Atlas Copco's ZH compressor plays a critical role at the Solvay hydrogen peroxide factory in Póvoa de Santa Iria, Portugal. When the 80 000-hour unit needed an overhaul that would require it to be out of service for three weeks, Atlas Copco and Solvay technicians developed a plan to complete the maintenance project in nine days of intense work.
Solvay, a global chemical company with 2012 net sales of EUR 12.7 billion, is committed to sustainable development, innovation and operational excellence. The company manufactures a wide range of chemical products for consumers and for industry segments including construction, automotive and energy.
Solvay purchased the ZH oil-free centrifugal compressor 10 years ago. Equipped to save energy and guarantee reliability, Atlas Copco's ZH compressors are good for customer processes with a fluctuating or constant air demand. These compressors provide reliable operation in the most demanding environments. For optimum product quality, air is 100% certified oil-free according to ISO 8573-1 Class 0 (2010).
Overhauling within nine days
As part of its preventive maintenance contract with Atlas Copco, the ZH compressor at the Solvay facility has its rotors inspected and its main components overhauled every 24,000 hours; i.e., every three years. This time the compressor needed to have its rotors balanced. Under normal circumstances, this type of overhaul would take three weeks. However, because the ZH compressor plays such a fundamental part in the production process, the company could not afford to shut it down for so long.
"Thanks to Atlas Copco's flexibility and cooperation, and their awareness of the impact this compressor's absence would have on us, we managed to put together a work plan that allowed us to overhaul the compressor in record time," says Ramiro Dionísio, head of the project at Solvay.
No room for error
In order to complete the overhaul in nine days, the project's schedule allowed no room for error. "Every hour beyond those allocated in the plan was another hour with the process at a standstill, with the consequent loss of production," explains Ramiro Dionísio.
On the first day of work, shortly after the rotors were removed, an international carrier was waiting at the gates to take them to Germany for balancing. "Nobody does this balancing work in Portugal, so the parts have to go directly to the manufacturer," says Ramiro Dionísio. Twenty-four hours later, the rotors arrived in Germany, and in three days the work was completed and the rotors returned to Solvay.
A team of two Atlas Copco technicians and two Solvay employees then reassembled the equipment. "The entire overhaul was completed in nine days. The tenth day was spent monitoring the machine as it went back into production," Ramiro Dionísio says.
Solvay's ZH compressor, which works approximately 8600 hours per year, has supplied compressed air very reliably, robustly and safely, and the final evaluation of the work done on the compressor was very positive. "Let's hope it lasts at least another 80 000 hours," said Ramiro Dionísio.