Magnetic coupling at elevated temperatures

Magnetic couplings are used in many applications inside pump, chemical, pharmaceutical, course of and safety industries. They are usually used with the aim of reducing wear, sealing of liquids from the surroundings, cleanliness needs 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 inner drive, each build up with Neodymium magnets in order to get the highest torque density as possible. By optimizing the diameter, air hole, magnet size, number of poles and selection of magnet grade, it is potential to design a magnetic coupling that suits any application in the vary from few millinewton meter as a lot as several hundred newton meters.
When only optimizing for top torque, the designers usually are inclined to neglect considering the affect of temperature. If the designer refers again to the Curie level of the individual magnets, he will claim that a Neodymium magnet would fulfill the necessities up to greater than 300°C. Concurrently, pressure gauge 0 10 bar ราคา may be very important embody the temperature dependencies on the remanence, which is seen as a reversible loss – sometimes around zero,11% per diploma Celsius the temperature rises.
Furthermore, a neodymium magnet is under pressure throughout operation of the magnetic coupling. This signifies that irreversible demagnetization will happen long before the Curie level has been reached, which generally limits the utilization of Neodymium-based magnetic coupling to temperatures under 150°C.
If higher temperatures are required, magnetic couplings made of Samarium Cobalt magnets (SmCo) are sometimes used. SmCo is not as sturdy as Neodymium magnets however can work up to 350°C. Furthermore, the temperature coefficient of SmCo is simply 0,04% per diploma Celsius which means that it can be used in functions where performance 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 new technology of magnetic couplings has been developed by Sintex with support from the Danish Innovation Foundation.
The function of the challenge was to develop a magnetic coupling that might increase the working temperature space to reach temperatures of molten salts round 600°C. By exchanging the inside drive with a magnetic material containing a higher Curie level and boosting the magnetic area of the outer drive with particular magnetic designs; it was possible to develop a magnetic coupling that started at a decrease torque stage at room temperature, but only had a minor reduction in torque stage as a function of temperature. This resulted in superior efficiency above 160°C, irrespective of 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 degree of the High Hot drives has been examined up to 590°C on the inner drive and nonetheless performed with an virtually linear reduction in torque.
The graph also reveals 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 essential over a larger temperature interval.
Conclusion At Sintex, the R&D department continues to be creating on the technology, however they need to be challenged on torque level at either totally different temperature, dimensions of the magnetic coupling or new functions that haven’t previously been potential with standard magnetic couplings, so as to harvest the complete potential of the High Hot technology.
The High Hot coupling isn’t seen as a standardized shelf product, but as a substitute as custom-built by which is optimized for particular purposes. Therefore, additional growth shall be made in shut collaboration with new partners.

Scroll to Top