Birla Copper Pipe Conveyor - India

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Innovations in Pipe Conveyors

Phil Staples of Conveyor Knowledge and Information Technology describes India's largest Pipe Conveyor

Until the 90's conveyors in excess of 500m were very rare. Today, however, increased pipe conveyor lengths compete with those of more conventional belt conveyors. The longest single flight is over 5km and the largest pipe diameter is over 600mm.

Conveyor Knowledge and Information Technology (ConveyorKit) in collaboration with Naveen Projects India and other partners have successfully completed the installation of one of the world's largest pipe conveyors in Bharagh India. The unique features of this conveyor are its length of 3200m in single flight, it has a 90 degree 300m horizontal curve at the head end and it has a capacity of 1800tph using a 450mm diameter pipe. With these credentials, this pipe conveyor can be considered to rate with the biggest and best in the world.

The belt is 1650mm wide of steel cable construction. To ensure it was capable of operation in a curve without buckling, a 10m portion of the belt was manufactured prior to the manufacture of the complete belt. the sample belt was made in Korea and shipped to Wits University in Johannesburg where it was tested in a purpose-made jig which both tensioned the belt to the operating tension and curved it through the required radius.
Measurements of rubber indentation as the belt passed over the idlers was recorded, allowing the calculation of the belts required modulus of elasticity, to avoid buckling, to be obtained. The belt was then tested during manufacture to ensure that the required design parameters were maintained.

Unique Features

Other unique features of the design was computer simulation of the full dynamic analysis of the starting and stopping features of the conveyor. This resulted in the use of 3 x 500kw primary, secondary and tail drives each with a flywheel to reduce belt sag at the start of the horizontal/vertical curve, and a brake after the take-up to reduce take-up travel.

Commissioning of the conveyor was carried out in February 1999 after a two year construction program. Cold commissioning of the conveyor was restricted to 2 days prior to offloading 12000 tons of rock phosphate from a ship.

Problems associated with cold commissioning were confined to communication between head and tail drives only because thyristor controlled drives allowed technicians to creep the belt to set the belt training. Return belt training was not required and problems of the empty belt training on the carry strand had already been anticipated and provided for by placing strict control on the structural erection to maintain very close level tolerances. This reduced training problems to those caused by splicing only, with these problems being present on two of the thirty splices. However rotation of the pipe was contained to plus/minus 45 degrees in the curved portion for the empty belt and, during hot commissioning, the belt remained on line and was very stable through its entire length.

The pipe conveyor has been operating successfully since installation, and has started a new trend in the acceptance of high capacity long pipe conveyors.

Pipe Specifications

The pipe conveyor specifications are as follows:-

1 Conveyor length, pulley centers 3120m
2 Overall lift 22,0m
3 Belt speed 4,5m/s
4 Conveyor capacity 1600tph (initial); 2200tph (future)
5 Factor of safety (design) ~8,0 (initial); 5,2 (future)
6 Pipe diameter 450mm
7 Belt width x thickness 1650mm x 17,8mm
8 Belt specification and covers ST1000, 8 x 6mm covers
9 Horizontal radius 300m
10 Vertical inclination (max.) 5,74 degrees
11 Horizontal deflection 90 degrees
12 Location of take-up Head-end
13 Type of take-up Horizontal trolley, gravity mass
14 Take-up travel distance 14,0m live; 19,0m available
15 Take-up mass 19,4 tons
16 Belt sag 1% to 3%
17 Installed power Head=2x500kW; Tail=1x500kW
18 High tension and drive pulley diameters  1000mm
19 High tension pulley face width 1900mm
20 Gearbox ratio (norminal) 17,73 : 1
21 Type of reducer Elecon Helical gear
22 Motor type GEC - Alsthom Frame DC355F900R 
23 Motor shift speed 0 1490rpm
24 Type of high and low speed couplings Flexible geared couplings
25 Low tension / take-up pulley diameter 800mm
26 Low tension pulley face width 1900mm
27 Idler diameter 152mm
28 Idler gauge length 325mm
29 Number of idlers per panel 12 off
30 Pitch of idlers straight sections 2000mm
31  Pitch of idlers curved sections 1000mm
Birla Copper Pipe Conveyor - Photos

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View from head end into curve
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View of pipe opening at head end
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View of pipe curve
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View of pipe curve
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View of belt curve from tail
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View of panel layout
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View of vertical curve layout
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View of carry side pipe forming
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View of carry side pipe forming