Magnetic Pumps are preferred choice for Critical Applications
Interview with Mr. Alexander Hammer, Managing Director, Dickow Pumpen GmbH & Co. KG, Waldkraiburg, Germany, Bachelor Professional of Technical Management (CCI), is innovator in technical management and expert in strategic business development in chemical, petrochemical, heat transfer, renewable energy & environmental technology sectors. He replied to Questionnaire from Pumps India about Magnetic drive pumps.
Q: In which industries are magnetic drive pumps most widely used, and why are they preferred there?
Magnetic pumps are used in almost every branch of industry. They are always the referred choice when absolute reliability is required – specially for hazardous, mutagenic, or explosive substances that pose a risk to people and the environment. They are also the preferred choice when low overall costs are a priority, as their low-maintenance, leak-free design reduces costs in the long term while ensuring maximum safety.
Dickow Pumps is represented in a wide range of industries worldwide. Typical sectors where Dickow pumps are used include:
-> Chemical and Petrochemical: For the safe transfer of aggressive, hazardous, or high-purity chemicals and products. Magnetic Pumps are preferred choice for Critical Applications
-> Oil & Gas: In the transport, storage, and refining of crude oil and natural gas, as well as in refineries.
-> Offshore, Ship Technology & Marine: For example, on drilling platforms or ships, where high reliability and standards are required.
-> Tank Farms & Refueling Facilities: For the transfer and distribution of fuels and chemicals.
-> Renewable Energy & Environmental Technology: Such as in the production of biosynthetic fuels, in solar and geothermal plants, and in recycling processes.
-> Industrial Heating and Heat Transfer Systems: For pumping thermal oils and other heat transfer media, often at high temperatures.
-> Water Supply and Treatment: Including applications such as seawater desalination.
-> Pharmaceutical and Food Industry: Wherever leak-free operation, hygiene, and operational safety are of utmost importance.
In addition, Dickow pumps are also used in many other industrial sectors such as aerospace, power generation, pulp and paper production, automotive, and various areas of general plant and mechanical engineering.Q: How does magnetic coupling eliminate the need for a mechanical seal ?
The basic principle of power transmission in magnetic couplings is the contactless transfer of torque via magnetic fields. Special magnets, usually permanent magnets, are mounted on two separate shafts (drive side and driven side). Their magnetic fields interact and move in sync – without any direct mechanical connection. When the drive shaft (for example, from a motor) rotates, the magnets on it create a magnetic field that also rotates the magnets on the driven shaft. The force – usually the torque – is transmitted solely through the magnetic field, not through physical contact. Thanks to an intermediate wall (containment shell which is the sealing element), the system remains completely sealed to the outside, and no media can escape. Since there is no continuous shaft passage to the atmosphere, the use of mechanical seals can be completely dispensed with. This means the transmission is wear-free, quiet, and leak-proof, making magnetic couplings particularly suitable for applications involving hazardous or valuable liquids.
Q: How are energy-efficient designs reducing the operational costs of magnetic drive pumps?
Advances in pump and impeller geometry, as well as the use of computer-aided design, enable better fluid dynamics within the pump. This optimization further increases the efficiency of how energy from the motor is transferred to the liquid, ensuring pump systems use only the energy required for actual process needs, not more.
Q : What are the typical energy losses in magnetic drive pumps, and how can they be minimized?
Energy efficient magnetic drive pump designs cut operating costs primarily through the use of variable frequency drives (VFDs), soft starts, and lossless containment shells. VFDs precisely match pump speed to actual process demand, eliminating idle losses and enabling smooth acceleration. This avoids oversizing the magnetic coupling for start up torque, further saving energy. Soft starts reduce in rush currents and mechanical stress,
allowing pump and coupling to be perfectly matched to real operating conditions. In addition, loss free, non metallic containment shells prevent the
eddy current losses typical of metallic versions, where electrical energy is wasted as heat. The result is significantly lower energy consumption, reduced wear, and minimized total costs-while maintaining the highest level of operational safety.
Q : What role does computational fluid dynamics (CFD) play in the design optimization of magnetic drive pumps?
CFD is used in magnetic drive pumps to precisely simulate the flow of liquid inside the pump. This makes it possible to detect flow losses, pressure patterns, and potential cavitation early on. Engineers can then optimize impeller shapes, channel geometry, and angles on the computer before building a prototype. The result is time and cost savings, higher efficiency, lower energy use, and a longer pump service life.
Q : What design modifications make magnetic drive pumps suitable for cryogenic or high-temperature applications?
The key difference making magnetic drive pumps suitable for cryogenic or high-temperature applications lies above all in the choice of materials: For
different temperature ranges, different metals, elastomers, and magnets are used. All wetted and pressure-bearing parts must be made from metals that can handle either extreme cold or heat without becoming brittle or losing strength. The selection of elastomers (seals, O-rings, gaskets) also depends
on temperature resistance: for cryogenic service, special low-temperature elastomers are needed, while for high temperature, only materials that won’t
degrade or lose elasticity are chosen. Finally, for the magnetic coupling, the pump uses magnet types specially tailored to the required temperature
range-since standard magnets can lose their strength at high temperatures or become brittle at extremely low temperatures. These targeted design
modifications ensure safe and reliable operation of magnetic drive pumps, even in the most demanding thermal conditions.
Q: What are the limitations of magnetic drive pumps when used with high-viscosity liquids? How are these pumps applied in pharmaceutical and semiconductor industries where contamination must be avoided?
Magnetic drive pumps are only partly suitable for high viscosity fluids, as the increased power demand reduces efficiency and can exceed the coupling’s
maximum torque, causing decoupling and overheating. Their strength lies in contamination sensitive environments: in the pharmaceutical industry, they
offer a leak free, low maintenance design with hygienic, compatible materials, allowing CIP/SIP cleaning and protection against product contamination; in semiconductor manufacturing, they transfer ultrapure media or aggressive chemicals without releasing particles or metal ions, ensuring maximum purity and process reliability.
Q : What advancements have been made in magnetic coupling technology to increase torque transmission?
The break through regarding reliability and saving initial costs came in the early 80’s with the availability of Cobalt- Samarium (SmCo) magnets and Silicon
Carbide (SiC) sleeve bearings. Before SmCo magnets, the standard choices were aluminum-nickel-cobalt (AlNiCo) and ferrit magnets, which could not provide the combination of high magnetic strength, temperature stability, and resistance to demagnetization necessary for tough industrial applications.
These advances, enabled magnetic couplings to move from a niche technology to widespread industrial adoption, particularly for applications where leak-free, maintenance-free, and high-temperature operation is essential.
Q: How are IoT and smart sensors being integrated into magnetic drive pumps for predictive maintenance?
The mag safe system from Dickow is an innovative monitoring solution for magnetic drive pumps with metallic containment shells. It continuously measures the temperature in the containment shell area using integrated sensors and thus detects early any operating issues such as dry running, blocked lubrication channels, bearing damage, or decoupled magnets. If the adjustable temperature limit is exceeded, the system triggers an alarm or automatically shuts down the pump before costly damage can occur. Key benefits: mag safe enables early damage detection, reliably preventing consequential damage to the pump and magnetic coupling. It provides maximum safety for personnel, environment, and equipment, and is approved for use in hazardous (Ex) areas. With predictive maintenance capabilities based on continuous digital monitoring, downtime and repair costs are minimized. The system reacts instantly to abnormal temperature rises, avoids unplanned shutdowns, extends pump life, and offers full process and maintenance transparency through digital logging of all measured values and service actions. It can be easily retrofitted to existing Dickow pumps and integrated into IoT or control systems, and the contactless sensors are virtually maintenance free. In short: mag safe delivers maximum operational safety, early problem detection, and optimized maintenance –ensuring highest pump availability atthe lowest life cycle cost.
Q: What safety features prevent decoupling of the magnets under overload conditions?
Modern magnetic couplings have sufficient safety reserves to prevent decoupling even under short-term overload. Additional protection comes from Dickow’s Mag Safe system, which monitors temperatures near the coupling and triggers alarms or shutdowns before damage occurs. Load monitors can also detect abnormal power changes and stop the pump, providing extra security against decoupling. In addition Soft starters and VFDs not only improve energy efficiency and flexibility, but also prevent decoupling during start up, especially with high power drives or Direct On Line (DOL) motor starts. By ramping up speed smoothly, they limit start up torque, avoid load peaks, protect pump and coupling from damage, and often eliminate the need for over dimensioning.
Q : What sets apart the Dickow Mag Drive pump from competition?
There is a unique Dickow internal circulation system in our magnetic drive pumps for heat management, operational safety and reliability, possible by circulation from discharge to discharge, using a rear impeller and a thrust load balancing system. These technical features sets the Dickow mag drive pump apart in demanding industrial applications & translates into following benefits for clients.
-> Client Benefits
Maximum process safety – Even with hot, volatile or toxic liquids thanks to advanced heat management and internal pressure control. Maintenance-friendly operation – Self- venting design and effective drainage simplify servicing and reduce downtime. Long-term cost efficiency – Reduced mechanical wear and minimized risk of vapor lock or cavitation translate to fewer repairs, longer MTBF & increased pump lifespan. Suitable for challenging fluids – Ideal for boiling, corrosive or hazardous media with demanding thermal and / or NPSH characteristics. Lowest Cost of Ownership and lowest Life cycle costs.
Dickow Pumpen GmbH & Co.
Alexander Hammer