motors with fixed speed and, therefore,
the drying time is fixed, regardless of the
aggregates’ characteristics. However, more
porous aggregates should remain in the
drying environment longer so that all the
moisture can be removed and then heated,
according to the project. This happens
during the creation of the project in which
the aggregates are dried and heated in a kiln
until all the moisture is eliminated.
A new concept of an asphalt plant
drying system was developed to adjust the
aggregates’ drying time according to the
characteristics of those inputs, mainly due to
adhesiveness and absorbed moisture. To do
this, the engines that make the drying drum
rotate vary the speed of rotation, thanks to
a frequency inverter. With this technology,
aggregates that are more porous spend more
time receiving heat from the flame of the
burner for complete drying, while less porous
aggregates go through the dryer faster,
without altering the plant’s production.
Intelligent combustion system
Traditional burners applied to asphalt
plants use the air from the environment
(sucked in by an exhaust fan with constant
TECHNOLOGY
The latest combustion technology in plants accurately and automatically control the
optimum air-to-fuel ratio by supplying all combustion air mechanically through two fans: a
blower and an axial fan.
QUARRY SA | NOVEMBER 2017 _ 25