WCA September 2014

Technology news

How to draw efficiently shaped aluminium wires for HTLS conductors

BECAUSE of increasing electricity demand in many countries, overhead transmission lines are reaching transmission capacity limit and capacity problems of electricity networks are growing. These difficulties can be resolved by upgrading the lines with High Temperature Low Sag (HTLS) conductors which provide many opportunities for the design of conductors and transmission lines with optimum properties. ACSS/TW conductors drawing: The ACSS/TW HTLS conductors consist of trapezoidal-shaped fully annealed aluminium wires (TW), which are concentrically stranded and compacted around a steel support core. These conductors have almost double the current carrying capacity compared to conventional ACSR-conductors with a similar tensile strength and can operate continuously at temperatures of up to 250°C. Maschinenfabrik Niehoff has developed the equipment for the production of the trapezoidal-shaped aluminium wires. An ideal manufacturing line is the electronically controlled MSM 85 type rod breakdown machine combined with an

❍ Electroncially controlled MSM 85 type rod breakdown machine with integrated RA 501 continuous annealer

wire elongations for each draft according to the wires’ material, properties and shapes. Homogeneous wire annealing is guaranteed from zero to full speed operation. Energy savings of more than 20 per cent can be achieved with MSM machines in comparison with rod breakdown machines with conventional drives. Additional features include an optimised wire path, an enhanced wire cooling and lubrication system and a reduced consumption of oil and drawing lubricant. The machines were developed to draw wires made of copper or aluminium, and their respective alloys, as well as other special materials like superconductor wires to a finish diameter from 1mm to 4.5mm.

RA 501 continuous resistance annealer specially designed for the inline annealing of aluminium and aluminium alloys wires. The MSM rod breakdown technology: Niehoff’s MSM rod breakdown technology has been successfully operating in the international wire industry since its market introduction in 1998. The electronically controlled MSM machines, which have seen continuous development since their initial launch, are equipped with the latest controls and drive technology offering users a vast range of benefits in terms of process technology. The controls allow wire drawing with minimal slip, resulting in high quality wire surfaces and a long operational life of the drawing tools. It is also possible to work with different

Maschinenfabrik Niehoff GmbH & Co KG – Germany Website : www.niehoff.de

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Wire & Cable ASIA – September/October 2014