Breaking The Vacuum (Flooding); Ventilation After Completing The Drying Procedure (Flooding With Ambient Air Or Inert Gas); Operation With Inert Gas - Binder VDL Series Operating Manual

9.9

Breaking the vacuum (flooding)

9.9.1 Ventilation after completing the drying procedure (flooding with ambient air or
inert gas)
The duration of the drying procedure can be determined via the pressure display on the controller. When
the decreasing pressure reaches the set-point value, the drying process is completed. If the drying moni-
toring (chap. 12.7) is activated, a corresponding message is displayed.
To break the vacuum (ventilation) after completing the drying procedure, set the desired pressure set-
point to atmospherical pressure (chap. 10). The ventilation valve opens, and ambient air or inert gas flow
into the inner chamber.
Regularly the inert gas connection / ambient air inlet „GAS/AIR" (4) is used for ventilation.
Chambers can be equipped as an option with an additional inert gas connection / ambient air inlet
"GAS/AIR2" (5), which can be used alternatively. To do this, the controller function "GAS/AIR 2" serves to
close the valve of the standard connection "GAS/AIR" (4). Then the valve of the optional connection
"GAS/AIR 2" (5) is used for ventilation (chap. 11.2). This allows convenient switching when both connec-
tions are used differently (e.g., for inert gas and ambient air).
Ambient air is sucked in through the inert gas connection / ambient air inlet (4) or (5). The ambient air is
introduced into the lower part of the rear panel of the inner chamber and is evenly distributed in the inner
chamber. This supply of ambient air by under-flooding prevents turbulence of pulverized drying material.
Following ventilation, remove the loading material.
If no further drying process is to be carried out, switch the chamber to standby mode on the controller or
pull the mains plug to switch off the chamber completely.
9.9.2

Operation with inert gas

When operating the VDL vacuum drying oven with inert gas, correctly follow the technical ventilation
measures, as described in the DGUV guidelines 213-850 on safe working in laboratories, issued by the
employers' liability insurance association (for Germany).
During operation with inert gas, the chamber is supplied with an oxygen displacing gas (e.g. N
gases in high concentrations are hazardous to health. They are colorless and almost odorless and there-
fore practically imperceptible. Inhalation of inert gases can cause drowsiness up to respiratory arrest.
When the O content of the air decreases below 18%, there is risk of death from lack of oxygen. Any gas
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that might escape has to be led out via good room ventilation or a suitable exhaust system.
Risk of suffocation due to high concentration of inert gas.
Death by suffocation.
∅ Do NOT set up chambers in non-ventilated recesses.
 Ensure technical ventilation measures.
 Respect the relevant regulations for handling these gases.
 When decommissioning the vacuum drying oven, shut off the inert gas supply.
Install a pressure reducer for inert gas operation. Set the pressure reducer to a pressure slightly above
ambient pressure. Ensure that the pressure reducer will open. Do not change this setting in order to avoid
perturbation inside the oven and release of big quantities of inert gas after flooding the VDL.
VDL (E3) 09/2019
DANGER
). Inert
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