Atlas Copco oil-free compressors provide energy-efficient air at major aluminum plant

Established in 2005, Henan Wanji Aluminum Co., Ltd. (Wanji Aluminum) is one of the largest aluminum smelters in China. The company uses the Hall-Heroult method to process the alumina, which is separated into components of aluminum metal and oxygen gas by electrolytic reduction. The facility has two electrolytic aluminum production lines with a total production capacity of 650,000 tons per year. Compressed air is widely used throughout Wanji Aluminum’s plant for processes such as conveying alumina to the silo and from the silo into the pot lines, carbon anode production, air instrumentation and pneumatic conveying of recycled particulate. To meet their compressed air requirements, Wanji Aluminum employs five ZH 15000 and five ZH 10000 oil-free centrifugal compressors.

ZH centrifugal compressors are designed to maximize uptime and minimize maintenance resulting in energy savings. Milled impellers made from stainless steel 15-5 PH, spin tested at 115% of the nominal speed, ensure zero defects. Variable geometry flexible pad bearings, carbon ring air seals, labyrinth oil seal, AGMA Class A4 gears and stainless steel coolers contribute to trouble-free performance and long operating lives. The horizontally split gearbox makes access for inspection and preventive maintenance easy and quick. Energy accounts for one-third of aluminum production expenses, so significant energy can be saved during the initial selection of a compressed air system. The majority of the components on the ZH compressor are specifically designed to optimize energy efficiency, and the entire unit is measured according to ASME PTC10. The oil-free turbo core unit provides the optimum combination of high flow with low energy consumption. Ample sized cooling, low pressure drops and an efficient drive drain result in high compressor package efficiency. In the aluminum production industry, compressed air is used for pneumatic transport of raw aluminum powder. Oil contamination can cause quality defects and pipe clogging, as well as pose a fire hazard. ZH compressors provide 100% pure, clean air that complies with ISO 8573-1 CLASS 0 (2010) certification. “In production, we use a large amount of compressed air for instruments and raw material conveying. To reduce production costs and improve end product quality, we chose the efficient and reliable compressors,” said Mr. Bai Xiao Jun, Process Manager at Wanji Aluminum. “Atlas Copco is a qualified supplier and its air compressor equipment has displayed excellent performance and super high stability since it was put into use, which is the key to our choice of Atlas Copco.”. Written by Lynn Lin