# How do you calculate the chain tension required when compressing bulk material over a conveyor?

Bulk material is conveyed over a slat conveyor, and the material is leveled with overhead rollers while being transported in the conveyor to maintain an even material height. Most of these "levelers" operate at a surface speed that is much faster than the speed of the conveyor. However, one particular overhead roll serves to compress the material slightly and feed a machine downstream, and it operates with a surface speed close to the conveyor speed.

This particular roller operates at a constant speed, but the conveyor does not. As such, there are times when the roller has a faster surface speed than the conveyor, but other times when the roller operates more slowly.

Is there a way to calculate the effect of these external devices on the force or energy required to operate the conveyor? I am particularly worried about this last roller, since it seems to cause the most resistance to motion. I have been unable to find even empirical information on the effect of these rollers in standard chain pull calculation guides.

• drive that roller from the conveyor... then it will always match the linear speed... Commented Mar 12, 2019 at 16:15

$$E= 1/2 \dot {m}v^2= T_{belt}\cdot v$$