12
When sterilizing liquids, the temperature is measured with a
temperature sensor in the load. The condition for countdown of
sterilizing time is that both temperature sensors in the chamber and the
sensor in the load indicate the programmed sterilizing temperature.
Post-treatment
The purpose of the post-treatment is to normalize the temperature and
moisture content of the goods. All goods except liquids are therefore
exposed for a certain time to a vacuum below 70 mbar (a). After such
post-treatment. textiles may appear to increase in weight by about 1%.
This represents the normal addition of water that occurs during steam
autoclaving process.
Post-treatment of liquids that have been sterilized in open or half-
closed containers consists of a self-cooling period. During this period
the pressure and temperature are lowered very slowly until the
temperature is well below the boiling point of the liquid. This process is
speeded up by applying a slight vacuum to the chamber when its
pressure approaches atmospheric.
Pressure equalization from vacuum takes place by admitting
atmospheric air into the chamber via a filter that prevents bacteria from
entering the chamber. The efficiency of the filter is 99.998% for
particles of the order of 0.3 micron (0.0003 mm) in size.
The sterilizer door is kept closed by the door gasket until the pressure in
the chamber is equal to atmospheric pressure.
Process adaptation
A large number of factors such as type of goods, goods carrier,
packaging material, etc. affect the result of the process. The control
equipment offers a number of features that can be used to optimize the
processes to suit the requirements of different customers. For further
information, see "User-programmable functions" in the TECHNICAL
MANUAL.
NOTE: Liquids must only be processed in sterilizers which
have a program for this type of load.
To Next Page
Loading...
