Some English coal mines installed the Naylor's Bottom Loading Belt at the working face. Colliers lashed the coal onto the bottom strand from a kneeling position. In those days that was considered the easiest way to get coal along the gob & off the face. Nip points were not so imporatant in the 1920's & 30's. The top strand was out of the way, up against the hanging.

If you look hard enough in the mining history you will find the way to route & load the belt as required. Good hunting.

Don't forget that if you can get the belt to carry in both directions then you are getting 2 belts for the price of 1: so why worry about belt stresses & all that fancy stuff? ■

Dear Mr. A R Singh,

You have mentioned two methods of loading. One on external face and another on internal face. The belt has only two faces so possibly, there will not be other alternative.

One needs to take care of following issues for any loading on return side:

1) The material loading on return run of belt would require creating sufficient head run between carrying run and return run, at the point of loading; because skirt board is to be installed and feeding chute is to pass through two runs of the belt conveyor.

2) The material on return run is to be unloaded when it is reaching near tail end. This would require the arrangement similar to fixed tripper type. This will also require large head room between return run and carrying run at that location.

3) In case the conveyor is equipped with drive unit at head end as well as drive unit at tail end, one has to be particular about choosing the diameter of pulleys. There may not be much distinction in the tension of carrying run and return run. The usual tension classification gets blurred. This may require all the return side pulleys like high tension pulleys or drive pulleys (from diameter point of view).

4) When the material is conveyed on the return run, one has to take a special care that the internal face of the belt is thoroughly clean before it is passing through various pulleys and particularly drive pulleys. This will require unusual way of installing the various scrapers (cleaners).

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. A R Singh,

Referring to your reply, I have to look for the information. However, at this stage I can mention following answer / possibility:

It is preferred that for pipe conveyor, the overlapping edges should be at the top, in vicinity of terminal pulley. So, if one wishes to have the overlapping edges at the top then the belt inner face would be within the pipe formation.

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 ■