The PROCESS RETURN AIR TEMPERATURE displays the air temperature as it leaves
the drying hopper. If this temperature is above 150°F, an aftercooler is required.
By pressing the DISABLE or ENABLE the operator disable or enable this feature of the
dryer.
This feature is used to prevent the over drying of the plastic resin in the drying hopper.
At this point the operator has the choice of pressing
MAIN MENU, DRYER MENU, or
MORE to access the screen 2 of 2 of the OVERDY PROTECTION for adjusting values.
SET BACK VALUES;
The SETPOINT is the secondary drying temperature set point. This is the temperature at
which the drying temperature will be reduced to after a certain delay time and when the
return air temperature has exceeded its set point..
The
TEMP is the set point for the return air temperature of the drying hopper. When the
return air temperature exceeds this value, after a certain delay time, the process temperature
will be reduced to its secondary value (SETPOINT) to eliminate over drying of the plastic
material.
The
DELAY is the time which will take for the dryer to switch the drying temperature set
point from primary drying temperature to secondary drying temperature or back to the
primary drying temperature set point.
SET UP TEMP;
The SETUP TEMP is the secondary temperature setting for the return air temperature. When
the return air temperature of the drying is lower than this set point, after a certain delay time,
the process temperature set point will switch back to the primary drying temperature set
point.
Once the parameters have been set for the drying process, the operator can return to the
DRYER MENU, MAIN MENU, or BACK to the screen 1 of 2 of the OVERDRY
PROTECTION.
Setting Values
By pressing and holding the numbers in the SET BACK DELAY button, the following
screen will be displayed:
Portable Drying/Conveying Systems Chapter 4: Operation 27 of 63