Magnetic coupling at elevated temperatures

Magnetic couplings are used in many applications within pump, chemical, pharmaceutical, process and security industries. They are sometimes used with the aim of decreasing wear, sealing of liquids from the setting, cleanliness wants or as a security factor to brake over if torque all of a sudden rises.
The most typical magnetic couplings are made with an outer and inner drive, both build up with Neodymium magnets to be able to get the highest torque density as attainable. By optimizing the diameter, air hole, magnet dimension, variety of poles and choice of magnet grade, it is potential to design a magnetic coupling that suits any application in the vary from few millinewton meter up to several hundred newton meters.
When only optimizing for prime torque, the designers usually tend to overlook contemplating the affect of temperature. If the designer refers back to the Curie level of the individual magnets, he will claim that a Neodymium magnet would fulfill the necessities as a lot as more than 300°C. Concurrently, it could be very important include the temperature dependencies on the remanence, which is seen as a reversible loss – usually around zero,11% per degree Celsius the temperature rises.
Furthermore, a neodymium magnet is beneath strain during operation of the magnetic coupling. This means that irreversible demagnetization will happen lengthy before the Curie point has been reached, which typically limits the utilization of Neodymium-based magnetic coupling to temperatures beneath 150°C.
If higher temperatures are required, magnetic couplings manufactured from Samarium Cobalt magnets (SmCo) are sometimes used. SmCo just isn’t as sturdy as Neodymium magnets but can work up to 350°C. Furthermore, the temperature coefficient of SmCo is simply zero,04% per diploma Celsius which implies that it can be used in functions the place efficiency stability is required over a larger temperature interval.
New technology In collaboration with Copenhagen Atomics, Alfa Laval, Aalborg CSP and the Technical University of Denmark a new era of magnetic couplings has been developed by Sintex with help from the Danish Innovation Foundation.
เครื่องมือที่ใช้วัดความดัน of the challenge was to develop a magnetic coupling that could increase the working temperature space to succeed in temperatures of molten salts round 600°C. By exchanging the inside drive with a magnetic materials containing the next Curie point and boosting the magnetic subject of the outer drive with particular magnetic designs; it was attainable to develop a magnetic coupling that started at a lower torque stage at room temperature, but solely had a minor reduction in torque level as a operate of temperature. This resulted in superior efficiency above 160°C, no matter if the benchmark was towards a Neodymium- or Samarium Cobalt-based system. This may be seen in Figure 1, the place it’s proven that the torque stage of the High Hot drives has been tested as much as 590°C on the inside drive and still performed with an nearly linear reduction in torque.
The graph additionally shows that the temperature coefficient of the High Hot coupling is even decrease than for the SmCo-system, which opens a decrease temperature market where performance stability is important over a larger temperature interval.
Conclusion At Sintex, the R&D department remains to be developing on the know-how, but they need to be challenged on torque stage at either completely different temperature, dimensions of the magnetic coupling or new functions that haven’t beforehand been potential with commonplace magnetic couplings, in order to harvest the total potential of the High Hot technology.
The High Hot coupling isn’t seen as a standardized shelf product, however instead as custom-built by which is optimized for specific functions. Therefore, further development will be made in close collaboration with new partners.

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