WE CLAIM:
1. A two drum feeder system comprising:
a pair of drums (4, 5) having spikes(l1) on their external cylindrical surfaces
(1 8), said drums (4, 5) being rotatably mounted in a casing (6) with
their respective axis being substantially parallel to each other in a
horizontal plane and being mechanically coupled to a prime mover, each
of said drums (4, 5) being configured to rotate in a direction opposite to
each other, the spikes (1 1) being arranged on the drums (4, 5) in such a
manner that when rotated, the spikes (1 1) of one drum (4) do not interfere
with spikes (I 1) of other drum (5).
2. The two drum feeder system as claimed in claim 1, wherein the casing (6) of feeder
system comprises of bottom base frame (3), a middle casing (2) placed atop the
bottom base frame (3) and a top casing (1) over the middle casing (2).
3. The two drum feeder system as claimed in claim 1, wherein the casing(6) of feeder
system has a shroud (15) having atleast one shroud plate (15a, 15b) placed vertically
on each of two ends of the two drums(4,5) contiguous to the middle casing (2).
4. The two drum feeder system as claimed in claim 1, wherein the drums (4, 5) of the
feeder system have spikes (I 1) arranged on the entire cylindrical surface (18) of
drums (4,5).
5. The two drum feeder system as claimed in claim 4, wherein the spike (1 1) of the
drums (4, 5) of feeder system comprises of a central steel rod (12), and atleast one
side steel rod (13, 14) joined in parallel to each side of the said central steel rod (12)
where the central steel rod (12) is larger than the side steel rods (13, 14).
6. The two drum feeder system as claimed in claim 4, wherein the central steel rod
(12) and the atleast one side steel rod (13,14 ) of the spike (1 1 ) are hard faced to
580 - 620 brine11 hardness by weld overlay.
7. The two drum feeder system as claimed in claim 1, wherein the drums (4, 5) of the
feeder system are identical in size and spatially disposed with 300 rnm - 550 rnm
spacing between them.

TECHNICAL FIELD
The present invention relates to a two drum feeder system for extracting bagasse. More
particularly, the present invention relates to two drum feeder system for extracting bagasse
wherein the said drums are provided with drum spacing and inline spikes arrangement on drums
for extracting bagasse from the silo and feeding bagasse effectively in the system.
BACKGROUND
The waste materials from many commercial processes are burned to dispose off the materials and
to produce heat which can be economically used in the process to produce power. The process of
producing sugar from sugarcane is a typical commercial process where the waste materials
produced therein i.e. bagasse, can be economically burned.
Bagasse has a low heat value and a high moisture content when compared with commercial solid
or liquid fuel, such as coal or fuel oil. The character of the fiber is such that they tend to clump
together and form flocks, which makes it difficult to feed them with desired uniformity. Further,
the fibers tend to hang up, or jam, and plug the units of the system through which they may be
passed. Therefore, during the operation, more electrical power is consumed for a particular
capacity.
A bagasse feeder is known to have been provided in the art comprising of a single drum provided
with saw tooth blades and supported on a shaft. However, such bagasse feeders are associated
with certain disadvantages like honey comb effect of bagasse, thereby causing the jamming of
the feeder.
US Patent 2,796,198 discloses an apparatus for feeding bagasse using a furnace-stoker-feeder
system. The known apparatus is provided with a rotary feed drum and having a drum surface
spaced below the cutter edge. However, when dealing with bagasse like material, a single drum
system may not be very efficient.
US Patent 2,850,183 discloses a feeder for fibrous material using chain feeder for the delivery of
bagasse to a furnace and more particularly to an inclined chain feeder for the delivery of bagasse
to a hrnace. It discloses a feeder which is provided with an endless moving chain, or the like,
having a plurality of spaced upstanding fingers or spikes are projecting outwardly on endless
chain and intended to positively feed controlled amounts of a mass of bagasse resting thereon.
However, we try to eliminate the chain feeder in our system for better flow in the downstream
chutes and it prevents choking in the system.
Reference is made to continuous bagasse feeding system by Avante - Grade wherein single drum
feeder system is described. Single drum feeder is used in extracting the bagasse from a silo and
feeding the bagasse to a boiler using pneumatic spreaders. The drum centre in a single drum
feeder usually has an offset with silo centre to prevent column load acting directly on the drum.
This feature creates a gap in the feeder discharge point due to which the controllability of
bagasse is affected. When fibre size of bagasse is less, the same gets bypassed in the gap which
further affects controllability. When fibre size is too high, the feeder discharges the bagasse in
lump form. To break these lumps, a screw conveyor is used after single drum feeder prior to
feeding into the boiler.
OBJECTS OF THE INVENTION
The main object of the invention is to provide a two drum feeder system which can effectively
feed the bagasse or any other cellulose fuel into the system at a uniform rate without choking.
Another object of the present invention is to provide strong spikes with the two drums for
reducing the size of bagasse.
Yet another object of the invention is to simplify the construction.
SUMMARY
Accordingly, the present invention provides a two drum feeder system comprising:
a pair of drums having spikes on its external cylindrical surface and said drums being
rotatably mounted in an casing with the respective axis substantially parallel to each
other in a horizontal plane and being mechanically coupled to a prime mover and each of
the drums configured to rotate in a direction opposite to each other such that the spikes
are arranged on the drums in such a manner that when rotated, the spikes of one drum
does not interfere with spikes of the other drum , since the spikes of one drum are located
inan intervening gap between adjacent spikes of the other drum .
In an embodiment of the present invention, the casing of the two drum feeder system comprises
of bottom base frame, a middle casing placed atop the bottom base frame and a top casing over
the middle casing.
In another embodiment of the present invention, the casing of the two drum feeder system has a
shroud having atleast two shroud plates placed vertically on either end of the two drums
contiguous to the middle casing.
In yet another embodiment of the present invention, the two drum feeder system provides two
drums with spikes arranged on the entire cylindrical surface of drums.
In still another embodiment of the present invention, the two drum feeder system provides spikes
wherein each spike comprises of a central steel rod, and atleast two side steel rods joined parallel
to either side of the said central steel rod where the central steel rod is larger than the side steel
rods.
In yet another embodiment of the present invention, the two drum feeder system comprising the
central steel rod and the atleast two side steel rods of a spike are hard faced to 580 - 620 brine11
hardness by weld overlay.
In still another embodiment of the present invention, the drums are identical in size and spatially
disposed with 300 mm - 550mm spacing between them.
In yet another embodiment of the present invention, the prime mover used is an electric motor
mechanically coupled with a gear unit.
In yet another embodiment of the present invention, the electric motor is an alternating current
motor with power rating of 3.7 KW -7.5 KW electrically connected to a variable frequency
drive.
In still another embodiment of the present invention, the casing of the drums is provided
internally with 2mm thickness SA240Gr4091304 (SS4091304) liner.
ORIGINAb
2 5 AUG 20\1
0564 , .J
In yet another embodiment of the present invention, the spikes are offset to achieve the clear gap
of 80 mm - 230mm in between the tip of central steel rod of one drum to the tip of central steel
rod of the other drum to cut and push bagasse down.
In still another embodiment of the present invention, each drum has identical diameter from 200
mm - 400 mm.
In another embodiment of the present invention, each drum is connected with spur gears
mechanically coupled with gear unit.
In yet another embodiment of the present invention, one of the spur gears is directly coupled
with gear unit and electric motor through flexible gear coupling.
These and other features, aspects, and advantages of the present subject matter will become
better understood with reference to the following description and appended claims. This
summary is provided to introduce a selection of concepts in a simplified form. This summary is
not intended to identify key features or essential features of the claimed subject matter, nor is it
intended to be used to limit the scope of the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features, aspects, and advantages of the subject matter will be better
understood with regard to the following description, appended claims, and accompanying
drawings where:
Figure 1 shows a perspective view of a two drum feeder system in accordance with an
embodiment of present invention.
Figures 2a - 2d show a perspective view of the casings of two drum feeder system.
Figure 3a shows detailed cross- sectional view of spikes of drums.
Figure 3b shows detailed side view of spikes of the drums.
Figure 4a shows the top view of drums with spikes.
Figure 4b shows staggered arrangement of spikes of the drums.
Figure 4c shows the side view of the drums with spikes.
Figure 5a shows the side view of two drum feeder system with shroud plate.
Figure 5b shows the perspective view of shroud plates.
DETAILED DESCRIPTION WITH REFERENCE TO ATTACHED DRAWINGS
The present invention provides a two drum feeder system for extracting bagasse or other
cellulose fuel of similar character. The drums are provided with strong spikes for reducing the
size of bagasse. Drums are located in the lower section of the system. A driving mechanism is
provided to rotate the drums. A specially configured shroud arrangement is placed adjoining the
middle casing on the base frame housing two drums.
The two drum feeder system is an improved version of bagasse single drum feeder apparatus and
it can handle milled bagasse without choking. This can eliminate the screw feeder used down
below the single drum feeder for feed control.
The following paragraphs provide a detailed description of a non-limiting exemplary
embodiment of the two drum feeder system with reference to the drawings.
Fig. 1 is a perspective view of a two drum feeder system in accordance with an embodiment of
the present invention.
The design capacity of the two drum feeder system is 19500 kglh at 20 rpm. The higher speed is
selected to break the lumps into pieces.
The system comprises a pair of drums (4, 5) having spikes(l1) on its external cylindrical
surface (18) and said drums (4, 5) being rotatably mounted in a casing (6) with the respective
axis substantially parallel to each other in a horizontal plane and being mechanically coupled to a
prime mover and each of the said drums (4, 5) being configured to rotate in a direction opposite
to each other such that the spikes (1 1) are arranged on the drums (4, 5) in such a manner that
when rotated, the spikes (1 1) of one drum (4) does not interfere with spikes (I 1) of the other
drum (5).
In the present invention, the two identical drums (4, 5) are provided to extract the bagasse from
silo and control the same. The bagasse flow is varied!' controlled by varying the speed of electric
motor (10). The drums (4, 5) are having spikes (1 I), running at higher speed and facilitate the
extraction of bagasse from silo.
Both the drums (4, 5) are connected with spur gears (7, 8) and one spur gear (8) is coupled
byflexible gear coupling (16) andelectric motor (10). Speed is controlled through variable
frequency drive (VFD). This direct coupled arrangement is having less maintenance as compared
to other types of drum feeder/ extractors which are having chain link connections.
Each drum (4, 5) has identical diameter. Each drum (4, 5) is connected with spur gears (7, 8)
mechanically coupled with gear unit (9). One of the spur gears (7, 8) is directly coupled with
gear unit (9) and electric motor (10) through flexible gear coupling (16). The electric motor (10)
alongwith speed reduction gear unit (9) is mounted on a suitable base frame which rests on the
floor where two drum feeder system is placed.
The drive arrangement consists of 5.5 KW, alternating current geared motor, suitable for
operation with variable frequency control with planetary gear unit for the given capacity.
Figures 2a - 2d show perspective view of the casings of two drum feeder system.
The casing (6) comprises of a bottom base frame (3) as shown in fig.2c7 a middle casing (2) as
shown in fig.2b placed atop the bottom base frame (3) and a top casing (1) as shown in fig.2a
over the middle casing (2).Top casing (1) is slightly tapered in shape.
As shown in fig.2d the feeder casings are made up of 8 mrn thick carbon steel plate and lined
with 2 mm thick stainless steel plate (17) for corrosion resistance and to ensure the free flow of
bagasse. Split casings are provided with bolted connection to facilitate the access1 approach to
the drums (4, 5) in-situ. The casing (6) of the drums (4, 5) is provided internally with 2mm
thickness SA240Gr4091304 (SS4091304) liner
Figure 3a shows the detailed cross- sectional view of spikes of drums. The spikes (11) are
welded to the entire cylindrical surface (18) of the drums (4, 5) for better extraction of bagasse
from silo. The tips (1 la) of the spikes (1 1) are hardened to avoid erosion. The spike (11)
comprises of a central steel rod (12), and atleast two side steel rods (13,14 ) joined parallel to
either side of the said central steel rod (12) where the central steel rod (12 ) is larger than the side
steel rods
(13, 14). The central steel rod (12) and the atleast two side steel rods (13, 14) of a spike (1 1) are
hard faced to 580 - 620 brine11 hardness by weld overlay. The spikes (1 1) are offset to achieve
the clear gap in the range 80 - 230 rnm in between the tip of central steel rod (12) of one drum
(4) to the tip of central steel rod (12) of the other drum (5) to cut and push bagasse down.
Fig. 3b shows detailed side view of spikes of the drums. The spikes (1 1) are arranged on the
cylindrical surface (18) of the drums (4, 5).
Fig. 4a shows the top view of drums with spikes. The gap between the drums is strictly
maintained to attain the rated discharge capacity of bagasse. The drums rotate in an opposite
direction to each other, such that when in operation, the spikes of one drum appear to move
towards the space intervening adjacent spikes in the other drum when viewed from the feeding
(top) end, thereby bagasse is extracted from silo and discharge through the centre gap between
the drums (4, 5).The spacing between the drums (4, 5) is in the range 300mm to 550 mm to
extract the bagasse and push it down without choking. The drums (4, 5) are designed to rotate at
a high speed of 20 rotations per minute for the designed capacity.In the design, the drum spacing,
size, speed can be altered to have various capacity ranges.
Fig. 4b shows a staggered arrangement of the spikes of the drums. The spikes (I 1) of one drum
(4) are located in an intervening gap between the adjacent spikes (1 1) of the other drum (5).
Fig. 4c shows the side view of the drums with spikes.An additional stiffener (19) is provided on
the back of middle spike (1 1) to resist the tangential forces while extracting the fuel.
Fig. 5a shows the side view of two drum feeder system with a shroud plate. The casing (6) has a
shroud (15) having atleast two shroud plates (1 5a, 15b) placed vertically on either end of the two
drums (4,5) contiguous to middle casing (2).
Fig. 5b shows the perspective view of the shroud plates. Specially designed shroud plates
(15a,15b) prevent the bagasse entry on the sides of the drums. This prevents choking and
associated jamming which can cause more power consumption and feeder trip during the
operation of the system.

WE CLAIM:
1. A two drum feeder system comprising:
a pair of drums (4, 5) having spikes(l1) on their external cylindrical surfaces
(1 8), said drums (4, 5) being rotatably mounted in a casing (6) with
their respective axis being substantially parallel to each other in a
horizontal plane and being mechanically coupled to a prime mover, each
of said drums (4, 5) being configured to rotate in a direction opposite to
each other, the spikes (1 1) being arranged on the drums (4, 5) in such a
manner that when rotated, the spikes (1 1) of one drum (4) do not interfere
with spikes (I 1) of other drum (5).
2. The two drum feeder system as claimed in claim 1, wherein the casing (6) of feeder
system comprises of bottom base frame (3), a middle casing (2) placed atop the
bottom base frame (3) and a top casing (1) over the middle casing (2).
3. The two drum feeder system as claimed in claim 1, wherein the casing(6) of feeder
system has a shroud (15) having atleast one shroud plate (15a, 15b) placed vertically
on each of two ends of the two drums(4,5) contiguous to the middle casing (2).
4. The two drum feeder system as claimed in claim 1, wherein the drums (4, 5) of the
feeder system have spikes (I 1) arranged on the entire cylindrical surface (18) of
drums (4,5).
5. The two drum feeder system as claimed in claim 4, wherein the spike (1 1) of the
drums (4, 5) of feeder system comprises of a central steel rod (12), and atleast one
side steel rod (13, 14) joined in parallel to each side of the said central steel rod (12)
where the central steel rod (12) is larger than the side steel rods (13, 14).
6. The two drum feeder system as claimed in claim 4, wherein the central steel rod
(12) and the atleast one side steel rod (13,14 ) of the spike (1 1 ) are hard faced to
580 - 620 brine11 hardness by weld overlay.
7. The two drum feeder system as claimed in claim 1, wherein the drums (4, 5) of the
feeder system are identical in size and spatially disposed with 300 rnm - 550 rnm
spacing between them.