what is the percentage of moisture content?

I have seen vibrating feeder for iron ore concentrate with moisture content of about 10%, but:

that is installed under circular reclaimer and works as a vibrating conveyor or chute not feeder under hopper. ■

I installed 15 EM FEEDERS on limestone quarry. FIFTEEN of them in a row actually. the EM FEEDERS ere the live bottom under 4' x 4' drop holes in the huge outdoor whse storage shed and stored limestone was pushed into the holes by wheel loaders. The EM FEEDERS discharged onto a very long wide belt feeder which loaded there ships here.

Small, shallow hopper arrangement above these feeders, properly designed to properly hold the material back vs FLOOD onto the conveyor.

GEORGE BAKER Moderator ■

Dear Mr. Baker,

would you please explain EM feeder?

and

what about moisture content? ■

see above message please.

Moisture in small percentages are not normally problematic. ■

Originally Posted by George Baker

see above message please.

Moisture in small percentages are not normally problematic.

I don't think moisture content about 10% is low, is it?

As you can see in first thread the discussion is about vibrating feeder for stick materials.

Is there any rule for the percentage of moisture content which vibrating feeder can be used? ■

The flow properties of bulk materials should be quantified for equipment design, rather than just described as ‘Sticky’ or ‘cohesive’. Generalisations can be misleading, but damp and wet bulk products of a fine composition tend to adhere to contact surfaces and consolidate to high shear strength, so wall friction and shear strength measurements can provide a guide to the form and geometry of equipment that may be suitable. Feed screws of a clog resisting design are effective in handling bulk materials that exhibit high surface adhesion characteristics and can provide a large and predictable ‘live flow’ area to serve at the outlet of a hopper, but these are normally used with hoppers that have relatively steep walls to generate mass flow, as shallow hopper walls tend to hold material, at best, to a funnel flow regime and are likely to give rise to the retention of residue of poor flow products in corners. Screw feeders also offer excellent containment and are positive displacement devices, whereas Vibratory feeders operate on a phenomenological basis, so their performance is, at best, material condition dependent and they require calibrating for a given output with a specific condition of the bulk material. To balance these, and other possible shortcomings of noise, fatigue and resonance with associated equipment, vibratory feeders are easier to clean and are of relatively simple construction and they are widely and successfully used at the extremes of high outputs of abrasive products and for tiny discharge rates. ■