7
Prewarm Settings:
The Firefly Curing System has a very flexible
prewarm feature which allows the user to set two
different levels of prewarm and cool-down.
These settings are accessed through the main
control kiosk by going to “Settings”
→
“Advanced Settings”
→
“Factory Setup”
→
“Zones”. Preheat settings for each zone are
shown in Figure 11.
Figure 11: Prewarm Settings
Cold Preheat:
This setting controls how long the zone will
prewarm after the dryer has been determined to
be cold. This is the longest prewarm time.
Warm Preheat:
This setting controls how long the zone will
prewarm after the dryer has cooled down, but has
not yet become cold. This is usually set shorter
than the cold preheat time.
Cold After:
This setting controls how long the heating
elements must be turned off before the dryer is
determine to be “cold”. This is the longest cool-
down time.
Warm After:
This setting controls how long the heating
elements must be off before the dryer is
determined to no longer be “hot”. This time is
shorter than the time for the dryer to be “cold”.
The prewarm settings are largely a personal
preference for each user, influence by how they
use the dryer.
For users with a large number of very short runs,
it is usually advantageous to have short preheat
times (5 – 10 seconds), and short “cold after”
and “warm after” times (10 – 20 seconds).
For users with a small number of very long runs,
it is usually advantageous to have longer preheat
times (10 – 30 seconds) and longer “cold after”
and “warm after” times (30 – 120 seconds).
In general, the longer the prewarm time, the
more closely the temperature profile of the first
product sent through the system will match the
profile of product after. However, the longer the
belt will stop at the beginning of each run to
execute the prewarm.
In general, the shorter the “cold after” and
“warm after” times, the more closely product
spaced widely apart will have matching
temperature profiles. This is because the dryer
will not be allowed to cool down as much
between widely spaced product. However, it will
result in the belt stopping more frequently to
execute the prewarm cycles.
