A simple way is to design a raising table at each fixed discharge point that flattens the lightly troughed belt. An angled flat plow, with a rubber blade, is dropped onto the belt at the table station where to discharge is needed.

There are other ways as others will advise.

Some key points:

1. Life of equipment - more money spent usually equals longer life. There are options.

2. How is feed programmed- can the flow be interrupted to allow a plow to deflect the flow stream. Dont want to have plow dig into rock charge -- plow will result in higher belt wear than other options.

3. Slower travel speed is better - 900 mm belt traveling at 0.5m/s does it

4. There are many mechanisms that can be made to work. Space restriction is another limiter on choices.

5. Does the discharge need to be from one or both sides of the belt?

6. A fixed location discharge articulating two pulley tripper system can be applied in conjunction with a articulating bifucated chute -- much more expensive than the plow but will not harm belt -- still needs programmed flow stream to allow pulley action ■

Dear Leo Grogan

In addition to method sugested by Mr Nordell you may have following options

1,0 Movalble plow .In this cas you can shift the plow to desired location

2.0 You can have shuttle conveyor

3.0 You may have movable tripper

Based on locations of feed and discharge points best possible option may be worked out

A R SINGH ■

Dear Mr. Leo Grogan,

You are dealing with very abrasive material. The material discharge zone is only 25 m. The travelling tripper would not be economical for such a short discharge zone. A better option would be to use reversible shuttle conveyor say about 14 m in length. This will enable you to discharge the material anywhere in the discharge zone.

In case if you are satisfied with only two number of discharge points, you can simply use one reversible conveyor.

Regards,

Ishwar G Mulani.

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

Author of Book : Belt Feeder Design and Hopper Bin Silo

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■

The information provided suggests; but does not confirm; that the belt might be loaded outside the 50m gallery & that the feeders will be used singly.

Usually, because of the feeder installation & maintenance requirements, the rock has to be removed laterally. If you use a shuttle conveyor about half your bins are dry while you fix a feeder. You cannot move the shuttle while men are working beneath! Exit shuttles.

Provided that the vertical curve can be accommodated you would get away with a tripper. The tripper lift length must be just less than half the bin dimension, whether this initially includes the skirted feed length or not. Since you have "several" feed points & if we can assume this to be minimally 3 then the tripper ascent distance will have to be less than 8m. Your stones are reasonably large & would limit the tripper angle to around 16 degrees.

A 600mm, or is it 650mm?, troughed belt would suffice so you could comfortably fit the tripper discharge chute into a low headroom.

100tph would be safe on a, 750 say, flat belt after the feed skirts & the belt speed would be slow enough to alleviate the belt ploughing damage phenomenon. Fixed ploughs do seem to be the optimum equipment. You can skirt along the full length & have tapering skirt sections ahead of gaps for discharge.

Travelling ploughs require similar trackwork to shuttle conveyors and trippers and & must sustain the material impulse from the trackwork paraphernalia. Otherwise they require fixed anchor stations, so why not have a set of already anchored ploughs?

Don't worry about chewing up a poxy little belt now & again. Energy resource considerations make equipment life expectations quite insignificant. Plough for today; tomorrows power cuts will give you all the maintenance time you need. ■

Plow does not move. ■