Magnetic coupling at elevated temperatures

Magnetic couplings are used in many functions 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 wants or as a security factor to brake over if torque abruptly rises.
The most typical magnetic couplings are made with an outer and inner drive, both construct up with Neodymium magnets to have the ability to get the best torque density as possible. By optimizing the diameter, air gap, magnet dimension, variety of poles and selection of magnet grade, it is attainable to design a magnetic coupling that suits any utility in the vary from few millinewton meter as a lot as several hundred newton meters.
When solely optimizing for high torque, the designers usually are inclined to forget contemplating the influence of temperature. If the designer refers back to the Curie point of the person magnets, he will claim that a Neodymium magnet would fulfill the requirements as a lot as more than 300°C. Concurrently, เกจวัดแรงดันน้ำ is necessary to embody the temperature dependencies on the remanence, which is seen as a reversible loss – typically around 0,11% per degree Celsius the temperature rises.
Furthermore, a neodymium magnet is beneath pressure throughout operation of the magnetic coupling. This signifies that irreversible demagnetization will occur lengthy earlier than the Curie level has been reached, which usually limits the use of Neodymium-based magnetic coupling to temperatures under 150°C.
If larger temperatures are required, magnetic couplings manufactured from Samarium Cobalt magnets (SmCo) are sometimes used. SmCo is not as strong 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 means that it can be utilized in functions the place performance stability is needed over a larger temperature interval.
New era 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 support from the Danish Innovation Foundation.
The purpose of the venture was to develop a magnetic coupling that might increase the working temperature area to reach temperatures of molten salts round 600°C. By exchanging the internal drive with a magnetic material containing the next Curie level and boosting the magnetic area of the outer drive with particular magnetic designs; it was potential to develop a magnetic coupling that began at a decrease torque degree at room temperature, but only had a minor reduction in torque degree as a function of temperature. This resulted in superior performance above 160°C, irrespective of if the benchmark was towards a Neodymium- or Samarium Cobalt-based system. This may be seen in Figure 1, the place it’s proven that the torque stage of the High Hot drives has been examined up to 590°C on the inside drive and still carried out with an almost 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 the place performance stability is important over a bigger temperature interval.
Conclusion At Sintex, the R&D division is still growing on the technology, however they have to be challenged on torque stage at either totally different temperature, dimensions of the magnetic coupling or new purposes that have not previously been potential with standard magnetic couplings, so as to harvest the total potential of the High Hot know-how.
The High Hot coupling is not seen as a standardized shelf product, however instead as custom-built by which is optimized for particular applications. Therefore, additional improvement will be made in shut collaboration with new companions.

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