Pellets will roll back on a normal conveyor if inclination is more than 12.5 Deg. You have to use chevron strips on belt to prevent roll-back. ■

Selection of conveyor speed, width, troughing angle is based on product to be handled and capacity. Conveyor will be designed for loading the belt to optimum profile for normal operation. Pellets are like rough marbles and have a small angle of repose. They can easily start rolling back if incline is steep. ■

Just heed what Vinayak is telling you. What can roll back will roll back! ■

It will be minimised only during starting as you are reducing acceleration of belt at starting. The actual factors responsible for rolling is internal friction factor between the particles and friction factor between particle & belt.

with regards,

C B Ray ■

Hello Sganesh..

I have found that iron ore pellets tend to run back at the start of feed and at the end of feed if the belt is more than 11 degrees, which is close to the 12.5 degrees previously mentioned.

Anyway, the situation is made worse by having a flat cental roll in the middle of the carry side. At low tonnages, there aren't enough pellets to pack together to stop roll-back. Loose pellets simply roll back.

So... what I do, is carry the pellets on 4 roll carry idlers (or even 2 roll)

The pellets roll to the centre of the vee and pack so as to stop roll back, even at fairly low tonnages. Much much better than 3 roll.

Cheers

LSL Tekpro ■

You have written that the conveyor rarely stops. (Please assume that material is continously fed and stopping of the belt is very very rare, that too with load).

Vriable speed drive can slow down the conveyor to keep loading uniform. Pellets will roll if inclination exeeds 12 Degrees. Safe to limit inclination to 11 Deg. Alternative is to use belt with chevron strips. You are already doing it. Use of normal belt t 14 Deg inclination for handling pellets is no no. ■