46
Vapor Pressure Above Ice
Temp.
(°C)
Pressure
(mbar)
Temp.
(°C)
Pressure
(mbar)
Temp.
(°C)
Pressure
(mbar)
Temp.
(°C)
Pressure
(mbar)
Temp.
(°C)
Pressure
(mbar)
0
6.11
-11
2.37
-21
0.94
-31
0.34
-50
0.039
-1
5.63
-12
2.17
-22
0.85
-32
0.31
-60
0.011
-2
5.18
-13
1.98
-23
0.77
-33
0.28
-70
0.003
-3
4.76
-14
1.81
-24
0.70
-34
0.25
-80
0.001
-4
4.37
-15
1.65
-25
0.63
-35
0.22
-5
4.02
-16
1.50
-26
0.57
-36
0.20
-6
3.69
-17
1.37
-27
0.52
-37
0.18
-7
3.38
-18
1.25
-28
0.47
-38
0.16
-8
3.10
-19
1.13
-29
0.42
-39
0.14
-9
2.84
-20
1.03
-30
0.38
-40
0.13
Adjustments to the vacuum level must be made for various freeze-drying conditions.
One factor to consider is the size of the sample and the heat from the shelves that is
being applied to the sample. Exact protocols must be determined by the user for the
specific samples that are being freeze dried.
When the vacuum control is set to operate at less vacuum (higher pressure), the ice
holding capacity of the collector may be decreased.
Shut Down
At the end of a run, or when enough condensate accumulates on the collector coil to
obstruct the flow of vapor to the collector chamber, the extraction freeze dryer should be
defrosted. Go to Home screen, press VACUUM, then press STOP to turn the vacuum
pump OFF. Then release system vacuum by opening the vent valve on the left side of
the tray dryer. Press COLLECTOR, then STOP to turn the refrigeration system OFF.
Defrosting
The following procedure should be followed when defrosting the collector coil:
1. The hot gas defrost function can be used to speed up the defrosting process.
Defrost can be activated as follows: Go to Home screen, press COLLECTOR
button, press Defrost Options, then press START.
2. To turn off Defrost: Go to Home screen, press DEFROST button, then press
STOP. The defrost function will turn off automatically if the collector temperature
r60⁰C or if defrost has been running for 2 hours.
3. If rapid defrost is desired, pour warm water over the collector coil.
Do not allow
the liquid to enter the vacuum port on the upper rear wall of the chamber.
