Start of the long belt conveyor in India



imestone is transported from a mine in the Kurmi deposit across the border to the Lafarge Surma Cement Plant. T e conveyor was originally

constructed in 2004 and is one of the longest trans-border conveyors in the world. It covers 10km in Bangladesh and 7km in India. After 11 years in operation, the belt needed to be replaced, and a novel approach was used to replace the 34km of belting. T e Surma plant is the only clinker manufacturing plant in Bangladesh. T e Indian portion of the site is very close to the highest rainfall areas in the world. T e monsoon duration is from May to September with an average monthly rainfall of 1.5m to 2m and the maximum rainfall in a day is around 500mm. T e entire conveyor is raised 5m above

the ground to accommodate the annual fl ooding. T e original annual tonnage for the conveyor system is 2.5 MTPA travelling at a belt speed of 4.0m/s. T e original ST 2500 steel cord belt was supplied by Phoenix in 300m rolls to the Meghalaya site and 500m rolls to the Bangladesh site. 100 splices were required and 80 days to complete the work. To maintain the required cement production at the clinker plant 80 days of downtime to replace the conveyor was not an option.


Fully engineered virtual job planning

Mark Derige & Dr Andrew I. Hustrulid explore a novel approach to changing the belt on 17km conveyor in Bangladesh

Several methodologies for changing out

the belt were evaluated. T e conveyor has seven horizontal curves with radii ranging from 4,000 to 30,000m. T ere are also belt turnovers at both the head and tail of the conveyor. T ere was a concern about the impact of any tension variations. T e entire belt was changed from only the head end in Bangladesh. T e option of using the existing conveyor drives to assist with pulling the belt was dismissed due to the risk of damage which would leave the conveyor inoperable.

AN AMBITIOUS PLAN Almex Group proposed a plan to pre-splice and fl ake out 12km of belting at the head end of the conveyor. T is work would be

done while the conveyor was in normal operation, and not impact production. T e conveyor would then be stopped, the new belt spliced to the old belt, and using powerful belt winders, 12km of old belting would be removed from the system as the new belt was pulled on in a matter of days. T e other end of the new belt would then be spliced to the old belt and the conveyor returned to operation. T e initial plan was to repeat this process a total of three times to replace the 34km of belting. T e force required to pull the 34km of the belting belt during the change out was calculated as 281kN. With two 150kW, powerful belt winders designed and built by Almex Group, the belt was able to be pulled at a controllable speed of 0 to 5m/s.

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