Separate Freezing And Drying Of Liquids In Flasks (Process B) - Fisher ALPHA 1-2 LDplus Operating Manual

Then the pressure plate is fastened with the threaded pin in such a
way that it will rest on or slightly above the rubber stopper. When
using two or more shelves every shelf is set directly on or with a slight
distance to the rubber stoppers as it is the case for the pressure plate.
Instead of the stopper the vacuum-tight rotary leadthrough is put into
the standard ground socket of the drying chamber. Before inserting,
the ground-in surface of the leadthrough is greased with vacuum
grease.
After completion of the drying process the lever of the rotary
leadthrough is turned to the right until a resistance is felt.
For the sealing of the bottles the shelf must be completely filled. For
small quantities at least three spacers must be evenly put on each
shelf (according to the height of the bottles with inserted rubber
stoppers).
The appropriate spacers are available upon request.
3.3. Separate Freezing and Drying of Liquids in Flasks
(Process B)
Possible water residue is removed from the ice condenser chamber.
The drain valve is opened so that the water residue can drain off. The
ice condenser chamber should be wiped out if necessary.
The refrigeration compressor and the vacuum pump are activated via
the control system to start the pre-freezing of the ice condenser and
the warming-up of the vacuum pump. The valve is closed during
warming-up of the pump. In case the unit is not equipped with an
electromagnetic pressure control valve we recommend to use a
manual stop valve. Without such a valve the vacuum pump must not
be warmed up.
Several manifolds and mountable drying chambers with several
connections for rubber valves are available for the drying process
outside the ice condenser chamber (see accessories catalogue). The
drying chamber with connections for rubber valves is mounted directly
to the sealing ring of the base plate. Manifolds with outer ground joints
NS 45/40 are connected via the ground-in socket of the acrylic lid.
In order to ensure a vacuum-tight connection and to simplify the
removal of the named accessories the ground-in surface must be
slightly greased with vacuum grease before use. The manifold or
drying chamber is mounted afterwards and turned by 360° for an even
distribution of the grease.
The ground-in surfaces have to be cleaned and greased before every
further mounting of accessories.
Before the drying process can start it is necessary to check that all
valves are closed.
Description of the Freeze Drying Processes • 21
Operating Manual Freeze Dryer ALPHA 1-2 LDplus