Magnetic coupling at elevated temperatures

Magnetic couplings are used in many functions within pump, chemical, pharmaceutical, course of and safety industries. They are usually used with the aim of decreasing put on, sealing of liquids from the setting, cleanliness needs or as a safety issue to brake over if torque all of a sudden rises.
The commonest magnetic couplings are made with an outer and inside drive, each construct up with Neodymium magnets to find a way to get the highest torque density as possible. By optimizing the diameter, air gap, magnet dimension, number of poles and choice of magnet grade, it’s attainable to design a magnetic coupling that suits any utility in the range from few millinewton meter up to several hundred newton meters.
When solely optimizing for prime torque, the designers usually tend to forget contemplating the influence of temperature. If the designer refers back to the Curie point of the person magnets, he’ll declare that a Neodymium magnet would fulfill the necessities as much as more than 300°C. Concurrently, you will need to embody the temperature dependencies on the remanence, which is seen as a reversible loss – typically round 0,11% per diploma Celsius the temperature rises.
Furthermore, a neodymium magnet is underneath strain throughout operation of the magnetic coupling. This means that irreversible demagnetization will occur lengthy before the Curie level has been reached, which usually limits the usage of Neodymium-based magnetic coupling to temperatures below 150°C.
If greater temperatures are required, magnetic couplings made from Samarium Cobalt magnets (SmCo) are usually used. SmCo isn’t as sturdy as Neodymium magnets but can work as a lot as 350°C. Furthermore, the temperature coefficient of SmCo is just zero,04% per diploma Celsius which implies that it may be used in purposes the place efficiency stability is needed 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 assist from the Danish Innovation Foundation.
The purpose of the project was to develop a magnetic coupling that could broaden the working temperature area 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 subject of the outer drive with particular magnetic designs; it was possible to develop a magnetic coupling that started at a lower torque degree at room temperature, however only had a minor reduction in torque level as a function 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 can 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 inside drive and still performed with an virtually linear discount in torque.
The graph additionally reveals that the temperature coefficient of the High Hot coupling is even lower than for the SmCo-system, which opens a decrease temperature market the place efficiency stability is important over a bigger temperature interval.
Conclusion At Sintex, the R&D department is still developing on the expertise, however they must be challenged on torque degree at either completely different temperature, dimensions of the magnetic coupling or new applications that have not beforehand been possible with normal magnetic couplings, so as to harvest the complete potential of the High Hot expertise.
The High Hot coupling just isn’t seen as a standardized shelf product, however instead as custom-built by which is optimized for particular applications. Therefore, เกจวัดถังแก๊ส might be made in close collaboration with new partners.

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