Operation With Inert Gas; Ventilation / Breaking The Vacuum In Case Of A Power Failure - Binder VDL Series Operating Manual

9.10.2

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.
Following evacuation, an inert gas, e.g., nitrogen, is led into the inner chamber via the connection
"GAS/AIR" (4) or the optional connection "GAS/AIR 2" (5) until pressure compensation with the atmos-
phere occurs. Depending on the individual application, you can perform a second evacuation and repeat
the inert gas flooding.
When the inert gas fine dosing valve is open, a maximum of approx. 0.6 m³/h gas flows into the inner
chamber. The introduction of inert gas by under-flooding in the lower region of the inner chamber rear
wall and the extraction at the inner chamber ceiling allow an effective inert gas flushing.
9.10.3

Ventilation / breaking the vacuum in case of a power failure

The emergency ventilation is intended for the case of a completed drying process
To be able to open the chamber in case of a power failure, remove the "Manual ventilation" plug (7) for
emergency ventilation, which is located on the chamber rear.
As long as there is a vacuum, never try to open the oven by force.
Make sure that the drying procedure is complete before breaking the vacuum. Otherwise, you
should wait for the power to return to continue the drying procedure.
Explosion hazard through the formation of an explosive atmosphere in the pres-
ence of hot surfaces.
Serious injury or death from burns and / or explosion pressure.
∅ Do NOT remove the "Manual ventilation" plug, as long as the drying process is still
running.
VDL (E3.1) 06/2020
DANGER
DANGER
). Inert
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