Pneumatic conveying may be defined as a continuous and flexible transporting method for dry bulk particles through a pipeline by either a negative (suction) or a positive (blowing) pressure air stream.
Basically it consists of a tubing system in which a granular product is carried. Suction systems are commonly used for the recovery of products from bulk storage and transferring it to a new location a short distance away. Pressure systems are used when conveying products longer distances. In some cases benefits are gained by using a combination of suction and pressure systems.
The handling of powdered and granular product by pneumatic conveying was first used during the middle of the last century and is still an accepted practice in the majority of the grain and food handling industries.
The successful design of pneumatic conveying systems is largely provisional and owes a great deal to practical experience and empirical design curves and equations. Nevertheless design of pneumatic conveying systems is largely providing answers in the quest to better understand the behavior of air/product suspensions flowing in pipelines. Improvements such as the velocity control mechanisms have added gentleness to the product being conveyed.