Magnetic couplings are utilized in many purposes inside pump, chemical, pharmaceutical, process and safety industries. They are usually used with the purpose of lowering wear, sealing of liquids from the setting, cleanliness wants or as a safety factor to brake over if torque all of a sudden rises.
The most common magnetic couplings are made with an outer and internal drive, both construct up with Neodymium magnets so as to get the highest torque density as potential. By optimizing the diameter, air hole, magnet measurement, number of poles and choice of magnet grade, it’s potential to design a magnetic coupling that suits any utility in the vary from few millinewton meter as much as a quantity of hundred newton meters.
When solely optimizing for top torque, the designers often are likely to overlook contemplating the affect of temperature. If the designer refers to the Curie level of the person magnets, he’ll declare that a Neodymium magnet would fulfill the requirements as a lot as greater than 300°C. Concurrently, it may be very important include 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 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 usage of Neodymium-based magnetic coupling to temperatures beneath 150°C.
If larger temperatures are required, magnetic couplings manufactured from Samarium Cobalt magnets (SmCo) are typically used. SmCo isn’t เครื่องมือตรวจวัดความดันเลือดเรียกว่า as Neodymium magnets but can work as a lot as 350°C. Furthermore, the temperature coefficient of SmCo is only 0,04% per diploma Celsius which means that it may be utilized in purposes where efficiency stability is needed over a larger temperature interval.
New generation In collaboration with Copenhagen Atomics, Alfa Laval, Aalborg CSP and the Technical University of Denmark a model new era of magnetic couplings has been developed by Sintex with help from the Danish Innovation Foundation.
The function of the venture was to develop a magnetic coupling that would broaden the working temperature area to achieve temperatures of molten salts around 600°C. By exchanging the internal drive with a magnetic material containing the next Curie point and boosting the magnetic area of the outer drive with particular magnetic designs; it was possible to develop a magnetic coupling that started at a decrease torque level at room temperature, but solely had a minor discount in torque degree as a operate of temperature. This resulted in superior efficiency above 160°C, regardless of if the benchmark was towards a Neodymium- or Samarium Cobalt-based system. This could be seen in Figure 1, where it is shown that the torque level of the High Hot drives has been tested up to 590°C on the inside drive and still carried out with an almost linear discount in torque.
The graph also 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 performance stability is necessary over a bigger temperature interval.
Conclusion At Sintex, the R&D division remains to be growing on the know-how, but they need to be challenged on torque level at both completely different temperature, dimensions of the magnetic coupling or new functions that have not beforehand been attainable with commonplace magnetic couplings, to be able to harvest the full potential of the High Hot know-how.
The High Hot coupling is not seen as a standardized shelf product, but as a substitute as custom-built by which is optimized for specific functions. Therefore, further development might be made in shut collaboration with new companions.
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