© Gernot Walter

Smoothie in a bottle

Smoothies with pieces of fruit, or dairy products such as buttermilk and yogurt pose no problem for the ProMinent DULCO flex Control peristaltic metering pump. It places the right amount in the packaging, even when it comes to viscose food products – made possible by an EC drive.


ProMinent is a globally established expert for metering technology and water treatment. The precisely controllable diaphragm metering pumps, from the company based in Heidelberg, ensure that the water quality in swimming pools meets the prescribed standards exactly, for example. Peristaltic pumps, on the other hand, convey fluids, even with a high viscosity and strong outgassing, without problem. Just like a tube of toothpaste, the pump keeps pushing the material forward. But what do you do when both skills are required at the same time – metering viscose material with precision? ProMinent developed the DULCO flex Control peristaltic metering pump, which combines both strengths with each other precisely, for this purpose.

In a class of its own

Conveying high-viscosity media with a constant speed, and bottling or decanting it precisely is a real challenge – and not only in the food industry. Thanks to intelligent software, the DULCO flex Control independently controls the metered quantities – in a range of a maximum of 30 liters to a minimum of 10 milliliters per hour. This means it can add precise quantities of color additives or flavoring agents to the food products on their way to the packaging. As the pump can also meter media with gas inclusions without problems, outgassing liquids, such as the disinfectant hydrogen peroxide (H2O2), can be easily conveyed. The peristaltic metering pump simply pushes the air along, too.

The DULCO flex Control peristaltic metering pump from ProMinent can precisely meter viscous material. (Photo | ProMinent)

Spick and span

Pumps with valves or impellers have gaps and other dead space. Often, they have to be disassembled so they can be cleaned to ensure they are germ free. In contrast to this, with peristaltic pumps, the food product only comes into contact with the hose. The food-safe hose can be cleaned and disinfected using CIP (cleaning in place) or quickly changed following a batch change. ProMinent developed a unique process without tools for a quick change: One half of the rotor can be removed so that there is enough space to remove the hose by hand and to insert a new one again. The DULCO flex Control is also cleaning up in another market in addition to the food industry. In water treatment, it adds long-chain polymers to industrial wastewater. The suspended particles grow to a particular particle size and can then be easily filtered out in another process step.

Customized solution

Intelligent software also needs an intelligent drive. The ebm-papst VDC 49.15 brushless DC motor meets this requirement. With integrated control, it aligns with the dynamic adjustment range of the pump. Depending on the metered quantity, the motor turns very slowly to very fast, making the precise metering possible in the first place – and without overheating during continuous operation.

“ebm-papst catered to our design wishes. We now have a special drive tailored to our needs,” explains Holger Ludwig, Project Manager from ProMinent. ebm-papst in Lauf adapted the near-standard drive to the requirements of the patented hose-changing process of the pump. An extended drive shaft with a cross profile now fits as the perfect counterpart on the special axle shape of the rotor. This means the force of the motor is not only reliably transferred onto the hose, but also means that only half of the rotor needs to be removed during the change. “We have found a partner in ebm-papst that supports the precision of our products in the best possible way,” says Ludwig – and so the seeds are sown for further projects. 

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