The SGM Electro-Permanent Lifting Magnets are designed to be activated and de-activated by the sole action of an electrical current running only a few seconds. This is achieved by reversing the polarity of one permanent magnet usually made of Alnico ("reversible magnet") while also adding the constant force of a second set of permanent magnets usually made of Ferrite ("static magnet"). The two magnets are arranged so they can combine their magnetic forces into the load to lift it (operating phase) or, to short-circuit their magnetic forces to release the load (resting phase). As mentioned above, the passage from the resting phase to the operating phase is achieved by applying a very short current impulse which reverses the polar orientation of the " reversible magnet"; therefore there is no use of any electrical current throughout the operating phase.
SGM's Electro-Permanent Lifting Magnets for billets are specifically suited for loading and unloading trucks. Some of the benefits of using an electro-permanent magnet is the fact that there are no accidental drops of the loads as a result of power failure or cable interruption. Because of this, a special recommendation for the use of electro-permanent magnets is made for locations where sudden interruptions of main electrical power may happen inadvertently. This, combined with the fact that unlike electro magnets, electro-permanent magnets do not generate heat when energized, makes the electro-permanent magnet technology easier to maintain.
Specifically engineered to meet high demands and high duty cycles, SGM's Electro-Permanent Lifting Magnets for Horizontal Eye Coils result in the best solution to optimize the storage are on floor surface by allowing up to 90% of floor usage, compared with 40-60% of floor usage by using mechanical hooks.
With the use of the electro-permanent lifting magnet for eye horizontal coils the approach and surface contact with the coil is maximized, eliminating typical damages caused to the coils. Customers receive the exact coil lengths they requested.
Unlike mechanical tongs, electro-permanent magnets are maintenance free as there is no heat generation inside the magnet and no moving mechanical parts; they also do not present risks of oil leakages on coils.
SGM'S Electro-Permanent Lifting Magnets for rails are designed to handle rails up to 480 feet in length. With almost zero generation of heat, there are no limitations in duty cycle. This allows the operator to constantly operate the magnets without having to stop to allow the magnets to cool down. With an SGM electro-permanent lifting magnet, the operator has no need to get in contact with the rails neither to cross and stay by them. The magnet system is operated from a safe distance using radio control.
Some advantages of SGM'S Electro-Permanent Lifting Magnets include:
• They do not generate heat when energized.
• There are no limits in length of rail to be handled.
• Radio control operation.
• Irrelevant residual magnetism left in the rails.
• No accidental drop because of power failure.
• Electronic controllers are less sophisticated, easier to maintain.
• Operators' safety is increased by remote control and no accidental drop.
SGM, by working closely with the steel industry, has provided throughout the years different tailor made solutions for steel plates from 3 to 16 feet in width and up to 80 feet in length.
One of the benefits of the electro-permanent lifting magnets is that they are independent from external energy sources, there are no accidental drops of the load as a result of power failure or cable interruption.
Also, with SGM's patented Flux Measuring Device (FMD), the safety conditions under with the electro-permanent lifting magnet works are increased exponentially. This device verifies, before lifting, the contact conditions between the surface of the load the magnet polarities, making sure that the load is completely attached to the magnet to provide a safe ride.
The Electro-Permanent Lifting Magnet solution for slabs is specifically suited for loading and unloading slabs from vessels. Since 1996, more than 50 magnets for slabs going from 10 to 45 tons have been supplied.
The typical average time per shift for moving a slab is 4 minutes with only one person in the operator crane cabin and one person inside the vessel for guidance when view is restricted.
Since it requires just a few seconds to grip and release a slab, during 2008, at Dongkuk Korea, the use of SGM Electro-permanent magnets permitted the loading of 15 slabs in an operation that lasted one hour. This results in an average of 300 tons of slabs stowed on board each hour.
The Electro-Permanent Lifting Magnets for vertical eye coils are the best alternative to mechanical tongs. They eliminate the damage that in many occasions is caused by the mechanical lifting mechanisms. Also the electro-permanent lifting magnets increase safety of the operators by reducing the need to check for wear or tear on mechanical tongs as well as eliminating the drop of a load upon power failure.
Since 1996 more than 35 electro-permanent lifting magnets for vertical eye coils have been sold, going from 10 to 50 US tons.