Distance
Understandably, the more tubing in the system the bigger the pump needed to maintain airflow at the required force throughout its length. Over longer distances push is more economical than pull, so this may influence your choice between pressure- or vacuum-driven systems.
Vertical lift is not an issue in pneumatic conveying (a key advantage), but turns in the route do increase required power – a 90-degree sweep is equivalent to an extra 20’.
Density
The bulk density of your material obviously affects how much air is needed to move it (cubic feet per minute), and this determines the size and power of main components like vacuum receivers and pumps.
Most materials between 25-55 lb/cu ft convey easily. Heavier and lighter materials need bigger or extra equipment. Fine powders often need extra filtration inserted to suppress dust and consequently end up needing more powerful air sources like heavier materials. (Typical bulk densities can be found here: http://www.engineeringtoolbox.com/density-materials-d_1652.html.
Batch or Continuous
Some systems move material continuously, whilst others are called upon to deliver it in batches. It’s the maximum rate at which material has to move that determines the power required.
Other Characteristics
Some materials have sticky or clumping tendencies. To avoid packing occurring, these situations may need more power than free-flowing materials of the same density.
Dangerous materials are often best conveyed using a vacuum conveyor or dense instead of dilute phase – meaning there is more material moving at once but more slowly. Dense can also be a better choice for mixtures prone to separation. If you think your material has unusual or dangerous characteristics, make enquiries with an experienced installer such as http://www.aptech.uk.com/pneumatic-conveying/vacuum-conveying/.
Pickup
Is your pickup point a wand, bagging station, bulk bag unloader, docking station or adapter? Sometimes bespoke equipment is designed to automate steady and continuous material entry.
Destination
The equipment or process being fed is another factor – mixers, extruders, packaging equipment or whatever. For example, a loss-in-weight feeder needs fast refilling, and that may entail adjustment to the conveyor.
Headroom
30” of headroom is usually needed above a packaging or processing outlet, but if this isn’t available it’s still possible to devise a bespoke solution.
Environment
Humidity, climate and altitude can affect both materials and compression, so even geographical location may affect your final design.
