During a programme of expansion, a Hungarian steel mill needed 350 couplings which could withstand heat and contaminants on a new hot-strip runout table, designed to transport heated steel around the plant

Steel mills are notoriously harsh environments, with the equipment installed within them needing to withstand not only hot temperatures but also contaminants. So when a Hungarian steel mill needed nearly 350 couplings for a new hot-strip runout table it was installing during a period of expansion, it turned to Altra Industrial Motion for a suitable solution.

The 505ft hot-strip runout table would be used to transport extremely hot metal around the production plant and is expected to help the steel mill to increase its throughput from 1.8 million tons to three million tons each year. It would, in fact, be responsible for transferring over 8,000 tons of steel every day, and a failure would create a bottleneck throughout the whole site which would slow production.

The runout table would be equipped with 337 6ft wide, 12in diameter, stainless steel rollers, driven by 7.5kW motors at 900rpm. Each roller, however, needed to be fitted with a coupling that would continue to transfer the power from the motors efficiently despite the harsh operating environment and the possibility of small degrees of misalignment. In addition, not only did the couplings have to be capable of withstanding the environment, but they had to be easy to install and maintain in order to keep running costs to a minimum.

Having looked into the options, it was decided that DuraFlex couplings from TB Wood, part of Altra Industrial Motion’s industrial couplings division, would suit the demands.

Power transfer

DuraFlex couplings uses a polyether urethane material to transfer power to a driven shaft while accommodating misalignment and minimising vibration to prevent damage to the connected equipment. A specialised design reduces stress at the bonding point with the shoe which prevents failure at this point. The material is resistant to water and other chemicals and is suitable for operation in high temperatures.

The couplings have a simpler radial mounting design, rather than axial mounting, and are quick to install. In addition, the ‘split-in-half’ element design allows for easy element installation and replacement without moving connected equipment or disturbing the shaft connection. In the event that a roller needs maintenance, or the couplings need replacing, they are extremely easy to assemble and disassemble.

David Proud, sales director of Altra Industrial Couplings, commented: “We were happy to be able to help the steel mill almost double its annual production facilities. We try to listen to the needs of our customers and tailor our service to their specific requirements. In this case they needed the couplings at very short notice. We were able to reduce our normal lead time of eight weeks down to four to meet with their required deadline.”

Altra Industrial Motion www.altramotion.com