Technical data

3.3. Separate freezing and drying outside the ice
condenser chamber (process B) with sealing
device
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 unit and the vacuum pump are activated via the
control system to pre-cool the ice condenser and to warm up the
vacuum pump. The valve is closed during the warm-up of the
vacuum pump. In case the unit is not equipped with an
electromagnetic pressure control valve, we recommend using a
manual stop valve. Without such a valve, the vacuum pump
cannot be warmed up.
The rack is set onto the base plate or onto the intermediate valve
with a base plate.
The sealing device is used to seal injection bottles under vacuum
or inert gas with serrated rubber stoppers. Depending on the type
of sealing device, the bottles are sealed on 1 to 2 shelves or on 1
to 4 shelves. To do this, the shelves are moved against each other
by a pressure plate using a spindle.
The height of the pressure plate must be adjusted according to the
height of the bottles. To do so, the threaded pin for the height
adjustment is removed. The threaded rod is screwed into the lower
shelf until its slotted head is on the same level as the rack (upper
edge).
Then the pressure plate is fastened with the threaded pin in such a
way that it will rest on top of the rubber stopper or slightly above it.
When using two or more shelves, every additional shelf is set
directly onto the rubber stoppers or slightly above them, just like
the pressure plate.
Instead of the stopper, the vacuum-tight rotary leadthrough is put
into the internal ground-in connection of the drying chamber.
Before the insertion, 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.
In order to seal the bottles, the shelf must be completely filled. For
small quantities, at least three spacers must be distributed evenly
on each shelf (according to the height of the bottles with inserted
rubber stoppers).
Suitable spacers are available upon request.
22 • Description of the Freeze Drying Processes Operating Manual Freeze Dryer ALPHA 1-4 LSC / ALPHA 2-4 LSC