Powered Conveyors become essential for long horizontal transport, for applications with significant inclines or declines and where a high degree of automation is required such as merging, diverting and sorting.
Powered Belt Conveyors
Here the product is carried fully by a moving belt, which is supported by either a sheet metal slider bed or rollers mounted in the frame.
Used for transportation of products from one level to another, and for horizontal transport.
Advantages
Most practical and economic means of transporting goods from level to level
Most inexpensive of all powered conveyors
Lowest cost/metre powered conveyor
Highest throughput capacity and speed
Lowest noise rating
Handles widest range of goods (bags, parcels, boxes, sacks)
Maintains gaps and orientation
Many belts to suit applications
Very safe
Can handle declines/inclines up to 30 degrees
Suits high volumes
Belt on roller options for heavier loads
Reversible
Disadvantages
Accumulation only by multiple indexing units
In manual operations they are more difficult to merge to or sort from
Curves expensive and require own drive unit
Spirals more compact – expensive
Not generally used in areas of side loading or unloading
Powered Roller Conveyor
Powered Roller Conveyors are mainly used for transportation with the ability to provide minimal accumulation. The carrying medium is rollers mounted in a channel frame. Power is transmitted by various mediums, which drive the carrying rollers.
Drive types include:
Flat Belt - Economic for straight runs
Round Belt - Necessary for curves
Padded Chain – Similar to Flat Belt
Narrow Belt - Low stretch, high strength for high speed accumulation
24v Rollers - Drive adjacent rollers and permit accumulation
Lineshaft - Drives curves, sorting devices and provides for low pressure accumulation
Advantages
Fast, effective horizontal transportation over long distances
Good for use in applications where products are side unloaded or loaded onto the conveyor, such as at merges or at sortation points
They offer limited accumulation with minimum line pressure Enable loads need to be re-orientated on the conveyor
Permits pop-up devices between rollers (stops, diverters etc)
Lower power requirements
Disadvantages
Not suitable for incline or decline use beyond about 5 degrees
Noisier than belt conveyors
Less flexible with the range of product that can be handled (belts more flexible)
Carter Holt Harvey 
