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.

Sven Breit­feld is delighted that he has only one contact partner for cooling towers and bottling systems: Krones. (Photo | Ralf Kreuels)

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

The cooling towers ensure the process reli­a­bility required for bottling as optimum quality can only be achieved with reli­able cooling capacity. (Photo | Ralf Kreuels)

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.

Chris­tian Depner from Product Treat­ment Tech­nology at the Krones site in Flens­burg (Photo | Krones)

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.”

The reac­tive power of the cooling towers is minimal. If the temper­a­ture changes, the power of the fans that temper the water by supplying air is auto­mat­i­cally adjusted. Here Krones relies on AxiBlade EC fans, which are ideal for demand-based cooling capacity thanks to step­lessly vari­able control. (Rendering | Krones)

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.

Five AxiBlade fans from ebm-papst run in each of Line 8’s cooling towers. The AxiBlade axial fans are also equipped with special corro­sion protec­tion. (Photo | Ralf Kreuels)

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.”

In Sittard, Refresco fills 400 million cans every year on Line 8 from Krones. The line was put into oper­a­tion in 2019. (Photo | Ralf Kreuels)

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.”