The Hydrohansu-type rotating cleanflow magnet recently introduced by Goudsmit Magnetic Systems BV of Waalre (NL) was developed in collaboration with producers of top-tier food products. The driving force was a pressing need for removal of very fine iron (Fe), AISI 304 and 316L particles in the dairy industry, for products such as baby food, yet it is also suitable for use in the sugar and lactose industry. Rotating magnets prevent the accumulation of fatty powders on the magnetic bars and guarantee a high level of separation. The new magnet system is hygienically designed in accordance with the EHEDG guidelines and can be cleaned semi-automatically.
The single-piece, hydroformed housing is made entirely of grade 316 stainless steel and therefore has no dead ends, sharp corners or welded seams, which prevents bacterial growth. The complete system has a high quality surface finish (Ra ≤ 0.6 µm). The magnet rotor has pneumatically operated magnet bars, is mounted in the door and rotates on a bearing. To prevent product from entering the space between the rotor and the housing, it is fitted with a removable labyrinth air lock. A continuous, clean stream of air (+0.2 bar) feeds that air lock and blows from the inside towards the product chute. The use of rotating pneumatic magnet bars ensures that the powerful magnetic value (11,500 gauss) is in direct contact with the product. Tests have shown that in addition to separating Fe (99%) a high percentage of the AISI 304 and 316L particles are also separated.
The semi-automatic cleaning process can be performed during a production stop. After the rotor is released and pulled out manually, compressed air internally shifts the magnet packs to the cleaning position. This provides a quick, easy and safe cleaning method in which the metal particles are carried away. Moreover, the Hydrohansu –in comparison to previous versions of rotating magnets– no longer has any delicate loose parts. This results in a high level of efficiency and user-friendliness. Sensors ensure that all these steps can only be performed in the correct order.