Sandwich belt high angle conveyors have long been known as the best solution for tight spaces where a steep lift is required to maintain a small footprint. However, applications are also quite common in which a large footprint is available, but a high angle is needed in just a small portion of the conveyor path. Because a sandwich belt system uses a wider belt to achieve the same conveying rate as a conventional conveyor at the same speed, in an application such as that described above, the question must be asked: Should you extend the tail of the sandwich belt, or should you break up the path into two separate conveyors, in which a narrow conventional conveyor discharges on to the wider Sandwich belt system?
For instance, a tripper may travel horizontally along the length of a dock to feed a perpendicular shiploader. In cases where the shiploader is at a considerably higher elevation than the dock conveyor, a standard tripper would require that the dock conveyor and dock be much longer than otherwise necessary, as its uplift would extend quite far back from its discharge pulley. Historically, the solution in this case would be to design a much lower-lift tripper, which would then feed on to a Sandwich Belt High Angle Conveyor. While this is a perfectly viable solution, which has been executed in the past as shown in Figure 2, it would be preferable to eliminate the conventional-to-sandwich transfer if possible.
The DSI Adder Snake (see Figure 1 and Figure 3), which is currently patent pending, solves the problem by swallowing the narrower conventional belt (Item 1), along with its material, into the two wider sandwich belts (Items 2 and 3). This allows the material to enter the sandwich belts with minimal disturbance and without the energy loss and additional equipment required for a standard transfer.
While the shiploader trailer arrangement is a very good application for the Adder Snake, the concept was originally born out of a requirement to elevate material from underneath a storage facility to a surface conveyor. A conventional solution would not work, as it would require the surface conveyors to go sub-surface. Discharging on to a high angle conveyor was an option, but the space under the storage facility was very tight, and accommodating even a very compact transfer station proved to be difficult. The Adder Snake solved both problems by allowing a high angle with no transfer.
The Adder Snake can also eliminate transfers along long overland systems that require high angles only in isolated areas. As a bonus, it can further serve the function of a booster drive at those points, reducing the overland belt tension. Uphill and downhill paths are equally possible.