maintenance at site.
Another object of the present invention is to eliminate sticking of sinter-mix on surfaces of the
conventional sloping chute, which obstructed free flow of material into the pallets.

Another object of the present invention is to improve sinter machine speed and productivity of
sinter plant.
Another object of the present invention is to reduce the generation of (-) 5 mm return sinter fines
by improving the strength of sinter.
Yet another object of the present invention is to reduce dust entering in the wind main system
through online hearth layer generation by the system
These and other advantages of the present invention will become readily apparent from the
following detailed description read in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
The following presents a simplified summary of the invention in order to provide a basic
understanding of some aspects of the invention. This summary is not an extensive overview of
the present invention. It is not intended to identify the key/critical elements of the invention or to
delineate the scope of the invention. Its sole purpose is to present some concept of the invention
in a simplified form as a prelude to a more detailed description of the invention presented later.
The General Arrangement of multiple rollers based segregation chute is depicted in Fig. 1 and
the details of the multiple rollers assembly are depicted in Fig. 2.
According to one of the aspect of the present invention the system is provided an improved
system of a multiple rollers based charging chute to improve segregation of sinter- mix during
charging into pallets in sintering process, said system comprising:
plurality of bearing supports;
plurality of roller assembly having stub shafts mounted on bearing supports on both ends;
drum feeder located above said arrangement of multiple rollers assembly ;
plurality of geared motors adapted to drive said rollers;

a drive transmission assembly comprising: power transmission chain and sprocket drive
assembly;
mounting frame structure; and
control panel with VVVF controller adapted to drive said plurality of rollers;
such that plurality of rollers assembled in parallel position maintaining a uniform gap between
them.
Other aspects, advantages, and salient features of the invention will become apparent to those
skilled in the art from the following detailed description, which, taken in conjunction with the
annexed drawings, discloses exemplary embodiments of the invention.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The following drawings are illustrative of particular examples for enabling methods of the
present invention, are descriptive of some of the methods, and are not intended to limit the scope
of the invention. The drawings are not to scale (unless so stated) and are intended for use in
conjunction with the explanations in the following detailed description.
Figure 1 illustrates general arrangement of multiple rollers assembly located below the drum
feeder of the sinter machine.
Figure 2 illustrates various components of the multiple rollers assembly.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWING
Figure 1 illustrates general arrangement of multiple rollers assembly located below the drum
feeder of the sinter machine. The multiple rollers assembly consists of 11 nos. of stainless steel
made rollers grouped together as a single unit through a single supporting frame. The total
assembly is installed in the same location, where the earlier conventional sloping chute was
installed. The total assembly can be tilted to vary the slope angle. The rollers assembly can also
be moved through sliding to vary the distance between the assembly and drum feeder.

Figure 2 illustrates various components of the multiple rollers assembly. The rollers (2) are
assembled in parallel, adjacent to one another maintaining a uniform gap between the rollers.
The rollers are of hollow type, maintaining uniform thickness across the length. The hollow
shafts are provided with stub-shafts (13) at their both ends, for support bearings (4). The rollers
are clubbed in two groups (6 rollers and 5 rollers), and are driven by an individual drive motors
(3). The drive motors are positioned diagonally opposite to each other, maintaining perfect
balance of the assembly. Suitable support base frames (la) are provided to support the drive
motors. All the eleven rollers are assembled into a single unit through common support frame
(12), for easy and convenient handling. The power of the drive roller is transmitted to other
driven rollers in series through chain and sprocket assembly. The bottom 6 rollers are clubbed
together and driven by a geared motor. The geared motor is directly connected to the main drive
roller, (2) through pin-bush type coupling (5). The power of the main drive roller is transferred to
the immediate next driven rollers (2a & 2al) through duplex type drive chain (7) and duplex type
drive sprocket (6) assembly. The power from the main driven rollers is transferred next driven
rollers through driven chain (7a), and driven sprocket (6a). The main supporting frame (12),
consists of side plates (1), motor base frame (la) and support pipes (8).
The main supporting frame (12) with its rollers assembly is fixed with sliding support frame (10)
at two hinge joints (9). With the hinge joints and slope-angle change mechanism (11), the slope-
angle of the rollers assembly is varied as per the process requirement.
The main supporting frame (12) with its rollers assembly can be slide front and back on a sliding
support frame (10) to adjust the gap between the rollers assembly and the drum feeder.
The drive geared motors are operated through individual VVF Drives, installed in the main
control room. The rotations of the rollers are varied in the range of 5 to 34 rpm. The rotations of
the rollers are uniform and in the direction, which help the charge material to falls down into the
pallets smoothly. As the rollers are driven through drive motors, the chances of sticking of sinter-
mix over the surface of the rollers are minimized.

Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity
and clarity and may have not been drawn to scale. For example, the dimensions of some of the
elements in the figure may be exaggerated relative to other elements to help to improve
understanding of various exemplary embodiments of the present disclosure.
Throughout the drawings, it should be noted that like reference numbers are used to depict the
same or similar elements, features, and structures.
In the following detailed description, reference is made to the accompanying drawings that form
a part hereof, and illustrate the best mode presently contemplated for carrying out the invention.
Further functioning of the system and method has been discussed below to describe the way it
operates. However, such description should not be considered as any limitation of scope of the
present system. The structure thus conceived is susceptible of numerous modifications and
variations, all the details may furthermore be replaced with elements having technical
equivalence. In practice the materials and dimensions may be any according to the requirements,
which will still be comprised within its true spirit.



Multiple Rollers Based sinter-mix charging Chutes:
In the new design of charging chute, the existing conventional stationary sloping chute has been
replaced with dynamic multiple rollers based charging chute to improve segregation of sinter-
mix particles to increase the sinter machine productivity and to eliminate the problem of sticking
of sinter-mix material on the surface of the conventional sloping chute.
The multiple rollers based charging chute consists of stainless steel made rollers with necessary
stub shafts, mounted on bearing supports on both ends, geared motors with power transmission
chain and sprocket drive assembly, mounting frame/structure, control panel with VVVF
controller etc. Number of rollers required in the assembly decided based on the maximum
possible rolling-length at site. The rollers of the assembly, assembled in parallel position
maintaining a uniform gap between them.

The multiple rollers based charging chute is installed at site in the place, where the earlier
sloping chute was installed. The rollers of the chute assembly are supported in single structural
frame on both sides, to form a single unit.
There are 11 nos. of rollers in the assembly. The assembly is divided into two groups as 6 nos. of
rollers and 5 nos. of rollers. Each group is driven by an independent geared motor. Both the
group is operated from a common control panel through an individual VVF drives. The
rotational speed of each group is independently variable and can also be synchronized with other
as per the process need. The rpm of the rollers can be varied in the range of 5- 34 rpm from the
main control panel, through operator's interface keypad of the VVVF controller. The actual rpm
of the each drive motor is shown in the panel in digital mode. RPM setting of each drive is set
manually through the operator interface keypads of VVF drive.
One local control panel is provided at site, nearer to the rollers assembly has the features such as
Selector Switch for Local/ Remote mode, "Start / Stop push button", "Light Indicators" etc.
The multiple rollers based chute assembly is installed with a sloping angle of around 55° with
horizontal plane. The sloping angle of the rollers assembly can be varied between 45° to 60°. The
feature to vary the slope angle is provided to adjust the angle at site as necessary to the quality of
input sinter-mix. The discharge point of the rollers assembly is also varied at site through a
sliding mechanism provided in the assembly. A 50 mm gap is maintained between the
bottommost roller of the assembly and top of the side plate of the pallets.
By this multiple rollers based charging chute assembly, efficient segregation of particles of
sinter-mix is achieved as the coarser particles ( ~ +4 mm) of the charge material slides down
with additional momentum by the rotating rollers, directly into the forward moving pallets and
occupies the bottom portion of the sinter bed. Whereas the finer particles (- 4 mm) falls through
the gaps between the rollers of the chute assembly on top of the coarser particles and occupies
top portion of the sinter bed.
The problem of sticking of sinter-mix on the surface of the sloping chute (made of mild steel) is
eliminated, as the rollers are made of stainless steel, which has less tendency for sticking of
material and the rollers are continuously rotating. This has improved maintenance of the chute
assembly.

The scheme of the proposed system is shown in the following drawings:
> The general arrangement of multiple rollers based assembly shown in the drawing No.:
Fig. 1
> The details of various components of the multiple rollers assembly is shown in the
drawing no.: Fig. 2.
SPECIFICATION OF MAIN PARTS OF ROLLERS ASSEMBLY:

The drive from motor is transferred to main drive roller directly through pin & bush coupling.
Form the main drive roller is transferred to immediate next driven roller through Duplex type
roller chain and matching drive sprocket. From the first driven roller is transferred to other
rollers by simplex type roller chain and sprockets.


Features:
> Multiple rollers based charging chute for improving the segregation of sinter-mix for the
formation of sinter bed during charging of sinter-mix into the forward moving pallets of
sinter machine, with the following main features:
o 11 nos. of SS-304 made hollow rollers clubbed in 2 groups of 6 nos. & 5 nos.
o Uniform gap of 8 mm between the rollers
o Stub shaft for end connections of the rollers with drives
o Two geared drive motor, located diagonally opposite to each other in the rollers
assembly
o Chain and sprocket type drive transmission arrangement,
o Provision of cross bars (support pipes) for strengthening the supporting frame
> The rotational speed of the multiple rollers assembly can be varied at site in the range of
5 to 34 rpm as necessary in the process to match with machine speed and input sinter-
mix.
> The slope angle of the "rollers assembly" can be varied at site in the range of 45o to 60o ,
as necessary in the process to match with input sinter-mix and optimum compaction for
effective bed permeability.
> The discharge point of the rollers assembly for charging the sinter-mix into the pallets
can be varied +/- 100 mm too suitably maintaining the distance/gap between the rollers
and the drum feeder, just by sliding the whole assembly front & back, along the sliding
support frame, as necessary in the process and for maintenance of the system.
> Installation and commissioning of the "multiple rollers" based charging chute at Sinter
Machine, by completely replacing the conventional charging/sloping chute.

Advantages:
The multiple rollers based charging chute was successfully installed and commissioned. Trials
were conducted before and after installation of the multiple rollers feeder assembly to estimate
the technological benefits. The data were recorded on three important fields such as
granulometry, air filtration and green charge, feed rate, productivity etc. The following
technological benefits were observed in the newly installed system:
> Improvement by 9% (absolute) in granulometry (-5 mm generation, %) at SSI belt source
from 22.11% to 12.89%
> The strength of the sinter (ISO, T.I (+6.3mm)) increased from 72.6 % to 76.6 % (abs)
> Increase in average air filtration velocity sucked through bed by 0.5 m/s from 0.22 m/s
> Increase in waste gas temperature at wind box no. 14 from 158°C to216°C
> Considerable increase in machine speed due to increase in the bed permeability affected
by enhanced segregation of sinter-mix. This is indicated by increase of waste gas
temperature at wind box no. 14.
> Reduction of dust entering in the wind main system due to online hearth layer generation
by the installed system.
> Increase in productivity of M/c # 4 by 4 % from 1.446 t/m2/h to 1.463 t/m2/h

WE CLAIM:
1. An improved system of a multiple rollers based charging chute to improve segregation of
sinter- mix during charging into pallets in sintering process, said system comprising:
plurality of bearing supports;
plurality of roller assembly having stub shafts mounted on bearing supports on both ends;
drum feeder located above said arrangement of multiple rollers assembly ;
plurality of geared motors adapted to drive said rollers;
a drive transmission assembly comprising: power transmission chain and sprocket drive
assembly;
mounting frame structure; and
control panel with VVVF controller adapted to drive said plurality of rollers;
such that plurality of rollers assembled in parallel position maintaining a uniform gap
between them.
2. System as claimed in claim 1 wherein said rollers are eleven is number clubbed in two
groups of six and five.
3. System as claimed in claim 1 wherein said roller made of stainless steel.
4. System as claimed in claim 1 wherein said one geared motor drives one group.
5. System as claimed in claim 1 wherein said roller having a rpm of 5-34 rpm.
6. System as claimed in claim 1 further comprises a local control panel.
7. System as claimed in claim 1 wherein said rollers having a gap of 8mm.
8. System as claimed in claim 1 wherein geared motor is two geared drive motor located
diagonally opposite in plurality of rollers.
9. System as claimed in claim 1 wherein said plurality of rollers based chute assembly is
installed with a sloping angle of around 55° with horizontal plane.
10. System as claimed in claim 1 wherein said roller having a sloping angle of the rollers
assembly can be varied between 45° to 60°.
11. System as claimed in claim 1 wherein said bottommost roller of the assembly and top of
the side plate of the pallets a 50 mm gap is maintained in between.

12. System as claimed in claim 1 wherein said roller assembly can be slide front and back by
+/- 100 mm from its neutral position i.e., 200 mm which is the gap between said rollers
assembly and said drum feeder.
13. System as claimed in claim 1 wherein said multiple rollers based charging chute
assembly, efficient segregation of particles of sinter-mix is achieved as the coarser
particles ( ~ +4 mm) of the charge material slides down with additional momentum by
the rotating rollers, directly into the forward moving pallets and occupies the bottom
portion of the sinter bed and finer particles (- 4 mm) falls through the gaps between the
rollers of the chute assembly on top of the coarser particles and occupies top portion of
the sinter bed.
14. System as claimed in claim 1 wherein said drive from motor is transferred to main drive
roller directly through pin & bush coupling.
15. System as claimed in claim 1 wherein said main drive roller is transferred to immediate
next driven roller through Duplex type roller chain and matching drive sprocket.
16. System as claimed in claim 1 wherein said first driven roller is transferred to other rollers
by simplex type roller chain and sprockets.
17. An improved system of a multiple rollers based charging chute to improve segregation of
sinter- mix during charging into pallets in sintering process as herein substantially
described and illustrated with the accompanying drawings.

ABSTRACT

The present invention relates to an improved system of a multiple rollers based charging chute to
improve segregation of sinter- mix during charging into pallets in sintering process. The system
comprises plurality of bearing supports(4); plurality of rollers (1) having stub shafts (13)
mounted on bearing supports on both ends; plurality of geared motors (3) adapted to drive said
rollers; a drive transmission assembly; mounting frame structure (12); and control panel with
VVVF controller adapted to drive said plurality of rollers. The drive transmission assembly
comprises power transmission chain and sprocket drive assembly (6, 6a, 7, 7a). The plurality of
rollers assembled in parallel position maintaining a uniform gap between them.