Magnetic coupling at elevated temperatures

Magnetic couplings are used in many functions inside pump, chemical, pharmaceutical, course of and safety industries. They are typically used with the aim of decreasing wear, sealing of liquids from the surroundings, 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 build up with Neodymium magnets to have the ability to get the highest torque density as attainable. By optimizing the diameter, air gap, magnet size, variety of poles and choice of magnet grade, it is possible to design a magnetic coupling that fits any utility in the range from few millinewton meter up to several hundred newton meters.
When solely optimizing for prime torque, the designers usually tend to forget contemplating the influence of temperature. If the designer refers again to the Curie point of the individual magnets, he will claim that a Neodymium magnet would fulfill the necessities up to greater than 300°C. Concurrently, you will need to embrace the temperature dependencies on the remanence, which is seen as a reversible loss – typically around 0,11% per degree Celsius the temperature rises.
Furthermore, a neodymium magnet is under pressure during operation of the magnetic coupling. pressure gauge weksler ราคา means that irreversible demagnetization will happen long earlier than the Curie point has been reached, which generally limits the use of Neodymium-based magnetic coupling to temperatures under 150°C.
If greater temperatures are required, magnetic couplings manufactured from Samarium Cobalt magnets (SmCo) are sometimes used. SmCo just isn’t as strong as Neodymium magnets but can work as a lot as 350°C. Furthermore, the temperature coefficient of SmCo is only zero,04% per degree Celsius which implies that it might be used in functions the place performance stability is required over a larger temperature interval.
New era In collaboration with Copenhagen Atomics, Alfa Laval, Aalborg CSP and the Technical University of Denmark a new era of magnetic couplings has been developed by Sintex with support from the Danish Innovation Foundation.
The function of the project was to develop a magnetic coupling that could increase the working temperature space to reach temperatures of molten salts around 600°C. By exchanging the internal drive with a magnetic materials containing a higher Curie level and boosting the magnetic subject of the outer drive with particular magnetic designs; it was possible to develop a magnetic coupling that began at a lower torque level at room temperature, but only had a minor discount in torque stage as a perform of temperature. This resulted in superior efficiency above 160°C, regardless of if the benchmark was against a Neodymium- or Samarium Cobalt-based system. This can be seen in Figure 1, the place it is shown that the torque stage of the High Hot drives has been tested up to 590°C on the inner drive and nonetheless carried out with an almost linear discount in torque.
nuova fima pressure gauge ราคา shows that the temperature coefficient of the High Hot coupling is even decrease than for the SmCo-system, which opens a decrease temperature market where performance stability is important over a larger temperature interval.
Conclusion At Sintex, the R&D department is still developing on the technology, however they must be challenged on torque level at both different temperature, dimensions of the magnetic coupling or new applications that haven’t beforehand been attainable with standard magnetic couplings, to find a way to harvest the full potential of the High Hot technology.
The High Hot coupling is not seen as a standardized shelf product, but as a substitute as custom-built by which is optimized for particular functions. Therefore, additional growth shall be made in shut collaboration with new partners.
Share

Leave a Comment