Surveillance

CryoSwitch Specifications
Switching supply system for transport containers

Application
CryoSwitch supplies a liquid nitrogen storage via two transport containers. The switching supply system supervises the filling of liquid nitrogen from a transport container and switches, if first container is empty, to the second full transport container.
CryoSwitch is used together with a second transport container, if the weekly supply of a transport container is no longer sufficient or a high supply reliability is demanded.

Structure

Description
CryoSwitch can be installed in a stainless steel cabinet. On the left and right from the cabinet the transport containers are attached. The changeover is effected via an electrically driven 3/2-way ball valve which is controlled depending on the filling pressure of the connected containers. The control and monitoring is carried out via a modular control system that can be integrated into the primary CryoServer control system. All pipe sections are equipped with safety valves. For local operating supervision pressure manometers for container- and system pressure are installed in the cabinet.
Status lights in the control system and displays on the CryoServer signal the operating status and enable switching functions. In case of power failure, the switching system can be operated manually.

Technical data

Operating pressure	bar	1,5
Operating temperature	°C	- 196
Width	mm	500
Height	mm	700
Depth	mm	210
Weight	kg	20
Electrical supply		24 VDC
Protection		IP 65

CryoSwitch 2.0 – Layout and function
Design depending on room classification:

• As standard a CryoValve is used, supplemented with the add-on components in stainless steel, prepared for wall mounting.
• For clean room requirements, the complete pipework is integrated in one stainless steel switch cabinet, the pressure indicators are integrated in the switch cabinet door and connected via tubes.

Functions:

• Standard: Control via CryoModul, optionally with CryoServer.
• The status lights of the illuminated pushbuttons are controlled separately:
• The key lights up continuously when the container is recognized as ‚filled‘
• When the container is selected and recognized, the button flashes in second intervals
• Two pressure limit values can individually be set for each container:
• Value 1 ,Switch-on value: If the switch-on value is exceeded, the container is recognized and displayed as „full“ (V: 0,7 bar)
• Value 2, switch-off value: If the value falls below the switch-off value, the container is recognized as "empty" and displayed (V: 0,5 bar)
• No container is detected under a pressure of 0.2 bar and this is displayed graphically (in the CryoServer) until the value 1 is exceeded.
• All switching functions are delayed by 2 seconds.
• An empty container has to be disconnected in order to be recognized as filled again.

Automatic activation and switch-over:

• The container that is first recognized as "full", is simultaneously selected and the drive is controlled accordingly.
• wf a container is empty, the system automatically switches over to the second container.
• If two containers are recognized as "full", it is possible to switch between the containers via the system display (CryoServer) or by pressing the illuminated pushbuttons (CryoModul).
• If both containers are empty or not detected, the fault displayed and registered as "Fault in nitrogen supply“ (in CryoServer). In CryoModul it can be selected whether the collective fault message is triggered.

Switching off the nitrogen supply:
A safety shut-off valve must be connected upstream to switch off the LN2 supply using the EMERGENCY STOP button or in the event of an oxygen shortage (CryoServer).