They call themselves the “Kings in Cans” — and the approx. 400 employees at the Refresco site in Sittard, Netherlands, are not exaggerating when they say this. Every day around four million cans whiz across numerous conveyor lines here through various bottling plants. They are filled with energy, sports and refreshment drinks or beer, and then end up on the shelves of renowned food chains and discount stores worldwide.
Each year 400 million cans alone pass through the new Line 8, which Refresco procured from Krones and was started up in 2019. The special thing about it is that the turnkey line is one of the first bottling plants that Krones supplied with a self-designed cooling tower. Sven Breitfeld, Production Process Manager at Refresco in Sittard, explains: “We were already using several individual machines and another turnkey line from Krones. For us, the new complete system is advantageous because we only have one contact partner for it. This simplifies a lot of things. Like us, Krones is committed to constantly improving products and optimizing them through innovation. The cooling towers tailored to the plant are a good example of this.”
With a turnover of around 2.3 billion euros, the Refresco Group, which is headquartered in Rotterdam, is the world’s largest independent bottling company for retailers and branded beverage companies in Europe and North America. With 61 sites around the world, the company does justice to its motto of “Our drinks on every table.” Across the whole company, around 30 million liters of drinks from different manufacturers are produced and bottled every day — including fruit juices, iced teas, energy and sports drinks, mineral water, beer, and much more.
Sven Breitfeld: “We offer our customers innovative production and bottling solutions, along with a high level of quality. But we are also aware of our responsibility as a market leader. We have a comprehensive sustainability strategy, which includes energy-efficient production and we work together with partners who offer the right solutions.”
A cool decision
One of these partners is Krones, the bottling and packaging specialist headquartered in Neutraubling, Bavaria. For years, developers here have been working intensively on resource-saving and energy-efficient solutions for the industry. The world market leader has considered itself more than a mechanical and plant engineering company for a long time now. The company invests around five percent of its annual turnover in research and development, and currently has around 6,000 patents.
It is no surprise that the plant developers were itching to investigate the emerging cooling tower market. Previously, Krones had only purchased cooling towers. But the product is hot property: Whilst in recent years refrigerating plants or fresh water have still mainly been used for cooling in production, the demand for cooling towers as an additional component is constantly increasing.
Cooling towers form a second cooling circuit within a bottling plant. First of all, the filled cans or bottles are showered with cold water following pasteurization. This water is cooled by refrigeration plants or cooling towers depending on the temperature level. The energy expelled for this is optimally used with the help of recuperation cycles. If a recovery cycle stops in certain operating states, working heat develops that has to be dissipated quickly because it can affect the appearance and taste of the products.
This is where the cooling tower comes into play, explains Christian Depner from Product Treatment Technology at the Krones site in Flensburg: “It takes over the cooling to a certain level, and is much more economical than the refrigerating plant in the process.”
It was therefore obvious for Krones to expand their already extensive portfolio with this promising component. Of course, with a version optimized for processes, completely in line with the perfectionism of the company.
Perfectly coordinated solution
The specialists at Krones incorporated their pooled expertise for the cooling towers. The earthquake-proof stainless steel construction is welded instead of having screws, and is designed in such a way that it provides bacteria with as little contact area as possible. Christian Depner helped with the process engineering-based design of the cooling capacity. He explains: “Four years ago, as a student trainee, I dealt with the design of cooling towers in my Bachelor’s thesis. A calculation basis was already there, but we also took some additional factors into account that illustrate the reality of our sector even more accurately.”
Using process expertise to make their own cooling tower
One important factor is the location of the plant, for example: The temperature and humidity of the ambient air have a major influence on the cooling capacity that can be provided for production. In the different areas of the bottling plant, there are also heat-generating energy peaks at certain times during the process. These briefly require a higher cooling capacity, but this can be reduced after a certain period.
Seasonal adjustment of the cooling capacity is just as important as when changing the product. Christian Depner explains: “If for example juices are bottled hot, short and intense cooling is required. Other liquids, by contrast, require even cooling over a long period of time.”
Years of experience with production processes and products, as well as the extensive expertise at Krones, made it possible for all relevant factors to be taken into account. This has enabled the reactive power of the cooling towers to be reduced to a minimum. To ensure that only the required cooling is available at all times, the cold water flow that leaves the cooling tower is continuously measured.
As soon as the temperature changes to a minimal extent, the power of the fans that temper the water by supplying air is automatically adjusted. This means that the required power is always available, while the customer benefits from less noise and significantly reduced energy consumption.
So that the system functions as required, the fans fitted need to be precisely controlled. They are an essential component of a cooling tower. This is why Christian Depner left nothing to chance here: “We looked at various options and then decided on the AxiBlade series from ebm-papst. Thanks to EC technology, the fans can be steplessly powered up and down, thereby always providing demand-based cooling capacity.”
“We have a comprehensive sustainability strategy, which includes energy-efficient production.”
Sven Breitfeld, Production Process Manager at Refresco in Sittard
Before the fans were used, the developers made important adjustments. Depner explains: “The fans come into contact with aggressive biocides that suppress algae and legionella growth in the water circuit. ebm-papst therefore provided all the AxiBlade series we needed with special corrosion protection. Because we use a control signal of 4 to 20 milliamperes as standard in our systems, ebm-papst also provided us with a special parameterization with the appropriate input.”
More fans = greater process reliability
Depending on the required cooling capacity, between one and eight fans are generally used in a cooling tower. Two cooling towers, each with five fans and a total thermal output of 1,940 kilowatts, are installed in Line 8 at Refresco. Christian Depner explains: “The fans run at an average of 50 percent load. The advantage of multiple installed fans is definitely process reliability. If one fails, the others can be easily ramped up and the cooling capacity maintained.” This bonus in terms of reliability is also important for Production Process Manager Sven Breitfeld: “We need systems that run with complete reliability, guarantee the optimum quality of our products, and fit our sustainability strategy.”
Krones has since built 37 cooling towers and supplied companies in Germany, the Netherlands, Brazil, Hungary, and Africa, among other places. There is a high demand for energy-saving technologies. Sven Breitfeld also sees the Neutraubling-based company as being on the right path: “To us, Krones is a competent contact partner who is also familiar with third-party machines in our lines. The option to now purchase everything, including the cooling tower, from a single source, makes Krones an even more attractive partner for us.”