Formeco Drester 120, Использование и обслуживание

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9.VACUUM GENERATOR (OPTIONAL)
9.1.
General description
Using vacuum inside the boiler lowers the boiling point of the solvents being distilled.
Vacuum distillation is used:

preferably for solvents with a boiling point above 160 °C;

obligatory with solvents with a boiling point over 200°C (the FORMECO distillation units operate at a
maximum temperature of 200°C);

when treating substances with a boiling point close to the auto-ignition point, for example mineral spirit
with a boiling range of 150-195°C and an auto-ignition point of 254 °C

when re cycling thermally unstable solvents, where the boiling point can be above the temperature where
the solvent decomposes (acidifies)

when the contaminants decompose or carbonize at the working temperature under atmospheric pres-
sure.
Vacuum distillation can provoke also undesired phenomena like foam formation during the boiling phase.
Furthermore maintenance will have to be done on the vacuum group as well.
Solvents with a boiling lower than 100 °C cannot be distilled under vacuum with a machine with an air
cooled condenser, because the solvents under vacuum will have such a low condensation point that complete
condensation cannot be guaranteed. In this case a water cooled condenser will have to be applied.
Manual vacuum: at the start of the distillation unit, the operator opens the manually the compressed air line
that goes towards the vacuum group. At the end of the cycle, the compressed air has to be closed manually
and the vacuum has to be discharged manually.
Automatic vacuum: at the start of the distillation unit the distiller activates automatically the vacuum unit.
At the end of the cycle, the compressed is stopped and the vacuum is unloaded automatically.
9.2.
Technical details vacuum group
Description U.M. RS120
Geometric capacity vacuum vessel litres 18
Dimensions (Length x Depth x Height) mm 600 x 250 x 400
Weight kg 15
9.3.
Connections
Connect the vacuum vessel ( 12 ) to the distillate outlet of the distillation unit, using an anti-solvent hose pro-
vided with the unit. Bends and curves in the connection piping have to be avoided. Connect the vessel using
the quick connector (
6 ).
The pressure of the compressed air feeding line should be 5 ÷ 6 bar ; the compressed air consumption is
about 30 ÷ 35 litres/min.

In case of a manual vacuum group, connect the vacuum group with a 6x8 mm tube through a pres-
sure reducer to the compressed air inlet (
5 ).

In case of an automatic vacuum group, connect the compressed air with a 6x8 mm piping and a
pressure reducer to the compressed air inlet of the machine (
3 ) and the outlet ( 4 ) of the solenoid
valve to the air inlet of the of the vacuum group ( 5 ) with the spiral tube provided with the unit.
Always verify the earth connection of the distillate vessel ( 12 ).
9.4.
Testing
Verify the proper sealing of the vacuum group, without loading solvent into the distiller:
1. Close the cover of the distillation unit and the inlet valves and outlet valves of the distillate (7);
2. Open the compressed air line and regulate the pressure at 5 ÷ 6 bar ; for the automatic vacuum group it is
necessary to set about 30 minutes on the distillation unit, to let the vacuum group run. Set the working
thermostat to zero.