Increasingly stringent environmental legislation and regular increases in electricity tariffs continue to burden industrial operations. Blower and compressor specialist, Airgas Compressors offers relief in the form of internationally recognised energy efficient motor technology which ensures measurable power savings. According to Airgas marketing co-ordinator, Andreas Stubel, the biggest cost factor of owning a compressor is its energy use.
“The energy costs involved in running a standard compressor over its lifetime far outweigh the initial investment and maintenance costs. The most effective means of reducing operational costs is, therefore, through optimised energy use,” he says.
It has been estimated that electric motors around the world consume between 30 and 40% of all electricity produced. In order to optimise electric motors, international regulatory organisations have introduced various standards. The most familiar is the IEC 60034-30:2008 standard set by the International Electrotechnical Commission (IEC). The IEC has focused on single-speed, three-phase, 50 Hz and 60 Hz AC cage induction motors in the most widely used range of 0,75 to 375 kW. According to this standard, motors are produced and categorised as IE1 – standard efficiency, IE2 – high efficiency and IE3 – premium efficiency. IE4 is in development but this is still some time away.
The IE1 motor is less efficient in comparison to an IE3 motor and the core difference is in the materials used during manufacturing. The most obvious difference is the physical size of the different motors. IE3 motors are larger and heavier than IE2 or IE1. Stubel explains that IE3 motors are so efficient due to a combination of factors including a higher mass of copper coil with thinner laminations, improved cooling fan and the use of special bearings. “Increasing the mass and cross section of copper in a coil increases the electrical energy efficiency of the motor. IE1 and IE2 motors are common in South Africa, while IE3 is seldom seen. IE3 motors will become mandatory by 2015 in countries such as Germany,” he adds.
Although IE3 motor efficiency is commonly used in the European and North American marketplace, Stubel admits that it is still in its infancy in South Africa. “Although the idea of energy efficiency is becoming more common, the process of implementation is a long and complex one. Mindsets are slowly changing, and energy efficiency will become increasingly important in the near future with energy costs rising at such a rapid rate.”
Stubel acknowledges that the initial purchase cost of IE3 premium efficiency motor technology is high, however he stresses that the long-term environmental and capital savings of the new technology far outweigh the initial cost difference. He says that another approach to improve the efficiency of motor systems is through the use of variable speed drives that regulate the speed of the motor, and reduce energy usage.
He adds that regular maintenance is another method of reducing energy consumption while increasing productivity. “Effective maintenance does not only entail individual components, but rather looks at the entire system and its performance as a whole. It is important to first establish the current condition and inefficiencies of the system by gathering operating data before assessing the energy consumption of the system and looking at future production needs,” he says.
Airgas is the sub-Saharan subsidiary of German-based Aerzener Maschinenfabrik, a specialist in the design and manufacture of roots blowers, turbo blowers, screw compressors, rotary lobe compressors and gas meters. The Aerzen Delta Screw Generation 5 Plus compressor model has been updated specifically to be more energy efficient by manipulating components for enhanced cooling and improved gas compression. Together with IE3 motor technology, it is by far the most energy efficient screw compressor on the market today.
The Delta Screw Generation 5 Plus is an oil-free, belt driven machine and is available in seven sizes with volume flows from 120 to 2650 m³/h, and pressure ranges between 2 and 3,5 bar. This can be extended to 15 000 m³/h with Aerzen’s Delta Screw range of direct drive compressors. These compressor packages are designed for compressing air, nitrogen and other neutral gases.
“As these are positive displacement machines, the volume throughput is directly proportional to the speed at which it runs, making the Delta Screw Generation 5 Plus ideal for operating in different ranges, which can be optimised via variable speed drive,” Stubel continues.
Looking ahead, Stubel is confident of the future outlook for energy efficient compressor technology locally. “Energy efficiency in Africa still has a long way to go, but we are confident that we can satisfy future demands for efficient compressors as the market becomes more accustomed to the long term benefits of such technology,” he concludes.
For more information contact Andreas Stubel, Airgas, +27 (0)11 474 2193, [email protected], www.airgas.co.za
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