6. Today’s Scrap Drum Technology Weak zones at the drum edges Drop zone at the “transfer point” Declining performance after start up (as they get hot, they lose strength) The prime evidence, missed “meatballs” Three major performance shortcomings:
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8. Weak Zones at the Edges Electromagnet cross-section Steel Core Width of the Drum Face Width of Field
9. Dead Zones at the Edges The result is less ferrous separation at the edges, missed metals and poor recovery. This area accounts for roughly 15 to 20% of the surface area of the drum. The wider the Drum, worse the problem. An Electro-Magnetic Scrap Drum
10. Dead Zones at edges for other drums Electro-magnet Transfer Zone This is another manufacturer’s radial design electro drum. The remaining paint indicates where the drum has less edge strength.
13. Weak at the edges Electro coil, a necessary component Steel core, it does the attraction work Electro coil “crowds out” valuable core width The only solution is to oversize the drum in width This solution is not cost efficient Space for the coil, an inherent weakness
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15. Drop Zone at the Transfer Point The transfer point has reduced magnet force and therefore “drops”. Coil crowds out valuable internal space This means lost recovery. Electro-magnet Cross-section Carrying Magnet Pick-up Magnet
16. Drop Zone at the Transfer Point The area between these coils (about here) can drop metal creating additional burden and lost recovery Electro-magnet Transfer Zone
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19. Loss of Performance due to heat rise: 60 to 70 percent of their initial strength Operating gap is effectively reduced from 10 to just 6-inches or less for best recovery. Losing recovery before noon, least effective during over-time, more hand sorting and higher waste
30. Advantages of Eriez P-Rex Drum Stronger, (at any distance!) Wider (less edge loss) Uniform strength over time (no electrical heat rise) Results: Better Recovery
31. The P-Rex & the “Green Bonus” (environmentally and financially “green”) Lower purchase cost (no transformer/rectifier to purchase) Lower operating cost (no transformer/rectifier to continually power and maintain plus no periodic rewinding of electrical coils ) Lower installation cost (no transformer/rectifier to install, wire and isolate)