
82 Aluminum Recycling
pieces landing on the inside of the belt are pulled away by the conveyor, improving
the likelihood that they will eventually fall off before causing any damage. Whether
concentric or eccentric ECS is more effective is a matter of debate.
Figure 5.15 also illustrates an alternative way of arranging the magnets in an
ECS. Most units use the arrangement shown at the bottom left, in which magnets
of reverse polarity are alternated. However, a more recent design (bottom right) by
Huron Valley Steel Corp. (HVSC) rotates the polarity by 90° in each adjacent mag-
net, rather than 180°. This produces a stronger magnetic eld at t