Magnetic coupling at elevated temperatures

Magnetic couplings are used in many applications inside pump, chemical, pharmaceutical, process and security industries. They are sometimes used with the aim of decreasing wear, sealing of liquids from the surroundings, cleanliness needs 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 inside drive, each construct up with Neodymium magnets to find a way to get the best torque density as attainable. By optimizing the diameter, air hole, magnet dimension, number of poles and choice of magnet grade, it is potential to design a magnetic coupling that fits any software within the range from few millinewton meter as a lot as a quantity of hundred newton meters.
When only optimizing for prime torque, the designers usually are likely to overlook contemplating the influence 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 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 around 0,11% per diploma Celsius the temperature rises.
Furthermore, a neodymium magnet is under strain during operation of the magnetic coupling. This signifies that irreversible demagnetization will occur lengthy earlier than the Curie point has been reached, which typically limits the use of Neodymium-based magnetic coupling to temperatures below 150°C.
If greater temperatures are required, magnetic couplings manufactured from Samarium Cobalt magnets (SmCo) are usually used. pressure gauge 4 นิ้ว ราคา is not as strong as Neodymium magnets but can work as a lot as 350°C. Furthermore, the temperature coefficient of SmCo is just 0,04% per degree Celsius which implies that it may be used in functions the place performance stability is required over a larger 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 challenge was to develop a magnetic coupling that would increase the working temperature space to achieve temperatures of molten salts around 600°C. By exchanging the inside drive with a magnetic material containing a higher Curie point and boosting the magnetic field of the outer drive with special magnetic designs; it was attainable to develop a magnetic coupling that started at a lower torque stage at room temperature, but only had a minor reduction in torque level as a function of temperature. This resulted in superior efficiency above 160°C, no matter if the benchmark was in opposition to a Neodymium- or Samarium Cobalt-based system. This can be seen in Figure 1, the place it’s proven that the torque stage of the High Hot drives has been examined as much as 590°C on the inside drive and nonetheless performed with an nearly linear discount in torque.
The graph additionally exhibits that the temperature coefficient of the High Hot coupling is even decrease than for the SmCo-system, which opens a lower temperature market where efficiency stability is necessary over a bigger temperature interval.
Conclusion At Sintex, the R&D division remains to be developing on the technology, but they have to be challenged on torque degree at both different temperature, dimensions of the magnetic coupling or new functions that haven’t beforehand been potential with normal magnetic couplings, so as to harvest the full potential of the High Hot technology.
The High Hot coupling is not seen as a standardized shelf product, but as an alternative as custom-built by which is optimized for particular functions. Therefore, further growth might be made in shut collaboration with new partners.
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