Operator`s manual

VirTis BenchTop 2K, 4K and 6K Optional Components

Revision 004, 12/09 31

Liquid Nitrogen Trap

The optional Liquid Nitrogen (N

2(liq)

) Trap protects your vacuum pump from the

corrosive properties of acid and alkaline vapors, as well as the low temperatures and

organic solvents associated with the freeze-drying process. The trap is available in

both 2.8- and 5-liter capacities.

To Vacuum

Pump

Condenser

Vacuum bypass assembly with

lever-activated ball valves

To operate a liquid nitrogen trap:

1. Enable the condenser and wait for the system to reach operating

temperature.

2. Remove the plastic cover from the stainless steel vessel and add a small

amount of liquid nitrogen to the center well. If adding liquid nitrogen from a

tank, use adequate ventilation to protect from gaseous vapors.

Note: The liquid nitrogen will expand and bubble when it meets the warm center well.

Wear protective eyewear and gloves to avoid contact with skin.

3. Replace cover and wait one minute.

4. Open center well and slowly fill with liquid nitrogen (2.8 or 5 liters, depending

on capacity).

5. Open valves 1 and 2, and close valve 3 (see diagram above).

6. Enable the vacuum and wait until vacuum pressure reaches 100 mT.

7. Trap is now in operation. Liquid Nitrogen evaporates rapidly over time and

solvent is condensed. Check center well often and refill with liquid nitrogen as

needed.