Magnetic coupling at elevated temperatures

Magnetic couplings are utilized in many applications inside pump, chemical, pharmaceutical, course of and security industries. They are usually used with the purpose of decreasing put on, sealing of liquids from the surroundings, cleanliness needs or as a security issue to brake over if torque suddenly rises.
The most common magnetic couplings are made with an outer and inside drive, both build up with Neodymium magnets in order to get the best torque density as potential. By optimizing the diameter, air hole, magnet dimension, variety of poles and selection of magnet grade, it’s attainable to design a magnetic coupling that fits any utility in the range from few millinewton meter as a lot as a number of hundred newton meters.
When solely optimizing for prime torque, the designers usually tend to neglect contemplating the influence of temperature. If the designer refers again to the Curie point of the individual magnets, he’ll claim that a Neodymium magnet would fulfill the necessities up to more than 300°C. Concurrently, you will want to include the temperature dependencies on the remanence, which is seen as a reversible loss – usually round 0,11% per diploma Celsius the temperature rises.
Furthermore, a neodymium magnet is beneath strain throughout operation of the magnetic coupling. This implies that irreversible demagnetization will happen lengthy before the Curie point has been reached, which usually limits the use of Neodymium-based magnetic coupling to temperatures below 150°C.
If higher temperatures are required, magnetic couplings made from Samarium Cobalt magnets (SmCo) are sometimes used. compound gauge ราคา isn’t as robust as Neodymium magnets however can work up to 350°C. Furthermore, the temperature coefficient of SmCo is just zero,04% per degree Celsius which signifies that it can be used in functions where efficiency stability is required over a bigger 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 project was to develop a magnetic coupling that could increase the working temperature area to achieve temperatures of molten salts around 600°C. By exchanging the inner drive with a magnetic materials containing the next Curie point and boosting the magnetic area of the outer drive with particular magnetic designs; it was potential to develop a magnetic coupling that began at a lower torque stage at room temperature, however solely had a minor discount in torque level as a perform of temperature. This resulted in superior efficiency above 160°C, regardless of if the benchmark was against a Neodymium- or Samarium Cobalt-based system. This may be seen in Figure 1, the place it’s shown that the torque level of the High Hot drives has been examined up to 590°C on the inner drive and nonetheless carried out with an nearly linear reduction in torque.
The graph additionally exhibits that the temperature coefficient of the High Hot coupling is even lower than for the SmCo-system, which opens a lower temperature market the place efficiency stability is necessary over a larger temperature interval.
Conclusion At Sintex, the R&D department remains to be growing on the know-how, however they need to be challenged on torque degree at both totally different temperature, dimensions of the magnetic coupling or new functions that haven’t beforehand been possible with normal magnetic couplings, to be able to harvest the total potential of the High Hot know-how.
The High Hot coupling just isn’t seen as a standardized shelf product, however instead as custom-built by which is optimized for specific functions. Therefore, additional growth shall be made in shut collaboration with new partners.

Leave a Comment