Heidolph Synthesis 1 - Manual (Page 98)

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• Open waste cube and load with beaker. Mechanically close waste cube.
• Open base valves in reaction vessels (refer to Chapter 2.1.6). Evacuate waste
cube (e.g. start vacuum pump).
• Contents of reaction vessel now is drawn-off via filters and collected in beaker.
• Connect waste cube with atmospheric pressure (turn vacuum pump OFF)
• Close valves in reaction vessels (refer to Chapter 2.1.6).
• After having separated product from resin, remove beaker from waste cube
and fit test tube rack in waste cube. To this end squeeze grip zones of rack
and load rack, still holding the marked areas squeezed. Mechanically close
waste cube. From this point on proceed as described.
14. Use condensation zone
Running above boiling point of the reaction fluid, vapor may be separated in a
condensation zone. To this end connect condensation zone to coolant circuit or a
recirculating cooler as described in Chapter 3.1.
15. Use heating zones with recirculating cooler (low
temperature)
Working with reactions at temperatures below ambient, use an external recirculating
cooler for the conditioning zone. To this end connect recirculating cooler to
conditioning zone as described in Chapter 3.2 before starting work.
When working at temperatures below freezing, expect significant accumulation of ice
on the reaction block. Ice impedes view and makes item slippery (handle with care) !
Never attempt to work with item at temperatures below freezing in absence
of protective gas atmosphere. Locate item in drip pan and fill with
protective gas.
Temperatures below freezing also may be run by the different heating zones.
Coolest zone is close to the coolant entry port (e.g. zone 4); rise temperatures in the
following sequence: 4 - 1 - 2 - 3. (Using coolant entry port in zone 3, use 3 - 2 -1 - 4
sequence). Different temperatures are reached by heating "against" coolant action.
To this end select temperatures and start heater as described in Chapter 10.2 and
10.3.
Having worked at low temperatures and switching over to high
temperatures requires to drain all of the coolant from its passage.