Technical data

5.5. Programmer module (optional)
5.5.1. General information
The programmer module PGM-30 is used for a timer-controlled
pre-programmed process (freeze-drying program).
A freeze-drying program is divided into several sections. Every
section of the program has set values for the phase, the section
time, the shelf temperature, the vacuum, the safety pressure and
dT freezing/drying. The PGM-30 can store up to 30 individual
programs. Up to 32 sections can be assigned to each program. A
program has to comprise a minimum of 3 sections.
When the programmer module executes a freeze-drying program,
it executes the created sections one after the other until the last
section is completed. The defined set values for the shelf and the
vacuum are node points that are used by the programmer module
to calculate a linear function (ramp) with the corresponding
gradient. This means that the set value does not change suddenly
at the transition from one section to the next. Instead it has a
steady ramp.
Fig. 30 The programmer module uses the section time and the set values of the
current section and of the previous section and calculates a linear function (ramp)
for the shelf temperature and the vacuum in the drying chamber.
The first section of a program is always “loading”. In this section,
the start values for the calculation of the function and for the shelf
temperature are defined. In general, the room temperature is
stated. If the product is pre-frozen (process B, separate freezing
and drying outside the ice condenser chamber), the corresponding
product temperature should be stated. Section 2 and all other
sections can be used for freezing, main drying and final drying,
though it is not possible to switch phases. This means, for
example, that the freezing phase cannot be selected after a main
drying section.
The time for warming up the vacuum pump (warm-up phase) is
automatically determined by the programmer module during the
freezing phase. When the vacuum pump warms up, the freezing
phase (section time) is not affected. The pressure control value is
closed when the PGM-30 activates the vacuum pump during the
Operating Manual Freeze Dryer ALPHA 1-4 LSC / ALPHA 2-4 LSC LSC Control System • 55