Re: Belt Feeder Surge Factors (Multiple Feeders)
I would have expected a properly designed belt feeder to provide a controlled, volumetric output with negligable surges??
Perhaps others can comment as I have only seen a small number of belt feeders in operation. ■
Use Your Brain...?
Designer,
In a clean ideal (fictional) material in a ideal laboratory set up yes you might find a perfect Belt Feeder that has no surges.
But on planet earth where I come from, in iron ore you will never get perfect feeding despite how good you think you can design a conveyor. 
If you have only seen a small number of belt feeders, then why comment...? ■
Re: Use Your Brain...?
Originally posted by jacksonc
If you have only seen a small number of belt feeders, then why comment...?
Because those I have seen handling wet coal act as volumetric feeders, and extract a nice smooth load. The only time "surging" has occured is when intermittant flow problems in the bin cause starvation in the feed, hardly the fault of the feeder. ■
Re: Belt Feeder Surge Factors (Multiple Feeders)
As we all know there are many factors which cause surging, ranging from internal material shear properties - to - hopper and chute geometry and parameters, etc.
A big cause of surge as I understand it - is the unpredictable way iron ore shears in lumps as it flows off the feeder. Those that have seen apron feeders can vouch for the type of surges which form as the material shears in big clumps at the discharge. I acknowledge that belt feeders exhibit a much more controlled and smooth discharge however surge does still exist.
Regardless of the details of what specifically causes the surging it is inevitable that we must design for surge (however significant) it particularly so with iron ore, (as opposed to wet coal).
Anyway, if any one can provide some higher level of understanding on surcharge factors for multiple feeders with "iron ore", I would be appreciative. ■
Re: Belt Feeder Surge Factors (Multiple Feeders)
Originally posted by jacksonc
A big cause of surge as I understand it - is the unpredictable way iron ore shears in lumps as it flows off the feeder. Those that have seen apron feeders can vouch for the type of surges which form as the material shears in big clumps at the discharge.
You overcome shear surges caused by poor flow bulk materials off the end of a belt/chain/apron feeder by incorporating what I know as a "picking rotor" at the discharge of the feeder. This smooths out the discharge to minimise surging. Well established technology. ■
Belt feeder surge factors (multiple feeders)
Can anyone tell me how much the surge factor will vary for a single conveyor being loaded by multiple belt feeders? Does it decrease by much? This is a typical scenario in a twin cell rotary car dumper application.
Normally a single feeder will produce a surge factor of approximately 0.8, however if mutliple feeders are used, what is the cumulative effect on surge? My guess is it would reduce substancially due to the evening out of undulations resulting from probability functions.
In theory I think there may be the potential for both postitive or negative superposition to occur on the outloading conveyor. Hense, altering the value of surge factor. Is this worst case possibility valid?
Hense for a design case, would I have to look at possible cumulative undulations (increasing surges) adding to each other as each feeder discharges?
For example:
What would the surge factor be on the outgoing conveyor from a series of Four (x4) identical 2.4 meter wide belt feeders, discharging onto a single outgoing conveyor assuming normal (not excessively high) chute heights and loading conditions? We are talking approximately total fed capacity of 5000 tph. See the image below.
Thanks!
King regards
Chris Jackson
Attachments
surge (JPG)
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