Magnetic couplings are utilized in many functions within pump, chemical, pharmaceutical, process and safety industries. They are sometimes used with the aim of lowering put on, sealing of liquids from the setting, cleanliness wants or as a safety factor to brake over if torque suddenly rises.
The most common magnetic couplings are made with an outer and internal drive, both construct up with Neodymium magnets in order to get the very best torque density as potential. By optimizing the diameter, air hole, magnet size, number of poles and selection of magnet grade, it’s potential to design a magnetic coupling that fits any utility within the vary from few millinewton meter up to several hundred newton meters.
When solely optimizing for prime torque, the designers usually tend to overlook contemplating the influence of temperature. If the designer refers back to the Curie level of the person magnets, he’ll claim that a Neodymium magnet would fulfill the necessities as much as greater than 300°C. Concurrently, you will want to embrace the temperature dependencies on the remanence, which is seen as a reversible loss – sometimes round zero,11% per diploma Celsius the temperature rises.
Furthermore, a neodymium magnet is under pressure throughout operation of the magnetic coupling. This means that irreversible demagnetization will occur long earlier than the Curie point has been reached, which generally limits using Neodymium-based magnetic coupling to temperatures under 150°C.
If higher temperatures are required, magnetic couplings manufactured from Samarium Cobalt magnets (SmCo) are sometimes used. SmCo isn’t as robust as Neodymium magnets however can work up to 350°C. Furthermore, the temperature coefficient of SmCo is simply zero,04% per diploma Celsius which means that it can be utilized in applications where efficiency stability is required over a bigger temperature interval.
New technology 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 assist from the Danish Innovation Foundation.
The objective of the venture was to develop a magnetic coupling that would broaden the working temperature area to reach temperatures of molten salts round 600°C. By exchanging the inside drive with a magnetic material containing the next Curie level and boosting the magnetic subject of the outer drive with special magnetic designs; it was potential to develop a magnetic coupling that began at a lower torque degree at room temperature, however solely had a minor discount in torque stage as a operate 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 may be seen in Figure 1, where 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 virtually linear reduction in torque.
เกจวัดแรงดันpcp shows 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 department continues to be developing on the expertise, however they have to be challenged on torque level at both completely different temperature, dimensions of the magnetic coupling or new functions that haven’t beforehand been attainable 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, but as an alternative as custom-built by which is optimized for specific functions. Therefore, additional improvement might be made in shut collaboration with new partners.
Share