Dear Mr. Horacio.

It seems you are referring to a 90 degree bent belt conveyor handling unit loads (baggage, packets, etc.). So, for this type of conveyors, there would not be external scraper, internal scraper, numerous pulleys etc. It may have only two pulleys, one at head end and one at tail end. How are you keeping the belt radially in position? Whether by special ribs etc.

The design for calculating tractive pull for such conveyor should follow the general method for usual conveyors. So, you have to calculate main resistance carrying, main resistance return run, pulley turning resistance, pulley wrap resistance, acceleration resistance by the material, package blocked somewhere temporarily and its sliding resistance, etc. The special features to keep the belt radially in position will result in to higher conveying friction coefficient, instead of usual value of 0.02 or 0.03.

I hope the above information may be of use to you to decide the modality of calculation, to suit your specific case.

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 ■