In 2012, we supplied two type ZH 15000 oil-free centrifugal turbo compressors, including dry coolers and pumps, for a new cooling-water circuit at the Swiss chemical group EMS-Chemie. Our units provide compressed air for air supply and nitrogen production at the Domat/Ems production site – with astonishing results.
The high-performance polymer specialist, whose products are used for the automotive and mobile phone industries, presented us with an ambitious challenge. The compressed air supply for the plant air and the air separation system needed improving, while the new compressed-air unit required a new cooling system.
The challenge was to carry out the work without a moment’s interruption of production.
The needs at the Domat/Ems production site are enormous. Every year 74,000,000 Nm3 of compressed air is required for the plant air supply and 69,000,000 Nm3 for the production of nitrogen. In 2010 it became apparent that the existing systems would be unable to meet production requirements much longer.
When one of the 6 compressors broke down, EMS-Chemie engineers questioned the existing concept and started research for the planned capacity increase. They came up with a redesign of the entire system and contacted us for a tailor-made solution.
The existing unit consisted of 2 turbo compressors and 4 old oil-free reciprocating compressors that supplied the 2 compressed-air networks operating at different pressure levels. The 2 ZH turbo compressors, one from another supplier and a type ZH 10000 geared turbo, were retained to ensure security of supply; and because they complemented the 2 new type ZH 15000 geared turbo compressors.
The 2 new compressors supply both the plant air and the compressed air for the nitrogen production at different pressure levels in an optimal range. Furthermore, the plant air network was expanded with an additional adsorption dryer to meet the increasing requirements for compressed air. The engineers were tasked with accomplishing the changeover without shutting down production, which was successfully done thanks to meticulous planning and precise execution.
The first step was to install a new, closed cooling-water circuit with a dry cooling capacity of 3 MW and then to lay the new pipework system in the central compressed air unit. The new compressed-air unit was set up alongside the old compressors.
We prepared a complete parallel system and then swapped over the unit, one machine at a time, ensuring that round-the-clock production was maintained. We had an outstanding partner who always came up with a solution when we encountered problems.
The state-of-the-art central compressed-air unit ZH 15000 helped EMS-Chemie achieve a saving in electricity consumption of 10%. The new cooling water system has reduced water usage by up to 75%.
The question of energy usage was our prime concern, and here, too, we are more than satisfied. The ZH 15000 produces less waste heat and consumes less energy with the same output. Their energy efficiency is simply better. That is exactly what we needed.