Product is used extensively on conveyor applications. Installations seen have ranged from package handling for FedEx (25 – 50 HP) to coal conveyors WE (up to 700 HP). ■

You can contact these guys, it is a local company who specialize in magnetic couplings of their own design.

http://www.burgmann.com/nmb/ ■

Gary,

As the website states, the magnetic drive is a new invention (which sounds very attractive from a power loss point of view). If you are interested in its performance, I suggest you contact the Premcor plant in Lima, Ohio.

Or contact the Michigan power plant (one of the Detroit Edison facilities?). You should be able to get contact information from the manufacturer.

The order they received from the Navy suggests that it could be a good product.

Good luck in your search to improve your mine's performance - keep the salt flowing! ■

I believe I have noted on a prior posting to a similar question. The magnetic drive is more suited to pump acceleration than conveyor. The flux field is not strong enough for a constant torque application.

CDI had the magnetic drive people come and demostrate their system some years back. The concept is neat but the magnets are not powerful enough to meet the needs of the conveyor's constant torque systems without serious overdesign of the magnetic clutch.

Maybe things have changed? ■

They have changed their concept. Originally, they promoted the idea of locking the input to output once speed was achieved. Now they are transmitting by cutting lines of flux. The question is how much energy do you wish to dump in order to have such a device. Four percent would seem to be a lot.

Such a slip loss on a 100 hp motor would cost:

$$ = 100 hp x 4%slip x .746 kw/hp x 5000 hours/yr @ $0.10/ kwhr

$$ = $1492 / year where @ 8% discount rate & 15 year life

$$ = $13,025 over 15 years in rough terms with the given assumptions.

$$ = $130/hp.

The Magnadrive energy loss would pay for an inverter soft-starter ■