SP VirTis BenchTop 2K, Руководство оператора

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Basic Operation VirTis BenchTop 2K, 4K and 6K
24 Revision 004, 12/09
© SP Industries, Inc. 2009
a. The condenser approaches its maximum low temperature.
b. System vacuum approaches a constant low pressure reading.
c. Product temperature is steady and close to shelf temperature (requires
use of a product probe).
d. Appearance of the product indicates the dryness ( i.e. , uniformly
powdery or fluffy).
e. The product probe reads near ambient temperature or the temperature
of the heated rack (if equipped with that option).
10. Switch off the vacuum and refrigeration systems. If running an automatic
cycle, press the
AUTO button to disable both systems simultaneously.
11. For manifold flask drying, close Quickseal valves and remove flasks. If using
a
vacuum concentrator, turn off the unit and close Quickseal valves. If using a
chamber or manifold shelves, break vacuum and remove the product.
12. If your system is still under vacuum, release vacuum by inserting the drain
plug into the drain fitting or by opening a Quickseal valve.
13. After removing all product, press the DEFR button to enable condenser
defrost. The defrost function allows ice to be lifted out of the condenser
without fully melting. A drain line is connected to a plastic quick-connect
fitting, which is then inserted into the drain receptacle on the front of the unit.
To open the drain, push the fitting into the drain receptacle. To close the drain
line, press the small gray release button on the top of the receptacle. The
fitting will pop out.
Note: The quick-connect fitting must be removed prior to freeze-drying, or else the
appropriate vacuum pressure will not be achieved.
14. Once the ice has melted away from the condenser, the ice can be removed.
Thoroughly clean and rinse the condenser with a mild detergent or baking
soda solution (to neutralize acids).
Note: Do not chip away at the ice, as this may damage the condenser.
15. The defrost system turns off automatically after an hour. To disable it
manually, press the
DEFR button.
Meltback
Products that have low freezing points are prone to meltback during freeze-drying.
Meltback is a term used to describe when the product melts or defrosts before
sublimation completes. The following suggestions may help to prevent meltback:
•
Decrease the volume and depth of the product.
•
Insulate the product container to slow down sublimation caused by an
ambient heat source.
•
Decrease the amount of product or number of samples connected.
•
Verify that the equipment is functioning properly and ensure that room
temperature is sufficient to assist the air-cooled refrigeration system.
•
Consider diluting the product with water.
For products that dry readily, alternative heat sources such as a heat lamp may be
used to expedite the freeze-drying process.