Fluidized bed drying/coolingfor polymers and plastics
Since decades our fluidized bed drying
technology is setting standards in the field
of polymer applications because of:
▪ Gentle drying on a low temperature level
▪ Low consumption on thermal and electrical energy
▪ Applicable for a wide range of products ▪ Compact design ▪ Low
investment costs ▪ Fully automatic operation ▪ Easy Cleaning
▪ High line capacities ▪ Corrosion resistance
For the primary drying of polymers, many
of which are temperature sensitive, choos-
ing the right drying method is of utmost
importance for the final product quality.
Due to the typically high level of moisture
evaporation, it is also desirable to utilize
an energy efficient drying process in com-
bination with compact construction of the
installation. A fluid bed dryer with heat ex-
changers integrated in the fluidized layer
is ideal for such requirements.
This is due primarily to the capability of
the fluid bed particles to transfer large
amount of heat at low temperature level
together with exact temperature control.
The double stage fluid bed drying system
fulfills all requirements for the desired final
product quality.
The implementation of internal heat ex-
changers in the fluidized layer is at the
Common used fluidized bed dryer types
VDC Vibrated Dryer/Cooler (single mass)
VDC Vibrated Dryer/Cooler (double mass)
DDC Direct Dryer/Cooler (stationary)
HDC Heat Exchanger Dryer/Cooler (stationary)
SGS Spray Granulation System (direct or indirect heating)
condensate
dry HDPE
cooling media
hexan
steam
condensate
steam
wet HDPE
�uid bed dryer
gas heater
recycle gas
scrubbing condenser
cyclone
Flowsheet of a dryer type HDC with solvent recovery
Equipment criteria:
▪ High operational availability ▪ Closed gas loop with solvent
recovery ▪ Pressure resistant and gas tight design ▪ Low energy
consumption due to inter-
nal heat exchangers in the fluidized layer
▪ High alloy steel material available ▪ A special feed
distributor for the wet
product, outside of the drying cham-
ber makes inside rotating spreaders
not necessary
same time minimizing respective gas
flows and thereby reducing convective
energy losses and increasing thermal dry-
ing efficiency.
These are the main reasons that the fluid
bed principle has been successfully ap-
plied in polymer application especially
when compared with other systems, such
as flash and rotary dryers.
For the drying and cooling of extruded
pellets as well as drying with heat treat-
ment (crystallization) of special polymers
ANDRITZ SEPARATION offers tailor-
made solutions.
To reach the necessary process reliability
it is in most cases necessary to do granu-
lating tests in our pilot plant test facility.
For product research and customer spe-
cific tasks our well equipped test facility
is available, including its highly qualified
personnel and a modern analyzing labo-
ratory.
The scope of our services includes basic
engineering, detailed design, job handling
and contracting, fabrication, supervision
of erection and start-up of single pieces
of equipment through complete systems.
Product references
▪ Polyethylene (HDPE) ▪ Polyvinylchloride (PVC) ▪ Adipic Acid
(AA) ▪ Acrylonitrile-Butadiene-Styrene (ABS) ▪
Polymethylmethacrylat (PMMA) ▪ Polyacrylamid (PAA) ▪
Polyethylenterephthalat (PET) ▪ Polypropylene (PP) ▪ Terephthalic
Acid (PTA, QTA) ▪ Polycarbonate (PC) ▪ Polystyrene (EPS)
