Magnetic coupling at elevated temperatures

Magnetic couplings are used in many functions inside pump, chemical, pharmaceutical, course of and safety industries. They are sometimes used with the aim of decreasing 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 typical 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 gap, magnet measurement, number of poles and choice of magnet grade, it is attainable to design a magnetic coupling that fits any utility within the range from few millinewton meter up to a quantity of hundred newton meters.
When solely optimizing for prime torque, the designers often are most likely to overlook contemplating the affect of temperature. If the designer refers back to the Curie point of the individual magnets, he will declare that a Neodymium magnet would fulfill the necessities as much as greater than 300°C. Concurrently, you will need to include the temperature dependencies on the remanence, which is seen as a reversible loss – typically around zero,11% per degree Celsius the temperature rises.
Furthermore, a neodymium magnet is under strain throughout operation of the magnetic coupling. This means that irreversible demagnetization will happen lengthy before the Curie level has been reached, which usually limits the use of Neodymium-based magnetic coupling to temperatures beneath 150°C.
If higher temperatures are required, magnetic couplings made from Samarium Cobalt magnets (SmCo) are usually used. SmCo just isn’t as sturdy as Neodymium magnets but can work as much as 350°C. Furthermore, the temperature coefficient of SmCo is only zero,04% per degree Celsius which signifies that it can be used in applications the place 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 generation of magnetic couplings has been developed by Sintex with help from the Danish Innovation Foundation.
The purpose of the project was to develop a magnetic coupling that could increase the working temperature area to reach temperatures of molten salts round 600°C. By exchanging the inner 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 attainable to develop a magnetic coupling that began at a lower torque degree at room temperature, but only had a minor discount in torque degree as a perform of temperature. This resulted in superior performance above 160°C, regardless of if the benchmark was against a Neodymium- or Samarium Cobalt-based system. pressure gauge trerice ราคา can be seen in Figure 1, the place it is shown that the torque level of the High Hot drives has been tested as much as 590°C on the internal drive and nonetheless performed with an nearly linear discount 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 performance stability is essential over a bigger temperature interval.
Conclusion At Sintex, the R&D division remains to be developing on the technology, however they need to be challenged on torque stage at either totally different temperature, dimensions of the magnetic coupling or new applications that have not beforehand been potential with commonplace magnetic couplings, in order to harvest the full potential of the High Hot technology.
The High Hot coupling is not seen as a standardized shelf product, however instead as custom-built by which is optimized for particular functions. Therefore, additional development shall be made in close collaboration with new companions.
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