Mr. Banergee,

The pipe conveyor will generally be more expensive.

Are there considerations that might favor the pipe conveyor? Say:

- tight horizontal curves that are feasible for the pipe conveyor but may require multiple flights for the conventional

- customer preference for which they are willing to pay a premium.

- etc.

Horizontal curves at a pipe conveyor are less complicated, complying to the radius of curvature constraint equations against overstress at the outer fibers, buckling at the inner, and inward collapse of the pipe section.

Horizontal curves at the conventional conveyor are more complicated. Besides the radius of curvature constraints to control outer edge over-stress and inner edge buckling there are the belt wander calculations to predict and limit the lateral movement of the belt. Belt wander calculations involve the load and direction vector, a sum of the gravity loads of the belt and material and the inward radial load due to tension. This is complex in that it varies with load and tension and requires an accurate and thorough conveyor tension analysis for the total range of tension and load variations at every point along every curve. The banking (super elevation at the inside of the curve) of the idlers creates the offsetting vector so that belt wander occurs to both sides of the belt centerline as desired. All of these considerations, along with tension control (by booster drives in various control algorithms) will dictate the allowed horizontal radius of curvature.

There is also the issue of higher power to drive the pipe conveyor but in this case a lowering application, it may no be such a big issue.

In any case, it is complex and "you should not try this at home". You should employ the experts who are very good at solving these problems and reducing the operation to clear instructions for reliable field operation.

At Dos Santos International we will be happy to do this work for you on a consulting basis.

Joe Dos Santos ■

I think pipe conveyor belt is more expensive than trough conveyor belt with horizontal curve.

As Joe said, it is complex, I also think you should employ experts who are good at solving these problems. ■