DRIVE TECHNOLOGY Robust
DRIVE TECHNOLOGY Robust drive technology for steel rolling mill in Bahrain Two international players with their home bases in Germany have successfully completed a project that will serve a vital role in Bahrain’s construction industry. Using drive technology from Nord Drivesystems, steel industry specialist SMS Meer has built a new heavy section rolling mill on the desert island. Only the most resilient electric drives withstand the severe mechanical stress and extreme heat, dirt, and steam. About Nord Drivesystems A developer and manufacturer of drive technology for over 50 years, Nord Drivesystems employs more than 3,200 people and is one of the world’s leading suppliers of full-scale, comprehensive drive solutions. The company’s portfolio ranges from standard drives to customized solutions for demanding application requirements. Gross sales currently amount to some € 500 million p.a. With subsidiaries in 36 countries and an extensive distribution network, the company based in Germany ensures a minimal lead time and provides customer-oriented services wherever needed. Nord’s wide variety of gear types covers torques from 10 Nm to 242,000 Nm and more. The company also supplies motors with outputs from 0.12 kW to 1,000 kW and manufactures frequency inverters up to 160 kW. The Kingdom of Bahrain is pushing for the development of domestic manufacturing facilities. A huge integrated steelworks complex in the ‘Hidd’ industrial zone is to supply enough steel products to replace almost one sixth of all imports of beams and sections into the Middle East. As part of this new complex, German heavy machinery and engineering specialist SMS Meer designed and installed a heavy section rolling mill. The project’s principal and local operator is the United Steel Company ‘SULB’. In order to quickly achieve the ambitious objective, i.e. to satisfy a sizable portion of the Gulf states’ steel demand from within the region, the mill boasts an initial capacity of 600,000 tonnes per year. The drives in these installations are not only faced with the demanding operational requirements found in all rolling mills, but also with the extreme climatic conditions of the Middle East. Working with SMS Meer, Nord Drivesystems was able to provide a broad range of extra resilient solutions comprising more than 600 roller table drives plus other units, including several special-purpose industrial gears. Rough conditions for conveyor technology An endless stream of 16 tonne beams passes through the reversing mill. The drives installed on the roller tables must cope with the shock impact of alternating acceleration and deceleration of these blanks. “This is extraordinary mechanical stress, too much to handle for run-of-the mill geared motors,” says Guido Sonnenschein, drive expert at SMS Meer. “Consequently, drive systems for roller conveyors have always been a case for a handful of specialized manufacturers. And it definitely helps to have a broad selection of suitable drive models to choose from, which makes it possible to implement the best solution for every application.” Nord Drivesystems has a long history of collaboration with SMS Meer in numerous projects. “SMS Group and Nord look back on some ten years of joint experience,” says Sonnenschein. “From the very beginning, Nord was a preferred partner due to their extraordinary broad and varied range of gear models. We find their in-depth expertise for steel industry drive solutions to be indispensable.”
01 02 01 Nord gears featuring a single-piece housing ensure minimal wear and tear for excellent reliability and durability 03 02 Heavy blanks arrive on Nord-driven roller tables at the rolling stand, where powerful industrial gears from Nord properly align them for a pass under the rollers 03 In addition to a large number of gears for roller drives, several Nord industrial gears as pictured above were also supplied for the Hidd project in Bahrain Robustness and longevity are crucial factors In addition to the sudden jolts and heavy loads in the conveying applications, high ambient temperatures complicate the operations in Bahrain, where +50 °C are common. A highly resilient design enables the roller table drives to withstand such demanding conditions. Nord gears generally feature a single-piece housing that provides for high radial and axial load tolerance. All helical teeth flanks in the gears are machined and finished to exacting standards, which further ensures the gears’ extreme stability under load. Even greater resilience and durability can optionally be achieved by using re- inforced shaft material (e.g. 42CrMo4) and stronger bearings. Shock-absorbing housing materials can also 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. For steel mill roller tables, the longevity of drive systems is paramount, since steel plants typically remain in operation for decades, and operators expect components that must only very rarely be replaced. “Of course, our roller conveyors are built in such a way that they will perform for many years with minimal maintenance requirements,” says Thomas Danne, Project Manager Electrics & Automation at SMS Meer. “But just in case, it is good to know that a drive supplier like Nord is always there to provide parts and service personnel on short notice, basically anywhere around the world.” From customized to standardized components The 622 auxiliary drives for roller tables were not the only solutions SMS Meer sourced from Nord for the heavy section mill. Danne says, “Of course, sometimes there were certain modifications and we requested a few extraordinary gear ratios. Mostly, however, Nord’s flexible modular construction system has allowed us to choose a standard drive – despite the great number of different models we needed. And this did not only apply to the roller table drives. This was the first time that we did not need any special gears for the cooling zone’s chain conveyors. We used to provide dedicated in-house solutions for this part of the plant. Now, we were able to install four of Nord’s standard parallel shaft gears instead.” Some gears for SMS Meer are particularly versatile – these include four high-torque industrial gears for orienting the heavy blanks in front of the rollers. These units were fitted with input and output shafts on both sides. The side not in use is fitted with a protective cover. In these units, special shafts with suitable borings were equipped with encoders supplied by SMS Meer. Unlike other manufacturers, Nord provides a full range of industrial gears in single-piece housings – even very large 242,000 Nm models. In contrast to multi-piece constructions, the ‘Nord Unicase’ design is much less susceptible to torsional damage, even at maximum load. With the successful completion of the project in Bahrain, SMS Meer and ‘Nord’ are now determined to strengthen their existing co operation even further in anticipation of new forthcoming joint endeavors. Versatile metals industry drive solutions In terms of functionality, the drives in steel mill applications have to fulfill dynamic tasks in typical load cycles, notably for S5 inter mittent duty as well as for S9 duty with non-periodical load, speed variations, and frequent overloads. Answering these challenging demands, Nord Drivesystems provides a flexible drive solution for all processes in the metals industry, based on a versatile portfolio of gears, a line-up of ‘TENV’ (IC 410) and ‘TEFC’ (IC 411) motors with straight fins or ring fins, and frequency inverters for cabinet install ation or mounting close to the motor. Options such as integrated brakes and heavy-duty incremental encoders are available as well. Large industrial gears are available for casting ladles and other applications requiring especially powerful drive solutions. Nord is the only manufacturer to offer even 242,000 Nm industrial gears in single-piece ‘Unicase’ housings. Photographs: Nord Drivesystems www.nord.com MDA Technologies 1/2016 33
