Magnetic coupling at elevated temperatures

Magnetic couplings are used in many applications within pump, chemical, pharmaceutical, process and security industries. They are usually used with the purpose of reducing wear, sealing of liquids from the setting, cleanliness needs or as a security issue to brake over if torque suddenly rises.
The most typical magnetic couplings are made with an outer and inside drive, both construct up with Neodymium magnets in order to get the very best torque density as possible. By optimizing the diameter, air gap, magnet size, number of poles and choice of magnet grade, it’s attainable to design a magnetic coupling that fits any software in the range from few millinewton meter up to several hundred newton meters.
When only optimizing for prime torque, the designers usually tend to neglect contemplating the affect of temperature. If the designer refers to the Curie level of the person magnets, he will claim that a Neodymium magnet would fulfill the requirements up to greater than 300°C. Concurrently, you will need to include the temperature dependencies on the remanence, which is seen as a reversible loss – typically round 0,11% per degree Celsius the temperature rises.
Furthermore, a neodymium magnet is underneath strain throughout operation of the magnetic coupling. This signifies that irreversible demagnetization will occur lengthy earlier than the Curie point has been reached, which typically limits the use of Neodymium-based magnetic coupling to temperatures under 150°C.
If higher temperatures are required, magnetic couplings manufactured from Samarium Cobalt magnets (SmCo) are sometimes used. SmCo is not as robust as Neodymium magnets however can work up to 350°C. Furthermore, the temperature coefficient of SmCo is just 0,04% per diploma Celsius which implies that it can be used in purposes the place efficiency stability is needed over a larger temperature interval.
New era In collaboration with Copenhagen Atomics, Alfa Laval, Aalborg CSP and the Technical University of Denmark a model new generation of magnetic couplings has been developed by Sintex with assist from the Danish Innovation Foundation.
The function of the challenge was to develop a magnetic coupling that would expand the working temperature area to succeed in temperatures of molten salts around 600°C. By exchanging the inside drive with a magnetic material containing a higher Curie point and boosting the magnetic subject of the outer drive with particular magnetic designs; it was potential to develop a magnetic coupling that began at a lower torque level at room temperature, but only had a minor reduction in torque level as a operate of temperature. เกจวัดแรงดันน้ำไทวัสดุ resulted in superior performance above 160°C, no matter if the benchmark was against a Neodymium- or Samarium Cobalt-based system. This may be seen in Figure 1, where it’s proven that the torque stage of the High Hot drives has been tested as much as 590°C on the internal drive and still performed with an nearly linear reduction in torque.
The graph additionally reveals that the temperature coefficient of the High Hot coupling is even decrease than for the SmCo-system, which opens a lower temperature market where efficiency stability is necessary over a bigger temperature interval.
Conclusion At Sintex, the R&D department continues to be developing on the expertise, however they have to be challenged on torque level at either completely different temperature, dimensions of the magnetic coupling or new purposes that have not beforehand been possible with normal magnetic couplings, to be able to harvest the full potential of the High Hot technology.
The High Hot coupling just isn’t seen as a standardized shelf product, but as a substitute as custom-built by which is optimized for specific functions. Therefore, further growth shall be made in close collaboration with new partners.

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