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 surroundings, cleanliness needs or as a security 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 find a way to get the very best torque density as potential. By optimizing the diameter, air hole, magnet size, variety of poles and choice of magnet grade, it is possible to design a magnetic coupling that fits any software within the vary from few millinewton meter up to a quantity of hundred newton meters.
When only optimizing for prime torque, the designers typically are likely to overlook considering the influence of temperature. If the designer refers back to the Curie level of the person magnets, he’ll claim that a Neodymium magnet would fulfill the requirements up to greater than 300°C. Concurrently, ความหมายของเครื่องวัดความดัน is very important embrace the temperature dependencies on the remanence, which is seen as a reversible loss – typically around 0,11% per diploma Celsius the temperature rises.
Furthermore, a neodymium magnet is underneath pressure throughout operation of the magnetic coupling. This means that irreversible demagnetization will occur long before the Curie level 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 made of 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 implies that it might be used in purposes the place efficiency stability is required over a larger temperature interval.
New generation In collaboration with Copenhagen Atomics, Alfa Laval, Aalborg CSP and the Technical University of Denmark a brand new era of magnetic couplings has been developed by Sintex with support from the Danish Innovation Foundation.
The purpose of the project was to develop a magnetic coupling that would 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 better Curie point and boosting the magnetic field of the outer drive with particular magnetic designs; it was possible to develop a magnetic coupling that started at a decrease torque stage at room temperature, but solely had a minor discount in torque level as a function of temperature. This resulted in superior efficiency above 160°C, irrespective of if the benchmark was in opposition to a Neodymium- or Samarium Cobalt-based system. This may be seen in Figure 1, the place it’s proven that the torque level of the High Hot drives has been tested as a lot as 590°C on the inside drive and still carried out 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 efficiency stability is important over a larger temperature interval.
Conclusion At Sintex, the R&D division continues to be growing on the expertise, but they have to be challenged on torque stage at both completely different temperature, dimensions of the magnetic coupling or new applications that haven’t previously been potential with standard magnetic couplings, to have the ability to harvest the full potential of the High Hot expertise.
The High Hot coupling just isn’t seen as a standardized shelf product, however as an alternative as custom-built by which is optimized for specific purposes. Therefore, additional development might be made in shut collaboration with new partners.
Share