Traditionally, bulk materials have been conveyed by inefficient pneumatic conveying
systems, and modern material handling plants have a need for more efficient conveying
systems to reduce power costs. However, power consumption savings do not stop with the
cost of electricity. There are also many other benefits associated with lower power
consumption.
The most important differences between dilute and dense phase are: material and air
speed and loading ratio of material.
In the dilute phase large amount of air is needed at low pressures and relatively high
velocities. High velocities is a disadvantage of the system, because some materials that have
to be transported are very easy degradable and also the wear of the pipes has to be considered.
By definition, dense phase pneumatic conveying simply means using a small amount of air to
move a large amount of bulk material in closely-associated slugs through a conveying line,
much like extruding. Unlike dilute phase conveying systems that typically use larger amounts
of air to move relatively small amounts of material at high velocities in suspension, dense
phase offers the enormous advantage of efficiently "pushing" a much denser concentration of
bulk solids at relatively low velocities through a conveying line.