Operating instructions

3.1. Dryer
The dryer operates with dehumidified air, i.e. the air is not only heated but also
dehumidified before flowing into the drying hopper. This principle allows plastic
granules to be dried to a residual moisture content as low as 0.002 % (PET
granulate).
The dew point temperature of the dehumidified air lies between -55° C and,
depending on the set value, -35 to -28° C. The lower limiting value of the
dehumidified air is about 80° C due to the intake of water in the drying cells.
The dryer operates continuously, i.e. dehumidified and, if necessary, heated air
is produced continuously.
F
The dryer is designed for continuous operation.
The dryer operates with 2 drying cells; one of these cells is always in the drying
cycle while the other is being regenerated (max. 60 min.).
The dew point temperature is monitored continuously. The valve system
switches to the freshly regenerated drying cell only after the selected dew point
temperature has been reached. The humid drying cell is then regenerated. After
the cooling time the drying cell is ready for operation again. The valve system
switches to the freshly regenerated drying cell only after the moisture content of
the drying cell which is in the drying cycle has reached the setpoint value.
If a malfunction occurs in the drying cycle during the program run, regeneration is
not interrupted, but continues until the program end has been reached. This
guarantees that 1 regenerated drying cells is always available.
The air inside the switch cabinet is cooled by a cooling appliance for the
protection of temperature-sensitive components (if present, optional).
With the digital timer the dryer can be switched on and off at set times.
CTT 300
Functional description 3-2