Magnetic coupling at elevated temperatures

Magnetic couplings are utilized in many purposes inside pump, chemical, pharmaceutical, process and security industries. They are typically used with the aim of reducing put on, sealing of liquids from the environment, cleanliness wants or as a security issue to brake over if torque all of a sudden rises.
The most common magnetic couplings are made with an outer and inside drive, both build up with Neodymium magnets so as to get the very best torque density as potential. By optimizing the diameter, air hole, magnet measurement, variety of poles and choice of magnet grade, it is potential to design a magnetic coupling that fits any application within the vary from few millinewton meter up to several hundred newton meters.
When only optimizing for prime torque, the designers usually are inclined to forget contemplating the affect of temperature. If the designer refers to the Curie level of the individual magnets, he’ll declare that a Neodymium magnet would fulfill the requirements up to greater than 300°C. Concurrently, it is important to embody the temperature dependencies on the remanence, which is seen as a reversible loss – usually around zero,11% per diploma Celsius the temperature rises.
Furthermore, a neodymium magnet is beneath pressure during operation of the magnetic coupling. This signifies that irreversible demagnetization will happen lengthy earlier than the Curie point has been reached, which generally limits the utilization of Neodymium-based magnetic coupling to temperatures beneath 150°C.
If higher temperatures are required, magnetic couplings made from Samarium Cobalt magnets (SmCo) are typically used. SmCo isn’t as strong as Neodymium magnets however can work as a lot as 350°C. Furthermore, the temperature coefficient of SmCo is simply zero,04% per degree Celsius which signifies that it may be used in applications where performance stability is required over a bigger temperature interval.
New generation In collaboration with Copenhagen Atomics, Alfa Laval, Aalborg CSP and the Technical University of Denmark a brand new technology of magnetic couplings has been developed by Sintex with assist from the Danish Innovation Foundation.
The objective of the project was to develop a magnetic coupling that could expand the working temperature space to achieve temperatures of molten salts round 600°C. By exchanging the internal drive with a magnetic materials containing a better Curie point and boosting the magnetic subject of the outer drive with particular magnetic designs; it was possible to develop a magnetic coupling that began at a decrease torque degree at room temperature, but only had a minor reduction in torque level as a perform of temperature. This resulted in superior performance above 160°C, no matter if the benchmark was towards a Neodymium- or Samarium Cobalt-based system. This could be seen in Figure 1, the place it is shown that the torque level of the High Hot drives has been examined up to 590°C on the inner drive and still carried out with an virtually linear reduction in torque.
The graph also reveals that the temperature coefficient of the High Hot coupling is even lower than for the SmCo-system, which opens a lower temperature market where performance stability is necessary over a larger temperature interval.
Conclusion At Sintex, the R&D department remains to be growing on the technology, however they need to be challenged on torque degree at both different temperature, dimensions of the magnetic coupling or new purposes that have not previously been possible with standard magnetic couplings, in order to harvest the full potential of the High Hot technology.
เกจ์วัดแก๊สหุงต้ม isn’t seen as a standardized shelf product, but as a substitute as custom-built by which is optimized for specific purposes. Therefore, additional improvement might be made in shut collaboration with new partners.
Share

Leave a Comment