The compressors are also connected to a heat recovery system, thereby reducing electricity costs even further.
Preforms made of polyethylene terephthalate, better known as PET, are blown into drinks bottles using the stretch blow molding method, which requires a lot of compressed air and a high level of pressure. The compressed air supply at Schwarzwald-Sprudel in Wildberg is based on three ZR screw compressors, two of which are equipped with speed regulation (VSD Variable Speed Drive), as well as two speed-regulated boosters. These components supply the two bottling lines with compressed air. The scale of the system is illustrated by the fact that there is almost 1000 kW of installed power even if the machines never run all at the same time.
Oil-free compressed air guaranteed
The compressed air for the stretch blow molding process is first compressed to around 8.5 bar by a screw compressor, before being further compressed to 29 bar by one of the boosters. All of the components used to produce compressed air operate entirely without oil for example, the DN 160 type booster piston compressor and the ZR screw compressors both deliver oil-free air in accordance with ISO 8573-1, Class 0 (2010). An ES 130 energy-saving system controls the entire compressed air system in such a way that the compressors run as closely as possible to their optimum operating point, in particular the speed-regulated compressors. “We set the system in such a way that, for six months of the year over winter, it is primarily the new ZR 250 VSD-FF with heat recovery that is running in this way, we are able to reuse as much heat as possible for heating tasks,” emphasizes Bernhard Griesau, Plant Manager. In addition to the abbreviation VSD for speed regulation, the FF (Full Feature) in the compressor name stands for a range of equipment from the factory that comprises all the key components for compressed air treatment right through to heat recovery, meaning connection could not be simpler.
Sustainable energy management with heat recovery
Heat recovery forms part of a sustainable energy management strategy. The general idea is that the power absorbed by the compressor during compression is converted into heat. This heat can be almost entirely recovered and used for heating water. “We use this method primarily to support the heating in the halls and, to a lesser degree, to heat process water,” continues Griesau. When it comes to servicing the compressed air production system, Schwarzwald-Sprudel relies on the premium maintenance agreement from Atlas Copco. In addition to the necessary inspections and maintenance, this agreement also comprises free repair for any damage that occurs, up to and including a complete general overhaul.
Schwarzwald-Sprudel was founded in 1950 at the Tannenhof site in Bad Griesbach, the company’s present-day headquarters. In early 2007, Edeka Südwest from Offenburg, Germany, took over the parent company in Bad Griesbach and integrated the Schwarzwald spring in Wildberg founded as the Wildberg branch in 2002. The plant currently employs 60 people on the two bottling lines, who fill approximately 160 million PET bottles each year with volumes of 0.5, 0.75 and 1.5 l.
Atlas Copco’s Compressor Technique business area provides industrial compressors, vacuum solutions, gas and process compressors and expanders, air and gas treatment equipment and air management systems. It has a global service network. Compressor Technique innovates for sustainable productivity in the manufacturing, oil and gas, and process industries. Principal product development and manufacturing units are located in Belgium, Germany, the United States, China, India and Korea.
Atlas Copco (atlascopco.com) is an industrial group with world-leading positions in compressors, expanders and air treatment systems, construction and mining equipment, power tools and assembly systems. With innovative products and services, Atlas Copco delivers solutions for sustainable productivity. The company was founded in 1873, is based in Stockholm, Sweden, and has a global reach spanning more than 170 countries. In 2012, Atlas Copco had 39 800 employees and revenues of BSEK 90.5 (BEUR 10.5).