Magnetic coupling at elevated temperatures

Magnetic couplings are utilized in many applications inside pump, chemical, pharmaceutical, course of and safety industries. They are sometimes used with the aim of lowering put on, sealing of liquids from the environment, cleanliness needs or as a security issue to brake over if torque abruptly rises.
เกจวัดแรงดันเชื้อเพลิง are made with an outer and inner drive, each build up with Neodymium magnets in order to get the best torque density as possible. 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 suits any application within the vary from few millinewton meter as a lot as several hundred newton meters.
When solely optimizing for prime torque, the designers typically are likely to forget considering the influence of temperature. If the designer refers again to the Curie point of the person magnets, he’ll declare that a Neodymium magnet would fulfill the requirements up to greater than 300°C. Concurrently, it could be very important embody the temperature dependencies on the remanence, which is seen as a reversible loss – sometimes round 0,11% per diploma Celsius the temperature rises.
Furthermore, a neodymium magnet is underneath strain during operation of the magnetic coupling. This signifies that irreversible demagnetization will happen lengthy earlier than the Curie level has been reached, which usually limits using Neodymium-based magnetic coupling to temperatures under 150°C.
If larger temperatures are required, magnetic couplings made from Samarium Cobalt magnets (SmCo) are usually used. SmCo isn’t as sturdy as Neodymium magnets however can work as a lot as 350°C. Furthermore, the temperature coefficient of SmCo is only 0,04% per degree Celsius which implies that it can be used in applications 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 model new technology of magnetic couplings has been developed by Sintex with help from the Danish Innovation Foundation.
The objective of the project was to develop a magnetic coupling that might increase the working temperature space to succeed in temperatures of molten salts around 600°C. By exchanging the internal drive with a magnetic materials containing the next Curie point and boosting the magnetic field of the outer drive with particular magnetic designs; it was attainable to develop a magnetic coupling that started at a decrease torque degree at room temperature, but only had a minor discount in torque degree as a perform of temperature. This resulted in superior efficiency above 160°C, no matter if the benchmark was in opposition to a Neodymium- or Samarium Cobalt-based system. This can be seen in Figure 1, the place it’s proven that the torque degree of the High Hot drives has been tested up to 590°C on the internal drive and nonetheless carried out with an nearly linear reduction in torque.
The graph also exhibits 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 essential over a larger temperature interval.
Conclusion At Sintex, the R&D division continues to be growing on the know-how, but they need to be challenged on torque degree at either totally different temperature, dimensions of the magnetic coupling or new applications that haven’t beforehand been potential with commonplace magnetic couplings, so as to harvest the full potential of the High Hot expertise.
The High Hot coupling isn’t seen as a standardized shelf product, however as a substitute as custom-built by which is optimized for specific applications. Therefore, additional development shall be made in close collaboration with new companions.

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