Norhof LN2 /LAr transfer system
Liquid Nitrogen (LN2) or Liquid Argon (LAr) is used as the cooling medium and is taken from a storage vessel (Dewar) with low pressure (max. 300 mBar) and delivered (pumped) through a fill line to the application in a micro dosing way.
The Norhof 465 transfer system is designed to overcome the drawbacks of Cryogen under pressure in which a solenoid valve is used to switch the supply ON / OFF. You may compare the Norhof system with a water tap, but instead of giving water, it gently gives liquid Nitrogen or Argon, with a flow rate of 1 Liter/minute. The system can pump up to 5 meters above the pump itself
The reservoir Dewar can safely stand next to your working place. When you need a small amount of LN2 or LAr, the system is ready to supply by only pressing the button on the pump head. After pressing the button the system starts building a small over pressure, forcing the liquid gently to rise into the fill line, and fall into your little Dewar, or other small container. After pressing the button again, the system shuts off, and the flow stops.
The pressure above the liquid level inside the Dewar is built by heating a small amount of liquid in the bottom of the Dewar. With only up to 300 mBar of over-pressure, the liquid will gentle rise out of the rise pipe and fall into the fill hose. Because we evaporate some LN2/LAr to build pressure, there is no adding of ice inside the Dewar, such as with manual systems which use air from the environment.
When LN2/LAr is required, a small overpressure is generated by a small heater element in the LN2 /LAr, and liquid flows out of the system like water from a tap, without spilling, noise, vibrations etc.