Automatic level control of liquid nitrogen in a Dewar flask
In many cryogenic applications, such as shrinking of shafts and bushings in LN2, freezing of components or biological samples, using of LN2 as a coolant in cold traps, calibrating of sensors in LN2, etc., it is important to maintain a constant LN2 liquid level. This is achieved with the LN2 level control of KGW-Isotherm. With help of our LN2 level control, it is possible to keep a constant level of LN2 between the minimum and maximum sensor inside the flask. The KGW LN2 level control can be connected to almost every LN2 container.
The LN2 level control operates as follows:
If the LN2 level is sinking below the minimum sensor, a signal will be sent to the level control system. The LN2 level control opens the 24V LN2 magnetic valve, which is located at the transfer siphon which is connected at the LN2 storage container. Because of the over pressure inside of the LN2 storage container the LN2 will be pushed out the container and passes through a transfer line to the working Dewar Flask. The LN2 will float the working Dewar Flask until the maximum sensor will be dipped into the LN2 level. The maximum sensor is cooled as a result and gives a signal to the level controller. This will switch off the magnetic valve power supply so that the valve closes until the LN2 level will sink below the minimum sensor. Then the process described above will be repeated again.