I ask why bother when its been done already? The reason I say this is because all they are essentially a finish dozer track that nests inside each grouser pad to eliminate plugging.

what you really have to do is design the bulk storage above the feeder and the conveyance away from the feeder- the other problem is we do not know what you are processing either and what size the material is that you are going to feed through it.

You would be amazed at how little power it takes to run an apron feeder as they are run through a gear box that is usually reduced down from 3450 rpm or less to x which is the speed of the final driven shaft which powers the sprockets which drive the apron itself. The average apron feeder is also capable of running in reverse as well.

The other problem that affects design choice is whether you are using electric power or hydraulic drive. please tell us/the board readers more. ■

greetings,

If you want that set of information you must decide how big a feeder you want to use for your application and the size of the material you are conveying. as it only takes a tiny apron feeder to move mountains of material.

As far as wear is concerned you have to measure wear by use of a template or to check wear versus original size and thickness- they do not wear very much at all. The driven sprockets and individual pads are heat treated for wear as a rule.

One case in point, the mine where I once worked had an small apron feeder an 18 by 48 inch apron feeder,that was under a 75 ton bin that fed 450 tons per hour to the screening plant.

We never replaced the apron-the only maintenance we did was occasionally replace drive chains, driven gears and roller chain from the gear box or an electric motor once in 22 years.

You need to tell us more if you want more help as far as product flow requirements, bin design etc. ■

There is a paper by Rademacher (?) of a Uni in the Netherlands.

Also..various people from the TUNRA, Uni of Wollongong (/) have written similar papers on feeder design eg AW Roberts et al.

The trouble is that they have a lot of variable and U need to know what values to use in these and this is where experience comes in.

U could look at the friction beteen the material and pans and based on speed and surface area...work out a ball park figure

Unless U work for an apron feeder manuafacturer, just ask them to design/quote one for U. They always make them robust.

Cheers

James ■

Look in the Renold Chain; Material Handling Chain Catalogue; Pages 66-104; Section 4; Conveyor Chain Designer Guide. Much more than enough. ■

Dear Mr. Ziggy,

I can only mention steps in brief to design apron feeder, because it is not possible to give lengthy information on forum. I understand you are referring to apron feeder and not to apron conveyor. Therefore, the reply is in context of apron feeder.

1) First you have to decide the allowable speed for apron feeder. This could be in the range of 15 fpm (0.075 mps) to 40 fpm (0.2 mps). The speed will depend upon the material characteristics, particularly lump size.

2) Decide the minimum width of skirt board to suit lump size.

3) Decide the required cross section of material in conjunction with selected speed and capacity. In this calculation you can consider, material cross section height about 75% of material cross section width.

4) Use the width as per calculation of serial number 3 or to suit the lump size whichever is more.

5) Adjust the speed to suit the final selected material cross section width and height.

6) Apron feeders always need variable speed drive. So, maximum of variable speed range should correspond to design capacity, which could be about 20% more than the guaranteed capacity. That means apron feeder will normally run below maximum range by certain margin. This provides room for selection of speed during field trials / setting.

7) The above information will enable you to choose the apron width skirt board height etc.

8) Estimate (assume) mass of chain apron etc as per your judgement. If this judgement goes wrong then you have to do the exercise again.

9) The material mass along with the chain and apron pan mass will be moving as a rolling element. Refer chain conveyor literature for rolling resistance of this mass.

10) If the apron feeder has inclination add for the lift resistance.

11) Calculate the material shear resistance below hopper outlet.

12) Consider about 4% extra resistance for terminal sprocket etc.

13) In case the apron pans are partially sliding below feed zone then add the resistnace for the same.

14) Add up all resistance. This will enable you to decide the chain pull, power etc.

The above information is for general guidance.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■

Further to my reply, I missed the skirt board resistance. This should be also added in the various resistances. In case if any minor resistance is missed, please take care of the same.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■

Dear Mr Ziggy,

Please try to get Allis Chammer guide book for the same. In the FORUM it is not possible to give .

Regards.

A.Banerjee ■