Magnetic coupling at elevated temperatures

Magnetic couplings are utilized in many applications inside pump, chemical, pharmaceutical, process and security industries. They are usually used with the aim of decreasing put on, sealing of liquids from the setting, cleanliness wants or as a safety factor to brake over if torque abruptly rises.
The most typical magnetic couplings are made with an outer and inside drive, each construct up with Neodymium magnets so as to get the very best torque density as possible. By optimizing the diameter, air hole, magnet size, number of poles and choice of magnet grade, it is potential to design a magnetic coupling that suits any software in the vary from few millinewton meter as much as several hundred newton meters.
When solely optimizing for prime torque, the designers typically are most likely to overlook considering the influence of temperature. If the designer refers to the Curie point of the person magnets, he will claim that a Neodymium magnet would fulfill the requirements up to more than 300°C. Concurrently, it may be very important include the temperature dependencies on the remanence, which is seen as a reversible loss – usually around 0,11% per diploma Celsius the temperature rises.
Furthermore, a neodymium magnet is under stress during operation of the magnetic coupling. This signifies that irreversible demagnetization will occur long before the Curie level has been reached, which usually limits using Neodymium-based magnetic coupling to temperatures below 150°C.
If pressure gauge digital ราคา are required, magnetic couplings made of Samarium Cobalt magnets (SmCo) are sometimes used. SmCo isn’t as robust as Neodymium magnets however can work as a lot as 350°C. Furthermore, the temperature coefficient of SmCo is simply 0,04% per diploma Celsius which implies that it might be utilized in applications where efficiency 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 generation of magnetic couplings has been developed by Sintex with support from the Danish Innovation Foundation.
The purpose of the venture was to develop a magnetic coupling that might expand the working temperature area to reach temperatures of molten salts round 600°C. By exchanging the internal drive with a magnetic material containing a better Curie level and boosting the magnetic area of the outer drive with special magnetic designs; it was attainable to develop a magnetic coupling that began at a lower torque degree at room temperature, however only had a minor discount in torque level as a operate 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, where it’s proven that the torque degree of the High Hot drives has been tested up to 590°C on the inner drive and nonetheless carried out with an virtually 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 decrease temperature market where performance stability is important over a larger temperature interval.
Conclusion At Sintex, the R&D division remains to be developing on the technology, however they need to be challenged on torque degree at either completely different temperature, dimensions of the magnetic coupling or new functions that have not beforehand been potential with normal magnetic couplings, so as 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 as a substitute as custom-built by which is optimized for specific functions. Therefore, further improvement will be made in shut collaboration with new companions.

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