Fans are sometimes used for hot air as well as for aggressive, explosive, valuable, or flammable gases and gas mixtures. In these applications, a reliable seal between the drive and the impeller is essential. The non-contact power transmission from the drive motor to the impeller by means of a magnetic coupling ensures that the impeller shaft is hermetically sealed and that critical substances cannot escape into the environment at the point of power transmission.
Depending on the design of the fan, very high speeds of 10,000 rpm and more are sometimes achieved. In these cases, precise manufacturing and optimal balancing of the magnetic coupling are particularly important.
The dimensioning of the magnetic coupling is based on the torque required for power transmission. For particularly powerful fans, torques of 1,000 Nm and more are necessary.
In autoclaves, fans are used to ensure an even temperature distribution. Depending on the design, the drive motor of the fan is located on the outside of the autoclave and transmits the rotary motion to the fan impeller inside via a shaft. To prevent the hot air from escaping to the outside via the shaft seal, the use of a magnetic coupling is also recommended here, as it guarantees a reliable hermetic seal.
