Each product transported by air is first mixed with the air and then
separated from the air. Although both operations are difficult, it
is preferred due to its flexible structure.
While the mixing operation is performed by help of rotary valves,
loading stations and venture, the separation operation is performed
by means of filters. On the other hand, pneumatic means dust, dust
separation and absolute filtering.
Blowers are used as generator of air, the transport source; in other
words, the fans of low pressure high flow rate of air are used.
However it seems that the transport is performed by mixing process
pressure air with the product, it requires serious engineering
operation and experience. On the other hand, pressure and vacuum may
also be used in the pneumatic transport processes.
Each product to be transported pneumatically bears different
characteriStic. For this reason, density and efficient transport
pressure of each product differs. And this, in turn, differs ways of
transport. If you attempt to transport sugar on a line used for
transport of flour without any modification, your line is doomed to
fail as it may be expected normally. None of the equipment you use
may operate properly. If the process is designed correctly and it is
operated with proper instruments and equipment, you may transport
both sugar and flour on the same line after making parametric
changes in the automation system. This example shows necessity of a
serious infrastructure and concept of experience in the practice.
Dilute Phase
Pneumatic transfer is mostly preferred for granular and
power articles or products. The speed varies 12-25m/s
depending on the phase density of this transfer made by
air. Transport method in the pneumatic transfer is two
types, namely dense phase and dilute phase.
Transfer operation in the dilute face is performed by
vacuum or pressure. The transport operation is generally
performed in the pressure range of 250-600mbar. These
two methods should be diStinguished depending on the
process of these two methods.
Mechanical Transport
Although the Mechanical Transport seems difficult and
has a set of patterns, it is the most cost-effective
solution for electric power. Investment cost is high in
the long distances, but use of power is less. In
general, it is also used for transfer at fixed flow rate
volumetrically for all pneumatic transport operations.
Pneumatic transport is the most flexible transport
method compared to the screw spiral, band and chain
conveyor. Although many secondary instruments and dust
separation systems should operate together, it is the
most preferred transport system thanks to this flexible
structure.