Robust drive systems for reversing rolling mill in the desert

Heavy loads, frequent severe shocks, extreme temperatures – reliable drive operation is challenging in a rolling mill in Bahrain. NORD provided robust and flexible solutions for systems engineered by SMS Meer.

Focus on the Customer
SMS Meer is a world leader in heavy machinery and plant engineering for the steel and metals industry. A business division of SMS group, SMS Meer focuses on continuous casting technology, long products plants, tube and pipe plants, forging plants, nonferrous metals plants, and heat treatment technology in steel plants. For the steelworks project in Hidd, the German company collaborated with SMS Concast, another member of the SMS group.

Focus on the Project
The reversing rolling mill in Bahrain uses 622 roller table drives and a number of other NORD drive solutions, including large industrial gears in a straightening machine for the rolling stock. These systems fulfill demanding functional requirements in tough conditions due to their

  • resilient single-piece housings that ensure a long lifespan,
  • superior quality gear teeth precisely machined by NORD,
  • design flexibility, e.g. for optional shafts on both sides.

Project Challenges
In recent years, a great integrated steelworks complex was erected in the Hidd industrial zone in the Kingdom of Bahrain. Its annual production of some 600,000 t of steel per year is to cover one sixth of all previous beams and sections imports of the entire Middle East. As part of the Hidd complex, steel industry plant engineering specialist SMS Meer designed and installed a heavy section rolling mill with state-of-the-art equipment.

Rough conditions. – The plant required scores of geared motors designed to handle the typical load cycles in rolling mills, notably S5 intermittent duty as well as S9 duty with non-periodical load, speed variations, and frequent overloads. 16 t beams pass on roller tables through the reversing mill. The many drives installed along these tables must cope with the shock impact of alternating acceleration and deceleration of the blanks. Moreover, the roller table drives in Hidd are faced with especially high ambient temperatures due to the climate of the Gulf state.

Standard systems preferred. – SMS Meer also needed other highly resilient and powerful drive solutions for additional machinery, e.g. for a straightener with double-supported rollers that relies on hydraulic adjustment. The engineering company was determined to limit special gear solutions to a minimum, and therefore required a comprehensive portfolio of gears for implementations using standard units in as many cases as possible. Finally, SMS Meer asked for particularly high flexibility of use for a number of specific drive systems.

Application Solution
NORD supplied drive systems featuring an extremely robust design: encased in single-piece housings, gears with helical teeth flanks machined and finished to exacting standards provide superior stability even under high radial and axial loads. Even greater resilience and durability can optionally be achieved by using reinforced shaft material (e.g. 42CrMo4) and stronger bearings. In addition, shock-absorbing housing materials can help reduce the impact of abrupt rough movements. Special synthetic lubricants (ISO VG220) and special coatings are available to adapt to extreme ambient and operating temperatures.

Versatile to use. – In addition to over 600 roller table drives, SMS Meer also uses other NORD systems. These include standard parallel shaft gears for chain conveyors at the cooling bed, where they replace special gears previously needed in this type of application. Four high-torque industrial gears for straightening the heavy blanks in front of the rollers were fitted with input and output shafts on both sides, and therefore can be operated either way. For these industrial gears, special output shafts with suitable borings were equipped with encoders supplied by SMS Meer.

Extensive industry expertise. – NORD has been collaborating with SMS Meer for more than a decade in numerous projects. NORD provides versatile steel and metals industry drive solutions for applications ranging from roller tables to cooling beds, from shear lines to casting ladles, and on to various other segments of the production process.