Magnetic couplings are used in many applications within pump, chemical, pharmaceutical, process and safety industries. เครื่องมือความดัน are typically used with the aim of lowering wear, sealing of liquids from the surroundings, cleanliness wants or as a security factor to brake over if torque suddenly rises.
The most common magnetic couplings are made with an outer and inside drive, both build up with Neodymium magnets to have the ability to get the very best torque density as possible. By optimizing the diameter, air hole, magnet measurement, number of poles and selection of magnet grade, it is potential to design a magnetic coupling that fits any utility within the vary from few millinewton meter as a lot as several hundred newton meters.
When only optimizing for top torque, the designers usually tend to overlook considering the affect of temperature. If the designer refers to the Curie point of the individual magnets, he’ll declare that a Neodymium magnet would fulfill the necessities up to more than 300°C. Concurrently, you will want to embody the temperature dependencies on the remanence, which is seen as a reversible loss – sometimes around 0,11% per degree Celsius the temperature rises.
Furthermore, a neodymium magnet is underneath stress throughout operation of the magnetic coupling. This means that irreversible demagnetization will occur lengthy before the Curie level has been reached, which usually limits the utilization of Neodymium-based magnetic coupling to temperatures beneath 150°C.
If larger temperatures are required, magnetic couplings made from Samarium Cobalt magnets (SmCo) are usually used. SmCo is not as strong as Neodymium magnets but can work up to 350°C. Furthermore, the temperature coefficient of SmCo is just 0,04% per diploma Celsius which signifies that it might be utilized in applications where performance 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 new generation of magnetic couplings has been developed by Sintex with assist from the Danish Innovation Foundation.
The function of the project was to develop a magnetic coupling that might increase the working temperature area to achieve temperatures of molten salts around 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 particular magnetic designs; it was attainable to develop a magnetic coupling that started at a decrease torque stage at room temperature, but solely had a minor discount in torque stage as a operate of temperature. This resulted in superior efficiency above 160°C, irrespective of if the benchmark was against a Neodymium- or Samarium Cobalt-based system. This may be seen in Figure 1, the place it’s shown that the torque stage of the High Hot drives has been examined up to 590°C on the internal 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 decrease than for the SmCo-system, which opens a decrease temperature market the place performance stability is essential over a larger temperature interval.
Conclusion At Sintex, the R&D department remains to be creating on the expertise, however they have to be challenged on torque degree at either totally different temperature, dimensions of the magnetic coupling or new functions that have not beforehand been potential with normal magnetic couplings, so as to harvest the full potential of the High Hot know-how.
The High Hot coupling is not seen as a standardized shelf product, however as a substitute as custom-built by which is optimized for particular applications. Therefore, additional growth will be made in close collaboration with new companions.
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