Article by John Butterfield
At its Ahaus site, GEA produces not only milk and juice processing systems but also heat exchangers for heating and cooling in aseptic procedures. They are at the heart of all processing systems for heating, cooling, pasteurising or UHT heating. The brewery and beverage industries are typical applications for GEA heat exchangers where they are used for wort cooling/heating, flash pasteurization of beer and yeast, and the heating and cooling of wine. Users can choose from a large number of different heat exchanger designs, depending on the required production capacity and the physical properties of the product. GEA also develops customised designs on request to suit each specific application.
Regardless of the individual application, all heat exchangers function according to the same principle: the product flows through several straight inner tubes with a heat transfer medium flowing around them in a jacket tube. This structure equalises the differing heat expansion rates between the inner tube package and the jacket caused by high differences in temperature.
High demands of the Pressure Equipment Directive 97/23/EC
All heat exchangers have to fulfil the strict conditions imposed by the Pressure Equipment Directive 97/23/EC. GEA was therefore looking for a reliable supplier of top quality longitudinally welded stainless steel tubes for use as product-conveying inner tubes fitted inside the heat exchangers. “We know exactly what we need in terms of the tubes used in our aseptic systems”, explains Christoph Oberrecht, purchaser PSC EMEA Central Procurement at GEA. “In addition to high quality and the right value for money, it was also important for us to find an appropriate concept for the logistics. Schoeller Werk is the right partner to meet both of these requirements.
Stainless steel tubes pursuant to food industry standard Since 2016, the industrial plant manufacturer in Ahaus has been the customer of the specialist for longitudinally welded stainless steel tubes from Hellenthal (Eifel). Schoeller Werk produces stainless steel tubes pursuant to the food industry standard DIN EN 10357 BC and supplies them according to demand on the basis of a refined logistics concept. The DIN EN 10217-7 compliant tubes made of austenite 1.4571 fulfil the Pressure Equipment Directive 97/23/EC. The tubes in the heat exchangers are in direct contact with the product and therefore also fulfil the special hygiene requirements imposed by the food and beverages industry, including among others a weld factor of 1.0 and tube roughness of < 0.8 my They are therefore also certified with certificate APZ 3.1 B pursuant to DIN/ EN 10204.
Schoeller Werk supplies the tubes in a variety of dimensions. “The special thing about our collaboration with GEA is the logistics concept which has been drawn up together with the customer”, explains Nathalie Türffs, Head of Sales Industry II at Schoeller Werk. “We plan the production quantities according to demand. These are checked on a monthly basis, and safety stocks are taken into storage in quantities agreed with the customer.” That is a great advantage for GEA as it saves storage costs. Furthermore, it also puts the company in a position to respond to short-term project business and the resulting fluctuations in demand. “Production of the tubes would take several weeks”, explains Christoph Oberrecht, purchaser at GEA. “In the framework of the logistics concept, the tubes are supplied usually just a few days after placing our purchase order. It helps of course that Schoeller Werk in Hellenthal is not far from our Ahaus site.”
GEA’s customers benefit from the extremely high quality of the heat exchanger systems, thanks primarily to the inner tubes made by Schoeller Werk. For the contact persons at GEA, the specialist for longitudinally welded stainless steel tubes is more than just a supplier. As a well established company that looks back on a long tradition, Schoeller Werk also offers swift service and support, dealing reliably with any technological issues covering all aspects of the tubes. “Schoeller Werk fulfils all our requirements for top quality stainless steel tubes. It should also be said that our contact persons at Schoeller Werk always deal promptly with our concerns and enquiries to our utmost satisfaction”, says Christoph Oberrecht. «