When it comes to pump selection, alongside technical issues and regulations relating to safety and environmental protection, for instance, the financial aspect is regarded as the most important factor. If we only considered the procurement costs, however, it would be like comparing apples with oranges. Special centrifugal pumps from Bungartz are used for unconventional solutions to complex pumping tasks, of which the chemical industry boasts an abundance. They are designed for those situations where conventional pumps fail, being developed and built on site exclusively for a particular application. Such situations typically include the replacement of an old pump, retrofits due to frequent failures within a process chain or initial installation in a new construction project.
Engineers love solving problems
“The more difficult the operating conditions, the more important it is to have excellent teamwork between everyone involved”, explains Sadko Meusel, Head of Sales at pump manufacturer Bungartz. Our common goal is to find the technically and economically optimal solution. Over the course of decades, the company has developed its own philosophy with which to achieve this, based on its special pump technology backed up by corresponding special methods. In contrast to manufacturers that sell standardised pumps, Bungartz relies on custom-built centrifugal pumps. Furthermore, competent and dedicated staff in the sales offices are available to advise clients in Germany and worldwide. They are solution-oriented and familiar with a wide range of requirements thanks to several decades of experience. Since they are committed to achieving the best possible solution, just like the manufacturer’s engineers and designers, they know that efficient communication between all stakeholders in the planning process is essential. Consultants, planners, plant and operations engineers and technicians in the customer’s relevant departments each contribute their respective expertise, as do the specialists at Bungartz’ production facility in Euskirchen.
This can get interesting where special challenges arise, such as sensitive media that must be pumped in explosive atmosphere, temporary pumping tasks or fluids with a tendency to crystallise or polymerise. However unusual the application, a technically and economically optimal solution is always developed. “There’s a real sense of achievement, working together with process and project engineers to develop our self-regulating pumps for use in different plants. Customers are always amazed that they don’t need any additional control system technology. If it’s also possible to economise on construction work that had previously been considered or planned, they’re delighted”, says Meusel.
“You can’t use something that you haven’t heard of”, says the current CEO, Frank Bungartz. He describes the principle as follows: “Our three-pillar model allows us to develop the most suitable pump for even the most difficult application.”
Pillar one: the sealing technology. Almost all pumps combine the hydrodynamic shaft seal as a primary seal with a downstream secondary seal capable of dry running. The permanent dry-running safety results in an extremely long service life. “In practice, what that means is this: in very aggressive applications, which are challenging for seals, the pumped medium is kept well away from the actual seal during operation and even in the idle state. Very often, the traditional (secondary) seal never even comes into contact with the medium and is therefore not subject to much wear. This alone leads to a far longer service life”, Bungartz adds.
Effective self-regulating behaviour
Pillar two: the special physics. This is what we call the effective self-regulating behaviour of the V-AN pump series. These pumps automatically adapt to changing feed rates. Their NPSH value is almost 0, meaning that they are cavitation-free, even if the vapour pressure is reached in the pump reservoir. This occurs without any mechanical or electrical regulation equipment, making these pumps intrinsically safe. The high level of intrinsic safety allows plant and maintenance costs to be kept continuously low.
Pillar three: the choice of material. The range of materials comprises all castable and weldable stainless steel grades, special alloys (titanium, zirconium), grey cast iron and even components made from SiC. “Selecting the correct material makes the pumps very robust. In some highly complex cases, changing the pump can increase the service life from just six weeks previously to more than six months”, says the CEO, describing the experience of the Bungartz team.
What’s more, the selection and use of these special pumps eliminate virtually all known causes of faults in advance, as one real-life example illustrates. At the Gendorf chemical plant, a process change required different chemical waste water flows (acidic, solids) to be pumped from production processes into another operational area. Josef Lehner, Head of the “Pumps” specialist unit, chose to go with Bungartz pumps (see cav 5/2015 “Ohne Netz und doppelte Pumpe” (Without a safety net or double pumps)). Lehner is a renowned expert on the Pump Engineering distance-learning course (www.pump-engineer.org). Bungartz was known to the pump specialist as a supplier, as were the advantages of the V-AN pumps, which get by without additional control systems. As an experienced practitioner, he also knows that two of the fundamental requirements when considering a manufacturer’s quotation are how reliable their statements about pump characteristics are and how smooth their teamwork is during commissioning.
“We are always looking for new methods to illustrate our technology”, says Sadko Meusel. When words are not enough, explanatory models are needed. At trade fairs, conventions and industry exhibitions, Bungartz has for some time been offering functional models to try out. “Our local Technology Days event uses our mobile demonstration stand and has proven very effective”, Meusel comments. The pumps can be operated either in normal suction mode or, as Bungartz calls it, in abnormal mode. This highlights the advantages of the special physics and makes the differences clearly visible.
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