FIELD OF THE INVENTION
The present invention generally relates to a large spanned double conveyor
gallery structure of coal handling plants in a thermal power plant. More
particularly, the present invention relates to a weight optimized large spanned
double conveyor gallery system for coal handling plants.
BACKGROUND OF THE INVENTION
The double conveyor gallery is one of the important systems in coal handling
plants. The double conveyor gallery allows transportation of the material from
port to bunker or storage yard and then to the boiler. The storage yard is
normally located far away from the thermal power station for safety purpose. So,
the coal needs transportation for long distances along conveyor galleries. These
galleries can be of various lengths, and supported by trestles and transfer towers
particularly where, a conveyor has to change its direction. In general, a double
conveyor gallery comprises two conveyor belts and its supporting arrangements,
space for walkways, provision for fire fighting pipes including potable water
pipes, cable trays, lighting arrangements. The gallery is covered by roof sheeting
and side sheeting to protect the coal from any transmission loss due to wind or
rain.
Although the prior art documents CN202080735U and CN202080669U disclose
system having a portal-rigid frame substructure positioned inside a truss main
structure. The main object of these prior art is to prevent the system from fire
hazards and corrosion effects rather than focusing on optimizing the structural
member and joining process to reduce the weight of the system.
The existing arrangements for double conveyor galleries consist of only standard
rolled sections (flat members) and are not optimized from techno-economics

considerations. It contains large number of built-up and heavy sections. Under
utilization of material increases total weight of the structure and presence of
built-up sections in the structure increases welding requirements which in turn
extends the fabrication time. Thus, the prior art fails to address the problems of
optimizing the system to ensure maximum utilization of material, reduction in
welding requirement, minimizing the number of built up sections, and reducing
the overall weight of the system.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to propose a weight optimized
large spanned double conveyor gallery system for coal handling plants, which
eliminates the disadvantages of prior art.
Another object of the present invention is to propose a weight optimized large
spanned double conveyor gallery system for coal handling plants, which enables
selection of the constituting structural members including the joining sequence to
produce a system with reduced weight.
A still another object of the invention is to propose a weight optimized large
spanned double conveyor gallery system for coal handling plants, which can
withstand heavy wind load conditions.
A further object of the present invention is to propose a weight optimized large
spanned double conveyor gallery system for coal handling plants, which can
operate at various heights from ground.
A still another object of the present invention is to propose a weight optimized
large spanned double conveyor gallery system for coal handling plants, which

prevents excessive deflection of the system and limit the stresses to an
acceptable safe limits under severe wind load conditions.
SUMMARY OF THE INVENTION
Accordingly there is provided a weight optimized large spanned double conveyor
gallery system for coal handling plants, the system comprises two end portal
frames one each located at a first and a second end of the conveyor gallery and
a plurality of intermediate portal frames each placed in-between the first and
second end at equi-distance spacing.
The present invention is based on a parametric optimization of one such
standard double conveyor gallery. The present invention of double conveyor
gallery structure per se constitutes two end portal frames, plurality of
intermediate portal frames, walkway beams, lattice girders, purlins, side runners,
rafters and bracings. The present invention bridges the gap of optimized design
from conventional design for a double conveyor gallery.
According to the invention, standard pipe sections are introduced in the inventive
conveyor galleries. Almost 30% of the structural components of the gallery are
made of pipe sections. Pipe sections are preferred over standard flat sections
because of the following reasons:-
i. The force coefficient of circular sections are almost 30% less when
compared to flat sections which results in huge reduction in wind load
acting on the structure.
ii. The load carrying capacity of the conveyor galleries increases because of
increase in moment of inertia.
iii. Circular sections have as much as 30 to 40% less surface area than that
of an equivalent rolled shape and thus reduces the cost of maintenance,

cost of painting.
iv. There is no better section than the tubular one for torsional resistance.
v. Tubes are of special interest to architect from an aesthetics view point.
vi. The external surface of the tube does not permit the collection of moisture
and dust thus reducing the possibility of corrosion.
These portal frames per se constitute a plurality of vertical side members,
several horizontal beams at the top and bottom, and multiple inclined roof
members and stiffeners. Similarly the intermediate frames constitute a plurality
of vertical side members, several horizontal beams at the top and bottom,
multiple inclined roof members termed as rafters, and a plurality of truss
members at top and bottom. The portal frames and the intermediate frames are
connected by bottom chord members for example, walkway beams, lattice
girders and bracings at the bottom; and top chord members for example, lattice
girders and bracings at the top, side runners at the sides, purlins and roof
bracings at the top of the inclined members.
According to the present invention, the input technical parameters for the
proposed system are processed and a mathematical model of the system is
developed which is followed by incorporation of the values of load acting on the
system so as to optimize the constituent members including the forming process
such that the overall weight of the system is reduced, and codal provisions
including the stability of the structure is maintained. The system is then used for
fabrication of the structure.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The accompanied drawings describe the invention in detail and illustrate the
features; aspects, and advantages of the present invention. Reference numerals
are used for locating the component of the system. The invention may be readily

understood and carried into practical effect based on the following description
taken the conjunction with the accompanying drawings, wherein:
Figure 1 - shows a side view of a large spanned weight optimized double
conveyor gallery system according to the invention
Figure 2 - shows a front view of a large spanned weight optimized double
conveyor gallery system of Figure-1.
Figure 3 - shows an expanded view of end portal frame (A) of the double
conveyor gallery system of Figure-1.
Figure 4 - shows an expanded view of an intermediate portal frame (B) of the
system of Figure-1.
Figure 5 -shows an enlarged view of a bottom chord member (C) of the system
of Figure-1.
Figure 6 - shows an enlarged view of a top chord member (D) of the system of
Figure-1
Figure 7 - shows a magnified view of side members (E) of the system, and as
marked in figure-2
Figure 8 - shows a magnified view of roof top members (F) of the system, and
as marked in figure 2.
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 shows the side view of the large-spanned double conveyor gallery

system in accordance with a preferred embodiment of the invention. Two end
portal frames (A) which are placed at the beginning and at the end of the
conveyor gallery are connected by a plurality of intermediate frames (B). At the
bottom, a plurality of bottom chord members (C) connects both the end portals
frames (A) and the intermediate portals frames (B) in a longitudinal direction. At
the top, the top chord members (D) connect both the end portal frames (A) and
the intermediate portals frames (B) in the longitudinal direction. At the sides, the
side bracing along with side runners (E) (figure 7) connects the frames on both
sides. At the roof top (F), the purlins and roof bracing connections are shown in
figure 8.
According to the invention, the portal frames (A) as shown in figure 3 consists of
a horizontal bottom beam (1) connected to the side vertical of the end portals
(2a and 2b) which is associated with the inclined roof members (3a and 3b). The
horizontal top beam (5), inclined stiffeners at top and bottom (4a, 4b, 4c, 4d)
horizontal stiffeners (4e) and vertical stiffeners (23) are provided for additional
stability along with the other members. At the bottom of the side verticals (2a
and 2b) of end portals, the supporting members (6) are connected. More of the
sections in the end portal frame (A) are made up of standard I sections except at
some high stress regions, where built-up I sections are provided.
The intermediate portal frames (B) (see figure 4) are placed at an equi-distance
in between both the end portal frames (A). It consist of a plurality of horizontal
bottom member (7) fastened to the intermediate side vertical (8a and 8b) and at
the top with inclined roof member (rafter) (9a and 9b) and horizontal top
member (11). The inclined roof member (9a and 9b) and the horizontal top
member (11) are linked with a plurality of truss members (10a, 10b, 10c, 10d,
10e, 10f, 10g, 10h,10i, 10j, 10k, 10l, 10m). The inclined roof member and the
truss members are made up of pipe sections. The side verticals (8a and 8b),

horizontal top members (11) and horizontal bottom members (7a), are all made
up of standard channel sections. Built-up sections made with parent section are
used at the high stress regions of the horizontal bottom members (7b). The
inclined truss members (12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h, 12i, 12j) and
horizontal cross beams (13) provided at the bottom of each intermediate portal
(all are made up of pipe sections), ensures additional stiffness to the horizontal
bottom member.
The bottom chord member (C) (see figure 5) consists of a plurality of connecting
members attaching the bottom part of the frames. It consists of lattice girder
(14a, 14b) on both sides. In between, the walkway beams (15a, 15b, 15c, and
15d) are provided to support the walkway floors and the conveyor belt supports.
These are again standard channel sections but of lower size than the lattice
girder. Horizontal cross beams (13) and lattice girders (14a, 14b) are interlinked
by bottom bracings (16) made up of pipe sections. The top chord member (D)
consists of a plurality of connecting members attaching the top plane of the
frames. The lattice girder (17a, 17b) consists of box sections made up of
standard channel sections. The lattice girders and the horizontal top members
(11) at the top chord are inter-connected by bracings (18) made up of pipe
sections.
At the sides (E) (see figure 7) the side bracings (19a and 19b) are used to
connect the end portals and the first intermediate portal frames. They are made
up of standard pipe sections. The side runners (20a, 20b, 20c, 20d, 20e, 20f)
hold the side sheeting and are supported by the portal frames in the longitudinal
direction. These side runners are made up of standard channel sections.
At the roof top (F) (see figure 8) the purlins (21a, 21b, 21c, 21d, 21e, 21f, 21g,
21h, 21i and 21j) are connected along the longitudinal direction. The purlins are

used to hold the roof sheeting and are supported at the inclined roof level at
certain intervals. The roof bracings (22a, 22b) at the roof top as shown in figure
1, and these bracings are made up of pipe sections. Walkway runners (24a to
24f) are provided at the bottom chord in order to support chequered and seal
plates, these members are made up of standard channel sections.
In order to account for the high stress levels, side verticals (8a, 8b), rafters (9a,
9b), side bracings (19a, 19b), top chord bracings (18a, 18b), bottom chord
bracings (16a, 16b) and horizontal top member (11a, 11b) employed at the end
of gallery span are provided with heavier sections than those at the intermediate
locations.
For example, a double conveyor gallery at the range of 22 to 26 m span can be
taken to explain the process of this proposed system. The structural data
considered based on the following technical parameters:-



The logic generated takes into account the above parameters and place the
frames at the respective locations and connect accordingly. The members are
grouped according to their function and location and the logic to select the
property is given in such a way that each group has a particular section size.
The parameters considered for load application are as follows

The following table gives the comparison between the existing and the optimized
design of the conveyor gallery system formed, with pipe sections, for a given set
of aforementioned parameters.

From the above table it is seen that the inventive system formed with pipe
section, local stiffening arrangement and bracing pattern, has lower structural
weight and reduced number of built-up sections which inter alia reduces the

welding requirements. These make the present invention to be better than the
existing systems.
The inventive system can be used for any material handling plant like coal, steel,
lime etc., because the model developed provide data irrespective of the material
being carried.
While the illustrative embodiments of the disclosure has been described above, it
will be recognized and understood that various modifications can be made to the
embodiments and the appended claims are intended to cover all such
modifications which may fall within the spirit and the scope of the disclosure.

WE CLAIM
1. A weight optimized large spanned double conveyor gallery system for coal
handling plants, comprising:
- at least two end portal frames disposed at each end of the system;
- a plurality of intermediate portal frames connecting the end portal frames;
- a plurality of bottom chord members connecting the intermediate portal
frames and the end portal frames in a longitudinal direction at the bottom
portion of the system;
- a plurality of top chord members connecting the end portal frames and
the intermediate portal frames at the top portion of the system;
- a plurality of roof top members connected along the longitudinal direction;
and
a plurality of side runners connecting the system at both sides,
wherein the intermediate portal frames are placed at an equi-distance
between both the end portal frames.
2. The system as claimed in claim 1, wherein the end portal frames are
enclosing a roof portion and plurality of side vertical members extending
downwards from the roof portion with a plurality of side stiffeners along
with horizontal bottom and top members with vertical stiffener in-
between, leaving an opening in the middle.
3. The system as claimed in claim 1, wherein the intermediate portal frames
consist of a plurality of frames, with each frame enclosing a roof portion
and plurality of side vertical members extending downwards from roof
portion with a plurality of truss members and horizontal top members,
leaving an opening in the middle.

4. The system as claimed in claim 1, wherein the bottom chord members
comprising a plurality of lattice girders, wherein the lattice girders, the
end portal frames, intermediate portal frames, walkway beams and
walkway runners are connected with patterned bracings along the
longitudinal direction to form a support system at the bottom plane, and
wherein, below the horizontal bottom member, a plurality of truss
members is connected to a horizontal cross-beam to enhance the strength
of the bottom chord.
5. The system as claimed in claim 1, wherein the top chord members
comprising a plurality of lattice girders wherein, the lattice girders, the
end portal frame with patterned bracings are connected along the
longitudinal direction to form a support system at the top plane.
6. The system as claimed in claim 1, wherein the roof top members
comprising a plurality of purlins and wherein the roof top members, the
end portal frames and intermediate portal frames with patterned bracings
are connected along the longitudinal direction at the top plane of the roof
in order to support roof sheetings placed on top of it.
7. The system as claimed in claim 1, wherein the side runners, in order to
support the side sheeting, provided with a plurality of side runners
connecting the end portal frames and intermediate portal frames in the
longitudinal direction with bracing pattern at the side planes.
8. The system as claimed in claim 1 or 2, wherein the side verticals consist of
built-up I sections at specified high stress region including the supporting

member, the rest of the side verticals being made up of standard I
sections.
9. The system as claimed in claim 1 or 2, wherein the horizontal bottom
members consist of built-up I sections at the specified high stress region,
the rest of the horizontal bottom members being made up of standard I
sections.
10. The system as claimed in claim 1 or 2, wherein the inclined roof portion
consists of standard I section and connected with side stiffener which is
made up of standard I section cut beam.
11. The system as claimed in claim 1 or 2, wherein the horizontal top
members made up of standard channel section are connected to side
verticals for more stability.
12. The system as claimed in claim 1 or 2, wherein the vertical member made
up of standard angle section connected between the horizontal top
member and the inclined roof portion.
13. The system as claimed in claim 1 or 3, wherein the horizontal bottom
members consist of plurality of standard channel sections except at
specified high stress regions and such locations are made up of built-up
channel sections.
14. The system as claimed in claim 1 or 3, wherein the bottom truss members
and horizontal cross beams are made up of pipe sections.
15.The system as claimed in claim 1 or 3, wherein the side verticals are made
up of a plurality of standard channel sections.

16. The system as claimed in claim 1 or 3, wherein the roof portion consists of
pipe sections connected by tubular truss members.
17. The system as claimed in claim 1 or 3, wherein the horizontal top beam is
made up of standard channel sections connected to the side verticals.
18. The system as claimed in claim 1 or 4, wherein the lattice girder consists
of built-up channel section connecting the frames in the longitudinal
direction.
19. The system as claimed in claim 1 or 4, wherein the walkway beam is
made up of standard channel section.
20. The system as claimed in claim 1 or 4, wherein the walkway runners are
made up of standard channel section.
21. The system as claimed in claim 1 or 4, wherein the intermediate portal
frames and end portal frames are connected by bracings made of pipe
section.
22. The system as claimed in claim 1 or 5, wherein the lattice girder
connecting the intermediate portal frames and end portal frames are box
section made up of standard channel section.
23. The system as claimed in claim 1 or 5, wherein the intermediate portal
frames and end portal frames are connected by bracings made of pipe
section.

24. The system as claimed in claim 1 or 6, wherein the purlins are connected
on top of the roof members in order to support the roof sheeting and
constitute standard channel sections.
25. The system as claimed in claim 1 or 6, wherein the roof bracings are
connected at particular locations in order to provide stiffness in lateral and
longitudinal directions and constitute standard pipe sections.
26. The system as claimed in claim 1 or 7, wherein the side runners are
standard channel sections.
27. The system as claimed in claim 1 or 7, wherein the bracings are
connected in longitudinal direction to provide rigidity in both longitudinal
and vertical directions which constitute standard pipe section.

ABSTRACT

The invention relates to a weight optimized large spanned double conveyor
gallery system for coal handling plants, comprising at least two end portal frames
disposed at each end of the system; a plurality of intermediate portal frames
connecting the end portal frames; a plurality of bottom chord members
connecting the intermediate portal frames and the end portal frames in a
longitudinal direction at the bottom portion of the system; a plurality of top
chord members connecting the end portal frames and the intermediate portal
frames at the top portion of the system; a plurality of roof top members
connected along the longitudinal direction; and a plurality of side runners
connecting the system at both sides, wherein the intermediate portal frames are
placed at an equi-distance between both the end portal frames. Both end portal
and intermediate portal frames consist of plurality of localized stress regions
which are strengthened with built-up sections made from the parent section.
Plurality of members in the side verticals, side bracings, top chord bracings,
bottom chord bracings and horizontal top member employed at the end of the
gallery span which each constitutes heavier sections than those at the
intermediate locations.