Overland Pipe Conveyor

Conveyor Belts: Save Energy by Minimising Belt Rolling Resistance

Page: 5/5

Energy Efficient Operation of Long Overland Pipe Conveyors

The LRR belt can achieve significant energy savings for pipe conveyors. Using the Kailin conveyor as an example, based on the 3.2 million metric tons annual tonnage, the current LRR belt will save about 4 million kWh per year compared to the conventional pipe belt. Accumulating over the belt life, the energy saving can be comparable to the belt cost itself.

The additional power consumption for pipe conveyors, compared to trough conveyors, mainly comes from the extra contact pressure between pipe belts and idlers. As a result, the power consumption for running an empty pipe conveyor is high, compared to the full load condition. To minimize the power cost, empty running should be avoided, unless for maintenance purposes.

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Although same is true for trough conveyors, avoiding empty running for pipe conveyors has stronger effect on operating cost. With Variable Frequency Drives, the power consumption can be reduced by adjusting the belt speed depending on the material load, while keeping the same material cross section. Keeping the material cross section constant can also increase the pipe belt stability and reduce belt rotation. For long overland pipe conveyors, this can be achieved with a silo or stockpile at the tail, weight scales near the loading point, and VFD’s PLC control logic to adjust belt speed based on material loading.

4 Conclusion and Acknowledgements

Long overland pipe conveyors can transport materials in enclosed pipe belts and have small radii curves. However, the power consumption is typically double compared to trough conveyor, incurring high capital and operating cost. Low Rolling Resistance (LRR) trough belt is a well-studied and proved technology. By combining numerical modeling and experimental testing, the LRR pipe belts can be analyzed to optimize the design and operation of long overland pipe conveyors, and the benefits of which have been validated through several conveyor projects.

The author thanks Robin Stevens, Mingya Tang, Shannon Willer, Bruno Torchio, Kevin Xie, Doug Gilg, Dave Maguire and the team at Veyance Technologies, Inc., Marcelo Gelais and the team at Tecnometal Engenharia, Tunra Bulk Solids at University of New Castle, Australia, and colleagues at Conveyor Dynamics, Inc., for their contribution and support. n

References

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[2] Stevens, R.: Belt conveying-belting the worlds' longest single flight conventional conveyor. bulk solids handling, Vol. 28 (2008) No.3.

[3] Hager, M., Hintz, A.: The energy-saving design of belts for long conveyor systems. bulk solids handling, Vol.13 (1993) No. 4.

[4] Wheeler, C., Roberts, A., Jones, M.: Calculating the flexure resistance of bulk solids transported on belt conveyors, particle and particle system characterization. bulk solids handling Vol. 21 (2004) No. 4.

[5] Nordell, L.: The power of rubber. bulk solids handling, Vol.16 (1996) No. 3.

[6] Kruse, D.: State-of-the-art data acquisition equipment and field measurement techniques for conveyor belts. In: Reicks, A., Myers, M.T. (ed.): Bulk material handling by conveyor belt 5, SME, Littleton 2004.

[7] Zhang, A.: Pipe conveyor and belt: belt construction, low rolling resistance and dynamic analysis. SME Annual Meeting 2012, Seattle (WA), USA.

* Dr. Yijun Zhang, P.E., Technical Director Conveyor Dynamics, Inc., USA.

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